This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project
to make the world's books discoverable online.
It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject
to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books
are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.
Marks, notations and other maiginalia present in the original volume will appear in this file - a reminder of this book's long journey from the
publisher to a library and finally to you.
Usage guidelines
Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing tliis resource, we liave taken steps to prevent abuse by commercial parties, including placing technical restrictions on automated querying. We also ask that you:
+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for personal, non-commercial purposes.
+ Refrain fivm automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the use of public domain materials for these purposes and may be able to help.
+ Maintain attributionTht GoogXt "watermark" you see on each file is essential for in forming people about this project and helping them find additional materials through Google Book Search. Please do not remove it.
+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner anywhere in the world. Copyright infringement liabili^ can be quite severe.
About Google Book Search
Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web
at|http: //books .google .com/I
^^. f7. /]. r]^u.
, w -'
I vS'V': .•:- '• j DUPLICATE
TO BE K£f
V
THE VIRGINIA JAMESTOWN EXPOSITION COMMISSION
MINERAL RESOURCES
VIRGINIA
THOMAS LEONARD WATSON, Ph. D.
Professor of Economic Geologj' in the Univenity of Virginia
J. P. Bill Coup*
THENEWYOm.
PUBLIC UBRARY
^AtrOR, UfiOX AMD
• « • • • • • •
• • •" •
• • * . • • •
• • • • *
• •• ::
• • • • • • •«
CONTENTS AND SCHEME OF CLASSIFICATION
Pagb
IIXUSTRATIOI78 ZlX
Pbetaoe zzix
Part I. Gknebal Geologt of VnomiA 1
Geographic position of Virginia 1
Surface features 1
The Coastal Plain province 8
Formations of Virginia Coastal Plain 4
The Piedmont Plateau province 6
The Appalachian Mountain province 7
Diversity of resources 16
Value of resources 16
Past n. BuiLDiifG Stoitbs; Cemknt and CciixirT Materials; and Clatb.. 16
I. BUIU)INQ AND (ONAMENTAX STONES 16
Introduction 16
Siliceous ciystalline rooks 17
1. GRANITES 17
Definition 17
Distribution of the granites 17
Mineral composition 18
Kinds of granite 18
Description of granite areas 19
The Petersburg area 19
The Richmond area 21
The Fredericksburg area 26 — ^
The Fairfax county area 28
The Nottoway-Prince Edward counties area 20
The Blue Ridge area 30
Unakite 30
2. SYENITE 81
3. GNEISSES 88
The Lynchburg area 88
The Fairfax-Alexandria counties area 84
Other gneiss areas 84
4- ^aOA SCHIST 85
Production 85
*• ^prappean rooks 86
Diabase and basalt 86
Diorite 89
Gabbro 40
References 40
IV CONTENTS AND SCHEME OF CLASSIFICATION.
Page
6. SLATE 41
Introduction 41
The Buckingham-Fluvanna counties belt 42
The Albemarle county belt 46
The Amherst county ( Snowden ) belt 47
The Fauquier county belt 49
The Prince William-Stafford counties belt 61
Production 51
References 62
7. SANDSTONES AND QUARTZITE8 52
General properties 52
General statement 53
The Coastal Plain region 54
The Juro-Cretaceous sandstones 64
Piedmont Plateau region 55
The older crystalline quartzites 55
The Newark ( Jura-Trias ) sandstones 58
The Appalachian Mountain region 59
Introductory statement 59
The Cambrian sandstones 60
The Silurian sandstones 61
The Devonian sandstones 61
The Carboniferous sandstones 62
Mississippian group 62
Pennsylvanian group 62
Uses 63
Production 64
References 64
8. LIMESTONES AND MARBLES 66
General properties, composition, and occurrence 65
Distribution in Virginia 65
The Coastal Plain limestones 66
The Piedmont Plateau limestones 66
The older crystalline limestones 67
General properties 67
Distribution, occurrence, and general characters 67
Marble 69
Verd antique marble 70
The Newark (Jura-Trias) limestones 73
The Mountain province (Paleozoic) limestones 73
The Shenandoah (Valley) limestone 74
The Chickamauga limestone 76
The Lewistown limestone 77
The Greenbrier limestone 80
Marble 82
Cave (onyx) marbles 83
CONTENTS AND SCHEME OF CLASSIFICATION. V
Page
Uses 83
Production 84
References 85
IL CEMEKT AND CEMENT MATERIALS 86
Introduction 86
Kinds of cement 87
Distribution of cement materials 89
Cambrian and Ordovician formations of northwestern Virginia 01
Lower Cambrian quartzites, shales, and sandstones 03
Shenandoah limestone group 93
Stones river formation 95
Chambersburg formation 96
Martinsburg shale group 99
Trenton shales 100
Trenton limestones 100
Utica shale 101
Eden shales and sandstones 102
Massanutten sandstime group 102
General geography and stratigraphy of central western Virginia 103
Details of localities in northwestern and central western Virginia.. 105
Winchester 105
Middletown 107
Strasburg 107
Woodstock and vicinity 109
Harrisonburg and vicinity 110
Wadesville 113
Riverton and vicinity 114
Mount Sidney and vicinity 115
Staunton 115
Lexington 120
Geology of southwestern Virginia 123
Major faults 123
General distribution of Cambrian and Ordovician strata 124
Stratigraphy 128
Cambrian formations 128
Russell shales 129
Rutledge limestone 129
Rogersville shale 129
Maryville limestone 130
Honaker limestone 131
Nolichucky shale 131
Cambro-Ordovician 131
Knox dolomite 131
Ordovician formations 133
Chickamauga limestone 133
Lenoir limestone 134
Athens shale 134
Yl OONTENTS AND 80HEMB OF 0LAS8IFI0ATI0N.
Page
Holston formation 135
Pttarisburg limestone 137
Moccasin limestone 139
Sevier shales 140
Bays sandstone 141
Clinch sandstone 142
Details of localities 142
Giles county 142
Tazewell county 142
Washington county 144
Smyth county 146
Scott and Russell counties 148
Lee county 149
Post-Ordovician cement materials 151
Lewistown limestone 151
General distribution . : 152
Stratigraphy and analyses 153
Details and localities 154
Craigsville 154
Covington 156
Missippian limestones 156
Greenbrier limestone 157
Pennington shale 158
Travertine deposits 159
Natural cement 160
Cement industry in Virginia 162
References 165
CULTS : 167
Definition and properties of clay 167
Origin of clay 168
Classification of clays 168
Rasidual clays 169
Sedimentary clays 172
The Coastal Plain clays 173
Economic value of the Coastal Plain clays 173
The Alexandria area and vicinity 174
The Fredericksburg area 175
The Wilmont area 176
The Layton area 177
The Milford area 177
The Richmond area 177
The Fort Lee area 180
Summary 181
The Curie's Neck area 181
The Chester area 182
The Bermuda Hundred area 182
The Petersburg area 183
CONTENTS AND 80HEMB OF 0LA88IFI0ATION. YU
Paob
The Broadway area 188
The City Point area 184
The Sturgeon Point area 184
' The Oldfield area 185
The Belfield area 185
The Norfolk area and vicinity 185
The Suflfblk area 186
Western Virginia 187
References 187
III. Non-Mktalug Minerals 188
I. KLBICENTS 188
Graphite 188
(General character 188
Occurrence 188
Distribution and localities 188
Uses 190
References 190
n. 8X7LPHIDES AIO) BVLPHABSEinDES 190
1. PTBITE 190
Composition and properties 190
Mode of occurrence 190
Distribution and localities 191
General geology of the Louisa and Prince William areas 191
Character and structure of the rocks 191
The ore 19$
General character and mode of occurrence 193
Composition of the pyrite 19d
Associated minerals 19d
Genesis of the ore-bodies 197
The Louisa and Prince William pyrite deposits 198
Louisa county 19S
Location 198
Historical 198
The Arminius mine 19^
The Smith mine 201
The Sulphur mines •. 201
Prince William county 202:
The Cabin Branch mine 202:
Methods of mining 204
Milling 205
Uses 206.
Production 20«.
References 207
2. PTRRHOTITE . / 20a
References 209*
vlii CONTENTS AND SCHEME OF CLASSIFICATION.
Page
3. absenoptbits; misfigkel; ob absenioal ftbitbs 210
Uses 211
References 211
All. HAIJDES 211
1. HAUTE; SODIUM CHLORIDE; OB COMMON SALT 211
The Mathieson Alkali Works 214
References 215
2. FLUOBITE ; OB FLUOBSPAB 215
Uses 216
References 215
IV. OXIDES 216
1. snjCA 216
Quartz 216
Chert 216
Diatomaceous earth 216
Origin and occurrence 217
Distribution 218
Uses 222
References 223
2. OOBUNDUM AND EMEBT 223
Corundum 223
Emery 224
Uses 224
References 224
3. OOHEB 226
Definition and properties 225
Distribution and localities 225
Description of individual deposits 226
Chesterfield county 226
Loudoun county 227
Page county 228
Rockingham county 229
Augusta coimty 229
Rockbridge county 231
Warren county 231
Uses 231
References 231
4. ILMBNITE; MENACCANITE; OR TITANIC IRON 232
6. BUTILE 232
General properties and occurrence 232
Distribution 232
Milling process ^ 234
Uses 234
References 235
CONTENTS AND SCHEME OF CLASSIFICATION. IX
Page 6. mai7gane8e oxides 235
Introduction 236
General occurrence 236
Kinds of ore 237
The Ck)a8tal Plain region 238
The Piedmont Plateau region 238
Introduction 238
Description of individual areas 239
Amherst county 239
Appomattox county 239
Buckingham county 239
Campbell county 239
The Piedmont manganese mine 240
Nelson coimty 242
Pittsylvania county 243
The Appalachian Mountain region 244
Introduction 244
Description of individual areas 244
Page county 244
Augusta county 246
Rockingham county 250
Botetourt county 251
Frederick county 252
Shenandoah county 252
Rockbridge county 253
Other Valley deposits 254
Methods of mining 255
Preparation of the ore 256
Uses 256
Production 257
References 258
7. MIITERAL AND ABTESIA17 WATERS 259
Mineral waters 259
Chemical analyses 261
Production 267
References 268
Artesian waters 268
Water horizons in eastern Virginia 269
Potomac 269
Pamunkey 270
Chesapeake 270
Wells in eastern Virginia 272
References 275
SILICATES 275
CONTENTS AND 80HEMB OF 0LAS8IPI0ATI0N.
Pagk
1. FEIDSPABS 276
Composition and character 276
Occurrence 276
Distribution 276
Uses 277
References 277
2. lacAS 278
General character and composition 278
Occurrence 278
Distribution and description 279
The Amelia county area 279
Amelia court-house district 280
General geology 280
Mines 282
The Jefferson mines 282
The Rutherford mines 282
The Berry mines 282
The Pinchback mine 283
The Jetersville district 283
The Schlegal mine 283
Uses 284
Production 284
References 286
3. ASBESTOS 286
General character and composition 286
Occurrence 286
Distribution 286
Uses 287
References 287
4. GABIOCT 287
Composition and properties 287
Distribution 288
Uses 289
References 289
6. TALC AND SOAPSTONE 289
Composition 289
Occurrence and origin 290
Distribution and localities 290
Talc 290
Soapstone 290
Fluvanna and Buckingham counties 290
Albemarle, Nelson, Campbell, Bedford, and Franklin counties.. 291
Amelia county 291
Louisa county 292
Fairfax county 292
oontbhis and s0hbic8 of olabbitioltion. xl
Pub
QrtjKM county 292
Carroll, Floyd, and Patrick oonntiM 293
Henry county 2SS
Albemarle- Nelson conntiea Boapatone belt SOS
UiCB Z06
Production S9fl
References S06
4. ruu^aa kaxtb 298
Definition and propertiea 298
Diatribution and localities 297
Uaes 2K
Referencea 897
n. HiofiATEs ADD ronaBTATss 298
1. OOLDUIOTE 298
2. BTPTUTB 298
8. WOLTKAIUTE 209
RefereacM 290
m. FBOSPHATES 299
1. AFATITE AND FHOBPBATIO UABt, 299
Nelsonite (phoaphkta rock) 300
Nelson county 800
Roanoke county 301
Pebble phoapliat« 302
2. DDTBEKITB 302
3. STBtnaiTE 303
4. HONAZiiv 303
Beferencee 303
Tin. niSATEs 304
I. niTEB; POTASSIUM lermiTK 304
General propeitict and occurrence 304
Distribution 304
References 306
IX. SULPHATES 306
1. KAKTK; heavy SPAS 306
Composition and properties 306
Hietorical 306
Distribution 307
General occurrencs 307
The TriaBsic area 308
The Piedmont Plateau area 809
The Cam pbell-Pittay Ivan ia counties area 309
Other prospects 314
:i C0!eTH3rT3 aXD KCmEHK l^P LAdfiBEHUZmir:
finite :r t <vtirngtoe. ['he Ljuidft t'liiiKCv irea
1
Plus U
TTia ortfcrrt 'juinrr rua. '.13
riia inpiiiaimuLii. -Mousquq rqsnon. . \'IQ
'. nrrrxtmttion . . . :3a
i )«:H»nnci{>n i r ! iKtirrdnaai .itesut. . 'JO
\*vma ivnuaarr ;a9
\'«.4ttmsrcoai i 'iuner
In.^MHi .toa ^ojBwpii auimeH
^IMh4Mt« r rixmiBr. -^SS'
I'fSfSEUEHtlCill .!^
\«» ]m-
i'mriiinRCin 521'
^^narxi roBerceH. ".'St'
' >ttcm 1. na rtffniTx:a!ic« .;23-
- r«mfir9Ei ceniome aMLnogoa: r le -(Mitnwesft 'Irtimm («poMKa. ^29^
^[liiaEiur c«vfMec»!ODiXH. >29
"^«» -I^-
r^mriTscdCin "^.
: v4t Vl'tflUflSt !«15
X. .rm«»R?iBai»!sr5i ija-
t'OAx; vxo irt^ TpaowrcTs. IM-
. COAX^. .138
riistanroi >S8
DLitTibmion • i 'tiit^'iaj. 5213-
[Tie Pieamoiit .rovme^* 333
!1ic t JctnooiMi lOfti hftam )S9-
.liKtiinnai ... JlU'
Tesnnii .emuxy c tie Jhskm> . )4WI«
'1i^ itwi -■cit£->[ 'iici -ftaui. .!t4i
•.iiiivivsii . [ tMi :D7in '3ft 'MUuiiinjimi tAUi. i^'
ijfetnn 1. 1 - ift rtiBn. j^.-
DlMR !!<$•
'Hi*- mpoiaeeiim Jfauntajn. >n»vinee. )^?~
. ^f9Ar ' 'kraoQnaitnis )IiaiMtit»pfimii/ <MiR> ^tj"
r^c- rmratiun: -^ftiifi .iif»r»A. >tl~
.' f (UtMucsc imntTk 'jl?"
CONTENTS AND SCHEME OF CLASSIFICATION. Zlll
Page
The North River coal field 348
Augusta county 348
The North Mountain coal field 348
Botetourt county 348
The Montgomery-Pulaski counties field 349
The Bland-Wythe counties field 352
The Carboniferous ( Pennsylvanian ) coals 353
Location and importance 353
Geologic relations 363
The age of the coal-bearing rocks 353
Stratigraphy 354
Structure 356
Character of the coal 356
The Pocahontas or Flat-top coal field 359
Introductory statement 369
Operations 359
The coal 360
Introduction 360
Coals of the Pocahontas formation 362
Coals of the Welch (Clarke and Quinnimont) formation 363
Coals of the Dismal formation 364
Coals of the Sequoyah and Tellowa formations 364
The Big Stone Gap coal field 364
Location and importance 364
The coal 366
Operations 367
The eastern portion of the field 367
Introduction 367
The Edwards seam 368
The Upper Banner seam 368
The Lower Banner seam 368
The Kennedy seam 369
The Imboden ( ?) seam, so-called 369
The Jawbone seam 369
Coals in the vicinity of Big Stone Gap and the western
portion of the field 370
Introduction 370
The Imboden seam 371
Seam just beneath the Gladeville sandstone 372
Coals of the Wise formation 372
Methods of mining 373
Production 375
References 376
2. OABBONITE ( NATURAL COKE) 378
References 379
3. COKE 380
Analyses of Virginia coke 381
4. 6A8, TAR, AND AMMONIA (BY-PRODUCTS OF COKE WORKS) 383
XIY CONTENTS AND 80HSMB OF 0LAS8IFI0ATION.
Paok
XI. MZSOELLAlfSOUS 386
1. OmC MIITKBALB 386
Distribution and localities 386
Diamond 386
Quartz (amethyst) 386
Garnet 386
Beryl 387
Apatite 387
Allanite 387
Elyanite 388
Fluorite 388
Feldspar 380
Microlite 380
Columbite 300
Helyite 300
References 301
8. SAITD 302
Glass sand 303
Molding sand 304
Building sand 306
Production 306
3. XABLS 306
Definition and properties 306
Origin and occurrence 306
Distribution and localities 307
The Coastal Plain region 307
Greensand marls 307
Calcareous marls 308
The Valley Region 300
Uses 400
References 400
4. lOZXSTDNSS (BUHB8TOITE8) 401
Production 401
Past IV. Metaujc MnrEBALS qb obbs 402
I. noir 402
Historical 402
Minerals and ores of iron 403
Impurities of iron ore 406
Origin of iron ore 407
Classification of Virginia ores 407
Oriskany ore 408
Limestone limonite ores 410
Blue Ridge limonite ore 414
Fossil hematite 416
Blue Ridge hematite 418
OONTBHTB Aim 80HB1CB Of OLABSIVIOATIOK. XT
Ftam
^rite goAsan *^*
Pyrrhotito goaaan and pjrrbotite *1*
Piedmont iiiAgiietiU* *21
Limutoue magnetite ***
Titaniferous magnetite **2
Qeologieal dietribution *^
Geographical distribution *^
Individual mines ***
Counties west of tlie Blue Ridge <2»
Frederick county **•
CUrke county *»
Warroi eonnty *W
Shenandoah ooun^ ***
Page county "'
RockiDghain county *M
Augusta county ***
Rockbridge county *"
Highland county *•«
Bsth county ***
AU^any county **8
Botetourt county **2
Craig county ***
Roanoke county ***
Montgomery county **'
Giles county **t
Pulaald county **8
Wythe county 401
Smyth coun^ **>
Waahinglon county 481
Bland county 488
TaMwell county 46B
Russell county 4M
Scott county 4M
Buchanan and Dlekeneon counties *M
Wise county 463
Lee county 466
Piedmont counties 4M
LoudouD coun^ 468
Stafford county 468
Spottsylvanla county 468
Louisa county 469
Alt)eniBrI« county 469
Nelson county . .'. 469
Buckingham county 470
Mecklenburg county 4T0
Amherst county 470
Appomattox county 471
XVI CONTENTS AND SCHEME OF CLASSIFICATION.
Page
Campbell county 471
Bedford county 471
Pittsylvania county 472
Franklin county 474
Patrick county 474
Henry county 476
Floyd county 475
Carroll county 475
Grayson county 476
Coastal Plain counties 477
List of iron mines in Virginia 477
Methods of mining 479
Ore dressing 486
Uses 486
Production 487
References 488
n. ooppElt 491
General statement 491
Distribution of the ores 492
Geographic distribution 492
Geologic distribution 492
The Virgilina district 494
Introductory statement 494
General geology and petrography 494
Kinds and occurrence of the ores 494
The veins 495
Description of the mines 496
Historical 496
Individual mines 496
The Keysville area in Charlotte county 500
The Buckingham county deposits 601
The Albemarle county deposits 502
Amherst county deposits 503
The Blue Ridge copper deposits 503
Location and history 503
Geology 504
Kinds and mode of occurrence of the ores 505
Description of the mines 506
Warren county 506
The Bentonville-Overall district 507
Rappahannock county 508
Page county 509
Madison county .' 509
Greene county 510
The southwest Virginia region 611
The "gossan load" of Floyd, Carroll, and Grayson counties 511
General statement 611
CONTENTS AND 80HS1CS OF 0LA88IFI0A7I0N. ZTU
Page
General geology 611
General character of the vein 612
Description of mines 614
Carroll county 614
Grayson county 617
Floyd county 617
Franklin county 617
The copper ores of the red beds of the Triassic 618
Loudoun county 618
Culpeper county 618
Orange county 618
References 610
m. ZW 0 AND LEAD 620
Historical 620
Distribution 620
General geology 621
The ores and associated minerals 623
The lead ores 623
Galenite 623
Gerussite 623
The zinc ores ^ 624
Sphalerite 624
Smithsonite 624
Calamine 626
"Buckf at" 626
Associated ores 626
Associated minerals 626
Alteration of the lead and zinc ores 527
Mode of occurrence 627
The sulphide ores 627
The oxidized ores 528
Relation of the ores to geologic structure 529
Origin of the ores 529
Description of the mines 530
The Great Valley region 530
Roanoke and Botetourt counties 530
Montgomery county 530
Pulaski county 531
Wythe county 531
Smyth county 540
Russell county 541
The Piedmont region 542
Albemarle coimty 542
Methods of mining the ore 544
Preparation and smelting of the ores 545
The Bertha zinc smelting plant 546
Spelter , 547
References 547
XYIU CONTENTS AND SCHEME OF CLASSIFICATION.
Page
iv. gold and silver 549
Historical 549
Distribution 549
General geology 551
The country rocks 551
The veins 551
The gangue minerals 552
Description of mines 553
Fauquier county 553
Stafford county 553
Culpeper county 554
Spottsylvania county 554
Orange county 555
Louisa county 557
Fluvanna and Goochland counties 659
Buckingham county 562
Halifax county 563
Montgomery and Floyd counties 564
Production 564
References 566
V. TDX 567
Mineralogical and chemical character 567
Historical 568
Occurrence 568
Other localities 577
References 577
VI. NICKEL AND COBALT 578
General statement 578
The Floyd county area 580
Reference 582
ILLUSTRATIONS.
Plate Faodto Paqb
I. High and low wateb stages in Jahes biyeb at Richmond.... 4
Fig. 1. — Flood stage in James river 4
Fig. 2. — ^Low water stage in James river 4
II. Granite quabries in the Petebsbubg and Richmond abbab .... 20
Fig. 1. — Cook's granite quarry, north of Petersburg 20
Fig. 2. — Granite quarry near Richmond 20
III. Map of the Richmond granite abea showing location or
QUABRIES 23
IV. Granite quarries in the Richmond arba 24
Fig. 1. — McGrowan quarry south of Richmond 24
Fig. 2. — Granite quarry near Richmond, showing jointing 24
V. Granite quarries in the Richmond arba 20
Fig. 1. — Granite quarry near Richmond, showing joint structure 20 Fig. 2. — McGowan quarry near Richmond, showing gneiss in- clusion 20
VI. Granite and gneiss quarries 84
Fig. 1. — ^McGowan quarry and dressing yard 84
Fig. 2. — Gneiss quarry southeast limits of Lynchburg 84
VIL Slate quarries, Arvonia, Buckingham county 42
Fig. 1. — Slate quarry in the Arvonia area 42
Fig. 2. — Slate quarry in the Arvonia area 42
VIII. Slate quarries, Arvonia, Buckingham county 46
Fig. 1. — Williams Slate Company's quarry, Arvonia 46
Fig. 2. — Abandoned slate quarry, Arvonia 46
IX. Slate quarries, Snowden, Amherst county 48
Fig. 1. — Williams Brothers slate quarry, near Snowden 48
Fig. 2.— Same as Fig. 1 48
X. Crystalline schist and marble quarries 70
Fig. I. — Quarry in crystalline schist, Faber, Nelson county 70
Fig. 2. — Opening in marble, Grayson county 70
XI. Map of the Greater Valley region or Virginia, showing dis- tribution OP Obdovician 01
XII. Natural Bbidge, Rockbbidge county 94
XIII. Anticlinal fold in Massanutten sandstone 102
XIV. House Mountains and folded Massanutten sandstone 103
Fig. 1. — House Mountains, Rockbridge county 103
Fig. 2. — Fold in Massanutten sandstone 103
XX ILLUSTRATIONS.
Plate * FAcmo Pagb
XV. OvurruHUST fault aih) liicestone decay 110
Fig. 1. — Overthrust fault in Tuscarora sandstone, near Panther
Gap 119
Fig. 2. — Fields of residual decay near Natural Bridge 119
XVI. Natural Bridge limestone 121
Fig. 1. — Upper part Natural Bridge limestone weathering into
chert bands 121
Fig. 2.--Same as Fig. 1 121
XVH. Lower Cambrian quabtzite and Sherwood formation 123
Fig. 1. — Balcony Rock, composed of Lower Cambrian quartcite.
Balcony Falls 123
Fig. 2. — Cliff of Sherwood dolomite, near Sherwood, Natural
Bridge station 123
XVIII. BuENA Vista shales and Lewistown limestone 149
Fig. 1. — Buena Vista, Virginia 149
Fig. 2. — Quarry in Lewistown limestone, Longdale 149
XIX. Anticlinal fold in Lbwistown limestone 152
XX. Portlaivd cement plant, Fordwick, Augusta county 163
XXI. LiMESTONB WEATHERING, BRICK PLANT AND CLAT PIT 169
Fig. 1. — Weathering of limestone, near Christiansburg 169
Fig. 2.— Oldfield Brick Go's plant, Oldfield 169
XXII. Kaolin pit and washing plant, Henrt county 170
Fig. 1. — Kaolin pit near Oak Level, Henry county 170
Fig. 2. — Kaolin washing plant near Oak Level, Henry county. . . 170
XXIII. Map of the Virginia Coastal Plain, showing clay localities 174
XXrV. The Powhatan Clay Manufacturing Co's plant, Clayville.. 178
XXV Clay bank and brick yard on Appomattox river 183
Fig. 1. — Heeler's brick yard at Broadway on the Appomattox
river 183
Fig. 2. — Heeler's clay bank at Broadway on the Appomattox river 183
XXVI. Washington Hydraulic Press Brick Co's works, Virginia 186
XXVII. Pybite mines in Virginia 200
Fig. 1. — Arminius pyrite mines, near Mineral City 200
Fig. 2. — Cabin Branch pyrite mine, near Dumfries 200
XXVIII. Pybitb lenses, Louisa county 201
Fig. 1. — Exposure of pyrite ore-body at the Sulphur mines, Louisa
county 201
Fig. 2.--Same as Fig. 1 201
XXIX. Pyrite mines in Virginia 206
Fig. 1. — Sulphur mines, near Mineral City 206
Fig. 2. — Shaft and dump at Sulphur mines, near Mineral City.. 206
ILLUSTRATIONS.
XXXVI.
Plate Faoih g Paqb XXX. Ptrrhotite mine, "Great Gossan Lead," Carboll ooumr 208
XXXI. Map of workings, U. S. Arseihc Miiocs Co., Rewalo, Flotd
COUNTY 210
XXXII. Arsenic and nickel mines, Floyd county 211
Fig. 1. — ^Milling plant and mines, U. S. Arsenic Mines Ck)., near
Terry's Fork 211
Fig. 2. — Lick Fork nickel opening, near Hemlock, Floyd county 211
XXXIII. Salt wells and Saltville 212
Fig. 1.— Salt wells, Saltville 212
Fig. 2. — Saltville, Washington county 212
XXXIV. Mathieson Alkali Works and salt wells, Saltville 214
Fig. 1.— Mathieson Alkali Works, Saltville 214
Fig. 2.— Salt wells and valley at Saltville 214
XXXV. Diatomaceous earth, Wilmont 221
Fig. 1. — Diatomaceous earth overlain by Pleistocene clay at Wil- mont 221
Fig. 2. — Bluffs of diatomaceous earth southeast of Wilmont 221
RUTILE OPENINGS, ROSELAND, NeLSON COUNTY 234
Fig. 1. — Openings for rutile along Tye river, Roseland 234
Fig. 2.— Same as Fig. 1 234
CrIMORA manganese milling plant AND MINES, AUGUSTA COUNTY 246
Fig. 1. — Crimora manganese milling plant, Crimora, Augusta
county 246
Fig. 2. — Crimora manganese mines, Crimora, Augusta county . . . 246
Mineral springs in Virginia 259
Fig. 1. — The New Homestead, Virginia Hot Springs, Bath county 259 Fig. 2. — Buffalo Lithia Springs, Mecklenburg county 259
XXXIX. Sections indicating water-bearing horizons in eastern Virginia 268
XL. Map of eastern Virginia, showing distribution of underground
waters 269
XLI. Mica mine and dump, Amelia county 283
Fig. 1. — Pinchback mica mine, near Amelia court-house 283
Fig. 2. — Dump of scrap mica, near Amelia court-house 283
XLII. Map showing location of soapstone quarries in Albemarle and
Nelson counties 293
XLIII. Soapstone quarries. Nelson county 294
Fig. 1. — Soapstone quarry. Nelson county 294
Fig. 2. — Soapstone quarry, Nelson county 294
XLIV. Soapstone quarries. Nelson county 295
Fig. 1. — Schuyler Soapstone Co's plant, Nelson county 295
Fig. 2. — National Soapstone Co's quarry. Nelson county 295
XXXVII.
XXXVIII.
ILLUSTRATIONS.
XLV.
XLVI.
XLVII.
XLVIII.
XLIX.
L.
LI.
LII. LIII. LIV.
LV.
LVI.
LVII. LVIII.
LIX. LX.
LXI.
Facivo Pagb
soapstoxe quarkies dc auftmablk comt 296
Fig. 1. — Alberene soapstone qumrry, Albemarle eoimty 296
Fig. 2. — Alberene soa|>5tone qumrrj, Albemarle coimtj 296
SoAPSTo?nc a:^) umestoxe quasbies nc Vmccoa 297
Fig. 1. — A recently opened soapstone quarrr in Nelson county. . 297 Fig. 2. — Limestone quarry of the Mathieaon Alkali Works, near
Saltville " 297
Barite mhtes, Prijtce Whjxam couxtt 308
Fig. 1. — Barite mine near Catlett station 308
Fig. 2. — Shaft at barite mine near Catlett station 308
Barite aivd gypsum miites ix Virginia 314
Fig. 1. — Bennett's barite mine, Pittsylvania county 314
Fig. 2. — Gypsum opening, near salt plant, Saltville 314
Barite mill at Bristol 324
Barite mux. at Richla:«)s 326
Gypsum mutes ai?d mill, Washi>'gton county 328
Fig. 1. — Saltville valley at Plasterco, showing mined gypsum
masses 328
Fig. 2. — Buena Vista Plaster and Mining Go's plant, Plasterco.. 328
Map of the salt and gypsum deposits in southwest Vxroinia. . 330
Map of the Richmond coal basin 340
Goal mines and breaker of the Virginia Anthracite Goal Gom-
pany, near Ghristiansburo 361
Generalized sections from differfnt p<MrnoNs of the Big Stone
Gap coal field 355
Geologic structuhe sections, southwestern and northern Vir- ginia 366
Block of coal, Pocahontas coal field, Tazewell county 360
Goal incline and tipple. Big Stone Gap coal field 364
Fig. 1.— Clinchfield Coal Go's incline, Dante 364
Fig. 2. — Granes Nest Goal and Goke Go's tipple, Tom's Greek... 364
Seaboard Goal Go's tipple. Seaboard 368
Goal mining plant, tippue, crusher, and coke ovens. Big Stone
Gap coal field 371
Fig. 1. — Stonega coal mining camp 871
Fig. 2. — Coal tipple, crusher, and coke ovens, Stonega 371
Goal tipple and coke ovens, Big Stone Gap coal field 380
Fig. 1. — Gsaka No. 1 coal tipple 380
Fig. 2. — Goke ovens, Osaka 380
ILLUSTRATIONS.
mil
LXII.
LXIII.
LXIV.
LXV.
LXVI.
LXVII.
liXVIII.
LXIX.
LXX.
LXXI.
LXXII. LXXIII.
LXXIV.
Fagiito Page
Coke ovens. Bio Stone Gap goal field 382
Fig. 1. — Coke ovens, Stonega. 382
Fig. 2. — Coke ovens, Imboden 382
Map of pabt of Viboinia, showing location of pbinoipal ibon mines, etc 429
Ibon iones in the Blue Ridge region 436
Fig. I. — Buena Vista iron mine 436
Fig. 2. — Dixie iron mine 436
Ibon obe outcbops and washeb, Blue Ridge beoion 443
Fig. I. — Adams Peak looking southwest, etc 443
Fig. 2. — The Gnibb iron mines washer 443
Ibon (hematite) mines, Blue Ridge begion 445
Fig. 1. — Wood iron mine 446
Fig. 2. — Arcadia iron mine 445
Ibon Gate gap and Obiskant ibon mine, Alleghany county .... 446
Fig. 1. — Iron Gate gap of Jackson river through Rich Patch
Mountain 446
Fig. 2. Oriskany iron mine 446
Mining bt milung, New Riveb-Cbippu: Cbeek ibon ore abea . . . 450
Fig. 1. — Locust Hill iron mine 450
Fig. 2. — Reed Island iron mine 450
Hydraulic mining in New Rtvbb-Cbipple Cbeek ibon obe abea . . 455
Fig. 1. — Hematite mine! 455
Fig. 2. — Rich Hill iron mine 455
Ibon mines, Pittsylvania county 473
Fig. 1. — Shaft house of the Barr magnetic mine, near Pittsville 473 Fig. 2. — Barr limonite mine, near Pittsville 473
CoppEB ore, Virgilina district, Virginia-North Carolina 495
Fig. 1. — Copper ore (chalcocite and bomite in quartz) Virgilina
copper district 495
Fig. 2.— Same as Fig. 1 495
Map of the nobthebn Blue Ridge coppeb distbict, showing loca-
CATioN of mines 503
COPPEB MINES IN THE NOBTHEBN BLUE RiDGE BEGION 509
Fig. 1. — Shaft house, ore dump, and basalt cliffs, Madison county 509 Fig. 2. — Shaft house, Virginia Consolidated Copper Co's mine, near Ida 509
Blue Ridge and shaft of coppeb mine 510
Fig. 1. — Blue Ridge from Virginia Consolidated Copper Co's mine,
near Ida 510
Fig. 2. — Shaft No. 3 High Hill copper mines, Halifax county. . . . 510
XHV ILLlTSTKATIONfe.
LXXV. Ptbehoiite mhibb cxmvtainikg ooenx. '"(^cat Gobbak Iau),"
Casboll cjormr 516
Fig. 1. — Bhaft at Betty Baker mine, west nde of Toad 516
Tig. 2. — Open cat at Betty Baker mine, CSairoll eonnty 516
LXXVI. LnixsToia. wbathzbing. zinc lONEb. Wtthf cxjunty o2B
Fig. 1, — ^Limestone "chinmeys'" at Bertha xinc mines 52fi
Fig. 2. — Open cut shoiviog limestcnie **chiiiiiieyp" at Bertha sac mines 526
m
LXXVIl. LniXSTONE WEATHEBIKG. ZTNC MINBS, WtTHE COCWTY 532
Fig. 1. — ^\eatheTed limestone surfaee in open ent, Bertha zinc mine> 632
Fig. 2. — A\eathered limestone surface. Anstinville zinc and lead mine?< S32
LXXVIII. Zinc muxjnc. plant anp uicBflTONE **(»iinfEYs." Wtthe oouftt 536
Fig. 1 . — Zinc milling plant at Atwtinvilte 536
Fig. 2. — ^Weathering of limestone into pinnacled surface. *'chim- nevF" 536
LXXIX. 2iN(^ auEXTiNCi plant and niKNACt, PniASKi frC7
Fig. 1 . — Zinc smelting plant of Bertha Mineral Oo 547
Fig. 2. — Dismantled ainc furnace 647
LXXX. Map Oft principal ooid belt in Viboinia, showing nEfenxmunoN
oi mines 563
LXXXi. C«nu»-iiKAaiN<; qi;abt7 veins, Obange oouim 566
Fig. 1. — (nitcrov of gold-hearing quartz vein on the former **ClaTk
lYact" 556
Fig. 2. — fiold-hearing quartz veins, s portion of **&noke-Hoiiee lifidgr" 665
JJCXXIJ. ftou» ani» coppKit-maAaiNCi vKiNts ant> cmx., Okanqi: oditntv 666
Fig. 1. — lOxpoAUTo of gold and copper-hearing veins. ** American
Trurt" 566
Vi^' • — (iciU\ and copper- hen ring quart.? ore 666
LXXXI U. (-lOHi MliJ.rN<. PIJINT ATC1> WTNT OPVNING. Fm^vaNNA AWI) OKAKGK
r<»i NTI1«>^ 661
Fig I --Hughp« gold niitUng pUni. near Fork Union. Fluvanna
ri unity 661
I' ir '.' opci) ml. 41 tov ff^t i^mith of the old Virginia Mining
( ■(• «■ xiiiifi 661
ILLQSTBATIONS. ZXY
Figure Page
1. Sketch map of Virginia showing physiographic provinces 2
2. Diagrammatic section illustrating relationship between the Piedmont and
Coastal Plain formations 3
3. Generalized section of area covered by the Harper's Ferry folio 8
4. Generalized section of area covered by the Staunton folio 9
5. Generalized section of area covered by the Tazewell folio 11
6. Generalized section of portion of area covered by the Bristol folio *. 13
7. Map showing location of granite quarries in the Petersburg area 10
8. Relations of blue to gray granite at the Netherwood quarry 22
9. Map showing location of granite quarries in the Fredericksburg area 27
10. Map of the Arvonia slate area, Buckingham county 43
11. Map showing location of Snowden slate quarries, Amherst county 47
12. Map of the Fauquier county slate area 49
13. Structure section from the Blue Ridge to Little North Mountain 106
14. Structure section across Massanutten Mountain syncline 106
15. Structure section from Strasburg to 1 mile west of Strasburg Junction. .. 106
16. Map of cement materials of northwestern Virginia 108
17. Map of Valley of Virginia from Woodstock to Staunton Ill
18. Structure section from the Blue Ridge to Little North Mountain, about
latitude of Harrisonburg 112
19. Structure section in the vicinity of Lexington 112
20. Map of Valley of Virginia from Staunton to Natural Bridge 116
21. Structure section south of Stokesville 120
22. Structure section in the vicinity of Zack, and Little North Mountain 120
23. Structure section from Holston Mountain west to Cumberland Mountain . . 125
24. Structure section from Glade Spring to Saltville 125
25. Map of cement materials of southwest Virginia 143
26. Structure section from Bristol east to Holston Mountain 146
27. Structure section from Powell Mountain to Cumberland Mountain 145
28. Map of cement materials of New River district 147
29. Sketch map of Virginia showing pyrite and pyrrhotite belts 192
30. Plan of pyrite lenses in Louisa county 193
31. Plan of pyrite lenses at Sulphur mines, Louisa county 194
32. Plan of pyrite lens, showing pyrite stringers in the hanging- wall 195
33. Plan of portion of pyrite lens in Cabin Branch pyrite mine 196
34. Map showing location of pyrite mines in Louisa county 199
35. Plan of pyrite lens on the 620-foot level, Arminius mine 200
36. Map showing location of Cabin Branch pyrite mine 203
37. Plan of part of pyrite lens at Cabin Branch pyrite mine 204
38. Map showing location of rutile and nelsonite. Nelson county 233
39. Section showing occurrence of manganese ore in residual clay 237
40. Ground plan of manganese deposits, Crimora, Augusta county 247
41. Sections through Crimora manganese deposits 247
42. Map showing location of mica mines in Amelia county 281
43. Section showing relations of nelsonite to the enclosing schists 301
44. Sketch map of Virginia showing worked areas of barite 306
45. Map showing location of barite mines in Piedmont Virginia 310
XXVI ILLUSTRATIONS.
Figure Paqb
46. Columnar section at Bennett barite mine, near Toshes 312
47. Section in Bennett barite mine, near Toshes 313
48. Structure section at Saunders manganese and barite mines, near Evington,
Campbell county 318
49. Section showing occurrence of barite in limestone residual clay 321
50. Map and sections of the Russell-Tazewell counties barite belt 323
51. Section across the Holston and Saltville valleys 320
52. Map of Virginia showing the coal areas 337
53. Geologic section of Richmond coal basin 341
54. Map showing location of principal coal mines in the Montgomery- Pulaski
counties coal field 350
55. Diagram showing panel system of coal mining 373
56. Cross section of Alleghany Mountain anticlinal showing Oriskany ore, etc. 409
57. Diagram illustrating the occurrence of "mountain ores'' in the New River-
Cripple Creek area 411
58. Diagram illustrating the relations of the New River-Cripple Creek limonite
to the lower beds of the Shenandoah limestone 412
59. Diagram illustrating occurrence of limestone limonite in southwest Vir-
ginia 413
60. Section showing the occurrence of Blue Ridge limonite ore 415
61. Diagrammatic cross section of the "'Great Gossan Lead" 420
62. Generalized columnar section of Paleozoic strata showing distribution of
iron ores 424
63. Generalized section across the Valley and Alleghany Mountains in Virginia
showing position of iron ore, etc 426
64. Sketch map of Virginia showing the principal iron ore areas 427
65. Profile of part of the Blue Ridge at the Dixie iron mine 437
66. Section showing the geologic relations of the iron ore in the Holston mine 462
67. Geologic structure section across Poor Valley Ridge, etc 465
68. Diagram of the Ewing iron mine 467
69. Section in the Barr magnetite mine 473
70. Diagram illustrating milling of iron ore from face of slope 480
71. Diagram illustrating milling of iron ore (first stage) 481
72. Diagram illustrating milling of iron ore (later stage) 481
73. Section showing geologic relations of Oriskany ore and method of working
deep-lying ore 483
74. Diagram illustrating method of mining in steeply dipping beds, etc 484
75. Diagram illustrating method of mining in flat- lying beds, etc 485
76. Map of Virginia showing distribution of copper areas 493
77. Diagram illustrating vein structure in the Virgilina copper district 495
78. Diagram of High Hill vein at shaft No. 4 496
79. Map of the Virgilina copper district, showing location of principal mines 497
80. Concentrating system at the Durgy mine, Virgilina copper district 499
81. Brecciated epidotized basalt with ore and quartz, Stony Man peak 504
82. Part of basalt shell filled with epidote and rimmed with ore, Warren
county 505
83. Quartz with native copper, Fletcher, Greene county 506
ILLUSTRATIONS. XXYU
Figure Page
84. Asbestiform serpentine with native copper, Ida, Page county 506
85. Profile of "Gossan Lead," Carroll county, from Betty Baker mine to the
Kirkbride mine 512
86. Pyrrhotite interleaved with talc. Chestnut Yard, Carroll county 513
87. Pyrrhotite with columnar hornblende. Chestnut Yard, Carroll county 513
88. Map of Carroll county pyrrhotite area, showing location of mines 515
89. Map showing distribution of lead and zinc ores, Virginia and Tennessee. . 521
90. Section of the Bertha zinc mines, showing geologic relations of the ore and
rocks 533
91. Section at the Bertha zinc mines, showing the mode of occurrence of the
ore and the method of mining 534
02. Section at the Austinville lead and zinc mines, showing geologic relations
of the ore and rocks 535
93. Sketch map of the Austinville lead and zinc mines, Wythe county. ...... 537
94. Limestone breccia zinc ore from Cedar Springs, Wythe county 538
95. Limestone breccia zinc ore from Cedar Springs, Wythe county 539
96. Zinc-lead ore from Sugar Grove, Smyth county 640
97. Zinc-lead ore from the Albemarle zinc and lead mines, near Faber 542
98. Map of Virginia showing the principal gold ore areas 550
99. Map showing location of nickel and arsenic mines, Floyd county 579
100. Groimd plan showing location of nickel openings, near Hemlock, Floyd
county 580
101. Section showing structural relations of the rocks at the nickel mine in
Floyd county 581
%
PREFACE
This volume, Mineral Resources of Virginia, authorized by the (Jovernor of Virginia and the Virginia Jamestown Exposition Commission, has been published in order to direct attention to the economic value, location, and commercial possibilities of Virginia's varied mineral wealth. The evidence here presented shows that the State is well supplied with a great variety of mineral resources, many of which are being rapidly developed. There is probably no state in the Union of the same area as Virginia that can show a greater diversity in geologic resources. This most important fact taken in connection with the mildness of the climate, which permits of a long season of outdoor work, and the cheapness of labor, are conducive to a very extensive mining industry. The total value of production of the mineral resources of Virginia for the year 1906 has been estimated at $30,000,000.
At the July (1906) meeting of the Virginia Jamestown Exposition Commission, it was agreed that a handbook illustrative of the vast mineral resources of Virginia was a necessity. The writer was accordingly authorized to prepare a handbook setting forth, as completely as our present knowledge permitted, the vast and varied mineral resources of the State. He was further authorized to devote several months in the field to a studv of the mineral resources in those portions of the State where information was most needed for the purpose of collecting the necessary data for this volume. The work has proved far more exacting than was at first con- templated, in that the widely scattered literature on the geology of Virginia liad to be overhauled in the preparation of the volume.
The principal sources of information, forming the basis of this volume, are "A Reprint of the Geology of the Virginias," by Professor William Barton Rogers, State Geologist of Virginia from 1835 to 1841, inclusive; 'The Virginias," a monthly journal edited by Major Jed Hotchkiss from 1880 to 1885, inclusive (six volumes) ; the numerous excellent publications of the United States Geological Survey; and the published and unpub- lished reports of the recent Geological Survey of Virginia conducted jointly for two years by the Board of Visitors of the Virginia Polytechnic Institute and the State Board of Agriculture. In addition to the above publications mnch valuable information has been obtained from general treatises on special geologic subjects, such as from Merrill's "Non-Metallic Minerals,"
PREFACE. XXXI
careful field study of the areas by the authors, made possible by the recent (Geological Survey of Virginia in cooperation with the United States Geological Survey, especially in the study of the Cement and Cement Materials by Doctor Bassler, and of the Iron Ores by Professor Holden. The contribution on Clays by Professor Eies was extracted by him from his report on the Virginia Clays published as Bulletin No. II of the Geological Survey of Virginia.
The general interest manifested in the work by many people in the State, especially the mine and quarry operators, and by many residing outside of the State but who have mining interests in Virginia, aided greatly in the preparation of this volume. To all of these the writer is under deep obligation for many courtesies extended. Acknowledgments are also due to Messrs. Joel H. Watkins and Henry F. Day, former students in geology at the Virginia Polytechnic Institute, for valuable services rendered. Mr. Watkins prepared the line drawings and maps illustrating this volume. Mr. Day assisted the writer in the field during a part of the summer of 1906.
To Governor Claude A. Swanson and the members of the Virginia JamestowB Exposition Commission, especially Hon. W. W. Baker of Chesterfield county, who made this work possible and have rendered every assistance during its preparation, the writer makes most grateful acknowl- edgment
With a full realization of the deficiencies in this volume, it is published with the hope that it will supply a widespread and increasing demand among our people and among others for information on the mineral resources of Virginia.
Thomas Leonard Watson.
University of Vtr^inta, Charlottesville, September SO, 1907,
PART I.
GENERAL GEOLOGY OF VIRGINIA
OEOOEAPHIC POSITION OF VISOINIA.
The State of Vir^nia is situated on the Atlantic slope of the Appalachiair Mountains, halfway between Maine and Florida. It is included between the parallels 36° 31' and 39° 27' north latitude, and between the meridians 75° 13' and 83° 37' west longitude, and extending from the sea-coast west- ward beyond the Great Valley to the Alleghany Front. The extreme length of the State from the Atlantic border to Kentucky is 476 miles, and greatest width from north to south is 192 miles; its area is 42,450 square miles. Of this area 2,325 square miles are covered with water, giving 40,125 square miles of land surface. Its principal inland waters are the Chesapeake and Mobjack bays, Hampton Roads, and Lake Drummond. Except in the eastern section no navigable streams traverse the State, and transpori;ation is necessarily limited to railways.
STTEFACE FEATURES.
Considered with reference to its surface features — physiography — Vir- ginia is divided into three major provinces: (1) An eastern plain region usually designated the Coastal Plain or Tidewater region; (2) a central or plateau region, designated the Piedmont Plateau; and (3) a western or mountain region, designated the Appalachian Mountain province. The boundaries of these provinces are indicated on the map, forming figure 1.
As is indicated on map, figure 1, the western or Mountain province i<i divided into three well-marked physiographic belts, which extend the entire length of the province in the State from northeast to southwest. These are, named in order from east to west, (a) the Bluo Ridge, (b) the Great Valley or Valley of Virginia, and (c) the Alleghany Ridges, known alsa as the Alleghany Mountains.
The three larger well-defined topographic provinces of the State dijfifer markedly in the nature and origin of surface features, and in the age and kinds of rock. They are intimately related to the geologic
OBNERAL OEOLOOy 07 TIBQINIA. 3
stnicttire and heoce have an important bearing apon the mineral reeonrces of the State. These are therefore considered in order below.
THE COABTAX PUXH fKOVIHCE. The Virginia Coastal Plain province, the moat easterly of the three larger physiographic provinces and comprising approximately one-fourUi of the total area of the State> is separated from the higher-lying Piedmont Plateau province on the west and the deep Atlantic Ocean basin on the east. The boundary of the Coastal Plain to the eastward is marked by the steep slope of the continental shelf which lies from 30 to 50 miles east of the present shore line. The western limit of the Coastal Plain is defined by the belt of metamorphic crystalline rocks known as the Piedmont Plateau province. Figure 2 shows ilie relations of the Coastal Plain :<cdim(?ntB along its western margin to the Piedmont crystalline rocks. The Virginia
Fig. 2. — Diagraminatic section illustrating the relatioaahip between the Pied- mont Plateau and the Coastal Plain. A. Crystalline rocks of the Piedmont Plateau. I, II, III, IV, and V. Coastal Plain formations.
Coastal Plain region is more than 100 miles wide and includes approxi- mately 9,500 square miles of territory or about one-fourth the area of the State.
Because of marked geologic differences in the two provinces, most of the largest streams and many of the smaller ones, are characterized by fall" or vjpids where they itoss the western margin of the Coastal Plain, and they always show a marked decrease in the velocity of their currents from this point eastward. For this reason, the name "fall-line" has been given to this boundary, the position of which is marked on the accompany- ing map, figure 1. The position of the "fall-line," near the head of navigation and the source of water-power, has been an important factor in determining the location of many of the towns and cities of the Atlantic Coast. In Virginia, the "fall-line" passes near to or through the following important cities or towns : Washington, D. C. Fredericksburg, Richmond, Petersburg, and Fmporia. As indicated on the map, figure 1, the line
4 MINERAL RESOCBCES OF TIB6IXIA.
drawn through these places approxiinatelT separates the Coastal Plain from the Piedmont Plateau. Outliers of the Coastal Plain are frequent along the eastern margin of the Piedmont proTince. and the older cr]rstalline rocks of the Piedmont can be followed al<xig the Talleys of the larger streams for some distance into the Coastal Plain sedimcntSy where the mantle of the latter has been cut through.
The Coastal Plain region, characterized by broad, level-topped stretches of country of low relief, gradually declines in slope from tfie Piedmont Plateau border to the shore line. In the vicinity of Washington d.evations of over 400 feet are reached. Southward the western margin gradually declines in altitude to less than 200 feet in the southern portion of the State. BecauA? of these differences in elevation the topogra|^y is more diversified in the northern than in the southern portion of die State. Passing from these elevations along the '^all-line'' or western margin, the Coastal Plain declines in slope eastward to searlevel elevations along the Coastal border. Probably the average elevation of the Virginia Coastal Plain is but slightly more than 100 feet above tide.
According to Professors Clark and Hi Her. the formations comprising the Virginia Coastal Plain are given in the followinjr table:
Formations of Virymia Coaatal CKifZOlC :
Recenc
^ Talbot. ) Pteitttociiae ^ Wicomico, - Columbia group.
^ SumKirUndt ) Tertiarr.
Pi;«^«^ ' Lafayette.
Miocene
Yorittown, I Calvert, J
E^^ntj \Aquia!"*'^ ^ Pamunkey groups
Mxsozoic:
Cretaceoutf.
Lower r«taceoii2» Patapeco* 1
J I1PAHM.C *'
Lpp«r Jura««c? X Pwu.Wt. J
The deposits of the "ou^jcdj Plain consist ciiiedy of unconsolidated beds of sand, sfravel, clav. and marl, which tnav be locally isdozsted hr a •-•fmenc either ">f iron oxida or carbonate of lime. These indurated
UINBBAL RE8UUEICK8 OF VIROINIA.
'iew from RichmoDil-Manchmter bridge lonkinf; doim the JaiuM n IIoih]. Urinite boulilerg anil reeb nol entirel; coTered hj tlie high
Fig. 2.— View from R{chi during low wit ■picoously ihowi
lIliiH AND LOW WATKIt STA(;KS IS .lAMKS KlVKIt AT lUniMONI).
GENERAL GEOLOGY OP VIRGINLA. O
ledges in the vicinity of Acquia creek and, in places, southward along the western margin representing the oldest formation of the Coastal Plain series, have afforded sandstone suitable for building purposes. The beds strike in general from north to south, although some variation occurs, with a low but variable easterly dip. Although not actually horizontal, except locally, the beds generally appear so in any given section, because of this relatively low dip. Figure 2 is a diagramniatic section, which illus- trates the relations of the Coastal Plain beds to each other. In age the Ooastal Plain beds range from Lower Cretaceous to Quaternary.
The broad and deep estuary of the Chesapeake Bay, which crosses the Coastal Plain region, finds an outlet seaward between the Capes Charles and Henry. This sheet of water affords unparalleled transportation facilities, and its principal tributaries, the Potomac, Rappahannock, York, and James rivers, give access to vessels as far westward as the Piedmont border— the "fall-line."
THE PIEDHONT PLATEATT PEOVIKCE.
The Piedmont Plateau province lies between the Coastal Plain and the Appalachian Mountains. It extends from the eastern slope of the Blue Ridge eastward to the western margin of the Coastal Plain, and it widens southward (map, figure 1). Its width increases from about 40 miles in the northern portion along the Potomac river to nearly 175 miles along the Virginia-Carolina boundary. The nearly horizontal and unconsoli- dated sediments of the Coastal Plain lie across the bevelled edges of the highly crumpled crystalline rocks of the Piedmont, presenting such marked stratigraphic and lithologic contrast that the geologic boundary between the two provinces is sharply defined (figure 2). The transition on the west is less sudden and well-marked.
The Piedmont province contains a greater variety of mineral resources than that of either of the other two provinces. In general, the surface of the plateau has a gentle southeastward slope from an average altitude of 1,000 feet along the western margin to from 200 to 400 feet on the east, where the plateau rocks pass beneath the Coastal Plain sediments. The western border of the region is an irregular one, marking the change to the steeper slopes of the Blue Ridge and its outliers. The topography of the plateau is much older and more varied, and its geology more complex than of the Coastal Plain. Its topography is of a more or less smooth, broadly rolling or undulating upland, of moderate elevation into which the streams have rather deeply sunk their channels. Scattering hills and ridges — unreduced residuals — rise in some cases several hundred
MiKZKiLL ££boi:k:s Of
fem ahoipe ^le genermi le^ of ibe ixdimhc szrfiff of mt PisiBUL. Below ife uplind serf mre, deep sue narrciv ?*^^^^?^ ^^ci^ nes. la^iuI bj i3be
The drainas^ of ihr Tenon is ir liit ud tiie sugar 5T?e«in< irtiich iraTgrsp tjk Pi bumoek. .lam^s. and B<>anok^ Tiv-;r wxiboiQi the aT«u and. iriir liw ^jR^eiciiK o: their Twe w^js; o: Uie Brot Ridst. ' ana and lie henreai the mi^ rrT-r; drreethr into ihf Oh^saMtt:^ Ba^.
ar Ifsss deifr nx^v ott<^*s. and lanie ramc pcTsn^ a!^ iar aE ihe Ws'dcr of ^te IVdmonr Fiart-an, wh^^^ iheT aeamaet or ti> ^he Coastal
a irene^^ ^itsorii^rK^. o' *^ j^?*V'>£-r a: ir?^ ithv:- Tise tocss com-
Hflis^xQC ihe ^"cor art: ;h(r a-s>es: -r iS :^»ise sad. toawcHg ihe areas of Ni?wari J^ura-Trtas^ rwSKk ihe;- i.> al .r-.-s^alhiK. TS^ KHCiinse both 4«dixB«tiZKr^ arc i^rt^tNUis nia:^:^^ 5c c•v»I^* ah:*?*?!: fruHL msaniorxihiT^iu AirfT mrvuurh r^?vi!5si:n" and ^^-^-sraLrrtar-i-^iL !»: ^ajairr of ^hem bear hat sihcht -r^semjUanvV ro Tht- ->^\c^r^ r;asft«e*> T^^ iR-*^aLiauLT)itagni has UKhxc^. •^iH>\r.^s^ *.>:';*TN\r :: -S^ ^xsfc> ^^ ar-aarrr^ ibf mnieral con- >riTm*nTs altUii: -k>nn'^» ^^i* ^^^^ -.** "r»t^- '^^ -r-a^t^v i>- fnl»tw«i of which. It m5U»^ vtfcfe'v. h«?tiTs :*r*k tv re ^*-ai:N>r * '"^^ T-irJB^ bpodmc planes us niar> (V :,v ^5*\liTtK*r."5*"^ Tn*ss^«s
T*hi^ TUr;*ai. "^yv^r ^ nvauV t:r x' :i .Mc:r*'. • •' -^•h^^rs. gngiae^^ and yranm*?^ %i:h. :v :v^:«^»k *r^*a^ >\^ 5^*?!:\ c^s*"^'*- arc ':ai!*<miie- Tlii?
mjj;. A^ f»^ *N ihi^x Siin- N\'c: ^*ij»*W,. %* -S -^^a».>is; v ^^:n*_ and saWiroic rvt^'*^ To {Hi^ .»^>t. .>.:* "IV*". . r 'N \-"*»»?r:-- -^a.'^cT'v'Tt TWFTrrsr. of the
nV^iUv r> aj; .•j*>\i .* ';*'.>v >^*\>fc'^'. ^X*<^9- -^t?;??*?"-^;. — WtLr^T* €Kiendb
iVv^ th«* i-^tecfr 'f. Tvv ^.»'-r. >»j' -^ ^^v >;.•,• S'^r: **i^'^v::^^ «f "dit- P>pd- ltt«^li hTi* JlTtiHN o N.^xas -N -*;-■><■ *.^^*i3fev 0;.s.. . -;»•!•. rSs*:?ips;\
ami, »>i '«u*ii>*- .» *. i ^'i-iv v *. ^ ^ *• XN^
>»aTHiK %iI!mi' '-hiV^ h-.', " *► \ V oi >-^f->«'r :*f »ad '*•"' and. in
»>• *. »•
OSNERAL GEOLOGY OF VIRGINIA. 7
cases, steeper, sometimes almost or quite vertical. In general they strike approximately northeast and southwest. Variations, however, in both dip and strike are frequent over the region.
The age relations of the rocks of the region are largely unknown. Excepting the areas of Newark rocks, the crystalline rocks were regarded as Archean by the older geologists, and they were so mapped by Professor Rogers. More recent studies, however, based in part on fossil evidence, reveal the fact that a part of them are as late as Ordovician in age.
THE APPALACHIAN HOUHTAIK PEOVIKCaB.
The Appalachian Mountain province embraces the western portion of the State. Its eastern boundary, the southeastern slope of the Blue Ridge, forms in places not a gradual transition but an abrupt change from plateau to mountain conditions, and is reasonably well-defined. In other places the change is not so abrupt and the boundary is less well-defined. The western limits of the province are artificially drawn in the western boundary of the State. This province, like the Piedmont Plateau and Coastal Plain, extends northeast and southwest far beyond the limits of Virginia.
The topography of the Appalachian province is varied and picturesque, and on the basis of topographic types represented, three subdivisions of the province are recognized which, named from east to west, are: (1) The Blue Ridge; (2) the Great Valley; and (3) the Alleghany Ridges. The limits of these subdivisions are indicated on map, figure 1.
The Blue Ridge, which forms the eastern boundary of the Appalachian province, maintains an uneven and knobby crest entirely across the State, in a northeast-southwest direction, and has an average elevation of not less than 2,000 feet above tide-level. At Harper's Ferry the altitude of the Blue Ridge above tide is less than 1,000 feet, but southward through Virginia the ridge becomes higher and broader, and opposite Luray, Stony Man, and Hawks Bill, 4,031 and 4,066 feet respectively, are the highest summits of the Blue Ridge north of North Carolina. Plate LXV, figure 1, and plate LXXIV, figure 1, indicate the uneven, knobby crestline of the Blue Ridge at different points in Virginia.
The Blue Ridge is composed largely of pre-Cambrian rocks, represented in part, at least, by various igneous types, but sandstones and shales of Cambrian age are exposed along the western slope. It is a natural dividing line between the Paleozoic sediments comprising sandstones, limestones, and shales on the west, and the pre-Paleozoic and other rocks on the east. Figure 3, adopted from the Harper's Ferry folio of the
* - •&
«.- t ..
%.h
J* :
. ■ ■ ^1 i1»^fc— ■ ->
»«Mk
...4MN
fm mm
I'
r •
^ In
r ,l¥-
f > -
r — •• ^-
-^ ; . ^ •JT'. •
1
MMitf**<
-••h**"*"
MMm
.1/^ ... f^^^ii^nKri.ikt^kt^ Mcr^tq:
t UPS. cwno. :ir za- Jticxfe-
X ^
,^:.^ ,^.t#v-.*it; r. ^•'.♦rtii-fr; ^'nrnnii jon ^^Tut^m Iir^^iiKi. nE^inaim:
.'*/*-U**: ^ !**• ifvo- ii^4^-
"TT.
OENEBAL OEOLOOT OF VIROINIA.
The James and Roanoke rivere flow eastward through the Blue Btdge from the All^hany Ridges, while the New river heads east of the Blue Ridge in North Carolina and flows northwest in Virginia across the Blue Ridge, the Alleghany Ridges, and the Alleghany Front, into the Ohio.
The two most westerly sub-provinces, the Valley and the Alleghany Ridges, bounded by the two principal ranges, the Blue Ridge and the
10 MINERAL RESOURCES OF YIROINIA.
Allegfaany Front, on the southeast and northwest, respectively, are here treated together under the Greater Valley region. These two bounding nearly parallel ranges are separated in Virginia by a distance varying from 75 to more than 100 miles. Considered broadly, the Greater Valley region is composed of narrow valleys and linear ridges arranged in more or less complex relations. Some of the ridges, rising to considerable elevations, are narrow, of even crestlines, and of great length. Others are less persistent and have less regular crests, while others still, which make up the minor irregularities of the surface, sudi as, the hills, knobs, and lower ridges, are of lower elevations.
At Harper^s Ferry on the Potomac the Valley proper is less than 300 feet above tide, but it gradually rises southwestward until it reaches the height of 1,700 feet in southwest Virginia. It will average from 20 to 30 miles wide and is higher along the western side next to the Alleghany Ridges than on the eastern side. The Alleghany Bidges vary in average elevation from 1,000 to 3,000 feet above tide. Many of the ridges exceed 3,000 feet in height, and Elliots Knob, 20 miles west of Staunton, has an elevation of 4,473 feet.
Ordinarily the ridges are imsynmietrical, one slope being much steeper than the other. In some cases the two slopes are more nearly equal and, in cross-section, the ridge approaches that of symmetry.
The Greater Valley region is composed throughout of Paleozoic sedi- ments, which range in age from Cambrian to Carboniferous. The prin- cipal rock-types include limestone, shale, and sandstone. Four generalized sections, adopted from the Geologic folios of the U. S. etiological Survey, in the northern, central, and southwestern portions of the Greater Valley region, are shown in figures 3, 4, 5, and 6. These include formation name, columnar section, thickness in feet, character of rocks, and character of topography and soil. The principal formations of the Greater Valley region or western Virginia, especially those of the Cambrian and Ordovician systems, are described in some detail by Dr. Bassler under Cement and (cnient Materials on pages 86-167. to which the reader is referred. The distribution of the formations over the Greater Valley region are shown oil the accompanying color geologic map, and in part on the section maps, flguroK K), 17, 20, 25, and 28, and on plate XVII.
The simple horizontal arrangement of alternating hard and soft beds of the Greater Valley region which prevailed at the time of deposition, have l)een greatly complicated by folding and faulting. The present nttiiiKi<* of the beds indicates that in general they have been arched into
0EI4ESAL OBOLOOY OF VIBOINIA.
IS JCDTBLIL USH-TISCSS OT
: f:^a«
f*x-T:^x xx^TLTT^'i f>r tbr rxi3 T^ ':r^ ?^!^«^7 s^^— Tb? saher or JesB :: Tvvk? .li^ s::a1'* tzji -i3ia?C3iif irir? jr-^^gr^c jDore npidlT by air iSc 'nirSri: izd 2^rc^ ret^csGar: rxss Jik» sKZr^staDs, benee the fnr=>*r rx-k? jlt^ :r i^Ks^ril rtll^-^-siaizax VriW ib* Lmer ire ridge-
w^r±^ r: ▼::.:>. Str^iiji nr tb: ^'"^■^r-T»*g^ zl r^ rrcassMB Mac the angle iC iiT- As 4 :^e<..ilT .-^f :bf rtfoiiix ^r*:^ grbfs la&i trcsiiis of the beds
jc tie iSrwirsr Vil>T rv^tJ-^c^
■.t:
As ::2>rj.'*T;^£ :r :^sf revv-i: <r*c :f :**f ->«*3fir TaZsiST renm of T^£^2LaL ^fZTXz ,* -^rrtir',^< -T "i^ ^2*:r:L '-^*--*-'^ ^^ ^^ ^ei"--?tt an? shown.
rr^ 4:r«*. 5a.v,.:':"ii>*icerT ir^^Kv Iz. -Jjai^: rif "^isse ^be geologic
^ £:.5-?< :.' :5cc&f ;rx:^-t* itc "ir^ >r-i>,nrr i> TCTcrassiTeiT more
.•vcTUfx scc^irv^srwxri TV rii^^rsoosi Ji -rnfsif -ai^* tr^as- ar^ diacassed
■ rv?' X lie x^fT :%\* >7 :^ws«cc ."if r:^^sc ~:i:<^ j;:i*£ i^MfrLrrasg faults. Scz«£7 -v TSf '>fK*,^ir <iv^s :2:jb: x :s^ irxr'*r«*i ~jr i i»rr±iM5C-^s>aihwest izrivo,*tt :;» rvM in^^ :^*jLr 3^iv«r -rf^xrr '^x'^s i3£ :; a xxiL>:r ^f siinor «!!«:^ rSf -rrj^v^ ^xTss^ i>,. -rdiJirvv :2 ^r-V- "^Jm. i«gc tr WW?:: (1) TSf H.^ofC^'e i:r>,: 1r*,^ V,\::r x ^ '>^— . : :2\; '5't^«r X:<rT,a~^ famt;
V* '^t'^ ; >' v>; V» 1 vrr \ i S^- **:!". i:^: ^ r^* Y^xt VjlI^^ faultSw
rS* v:rix,i^ '-,»>4.x-irs ,-. .\ ^a.<^ .-. r>i: ;--^!f«rv«r Ttll*;^ r^sion in Yr;^,:t^ii jL'v vV*^ ^ N.-%v *-\ -%.v-. vcr^s ci too^> l •y^ Hi. I:?;\ 1:^5, and
t^^ ^ :V rv^\^ %*:^ ,v: :\ >»iv a^v:;;^, XTjL* la aroiua* r^itD<?c lo the ^I^^Kt^t^ .^:f ; V >X-^x
lll^ <iHWyw>w»i:FXv xsrw »r«4./ivn'-it ,. i .i.^xi >ur'^"«> ▼•nta i!X3M9ed for
OEN£EAL OEOLUOY OF TIBOINIA.
Vig. 6. — Generalized fiection for the portion of the area south of Clinch Mountain covered by the Bristol folio, U. S. Owl. Survey. (After M. R. Campbell).
14 MINERAL RESOUBCES OF YIBOINIA.
a guflScient length of time are attacked and gradually lowered in elevation, not equally but unequally, some areas more rapidly than others and some parts of the same area more rapidly than other parts. All conditions being equal, that area which has been continuously above water for the longest time has suffered the greatest effects from the atmospheric agents.
Accordingly an examination of the surface rocks over all parts of Virginia shows some effects from atmospheric action. Of the three major provinces of the State described above, the Coastal Plain, on account of its very recent geologic history, has suffered the least. The remaining two provinces, on the other hand, Piedmont Plateau and Appalachian mountains, bear striking evidence over all their parts of profound decay and erosion, which have resulted in the removal of vast quantities of rock material. Just how much of their surface has been lowered or what vertical thickness of material has been removed from these land areas and carried seaward, would probably be very difficult to say, but that it has been large cannot be doubted. Because of its greater geologic age and the vast length of time it has been a land area, the Piedmont Plateau has probably suffered the removal of the greatest thickness of material, which contributed in part to the building of the Appalachian province on the northwest, and to the Coastal Plain on the southeast.
Through this process of degeneration — weathering — which has been going on for many thousands of years, a mantle of varying thickness of decayed rock material overlies the still fresh or sound rock, except where the erosive action has not been too excessive and the slopes too steep for its accumulation. This decayed product is loose and porous or incoherent, consisting usually of clay, sand, and gravel, and on the iminediate surface forms soil. On depth it passes by imperceptible gradation into the hard and fresh unaltered rock. The thickness of this mantle of rock decay in Virginia varies from a few inches to 50, 60, and, in extreme cases, 100 feet. Over many parts of the State, so profound ' is this decay, that exposures of the hard rock are rare except along the stream courses where the mantle has been cut through by erosion.
This process of rock decay is of very great economic importance. Apart from the consideration of the great variety of soils resulting there- from, which forms perhaps Virginia's most valuable asset, workable ore- deposits have been formed by it from sparsely disseminated and non- workable mineral matter in the original rocks. This is best illustrated in the manganese deposits, in a part of the iron and zinc deposits, and in other ore-deposits described in the following pages of this volume.
GENERAL GEOLOGY OF YIBOINIA. 15
DIVEBSITT OF BESOITSCES.
There is probably no state in the Union of the same area as Virginia, that can show a greater diversity in geologic resources. This is confirmed by the actual exploitation thus far made; and it might be naturally inferred from the position which the State occupies with reference to disturbed and undisturbed areas as described above. As indicated above and from an examination of the geologic map, the State stretches from the Atlantic Coast westward nearly entirely across the Appalachian Mountain System. Within this area are found rocks ranging in geologic age from pre-Cambrian to Recent, and representing all the principal divisions of geologic time. Equally as great a variety of rock-types, both sedimentaiy and igneous, of structure which characterizes both profoundly disturbed and undisturbed rock masses, and of topography, is shown.
VALTTE OF BESOITSCES.
The total yearly value of production in mineral resources of Virginia for 1902 to 1906, inclusive, has been estimated as follows:
Year Value
1902 $10,600,000
1903 12,633,000
1904 12,606,000
1906 21,762,000
1906 30,000,000
The above figures have been compiled from the most authoritative sources, but they must be regarded only as approximate. They probably represent under- rather than over-estimates of the true total value of Virginians mineral production. The figures of production for 1906 are based on those of 1905, and when the exact value of the mineral production for 1906 becomes available it may show some variation in either direction from the estimated value given above. A very striking feature in th(^ above compilation is the enormous increase in the value of mineral pro- duction for the years 1905 and 1906 over the preceding years. In 1905 the production nearly doubled that of 1904, and for 1906 a marked increase is shown over that for 1905.
saiL^nHn .^NQ ixfMM:Bsr:2£.
Z%9%^}ZU
3iAENT JtSU ZSaaiESm ^A/r^=™nu-^^
«« mm
3EHLDDKAMI HWIMTTWriL.
.1 :ie "^tacEL. an o^ cm:r i -^jn» TZTrmcfe ttiasisaasLr jthttUl
.tut .7i\-rr jQiidrnz 3. "wisunnTia. _ .r::- trrfcT \jiu ; - jammauf • c -as-
Tat I " *f''TIt=^
■^ i'lc-ffin^-
7. it^
\ rrrtiu "^TfH
|
-«r |
rcnire |
"^tt'Jt»<MWr |
SA.«r |
.1 .cmiuu |
r^uB. |
|
•fift |
i: : i«> |
■ -L'.V |
-!'•**..»- |
--W^.k!-* |
< -m^^a» |
|
cf)f |
.. *j . |
.,X' |
"*.;•«■• |
?<.' |
*.:tW4l.W' |
|
.IJ^ |
. <!LC4*' |
-.:V.V |
■>y!..-5»i |
:54,. : J |
>T946r'»' |
|
rtft |
. *...,;.■* |
:i.K 1^ |
•>:#.::»*7 |
mk<m' |
|
|
.lu |
■■. " ^^ |
5.: 22 |
VJt.^'fc? |
«-L>«> |
■.««r.4««. |
|
,l:n |
•ii ::.;<» |
:.CvW |
. VJ, .' -i |
» :."W |
-I.I.^M' |
BDtLDlNG AND ORNAUBNTAL STONES. 19
MSOEIPTIOV OT SBAXin ABXAI.
The ?etenbiiig Area.
The Petersburg granite aroA inclndee the extreme northeast part of Dinwiddle county acd the contigoons Boathe&st comer
ng. 7. — Map showing locitioo of sraoiM quairiea in the Pelenburgam.
Baaed on the Bermada Hundrad and Petcnbarg lopcwraphic si
Sait, ( inch eqnaU 1 mile, approzinutel;. Contoar it
iDdicRl«d b7 hmfj doU.
. 0«oI. Borrcf. iterral, 20 feet.
of Chesterfield. Granite quarriee are opened and operated about 2 miles west of the city of Petersburg and at a similar distance north of ihe city. The principal qnarriea, shown on the map, figure 7, include the Lasetter and the Petersburg Granite Company's on the west side of Peters- burg, and the Cook quarry on the north side of the city.
The rock from these quarries is a closely similar biotite granite, of
t^ jCIS£Ltl iUi^jrjiiriJi -07 Tnn^m
Tfti»r> ;abiv.uCi» : "uU^- ?'>?MS3ii'u^ £Rft: 't lisM- BnmrmMi'^ apesft: and (3) fU&A f^^sCivnv'Lftiv-^-^i: «.*'*«. Tijfi }^23Li!spL 'Vanmtxet fxmpnmf time iiiw
?.:Mwt *(:i^^ «j% ift-i>?%. g,t iij'.f 4i:?»sifc»- tsiMf aaun^ viaidit aae thow of t^rUiz, ynajfjt Z^vsr^. F.u^jiTiTa a&d Asoiien: nwinlifft TSiae ore 'C<HiuipKii«.>< X£;jju'/f 4iff«tt fjLjfi}- 'MnQHSKr of isiie jAck -of dcivkniiDaii in Aem. hfiUttU: '^:\^n ji 'Xiii*!? PkibauoDS coinuitt tmz h imt hoc wi bfcn qamied.
1 M • I J
III U^, KKAT. .''tjx.^mIiu': «ft««. ^.W Vc^gmia gmusci ne ndzmrs of tM4iifi^e. ''■'jtifanz. aii^c ViK/l:^, vitL nFoaLj mort or kfli of the vfaiie miei, MiiiMfV*-t;ri^. If.'yrLi.r^^n/O^ » «r ianponass ooiMtitiiaii in o put of die ^Mi';ru^ ;£. r<rj^ f ftjji Ci!iij<r± ilpm, near WafihinglUBL in Faiifix eoonty. fj^t^i^, A 4 yns^ri'/iL ^^^XifelriiKTZit in the Tmrierr of gramte knovn as tuutk'M:. yyti'^r. ^ }</ti£^c Mar Liaraj in Fife and Hadiann oonntia, and :uwr l^if/viryici^ ,:: Or%v«<a ooiuxtj. In addition to the principal feUipary y^iv«Jitf»»^ w^-ji".-?^^:,:!^ ^SA piagaociase occur in vidtij rariafale amonnta.
ti^oM^sk -'>.i* A^/MraiiX mentioned, tbere occur apatite, liroon, wf^beat^
Jkr44in,-< vi .»v v^i ar^-: r.rv/iiir*r ibr** t^pes of granite occur in
/,4»«fi t *-*r..7'.<r. •. jtr ;rr«Lr!:V«: ^2> porphvritic granites; and (3) ^4^\^'vn.^^ v 'v 4 /•/ /-»;."■•■■*• jfrarjit^-gneisfies. Based on mineral com- yy^i- *yj\ ifi t*:* .t ^v,.vw.f.ir TYpes of Virginia granite: (1) Biotite ^laj.u. wi.'tv,. r •..:•. a ::.x//r,'.y of the granites of the State may be ^,Mi..y.v ;: 4 •.!«', V f.t /;*.'..>; (?,) hornblende-biotite granite ; and (4)
♦ I,* ,".u .*,', '. ,'•» »/.;,.•.. /yf liichmondj Petersburg, and Fredericks- lit* > ... ' ^« it.vp V. y/***;.?'., *?^/>norrucally, in the State, and they best i!.i4*...i.. -y*., v" .\'.,.'x '/r^fi'iU:. I have elsewhere discussed these
... '.• .:•*' .' y -r* M; The Hic'hmond-Fredericksbnrg light
^••v ' -'^ 1' *^.' •'.v..^ >^•^/:i«^•i'kllblJ^g dark blue-gray; and (3) the i '...-■., .• /i« . ':-, •r,<-i'rf. arrj added the Falls Church daric , .- . • .1 . .-'. • A ;-..t, */.'j i\ti: yellowish green and pink epidote
'/•</.. *-(•« found but not quarried in other parts • v'.;^ v. './.a- *tr the other of the above t3rpe8.
I » ,\
t ■ ■ ) •«
BUILDING AND ORNAIEBNTAL SIONBB.
The Petenbn^ Amu
Tbe PeterebiiTg granite area includes the extreme northeaat part of Dinwiddie county and the ctmtignonB southeast comer
Fig. 7. — Map shoving location of Kimoiu qnarriw ia the PeieraburgareiL. Quarriea indicated b^ hw 8«Md on the Benunda Hundred and Petenborg topc«raphic iheets, U. S. Q«ol. Barre^. Scale, 9 inch aqnals 1 mile, approzimatel;. Contoor interral, 20 feet.
of Cheeterfield. Granite quarries are opened and operated about 2 miles west of the city of Petersburg and at a similar distance north of the city. The principal quarries, shown on the map, figure 7, include the Lassiter and the Petersburg Granite Company's on the west side of I'etera- burg, aud the Cook quarry on the north side of the city.
The rock from these quarries is a closely similar biotite granite, of
IS XDOKJIL KB50C1BCSS OF TIMESXlA,
WBtb-^tmA direction, abxig libe euKni border of tiie PiediiMHit regiMi. Tber iaehade (1^ ^ INefersbin;^ ofoa: i^t the RirhTTinnH am; and (3) die FTedencksbuT^ aret. The pnncpil conmitt campaang these areas are Dinwiddie* Cbe^Te^fie}d, HenrxKx and S^MCXs^^^raaia. In addition to x^Mse diere are several minor aiiea^. ciiief among vbich are tiiofie of Fur&x, Prince Bdwai>l FhcTuma. and Aic^xm onwnim These are df5^pia»d mines' anias cSiii^T beicaiae of liie jack ci deTri<«zanent in them. Giaxd'^ ^>cirxi7S in Mbn- Piedmom ccwnixs )«xn ii baf not m been quarried.
In liie mof^ imionani aT«is. ib^ Vsrixoa iiraniies ai« mixtures of feUkmr. risanx. anc r^kciie. ^rrdi ns^iLaUr mfio^ osr Iok of id« viaite mica, iiniscvvritie^ H<»mb]«ni3e is an izD|iOiruni ooatfctneni in a part of die ^ncutes in liie Falk C2iii:^ a3>ai» near Wadiingnm. in Fairfax eoonty. EuidfOie is a phncdpt: c(m«^Taent in dke Taj36nr of cracite knovn as imiliiK^ K^ikih i< foixinc neu- licnT in Fige ana HafHwm csontieEv and near TNorrdaj^' tc Grftx^sion oosnrr. In additkai tx^ Tb^ ptrrndpal feUipor, orduiRias^ mkr^riline an3 plapoclasie wicker in widecr TariaUe amoenta.
Besdes ^ mineral meniionfid. d)«?e dcmu aMiai«^ zimvu qihene, maTMcrie^ ani M^i^ir Ac^oasi^mal iOm^
«n TtrniTx aT)£ ^rxK^xi* iJri^w- t^7«^ cd rrKnir* «xtct in Vii^ginia : il ' VaRsri%. <«wi«?ftT;T4laT rrKnin^: <$' TiwrTiiiyriTir paniies: and (3> schisa^ij^r «- f^hiT<»J: frr^rr'rs' — ^rfcTiir^riKMSsies^ Ra»ftc on mincn} com- jMifdnmL "we >iavc- tljf fi^k-ii'inr i:i?« «f TiT^nia p^iniTe: <1) Biodte gTKX£it(-^ UTiBer v^->ch a Tr>^i*>r:;7 ^f rbf rn-XiiTi^ nf the- Sjait* max be rri«np<^: it^ Tr.TKw^riTf rrfcTiW; J^ ■ >)nnihjni»»'if-Mf«437f rraniw^; and i4t
Th^ |!!Tiai:i«. iX rihr Tv.rri} cd T^K->i7nrtn«v TfO/c^jaoiTx:, anc F^wierkis- btR^ a:^' tJjc tijar: mwrtanr^ <ip«DOTni«aLh. in the Sraifc. anfl dier besat
dK^ fh:?<V' fWi)f''trmc niv^ : . l Yh( T^u'hTnftnc-'F'yeidcnriaftiiny light i ii^ 'Att ^kiAatifmi^TTt^Sitiru^kAnrr^ d&ri hm^rrraT : and i^\ the VtoBffmisii<a^ "h^^R ^^riiy T^* r>«v art a/»n<v: rbf Falis OhnTT^j dark
t(||it» lnMf«% ^ :tma)rr»i. tvr^bniti^ frrnnr. ha: da: tiiiarrmc in rosier jmris
BUILDINO AND OBNAKBKTAL BIONXB. 19
The Fetenbo^ Ana.
The Fetenborg granite aree includee the extreme northeast part of Dinwiddie count; and the contiguous aontheaet comer
'H- '- — Hap (bowing location of ftnniu qiiarriea in the Petcnburg am. Quarries indicated bj hMTj doti. Baaed on the Bermoda Hundred and Petenbarg topuraphic sheets, D. S. Oeol. Sane;. Scale, I Inch eqaaU 1 mile, apprazimatelj. Contour itit«r*al, 20 feet.
of Cheeterfield. Granite quarriee are opened and operated about 2 miles weet of the city of Petersburg and at a similar distance north of the city. The principal quarries, shown on the map, figure 7, include the Lassiter and the Petersburg Granite Company's on the west side of Peters- burg, and the Cook quarry on the north side of the city.
The rock from these quarries is a closely similar biotite granite, of
M lOXIBLAL SSSOrXCSS OF TISGIXIA.
SM&X2C i«xnii«. iz>c cTiT oQtlisr. 1^ ^Txxme fnxm &e Cook qoMrrj eon-
tftizts Jess znSci (bxKiiTr) ihun tbsx from the ires sde {jiairrieB. and is •MCuriiii^jT liiit^' in owot. Tbe suom: from lirtse q-narraes i» of ex- <xilieDi nftlirr 4z»d is m^ f cr all purposes madf of rraadseL It ia of bcBDrt^KDeMr^ t-r^::^- ircod Tiermanean ooJor. asd ramajns bo hannful zniT^ffTfil The ;:iii:-T*l£Des a:^ iriatiiT sparied. readilT adnulUpg of tbe
Onitt iruam, — Tii* cTiarrr i? iC»aa.T£»d aibain 5 mikt nordi of Peters- imn:, iiLDft5:£T<CT an tie* vest sot of ih*- Seai»oard Air line RaSvar, and ▼tiiiii .^'iH'' fefc fu the CTOfisimr of thnf Toad 1»t libe Bdt Lum*. Some ^sxa» ir«j; cT;£rr}ei as afcr.y a? InoT, :.ii: frffifanatje qTiaTrnii|r vas not r»fycx XI3TU iJ^T, riax* II. irnrf 1, if a -new of iliif cfMcny.
Thi sr^iiDi -if aiiL:rL:.h acifcTced to the ixses madt- of iL iriiScii are for toiiiiM T'urposes, ir sirert work of all farm& tnrfhaifiTg llock^ and niTti>:ii£: SlDi CTz&ht<. st-cme: and in 'valL lihdi^EL. and c^cl^en voik in die TOuA and dr^f^xtd srax&. A rmsber is operated at the qiiaiTT for vorldng HT' tlx- OTarrr-irasj*^ naainjj foe oanoreK pnrpoaes. The laitpe^ siae wa^ is made inTf TiiT3ir >uix*fc&. tihe «eoond into miibie piling, and lie balance is PTDidM^d foe concTfW vorn. Tne rraniie froxL this qnanr is s^pjKd ^r the prinrf.pal points*, inolndinf X^ir York and as far wesi as CiBcannad. ftiwbrjilh no shirnnffnT* m^ made <»oinii of Tirrinia
• * ^
Tkf Lasfti^-fT audffrritai. — l%es^ cmarne^ are looarad Atna 1-5 mikB ves: of Pet^^r.xrx:, iirimodia:<?!!T or. the oar line of the Ti-cmia Fasenfcr and Pffwfc iTomTifinT^ and vivihin a onarrer of a mile of die OiaihfiiiJ Air I/.ne l^iVftT . T^.r» or f :itT openings arf made oJoae T.opsdier nAida wwe f.TSi worked. m:*re t>iI.i. ^C< ^'ca-ts aco. Tnirinr th£ janmner of ISK^ S of xh£ maxdiurs iw-rr h&n^ opfirfiw. >t spparaTe partifia. ^Rie Lfljwt ow of l5M»e ^fp» operate": >'X C. M. V^lsh of Par^cshnri:. cxdhaOThr fcr m*!i>». B«v^ **0 fM5 and morr in itmpn. are ocmsOKDtlT teii^ frmr. the Vals>. opcLinr. Thi rran:re is of iitfflimi irrar ocUn, Ae Md- fiT«rs of v>.i;*> >tt.T( t dexi.w. 7>.nkish oasc^ Ii ip^i^ inJD jmBer iht httUimfT ttnd is wrs^oerrnritrje of i; >iurV. t^olish. li is snsnai^^ aoal in Ifce mmnrmtnn M)d hx^.^rliTir trade^ T»r*nc^^Tialh in the farmsr. Tie fBsrrr watcM is iirrikftL t.t and imod for m>ihie. As uumamsaBkl Mbmjt 13tm fTUtil^i' is mfcTknred ovor * 1*^rtf tcr^iT^orr, ahipmams ^im^ made ais far
T^Kr PfTt-p^hfT'c vhanUt Coffivofn. f wa^-^S^^. — The OQKnvff «ff diia ^amtipaEtT ■inolnAf rvf. lar^ opf^jTurs fipvara. htmfired j«rfls ^qaffL, locattd •toii»edM:T^f> M/»7ig thf -.UT :.m o: zhi Pcwsrsbcrx: PasKai|f8r aoad IVa«r
MIN&EAL RSBOURCE:^ OP VlUiil
GRAKITE QUARRIES IN PKTERSBUKG AND RICHMOND, VIRGINIA. ARKAS.
BUILDING AND OBNAMENTAL 8T0NB8. 21
Company, 2 miles west of Petersburg and a half mile west of the Lassiter quarries. The 2 openings are designated as Quarry No. 1, known as the Asylum quarry, and Quarry No. 2, known aa the Dibble quarry. The openings are large and are made in flat surface exposures of the granite. About 5 feet of stripping, comprising sand emd gravel of the Coastal Plain and decayed granite, must be removed before the quarrying of fresh granite can be carried on. ^., . ^
During the summer of 1906, Quarry^Np. 1 was being operated under lease by Baltimore parties, and the stone was being used almost exclusive- ly for building purposes in Petersburg. Some of it is used for coping iv cemetery work. Quarry No. 2 has not been operated for four or more years. A large quantity of stone has been quarried and used for the various purposes made of granite. The joint-planes are widely spaced and dimension stone of almost any size can be readily obtained.
The Petersburg Passenger and Power Company's quarry. — ^During the snnmcier of 1905, the Petersburg Passenger and Power Company was operating a quarry at the dam across the Appomattox river, 7 miles west of Petersburg.
The Biohmond Area.
The Richmond granite area, covering parts of Chesterfield and Henrico counties, in the immediate vicinity of the cities of Richmond and Man- chester, is the largest producing area in the State. The quarrying of granite in this area dates back to the early part of the last century, and a large number of quarries have been worked from time to time. These are opened largely in the granite bluflEs along the James river, extending in a general westerly direction from the city of Richmond for a distance of more than 5 miles. To a smaller extent quarries have been opened to the north and south of Richmond in the low granite ledges exposed along smaller streams and in the flat surface exposures on the inter-stream areas. Many of the quarries are very extensive openings, and have been worked to a depth of nearly 200 feet, from which an enormous quantity of excellent stone has been obtained. In some of the larger quarries, the depth reached in quarrying is below that of the river level. The quarries opened are well located with reference to transportation facilities, and admit of easy working.
The location of this granite area at the head of navigation in the James river affords cheap transportation of the stone by water north and south.
<9<«
xixnuL ssEorsi:n2& or tis^ixul.
ITOCL ics? :o r::^ win grai::ilir 'jz t^xtz^^ *z.-i frrci iark :o light gray in vxv:r. Xear Miilo-thian. lo ni'f* ttsc cf E:±=i':-L *&£ extending for m ronrtfc-^soc^h vi:>:arv.>f oi ix-^: f^> niLcs. i* & ]>r4:r:i5il coarse, porphrritic, ::cci:if j:t:iz.::c\ vh:v']i his rx j^ :e^ crArrt-^c :c %zj extent.
/oi:r:iruc :> :i>uil> w^H i--TTl:T^ in ib* iTi^:e5 'r:n the planes jTik:^ r^:^.c:;^ci:*; far itilt: :^ iinr: :f i!zi«»": inj 5^ scone being c^4rr:«c. r=vTr.i:::e T^ir^ .^7 iii-^s. .^-ar^e :rr5calIisi::-X5 of quartz and fi£^ispir. in* r.o.: jv^c:---:.- -:ir::'rr:-> :^' .'4:2?e v-ise iz. ^rzarrrinz.
T^»v ir»i^ :f tI--- rnziiic xcir jzj£ ir« ::Ltrr>r«i. m? a £i!ss^grained cjLri ':I'-:^-z^7 rxk ■•x:c-->:Ttl7 -i^tc i* r::z.:izjc-': >::•:■£. ±«r :cber a coarse
' ^* N^^-'
i.7»- c^*\:' -i ^.vi I*- -^: >;-r;f»i frf r^:. '.-.^^ T-xTTC^sfs^ Boch are
.T •^■ss>* -:- K?f y ,;■ -. ^ x.^'*>* *•; ^ -.'.•■■i.*^ r^t*i;"j:nj5 SfCv^sen the ■T'* ^•^■' .-* <-* ■wi'ti"'- ■• ^- \ *'■-"% .-^T* ; ..ir^ vf^ :t 3^i;*h3icc<c. The
y-i^-'-rrrt' ;-i ' .>i f-»; -. -.-v ^■* <; •• :r u : i.>%j*fs .*: ▼^rck is. which
V :\''<L3-:r7 aad the
|
•-•. .t • |
'*■ |
"■■'>. |
; * s; -*• |
..., m |
-s '". |
■ ■' |
-• |
• |
|
• TV • •»-. |
■ 1 ■ |
• • |
■ ' ■% |
■ |
1 |
|||
|
s « •■ "*• 1 ■ |
\ • |
\* |
« |
^ |
' :->.' . |
^ |
. '4 |
|
|
.-i • • |
HINBUL RB8017BCES O]
"■P ot the Ridnnond gr«i ■liMt, U. S. GeoL Sun BJcbmosd sheet, 20 f
22
MINERAL RBSOUBOKS OF TIBOINIA.
The quarried granites are feldspar-Kjuartz-biotite rockB, which tbtj from fine to medium granular in texture, and from dark to light gray in color. Near Midlothian, 13 miles west of Richmond, and extending for a north-south distance of about 20 miles, ie a beautiful coarse, porphyritic, biotite granite, which has not yet been quarried to any extent.
Jointing is usually well developed in the granites but the planes are spaced sufficiently far apart to admit of almost any size stone being qnarried. Pegmatite veins or dikes, coarse crystallizations of quartz and feldspar, are not sufficiently numerous to cause waste in quarrying.
Two grades of the granite occur and are quarried, one a fine-grained dark blue-gray rock extensively used as monument stock, the other a coarae
and lighter gray rock admirably suited for building purposes. Both are homogeneous even-granular granites, possessing good working qualities. The fine-grained dark blue-gray granite is susceptible of high and per- manent polish and is a superior nionunientaJ stone, possessing as it does that strong contrast in color between the polished and unpolished rough or dressed surface. Figure 8 shows the structural relations between the two granites as exposed in the \ctherwood quarry west of Richmond. The Kicliniond granites are thoroughly suited for all classes of work in which granite is used.
Prohiibly the most elaborate giiiniti; structuie in the country and the most important building yet constructetl of the Virginia granites is tha State, War, and Navy building in Washington, built of the Richmond jrranite.
KtNIUL BBSOUBCBB 01
^Pot tbe Bichmond a
/ /;;^^ 7
PUBLIC UBU^R^
AND
TlLOfe*'
BUILDING AND ORNAMENTAL STONES.
28
The following is a list of the principal quarries in the Richmond area :
Name. Belle Isle Quarry,
Donald Quarry,
Granite Development Company's Quarry,
Hawkins Quarry, Krim Quarries, McCloy Quarry, McGranigan Quarry,
McGowan Quarry, Mcintosh Quarries, Middendorf Quarries, Netherwood Quarries,
Old Dominion Granite Company's Quarries (Middendorf),
Philadelphia Quarries,
Richmond Granite Company's Quarries,
Smith Quarry,
Tidewater Quarry Company's Quarry,
Westham Quarries,
Winston and Company's Quarry,
Wray Quarry,
Location.
Belle Island, above Richmond — ^Manches- ter bridge.
Half mile £. of Belt Line Railway, & side of James river.
One-eighth mile E. of Granite, S. side of Southern Railway.
North side of So. Railway at Granite.
Three-eighths mile S. W. of Granite.
One-quarter mile W. of new reservoir.
One-eighth mile VV. Belt Line Railway, on James river.
Two miles S. of Manchester.
Half mile S. W. of Granite.
One-quarter mile S. W. of Granite.
Two miles W. of Richmond, on S. side of James river.
One-fourth mile N. 30'' E. of Granite.
East end of Settling Basin, on N. side of
James river. 4.5 miles N. of Richmond, near R. F.
& P. Railway. Canal locks W. of Richmond, N. side of
James river. Two- mil^ S. E. of Manchester, on James
river. 4 miles \V. of City Hall in Richmond, on
' S. side of James river. North side of James river, at Settling
Basin. Three miles W. of Richmond, on S. side
of James river.
Of these, the following quarries were being operated during 1905 and 1906 : McCloy, McOowan, Mcintosh, Middendorf, Netherwood, Richmond Qranite Company, Winston and Company, and Wray. Some of the others have not been operated for some time, and in part they include the most extensive openings in the area. This is particularly true of the Westham quarries out of which stone the War, State, and Navy building in Wash- ington was constructed, and the quarries of the Old Dominion Granite Company, known at present as the Middendorf quarries. Only those quarries which are mentioned above as operating during 1905 and 1906 will be described. The other quarries are equally as impori^ant and are capable of producing unlimited quantity of excellent stone, but many of the openings were partially or entirely filled with water at the time of iny examination and were not entirely open to study. Map, plate III, shows the distribution and location of granite quarries in the Richmond area.
I ; I
i
i
J
■■ I
V
'i
I-
.■I
I. i'
I
1 1 ■ 1 . I
.:"
24 MINERAL RESOURCES OF VIROINIA.
McCloy quarry, — The McCloy quarry is opened in a flat surface ex- posure of granite, located about 300 yards from the James river branch of the Richmond, Fredericksburg, and Potomac railroad, and about a quarter of a mile west of the new reservoir. The quarry opening includes about 1 acre of ground. At several places about the edges of the opening the granite is decayed to a depth of 3 or 4 feet, which must be stripped before fresh stone can be obtained. The rock is cut by several well-defined sets of joints which vary in direction, from N. 6® to 86** W. and N. 10* to 76** E., and in dip from vertical to 66** N". W. The rock is a very fine- ' ; grained and even-textured, dark blue biotite granite, admirably suited for
monumental stock, The principal uses made of it are for monuments and building, and for street purposes as blocks and curbing. The quany waste is crushed and utilized for street concrete or cement work. It is marketed in a number of states, including Virginia.
McOowan quarry. — This quarry has been worked for about 10 years exclusively for monumental stone. It is located 2 miles south of Man- chester, about 300 yards east of the Petersburg turnpike, and 600 feet west of the Seaboard Air Line Eailway, with which the quarry is connected by a spur track for shipping. The opening, which is a large one, is made in a flat surface exposure of granite, and the average depth of stripping; including soil and partially decayed granite, necessary to the quarrying of fresh stone, is about 5 feet. It is a fine-grained dark blue-gray biotite granite, of uniform texture and color, and a most desirable monumental stone. The quarry waste is utilized largely for paving purposes. It has an extensive sale in the monument trade in many states, including Virginia. Views of this quarry are shown in plates IV, V, and VI.
'Mcintosh quarry, — Tho Mcintosh quarry, formerly known as 'Mat- lock,** is probably the most extensive working granite quarry in the State. It is located near Granite, a station on the Southern Eailway, 6 miles west of Richmond. A spur track for shipping connects the quarry with the Southern Railway at Granite. It has been operated for about 15 years. About 2 acres have been stripped from the fiat ledge exposure to a depth of 37 feet. The fresh rock is exposed at the surface and no stripping of decayed material is necessary. All work is done by compressed air machinery. The stone is of excellent quality and is used for all classes of building and monumental work, and for all purposes for which granite is handled, except in the form of crushed stone. The principal directions of jointing are N. 10** W. and N. 65° E. All the approaches, steps, etc., to the new Capitol building in Richmond are from the granite of this quarry. It has an extensive market in and out of Virginia.
HINBBAL BESOL'ItCBS OF ViROINtA.
Fig. 2. — Granite qunrry near Rirhmond, showing jointing na in Kig. 1. CRANITK QIAKBIES IN THK IMCHNiOSn. VIKCIN'IA, ARKA,
1i!
I'
^iii
1:1
BUILDINQ AND ORNAMENTAL STONES. 25
Middendorf quarry. — The Middendorf quarry is located on the Belt Line Bailway west of Manchester, and 760 feet north of the crossing of the Petersburg turnpike by the above railroad. The rock is a banded biotite granite-gneiss, penetrated by many pegmatite dikes and veins which vary in width from a fraction of an inch to several feet. Directions of jointing are N. 65** E. and N. 45° W. Strike of the gneissic structure or banding is N. 65** E. Several acres of the gneiss have been stripped to a depth of about 25 feet. The stone is used for ballast and paving blocks, largely the former.
Netherwood qucurry, — This is one of the most extensive quarries in the Bichmond area, and it is reported as having been worked as early as 65 years ago, although operated under the present management for about 8 years. The quarry opening is made in the high granite bluflf on the south side of James river and immediately on the Southern Bailway, about 2.5 miles southwest of Bichmond. The greatest depth reached in quarrying is 65 feet of fresh granite covered by about 2 feet of red clay on top. The ledges of granite average from 20 Ao 22 feet in thickness. Two grades of granite are produced, a medium coarse light gray for general building purposes, and a fine-grained dark blue-gray for monumental purposes. Neither joints nor pegmatites are too closely spaced nor too numerous to prevent the quarrying of dimension stone — ^any size blocks of both the gray and the blue stone being readily obtained. It has an extensive market in and out of the State; and is used for general constructional and monumental purposes, curbing and blocks for paving, and crushed stone for all purposes made of granite. Its principal use, however, is for building and city (street) work, which comprises mostly the light gray coarse granite.
The Richmond Granite Company's quarries. — The quarries of this com- pany, owned and operated by Copeland and Brown, are located 4.5 miles north of Bichmond, near and on the east side of the Bichmond, Fredericks- burg, and Potomac Bailway. It was first operated about 15 years ago. The dimensions of the principal opening are 500x100 feet and 50 feet deep. A spur track is operated between the opening and the Bichmond, Fredericksburg, and Potomac Bailway. Two principal sets of joints, spaced at distances of 2, 6, 8, and more feet apart, intersect the granite, with directions varying from N. 10° to 70** W. and N. 30** to 35** E. These dip from the vertical to 35** S. E. The rock is not sheeted but is perfectly massive, and is an excellent grade of biotite granite. Pegmatite dikes or veins varying in width up to 8 feet occur, but are not numerous
26 MINERAL RESOURCES OF VIROINIA.
and do not interfere with the quarrying of dimension stone. A crusher is operated at the quarry for working up the quarry waste for the various uses made of crushed stone. The principal uses made of the granite are for street work in the form of blocks and curbing, for building and monu- ments^ and for crushed stone in its various forms.
Winston and Company's quarry. — This quarry, formerly known as the Mitchell and Copeland quarry, under whose management it was first opened and worked for 12 years, many years ago, is located west of Rich- mond at the city settling basin, just completed. The quarry is opened in the granite bluff on the north side of James river, and is of large dimen- sions. The present operators, Winston and Company, contractors for the construction of the settling basin, began working the quarry about 3 years ago to supply crushed stone (concrete) and rip-rap for building the settling basin. The stone was quarried by blasting. The principal joints strike N. 6** W. and N. 30° to 70** E. Pegmatites are not numerous. The granite is sheeted to the entire depth of working, the sheets being thickest at the bottom and thinnest at the top.
Wray quarry. — This quarr}-, operated since 1895 for monumental stock exclusively, is opened in the high granite bluffs on the south side of the James river and inunediately on the Southern Railway, about 3 miles southwest of Richmond. The stone is of the excellent dark blue-gray biotite granite, of uniform color and texture, and is admirably suited for the use made of it. The joint-planes are widely spaced, admitting of almost any size stone being quarried. The working face in 1905 had a depth of about 75 feet. Occasional pegmatites not exceeding 3 inches in width occur in the granite but give no trouble in quarrying. Its sale is practically limited to the principal cities in the State for monumental stock.
The Fredericksburg Area.
The Fredericksburg area includes the region to the west and north of the city, in Spottsylvania county, in which granite quarries have been opened. The granite exposed along the Rappahannock river north of Fredericksburg extends into Stafford county, but no quarries have yet been opened in that county.
Two types of granite have been quarried in the Fredericksburg area, one a very light gray, medium-textured, muscovite granite, the other a dark blue-gray, very fine-textured, biotite granite. In texture and composition, the latter is identical with the fine-grained dark blue-gray granite quarried in the Richmond area and so extensively used for monument stock. The
BUILDINQ Ain> ORNAKBNTAX 8T0MB8.
37
Fredericksburg granite is a shade darker in color tb&ii the Bichmond stone and it is a superb monumeiital stone for which it has a wide usage. Map, £gure 9, shows the location of the qnarries in thie area.
Fig. 9. — Hip showing location of granile qouriei in the Fredaricksbarg Qa«rri«t iodicated hj beSTj dots. Basad on ihe Fredericksburg topographic iheet, U. S. Ueol. 8arvej, Scale, | inch eqaali 1 mile, approiimatAly. Contour inMrval, 60 feet.
Hazel Run light gray granite. — A very light gray muscovite granite of medium texture is exposed along Hazel Run,. a tributary of the Rappn- hannock river, and about 1 mile west of Fredericksburg. It somewhat resembles the Stone Mountain light gray muscovite granite 16 miles east of Atlanta, Georgia, which is so extensively used for general constructional purposes. In the spring of 1879 an opening was made in the flat ledge
I
29^ MINERAL RESOURCES OF YIRGIKIA.
immediately on the south side of Hazel Run, about 1 mile west of Fred- ericksburg, and enough stone quarried to build the Presbyterian Memorial Chapel in Fredericksburg. No stone has been quarried since. The joint- planes are widely spaced, two sets of which strike N. 75** W. and N.-S.
Cartwright and Davis quarries. — The quarries of Cari^nright and Davis, located along the Rappahannock river 3 miles north of Fredericksburg, are the only ones operating at present in Spottsylvania county. The quarries comprise 8 openings, 6 of which are made in the granite blufib along the south side of the Rappahannock river, for a distance of neariy half a mile. The granite, an excellent grade of monumental stone, is a massive uniform dark blue-gray colored and fine-textured rock. It is intruded into an irregular banded gneiss of similar mineral composition. Strike of gneissic banding or schistosity is N". 26** to 40° E. The granite is cut by several sets of joints so spaced as to admit of any size blocks of stone being quarried. The principal joint-planes strike N.-S. with a dip of 40° E. ; N. 60° to 80° E., dipping 10° to 30°, and N. 20° to 80° W. In places, pegmatites are abundantly developed in the granite, which occa- sion at times considerable waste in quarrying.
No dimension stone is sold in the rough but it is all worked up at the "yards** located in the northern limits of Fredericksburg, and is used ex- clusively in the monument trade. The yards are commodious and well equipped with the necessary modern machinery for all grades of polish and dress work. The stone is conveyed from the quarries to the yards, a dis- tance of 3 miles, by canal. A crusher is operated at the yards for sizing the waste which is utilized for local purposes.
The monuments made from this granite have an extensive market in and out of the State.
The Fairfax County Area.
Granite has been quarried in Fairfax coimty at the following localities : South of Falls Church and west of Annandale. The quarried rock is similar in the two localities and is taken from less schistose portions of the granite mass. It is homogeneous, of even texture and good color. It is not materially effected by schistosity, and works out readily in stones of moderate, size. Some of the beds in the Falls Church area are colored by pink feldspar. Many portions of the granite-gneiss furnish good material for foundations and similar rough work. This stone is schistose and con- sequently not obtained in large masses. It is ea^ to quarry and is strong and durable. Many portions contain pyrite, which unfits it for ornamental use. Many of the more massive beds of mica-gneiss are suitable for
BUILDINQ AND ORNAHSNTAL STONES. 29
bxdlding and resemble the more schistose portions of the granite mass. They are used locally in the construction of dams and foundations. From the thinner and more micaceous beds flagstone can readily be obtained.
The granite quarried in the Fairfax county area has been used entirely for local purposes.
Falls Church area. — The granites in the vicinity of Falls Church are of two varieties. One is a medium- to fine-grained crystalline rock and is a biotite granite carrying a variable quantity of muscovite. The other, a light and dark speckled rock, is a fraction more coarsely crystalline and is a hom- blende-biotite granite. It is the only representative of a hornblende granite yet found in the State and it is closely associated with diorite masses on the one hand and with foliated mica-granites on the other.
The Trip quarry, located about 1 mile south of Falls Church, was first opened about 1872, and has supplied considerable stone for local purposes, principally for foundations and buildings. The granite is massive, of medium texture and of variable light gray color, depending upon the amount of mica present. Several sets of joints are developed which usually cut the granite at close intervals and limit the size stone that can be quarried. The directions of these joints vary from N. 10** to 80** E., and N. 10^ to 80** W.
The Presbyterian and Catholic churches at Falls Church were built of the granite in the rough from this quarry.
AnnandaJe area. — The Hoffman and Miller quarry, located about 2 miles west of Annandale, directly on the west side of Accotink creek, has not been operated for 12 or 13 years. The opening is made in a boulder ledge exposure on the above stream and at water level. A stripping of 8 to 12 feet of soil and red clay is necessary for the quarrying of fresh granite. The rock is a massive biotite granite of uniform medium texture and light gray color. Good dimension stone can be readily quarried. The joint-planes strike K-S. and N. SO'' to 80° W.
The Nottoway — ^Prince Edward Counties Area.
In the northwestern comer of Nottoway county and in the adjacent portion of Prince Edward county is a very promising area of massive gray granite of fine texture and uniform color, which has been opened and a little stone quarried for local use at a single point in both counties. The granite is exposed at the surface in flat-doming masses and as boulders. This area lies close to the Southern, and the Norfolk and Western Railways.
30 MINERAL RKSOUSCBB OF TDKXSOA.
The Wimgo qujury in Xottovav country locmtBd 3i» miks north of Jen- nings and 2.5 mileB south of JeteTsriUe^ on the east ode of the Sonthem Bailw«\\ was operated s<Hne years ago for ballast. The rock is a fine- gnjJDfed massive, medinm gray, biotite granite^ of nniform textnre and color. It is a desirable stone and can be nsed for any purpose made of granite.
In ti^ Ticinit}' of Rice's £>epoc« Prince Edward connty, granite was qoarried some years ago for use in bridge construction along the Norfolk and Western BaihraT.
Granite^ suitable for general building and other purposes, occurs in ocher counties of the crystalline armu but in none of these has it been derdi^wd. A beautiful coarse-grained granite is found in Buckingham co«intT« near the Court-House^ but no quarries hare been (qpoied. lakewise a coarse-grained light gray biotite granite occurs 3 miles west of Thaxton. a station on the Norfolk and Western Bailway. A red granite, well suited for omamoital and g^ieral building purposes, but underdoped, is reported from Saxe in Charlotte countr.
The Btie Biice Area.
In :he mountain district of Loudoun county, extending northward across the INxoniae into Maryland and southward into Fauquier county, Tirgtnia. granite is widely distributed in long belts up to six mfles wide. Tbe outcropt? incDEMse in extent and number southward from the Potomac
rn Tirginia.
According to Keith, the minerals compo^ing the granites are chiefly quartz* and ortKvlase and plagtcclase feldspar; besides biotite, garnet, epi^e* and blue quartz occur, fonuing four types of granite in different arcft^. The iranite :s Itrfir ^^rav in color and has been extensively altered by pressure. .Xceorviiui: to the dirtsree o{ alteration the rock is a granite, gneiss, or qtiarti >chist. Nv> quarries have been opened in the granite, but wher^ K>ulder? could be obcarued without mudi labor local use has been made of the granite.
Vaakite.
The name ucakite whs prv^iv^sevi tor a unique rariety of granite, com- pot?ev' of the essential minerals^ vellow-green eprdote, pink feldspar, and quart 5. frvnr the Unaka rangv of the Great Smoky Mountains, in North Carolina. The eff^vt of the rvvk in ei:her rock-faced or polished work is
BUILDINQ AND OBKAHSNTAL 8T0NB8. 81
quite pleasing and it might be used to good effect in certain forms of ornamental work.
Unakite occnrs in two localities in Yirginiay namely, near Luray, at Milam^s (}ap in Page and Madison counties, in the Blue Bidge; and about 2.5 miles south of Troutdale along the Marion-Jefferson public road, in Grayson county.
Hie Milam's Gap unakite is a moderately coarse but irregular crys- tallization of red feldspar, quartz, and green epidote. Irregular crystal- lization of the rock is shown in the variation of masses composed of more than two-thirds of the red feldspar through all gradations to masses composed of quartz and epidote without feldspar. Thin sections of the unakite from Milam's Gap show epidote, orthoclase, quartz, iron oxide, zircon, and apatite. The epidote is secondary, replacing pyroxene and feldspar, both plagioclase and orthoclase. The unakite from Grayson county shows deeper colored feldspar and epidote than that from Milam's Gap.
As shown by the analysis below of the Milam's Gap unakite, made by Phalen, the rock is relatively basic for a granite :
Per cent.
Silica 68.32
Alumina 15.77
Ferric oxide 6.66
Ferrous oxide 0.89
Magnesia .09
Lime 11.68
Soda 0.32
Potash 4.01
Water 1.73
Phosphorous pentoxide 48
Manganese oxide 13
Zirconia trace
Total 09.98
2. STENITK
Under the name syenite is included a crystalline granular rock which consists essentially of orthoclase, with or without one or more of the accessory minerals, mica, hornblende, or augite. It is sold on the market as granite and is used for the same purpose but differs from granite only in the absence of quartz. Most of the known areas of syenite in Virginia
32 IdXERAL RB80CBCBB OF YIBGIXIA.
contain hornblende as tbe chief locessonr minertl, and the rock is accord- in^lr a hornblende srenite.
In Charlotte connty, an exposnie of hornblende srenite has been traced from Drakes Branch, a station on the Southern Bailway, to within 2 mileB east of Charlotte conrt-honfe. a disttnce of abont 5 miles. The rock is entirelT maf^ve. Tarring from gra\ to deep pink in color, and in texture from medium to coarse-grained. It vould make a desirable stone for the TarioQs nses to which granite is pot. No attempt has been made to quarry this rock.
In Carroll cotintj, eit-aiding northward frwn the northwest edge of STlvatus, is an area of hornblende svenite. the exnosures of which show pronounced crushing and shearing from pressure nn^amorphisnu The rock in this Ticinitr cotild only be used for the rougher grades of work. Xortheastvard fTX)m Sylratus along the Carroll county line and on Big £eed Island creek, an area of coarse-grained pink homblende-biotite STCTiite^ carrring more or less quartz, oocure. Study of this area will probably show the rock to grade into a true granite.
Along the west side of the Blue Ridge and topographically bdow the basalt, a coarse-grained, massive, dark gray syenite has beoi obeerved in Warren. Madison, and Greene counties. This rock has been found along the west side of Dickey's Hill. 4 miles south of Front Bo;al in Warren county ; at Milam's Gap in Madison county where it forms the unakite-bearing rock; and between Elkton and the High Top Copper Company's mine, in Greene county. Where obseired, the syenite appears entirely maasiTe except at <me or two points in the Greene county locality, where a sdiistose structure has been developed in it. In the Warren county area the rock Taries from medium to coarse texture. The svenite of the above localities has nowhere been qt2arricd. but it should prove a desirable stone for general construc- tional work and many other purposes for which granite is employed.
According to Phalen, the syenite of Milam's Gap, Madiaon county, the unakite-bearing rock, a hypersthene-quarti-diallage syenite, is a coarse- grained dark grayish-green aggregate of essentially fddflpars and black pvroxenes. The microiscope shows the following minerals: Orthoclase, ])lagioclase, orthorhombic and monocline pyroxeiie, qnaxiZi microdine^ iron ore, apatite, and zircon, with the alteration products e|»dote, dilorite, and sericite, Phalen gives the following analysis of fte syoiite frtHft Milam's Gap:
BUILDING AND ORNAMENTAL STONES. 33
Per cent.
Silica 60.52
Alumina 16.99
Ferric oxide 60
Ferrous oxide 6.53
Magnesia 1.59
Lime 4.68
Soda 2.83
Potash 3.91
Water 88
Phosphorus pentoxide 74
Manganese oxide 25
Chromium oxide trace
Zirconia trace
Totol 99.42
A syenite oecumng in the northwestern comer of Floyd county on Lick J ork and Flat Eun, and closely similar to the northern Blue Ridge rock, has recently been described by me. The area is a large one, and the rock, both in hand specimens and' in thin sections, is strikingly similar to the syenite of Warren, Madison, and Greene counties. The microscope shows the follow- ing minerals: Orthoclase, plagioclase, microcline, pyroxene, biotite, horn- blende, garnet, quartz, and some minor accessories. The rock is typically exposed in the nickel openings on Lick Fork.
Additional areas of syenite are referred to by the older writers in a number of other counties in the crystalline area. Although admirably suited for many uses, practically no development of the syenite areas in Virginia has been made.
3. GNEISSES. The Lynchburg Area.
On the north and east sides of the city of Lynchburg is an extensive belt of gneiss cut across by the James river and lying partly in Amherst and partly in Campbell county. Excellent exposures of the gneiss are found along the James river and some of its tributaries, near the city, and numerous quarries have been opened and stone supplied for general building and street purposes in Lynchburg. The quarries are located along the north side of James river, in Amherst county, opposite Lynchburg, where the river has cut directly across a broad anticline of gneiss; and to the east of Lynchburg, in Campbell county, along the tributaries of the James river.
The stone is a fine-grained dark blue-gray biotite gneiss well suited for the uses made of it. It splits out readily into slabs of any desired
■ ■ I
; -i!
1:1 '
1
I
mt
I I
34 MINERAL RESOURCES OF VIRQINIA.
thickness, is hard but easily dressed, and very resistant to atmospheric agents. Plate VI. figure 2, is a view in one of the quarries east of Lynch- burg.
The Fairfax-Alexandria Counties Area.
Extending southward from the Potomac river and covering much ol Fairfax and Alexandria counties, are two extensive belts of gneisB, one ol which is a metamorphosed granite, the other of doubtful origizL The former rock, known as granite-gneiss, is of fairly uniform color and texture; the latter, which is of doubtful origin, is quite irregular both in color and texture, and composition as well. The granite-gneiss has been quarried quite extensively from time to time for local use, from the ledgec along and on the south side of the Potomac river.
When fresh the rock is a dark bluish-gray gneias of rather fine but uniform texture. The principal minerals are quartz, orthodaae, plagio- clase, muscovite, and biotite, with frequently small amounts of garnet, chlorite, hornblende, tourmaline, and pyrite.
The gneiss of doubtful origin has been designated by Keith, the Carolina gneiss, and is composed of alternating layers of gneiss and schi&t of a prevailing gray color, dark bluish-gray when fresh. The bands vary ii thickness. Quartz and mica are the predominant minerals in the schist; and quartz, feldspar, and mica, in the gneiss. So far as I am aware the Carolina gneiss has not been quarried in this area.
Other Gneiss Areas.
Gneisses of graniiie composition form one of the most widespread rock- types in the Virginia crystalline area, and large areas occur in many oi the Piedmont counties of the State. like their granite equivalents, from which they have been derived in part, at least, they are usually of the bio tite type, although hornblende occurs in the gneisses of the Bidmiond and Fredericksburg areas. Structurally the jrneisses vary from irregular banded rocks like those of the Kiehmond and Fredericksburg areas described abovC; to regular banded forms like the gneiss of the Lynchburg area. Texturallj they var}' from fine- to coarse-grained rocks. The more r^ularly banded ones of uniform textun* and color are suitable for general building pur noso^. and all of the Virginia gneisses are well adapted to the roughei graile>5 of work, such as for all forms of street work, for concreting and i^illast, rt^tainiiiL^ wall-, and foumlatious, and as metal for road construc- tion.
HINEOAL RBSOl'KCES Of VIKCIMA.
PLATE VI.
GRANITE AXD GNEISS QirARRIES IS VIRGINIA.
BUILDINO AND ORN AHBMTAI. STONES.
85
In addition to the quarries of gneisa opened in tbe Lynchburg area, gneiss has been quarried in Fluvanna, Bedford, and Pittsylvania counties. A gray biotite gneiss has been quarried at Columbia is Fluvanna county, and a large area of dark gray biotite gneiss is exposed for some distance Jilong the Norfolk and Western railroad at Bellevne. A similar gneiss in color, texture and composition, has been quarried near the depot at Chatham, on Cherrystone creek, in Pittsylvania county.
4. MCA SCHIST. ■
Mica schist is probably the most abundant type of crystalline rock occurring in the Virginia Piedmont region. It^ iB^Usually thinly foliated, composed essentially of mica and quartz with or wiUiont feldspar, and is quite variable in character. Because of its thinly foliated and irregular character, its uses are limited to the lover grades of constructional work. Ordinarily the rock is more or less deeply decayed and fresh expoauree of it are not very common. It has been quarried in several localities in the Piedmont region for strictly local use.
One of the best grades of mica schist yet quarried in the State is in the vicinity of Rocky Mount, Franklin county. Quarries have been opened in the schist belt, near Bocky Mount, which yields a gray rock well adapted for flagging and other purposes. The stone can be quarried in smooth slabs of any desired thickness. It has been used in Bocky Mount and to some extent in the city of Boanoke for street work. The strike of the schist is 40° east of north, with a dip of 80° to the southeast.
Production.
Value and uses of granite prodttred in Virginia from 1900 to 1906 inclusive.
|
Year. |
0 lit |
ri |
Ill |
1 1 |
» s |
1 |
|
1900 |
^,!K!6 |
»76,757 |
126.415 |
»38,850 |
fl5,833 |
f 21 1,080 |
|
IMl |
49,293 |
98, MI |
25,330 |
60,008 |
||
|
1902 |
33,858 |
80.462 |
45,191 |
78,275 |
44,470 |
282,046 |
|
1903 |
39,786 |
58,586 |
38,101 |
110,006 |
52,869 |
299,335 |
|
1904 |
50,933 |
104,060 |
67,806 |
239,335 |
48,664 |
|
|
1905 |
41,039 |
67,130 |
30.718 |
266.899 |
57.004 |
452.390 |
I«
S. TUJfXJJT
T»Rfi:I &u£ nant for sit airt. ±iiaT cn^sftlrnf, i£3iEsin$ lodL Scnne Kf tbt r/iri? :i2j£ii5e£ laiosr ^ii« rifiiiir.ii£ cf^ cmcrnac xnc kaovn com- mercialrr ^5 Kia^i rrtn:'K. 7bt nrcmtrr rrxi rwi. sdA as iJstt com-
r:tad» «ii£ tltm* :ix rvVi^Tr frnn. ocri rrsnr "a^rroui atri pwrn 10 almoet iiia;^ It i? C3:w*ftrn^c> i»i:r£ dt Txaui. bti£ al Acrnxnc a-f 13 xmriiDeeB
Ix u&«3ar Tr isi^ 129^ i^^ 7nft£ mfs&L :zr£j nr msMse f (rm? an ex- rfujfoa nutmnal fnr w'^^w: nJiK^ sxi£ ^foier&l nxziiaizir acii£ ansamental 'ip/ci^ XDnhi.^-iu: iD^TTinnmcil riCTirews^ i^nur rr -nif iari rf dsfiiite rift :ixi ^us: jT^? li rA:^ i^ifor rinr;7ian; TxsrniTt jsnc iisrmiaB. i^ift can, as a tucl. 1^ irnrir^^ nL>t v*::^. &ihrx£jrT iai£ xtsaairT si m. earn. £3«aser tiian Ak: /c rr$a::;7f:. T>imia^ ha^. iwwY^r, rif ifii£ vac? caxDk imp "man general i»r 5nr Tifc^Tru: tccttikiWv iai£ «:X TUfrt Tftwoit^ inr lazuciiir and momi-
T'TW /IT iijiiu^f AivncT^ it*io*0^ £ti5cri2it;ii»£ n^«£r iikts nf ibe Bine l^iow ian£ tW rr^^u.'.i.Ttf tr^. il T^-rr^TiU^ 1: ftrrrrrrT ir rrsai ai<iii>daiiee
:m^ *vi)itr xriv»'/TCv^ 7nt.T^ «>£ it ^-^irTj'^N. dkfi? 7%RXi{crBz:izif liit cader rhcis^ ri 7Ji\( :ry^-$,\:mt urns*, Thf ti^ijrr«' n. zxv /tcra-TriK aiiaiak filled %''iiy i;i^iftjVv Ji'Tf .*r<Kxtrr ;t r^wir. sanMcmw* inlkmrnic md
-^/r TTtfcT^ Tr. W rr. fv;'^PTm <'9rsf!< jt. ti^t f! '^-r.r.^nr. fi* Thnr* T?rai£ a3>c they xrK-*» it. %'^4^ \ -^nrt *. -i'V :TV'hfs lit ^r <u^'^ir^. \^in\t^L 5«C- 1>Iif ^rf the
T^i-?2f^'-^^Ti* .\M 1 . 'Thr ^'w ^ ^-^/^^-^r. »•• T.hf Tua tl-^bt la Xmpolis imr Vt^.f- 1/ f,r^: T< rrn<>^4-' twitV T-$4'*r **mr ihr rrvnr ac Ti«»riiie along rW Sai' W^-T '^vir *^T.^ r/ tj-n; N -Anr >^-*<-*ttiPfrrf S^tttrvm. a fistaaee of Ti>A^-r i)*ur ^l n .^^ .^.ivo- 4-!tv\> n: tju siom matsnfiL jcnd acaalQT as
BUILDING AND OBKAKENTAL STOKES.
87
large as the Pittsylvania county dike are found in other counties of the crystalline area.
The following analyses made by me of the rock from the Pittsylvania county dike, and from nearby smaller ones west of Chatham depot, show their composition:
|
Gonstituents. |
Olivine Diabase Per cent |
Olivine Diabase Per cent |
Quartz Diabase Per cent |
|
Silica |
46.73 13.48 11.60 9.92 16.40 3.24 0.47 0.94 |
47.87 14.48 11.66 10.46 10.68 8.47 0.61 1.82 |
62.06 |
|
Alumina F©rric oxide |
13.67 16 97 |
||
|
Lime MflinifflifL TTTT'-,'- |
8.16 6 01 |
||
|
Soda. Potash. Water |
8.86 0.86 1.05 |
||
|
ToUl |
100.78 3.026 |
100.78 |
100 13 |
|
Specific grayity |
2.968 |
||
In the Blue Eidge region of northern Virginia, extending from the Potomac river southward through parts of Loudoun, Clarke, Fauquier, Warren, Page, Madison, and Greene counties, are extensive sheets or flows of basalt and diabase. The basaltic rock is dense, heavy and dark-colored, and varies texturally from a basalt to a diabase, parts of which are usually altered and sometimes schistose. According to Keith the schistose character prevails in the Harper^s Ferry region, and the rock is known as catoctin schist on account of its great development in Catoctin Mountain in Mary- land. The schistose character of the rock further south in Virginia, from Front Royal southward, is much less well-defined. As a whole it appears more massive than schistose, though in places it is sheeted vertically from close jointing along shear zones.
Two varieties of the basic rocks are recognized near Harper^s Ferry by Keith, a lower diabase sheet, and an upper basaltic sheet, both altered, with the upper one largely epidotized. Thin sections of the rock show variations from fine-grained basalt to, in the coarser varieties, diabase with pronounced ophitic or diabasic texture. The principal minerals are augite, plagioclase, magnetite, some olivine, much secondary epidote and chlorite, and in many of the sections leucoxene. The following analysis
11 i
3d JfXarSRAL RSSOCBCES 09 TDttxDTLA.
made hj C. H. Henderson of fpedmen^ of the rock from South Mountain,
Maryland, shows the chemical ccaoipostion:
Silicm 41.280
AlizMiiitt IS.4S0
oziiie »-«0
Lime TiMO
* .'
Sod* X523
FotMsh ±208
IgnitJOB 2.740
ToUl IWJSr:
The silica was determined bv George Stcig» of the U. S. Geological Survey in 2 samples of the basaltic rocks, collected from the following localities in Virginia: 6 miles southeast of HarpeFs Ferry, and east of Browntown. The results were 45.66 per cent, and 46.04 per cent., respectively.
According to Campbell and Brown« about 3 miles north of Bapidan, a station on the Southern Bailwav, are to be seen two rounded knolls of
m
similar shape and size, forming rather conspicuous objects in the landscape. These are sometimes called the *Twins,'' although known by other names in the neighborhood. On top of the knob nearest to the raflroad, beautiful perpendicular, pentagonal and hexagtnial basaltic columna form the face of a cliff. Some of these columns are 60 feet high and from 20 to 25 feet in diameter. The stone from the side of the ^'Twins" is quarried under the name of granite, but it is in reality a hypersthene diabase.
Along the railroad, between Bapidan and Mitchell stationsy for a mile or more, the same rock appears in the cuts. A few miles east of Culpeper coort-houae, Mount Pony, an isolated peak, stands out so prominently that it has been used as a signal station upon various occasions. The greater part of this peak is composed of rock of the same character as the **Twins.'' Other knobs and dikes of diabase occur in this region.
I The composition of the diabase from the quarry on the "Twins,'' and
ft froifi a dik^? in the railroad cut not far from the **Twins,'' is shown in
i\ii: following analyses, made bv W. G. Brown:
I n
Per cent. P*r cent.
Hilirni 51.31 50.88
Ahiniina 13.64 13.17
f>ff»r oxi'Jli 0.52 1.11
BUILDING AND ORNAMENTAL ST0NB8. 39
Manganous oxide trace trace
Lime 12.41 10.19
Magnesia 12.73 13.05
Potaah 0.32 0.31
Soda 1.40 1.17
Titanium oxide trace
Phosphoric cxide trace
Ignition 0.14
ToUl 100.82 99.67
Specific Gravity 3.09 3.10
I. Hvperathene diabase from the "Twins" quarry.
II. Oiivine-hypersthene diabase from dike m railroad cut not far from the •Twins/
Notwithstanding the wealth of diabase of excellent quality found in Virginia, only a few quarries have as yet been opened. The principal quarries opened in this rock are in Loudoun, Fauquier, and Culpeper counties. In the former county, Loudoun, diabase has been quarried near Goose creek, about 3 miles from Leesburg. Excellent stone was found at the surface and few natural joints appear, the rock splitting with ease in any direction. Its texture is coarse and uniform, but it is darker in color than ordinary granite. The stone from this locality has been found to stand a pressure of 23,000 pounds per square inch, and, according to Merrill, the stone undergoes no change on an exposure of 25 years, other than a slight and in no way objectionable darkening of color.
In Fauquier county, near the Prince William county line a short dis- tance east of Catlett, a station on the Southern Railway, diabase has been quarried. The rock is of coarse texture, dark gray color, very strong, and apparently durable.
As yet the stone quarried at the above localities has only been used for paving purposes and for bridge abutments, although it is apparently well adapted to all kinds of work for which its color and hardness qualifies it.
In other parts of the crystalline area surface boulders of diabase have been worked up for strictly local use. Apart from the utilization of this stone in the better grades of work for which it is well adapted, it should have an extensive use, on account of its general excellence, as road metal, in the construction of permanent good roadways over the crystalline area.
DIOBITB.
Diorite is the name given to a granitoid igneous rock consisting essentially of plagioclase feldspar and hornblende. More or less black
4^ xonmAi. MEBOirscEB of nacasn.!.
micii iLjoniie) is pnesaDt. aikd quartz i^ a ecDsraaatt ia die more add TBjafiias viKB die rock is caBed gvorts-iicmu^
Itiotiie oorms easi of the Blue Ib> m i^ cz^ncaLizhe area in the form of 'diket <^f rairing widi^ peDeirai±D^ i^ cry^ttaThmf rodEX. It ia less mbnxkdasBt in TiigiiiSa liiaii diabase. T^ cniiT }oc&]liiT is de Suite known to liie wii^ET TKhert tios rodt lia§ 'heai cizarried ax aD is in the T^ini^ ^ ^uTttmrtaV aaad Falls CSmrdi in Fairfax ccnnaj. 7^ qnarrjing of dSsrite in t^is loealitr has liaen exireaDtiy YnnnfA, altboo^ it readily irarlkS mn inm Uoelrs on acrv^nni of its jDort or leas gprnrnd ftrQcture.
1^ word gahbro is tsmplofyeA to destgiaa^f a granixood igneotos rock compQBBd isf plapoelase feldspar and prroxeDe. As ^et penr little is knopvn of ihe oocnrrenoe of ihis rod: in Tiiginia. like diorite it ia limited in its •opnnTBDce to tbe crrstailine area «aflt of ihe Ktne Ridge. It has ^een icnmd in Ambersi. oo^nntr, «as$ of Lrndiimig. xai in the noidiwestem eoTDsr of Fiord ooonrr, hst do far as the writer is aware it has not been ^narriod mi but podnt in the SxaXif.
Cazcpltell &nd Brown. Compositioii c^ Oerrjdn lledoso)^ Igneona Bods
of Tiiginia. Bnlledn, Gookipcal Sooetr of Am- erica, 1891, n, s»^4$L
Banou- X. H. On ih*- Oorarrence of Basah Diifes in the Upper
Pa]«>zic Series in Centra] Appaladiian Yiiginia. With noires on the PetroirraphT hj J. S- Diller. American Journal of SoeDce, ISSH^I XXXJX, 269-
l^^^loirir Atlas of thr Fnited Stat<L Fn^derieksbnrg Folk Xo. 1,^, r, &. Geological Smrey, 18M.
Ban on, X. H. hnS. Keirh, A. On IMkis of Ff»]f*ophTT^ and Basalt in
Paleozoic Bodes in CVntral Appaladiian Viiginia. American Journal of Science, 1S9S, Yl, 305-315.
^■W^olopc Atlas of the Fnit^^d States^. Washington Folio, Xa TO. F. S. Geolodcal Smrev, 1901.
Kf-hyi, A. i^xV'Og} of the Catortin Beli^ 14ih Annual Report,
r. S- Gwiodcal Snixer, lS5^2-.J*a, Part IL 2S5-395.
Gi^oiopc Atlas of The Fnit^^a Stares, HarpePs Ferry Folivx Xo. 10. r, S, Goolorical SnTreT, 1J594.
BUILDINO AND ORNAMENTAL STONES. 41
Merrill, G. P. Stones for Building and Decoration. New York,
1897. For Virginia granite, see pages 263-264.
Phalen, W. C. A New Occurrence of TJnakite. Smithsonian Mis-
cellaneous Collections, 1904, XLV, 306-316.
Rogers, W. B. Gteology of the Virginias. (A Reprint of the Annual
Reports and Other Papers on the Geology of the Virginias.) New York, 1884.
Watson, Thomas L. Weathering of Diabase near Chatham, Virginia.
American Geologist, 1898, XXII, 86-101.
Some Further Notes on the Weathering of Diabase in the Vicinity of Chatham, Virginia. American Geologist, 1899, XXIV, 356-369.
Occurrence of TJnakite in a New Locality in Virginia. American Journal of Science, 1906, XXII, 248.
Lithological Characters of the Virginia Graijites. Bulletin Geological Society of America, 1906, XXVII, 523-640.
Williams, G. H. General Relations of the Granitic Rocks in the Middle
Atlantic Piedmont Plateau. 15th Annual Report, U. S. Geological Survey, 1895, 657-684.
Geology of the Crystalline Rocks. Washington Sheet. Maryland, District of Columbia, and Virginia. U. S. Geological Survey. Gnide to Washington, pre- pared for the International Congress of Geologists, 5th Session, Washington, 1891.
6. SLATE.
IKTBODTICTION.
Slate suitable for roofing and other purposes is found in many localities in Virginia, and quarries have been opened and worked in Buckingham, Albemarle, Amherst, and Fauquier counties. Slate of commercial value but of which no producing quarries have been opened is found in Prince William, Stafford, Fluvanna, and Craig counties. Along the northeastern base of Massanutten Mountain in the upper or northern part of the Shen- andoah valley a little prospecting in the Paleozoic black shales encourages the possibility of obtaining a reasonably good grade of black slate. Of the slate areas worked, that of the Arvonia belt in Buckingham county is the most important. The several slate belts are separately described in some detail below.
42 lUXEEAL BE9C»rECES OF VIBGIXUu
The Bnddnghaai-IlmTBUift Caaxtici Bdt.
In his aimual reports of the YirginiA Smrej from 1835 to ISil, Professor W. B. Bogers called attention to the slate depomta east of the Blue Bidge in BnckiDghaiD. FliiTaniia, and Fanqnier countieB. His reference to the Buckingham-Fluvanna slate belt foUows: ^Tliia [roofing slate] makes its appearance on both sides of the James river, dipping east at an angle of about eighty degrees with the hofriaooL In Buck- ingham the hed is largely exposed in the neighbourhood of New Canton on Slate river. ... In tt-Ature^ density and capacity of resisting atmoqdieric agents, it can scarcely be excelled by a similar material in any put of the vorld. This quarry was iirst oj»ened to procure slate for roofing the capitol: and notinthstanding it has been thus long knovn, and its Tslne established, but little further use has been made of it, until the actiTity of the present proprietor has again brought it into notice. Hie buildings of the ITniversity vill soon be furnished with a complete covering of slate from this qi^arry."
Map, figure 10. in part adopted from Dale, shows some of the important feaiurfs of this l»oiT. The belt i> crossed bv the James nver a short distance vest of Brcmo and lies partly on the north side of tbe river in Fluvanna couniy ami partly on the south side in Buckingham county. On the north side of the river the belt is approximately 1.5 miles wide and strikes X. 20"" E. On the south side of the river at Arvonia. in Bnddng- ham countv, the t»elt of commercial slate is less than 1 mile in widA and strikes X. 35 "" E.
On the nonh and south sides of the river the slate belt is limited on ihe east by a micaceous quan^ite interbedded in places with thin leaves of slate. Slate also occurs on the east side of the qnartzite. Hie strike o' the quartzite is X. 1^' to So*' E, and dips 65*^ t^ 90 * E. On tlie west side of the belt at Virginia mills there are schists largely diloritic, sericitic and quartzose in composition, which strike X. 25 *" E, and dip 90*. The belt is fr(*queTitlT traversed by dikes of olivine diabase whidi range in thickness up to 1$ feet. Several of these larger dikes are exposed in some of the larirer onarries at Arvonia.
The f.ndini! of fossils (chnoids, brachiopods, and triloibites) in the slate by Dart on at some of the Arvonia quarries shows it to be of Ordo- vician a^. ririch roferrei^ the slate on the above fossal evidence to the Tpper Ordo\icifin. The dikes of vviabasf- are of Mesozoic
UINBRAL RESOURCBS Of VIHdlMA.
Fig. 2. — Slate quarry in the Arvonia area, Buckingham county. SLATE QUARRIES, .ARVONIA. mtKIXOHAM COl NTY. VIRGINIA.
!l ■
- ■■{
'l
!■• i
■1'. .i • -
■ L . L
; ■■•■■•■
.■ ~ ;. I ' V'Ji!
1- I
1 ]
It
.'1 -I
■;; '■;
■" ."' \ -
I .
r^ -I
I "I I -I
I- I
1
■ ; :>•
BDILDIKQ AND ORHAUENTAL BI0KS8.
Fig. 10. — Hap of the Arronia ilaU area, Buckingham counl;. Qnairiea ahown bj bcav^ doti; atrike of commercial slale b; arrows. Baaed on the Palmyra topographic ahect, U. H. Oeol. Survey. Scale, } inch equali 1 mile, approximatcty. COatour interval, 50 feet.
i;..M;iiAL iii;s>>i.u>.t:.-i' ur vikgima
- Uilli«iu-> MliiiM UiiupMiy''- quarrici u i
EVt-KlNt,H.UI cxtrN-n". VIRCnOA.
BCILDIHO AND OBNAJfENTAL STONES. 45
micaceooB and the more quartzose beds are ciyBtals, lenees, and particles of pyrite, Dumbering about 25 to each square millimeter and measuring np to 0.09 millimeter, rarely 0.15 and 0.43, with their longer axes parallel to the deavage. These probably inclnde a little magnetite. There are also biotite scales transverse to the cleavage, about 22 per square millimeter, and measQiing np to 0.12, rarely 0.2 millimeter. Almost, if not quite, as abundant are plates and rhombs of carbonate. There are occasional scales of chlorite interleaved with muscovite, a few grains of plagioclase feldspar 0.047 millimeter, rarely one of zircon, some tourmaline prisms 0.014 millimeter long, much extremely fine graphitic (or carbonaceous?) material, a few particleH of hematite, and some rutile needles. Sections parallel to the cleavage are unusually brilliant in polarized light, owing to the abun- dance of quartz, biotite, and carbonate."
Becent tests made by Professor Merriman on the slate from the Williams and Pitts quarries are given by Dale as follows :
|
Color ud Bnn. |
1 S ■fol in.- |
llli |
a 1 f! |
Pi |
m all! |
||
|
Bine. WUliuna ai>i« CompMij |
W 1 W 2 W 8 W4 |
8,590 8,260 10,700 e:6» |
0.17 .19 .31 .24 |
2.78. 2.754 2.79S 2.788 |
0.073 .088 .097 .033 |
0.105 .090 .209 .167 |
0.281 .801 .223 .270 |
|
Hmo. |
9,040 |
.2r |
3,781 |
.060 |
.143 |
.394 |
|
|
BiM. A.L. ntu Qourio. |
PI P2 PS P4 |
8,540 9,010 11,970 0,B80 |
0.26 0.18 .26 .22 |
2.806 2.790 2.786 2.781 |
0.095 .159 .138 .038 |
0.332 .154 .les |
0.248 0.552 .275 .218 |
|
Mwn. |
9,860 |
.225 |
2.791 |
.106 |
.216 |
.323 |
Althon^ Dale's results on the microscopic study of the Aivonia slates ■how the presence of some carbonate, an appreciable amount of ferrous carbonate cannot be present, for the use of these slates on buildings in Richmond more than 60 years ago, and on buildings near the quarries for more than a century, show no discoloration whatever. Strength and dura- bility would naturally follow from the highly crystalline character of this slate.
46 MINERAL RESOURCES OF VIRGINIA.
Bremo. — Slate has been prospected at several places north of the James river several miles west-northwest from Bremo in Fluvanna county. The strike and dip of the slate are approximately the same as south of the river at Arvonia — ^the strike being N. 18° to 23° E. and dip nearly 90°. A dike of olivine ddabase about 10 feet wide cuts the slate about 2 miles northwest of Bremo.
The slate from near the surface is dark gray, which color will probably prove darker on depth. It differs from the Arvonia slate in finer texture, possibly lighter shade, and slightly increased pyrite; but less biotite and no carbonate. It contains a little graphite, does not effervesce in cold dilute hydrochloric acid, is sonorous, and very fissile. Arranged in order of abundance the chief constituents are, according to Dale, muscovite, quartz, pyrite, kaolin, chlorite, graphite (or carbonaceous material), rutile, with accessory tourmaline, zircon, biotite, and hematite.
A microscopic examination of this slate by Dale gave: "There are abundant quartz grains up to 0.09 by 0.03 and 0.13 millimeter long, the larger ones surrounded by secondary quartz, radiating along the cleavage; about 50 lenses and crystals of pyrite per square millimeter, measuring up to 0.09 by 0.02 (exceptionally the lenses are 1.6 millimeter long), with their longer axes in the cleavage. There are also square and rhombic spaces lined with secondary quartz, measuring up to 0.6 millimeter, left by the dissolution of cubes or distorted cubes of pyrite. In some speci- mens there are 65 such cavities to the square inch, in others none. There are lenses up to 0.56 by 0.11 millimeter, consisting of quartz and musco- vite or of these and chlorite and pyrite, or of chlorite and muscovite, the folia of muscovite and chlorite lying across the cleavage; also muscovite scales up to 0.09 by 0.02 millimeter. Throughout the matrix much dark gray material occurs in exceedingly fine dots (graphite?). There are also some dots of hematite. Rutile needles are not very plentiful up to 0.01 millimeter long; also a number of very irregular particles of rutile up to 0.05 millimeter, consisting of a network of cr}'stals ("sagenite twin- ning*') forming angles of 120° and 60°. A few fragments of zircon, an occasional crystal of dark tourmaline up to 0.05 by 0.02 millimeter, rare flakes of biotite, no carbonate.'*
The Albemarle County Belt.
The Albemarle county slate belt lies about 20 miles west-northwest of the Arvonia belt. It is reported as being crossed by the James river at Manteo, a station on the Chesapeake and Ohio Eailway, and near the
BDILDING AND OBMAMSKTAL BTONBB.
47
Nelson &ud BaddDgham county line. It has been opened at Keswick, Eb- mont, and Back Island creek. At the latter place the Albemarle elate qiiam«s were operated many years ago. Slate bas recently been prospected near Keswick. During the summer of 1906 a company begun operating a quarry near Esmont. Slate of black, green and red colors is reported from tbe Esmont qnarry.
The Amherst Coont; (Snowden) Belt.
An extensive belt of slate is fonnd on the southeast side of the Blue Bidge, in the vicinity of Snowden station in the southwest part of Amherst
Fig. II. — Mip ahoTrinfi location of Snowdwi alite <]a«rriea, Amherst conntj. QnarrieB ihowa by black dota; rtrike of commercial slate br arrovs. Baaed on the Lexington typographic sheet of the U. S. Oeol. Surrey. Scale, | iDch eqtiala 1 mile, approzimately. Contour iat«rval, 500 feet.
count)'. The belt has been prospected in a number of places in the county but only one quarry was operating during 1906, located about 3 miles north-northwest of Snowden. It is known as the Williams Brothers slate qnarry on the property of the Virginia Slate Mining Company. The quarry is further situated on the southwest side of Rocky Row Mountain just under Saddle Gap and about 1,200 feet above the James liver, as shown on the accompanying map, figure 11. The slate strikes
48 MINERAL RESOURCES OF VIRGINIA.
X. 65° E. and has quartzite southeast of it which has been referred to the Cambrian. The structure, a flat-topped anticline^ indicates a possible overturn.
The Williams Brothers' quarry was opened in 1880. The production was steady from 1893 until the burning of the mill in October, 1904. Rebuilding of the mill was in progress during the summer of 1906 and the production was expected to begin by September of the same year. The cleavage strikes N. 45° E. and dips 30° S. 60° E. The bedding is strongly marked by finely plicated ribbons of quartz and calcite several inches wide and is cut by the cleavage at an angle of 45° and more, as shown in figure 1, plate IX, Joints are well developed, striking N. 16° to 20® E. and dipping about 70° W., and a second set intersecting the first at approxi- mately right angles, and dipping at about 65° east.
The slate is very dark gray, has a minutely granular texture, moderate- ly smooth cleavage, but with little luster. It resembles the Arvonia slate in not effervescing with cold dilute hydrochloric acid and in being quite sonorous, but differs from it in not being graphitic nor magnetitic. Ar- ranged in order of abundance, the chief constituents of this slate are, according to Dale, muscovitc (sericite), quartz, chlorite, kaolin, pyrite, carbonate, rutile, and carbonaceous matter. It is used exclusively for roofing and is a superior slate though less cr}'stalline than the Arvonia slate.
Dale gives the following results of a microscopic examination of this slate: ''Under the microscope it shows a matrix of muscovite (sericite), with aggregate polarization not very brilliant owing partly to the coarse- ness of many of the other constituents. Quartz fragments measure up to 0.08 millimeter; chlorite scales and lenses up to 0.28 in length, lardy 0.42 by 0.2 millimeter, numbering about 6 per square millimeter; also mus- covite scales up to 0.09 millimeter ; some carbonate, but in exceedingly min- ute rhombs and plates ; grayish carbonaceous (?) matter; about 66 spherules tind pyritohedrons of pyrite per square millimeter, measuring up to 0.005 millimeter; abimdant rutile needles, and occasional fragments of zircon.*'
Slate was prospected some years ago on the Thompson propert}', less than 2 miles northeast of the Williams Brothers quarry. The slate closely resembles that of the latter quarry. According to Dale the strike of bed- ding is N*. 58° E. and dips 20° E., with cleavage nearly horizontal; strike of joints N. 38° E. and dips 20° W.
MINERAL RBBOL'RCBS OK VIUIilMA.
SLATE QUARRIES. SKO\VDF,K. AMHERST COUNTY, .VIRGINIA.
BUILDING AND OBSAUEHTAL BTONSS. 49
The f aaqnur Cosaty Belt
Ab shown on the accompanying map. figure 12, elate haa been quarried to the north and south of White Sulphur Springs on the Bappahannock tiTer, about 6 miles southwest of Warrenton. In his "Reprint of the Virginiaa" Profeseor Bogera referred to the quarrying of this slate as early as 1837. The slate outcrops about 1 mile south of the springs and is
traced northward for a distance of 2 miles, and has a minimam width of a half mile. The strike of the cleavage over most of the belt is N. 25° to 30° E., with a reported change in strike to an east-west direction about three-quarters of a mile south of the springs. The slate is associated with a mnscovite quartzite and with altered emptives of the homblendic and epidotic types.
Openings have been ma'Ie at a number of places which are indicated on the map, figure 12. At the two openings northeast of the springs the
,. I
iil!<
I
! I
50 MINERAL RESOURCES OF VIRGINIA.
strike of the cleavage is N. 25** to SO** E., with dip to the west of 20** to 26" Two sets of joints cut the slate in the opening nearest the springs; on( set, strike joints, strike about N. 15° E. and dip about veri;ical; the othei set, dip joints, strike N. 70° to 75° W., within most cases, neariy vertica dip. ii The slate is black, of moderately fine texture, and has but little luster
It varies from a clay slate to a mica slate. According to Dale it is ver carbonaceous, shows much pyrite, has no magnetite, does not effervesa with cold dilute hydrochloric acid, and has an argillaceous odor. In th( northeasterly opening Dale gives the chief constituents of the slate, ar ranged in the order of abundance, as carbonaceous matter, quari;z, musco vite, feldspar, pyrite, and chlorite. In the opening nearest to the springs the same author gives the chief constituents of the slate as muscovit< (sericite), quari;z, carbonaceous matter, and pyrite.
At the opening about half a mile south of the springs, the cleavage
of the slate strikes about N. 80° E. and dips south at about 15^. Th<
I , slate is bluish-black, has a coarsely crystalline texture, and a wrinkb
Jl| surface.
According to Dale this slate is properiy a graphite-quari;z-muscovite
schist, the chief constituents of which, arranged in the order of abundance
M :: I are carbonaceous matter and graphite, quari;z, muscovite, kaolin, pyrite anc
feldspar.
Dale further says that this slate has very little luster, is carbonaceoui or graphitic, shows pyrite, has very little magnetite, does not efifervesa in cold dilute hydrochloric acid, has an argillaceous odor, and is ver sonorous. After a microscopic examination of this slate Dale remarks "Under the microscope it shows a matrix of carbonaceous or graphitii material, quari:z, and muscovite. As the first two predominate the aggre gate polarization is quite faint. The cleavage is serpentine, owing to th( many large quartz grains (up to 0.14 millimeter) and the cubes and lense! or distorted cubes of pyrite already referred to, most of which seem tc be partial pscfudomorphs of quartz and graphite after pyrite, the remaining pyrite having been oxidized and dissolved. There are some plagiocla« feldspar grains almost as large as the quartz grains, with graphite inclusiooF parallel to the multiple twinning. There are veinlets of quartz and lenses of secondary quartz usually about or on either side of the cubes and lenses of pyrite; rare grains of zircon. No carbonate or rutile detected.'*
The pjnritiferous character of all the Fauquier county slates is a ted feature.
n
\
I >'■'
BUILDINQ AND OBNAHENTAL 8T0NB8.
The Prince William — StKflord Conutiei Belt.
A narrow belt of black Blate, to which the name Qnantico slate has been given from the cre^ by that name, is exposed along the "fall-line" in Stafford and Prince William counties. This belt of slate belongs to the crytalline rocks of the Piedmont region, and in its soathem portion in Stafford county the elate is in contact on the east and west sides with granites and gneisses. North of Accokeek creek in Stafford county, the belt forms the easternmost rocks of the Piedmont ctystallinea. Accord- ing to Darton the slate appears to grade on the west into siliceous mica Bchist or gneisses of greenish-gray color.
In Stafford county, the Quantico slate ia exposed in the "fall-line" gorge at Acqnia creek, northeast of Garrisonvillc, and on Austin nver; they outcrop on the road a mile east of Garrisonville ; and they reappear a mile and a half east, and half a mile south of Mountain View. Darton gives the average width of the slate belt in Stafford county as three- quarters of a mile.
The Quantico slate is exposed to the northeast of Dumfries in Prince ATilliam county, along the stream courses and wagon roads, and aloug the narrow-gauge railroad of the Cabin Branch Pyrite mine. On the west about 1 mile east of the Cabin Branch mine, the slate is in contact with crystalline schists. Large and small quartz lensce and stringers are inter- leaved with the slate. The width of the slate belt at Dumfries cannot be less than three-quarters of a mile. The cleavage strikes N. 10° to 20° E. and dips from 64° to 90° N, W. The slate is highly graphitic in places.
The Quantico slate has not been quarried to any extent and, so far as I am aware, it has not been tested. Lithologically it resembles the roofing slate quarried at Axvonia in Buckingham county.
Production. Prodvetion of slate in Virgmia by years, from 1897 to 1906.
|
Ycu |
Square, |
Valoe |
Tolsl Value |
Ywr |
Itooflng Slate, SqoarM |
Value |
Other pnrpoBW |
ToUl Value |
|
I8TB |
8.057 |
»32,228 |
$32,328 |
1893 |
27,106 |
FI04,847 |
12,600 |
$117,347 |
|
IB80 |
11.500 |
51,000 |
81,000 |
1894 |
33.956 |
118,851 |
19,300 |
138,161 |
|
1S61 |
12,000 |
54,000 |
64.000 |
1895 |
27.095 |
92,367 |
19,000 |
in, 357 |
|
1883 |
16,000 |
51,01)0 |
51,000 |
1836 |
■.'6,8fi3 |
92,163 |
15,700 |
107,863 |
|
1883 |
10.000 |
60,000 |
60,000 |
1897 |
38,375 |
130,495 |
14,875 |
145,370 |
|
1884 |
9,000 |
46,606 |
45,605 |
1S98 |
43,745 |
142,446 |
8,500 |
180,946 |
|
1885 |
17,300 |
68,137 |
58.137 |
1899 |
62,560 |
174,960 |
8,160 |
183,110 |
|
1886 |
16,600 |
69,800 |
59,800 |
IBOO |
56.385 |
186,211 |
6,000 |
190,211 |
|
1887 |
19,000 |
57,000 |
.')7,0fP0 |
1»0] |
53,630 |
178,979 |
178,979 |
|
|
1888 |
17,4(10 |
60,540 |
60,640 |
1902 |
42,731 |
160,96) |
160,951 |
|
|
1389 |
30,457 |
113.079 |
113,079 |
1903 |
29,646 |
115,3.'>6 |
118,3.'i6 |
|
|
1881 |
36.069 |
127,819 |
127,819 |
1904 |
31,862 |
130,208 |
130,208 |
|
|
1892 |
40,000 |
160,000 |
150,000 |
1906 |
36,102 |
146.786 |
146,786 |
52 MINERAL RESOUROES OF VIRGINIA.
References.
Campbell, J. L. (Jeology of the Blue Bidge, near Balcony Falls, Vir- ginia. American Journal of Science, 1884, XXVIII (3. 8.), 221-223.
Campbell, J. L. and H. D. The Snowden Slate Quarries. The Virginias,
18S4, V, 162, 163.
Dale, T. Nelson. Slate in Maine, Pennsylvania, Vermont (Northern),
Virginia and West Virginia. U. S. Geological Sur- vey, Bulletin No. 260, 1904-05, 486-488.
Slate Deposits and Slate Industry of the United States. U. S. Geological Survey, Bulletin No. 275, 1906, 154 pages; Virginia, pp. 111-119.
Darton, N. H. Fossils in the "Archean" Rocks of Central Piedmont,
Virginia. American Journal of Science, 1892, XLIV (3. 8.), 50-52.
The Geologic Atlas of the United States. Fredericks- burg Folio No. 13. U. S. Geological Survey, 1894.
Rogers, Wm. B. A Reprint of Annual Reports and Other Papers on
the Geology of the Virginias. On the Roofing Slate of Buckingham County, Virginia, 78, 79; on that of Fauquier County, 460, 461. New York. 1884.
7. SANDSTONES AND QTrABTZnE&
GEHE&AL P&OPE&TIES.
Sandstones are sedimentary rocks, composed of grains of sand bound together by a cementing material. With the sandstones are here included certain rocks of similar origin but which, through the deposition of siliceous cement, have become partially recrystallized and are known as quartzites — ^metamorphosed sandstones. The so-called Potsdam sandstone occurring along the western base of the Blue Ridge is a good example.
The sand grains in standstone may vary in size up to small pebbles and may be angular or more or less rounded in form. The cementing material varies greatly in composition, the usual ones being silica, iron oxide, and calcium carbonate. The color of the rock and its adaptabilily depends more perhaps upon the character of the cementing material than upon the grains themselves. If silica alone is present the rock is light oolozed, hard, and among the most durable of rocks, but hard to work.
«i composed largely or entirely of iron oxide, the stone is red or brown
BUILDING AND ORNAMENTAL STONES. 63
and usually works readily; and when calcium carbonate is the cementing material the stone is light-colored or gray, soft^ and easy to work. Many sandstones contain little if any cementing material, but they owe their tenacity to the pressure to which they were subjected at the time of consolidation.
All sandstones are not composed entirely of quartz grains but fre- quently they contain a variety of minerals, such as feldspar, mica, and other mineral species common to sedimentary rocks. These accessory minerals often give character to the rock and form a basis for a division into feldspathic, micaceous, calcareous sandstone, etc. Sandstones are of a variety of colors, the various shades of gray, buff, brown, and red being the most conmion. They occur in beds of greater or less thickness and are said to be thick-bedded or thin-bedded.
In age sandstones occur from Algonkian down to the most recent, although the quarrying of them at present for building purposes m this country does not include any of later age than Cretaceous.
GEKE&AL STATEMENT.
Sandstones and quartzites are found in workable quantily in each of the three larger divisions of the State. Quarries have not been opened, how- ever, in these rocks except in a few of the more favorably situated localities. Consequently there are large areas of stone of good quality in which there has not been any development.
In many areas of the Piedmont province, more or less remote from transportation facilities, small openings have been made from time to time, from which stone was obtained to supply an immediate local need. Most, if not all of these, are now abandoned. Practically the only sandstone formations in the State from which stone has been quarried for building purposes and shipped beyond the limits of the State are the Newark, and Jura-Cretaceous systems. Of these the latter has been much the most extensively quarried.
The principal sandstone and quartzite formations in the State are separately treated below under (a) the larger divisions of the State, and (b) in order of geologic age beginning with the oldest.
Coastal Plain 1. Jura-Cretaceous sandstones along the ''fall-line."
T»' J i. T»i * (2. Older crystalline quartzites of the Piedmont.
Piedmont Plateau | 3 Newark (Jura-Trias) sandstones.
Appalachian Mountains
4. Cambrian sandstones.
5. Silurian sandstones.
6. Devonian sandstones.
7. Carboniferous sandstones.
54 MINERAL RESOURCES OF VIRGINIA.
THE COASTAL PLAIN BEGIOH.
I Jura-Cretaceous Sandstone.
IP -
Sandstones of various degrees of coarseness are found in many places
along the eastern outcrop of the crystalline rocks and extending for some
I distance below the head of tide. Large exposures of these rocks arc
seen near Fredericksburg on the Rappahannock river. Other exposures
are noted at Falmouth, at the head of the Pamunkey, at a short distance
below Richmond, in the neighborhood of Petersburg, and at several othei
points in Chesterfield county, in the upper part of Greenesville countyi
, and over a considerable portion of Brunswick county.
This rock is described by Professor Rogers as a rather loose mixture of quartz and feldspar, the feldspar often decaying rapidly on exposure. In size the rounded grains vary from birdshot up to several inches ir diameter. In certain localities the sandstone has a fine dose texture, and has been employed to a considerable extent in building. The quarries in the neighborhood of Fredericksburg and Acquia creek show beds ol I considerable thickness of a homogenous rock of light gray or buff color,
which has had extended use in buildings in Washington, Richmond, and
: elsewhere.
j
; The Acquia creek quarries were purchased by the United States Grov-
■ ernmcnt in 1791 for the purpose of using the stone in the construction
I of the public buildings in Washington. The material from these quarries
was used in the construdiion of all the important public buildings that
were commenced in Washino^ton prior to 1837. The list includes the mi
! Executive Mansion or White House, begun in 1792, the central or old part
of the Capitol building, the old portion of the Treasury building, the old
portion of the Patent Office building, and the foundation of the Citjr
Hall.
The quarrying of this rock has been discontinued largely, it is said, because of its unfitness for exposed work.
Among the most extensive quarries of this sandstone formerly worked in the vicinity of Acquia creek and on the Rappahannock river near Fredericksbu;rg are the Stone, Gidlahom, Towson, Beard, and Addi^ situated near the head of Austin's Run ; the Wallace, Brooke, and Edwin- ion adjoining Acquia creek; and the Fitzhugh and Taliaferro on the l»appanhannock river. According to Professor Rogers, the thickness of the- strata exposed at these localities is very considerable, varying from 20 to 50 or more feet, presenting in the different beds of rock marked varieties of
BUILDING AND ORNAMENTAL STONES. 56
texture and composition. The sandstone quarried is light in color, nearly white, and of uniform texture. The beds lie nearly in a horizontal position and blocks of any required size are readily obtainable.
THE PIEDMONT PLATEAU EEGIOH.
The Older Crystalline Qnartzites.
Excepting the areas of Newark sandstones described below, the quartz- ites and sandstones found east of the Blue Ridge, in the crystalline area, are of unknovm age. A great abundance and variety of this type of rock occur within the limits of this area. Variation is from fine- to coarse- grained and conglomeratic siliceous quartzites; and from thin to heavy bedded rocks of usually some shade of gray color. In some areas, more or less epidote occurs and imparts more or less of a greenish-yellow cast to the rock. Feldspar and mica are frequent associates, the latter impart- ing a dark color to the rock when present in any considerable amount. Gradation is from true quartz schists on the one hand to true mica schists on the other.
The rock has been quarried in many places in years past for use as a general constructional material; and at present, quarries are operated principally for crushed stone to be used for ballast and concreting. The stone ordinarily is firm, hard and compact, highly siliceous, very durable, and is admirably adapted to the many uses that have been made of it.
Distribution, — Quartzites of variable texture and structure are found at various points along the James river between Scottsville and Lynch- burg in association with micaceous schists and limestones; and as far southwestward as Leesville, in Bedford county. To the east of Scottsville, belts of a similar rock, largely conglomeratic in places, are found on both sides of the James river in Buckingham and Fluvanna counties in the vicinity of Bremo, New Canton, and Johnson. On the eastern edge of New Market, in Nelson county, a fine to coarse granular white to red quartzite is found. At the mouth of Owens creek near Greenway the beds dip to the southeast and have a thickness of from 2 to 4 feet.
The area along James riv»er in which this type of rock is found com- prises the following counties: Fluvanna, Buckingham, Albemarle, Nelson, Appomattox, Campbell, and Bedford. In the southern part of the latter county, Bedford, at Lees Mountain about 1 mile west of Leesville, the principal rook is a fine granular slaty quartzite, which readily breaks out into masses or slabs of any regular thickness and length. Its dip is
■. ■ I
■I- 1
hi I-
ill!' III I
■1.1:
1, .
I
I-
,1
•.■il
'I I
HlttH
56 MINERAL RESOURCES OF VIRGINIA.
generally to the southeafit 60° to 80°. Some layers are hard, others ai soft. The summit of the ridge or hill is composed of the white silieeoi rock in nearly vertical layers and it has been quarried in many place The rock consists of nearly pure quartz without feldspar and mica, an it possesses beauty and durability as a building stone.
In Albemarle county two approximately parallel belts of quartzil occur. The most westerly one of these is on the immediate west side ( Green Mountain extending in a southwest direction toward Boekfis river and in a northeast direction a little west of Charlottesville. Tl: second belt occurs in Findlay's Mountain extending northeastward. Fa Hill Mountain, Applebury Mountain, and near Charlottesville in Bagge Mountain, and crossing the turnpike in a belt more than half a mile wid The rock is subject to great variation over the belts, that of the eastei belt being usually of finer grain than that of the belt west of Charlotte ville. In many places large slabs and masses of the stone are easil quarried and it is said to possess great durability as a building material.
According to Professor Rogers, quarries were opened many years aj at the following localities: On the western flank of Green Mountaii openings at various points were made and the stone was used in the coi struction of the locks and culverts of the James river canal. The bee dip steeply to the southeast and are from 3 to 4 feet thick. The gtoi is quite uniform, easy to quarry in large blocks, and it dresses readil; It is of light gray color, hard and siliceous, and contains only a fe scales of mica. On Sucker's Bun in the gap of Warwick's Mountain similar rock has been quarried. This stone is described by Professc Bogers as a hard siliceous sandstone of gray color containing both felc spar and mica, and is intersected by cross-joints. The beds dip to tl southeast. At the end of Fall Hill Mountain on the east side of Boekfis liver, quartzite has been extensively opened and used in the constructio of the James river canal. The principal opening, situated at the end ( the mountain, exposes a hard, siliceous, light^colored sandstone containiu some mica and pyrite. Professor Bogers describes the layers as being f roi 10 to 12 feet thick, of uniform texture, and well adapted for architectun purposes. His description follows: 'TSeds of grey and yellow sandstoi occasionally present thanselves among the darker rock and these are un lonnly of a coarser texture, and in many cases are rapidly decomposed b ezpoiiiie to the air and weather. Quarries of the dark greenish and bluis xodk have been opened in many places, and furnish a material for buildin
BUILDING AND ORNAMENTAL STONES. 57
which can hardly be excelled either for strength or pennanency under exposure. Much of this rock, however, is so hard as to prove diflBcult of separation in the quarry. This is remarkably the case with the green variety, which occurs very abundantly for a mile or two east of Men- weather's bridge on the Bivanna.
"The grey and yellowish-red sandstone, occurring in beds sometimes of considerable breadth, and traversing the country in the general range of rocks to a considerable distance, are found in many places to furnish quarries of very valuable building material. Such of these beds as are intersected by frequent veins of quartz, are found to be by far the hardest and most valuable. In the same bed examined at points some distance asunder, a great difference in the hardness and consequent value of the material, may frequently be observed. Thus, the bed which on the eastern flank of Peter's mountain, near Gk>rdonsville, yields a building stone which comes from the quarry in long quadrangular blocks of great hardness and durability, presents at the distance of several miles to the south a crumbling mass. . .''
In Prince William county a schistose quartzite traceable for many loiles is described as occurring in Bull Bun and Pond Mountains and in Baldwin's Bidge. Some of the layers are reported to be from 2 to 4 and more feet thick, are highly micaceous, and separate with great regularity into slabs of large size.
A gneissoid sandstone of light gray color is found in Orange county. Some of the stone has been quarried and used for steps, sills, and other purposes in the neighborhood. Exposures of the rock are seen at inter- vals along the eastern base of Southwest Mountain. The rock is penetrated by regular joints which facilitate the quarrying of large and thick slabs.
In Fauquier county less than 1 mile east of Warrenton a somewhat similar rock to that described above in Orange county is exposed over a considerable area and has been quarried for local use. Again, 4 miles west of Warrenton at the western base of Watery Mountain is a gray sand- stone which has been quarried for local building purposes and for flagging.
In Nelson county at Fabers and Eockfish, stations on the Southern Bailway, quarries opened in an irregular micaceous conglomerate are ex- tensively operated at present for crushed stone used as ballast.
58 MINERAL RESOURCES OF VIRGINIA.
The Newark (Jnra-Trias) Sandstones.
Seven areas of Newark rocks of Mesozoic age are distributed ovc the er}^stalline region east of the Blue Eidge. These are shown on th accompanying geologic map and are here designated as follows:
(1) The Xew York-Virginia area. This represents the southern poi
tion of a continuous belt of l^Iesozoic rocks which extends south westward from New York into Virginia, crossing the Potoma river from Maryland, west of Washington, and comprising part of the following counties in Virginia: Loudoun, Fauquiei Prince William, Culpeper, and Orange.
(2) The Richmond area, located about 13 miles east of Richmond ani
including parts of Amelia, Chesterfield, Henrico, Powhatan and Goochland counties.
(3) The Danville area, which extends northeastward throng
Pittsylvania county into Campbell and Appomattox counties.
(4) The Farmville area in Prince Edward, Buckingham, and Cumbei
land counties. The greatest length of this area is 22 miles an its greatest width is about 4 miles.
(6) The Scottsville area, lying mostly in Albemarle count}', but co^ ering small parts of Buckingham and Nelson counties.
(6) The Barboursville area in Orange county.
(7) The Taylorsville area in Hanover county.
The general shape and size of these areas are shown on the necom panning geologic map. The main portion of the beds forming these area is composed of conglomerates, breccia, sandstone, shale, and slate. Of thea sandstone and shale are by far the most abundant. Besides these chere ar( a few thin limestone layers, and deposits of coal. The rocks are usuall; more or less disturbed by faulting and with two exceptions they show i persistent dip to the west and northwest at angles varying from 15° u] to 70** in extreme cases, with an average much nearer the former. In th central portion of the Richmond area the rocks have a nearly horizouta position.
The greater part of the .sandstone of the Newark system in Virginij is brown or brownish-red, although occasional layers of gray sandstone occur with yellow and mottled sandstones found in some of the areas. Th( beds show considerable variation in thickness up to many feet with grada- tion into thin ferruginous shales. Likewise, wide variation in texture it shown but in many places the beds are sufficiently thick and compact anc uniform in color and texture to afford valuable building stone. It is
BUILDING AND ORNAMENTAL STONES. 59
the same reddish-brown sandstone of the Newark system that has been so extensively quarried in some of the northern and eastern states, and used so extensively for architectural purposes in the Atlantic Seaboard cities under the name brown stone.
A few quarries of this sandstone have been opened and worked in Virginia, which yielded a stone that could be used with pleasing effects in a variety of combinations, and in quality not inferior to any of that in the more northern and eastern states. The principal quarries so far worked in this sandstone are in the vicinity of Manassas on the Southern Railway, and were opened about 1868. The stone is fine-textured, light reddish- brown in color and is said to closely resemble the lighter varieties from Seneca creek in Maryland. The beds vary in thickness from 1 to G feot, with the usual thickness of 5 to 6 feet, and are separated by a greenish- colored shale. Blocks 40 by 20 by 4 feet in thickness have been loosened in the quarry, and a block containing 88 cubic feet was shipped. Accord- ing to Dr. Merrill the quarries are located near the top of a low eminence, the strata being nearly horizontal, but with a slight dip toward the south. Only the surface of the ledge has been quarried and to a depth not ex- ceeding 40 feet. Up to the time of the taking of the Tenth Census some 400,000 cubic feet of the stone had been removed.
In Loudoun county, the red and brown Newark sandstones have been quarried east of Leesburg, and to the south of Leesburg and east of Oat- lands. The sandstone beds are separated by frequent beds of shale. Quarries can be readily opened and the stone has been tested by long exposure and does not deteriorate.
' THE APPALACHIAN MOUNTAIN REGION.
Introductory Statement.
The Paleozoic sediments comprise a vast thickness of rocks, principally sandstone, shale, and limestone, which make up the Mountain province west of the Blue Ridge. An abundance of sandstone of variable composi- tion, color, texture, and structure, is widely distributed over many parts of the province, but up to the present time no special in- \estigation has been made of the qualities of the sandstones as to their adaptability and desirability for general building and construc- tional purposes. Stone has been quarried in places over the region to meet an immediate and strictly local need.
The various sandstones and quartzites of the Mountain province are
60 MINERAL RESOURCES OF VIRGINIA.
discussed below, so far as we have knowledge of them, under the geologic systems to which they belong, beginning with the oldest. These systems are the Cambrian, Silurian, Devonian, and Carboniferous.
The Cambrian Sandstones.
The Potsdam sandstone (quartziie), — The so-called Potsdam sand- stone or quaxtzite of Cambrian age, formation No. I of Rogers, is largely confined in distribution to the western slope of the Blue Bidge, and the narrow belt of rugged hills and mountains which extend westward and northwestward to the commencement of the Shenandoah or Valley lime- stone. According to Keith a belt of Weverton sandstone, which is an equivalent pari; of the Potsdam, occurs on the east side of the Blue Bidge in Loudoun county, extending across the Potomac from Maryland into Virginia in a slightly west of south course, passing a short distance west of Leesburg.
In general the Potsdam sandstone consists largely of a compact, close- grained, white or light gray rock, containing in some places, beds of a rather coarse conglomerate of white siliceous pebbles. A brownish, slaty sandstone occurs in places near the bottom alternating with the former, and towards the top it passes into reddish, brownish and olive-colored argillaceous slates or shales.
Its white or light gray color, the closeness and fineness of grain, and the almost exclusive siliceous composition, make it generally well adapted for a durable building material. In many places, the joint-planes, of which there are several sets cutting the rock, are very closely spaced, sub- dividing it into somewhat rhombic forms, do not permit of dimension stone being quarried. Where spacing of the joints does not prevent the quarrying of any size stone, the rock is so highly siliceous, compact, and close-textured, that it is difficult and expensive to quarry. So far as the writer is aware, stone for local consumption only has been quarried from the beds of this horizon.
When crushed, the Potsdam sandstone is admirably suited for ballast and concrete work. The closely-spaced joints in many places where the rock is found serve to break the stone into small sizes, much of which doe? not require further crushing. In Augusta county, about one mile east of Basic, an extensive quarry is in operation in this formation along the Chesapeake and Ohio Bailway for crushed stone. The stone at this localify la broken by nature into sizes sufficiently small as not to require iag.
BUILDING AND ORNAMENTAL STONES. 61
The Silurian Sandstones.
An examination of the accompanying geologic map> will show the distribution of Silurian rocks in Virginia. As there indicated these rocks are limited in their distribution to the area west of the Blue Ridge.
The formations comprised within this system of rocks in Virginia are made up in considerable part of sandstones. Two of these formations, the Medina and Clinton, are represented by a considerable thickness of sandstone, in many places, in the region west of the Blue Bidge. Accord- mg to Darton and Campbell, the equivalent of the Medina formation com- prises at least three different sandstones in places, each of which is designated and mapped by a separate name.
The Silurian sandstones show much variation in color, texture, and structure. In color, variation is from red ferruginous through various shades of gray to nearly white; in texture, from fine to coarse and con- glomeratic; and in structure, from thin to massive and heavy-bedded rocks. In many places where these sandstones are found their quality is sufficient to make them valuable for general constructional purposes, but as yet the demand has not been sufficient to lead to their quarrying except for immediate and local needs.
The Devonian Sandstones.
The principal sandstone of the Devonian age found in Virginia is the Monterey or Oriskany which, so far as known, has its greatest development in the middle portion of the province west of the Blue Ridge, extending northeastward, and also recognized in places further southwestward. Darton gives the following description of this rock: *^The prevailing material is a hard, fine-grained, calcareous sandstone of dark bltie-gray color, which weathers to a dirty buff, porous, sandy rock of varying hardness.^'
The thickness of the sandstone in the Monterey folio, which covers parts of Bath and Highland counties, is estimated by Darton to vary from 50 to 200 feet, and over the greater part of the area it is between 100 and 165 feet. Coarser grained phases of this sandstone occur in places. In composition, it varies from a rock composed very largely of sand grains on the one hand, to a limestone containing but few sand grains on the other, with nearly all gradations between these extremes.
So far as the writer is aware, no quarries have been opened in this sandstone. The rock is generally too friable to make a good building stone.
62 MINERAL RESOURCES OF VIRGINIA.
The Carboniferous Sandstones.
The Carboniferous comprises much the greatest total thickness of sand- stone of any geologic system in the State. The distribution of the rocks belonging to this system is entirely limited to certain parts of the region west of the Blue Ridge. For convenience of description the sandstones of this system may be treated separately under two divisions: (1) The Mississippian or Lower Carboniferous sandstones, and (2) the Fennsyl- vanian or Coal Measures sandstones. Like the sandstones of the preceding systems, those of the Virginia Carboniferous have not been investigated as to possibilities for constructional or building material.
The Mississippian group, — As is shown on the accompanying geologic map, the rocks of the Lower Carboniferous or Mississippian group are distrubuted along the middle and western portions of the Valley province, as single isolated, usually low, ridges, from Frederick county on the north to Smyth county on the southwest. In the southwestern part of the State the ridges are found near the middle portion of the Valley extend- ing parallel to the Valley axis, while farther northward they are found on the west side of the Valley as smaller and less numerous areas. (Jeographi- cally, these rocks are found to some extent in the following counties: Smyth, Wythe, Bland, Pulaski, Montgomery, Roanoke, Craig, Botetourt, Augusta, Rockingham, Shenandoah, and Frederick.
The group comprises a variable thickness of sandstone, conglomerate, and shale. A piincipal member of the group is the Price sandstone, which attains a thickness of as much as 300 feet in places. It varies from a fine- to coarse-grained rock, of yellow to dark gray and greenish color. In places, it is too badly fractured and otherwise intersected by closely spaced joints to permit of dimension stone being quarried. In other places the joints are suflBciently widely spaced to admit of quarrying stone of any desirable size. The rock apparently possesses those qualities in some localities which make it a desirable stone for building purposes. So far as I am aware, it has been used only occasionally and to a very limited extent for this purpose. It has been quarried in Pulaski county and used to a limited extent for building material in the town of Pulaski.
The Pennsylvanian group, — This group of rocks comprises a vast thick- ness (about 3,000 feel) of alternating beds of essentially shales and sand- stones partly conglomeratic, with beds of coal. The rocks are limited in their distribution to the southwest comer of the State along the Kentucky- West Vir^nia line and include the whole or parts of the following ooontieB: Lee, Scott, Russell, Wise, Dickenson, Buchanan^ and TaxewelL 13ie *«Wt
BUILDING AND ORNAMENTAL STONES. 63
lies west of the Valley region and forms the eastern portion of the Cumber- land plateau. Its eastern and southern border portions occupy the transi- tional zone between the disturbed — folded and faulted — rocks of the Valley region and the nearly horizontal rocks of the Cumberland plateau. Excepting the more or less disturbed marginal zone, the rocks of the re- maining and larger part of the area are almost flat^lying, observing a general northwest dip, as may be seen from the sections, figures 1, 2, 3, and 4, of plate LVI.
The several subdivisions of this group of rocks adopted by the TJ. S. (Geological Survey for different parts of the Virginia area which are sandstone-bearing are given under Coal on pages 336-378. Also the character of each horizon is given in the same tables.
Sandstone is one of the principal rocks of the area. Variation in the sandstone is from fine to coarse grain in texture, thick massive-bedded to thin-bedded in structure, and from white to gray in color. Not all the sandstones of this area are desirable for constructional purposes, but some cf them are sufficiently even-textured and of uniform color, over con- siderable areas, to render them economically important and valuable for building purposes, as well as for other forms of constructional work. As yet they have been but slightly quarried, owing largely to a lack of demand for the stone and to the lack of ample transportation facilities. Tliey have been quarried, however, in places for strictly local use as a building stone and for heavy masonry.
TTses.
As indicated in the table of production below, the uses made of the sandstone quarried in Virginia are as a building material in the rough and dressed state, and as crushed stone for railroad ballast, concrete work, and road-making. From the description above of the various sandstone formations, it will be observed that the State possesses a great abundance and wide distribution of this type of stone, admirably suited in many cases for the uses made of it. With the recent creation of the new State Depart- ment of Highways and the increasing demand for stone in concrete work, a substantial increase in the production of crushed stone in the State may be reasonably expected. Many of the sandstone formations described above are capable of producing stone desirable in all respects for concrete work.
The quarrying of sandstone-conglomerates in Virginia for grindstones, and the mining of sand for the various uses, are not included here but are discaased elsewhere under the respective headings "grindstones" and "sand," to which the reader is referred.
64
MINERAL RESOURCES OF VIRGINIA.
Production.
Value of sandstone produced in Virginia from 1899 to 1905.
Tear Value
1899 $ 8,000
1900 6,000
1901 6,303
1902 2,600
1903 4,471
1904 13,622
1905 2,000
Campbell, H. D.
Campbell, M. R.
Darton, N. H.
Fontaine, W. M.
Heinrich, 0. J.
Merrill, G. P.
Bogers, W. B. Bnssell, I. C.
Beferences.
The Potsdam Group East of the Blue Bidge at Balcony Palls, Virginia. American Journal of Science, 1885, XXIX, 470-474; The Virginias, 1885, VI, 99-100.
Geologic Atlas of the United States. Estillville Polio No. 12. U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Pocahontas Folio No. 26. U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Tazewell Foho No. 44. U. S. Geological Survey, 1898.
Geologic Atlas of the United States. Bristol Folio No. 59. U. S. Geological Survey, 1899.
Geologic Atlas of the United States. Staunton Folio No. 14. U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Monterey Folio No. 61. U. S. Geological Survey, 1899.
Notes on the Mesozoic Strata of Virginia. American Journal of Science, 1879, XVII, 25-39, 161-157, 229-239.
Mesozoic Formations of Virginia. Transactions American Institute of Mining Engineers, 1878, VI, 227-274.
Stones for Building and Decoration. New York, 1897. For Virginia, see pages 336-337.
A Beprint of the Virginias. New York, 1884.
Correlation Papers. The Newark System, U. S. Geological Survey, Bulletin No. 85, 1892. For Virginia, see pages 83-94.
BUILDING AND ORNAMENTAL STONES. 66
8. LIMESTONES AND KABBLES.
OEHSBAL PR0PEBTIS8, COICPOSITION, AND OCCURBENCE.
Limestone is the name commonly applied to that group of rocks which consists essentially of calcium carbonate. The rocks belonging to this group differ in color, texture, structure, and origin. They are often quite impure, the more common accessory constituents being silica, magnesia, clay, iron, and bituminous matter. These may be present in amoimts suflBcient to give character to the rock when it is designated as siliceous, magnesian, dolomitic, argillaceous, ferruginous, or bituminous. Likewise, they give rise to a variety of colors among which water-blue, green, yellow, pink, red, and shades of gray to black are common.
In chemical composition the limestones show great variation. Magne- sium carbonate may be present from traces up to the full percentage of a typical dolomite; and silica may range from a trace up to the limit where the stone becomes a calcareous sandstone. Such silicate minerals as mica, talc, serpentine, tremolite, etc., are of frequent occurrence in the more crystalline limestones.
Variation in texture, strength, and durability is as great as in com- position. They may be fine, medium or coarse-grained, and crystalline or sub-crystalline.
Those crystalline granular limestones which are susceptible of a fine polish and are adapted to decorative work are grouped as marbles. Ordi- narily, the term marble is restricted to those limestones in which the sedi- ments have been so altered and metamorphosed a? to have a crystalline texture.
Limestones are found in stratified beds, among rocks of nearly all ages from the pre-Cambrian to the most recent. Most of those used for building and ornamental work belong either to the Cambrian, Silurian, Devonian, or Carboniferous ages.
DISTRIBTrriON IN VIROINIA.
Limestone has wide distribution in the State, and is found in each of the three larger divisions, namely, the Coastal Plain, the Piedmont Plateau, and the Appalachian Mountain province west of the Blue Ridge. It is not equally distributed in the three larger divisions or provinces, nor is it of the same degree of purity. It has greatest distribution in the province west of the Blue Ridge, where it is one of the dominant rock-types. Four
€6 MINERAL EESOUROES OF YIBGINIA.
principal limestones of considerable commercial importance are prominent- ly though unequally developed in this province.
The limestone of the Coastal Plain region is of the impure eiathy form, and in this respect it is unlike that of the Piedmont and Mountain prov- inces. As a rule, the limestone of the Piedmont province differs from that of the other two provinces in being more crystalline.
For convenience of description the limestones of the State may be treated separately under (a) the larger" divisions or provinces, and (b) according to geologic age. On this basis we have the following classification of the limestones which is observed in the descriptions below:
I. The Coastal Plain limestones. II. The Piedmont Plateau limestones.
(1) The older crystalline limestones of unknown age.
(2) The Newark (Jura-Trias) limestones. III. The Mountain province or Paleozoic limestones.
(1) The Shenandoah (Valley) limestone of Cambro-Ordovician age.
(2) The Chickamauga limestone of Ordovician (Lower Silurian) age.
(3) The Lewistown (Helderberg) limestone of Silurian age.
(4) The Greenbrier limestone of Lower Carboniferous age.
THE COASTAL PLAIN LUESTONES.
The Teritiary limestones called "marls'' occur abundantly in eastern or Tidewater Virginia. They are unconsolidated or at best partially con- solidated, impure earthy limestones in no wise suited for a building stone. Their distribution and compositon are but partly known at present, but they have been extensively used for agricultural purposes, and on investi- gation will probably prove to be of considerable value for the manufacture of Portland cement. A further description of these deposits is given under the heading Marls on pages 396-400.
THE PIEDMONT PLATEAU LUESTONES.
The most abundant and commercially important limestones of the Piedmont province are the older and highly crystalline ones of unknown geologic age. More or less impure limestones of limited extent occur in th6 JnrarTrias area of the Piedmont region, but so far as known, they are €i doubtful commercial value.
BUILDINQ AND ORNAK£NTAL 8TONE8. 67
The Older Crystalline limestones.
Oeneral properties. — ^The crystalline area or Piedmont province, ex- tending eastward from the Blue Bidge, includes numerous areas of pure and impure crystalline limestones, much of which is of workable grade marble. The limestone beds of this area show much yariation in color, texture, structure^ and composition. Blue, gray, white, and pink, are, in the order named, the commonest colors. Texturally, variation is from fine- to coarse-grained, and from thin-bedded or schistose to massive in structure. In composition the beds vary from nearly pure limestones, calcium carbonate, through magnesium limestones to pure dolomites, calcium-magnesium carbonate.
The limestones of this area are associated with crystalline schists, largely of the micaceous, talcose, and steatitic types. They do not form continuous belts as in the Valley region and are therefore not persistent or continuous, but form greatly drawn out lenses intercalated with the schists. The calcareous rock is sufficiently pure to be well adapted to the manu- facture of lime, for architectural and other purposes, and in many places possesses the requisite properties of a desirable ornamental stone, for which uses the rock has been quarried in the past.
Distribuiion, mode of occurrence, and general characters, — In Albe- marle and Orange counties, a belt of slaty rocks containing embedded de- posits of limestone occurs to the west of Scottsville in Albemarle county, and extends in a northeasterly course, showing at intervals the limestone masses on Buck Island, Limestone, and Meechump, creeks. According to Professor Eogers, the limestone at Meechump contains 83.2 per cent, of calcium carbonate.
Exposures of the limestone are again shown about one and a half miles east of Gordonsville, in Orange county, and also on the road from Gordons- ville to Orange court-house. According to Professor Rogers the limestone beds at these localities are dark blue and slaty, presenting smooth talcose surfaces and occasional thin veins of carbonate. West of and between the last locality and Montpelier is foimd a bed of fine-grained marble, which bears a striking resemblance to that extensively exposed on the James river opposite Warminster, in Nelson county. The width of the exposure ia about 90 feet. The rock is white, shaded with pink, and contains occa- Bional green talc.
Doctor Henry Froehling gives the following analysis of limestone from
68 MINERAL B£80UR0£8 OF VIBOINIA.
the Buford property, near Manteo station, on the Chesapeake and Ohio Bailway, in the vicinity of Wanninster, Nelson county :
Per cent.
Calcium carbonate 54.833
Magnesium carbonate 33.524
^^^^^^^^ I 3.600
Iron oxide j
Silica 5.500
Phosphoric oxide 170
Organic matter 827
Water 1.240
ToUl 99.704
Exposures of a similar rock, some of considerable extent, are found on the Eapidan river, nearly in the general line of bearing of those referred to above. The westernmost of these occurs nearly opposite the mouth of Summerduck creek. The rock is pinkish, sometimes gray, fine-textured, and parted into thin layers of from 1 to 2 inches thick. It bums into white lime and has been used for domestic purposes and for building. Two other ledges of limestone of considerable extent are found lower down the river; the uppermost one, about 1 mile above the mouth of Brooke's run, is mostly blue, fine-granular with little or no quartz, mica or other impurities, and exists in layers several feet thick. The strike is between northeast and north-northeast with a steep southeast dip. Width of the exposure on the river is about 60 feet. About 300 yards further east is another bed about 120 feet thick where exposed, of blue and pink shades intersected by white veins of carbonate. The beds are separated into thin layers which have the same general dip as those above.
In the same general direction, limestone shows near the mouth of and on Mountain creek, in Culpeper county; and on the Rappahannock river at the mouth of Marsh run, in Fauquier county. The rock is slightly tal- cose and micaceous, of bluish color, veined with carbonate and of slaty structure. It has been quarried and burnt for lime in both counties. Simi- lar interrupted limestone beds appear in Fauquier and Loudoun counties, associated with slaty and gneissoid rocks. One of the most extensive of these is traced along the western base of Eappahannock Mountain and thence to the vicinity of White Plains. The rock is of variable color and texture, sometimes light blue and coarse-grained, and sometimes light gray with films of talc. It has been quarried at several points and burned for lime.
Further towards the northeast, a narrow bed of limestone occurs near Dover Mill on Little river, about 2 miles west of Aldie, in association with
BUILDING AND ORNAMENTAL STONES. 69
micaceous and argillaceous slates. Beyond this and in the same direction are several exposures north of the road leading from Aldie to Snickers Gap in the Blue Ridge. More or less extensive exposures are found to the northwest and near Goose creek. The rock is fine-textured, of blue color, about 20 feet wide, and has been quarried quite extensively at several places.
Marble. — Calcareous masses occur at Taylortown in Loudoun county en- closed in greenish, slaty talcose rocks. West of this are several layers of beau- tifully white marble of fine and uniform texture, free from veins, and can be obtained in blocks from 1 to 2 feet thick, and several feet long. Both the blue and the white crystalline limestone of these localities appear to be suscepti- ble of good polish.
Concerning the marble of the Goose creek area in Loudoun county, Doctor Merrill says: **White and pink marbles of excellent quality also occur in the vicinity of Goose Creek, in Loudoun county. I have seen samples of the white, which for purity of color, fineness of grain, and gen- eral excellence, are not excelled by any marble now quarried in the United States, but the extent of the deposit is as yet unknown."
Concerning the limestones of Loudoun county which Keith groups as of Cambrian age, he says : **The limestones occur in the form of lenses in the slate, and are developed along two lines, one being the axis of South Mountain, the other lying immediately west of Catoctin Mountain. Those of the eastern line are thicker and more continuous. Most of the outcrops have been worked for lime but the chief value of the limestones lies in the beds of marble along the line of their eastern outcrops. The marbles are inter- bedded with slate and schists, sometimes in one bed, sometimes in two, but the beds are generally too small to work. At Goose Creek the marble bed is about 62 feet thick and has been worked to a considerable depth. The varieties there shown are chiefly white, but there occur also, banded blue and white, serpentinized white and green, pink and white, and green and white. These beds are pure, and the stone is of great beauty, and takes a good polish; thus far, however, the lack of transportation has prevented extensive quarrying. Farther south along its range the limestone is less metamorphosed into marble and increases in thickness.
"Ornamental stones of great beauty are worked in the Newark con- glomerate and Loudoun marbles. The Loudoun marbles have not been de- veloped for commercial use, but for beauty and variety they compare favor- ably with any in the country."
An analysis of a medium crystalline, pure white, marble from Mr.
70 MINERAL IlESOURCES OF VIRGINIA.
Henry Fairfax's place, in Loudoun county, gave Mr. J. B. EofE, Jr., in the laboratories of the Virginia Polytechnic Institute, the following results:
Per cent.
InsoluhU? iiiiitter 2.12
Alumiua ) g^g^
Iron oxide j "'^
Lime 44.26
Magnesia 8.10
Lime equivalent in calcium carbonate 79.00
Magnesia equivalent in magnesium carbonate... 17.01
Verd Antique Marble, — Concerning some of the beds of marble in the vicinity of Goose creek, in Loudoun county. Doctor Merrill says: 'These same beds also produce a green or very antique marble of great beauty. The stone is an impure magnesian limestone, admixed with a large amount of serpen tinous matter. The prevailing hue is green but the stone is streaked and blotched in various shades and often brecciated. It is well adapted to interior work but the presence of abundant pyrite renders it unfit for ex- ierior application.^'
In Grayson county, near the North Carolina line, a belt of coarsely-crys- talline white to pink limestone (marble) is traceable in a southwest direction for several miles. The belt as exposed will average several hundred feet wide in places and the stone has been quarried at several points and used for making lime and as a building stone. It is quite freely streaked with large and small enclosures of a greenish silicate, which on a polished sur- face should give a pleasing effect and could be used to advantage as an ornamental stone and for the same purposes as the true verd antique mar- ble. Figure 2, plato X, is a view in one of the openings made in this belt of limestone.
Extending from Mount Athos, 5 miles east of Lynchburg, in Campbell county, northeastward to Eiverville, in Amherst county, is an extensive belt of sedimentary rocks known as the "James River Iron Belt," composed of alternations of quartzites, micaceous, talcose, and chloritic schists, and limestones. Parts of Campbell, Amherst, and Appomattox counties are included in this belt, which has a general northeast direction. Within this belt have been located a number of different limestone beds having an ag- gregate thickness of more than 1,200 feet. The stone is crystalline-granu- lar of white, gray and darker colors, and usually contains more or less magnesia in its composition. It was largely quarried and used as a flux in the old furnaces once in operaton in that section. It has also been quarried and used to some extent for making lime.
UIKERAL RBSOUBCBS OF VIKOINIA.
Fig. 2. — View in opening of marble in Grarson oounly. CRYSTALLINE SCHIST AND MARBLE QUARBIKS IN VIRGINIA.
BUILDING AND ORNAMENTAL STONES.
71
Samples of the limestone from Campbell and Appomattox counties were collected and analyzed by J. B. Britton with the following results :
Constitoents.
Per cent
II 1 III Per cent Per cent
IV Per cent
V Per cent.
Galdnm carbonate 77 67
Magnesium carbonate 3;78
Silica 15.88
Alumina 0.97
Iron oxide 1 . 16
Manganese oxide 0.07
Iron sulphide
Pbosphoric oxide 0.003
Water 0.27
Total ' 99.803
67.85 6.02
20.42 1.20 3.80 trace 0.22 0.006 0.41
82.45 2.10
10.98 0.70 2.90 trace 0.19 trace 0.16
65.10 2.96
26.90 0.86 3.94 trace
0.004 0.21
91.51 2.59 2.56
2.77
0.41
99.926
99.48
99.774
99.84
L Blue limestone from nearly vertical stratum, about 3 feet wide, on the north side of the Norfolk and V astern Railway. Supposed to be an outcrop of a stratum 40 feet wide exposed in the bed of a branch to the south of the railroad. n. Light blue limestone from stratum about 26 feet wide, about 300 yards from railroad bridge, 7 miles from Lynchburg. m. Same as II but of dark blue color. IV. Blue limestone from stratum about 50 feet wide exposed in branch a little
south of the railroad. y. White crystalline limestone from stratum about 40 feet wide.
To the east of the Southwest and Green Moimtains, in Albemarle county^ the belt of rocks including beds of limestone exposed on Mee- chump's creek and at other places is traced with but little interruption in a general southwestward course through several counties.
Professor Rogers gives the following analyses of limestone found below Raccoon ford at the end of Southwest Mountain :
Per cent.
II Per cent.
Ill Per cent
Oalciom carbonate
Magnesium carbonate. Alumina )
Iron oxide j
Silica
Water
|
77.48 5.20 |
1 90.40 6.44 |
|
1.20 |
.52 |
|
15.72 .40 |
2.00 .64 |
75.44 5.04
.92
17.92 .63
I.
n. in.
Deep pink limestone with gray white spots, compact and crystalline. Qibson
"vein." Gibson quarry, south side of the Rapidan river. Grayish-blue, compact,
semicrystalline limestone, cut by white veins. Deep blue compact limestone from Rapidan river, 300 yards east of Gibson
'Vei
ein.
ff
72
MINERAL RESOURCES OF VIRQINIA.
At Warminster, in Nelson county, the structure of the limestone is more . or less slaty and the general color of the stone is bluish-gray, frequently veined with white crystallized carbonate. At this locality the limestone is associated with talcose schist and a white and hard siliceous rock of fine texture. According to Professor Rogers: "Near the mouth of Tye river and on the Rockfish, a true marble is found of beautiful whiteness, and of a texture which renders it susceptible of a fine polish, as well as being readily wrought by chisel. A few miles from Lynchburg, in Campbell county, a good marble is likewise found, and limestone is abundant in the same neighborhood." The limestone at Warminster contains according to Professor Rogers 81.4 per cent, of calcium carbonate.
About 2 miles east of Evington, on Captain Saunders* place, on the waters of Back and Troublesome creeks, are several parallel beds of medium granular crystalline limestone, which are traceable in a general southwest- erly direction through Campbell county into Pittsylvania, in the vicinity of Toshes and Sandy Level.
This rock is associated with fine- and coarse-grained micaceous schists and in the Evington portion of the belt a hard- and fine-grained quart;. schist. Valuable deposits of an excellent grade of barite described on pages 309-318, are directly associated with the crystalline limestone in both Campbell and Pittsylvania counties, and extensive mines of the mineral have been operated at various localities in the two counties.
The limestone beds vary in thickness up to 60 and more feet. The stone is fine to coarsely granular, beautifully white with pink and darker shades shown in places, and contains in some places more or less black mica and greenish tremolite. Some pyrite and chalcopyrite disseminations occur in the stone in many localities. In structure the stone varies from schistose to massive, and it has been quarried in places to a limited extent for making lime.
The following analyses of this stone made by Dr. Walter B. EUett of the Virginia Experiment Station shows its composition to be:
Per cent
II Per cent.
Ill Per cent.
Insoluble matter
Barium sulphate ....
Barium oxide
Alumina 1
Iron oxide j
Lime.
Magnesia
Ghldiun carbonate...
'^•viMiliim carbonate.
p iQ)|iliide
|
1.66 0.62 0.40 |
0.87 0.66 0.42 |
|
0.24 |
0.30 |
|
50.04 3.28 89.36 6.61 |
52.60 1.40 99.33 2.82 |
1.10 1.62 1.62
0.96
51.00 1.85
91.07 3.73 0.36
ine limaatone from the Hewitt mine, Campbell county. Oline limestone from the Ramsay mine, Pittsylyania
BUILDING AND ORNAMENTAL STONES. 73
Newark (Jura-Trias) lomestones.
Some of the rocks of the Newark areas in the Piedmont area east of the Blue Eidge, include thin layers of deposits of impure limestone, but up to the present time no use has been made of the limestone. The doubtful quantity and quality of this type of rock in the Newark areas render it of little or no commercial value.
In describing the Newark formation in Loudoun county, Keith says: 'They [Newark rocks] consist for the most part of red and brown sand- stone and shale, beds of gray sandstone and conglomerate and limestone conglomerate being present in smaller amount. The limestone conglomerate is made up of worn pebbles of limestone of various colors usually blue, interbedded in a reddish, calcareous matrix. Rarely pebbles of slate and gray sandstones also occur with those of limestone. The pebbles were deposited in their matrix in a very irregular manner, and in sharply hmited areas.^*
The limestone conglomerate has been quarried on the Maryland side east of Point of Eocks and extensively used for interior decoration under the name of "Potomac Marble,'' and is of great beauty.
THE XOUITTAIN PBOVIHGE (PALEOZOIC) LDOEBTOHES.
The Paleozoic series of rocks comprises a vast thickness of sedimentary types which make up the entire Virginia area. Mountain province, west of the Blue Ridge. The principal rock-types are limestones, shales, and sand- stones. Of these, limestone forms one of the most important rocks in each of the larger geological time divisions, represented in the area. A variety of texture, structure, and color, is shown, which are brought out in the separate description of the individual limestones below.
There are inexhaustible supplies of limestone in the Mountain province of Virginia suitable for the various uses made of this rock. It has been extensively quarried over many parts of the area for use as a furnace flux, for lime-making in building and agriculture, for building stone, for road metal and ballast, and for the manufacture of cement, both Portland and natural.
The Umestones which have been quarried to a greater or less extent over
the area west of the Blue Ridge and used for one or more of the purposes
enumerated above, are the Shenandoah, Chickamauga, Lewistown, and
'■^cnbrier. The geographical distribution of these is given in the follow-
^S "escrfptions and in the order of geological succession, from the lowest
^ ^Ae highest.
74 MINERAL RESOURCES OF VIRGINIA.
The Shenandoah (Valley) Limestone.
The Shenandoah limestone, Formation No. II or Valley Limestone < Rogers, is the most persistent limestone formation in the State. It is ti nnderlying or basement rock of the Great Valley (Shenandoah) of Vi ginia, which extends from the Potomac river on the north to the Tenness boundary on the southwest, and lying immediately west of and parallel the Blue Eidge. It includes parts of the following Valley countie Frederick, Clarke, Warren, Shenandoah, Page, Eockingham, August Eockbridge, Botetourt, Eoanoke, Montgomery, Pulaski, Wythe, Smyth, ai Washington. Besides these it is found in Lee, Scott, Eussell, Tazewe Bland and Giles counties, in southwest Virginia. The Knox dolomite < eastern Tennessee is the correlative of a part of the Shenandoah limestoE
In its normal development the Shenandoah limestone is probably n less than 4,000 feet thick and in places it is much thicker. It is separab into several different members, which are described in some detail by B Bassler under "Cement and Cement Materials'^ on pages 93-99. Profess H. D. Campbell makes 6 distinct divisions of the Shenandoah limestone the middle Valley portion of Virginia. These are :
Period. Name of fonnation. Thickness in feet.
- _ . . (Liberty Hall limestone 1000 ifc
Ordovician | j^^^at limestone 100—160
Natural Bridge limestone 3500+
p . . ( Buena Vista shale 600 — ^900
uamonan ^ Sherwood limestone 1600—1800
According to Darton, the eastern portion of the Staunton quadrangle imderlain by the Shenandoah limestone, which comprises several membei The lowest of these is described as a thick series of dark magnesian lira stone, grading upward into a series of lighter colored beds, which conta nodules and layers of chert irregularly distributed. The upper memb of the limestone is described as a purer and more thickly bedded formatio having a thickness of from 200 to 350 feet and very fossiliferous. Accor ing to Campbell, there appears to be no way of distinguishing the top fro the bottom of the Shenandoah limestone where exposed in the Byist quandrangle.
The Shenandoah limestone shows considerable variation in charaetc It usually contains much chert in the form of nodules and layers irregular distributed through the limestone, and in some beds the chert is entire absent. The chert varies much in color and texture. The limestone much folded and crushed in places, when it is usually interlaced with i numerable vein-like lines and knife-edge stringers of white crystallizi
BUILDIKO AND ORNAMENTAL STONES.
75
calcite and dolomite. The rock has been frequently crushed and broken along certain lines into smaller masses and fragments and recemented as a limestone breccia.
Variation in the Shenandoah limestone is from a fine-granular, dark- Wue, nearly black rock, to a fine and fairly coarse crystalline light-gray, nearly white limestone. In places there appear bands of a homogeneous compact and dense-textured, light-gray limestone within the formation. The formation is marked in other places by bands or streaks of a nearly pure limestone well suited for the making of lime, for which it has been quarried at many localities. The principal member of the Shenandoah limestone, named by Professor Campbell the Natural Bridge limestone, is usually a heavy-bedded, dark-blue to gray magnesian limestone, frequently dolomitic. This is the most important member of the Shenandoah lime- stone for the production of building stone. Quarries have been opened in it in many places through the Valley region, especially in southwest Vir- ginia, and the stone used locally for building purposes. On account of its high magnesian content this member of the formation has no value as a material for the manufacture of Portland cement. The other members of the formation contain desirable material for cement manufacture, and, for this purpose, they are discussed on pages 93-99.
The following chemical analyses serve to indicate the general character of the magnesian member of the Shenandoah limestone in Virginia :
Insoluble residue
Silica (SiO.)
ntaninin oxide (TiOa)
Alumina (AlA)
Ferric oxide (Pe,0,)
Feirons oxide (FeO)
Manganese oxide (MnO) . .
Lime (CaO)
Magnesia (MgO)
Baryta (BaO)
Potash (K,0)
Soda (Na^)
Water (H/)) lOO^^C— ) . ...
Water (H/)) lOC^C.-f- Carbon dioxide (00,) Phosphorus pentoxide (PsOs) Sulphuric anhydride (SO.)
Total
Per cent
2.90 trace none 0.43 0.94
none 30.06 18.41 none 0.24 0.21
3.30
43.98 none none
100.47
II Per cent
0.594
.073
none
0.344
0.19
0.193
29.085
20.54
none
0.22
0.38
2.58
45.40 none none
99.599
III Per cent
0.45 trace none 0.24 0.17
0.37 29.50 19.93 trace 0.56 1.03
IV Per cent.
99.99
0.20 trace none 0.37 0.22
trace 30.71 21.56 none 0.12 0.10
|
8.73 |
3.92 |
|
44.01 |
43.88 |
|
none |
none |
|
none |
none |
V
Per cent
101.08
7.37
.09
1.92
0.29
0.63
none
28.39
18.30
1.09 0.09 0.09 0.49 41.85 0.03
100.63
76 MINERAL RESOURCES OF VIRGINIA.
I. Limestone. Massive, grayish-black, fine-granular, crushed and recemented with stringers of white calcite. Two and three-quarter miles southwest of Roanoke City, Roanoke county, Virginia. Dr. VV. E. Barlow, analyst. II. Limestone. Grayish white and moderately close crystalline. From the 190- foot level in the Austinville Zinc and Lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst.
III. Limestone. V^'llite. coarsely crystalline and crushed. Bottom of open-cut
in the Austinville Zinc and Lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst.
IV. Limestone. White and medium crystalline. Bottom of open cut in the
Austinville Zinc and Lead mines, Wythe county, Virginia. Dr. W. K Barlow, analyst. V. Limestone. Staunton, Augusta county, Virginia. George Steiger, analyst. U. S. Geological Survey, Bulletin No. 228, p. 306.
Numerous analyses made of specimens of the limestone, collected by Dr. R. S. Bassler, throughout its extent in Virginia, are given under Cement and Cement Materials, pages 93-99, of this volume.
The Chickamanga Limestone.
Above the white argillaceous limestone at the top of the Knox dolomite, the equivalent of the Shenandoah limestone except the basal portion of the latter, is a series of blue, flaggy limestones, known as the Chickamanga, named from Chickamanga creek in Walker and Catoosa counties, Georgia, where the rocks of this formation seem best developed. The limestone is of Ordovician age. Dr. Bassler discusses the stratigraphic sequence and limitations of the Chickamanga limestone in Virginia on pages 133-137. It becomes heavier bedded toward the base and at times is, with difficulty, separated from the underlpng Shenandx)ah limestone. Campbell states that its base is generally marked by a heavy blue bed carrying black chert which serves to fix the boundary in many places.
The Chickamanga limestone in Virginia is confined to southwest Vir- ginia and to the counties on the west side of the Valley. So far as it has been studied, the Chickamanga limestone occurs in the following southwest Virginia counties: Lee, Scott, Russell, Tazewell, Smyth, Washington, and Bland. The average thickness of this limestone for southwest Virginia is probably less than 1,000 feet.
The chief economic importance of tho Chickamanga limestone lies in the fact that it is the great marble-producing formation of the South. It is this formation that carries the famous marbles of East Tennessee. The marble of this formation (Holston) in Virginia has received little or no attention as yet and the developments are very meagre.
Along the northern base of Clinch Mountain, in Scott county, the Chickamanga limestone (Holston) carries near the bottom a variable bed of
BUILDING AND ORNAMENTAL STONES. 77
gray and red mottled marble. The marble is extremely variable in character and in thickness. In places it is highly crystalline and of good color. No de- velopments have been made in this belt. At the northern base of Big Walker Mountain, Bland county, in the great bend between Bland and Sharon Springs, the Chickamauga limestone carries marble of coarse crystalliza- tion and of light gray color. It is found in massive beds and should prove to be a desirable building stone. It has not been developed except for local use.
A coarsely crystalline marble of light color, collected by Bassler from the base of the Holston formation at Speer Ferry, Virginia, gave Mr. J. H. Gibboney on analysis :
Per cent.
Insoluble residue 0.86
Alumina | , ,^
Iron oxide ] ^'^^
Lime 55.00
Magnesia .08
Calcium carbonate 08.21
Magnesium carbonate 0.17
Total.... 100.34
Concerning the marble beds of the Chickamauga limestone in the Bris- tol folio, Campbell says: "A marble of this age [Chickamauga] is found in the Bristol quadrangle in the vicinity of Moccasin Creek, near the west- em margin of the quadrangle. It is the eastern extension of a belt of gray, coarsely crystalline marble which is particularly well shown in the vicinity of Gate City. Its texture is so coarse that it can be used only for structural purposes.
"In the great syncline south of Clinch Mountain there occur, in the carboniferous limestone, one or two narrow bands of red or mottled marble which greatly resembles the red marble of East Tennessee. Much of this Carboniferous rock is merely red, earthy limestone, but some bands are highly crystalline and full of fossils, like the best Tennessee marble.^
}>
The Lewistown Limestone.
The Lewistown limestone, the equivalent of Professor Rogers' Forma- tion VI, and the Lower Helderberg, Salina, and Niagara, of the older geologists, has wide distribution in the Mountain province of Virginia, west of the Blue Ridge. It can probably be traced entirely across the State in an approximate northeast-southwest direction, developed for the most part at the present time along the west side of the Valley, although found well within the limits of the Valley proper in many places. Further
78
MINERAL RESOUBCES OF YIBOINIA.
distribution and description of the Lewistown limestone are given on pages 151-156. In southwest Virginia, Campbell has described and mapped the Lewistown limestones under the names, Giles, for the area covered by the Pocahontas and Tazewell folios, and Hancock, for the area covered by the EstillviUe and Bristol folios.
The Lewistown limestone is usually a pure, thickly bedded, fossilifer- ous limestone, containing some cherty members and occasional sandy beds, ^tnd calcareous shales. It is especially fossiliferous in iis middle beds and in thickness varies up to 400 feet It has its greatest development in Vir- ginia in the middle Valley or Clifton Forge district, and thing considerably to the northeast and southwest of this district The thinning appears to be greatest towards the southwest. It weathers rapidly on the outcrop and exposures of the fresh limestone are comparatively few. Geologic sections and chemical analyses of the Lewistown limestone for different parts of the State are given on pages 151-156.
The two following sections, in Alleghany county, were measured by Mr. R. J. Holden at Clifton Forge and at the ford of Potts cred::
Devonian. Oriskany.
Clifton Forge Section, Alleghany Count]/,
Shale
Thin bedded Sandstone.
Lewistown <<
Good limestone
SandT limestone
Good limestone
Limestone with chert nodules
IJmestone with Brvozoa
Sandstone
Limestone, residual clay with probable limestone.
Thin bedded shalv limestone
Sandstone
Limestone, shalv
Total
Thirimww in feet
? 12
3
5 15 50 18 32 22 24
4 11
196
Section at ford of Potts Creel' , 0,5 mile above Aritts, Alleghany County.
Devonian. Shale
Oriskany. Sandstone
( Pure limestone (sandy in upper layers) ChertT limestone
Lewistown <
Massive sandstone
Coarse reddish limestone,
Thidmesa in fMt
T
6 45 55 10 10
TotAl
126
BUILDING AND ORNAMENTAL STONES. 79
Concerning the Lewistown formation in the Monterey folio, covering parts of Bath and Highland counties, Darton says : *^The formation consists of limestones which are cherty, shaly, and sandy above, more massive in the middle, and thin-bedded or shabby below. The proportion of chert in the npper beds diminishes to the south, but the presence of a cherty member at the top of the formation is always characteristic. Next below there are usually alternations of shaly limestones, which to the southeast contain some very sandy layers. There are also included some thicker layers of purer limestone. The middle members are irregular in character and vary greatly from place to place. A very characteristic member near the center of the formation is a dark-blue, wavy-bedded, massive limestone 50 to 60 feet thick, merging upward into harder, sandy limestone and hard, massive limestone with thin streaks of chert. At its base there is usually a distinct coralline bed. The lower half of the formation consists of slabby limestone merging downward into an irregular series of alternations of calcareous shales and impure limestones. . . The series of flaggy beds which con- stitute so large a portion of the formation are quite pure limestones, dark on fresh fracture, but weathering lighter on exposure. The beds are mainly from one-half to 2 inches thick, with smooth surfaces, along which the layers readily separate. To the southeast the upper part of the forma- tion includes, just below the cherty beds, a very pure, massive, fossiliferous, semicrystalline limestone.^'
"The thickness of the Lewistown limestone averages about 900 feet over the greater part of the Monterey quadrangle, but to the extreme southeast it decreases to about 600 feet.'' The limestone includes abundant fossils.
Along the western base of Little North Mountain, in Augusta county, a complete cross-section is opened near Ferrol exposing, according to Dar- ton, 200 feet of pure limestone, and farther north at BuflFalo the same au- thority states that there are several partial exposures in which about 150 feet of thickly bedded, pure limestone is seen.
In southwest Virginia, Campbell describes the Hancock limestone (Lew- istown) in the Bristol folio as follows: "Along the southern slope of Clinch Mountain the Rockwood (Clinton) formation is overlain by a blue or gray cherty limestone which is generally regarded as the uppermost member of the Silurian series and which is named from Hancock county, Tennessee.'^ It is very thin as a rule but reaches in several places where measured a thickness of 30 and 175 feet.
In the Pocahontas and Tazewell Folios of southwest Virginia, Campbell describes the Lewistown limestone as the equivalent of a part of the Giles
80
MINERAL RESOURCES OF VIRGINIA.
formation, names from Giles county, Virginia. He describes the Giles formation in the Pocahontas folio as consisting of shaly limestone, mas- sive limestone, chert, and coarse yellow sandstone. The geographic dis- tribution of the beds is uncertain, as they are generally covered on their outcrops.
According to Darton, both the Shenandoah and Lewistown limestones in the area covered by the Staunton folio are often suitable for marble, but the only attempts at its production has been in the Lewistown lime- stone at Craigsville and Bells Valley in Augusta county. The quarries at Craigsville were moderately extensive but the marble there was found to be too short and broken for profitable working.
Doctor Henry Froehling gives the following analyses of the Craigsville marble, in Augusta county:
Per cent
II Per cent.
Ill Per cent.
Calcium carbonate
Magnesium carbonate. . . . Alumina 1
Iron oxide j
Silica
Water and organic matter
95.75 1.10
1.10
.47 1.52
Total
99.94
94.95 .29
1.80
.20 2.60
99.84
96.47 1.20
.60
.41 1.21
IV
Per cent
96.43 .14
1.12
.80 1.3^5
99.89
99.84
I. Light gray marble.
II. Dark marble.
III. Dark foesiliferous marble.
IV. Red fossil if erous marble.
In many places the Lewistown limestone possesses the requisite quali- ties of a desirable building stone, but its principal use up to the present time has been as a fluxing material in the iron furnaces. It has been and ia still somewhat extensively quarried in the Clifton Forge district and used for flux. It is also quarried and used for the same purpose in Shenandoah county.
The Greenbrier Limestone.
The Greenbrier limestone, Lower Carboniferous (Mississippian) in age, is the limestone portion of Professor Rogers' formation No. XI and was subsequently named by him the Greenbrier limestone. Campbell mapped and described a Mississippian limestone in the EstillvDle and Bristol quadrangles as the Newman limestone, named from Newman Ridge in northern Tennessee. As yet full details concerning composition and local
BUILDING AND ORNAMENTAL STONES.
81
distribution of the Jilississippian limestones in Virginia are not known, ^rheir general distribution so far as known is given on the accompanying map. Description and analyses of the Greenbrier and Newman limestones are given on pages 157-158.
The distribution of the Greenbrier limestone in the State is limited to southwest Virginia, chiefly to those counties west of the Valley region proper, which m part border on the West Virginia line. These include, so fa/ as known at present, Lee, Scott, Wise, Washington, Smyth, Bland, Taze- well, and Wythe counties. It has greater distribution in West Virginia where ii roughly parallels the Virginia boundary.
In Virginia, one of the principal lines of outcrop of the Greenbrier limestone is along the border of the coal field. It generally consists of heavy blue limestone, cherty at some horizons, grading upward into thin beds of a light blue color, becoming decidedly shaly at its upper limits, and is abundantly fossiliferous. It varies in thickness, ranging according to Campbell, from 900 to 1,000 feet in the Tazewell quadrangle; from 1.200 to 1,700 feet in the Pocahontas quadrangle; and approximately 1,000 feet in the Bristol quadrangle. At Big Stone Gap, Wise county, the formation is 930 feet thick, composed in its upper part of calcareous shale, grading downward into shaly limestone and hard blue cherty limestone. In the Clinch syncline, Campbell estimates its thickness to be at least 1,500 feet. It is, so far as its composition is known, a non-magnesian limestone, a fact which renders it especially desirable for certain commercial purposes.
The Greenbrier limestone has only been utilized to a small extent in Virginia and strictly for local purposes. At Big Stone Gap, Wise county, the lower layers of the limestone are quarried and used for flux in the iron furnace at that point. Lime in abundance could be produced from many of the beds of limestone should the demand be sufficient to warrant the working of quarries. It will probably prove to be in the future an impor- tant source of material for cement manufacture in southwestern Virginia.
The following are analyses of the Newman (Greenbrier) limestone from near Cumberland Gap, quoted by E. C. Eckol in Bulletin No. 285 of the United States Geological Survey:
Per I Per cent, cent.
Per Per cent. ' cent.
Per cent
Per cent.
Per cent.
Per cent.
SiO,
CaOO,. . . . MgCO,. . . .
1.40 1.00
1.86 0.96
94.57 94 85
3.03
2.33
|
5.05 |
4.20 |
2.00 |
2.80 |
1.32 |
4.12 |
0.74 |
|
1.86 |
1 . 50 |
1.00 |
0.90 |
1.2:^ |
0.42 |
0.24 |
|
90.05 3.04 |
89.54 4.76 |
94.57 2.50 |
91.72 4.58 |
95.62 1.32 |
87.10 3.30 |
95.50 2.79 |
5.78
0.46
90.90 1.46
B2 MINERAL RESOURCES OF VIRQINIA.
Marble is partly described above under the diflferent limestones with which it is associated west of the Blue Hidge. The localities are given above so far as they are known. Under the present heading is assembled in r^<um6 form, with some description, the principal varieties of marble found west of the Blue Eidge, chiefly from color standpoint.
Bands occur in some of the limestones of this region, especially the Shenandoah and Chickamauga, of a color and texture adapted to orna- mental purposes. There are according to Professor Bogers and other more recent geologists numerous varieties of these marbles which are distin- guished chiefly by their color. The special varieties mentioned are:
(1) A dun-colored marble of homogeneous and coarse texture, and sus- ceptible of fine polish. According to Professor Rogers, this is perhaps the
most abundant marble of good quality found in the northern and middle counties of the Valley. It is met with near New Market and Woodstock, rnd on the opposite side of Massanutten Mountain, in Page county, and has been traced for some distance both north and south.
(2) A mottled bluish marble which occurs a short distance west of New Market and may be traced for many miles. It is described aa being a somewhat coarser grained rock than the dun-colored marble.
(3) A gray marble occurring some three-quarters of a mile southeast of Buchanan near the contact of the Potsdam sandstone and the Valley limestone. It is of variable color, ranging from white to gray, and is a massive, ^viupaet. tine-grained rock. As exposed in Stone Run the bed is about 50 vards wide.
{A) A white marble of exquisite color and fine-texture occurs about 5 miles from Lexington, in Rockbridge county. Professor Bogers says that the marble of this particular locality can scarcely be excelled in suscepti- bility of jH>lish, fineness and evenness of grain, and purity of color. Marble of similar a>lor but not so abundantly nor of such excellent quality, occurs at other localities in the Valley.
^5) A rt\l marble o^vurs in several of the southwestern counties. |>v>fessor Roi^ers dt»s^Til>eil a n\l marble from near the base of Angel's Bed Mountain, in iiile^ county, and one of the same here in the neighborhood of i'haf>tnan*s tVrrv. In Sinnt ^'ounty a mottled marble occurs in con- •uliTttblo quant UY a sliort Jistamv to the we?t of the Court-House. In the VhIU\ |»oriu>n v^t ihi> r\*^ion the dun-<\>lored variety of marble and others
^t'o \ <h<uK\l inarl»!<« is fouuvl in Kov*kingham county, which is said to
BUILDINO AND ORNAMENTAL 8T0NE8. 83
be compact^ susceptible of a beautiful polish, and of a yellowish-gray and slate color. This variety is a compact, fine-textured rock, susceptible of a good polish, has been opened and to a small extent worked in Bocking- ham county.
(7) A black marble is found several miles northwest of Blacksburg in Montgomery county, which is a very compact, fine-textured, homogeneous rock and is susceptible of a good polish. It is found in considerable quantity outcropping on a number of adjoining farms and has been opened in a small way on Dr. Kibble's place, but systematic quanting has not been attempted. The rock is beautifully homogeneous in color, and, unless the thin knife-edge seams of calcite do not prevent the quarrying of dimen- sion stone, it should prove to be a most desirable ornamental stone.
Cave (onyx) marbles, — The stalactitic and stalagmitic deposits and crusts on the walls and floors of the limestone cave and caverns, so abundantly developed in places through the Valley region of Virginia, west of the Blue Bidge, furnish, when cut, occasional fine pieces of the so- called onyx marble. Of these, the Luray caverns, in Page county, are the largest and best example in the State. As Doctor Merrill remarks, the stone from this source is too easily fractured and too uneven in texture to be worked economically, even though the deposit were of suflicient extent to warrant the opening of quarries. Concerning the cave marbles in general. Doctor Merrill says : *^ut at best the cave marbles of America must rank as 'uniques' rather than objects of commercial value. They will never become regular sources of supply. There is too much waste and too much uncertainty regarding amount and quality.''
ITses.
An examination of the table given belo\^ of production of limestone in Virginia, shows the varied uses made of the stone. All purposes for which limestone is used are shown. These include :
(1) Building stone. Limestone is one of the popular building stones ▼here it is convenient to market and possesses the requisite quality and color. Marble, the crystalline variety of limestone, is the most valuable variety. The limestones found west of the Blue Bidge in Virginia have keen used to a considerable extent locally for building purposes. Each «f the principal limestone formations described above has been utilized fa) some extent for building.
(2) Boad material and ballast. Nearly all varieties of limestone are used for road material and ballast, but those which combine good wearing qualities with cementing properties are the most desirable. Considerable
84
MINERAL RESOURCES OF VIRGINIA.
limestone has been used in places in the Valley region for this class of work. It is probable that a substantial increase in the quarrying and crushing of limestone for this grade of work will be shown in the future in the Mountain region of Virginia.
(3) Concrete. Limestone, crushed to gravel size or for special grades of work to flour, is used with cement for concrete. The utilization of limestone in the State for this purpose has only begun. Inexhaustible supplies of stone suited for this purpose are found west of the Blue Ridge.
(4) Lime and cement. Limestone of proper composition is used in the manufacture of lime for building and agricultural purposes and in the manufacture of both natural and Portland cement. Large quantities of limestone are quarried over portions of the Valley region and burned for lime. Natural cement is made from an impure argillaceous limestone, of which large supplies of this grade of rock occurs in Virginia and has been and is being quarried for the manufacture of natural cement. For the manu- facture of Portland cement a pure limestone or one containing a mini- mum amount of magnesium carbonate is essential. A good grade of Port- land cement should contain in the finished product not more than 3 per cent, of magnesia. Inexhaustible supplies of limestone of excellent grade for the manufacture of Portland cement are found in the region west of the Blue Ridge. Only one plant, however, has yet been established in Virginia for the manufacture of Portland cement, namely, the Fordwick Portland Cement Company at Craigsville, in Augusta county. The cement materials and cement industry in Virginia are discussed in full elsewhere on pages 86-167.
(5) Furnace flux. Limestone is extensively quarried west of the Blue Ridge and used for fluxing material in the iron furnaces over the region. Each of the principal limestone formations described above yields some material for this purpose.
Production.
Value of the production of limestone in Virginia hy years from 1900 to
1905 inclusive.
Yeir
1900 190P 19(>2 1903 1904 1905
|
Building purposes |
Paving, road- making, etc. 8,721 27,675» |
Made into lime |
5Slone sold to lime burners |
Crushed stone, etc. |
Flux |
|
5 070 2,270 41,355 5,32o 9,160 6,090 |
151,687 230,810 241,984 336,461 277,519 396.434 |
237,840 595,929 220,001 199,989 65,085 180,676 |
|||
|
8,758 "i,*665 * |
77,985 19,455 25,743 38,249 25,774 |
||||
ToUl
403,318
986,177"
634,113*
569,205*
890,118«
608,974
> Includes West Virginia.
* Includes 42,750 for other purposes.
* Includes 22 for riprap.
* Road-making' included under crushed stone. < Includes 11,818 for other purposes.
* Includes 105 for other purposes.
BUILDING AND ORNAMENTAL STONES.
85
Britten, J. B.
CampbeU, H. D.
Campbell, M. B.
Darton, N. H.
Beferenoes.
Analyses of Campbell and Appomattox County, Vir- ginia, Iron and Manganese Ores and Limestones. The Virginias, 1881, II, 170-171.
The Cambro-Ordovician Limestones of the Middle Portion of the Valley of Virginia. American Journal of Science, 1905, XX, 445-447.
Geologic Atlas of the United States. Bristol Folio No. 59, U. S. Geological Survey, 1899.
Geologic Atlas of the United States. Pocahontas Folio No. 26, U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Tazewell Folio No. 44, U. S. Geological Survey, 1897.
Geologic Atlas of the United States. Estillville Folio No. 12, U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Franklin Folio No. 32, U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Monterey Folio No. 61, U. S. Geological Survey, 1899.
Geologic Atlas of the United States. Staunton Folio No. 14, U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Nomini Folio No. 23, U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Fredericksburg Folio, No. 13, U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Harpers Ferry Folio No. 10, U. S. Geological Survey, 1894.
McDonald, Marshall. Report of a Geological and Mineral Examination of a
Portion of the James Eiver Iron Belt. The Vir- ginias, 1880, I, 10-12.
Merrill, G. P. The Onyx Marbles: TheLr Origin, Composition and
Uses, Both Ancient and Modern. Annual Report U. S. National Museum, 1893, 541-585.
Stones for Building and Decoration, New York, 1897. For Virginia, see pages 117-119.
Rogers, W. B. A Reprint of the Geology of the Virginias. New
York, 1884. Contains a wealth of information on the Virginia limestones and marbles.
Russell, I. C. Correlation Pajpers, Newark System. U. S. Geologi-
cal Survey, Bulletin No. 85, 344 pages.
Keith, A.
|
;.;u: |
i. : ■•■.: 1. Tf* »-,Tir |
|
N*: |
vr.*". \lv.*".;r.-.. «r..> |
|
. ,- |
;f- * JL".^^ :T;.y>:<\; |
Of these. :be I-.tt-:*::;:*?* lul siitl'f* :f iV5r' '.-m.^ uc-: i."^ :w JW» promisinr ce s:o:::^: :: ii-plt u.tafiLii.'f.. tiStkc:*: :.s:-m:;'M^ »?s venallT faroTir'.e iierij.-al ;-.Tn :«.ifiT3.-c. ri>f '<^-jiff,'TT ^.tm^b-vom » tiJ^ used in the mt^^iinz^ ::' rrc-itui .■xEpfci t: v'~i.i>-' •.'-. ^liJ;•^KS» conntT. and the Gre-;-":r«r -^Msr.-cjf ■»-..". 7-T.Vit:C^ rw.-,.— •; *t TtTV<-rAM sonrce of cenieiLj ^iz^zC :i ftMni-rwri'-:. V-.T-i-r*.
This anic'e :? "r-tst-i -7'-"i^ i'*-- »tt-£ :■ :>* *r«- A;-r.; "i; <.-.7T.TMrt of 1905 and IfC't.. .:2.:er -j* fnsrs^:* .-: ■;:.•€ V- 5^ i^vO-v,"*^ >^."«f;i *t»?. fte Viiginia Gecli-'j-.^-il s^xttji. a :Ti.-.-f ,vi':*:>5 tw^-- : v.-.\-(r, :Sf s»-w* tnbject will shonlj >* T-^i'-iiiii; ij t. B'^V.rt.r. .-f ;>f V-,?y.T t t^*>A'-.x; ■,■»'. Srurey.
Most of the U]a>s^ izx*-: -^ 0» ff.-"«.r.£ Ttt<rt-s *(^ Tn*."f b\ V- ._ H. Gibboney of the V:rr'^-i r.-.T-.iv'r.-^^- 1- r ftmuhed by lir. W.r: TssiJS .--i :hi V. * '. Ghsrliia Catlrti rf ?-;iz=;.-7.. V-.-r.=.:*. 7i
lofeBaor H. P. r»n:p:«ci; cf Wtsh-.::^:,-! ir..-. Ijo-. V- ii-ts:> ;>t vsv:;-* 1 ^hcrtMKraiihi of Inc*!:::;* in i>i.:nl ineSfTa Y.rj: r.>. Tr:;' Y-,t^*,t;-,*
1 of their |-lact.
xms or cxMEiT.
Pt tlie nmnerfua V:ecs of .rn-.eE:;ii^ tna;*':-.*.*. v'n">- :hiv«> wh-,.h «•;
l^intiiri that i*. hjdraclic oemems. art- ui bo .vnsi.Wrnv. ;n !V.c ;>t*«'«5
Wlit^u rtiBiparatiTely pure lini«ii>iii' is b.cai^:. ^arivn i!;**\'aV
Loff end ijnick lime results. This, as is »re':l snown. «;" slsi.f
iddilios of water. If, however, the oriirinal limwiowe i.w.i*;ni\l
IddIim, and iron oiide. in certain pro^vrt ions, the i^>s«'.t5iij; hurmxl
B affected bv water only when i;nely invxind; and ihis jH'wdor
[■ cement.
■ Or grfinps of hydraulic wmont are n>i.\^jn>i»>l. «»d n>rtl.-
inofactare occur in Virginia. Theso thrw class^'s, m tin*
biportance, are: (1) Portland cement, (?> ntiniral n-mont.
i cement.
rture of Portland cement, a fim>ly gnmiiil mi\iinv is>ii-
, alniaina, and iron oxide, in cxadly liolorniiniM (woimr-
la temperature approaching S000° F. 'riiii" bwniiiijt jm*-
masB called "clinker," which, as a Ins) nlop in thr
etnre, must be fineK- ground. The thttm'tit'iil mixtnri-
|rcoasists of 75 per cent, of I'Hictnm ■•iirlniiiiitc, V'H
86 MINERAL RESOURCES OF VIRGINIA.
II. CEMENT AND CEMENT MATERIALS.
By R. S. Bassler.*
The growth of the cement industry in the United States during the last ten years has been equalled by that of no other non-metallic structural material. This remarkable growth still persists and bids fair to continue because of the ever increasing building operations of the country. The recognition of cement as a most valuable structural material, and its ad- vantages over many other building materials in the matter of cheapness and durability, will always cause it to be regarded as a staple article of manufacture. A region, therefore, containing the natural materials from which cement can be made, has economic resources which, Sooner or later, will prove of great value. In this respect Virginia is pre-eminent. The Appalachian Valley and the various mountains and valleys westward, a tract 350 or more miles long, and averaging 50 miles in width, contains limestones and shales apparently equal in value and abundance to those of any other region.
Geographically the state of Virginia may be divided into three parts, the first being an eastern division commonly known as the Coastal Plain, the second, a large, plateau-like central area bounded on the west by the Blue Ridge Mountains, and the third, a western portion including the Valley of Virginia and the various valleys and ridges westward to the State line. Considered geologically, these same divisions may be main- tained. Cenozoic and more recent rocks underlie the eastern portion of the State; the very ancient crystalline rocks, with a few comparatively small basins containing Mesozoic deposits, are exposed in the central area, or Piedmont plateau, while all the main divisions of Paleozoic strata are tQ be found in the western part. Raw material suitable for the manufacture of cement occurs in both the eastern and western divisions, but the nature of this material in the two areas is so different that it has been deemed best to consider them separately. The present report deals only with the lime- stones and shales of the larger western area.
Four prominent sources of cement material obtain in western Vir- ginia. In geologic order these are:
4. Greenbrier (Mississippian) limestone.
3. LewifttoHTi (Helderberjrian) limestone.
2. Ordovician (Trenton, etc.) limestones and shales.
1. Cambrian — impure limestone and shale.
^Published by permission of the Secretary of the Smithsonian Institution.
CEMENT AND CEMENT MATERIALS. 87
Of these, the limestones and shales of Ordovician age are the most promising on account of their abundance, widespread distribution, and usually favorable chemical composition. The Lewistown limestone is now used in the manufacture of Portland cement at Craigsville, Augusta county, and the Greenbrier limestone will probably become an important source of cement material in southwestern Virginia.
This article is based upon field work by the writer during the summers of 1905 and 1906, under the auspices of the U. S. Geological Survey and the Virginia Geological Survey. A more detailed report upon the same subject will shortly be published as a Bulletin of the Virginia Geological Survey.
Most of the analyses quoted in the following pages were made by Mr. J. H. Gibboney of the Virginia Polytechnic Institute, but a few were kindly furnished by Mr. Wirt Tassin of the U. S. National Museum, and by Mr. Charles Catlett of Staunton, Virginia. The writer is also indebted to Professor H. D. Campbell of Washington and Lee University for notes and photographs of localities in central western Virginia. The Virginia Portland Cement Company has also kindly furnished cuts and notes on the operation of their plant.
KINDS OF CEICENT.
Of the numerous kinds of cementing materials, only those which set Tmder water, that is, hydraulic cements, are to be considered in the present connection. When comparatively pure limestone is heated, carbon dioxide is driven off and quick lime results. This, as is well known, will slake upon the addition of water. If, however, the original limestone contained silica, alumina, and iron oxide, in certain proportions, the resulting burned mass will be affected by water only when finely ground; and this powder will be a hydraulic cement.
Three classes or groups of hydraulic cement are recognized, and mate- rials for their manufacture occur in Virginia. These three classes, in the order of their importance, are: (1) Portland cement, (2) natural cement, ^d (3) Puzzolan cement.
In the manufacture of Portland cement, a finely ground mixture con- taining lime, silica, alumina, and iron oxide, in exactly determined propor- tions, is burnt at a temperature approaching 3000** F. This burning pro- duces a semi-fused mass called "clinker,'^ which, as a last step in the process of manufacture, must be finely ground. The theoretical mixture employed for burning consists of 75 per cent, of calcium carbonate, 20-
88 MINERAL RKSOIRCES OF VIRGINIA.
per cent, of iron, alumina, and silica, and 5 per cent, allowed for mag- nesian carbonate and other substances. This ideal composition is seldom realized in nature, and, as a rule, an artificial combination is made by mix- ing limestone or marl with clay or shale. In this case, one part of the clayey materials is generally added to three parts of pure limestone.
The following are the more important particulars in which natural cements differ from Portland cements:
(1) Natural cements are made from the rock as it occurs in nature and not from a tinely ground artificial mixture.
(2) The natural cement rock is burned at a considerably lower tem- perature.
(3) Natural cement is usually of a different color and of lighter weight than the Portland.
(4) The natural cements set more rapidly than the Portland but do not have so high a tensile strength.
Puzzolan cement is simply a mechanical mixture of powdered slaked lime with either a volcanic ash or a blast furnace slag. This mixture when finely ground will act like an ordinary hydraulic cement. In view of the materials in Virginia suitable for the manufacture of Portland and natural cements, Puzzolan cement is of slight consequence and is not discussed further. Again, Portland cement has become of so much greater impor- tance than natural cement, that the few pages toward the close of this contribution devoted to the latter are deemed sufficient.
CEICENT MATERIALS.
It is the writer's intention to discuss only the more important cement materials of western Virginia and to indicate their distribution.
The most important materials in western Virginia for the manufacture of Portland cement are pure and argillaceous limestones, shales, slates, clays, and marls or calcareous tufa.
A theoretically pure limestone is 'composed entirely of calcium car- bonate, but, as might be expected, limestones, as quarried, differ more or less widely from this composition. The principal impurities of limestone are magnesia, silica, iron, and alumina. Magnesium carbonate often occu- pies the place of part of the calcium carbonate and in that case a more or less magnesian limestone results. Should the magnesian carbonate be pres- ent in quantities over 5 or 6 per cent., the rock is of no value as a Portland cement material. The impurities silica, alumina, and ircn, however, when
I CEMENT AND CEMENT MATERIALS. 89
combined in the form of clay, are often favorable components of a lime- stone to be used for making cement.
Shales, slates, and clays are essentially compounds of alumina and silica with iron oxide and other impurities. Shales are clays hardened by pres- sure while slates differ only in having an even, parallel cleavage developed by the same means. As cement materials, these are of value for mixture with the purer limestone in order to bring the rock to the proper composi- tion for burning.
The marls or calcareous tufa of the Appalachian Valley are usually carbonate of lime deposits from spring water. Such material has been used in the manufacture of Portland cement, but in view of the more abundant limestones and shales, it can hardly be considered here as of economic importance.
BISTBIBTTTION OF CEICENT MATERIALS.
The most important cement materials of western Virginia are found in the pure and argillaceous limestones of Cambrian and Ordovician age, and in the calcareous and argillaceous phases of the Ordovician shales. These shales and limestones have a wider distribution and are usually more ac- cessible than such other cement rock horizons of the State as the Lewistown of Helderbergian age and the Mississippian or Subcarboniferous Green- brier limestone. In general the entire Valley of Virginia is underlain by the Cambrian and Ordovician limestones, while the shales usually outcrop along the base of the mountains bounding it. In a similar manner, many of the valleys west of the Great Valley show these limestones and shales, higher formations occurring on the separating ridges.
A study of the Cambrian and Ordovician rocks of Virginia has shown that the State may be divided into three more or less well defined areas, in each of which the geologic sequence differs to some extent. Considering all cf the State west of the Blue Ridge as western Virginia, these three areas may be designated as the northwestern, central western, and southwestern portions of Virginia. According to this somewhat arbitrary division, northwestern Virginia embraces that portion of the State north of the southern border of Rockingham county, while central western and south- western Virginia are divided by the southern and southeastern borders of Roanoke and Craig counties.
The major portion of northwestern Virginia is included in the Valley of Virginia. Almost all the cement materials of the area are confined to
M mXERAL KE60URCE6 OF TJaGOilA^
ontcrops in the Yaller and to foothills of the mountains whidi bomd The Blue Ridge on the east is made up of qnartxites and other suited for cement manufactniey while North and Shenandoah oeenpying the portion of the State west of the TaUer, are compoeed strata of sandstones^ qnartzites, and diales of Silurian and Detonian also xmsuitable for this purpose.
In a general way the geologr of this portion of the State is quite Xorth of Strasburg the Taller is broad, rather lerd, and Aaws two of limestone separated by a belt of shale, which aTerages 4 miles in and occupies the central portion of the Valley, its western edge p^RJ^g east of Strasburg and Winchester. A structure aectiim across die Vi from the Blue Bidge to little Xortfa Mountain, about the latitude Winchester (see page 106) illustrates the relati<m of the limestGoe shales in this area. Maasanutten Mountain occupies the ooitzal pcRticn dt^ the Taller south of StHgbiBng.*ejte9ding southwest as far as the latitefRri- of Harrisonburg. , Here aUo the general geology is quite simple and shown by the structure section on pace 106.
The geologic feature of'^ihis area, mo>i important from an enuMaatf -
standpoint, is the gceat downfold of strata occupying die central part of tiki Talley. North of Strasburg* the strata enclosed in this downfold 4|, « syncline have been worn down to the general lerel of the Talley« but ^odUt, * of this town, a deep sag in the syncline brings the more resistant Mat*
sanutten quartzites below the general level of erosion of the nei^iboix^g mountains. Thus when, as a result of subfe^^uent erosion, the Great TallBJ was forme«i. Massanurten Mountain, on accoTint of its hard quartzites, left as a rid^re di Tiding the Shenandoah Tallev. On account of the tion of Massanurten Mountain to this downfold. this syncline has called the Massanutten Mountain syncline.
Pure and argillaceous OrdoTician limestones are brought to the s alonr the eastern and western sides of the Massan.itten Mountain si hence its economic importance. Along the wesrem side, the normal quence of strata is usually exposed, but on the easrem side. OTerthmid faulting is not uncommon. This faulting is usuallv sui^cient to cut out tiha limestones which are of economic imr»ortance, the dolomitic strata thni-?! upon the Upi>?r Onlovician shales,
A A. 4.
The .-.'nx narrow area lying between the Massan^^rren Mountain ani the Bl-e Ridge is oc^iipitxl by dolomitic limestones and shales ar^ •:■'. n*. :n::.>ortance as a source of Portland cement rock. Just west of ttt jT-'Mt ^vrclin**. pure and artr^laceous limestones occur in co:
OEHENT AND CEMENT MATERIALS. 91
abundance, but the central portion of the western half of the Shenandoah Valley is again occupied mainly by the less valuable dolomitic limestone. The latter strata continue to the foothills of Little North Mountain, where, when faulting has occurred, they may be found resting upon the Ordo- yician shales or upon still higher formations.
When the structure is normal along the western edge of the Valley, essentially the same sequence of strata may be observed as farther east, with the exception that here the Trenton formation is composed mainly of lime- stone instead of shales, as in the more eastern localities. In addition to the Massanutten Mountain syncline, a few smaller synclincs exposing the Ordovician shales and limestones have been noted in the Valley, but these are usually of slight consequence. The most important of these minor synclines lies just west of Harrisonburg.
In central western Virginia^ the more'' important areas of outcrop of cement materials are: (1) a narrow strip following the Massanutten Mountain syncline which terminates, iji this area, (2) a considerable out- crop of argillaceous limestone itt tfei vicinity of Lexington, and (3) a rather broad band of limestones and ' shales " just east of Little North Mountain.
From a geological standpoint, southwestern Virginia may be considered as composed of elongated, narrow, northeast-southwest blocks, in each of which strips exposing favorable cement materials are found. The location of these strips and description of their contained cement materials are given later on.
CAXBBIAK AND OBBOVICIAK FORMATIONS OF NOBTHWESTEBN VIBOINIA.
Nearly all of the sedimentary rocks exposed in northwestern Virginia are of Cambrian and Ordovician age. The economic importance of the younger strata and of the area occupied by them is so small that they are not considered in the present description of the stratigraphy. Four well defined groups of these rocks have been recognized in this part of the State, namely, the sandstones, quartzites, and shales of Lower Cambrian age, the Shenandoah limestone belonging in part to the Cambrian and the Ordovician, the Martinsburg shales of the Middle and Upper Ordovician, and the Massanutten sandstones hitherto regarded as Silurian. Of these four main divisions the Shenandoah limestone and Martinsburg shales only are of economic interest in cement manufacture, and, therefore, their subdivisions will be considered more in detail. The relations and general character of these formations are expressed in the following table :
<ll MINERAL EESOCKCES OF VIKOINIA.
by Professor Campbell as the Sherwood limestoEC, cODsists of white cry line dolomites with heavily bedded light blue and gray magneaiaQ 1 stone and occasionally more argillaceous limestones and shales. It i the latter occurrence that the formation may prove of some value. 1 argillaceous limestones and shales have a composition which will t of their use, particularly in the manufacture of natural cement, principal outcrops of the Sherwood limestone are to be found aloi rather narrow strip just west of the Cambrian quartzites and shales.
The succeeding formation, the Buena Vista shales, is of econi interest because limestones suitable for the manufacture of natural cei alternate with the shales, especially in the lower part. This formRti< the source of the rock used by the natural cement plant near Bal' Falls, Virginia.
The hoa^'}'•beddod gray and light blue limestones, distin^ished Prof. Campbell as the Xatural Bridge formation, compose the : persistent formation of the Appalachian Valley. The strata are ab invariably dolomitic and upon wealbering leave a mantle of chert J ments. This chert is especially abundant in the upper beds, wl geologically, are the equivalent of the Knox dolomite of Tenneaaee. St and shaly layers are often found in the lower third. Economically sidered, the Natural Bridge limestone is of little importance. Thi especially true in regard to its use as a cement rock, the magnenan tent- lieing too high, as the following analypis will show:
Analysis of l^alural Bridge limestone, just west of Strtuiburg Junction, Virginia.
(J. H. Gibboney, Analyrt)
Per MUt.
Insoluble lO.M
Iron o-tide (FeJD,) and ahiinina 1.\Ih(),) 1J)0
Lime (CaO) 28.W
Cali-iiim <';irlHmnte (l'n<'<),) .11.07
MagnwiR (MgO) 18J)0
Magnesium carbonate (MgCOi) 37.80
Total M.03
Following the Natural Bridge formation is a series of limestt which, economically considered, are of greatest importance. These I stones arc of Middle Ordovicinn age and are composed in large par argillaceous and highly calcareous strata. The succession in this pai Virginia is most clearly shown in a section commencing west of Strasi Junction, Shenandoah county, and extending eastward to the vicinit
UINRRAI. RESOtnCES OF
SATUBAI. BRIDGE, VIRGINIA.
n ■
> ^
CEMENT AND CEMENT MATERIALS. i)5
StrasbxLTg. Here the western side of the syncline forming Massanutten Mountain brings up the strata in regular order and excellent exposures may be found along the Southern railroad between the two places mentioned and in the neighboring quarries and creeks. This section is as follows :
Oeologic section in the vicinity of Strashurg, Virginia.
Feet 4. Martinsburg shales (Trenton, Utica, Eden). Gray and black shales, calcareous at the base, then more argillaceous, passing upward into
sandy layers 2,000
Z. Chambersburg (Black River) formation. About 400 feet of blue and argillaceous limestone arranged in the following order: (i) Earthy gray limestone and calcareous shales with numerous fos- sils, TretaspiSy Christiania, and several species of Pleotambonites
occurring most abundantly 40
(h) Light gray earthy limestone, no fossils observed 30
(g) Massive dove limestone holding numerous specimens of a large
species of Nidulitea 65
(f) Rather thin bedded dove limestone with NiduUtes rare 60
(e) Thin bedded dark gray argillaceous limestone 52
(d) Thin bedded argillaceous black .limestone 22
(c) Nodular argillaceous dark blue- limest^^ t«1th numerous fossils of which Solenopora^ severaf "Speoiea of VKifilopfirina, Echinospw —
rites, and Christiania, are especially abunttant . « .. 3i>
(b) Crinoidal limestone 10
(a) Crystalline blue limestone, cherty in the upper part but pure in lower part, bryozoa abundant but a species of Subulites is especially characteristic of this bed 80
Total thickness of Chambersburg formation 398
2. Stones River formation. About 900 feet of more or less pure and magnesian limestones, the upper 100 feet consisting of heavily bedded, pure dove limestone (90 to 97 per cent. CaCO,) with occasionally a black layer. In the vicinity of Strasburg Junction these beds are extensively quarried for lime. The remaining strata consist of heavily bedded, alternately arranged layers of pure and magnesian limestone. The presence of abundant gastropoda of Stones River types and the characteristic fossils Tetradium cellulosum and Leper- ditia fabulites in the uppermost layers determines the age of this formation. 1. Typical Natural Bridge dolomitic limestone weathering into character- istic chert.
Stones River formation. — The Stones River rocks in northwestern Virginia are, in general, heavy-bedded dolomitic layers alternating with purer limestone strata. In color and texture, the rock varies from fine- grained dove to a dense black with dove-colored rock predominating. Many of the layers run as high in magnesia as the underiying Natural Bridge limestone, but the Stones River formation differs in that at least a few pure limestone layers are found in almost every exposure. Another method of distinguishing the two formations lithologically lies in the <jharacter of the soil to which each gives rise on weathering. The soil
9G
MINERAL RESOURCES OF VIRGINIA.
resulting from the decomposition of the Natural Bridge limestone is of a deep red color and generally contains a considerable number of chert fragments scattered through it. Stones Eiver rocks, on the other hand, give very little chert, on weathering, and areas underlain by them may often be distinguished further by the fact that the resulting soil seems to be particulariy suited to the growth of cedar trees. Indeed, the presence of a considerable number of cedar trees in an area of Ordovician strata is quite a reliable sign that the underlying rocks are of Stones River age.
Although the analyses of the Stones River rocks show a considerable variation in lime and magnesia, still the strata can be divided chemically into two general classes, the purer and the dolomitic limestones. The purer limestones are generally of fine-grained texture and of a dove color, al- though darker strata are sometimes interpolated. These dove and dark layers occur most frequently near the top of the formation so that this portion may generally be depended upon to furnish the purer rock. Strings of calcite often penetrate this dove limestone and give the characteristic ^'birdseye" markings. With the exception of number II, all of the analyses in the table below are of samples from the upper portion. The lower strata of the Stones River formation often show a high percentage of magnesia and silica. Their value in the present connection is, therefore, corre- spondingly small.
Analyses of Stones River limestones in northwestern Virginia.
(J. H. Gibboney, Analyst)
SiO,
AljOj and FeA
CaCUj
MgCO,
Total
I Per cent.
O.Sfi
0.(»8
09.01
0.45
II Per cent.
56.26 4.82
33.88 1.91
99 . 90
96.87
Per cent.
3.11
0.64
94.82
1.53
100.10
IV I V Per cent I Per cent
9.10 1.32
86.8 .7
99,95
8.06
1.14
87.68
1.81
98.69
I. Pure dove limestone, upper part of Stones River, Strasburg, Va.
II. Siliceous limestone, lower part of Stones River, Woodstock, Va.
III. Compact black layers in upper part of Stones River, Riverton, Va.
IV. Black limestone in upper part of Stones River, Riverton, Va.
V. Dark blue splintery limestone, Stones River, Mt. Horeb Church, Va.
Chambersburg formation. — About 400 feet of more or less pure and clayey limestones intervene between the top of the Stones River formation and the base of the Martinsburg shales in the vicinity of Strasburg. Al- fhongh these strata correspond in position to the Black River formation
CEMENT AND CEMENT MATEKIALS. 97
of New York, their lithologic and faunal differences were found to be so great that the new name, Chambersbiirg, was proposed by Stose* for their reception. The rocks of this formation are well exposed in north- western Virginia, particularly along the Massanuttcn Mountain synclino, but the most detailed section is to be had at Strasburg. By reference to the section on a preceding page, it will be noted that 9 beds are dis- tinguished, these varying in lithology from siliceous blue limestone through purer blue and dove limestone to argillaceous strata, and finally, at the top, calcareous shales.
As stated before, the detailed section exposed so well at Strasburg can- not be made out in its entirety at many, if at any, other places, and there- fore the follov^nng generalized section is introduced for the recognition of the rocks in any part of northwestern Virginia. The thicknesses given in this section are those observed at Strasburg where the rocks are believed to be well developed. Therefore it must be remembered that in other localities considerable departure from these figures may be observed.
Generalized section of the Chamhershurg formation in northwestern
Virginia,
(Martinsburg shales of Trenton, Utica, and Eden age at top)
Feet
4. Gray earthy limestone with numerous fossils in upper part 70
3. Thin bedded and massive dove limestone Jiolding Nidulites in more or
less abundance 125
2. Xodular and thin bedded gray argillaceous limestone with numerous fos- sils in lower third 104
1. Pure limestone with cherty portions 90
The more persistent members of the (^hambersburg formation are the massive dove and crystalline limestones holding Nidulites in abundance (bed 3), and the argillaceous limestones in which Tretaspis and Christiania are especially characteristic fossils (bed 4). These two divisions may be recognized in almost ever}' section, but the otlier members are seldom so well shown as at Strasburg.
Bed 4 was recognized at practically every outeroj) of the Chambersburg formation and was found as far south as Fort Defiance in Augusta county, where the thickness had apparently diminished greatly. Moreover, at this locality it rested upon the Murat limestone, which, in turn, overlapped upon a thin bed of Stones River rock, thus indicating the relations between the rocks of northwestern and central western Virginia as here subdivided.
Mourn. Geol., XIV. 1906, p. 211
•
98
MINERAL RESOURCES OF VIRGINIA.
Portions of bed 4 approach a cement rock with an ideal chemical composi- tion more nearly than any of the other divisions of the Ordovician lime- stone.
The southernmost exposure of bed 3 noted was at Harrifionburg, but more careful search will probably reveal its presence south of this city. The comparatively low dip of the rocks, forming the eastern limb of the syncline just west of Harrisonburg, causes the exposure of bed 3 in this region to be relatively wide. Along the western side of the Massanutten Mountain syncline the dip is steeper and the width of outcrop is therefore much less. From the viewpoint of cement manufacture, these dove lime- stones can be relied upon to furnish the purer rock for mixture.
A considerable variation in the composition of the various strata com- posing the Chambersburg fonnation is to be expected because of their diverse natures. Still these strata in general terms may be divided into (1) more or less pure, dark or dove-colored compact limestones, and (2) into dark, argillaceous limestone. Upon this classification, the analyses of these rocks in northwestern Virginia have been arranged and presented below:
Analyses of more or less pure, compact limestone , Chambersburg formation,
northwestern Virginia.
(J. H. Gibboney, Analyst)
|
I Perct. |
II Per ct. |
III Perct |
IV Perct |
V Per ct |
VI Perct |
VII Per ct |
1 VIII Perct |
IX Perct |
1 X XI 1 Perct i Perct |
|
|
8iO.. |
2.32 0.24 96.43 1.00 |
43.50 5.50 47.86 2.18 |
12.10 1.48 84.64 1.68 |
8.68 1.32 88.71 1.34 |
10.04 1.46 86.67 1.54 |
4.60 0.56 92.00 2.79 |
8.68 .94 90.36 .41 |
80.72 3.52 62.78 0.71 |
12.R2 1.84 81. W 2.62 |
1 16.32 4.04 |
|
Al/>,A Fe,0, CJftCOa MgCO, |
1.84 82..% 0.21 |
1.80 85.40 8.98 |
||||||||
|
Total... |
100.08 |
09.04 |
99.90 |
100.05 |
99.61 |
99.95 100.39 |
97.73 |
98.25 |
99.22 |
99.60 |
I. Unusually pure blue limestone, lower part of formation, Strasburg, Va. II. Siliceous blue limestone, lower part of formation, Strasburg, Va. Ill and IV. Dove limestone, middle part of formation, Strasburg, Va. V. Dark blue limestone, lower part of formation, Woodstock, Va. VI and VII. Dark blue compact limestone, Harrisonburg, Va. VIII and IX. Semi-crystalline limestone, Harrisonburg, Va. X and XI. Dark blue limestone, Mt. Horeb Church. Va.
These analyses and those following are here brought together for com- pariaon of the chemical constituents of these and other strata.
CEMENT AND CEMENT MATERIALS.
99
Analyses of dark, argillaceous limestones, Chamhershurg formation,
northwestern Virginia.
(J. H. Gibbonej, Analyst)
I Per Ct.
II Pfer Ct.
Ill Ter Ct.
IV Pfer Ct
V
Pfer Ct
VI Per Ct
VII Per Ct
VIII Per Ct
IX Per Ct
8iO,
Al^, and Fe,0,
CaCO,
MgCO,
Total
19.78 1.88
74.28 0.82
96.76
12.00 2.26
84.21 1.13
99.60
14.88 2.38
80.36 2.18
99.80
18.20 8.00
70.00 2.00
98.20
15.88 0.92
82.76 0.44
99.99
16.84 7.49
74.14 1.00
98.97
23.24 3.22
71.07 1.72
99.25
37.06 3.60
57.46 1.47
99.59
14.68 1.88
81.71 0.05
98.32
I and II. Gray, argillaceous limestone, middle and upper part of formation, Strasburg, Va.
III. Argillaceous limestone, upper part of formation, Woodstock, Va.
IV. Argillaceous limestone, Mt. Jackson, Va. V. Argillaceous limestone, Riverton, Va.
VI. Argillaceous limestone, 5 miles east of Woodstock, Va. yil. Argillaceous limestone, Harrisonburg, Va.
VIII. Argillaceous limestone, 3 miles west of Montevideo, Va. IX. Knotty, argillaceous limestone, Mt. Horeb Church, Va.
Martmsbnrg Shale Oroup.
No sharp break occurs between the argillaceous limestones and calcareous shales forming the upper part of the Chambersburg formation and the overlying Martinsburg shales. From an economic standpoint, no arbitrary lines of separation need be given, since the lowest beds of the Martinsburg shales are as highly calcareous aa the topmost part of the preceding forma- tion. Paleontologically, however, the two divisions may be separated by the total absence of the characteristic Chambersburg fossils in the succeed- ing shales.
In general, it may be said that the lowest deposits of the Martinsburg shales are fine, calcareous to argillaceous shales, dark drab in color when fresh, and yellowish when weathered. Higher up in the series, brown or black micaceous shales are encountered, while toward the top, the rocks become more siliceous. The thickness varies considerably, but in this part of Virginia, 700 to 2,000 feet expresses their variation, although in other regions as much as 3,000 feet have been measured.
Three divisions of the geological time scale are represented in the
Martinsburg shales. These are, in ascending order, (1) Trenton, (2)
Utica, and (3) Eden. Although the actual lines delimiting these diviaiuna
Me difiBcult if not almost impossible to determine, yet in a general way
it may be stated that the lower calcareous portion is of Trenton age, the
100
MINERAL RESOURCES OF VIRGINIA.
brown or black shales are XTtica, and the upper gray and buff shales, or siliceous portion, belong to the Eden.
The Martinsburg shales weather into a yellow and brown clay soil which is in marked contrast to the red soil of the limestone areas.
Trenton shales. — That portion of the Martinsburg shale group, of Trenton age consists of calcareous and argillaceous strata of a dark drab color and with a thickness as yet undetermined. This thickness is probably over 100 feet and less than 300, but undoubtedly varies considerably in different areas. Considered from an economic standpoint, the Trenton phase of this shale group need not be distinguished from the underlying Chambersburg shales and argillaceous limestones, as both wnll prove of use in cement manufacture.
The main outcrops of the Trenton shale are parallel with and contiguous to the Chambersburg formation. The main exposures in northwestern Virginia are therefore along the flanks of the Massanutten Mountain Bvncline.
The following analyses of shales from the Trenton portion of the Martinsburg group show such a high percentage of lime that the rock, chemically at least, may be considered as an argillaceous limestone with a higher silica content than usual. These analyses also indicate a close similarity in composition to rock from the same geological horizon but from distant localities.
Analyses of calcareous shales, Trenton horizon of Martinsburg group.
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide (Fe^Os) and alumina (AlsO,).
Calcium carbonate (CaCOj).
Magnesium carbonate ( MgCO,)
Total
I. Strasburg, Va. II. Harrisonburg, Va.
II Per cent
30.56 3.82
61.07 3 44
98.89
Trenton limestones. — Along the western side of the Appalachian Valley in northwestern Virginia, the Chambersburg formation is followed by thin-bedded limestones w^ith interbedded dark shales instead of the dark calcareous or argillaceous shales just described. The surface of
CEMENT AND CEMENT MATERIALS.
101
these limestones is often covered with fossils characteristic of the typical Trenton formation of New York. The rocks themselves, moreover, are very similar to the corresponding New York strata so that there is every reason to believe that they are identical.
The development of limestones and shales instead of shales alone, along this portion of the Valley, is of importance in that an additional cement rock is furnished. Unfortunately, the geologic structure and transportation facilities are such that at present little development of this rock could be expected. Moreover, the dolomitic limestones are generally thrust upon the Martinsburg shales or higher formations along the western side of the Valley, thus cutting out the strata of economic value. Still this limestone must be accounted as one of the cement re- sources, and analyses of the rock are therefore introduced below :
Analyses of Trenton limestone a/nd shale, Mt. Horeb Church, Va.
(J. H. Gibboney, Analyst)
Per cent
II Per cent
Insoluble
Iron oxide (Fe^Os) and alumina (Al^Og).
Calcium carbonate (CaCOs)
Magnesium carbonate (MgCO,)
Total
7.80
.90
90.64
1.04
100.38
I. Shale band. II. Thin bedded, compact limestone.
Utua shale, — This and the succeeding Edon shale are two of the most constant divisions of the geologic succession of western Virginia and, with careful search, the characteristic fossils of both may be found in almost every section exposing the upper two-thirds of the Ordovician shales.
In comparison with the preceding shales, the amount of calcareous niatorial in the Utica shale has been greatly diminished, so that, except for mixture, the rock will probably never prove of much use as a cement material. In view of the large amount of calcareous and argillaceous strata underlying the Utica shales, the necessity for the use of the latter need not arise, and there is no occasion for considering the formation as a source of cement rock. However, an analysis is introduced at this point for comparison with the associated strata.
f
108 MINERAL EE80URCES OF VIRGINIA.
Analysis of Vtica. shah, Mt. Horeb Church, Va.
(J. H. Gibbonay, Analyst)
Per cent.
Insoluble 43.04
Iron oxide {Fefi,) and alumina (AlA) 6-18
Calcium carbonate (CaCOi) 49.93
Magnesium carbonate (AlgCOi) 0.07
Total M.1K
Eden shales and sandstones. — Following the few feet of shales Cincinnati, Ohio, holding cliaracteriBtic Utica foBsilB, are 250 feet of I limeptanes and shales before strata of Lorraine age are reached. these (lie term Eden, defined by Orton in the firat volume of the "Geol of Oliio," is used in the Cincinnati area. These beds contain great numl of lirvozoa and brachiopods and are essentially thin blue limestones i-hales. Proceeding eastward, these beds become more arenaceous n in the Appalachian Valle}' sandy limestone and shales have taken the p of the purer limestones of the west. On account of the Intervei Appalachian coal field, this thange cannot bo traced continuously, but relations of the strala and their fossil contents prove the correctDess of correlation beyond a doubt. Because of the high silica content, the G shales of the Appalachian Valley are of no value as a source of cen: miiterinl.
Uauanntten Sanditone Oroop.
At many places the crest of Ma.=sanutten Mountain is composed of : yellow, and wjiite sandstone and quartzito, which, on account of tl conspicuous occurrence along this mountain, were named as above. ' Slassanutten sandstone is divisible into two numbers, corresponding i general way to the Bays sandstone and Clinch sandstone of the soutti Appalachians. The lower member is 200 or more feet in thickness ; consists of micaceous sandy shales, coarse sandstone, and conglomer Portions of this division contain ihe characteristic Bays sandstone tot which indicate the Lorraine ape in terms of the general time scale. 1 lower division has been mapped in Virginia and Pennsylvania under name of Juniata sandstone. Kragnvnls from the cliffs of the overh (]uarti^ite generally obscure this member so that good exposures are J One of the localities where fossils may be found is at Buzzard's Roosl Ihc northeast end of Massanutten Mounlnin.
The upper or Tuwarora member of the Massanutten sandstone is ni ii|> of coarse conploin crates and (lunrtzilcs, varying greatly in thieki
OEMENT AND CEMENT MATERIALS. 103
but reaching a total of at least 500 feet. Fossils are scarce, although the characteristic Atihrophycus alleghaniensis may be found upon careful search.
6EHEKAL GEOLOGY AKD STRATIGRAPHY 07 CSHTRAL WESTEEH YIBGIHIA.
The general geology of this division, although somewhat similar to that of northwestern Virginia, begins to assume the complexity of the area farther south. The great faults of southwestern Virginia are found in its southern part, while the Massanutten Mountain syncline and the structure along the western edge of the Valley in the northwestern part of the State may be traced through the northern part of the division. In the inter- mediate zone, namely, in Rockbridge county, the Ordovician limestones are so situated as a result of faulting, folding, and erosion, that a con- siderable area is underlain by them.
The principal features eoneerned- in. the exposure of the Ordovician strata are indicated on the ac^oippaiiyihg structure sections. The Massa- nutten Mountain syncline enfdrs the district from Rockingham county and occupies a portion of Augusta county, thus bringing these limestones and shales to the surface as far soiith as Greenville. The faulting along the western edge of the Valley becomes less and less in Augusta county until the structure becomes practically normal. As a result, the cement lime- stones are more abundant in this part of the Valley than northward along the same line. In the vicinity of Lexington, the argillaceous limestones are found over a considerable area, and on account of close folding, seem to be of great thickness.
South of Rockbridge county, the principal Ordovician outcrops follow the bases of the mountains and are thus exposed usually at some distance from railroads. Moreover, on account of the unusually steep dip of the strata, the outcrops are in long, narrow areas.
The regions of outcrop thus far noted are in the Appalachian Valley proper. West of this, namely in Alleghany, Bath, and Highland counties, anticlines are found, exposing these shales and limestones as their lowest strata. With the exception of the vicinity of Hot Springs, these anticlinal areas have no railroad facilities.
With a few exceptions, all of the geological divisions described previously tor northwestern Virginia may be found well developed in the central western part of the State. These exceptions are the Stones River and the Chambersburg formations. The interval between the top of the Natural Bridge limestone and the base of the Martinsburg shale is here occupied almost invariably by the Murat and Lflberty Hall limestones.
MINERAL IIE80LRCE»S OF VIKGINIA.
-ntnii w-«T*t<TTi \'ir<rinia. the Stones River rocks are practically
:;"i^rtr. \ -w :irf'Hs <ho\v a .flight development, but as a source of cement
■i;U:*r':ii *:.»• '••rniation may Im? neglected. The succeeding Murat and
..»»*r-" ri.i:i .•rii»*>tf)nesi correspond in a general way to the Chambersburg
f'lirttinn oi r\w u\nrv northern parts of the Valley, although lithologi-
1.. '. :'i) rniubif will be encountered in separating these different divisions.
1 .'av\ . iiiTtv \m\s of the Natural Bridge limestone are usually
.• tiwwi .IV it ma>>ive t^ray. coarsely crA'stalline pure limestone to which
•..^.oottjif 4 Hiii|»i)eil has applieti the name Murat from its occurrence along
^uXMft r.r«Kik ai Mural, Virginia. The limestone, as a whole, runs very
■jui -u ' i«a:iuiti rarl>onate and, for this reason, it is the source of the lime
.'4/,4«t.; *w <!*:%ei'ttl |M>iuts in central western Virginia. The lower portion
...*;• ^...**4 »U*-A'i nodules upon weathering, and it was from this part that
L. : 4. ..,,•*:« Ill rhc following table giving a high silica content were
.'.t.t .^-.: AiHiui r^5 feel of the Murat limestone are exposed at its type
.^.i... i; ,..1 Jr*'i|Ui.'iJtly ihe thickness is not so great.
. 1 tuUyses of Murat limestone, (J. H. Gibbonej, AnalTst)
|
1 |
11 |
III |
IV |
V |
|
|
i'vr ccuU 1 HO |
l*>Br cent. |
Percent. |
Percent. |
Percent. |
|
|
'H » |
5.92 |
11.72 |
1.58 |
1.62 |
|
|
/, /,' i.L': Ai/>. |
0 22 |
.43 |
6.16 |
.34 |
0.72 |
|
-.1*/ |
64.50 |
52.00 |
44.14 |
54.40 |
64.18 |
|
..»■'/. |
97.32 |
92.85 |
78.82 |
97.14 |
96.71 |
|
y.r'. |
0.07 |
.40 |
1.28 |
.91 |
0.42 |
|
*»V^' |
0 15 |
.84 |
2.69 |
1.91 |
0.90 |
|
. ,• ■*■ |
oii 4y |
100.09 |
99.39 |
100.97 |
99.95 |
I
0\ V««.'f I • ■
. . ...:aiii. \ ii;!iiiia. ♦ ... li.Jiin.'if ami Ohit) Railway, northeastern edge of Staunton,
.. ..J .' >liiii Sjuiii^rt, \ ir^iniu. ...." ;■,!.. ..-I 4if (iitH'ii villi*. Virginia.
/-^-. .;.;.'! M. V ii^riiiia.
,inj>;iiali\i*ly \n\iv Murat limestone is a succession , . ,. "h.tla possibly KOOO ftn-t in thickness. This is the
,M hull WiiM M) named by Professor Campbell because . . . . ,. ii«Mr Lfxinulon constructed on and of this rock. ..... iiaia niak(^ up the lower third of the formation.
',..- Imiihtoue occurs in the middle third, chang-
I...I. • .11 ibe toj)niost division. After long exposure , . i.!l« .iiid up|HT divisions appear shaly at the surface.
«t|-«i-Eil or VIRGINIA
i"i„\r»: XIV
;. 1. — Hou»e MountaiiiK, RiH-kbriiljit- iimnty, Vi*w Iriiiii Kk-h Hill. Imikhi); acTOM valley!) o( LilxTty Hall liiiivittune and hilla of Xutiirnl Ilriilgf Uni«- ■tone. Thp mountains arc i-apiied by the Massnniiltm quarltil* and the ^opM shnv the Martinsbiirp ahnW.
Fiff. 2.— t'uM ij> Ma~^aii IIOISK MIUNTAINS
11.^. f. & It. milr,.a.l. KaKl.- MoimlxiTi. (H.KKI) MASSANI TTKN SANDSTrWK.
104
MiNEUAL KESOUIKI-^ii OF VIKGIXIA.
In Central woritcrn Virginia, the Stones River rocks are practically absent. A few areas show a slight development, but as a source of cement material tlie formation may l>e neglected. The succeeding Miirat and Liberty Hall limestones eorresjwnd in a general way to the Chambersburg formation of the more northern parts of the Valley, although lithologi- cally, no trouble will be encountered in separating these different divisions.
The heavv thertv beds of the Xatural Bridge limestone are usually followed by a massive gray, coarsely crystal line pure limestone to which Professor Campbell has ap|)lied the name Murat from its occurrence along Buflfalo creek at Murat, Virginia. The limestone, as a whole, runs very liigh in calcium carbonate and, for this reason, it is the source of the lime burned at several points in central western Virginia. The lower portion often shows chert nodules upon weathering, and it was from this part that the samples in the following table giving a high silica content were obtained. About 125 feet of the Murat limestone are exposed at its type locality, but fn^quently the thickness is not so great.
Analyses of Murat limestone. (J. H. GibboDej, Analyst)
|
I l*er cent. |
II Percent. |
III Per cent. |
IV Percent. |
V Percent |
|
|
SiO, |
1.80 0.22 54.50 97.32 0.07 0.15 |
5.92 .48 52.00 92.85 .40 .84 |
11.72 6.16 44.14 78.82 1.28 2.69 |
1.58 .84 54.40 97.14 .91 1.91 |
1.62 |
|
FejOjand AljO,— CaO |
0.72 54.18 |
||||
|
OaCO, |
96.71 |
||||
|
MkO.' |
0.42 |
||||
|
MgCO, |
0.90 |
||||
|
ToUl.... |
99.49 |
100.09 |
99.39 |
100.97 |
99.95 |
I. Eagle Mountain. Vir;:inia.
II. Cut along HaltiiiKire and Ohio Railway, northeaatem edge of Staunton, Virginia.
III. Railroad cut. Mini Springfl. Virginia.
IV. 4 miles norllicMst of (Jreenville, Virginia. V. N>ar Lexington. Virginia.
Siiccrecling ihi> (M)in])}iralively pure Murat limestone is a succession cf more arg:illac'('<nis strata poKsibly 1,000 feet in thickness. This is the LilKM'tv Hall linicstoiH' which was .^n named by Professor Campbell because of tJK* oUl historic ruin near Lexington c()nstructed on and of this rock. Fine-grained dark blue strata make up llie lower third of the formation. I>ark<'r, more argillaceous limestone occurs in the middle tliird, chang- ing into calcareous <halos in the topmost division. After long exposure to the weather, the nuMdle and upiHM' divisions appear shaly at the surface.
MIM':iUI. KBSOI'RCKS OF VIURINIA.
Fig. 1. — HonH lIuunUhiM, KorkbridfiC cuuntj. View from Kich Hill, luuking BcroM valleys nf Liberty HhII linientone and bills of Natural Bridge lima- ■tone. The niountaina urc capped by tbe MamaQutteii quartxite and the slopes Bhon- the Mnrtinebiirg shale.
Vig. 2. — Fold in Musnanulteii Handstune, ('. A O. railriiad. Ka)[b- Mountain. HOUSE MOCN'TAIXS AND Fnl.DKD MASSAXfTTKS SAX1)ST0!JE.
CEMENT AND CEMENT MATERIALS.
105
Numerous brachiopods, trilobites and ostracods occur in the lowest beds, but the higher divisions are seldom fossiliferous. The general distribu- tion of both the Murat and Liberty Hall formations is indicated on the accompanying map, figure 17 (page 111). Analyses showing composition of the Liberty Hall formation are given below.
Analyses of Liberty Hall limestone.^ (J. H. Gibboney, Analyst)
I Per ct.
II Perct.
Ill Per ct.
IV Percl.
V Perct
VI Per ct.
VII Per ct.
VIII Perct
SO,.
AI A and Fe,0,
CaO
CaCO
MgO.'
MgCO,
Total
|
7.10 |
8.98 |
48.80 |
19.48 |
6.10 |
14.96 |
9.38 |
|
0.92 |
1.02 |
7.60 |
2.74 |
0.98 |
.94 |
1.02 |
|
51.10 |
47.12 |
22.46 |
42.16 |
51.02 |
46.54 |
49.56 |
|
91.25 |
84.14 |
40.11 |
75.29 |
91.11 |
83.11 |
88.50 |
|
0.46 |
2.80 |
0.10 |
.81 |
0.08 |
.12 |
.57 |
|
0.96 |
5.88 |
0.21 |
1.70 |
0.17 |
.26 |
1.21 |
|
100.23 |
100.02 |
96.72 |
99.21 |
98.36 |
99.26 |
100.11 |
12.64
1.82
46.86
83.66
.71
1.50
99.62
I. Compact black argi11aceou» limeHtone. Eagle Mountain, Va.
II. Gray compact limestone, Eagle Mountain. Va.
III. Dark siliceous limestone. Eagle Mountain, Va.
IV. Shaly limestone. Mt. Sidney, Va.
V. Coarsely crystalline limestone, Mt. Sidney. Va. VI and VII. Fine-grained, dark blue limestone. Staunton. Va. VIII. Subcrystalline limestone, eastern foothills. Little North Mountain, Augusta Co., Va.
DETAILS OF LOCALITIES IH NORTHWESTERN AND CENTRAL WESTERN
VIRGINIA.
Under this caption the writer wishes to discuss briefly only the more favorable localities in northwestern and central western Virginia showing good exposures of the pure and argillaceous limestones. It is to l)e under- stood, how^ever, that unless otherwise stated, all discussion of these rocks refer to their use in the manufacture of Portland cement. Analyses of rock from other localities than those discussed arc given, since a knowledge of the composition of the rock is most essential.
Winchester, — ^The geologic structure at Winchester and north to the state line is somewhat complicated by faulting, but two sources of cement material have been noted. These are: (1) a band of Stones River pure and dolomitic limestones passing through Winchester and thence northeast and southwest; (2) a strip of argillaceous limestone a short distance east
CEMENT AND CEMENT MATERIALS. 107
of this band. The Stones River strata here are especially characterized by the growth of cedar trees along their outcrop. The purer portion of this formation is made up of dove or bluish limestones often showing outlines of small gastropods upon worn surfaces. The argillaceous materials are very similar to those described later in the Strasburg section, and, as the analysis shows, have a favorable composition:
Analysis of argillaceous limestone, just east of Winchester, Va.
(J. H. Gibboney, Analyst)
Per cent.
Insoluble 14.78
Iron oxide (Fe,Oa) and alumina ( AlaO,) 2.72
Lime (CaO) 44.94
Calcium carbonate (GaCOs) 80.25
Magnesia (MgO) 0.34
Magnesium carbonate (MgCX3s) 0.71
Total 98.46
Middietown, — ^This and the neighboring towns of Stephens City and Meadow Mills are favorably located so far as transportation facilities and abundance of cement materials are concerned. The following section taken along the street west from the depot at Middletown gives the sequence of rocks in the region.
Section of Ordovician rocks in the vicinity of Middletown, Virginia.
Feet 9. Mainly covered but apparently all calcareous shale 100
5. Mainly covered but showing traces of earthy limestone 150
7. Partially covered, with bluish limestone at the top and earthy or nodular
limestone at intervals 100
6. Nodular limestone with specimens of Echinosphwrites near the base 20
5. Arenaceous shale 20
4. Unexposed 30
3. Dark gray to black limestone with chert 38
2. Massive dove limestone, apparently the same bed as that quarried for lime
at Strasburg 40
1. Mainly magnesian limestone but with a few layers of pure limestone 30O
This section then continues westward, the magnesian and pure lime- stones of the Stones River formation being shown in a small anticline between Middletown and ^Meadow Mills, until in the vicinity of the latter place, the higher pure and argillaceous limestones are again exposed in a small syncline.
Strasburg, — The abundant pure and clayey limestones in the vicinity of Strasburg combined with the railroad facilities, makes this one of the most promising sites for cement manufacture. As shown on the map,.
MINERAL HKSOl'iri'KS OF Vir
figure 16 (this pajrt'). tlio lino of outcrop of Martinsburg shales passw through Strasburg so that to the east of the town an ahundance of shale may be found, while fo the west occur the various limestones. The roeka of economic importance outcrop between the town and Strasburg Junction, a mile or more to the west, where the upper part of the Stones River
Ordovidan ebtlm
Fig 16 — Map showing distribution of cement materiaU of northwestern Virginia.
formation i- biiii.' i|iiarricd ami liurneil into liuic. The section printed • in ]iage 106 !■• fmmil esposieil mainly between the two localities mentioned^ iiltlinu^'li the lnw(r beds of the Stom's ltiv<T and the Natural Bridge iloloTriUcfi outcrop wi'sl of Strasliurg .hinition. The rocks dip to the oast and arc cTUOiintcroil in ascend inn order as Strasburg is approached.
CEMENT AXU CEMENT MATERIALS.
109
The Strasburg section is «o complete that it has been employed as a type section for northwestern Virginia. For this reason, the various strata likely to be employed as cement materials were carefully sampled and analyzed. The results of these analyses are given in the following table:
Analyses of limestones and shales, vicinity of Stnisburg, Virginln.
(J. H. Gibboney, Analyst)
1 : II
Per ct. i I'er ct.
Ill , IV
Per ct. I Per ct.
V I VI Perct. Perct.
Vll Pferct.
Inaoluble
Iron oxide ( Fe,Oj)
Alumina (Al^O,)
Lime(CaO)
Calcium carbonate (CaCO,)
Ma^eMia (MgO)
Magnesium carbonate (MgCO,)
ToUl
2.32 0.24
54.04
96.43
0.62
1.09
100.08
43.601 19.78
}
6.60' 1.88
26.80
47.86
1.04
2.18
99.04
12.10 1.48
41.601 47.40 74.28 84.64
0.39 0.82
99.76
0.80 1.68
99.90
8.68
1.32
49.68
88.71
0.64
1.34
100.06
12.00
2.26
47.16
84.21
0.64
1.13
99.60
27.60
8.36
37.40
66.97
0.68
1.22
99.16
I. Blue limestone, lower part of bed 3a, Chambersburp formation.
11. Siliceou.s blue liniefttone, upper part cf bed 3a. Chambersburp formation.
III. Dark gray, argillaceous limestone, bed 3e, Chambersburg formation.
IV'. Thin bedded dove limestone, bed 3f, Chambersburg formation.
V. Massive dovoi limestone, bed 3g, Chambersburg formation.
VI. Gray earthy limestone, bed 3i, of Chambersburg formation.
VII. Calcareous shales at base of Martinsburg shales.
Woodstock and vicinity. — About 350 feet of argillaceous limestones of the Chambersburg formation may be found exposed just east of Wood- stock before the Martinsburg shales are encountered. These limestones and the overlying shales dip at an angle of about 40° southeast. Practi- cally the same thickness of cement rock is exposed to the northeast and southwest of Woodstock, but although the outcrops are not as good as those noted in the Strasburg area, essentially the same section may be found. As this line of outcrops is paralleled by the Southern Railroad, which is at no place more than 2 miles distant, favorable sites for cement plants are offered. The most promising location, however, is in the immediate vicinity of Woodstock, since here the cement rocks outcrop on the western side of the Xorth Fork of the Shenandoah river. Farther south the river flows between the railroad and the cement rock outcrop, and the cost of a spur line would thus be greatly increased.
Pure limestones for mixture with the cement rock can be found in the immediate vicinity, west of the line of the outcrop of the argillaceous
110
MINERAL RESOUROES OF YIROINIA.
rock. Limestone strata, high in calcium carbonate and low in magnesia, were found interbedded with the dolomites west of Woodstock, and more extended search would no doubt reveal an ample supply. The following analyses are of the pure and argillaceous limestones in this vicinity:
Analyses of limestones, Woodstock, Virginia. (J. H. Gibboney, Analyst)
Insoluble
Iron oxide (Fe^Os) and alumina (Al^O,)
Lime (CaO)
Calcium carbonate (CaCOj)^
Magnesia (MgO)
Magnesium carbonate (MgCOj)
ToUl
Percent.
56.26
4.82
18.96
33.88
.91
1.91
96.87
II Per cent.
14.88
2.38
46.00
80.36
1.04
2.18
99.80
III Percent
10.04
1.46
48.48
86.67
0.73
1.64
99.61
I. Siliceous limestone, Stones River formation. II. Argillaceous limestone, upper part of Chambersburg formation. III. Dark blue limestone, lower part of Chambersburg formation.
Harrisoniurg and vicinity, — A syncline showing the argillaceous lime- stones and Martinsburg shales occurs just west of Harrisonburg and extends northeast-southwest for a distance of some miles. The cem«it rock is especially well shown along the street just west of the Southern Bailroad depot, but exposures of the shales and underlying argillaceous rocks may be seen along the country roads going northwest, west, and southwest from the town. The thickness of the argillaceous limestones in this vicinity could not be ascertained with certainty because of the lack of continuous exposures, but it probably does not fall short of 200 feet F'ossils indicating the Chamber«burg age of the strata were not uncommon in the rocks shown along the western edge of the town.
Purer limestone deposits are found in considerable quantity east and southeast of Harrisonburg. Exposures of this rock may be seen in a cut on the Chesapeake and Western Railroad just east of the crossing with the Southern Eailroad. Here a rather pure gray limestone occurs, having the composition shown in analysis No. I of the table on page 113.
From 75 to 100 feet of argillaceous limestones and calcareous slates are exposed in a cut on the Chesapeake and Western Bailroad southwest of Harrisonburg and just west of the Southern crossing. Samples from this cut were analyzed by Charles Catlett with the result shown in analysis No. XL
OEHENT AND CEMENT HATEEIAL6.
About 1.5 miles north of Harrisonburg the Southern Railroad passes through a cut about 20 feet high and 400 to 600 feet in length, exposing comparatively horizontal slaty Umeetone with a composition shown in analysis No. TV.
Vf".
if
ite^
OEMENT AND CEMENT MATERIALS.
113
Partial analyses of cement material in the vicinity of Harrisonburg,
Virginia.
(Charles Catlett, Analyst)
Insoluble
Iron oxide (Fe.0,) and alumina (AI^O,)
Magnesia (MgO) « ....
Lime (CaO)..
|
I |
n |
III |
|
Per cent |
Per cent |
Per cent. |
|
2.08 |
27.06 |
7.00 |
|
.60 |
8.32 |
.70 |
|
.60 |
1.42 |
2.36 |
|
64.24 1 |
86.79 |
49.00 |
IV Per cent
26.24 1.68 1.67
38.32
I. Pure gray limestone, cut on Chesapeake and Western Railroad just east of crossing with the Southern Railroad.
II. Calcareous slates, exposed in cut on Chesapeake and Western. Railroad just west of crossing with the Southern Railroad.
III. Dark, friable limestones, exposed at crossing of railroads just south of
HarrUonburg.
IV. Calcareous slates, cut along Southern Railroad 1.5 miles north of Harris-
onburg.
All of the localities so far discussed are west of Massanutten MouDtain and have good railroad facilities. East of this mountain the same lime- stone would normally occur, since the mountain itself is made up of a great downfold of strata or syncline. Here, however, the railroad facilities are not as good and moreover the pure and argillaceous limestones are often cut out by overthrust faulting. The best localities showing the complete geologic succession and with transportation facilities are at Wadesville and Riverton.
Wadesville, — The Middle Ordovician limestones exposed along the eastern edge of the Massanutten Mountain syncline are crossed by the rail- road at Wadesville. For a short distance north of this place, the line of out- crop is not far from the railroad, and to the south and west for 1.5 miles the two parallel each other, so that this locality affords an abundance of suitable limestones within short distances of transportation facilities. The black argillaceous limestones are especially well shown along the road just east and w«est from the railroad station. The following section was observed along this road on the farm of John M. Lock, starting about half a mile east of Wadesville and ending at Opequon creek on the west. The strata dip at an angle of about 40** northwestwardly.
114 MINERAL RESOUBOES OF VIRGINIA.
Geologic section, WadewUle, Virginia.
Feet
6. Martinsburg group, gray, black, and olive shales
4. Dark blue and black, compact, argillaceous limestone 400
3. Coarsely crystallice grayish blue limestone 70
2. Stones River formation: Gray, dolomitic limestone with intercalated pure dove-colored layers, base not observed. These Stones River limestones have much the same character described for the formation in other sec- tions of this part of Virginia. The only strata of economic importance are the intextsalated dove-colored pure limestones. The rock may be identified by its numerous ''birdseye" markings and by the presence of the ostracoda Leperditia fahulites. 1. Natural Bridge dolomite: Gray, dolomitic cherty limestone. These strata show comparatively few outcrops in this particular section but the presence of the rock can be detected by the more or less numerous chert fragments left upon weathering.
Beds 3 and 4 of the above section fonn the Chambersburg formation and are of the most importance in the present consideration, as they will be the sources of whatever rock may be used for Portland cement. Bed 3 is a massive, rather pure limestone with some of the layers crowded with the peculiar organism Strephochetus. The same strata occur at the base of the Chambersburg formation in the Strasburg section, figure 15 (see page 106), and, as analyses of that rock indicate, the lime content is high. These particular strata therefore, together with the dove limestone of the underlying Stones Eiver formation, can be relied on as a source of pure limestone for mixture with highly argillaceous rock. Bed 4 embraces the typical cement rock of Ordovician age and is a uniform, dark, compact argillaceous limestone. The lower portion is massive but the upper part is less 80 and weathers into a shaly rock. The latter may be distinguished from the succeeding Martinsburg shales, which it somewhat resembles when weathered, by the higher percentage of lime as well as by the fossil contents. As in other sections, the ball cystid Echinosphcerites is the characteristic fossil of this bed. At Wadesville specimens occur sparingly throughout the bed but are most numerous in the upper part.
Riverton and vicinity, — Three distinct bands of cement rock outcrop? are found at this place and in the immediate vicinity, on account of a fold in the Ordovician rocks east of the Massanutten Mountain syncline. As shown on the map, figure 16 (page 108), Riverton itself is built upon the Martinsburg shales which form the highest beds of thia more eastern syncline, but just to the east and to the west of it, the strata of the Chambersburg and Stones River formations may be seen. The latter formation is being extensively quarried at a locality just northeast of Riverton.
CEMENT AND CEMBNT MATERIALS. 115
Mount Sidney and vicinity. — From Staunton to Monnt Sidney and thence for several miles northeast, the Valley Branch of the Baltimore and Ohio Bailroad either closely parallels or cuts through the belt of argilla^ ceous limestone brought up on the western flank of the Massanutten Mountain syncline. The same rocks reappear on the eastern flank, 3 to 4 miles distant. The intervening country is occupied by Martinsburg shales, all of the younger rocks found on Massanutten Mountain having been removed by erosion. The favorable composition of the rock and the proximity of these two belts to railroads — the western to the Baltimore and Ohio, and the eastern to the Norfolk and Western — cause them to be worthy of attention. The following analysis of specimens from the eastern belt in the vicinity of Weyers Cave shows more magnesia than the average.
Analysis of argillaceous limestones near Weyers Cave, Virginia,
(Wirt Tassin, Analyst)
Per cent.
SiUca (SiO,) 14.62
Alumina (AlaOa) and iron oxide (FesOg) 6.00
Calcium carbonate (CaCO.) 67.92
Magnesium carbonate (MgCOs) 4.69
Water (H,0) 3.94
ToUl 98.07
The section exposed along the railroad at Mount Sidney is as follows :
Geologic section. Mount Sidney, Virginia.
Feet
6. Tjrpical Martinsburg shales
6. Calcareous shales and shaly limestone with few fossils 200+
4. Brown shalee with graptolites 60
3. Gray coarsely crystalline limestone yielding some chert upon weathering 70
2. Haavily bedded dark blue limestone lOO-j-
1. Ddomitic limestone
Staunton, — East and northeast of this city the argillaceous limestones are well developed, and, together with the shales and pure limestones near bv, offer abundant raw material for the manufacture of cement. The railroad facilities at Staunton are exceptionally good, for here a plant could obtain coal and ship its products over several lines. Ordinarily coal could be had on the most favorable terms over the Chesapeake and Ohio, but in times of labor disturbances in the New River field, the fuel supply could still be obtained from the Fairmont region. The purer limestones in the vicini*^y of Staunton, as a rule, run unusually high in lime, so that shales
116
ICINEBAL B£S0DRC£8 OF TIBaiMlA.
or clays for mixture vitb them will be neceBsary. Unlimited quantitiee of Bhale may be found in connectiou with the limeBtone, but deposits of good clays are not so common. In this region, the lover part of the shalea are unusually calcareous, as the following analyses will show, but hi^^er up in the seriea the percentage of lime is very small :
Haninaburg shale
and overljing
formationi
Fig. 20. — Map of rhe Vallej or VirginU frani SUuDton to Natural Bridge. Arcs marknJ by diagaaal broken lineB includee Matarat Bridge uid UDdenTing for-
CEMENT kSD CEMENT MATERIALS.
117
Analyses of Martinsburg shales and Liberty Hall limestone, vicinity of
Staunton, Virginia. (Charles Catlett, Analysl)
I PefcenU
II Per cent
III Per cent
IV Per cent
SiHca (KO,)
Alomina (A 1,0,,) and iron oxide (Fe,0,)
Lime (CaO)
MaipieMa (M^)
(krboD dioxide (00,)
|
19.28 |
19.92 |
23.08 |
|
9.86 |
10.76 |
10.08 |
|
36.42 |
87.05 |
85.89 |
|
1.08 |
1.72 |
.94 |
|
31.70 |
||
10.28
4.86
45.79
.79
32.80
I to III. Calcareous shales showing variation in composition. rV. Liberty Hall limestone.
The Ordovician section in the vicinity of Staunton is best seen along the Baltimore and Ohio Bailroad tracks and the road beyond the ice factory on the northeastern side of the city. Here it will be noted that the r^on is much folded and faulted but through the aid of several sections, the following succession can be determined :
Feet
Geologic section, Staunton, Virginia.
4. Martinsburg shale. Brown and yellow shales, calcareous at base
3. Liberty Hall limestone. Fine-grained, argillaceous, unfossiliferous lime- stone 325-h
2. Murat limestone. Gray, coarsely crystalline limestone crowded with
Solenopora and bryozoa 100
1. Natural Bridge limestone. Gray dolomite strata with a few layers of
purer limestones
All of the above formations of the Staunton section furnish cement materials but the most important and abundant rock is to be had from the Liberty Hall limestone. Analyses of the various divisions are given below.
The Cambrian dolomitic limestone forming the lower part of the Natural Bridge formation grade upward imperceptibly into another series of strata having essentially the same composition but differing in that extensive layers of chert are interbedded with the usual dolomites. The area occupied by this division may usually be recognized by their topo- graphic features, for the chert gives rise to conspicuous hills or ridges. Chestnut Ridge, Sugar Loaf and Betsy Bell are examples of this topog- raphy in the vicinity of Staunton. The age of this portion, whicli is especially well exposed about Staunton, has been determined as Beek- mantown from the gastropod and cephalopod remains found at various points in the Valley, but particularly in the vicinity of Lexington, Virginia.
"\
I
\
..1
OBMENT AND CEMENT MATERIALS.
119
Analyses of Liberty Hall limestone, vicinity of Staunton, Virginia.
(J. H. Gibboney, Analyst)
Percent
II Percent
Imoluble
Orgmnic matter.
Iron oxide (Fe,0,) and alomina (AlsO,)
Lime(CaO)
Galcinm carbonate (CaCXDg)
Magnesia (MgO)....
Magnenum carbonate (MgOOs)
Totol
9.38
.24
1.02
49.56
88.60
.67
1.21
100.36
Analyses prepared by Mr. Catlett from samples of the lower part of the Martinsburg shales have been given on a previous page. These indicate that this division of the shales in the vicinity of Staunton agrees with the same horizon elsewhere in chemical composition, the high amount of lime being the noteworthy feature. The higher members of the shales in the region east of Staunton show the same lithologic and other char- acters described for central western Virginia in general.
Western edge of Valley, north of 8ta/unton. — The outcrops of the Ordovician limestone along the western edge of this part of the Valley are in general so remote from railroads that, in spite of the excellent rock shown at a few places, exploitation of this region is at present useless. Furthermore, throughout a considerable portion of this region the argil- laceous limestones are cut out by overthrust faulting, the magnesian lime- stone resting upon the shales of still higher formations. But a single area can be mentioned in which the cement rocks are exposed within a reasonable distance of a railroad. Several miles north of Stokesville, the terminus of the Chesapeake and Western Railroad, and a few miles K>uth of Little North Mountain, good outcrops of the rock are encountered. The quantity and quality of these limestones are such that, with the railroad facilities so near at hand, the rock will undoubtedly prove of economic importance. Shales are at hand for mixture with the cement rock when its percentage of lime is too high, while pure limestones, to increase the percentage when necessary, are found in sufficient quantity in the Valley just to the east. Indeed, even with the present facilities, this is one of the most promising cement localities in the Valley.
F'ig. 1. — OverthniBt fault in Tuscanira sandstone, near Panther Gap, Vir^nia. Figr. 2. — Fields of residual decay in Shenandoah Valley, near Natural Bridge, Virginia.
MIN'KKAI. RESMriKl')
Fig. 2.— Sum.' Hi Ki^-. I. NATURAL BRIDGK T.IMKSTOKK, VIRGINIA.
OEHENT AND CEMENT MATERIALS. 121
limMtone in this eastern area of outcrop^ are overturned to the west so fhat the strata show a fairly uniform eastward dip. This folding like- wise causes the rocks to have apparently a great thickness, but a careful examination will show the repetition of similar beds in regular order. In addition, the core of an anticline or syncline may be occasionally observed, and whenever it is possible to get a continuous section, a maximum thick- ness not exceeding that given by Professor Campbell is found. This close folding also involves the underlying Murat limestone, but because of the few and relatively unimportant exposures of this formation at the surface, it has been differentiated on the map only along the western border of the Ijexington area where its outcrops are of most importance.
The general features of the geologic section at Lexington have been pointed out by Professor Campbell, but the following more detailed section is offered to show the variation in these strata :
Geologic section, Lexington, Virginia, and vicinity.
Feet in. Black Biver limestone including Liberty Hall, Murat, and underlying fonnmtioos. 8. liberty Hall formation:
(d) More or less thin bedded argillaceous limestone and calcareous
shales 600^
(e) Fine-grained, dark, massive argillaceous limestone with an
obscure conchoidal fracture 250 ±
(b) Argillaceous knotty limestone with many fossils, brachiopods and trilobites particularly numerous. Ampyx and Agnostus
characteristic fossils *. 40
(a) Crystalline and eubcrystalline limestone full of bryozoa,
sponges, etc. Often absent from sections 10
2. Murat formation:
Massive gray crystalline limestone weathering into a red, clayey
soil oomparatiyely free from chert 100
1. Massive, somewhat cherty limestone, seldom ehown and of slight
thickness. Fossils nuiiierous
IL Stones Biver limestone.
Massive dove limestone. Seldom present in the section and thick- ness slijifht when present
I. Natural Bridge lime^^tone.
Gray and light blue magnesian limestone weathering into chert.
Conspicuous beds of chert near the top
Of the different divisions distinguished in the section, the Liberty Hall and Murat are the only formations worthy of consideration as a source of cement materials, the former as a cement rock itself, and the latter as a more or less pnre limestone which could be used in mixture.
Mr. Charles Catlett has analyzed a series of samples from the Lex- ington strata, but the particular strata from which they were derived was
122
MINERAL RESOURCES OF VIRQINIA.
not noted. In all probability, No. I of the subjoined table was from the Murat limestone, while Xos. II and VI represent various phases of the Liberty Hall beds.
Analyses of limestones from Lexington, Virginia.
(Charles Catlett Analyst)
I
Percent.
II Percent.
Ill Percent.
IV
Percent.
V
Percent.
VI Percent
8ilica(SiO,)
Alamina ( A1,0„ ) and iron oxide ( Fe^O, )
Lime(CkO)
Maenesia (MffCO)
Carbon dioxide ( CO,)
|
0.73 |
9.31 |
11.86 |
12.92 |
17.42 |
|
.79 |
3.47 |
1.76 |
8.88 |
4.70 |
|
68.71 |
46.30 |
46.64 |
45.14 |
42.44 |
|
.83 |
.88 |
.74 |
1.87 |
1.68 |
|
38.82 |
37.20 |
35.62 |
||
22.60 7.06
36.72 1.69
82.52
The analyses presented in the following tabic were made from sample? selected by the writer:
Analyses of Murat and Liberty Hall limestones, vicinity of Lexington,
Virginia.
(J. H. Gibbonej, Analyst)
Insoluble
Iron oxide (Fe|0,) and alamina
(AlA)
Lime(CaO)
Calcium carbonate (CaCO,)
Magnesia (MgO)
Magnesium carbonate (MgCO,)...
ToUl.
Per cent.
1.62
0.72
54.18
96.71
0.42
0.90
99.95
II Percent.
4.32
.76 52.06 92.96
.94 1.97
100.01
III Percent.
10.24
0.74
48.16
86.00
1.00
2.10
99.08
IV
Percent.
1.30
0.54
54.28
96.98
0.86
0.76
99.58
I. Compact white limestone, Murat formation, Reservoir Hill, Lexington. Vir- ginia.
II. Subcrystalline limestone, base of Liberty Hall beds, near Lexington, Virginia.
III. Dark argillaceous limestone, Liberty Hall fonnation. Spring Cave Hill, Lex-
ington, Virginia.
IV. Compact gray limestone, Liberty Hall formation. Spring Cave Hill, Lexing-
ton, Virginia.
The analyses given below indicate the composition of the rocks in other parts of central western Virginia :
i
■i
MINKKAl. KKKUrKCKS 111' VIKIitNIA.
I'l-ATB XVII.
|
1^ |
|
|
'^ ■'■*'""-^ |
^-'•v, k |
|
^I^^I |
,^3c' |
|
^^^si |
■rtiv ' ■ . ' |
lie. iiciir ShcnviKJi]. XHtiiral Dridge >itnttiiii LOWER CAMUKI.W fjlAltrZITK AXn siikiiwood j-ormation.
CEMENT AND CEMENT MATERIALS.
1-23
Anaigses of limestones and shale, central western Virginia,
(J. H. Gibboney, Analyst)
Per cent
■ • •
24.12
S.22
Iiiiolabla.
Orguiie matter
Inm oxide {FmSKi \
Alomina (AlA) i
lime (CW) i 40.24
CUdmB eartmiate (OaOO,) ' 71.86
.05 .10
MagDeria (MgO).
Magneeiom oarbooate ( MgOO,).
ToCaL:.
98.80
II Per c^nt
30.24
4.56
83.00
58.98
2.72
5.81
99.54
III Per cent
17.86 .14
1.60
41.84
78.62
8.08
6.88
{
99.60
IV Per cent.
28.60 1.82 2.33 2.53 35.08 62.64 1.14 2.39
99.81
L Murmt formation, near Rockbridge Baths, Virginia. IL Compact siliceous limestone, Li^rty Hall formation, Kerrs creek, Virginia.
III. Argillaoeoiui limestone, upper part of Liberty Hall formation, 5 miles west
of Rockbridge Baths, Virginia.
IV. Hiflfaly calcareous shales, basal beds of Martinsburg group, 2 miles west of
Rockbridge Baths, Virginia.
OEOLOOT OF SOITTHWBSTERH VIROIHIA.
In the discussion of northwestern and of central western Virginia, the writer has indicated no great differences in the stratigraphic succession or the lithology of the Ordovician strata in various parts of the Valley. In southwestern Virginia, however, a new factor in the study of these same strata is introduced. Ordinarily rocks deposited synchronously in comparatively small areas show no great differences either in lithological aspect or in their fossil contents. In the division of the State now to be discussed the Ordovician strata, particularly, differ in various areas in both of these respects. For example, the eastern portion of the Oreat Valley shows a development of Ordovician limestones and shales totally different from that found in the westernmost part of the State. In the stady of the various sections, these differences in strata of apparently the same age were encountered in traverses made across the Valley and ridges to Ae west, while little difficulty was experienced in correlating the rocks in directions paralleling the length of the Valley.
Major Faults.
When compared with the two divisions discussed previously, the geology of sonHiweBtem Virginia is complicated by grent folds and overthrust faults. The region is traversed in a northeast-southwest direction by at
124 MINERAL RES0UB0E8 OF VIRGINIA.
least 7 major faults and a number of minor breaks. The easternmost jf these major faults passes along the base of the Holston and Iron mountains, where a sandstone of Lower Cambrian age is faulted against the dolomitic limestones. Sandstone^ shale, and impure limestone outcrop east of this fault, but on account of their unsuitable chemical composition are not considered here.
The 6 major faults west of this eastern break have been described and named by Professors Lesley and Stevenson in the articles mentioned in the bibliography (page 166). These are, in order going westward, (1) the Walker Mountain, (2) Saltville, (3) Copper Creek, (4) Hunter Valley, (5) Wallen Valley, and (6) Poor Valley faults. These 7 major faults divide southwestern Virginia into 6 rather narrow areas, in each of which a belt of Ordovician limestones and shales is usually exposed. The general distribution of the cement^making materials in these areas is indicated on the maps of southwestern Virginia (pages 143 and 147). The relation of these faults to one another and the arrangement of the strata in each of the areas is shown in the accompanying structure section, figure 23.
Oeneral Distribution of Cambrian and Ordovician Strata.
The study of numerous sections including the Ordovician rocks in this part of the State brought out the fact, as mentioned before, that similar successions of these strata are at present exposed in long narrow areas bounded by the major faults. The differences of sedimentation in these various areas may perhaps most readily be shown by an outline of the stratigraphic succession in each. In both cases the well known Knox dolomite serves as a basal datum line and the identification of the various formations rests upon their fossil contents as well as their litho- logic characters.
In the easternmost area, namely the region between the Blue Bidge and the Walker Mountain fault, or the Bristol area of the accompanying table, the following succession of Ordovician rocks may be observed:
3. Thin bedded sandstones and sandy shales (Tellico). 2. Blue to black calcareous and sandy shales (Athens). 1. Knox dolomite.
Ix)cally, a thin, somewhat raagnesian, blue limestone, the equivalent of the Lenoir limestone of eastern Tennessee, occurs between the Knox anH the Athens.
The narrow strip between the Walker Mountain fault and the Salt- ville fault, the Walker Mountain area of the table, shows an overlapping
|
r * If |
/ |
|
f |
|
|
1 |
§ |
|
I i |
|
|
fWV |
^ |
|
/ |
^ |
|
-i |
|
|
*M. |
..-^ " |
|
< |
^ |
|
VIP^ I |
^ |
|
-V "^ |
|
|
tf /-s |
|
|
'*J'W-W |
^^ |
|
.^L |
\-te |
ill
»■! =
lilt
5 ► •58 "-5
c 3 «M
126 MINERAL RESOURCES OF VIRGINIA.
of the formations of the next western band upon sediments of the one just described. This section, which is most clearly shown along the rail- road from Glade Spring to Saltville, is as follows :
7. Red sandy shales and thin bedded sandstone (Bays).
6. Yellow and dark colored shales with thin bedded blue limestone at base (Sevier).
5. Red calcareous shales and impure red limestone (Moccasin).
4. Beds of marble with calcareous shales (Holston).
3. Blue and black calcareous shales (Athens).
2. Thick bedded, ff^Jt slightly magnesian limestone (Lenoir).
1. Knox dolomite.
Beds of marble belonging to the Holston formation immediately follow the Knox dolomite in the Clinch Mountain area, namely the region between the Saltville and Copper Creek faults. Here, with the exception that the Lenoir limestone and Athens shale are wanting, the section, a^ shown below, is essentially the same as the preceding one:
6. Heavily bedded white quartzite and sandstone (Clindi).
5. Red sandy shales and thin bedded sandstone (Bays).
4. Yellow and dark colored shales with thin bedded blue limestone at the base
(Sevier).
3. Red calcareous shales and impure red limestone (Moccasin).
2. Marble at base followed by thin bedded limestones and shales (Holston). 1. Knox dolomite.
The marbles of the Holston formation are particularly well developed in Tennessee. In Virginia, the northernmost occurrence of the fauna asso- ciated with these marbles was noted at the foot of Clinch mountain, south of Tazewell.
The strip bounded by the Copper Creek and Hunter Valley faults, here called the Copper Creek area, contains the Knox dolomite, the Moccasin, Sevier, Bays, and Clinch formations, but in place of the marbles and thin-bedded limestones of the Holston, heavily-bedded, gray and dark blue limestone is found. The difference between this and the Holston formation may be seen in cuts along the Virginia and Southwestern Railroad, near Speer Ferry and Clincliport. The exact equivalents of this massive limestone have not yet been determined, but, the new name, Pearis- burg limestone, is here instituted.
The westernmost and most different sequence of the Ordovician in Virginia is found in the valley of Powell river, where the arrangement of the rocks, with the exception of the Clinch sandstone, is exactly the same as that obtaining in southwestern Ohio, central Kentucky, and central Tennessee. In Virginia, these rocks are known to occur through- out the Powell river vallev eastward to the Wallen Vallev fault, and in
CEMENT AND CEMENT MATERIALS. 127
all probability the narrow strip between this fault and that of Hunter valley is also occupied by them. The formational names employed below for the rocks in this area are, with the exception noted before^ those used in the Ohio Valley Ordovician:
10. Heavy bedded white quartzite or sandstone (Clinch).
0. Red and yellow limestones and shales (Lorraine). 8. Yellow arenaceous shales and limestones (Eden). 7. Olive and yellow^ shales (Utica).
6. Thin bedded blue limestones and blue or vellow shales (Trenton-Cathey).
5. Dark blue crystalline limestone (Trenton-Bigby).
4. Yellow and olive shales (Trenton-Hermitage).
3. Thin bedded dove limestones and yellow shales (Tyrone).
2. Massive dove limestone (Stones River).
1. Knox dolomite.
On account of the variation of the rocks in these diflferent areas, the importance, from an economic standpoint, of delimiting their boundaries, is apparent. In the maps accompanying this article, it has been possible to show only the general areas of outcrop of the purer Ordovician lime- stones and of their associated strata.
The theories for this distribution of strata in separate areas need not be entered npon here more than to state that TJlrich and Schuchert, in their Paleozoic Seas and Barriers, have advanced the apparently well founded idea that the area of the Appalachian Valley during Ordovician times was divided longitudinally into several narrow troughs which were more or less effectively separated from each other; and that the observed differences in sedimentation and life characterizing the several troughs arc attributable to this separation.
The general relation of the Cambrian and Ordovician formations and the more important cement rock horizons are indicated in the following correlation table:
128
MINERAL RESOURCES OF VIRGINIA.
Cambrian and Ordovician formations of southwest Virginia.
|
General time scale |
Bristol area |
Walker Mt. area |
Clinch Mt area |
Copper Creek area |
Powell Val- ley area |
|
Cincinnatian (Upper Ordovician) |
Clinch Bays Sevier* |
Clinch Bays Sevier* |
Clinch Bays Sevier* |
Lorraine Eden Utica* |
|
|
Mohawk ian (Middle Ordovician) |
Tellico Athens* Lenoir (often absent)* |
Moccasin Holston* Athens* Lenoir* |
Moccasin Holston* |
Moccasin Pearisburg* |
Trenton* Tyrone* Stones Rivei* |
|
Canadian (Lower Ordovician) saratogan (Upper Cambrian) |
• Knox |
Knox |
Knox |
Knox |
Elnox |
|
Acadian (Middle Cambrian) |
Nolichnckj Honaker |
Nolichucky Honaker |
Nolichucky ( Mary ville • Kogersville ( Butledge |
Nolichucky Mary ville Rogersville Butledge |
|
|
Georgian (Middle Cambrian) |
Russell |
Bnasell |
BoRsell |
BittseU |
'Horizons of cement materials.
Stratigraphy.
Instead of considering each of these areas of depoflition separately, it seems best in the present connection, because of lack of space, to give a short description of the various formations, and to present the analyses in tabular form. The geographic distribution of the formations and the assignment of each analysis to its proper place in the section, must, there- fore, be left to the reader.
Cambrian Formations.
Russell shales. — The oldest strata outcropping in soutliwestem Vir- ginia northwest of Holston Mountain, are sandy shales, thin-bedded sand- stones, and brown argillaceous shales, found in the valleys of Copper creek and Clinch river. The sandy beds make up the greater part of this formation, and therefore, as a whole, the Russell shales are of little value from an economic standpoint. Argillaceous shales occur somewhat sparingly in the upper third and might prove of value for a mixture with pure limestones in the manufacture of cement. The great range in the chemical composition of these shales is indicated in the following analyses:
CEMENT AND CEMENT MATERIALS.
129
Analyses of Russell shales, vicinity of Clinchport, Virginia,
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide {Fefit), alumina (AljOs)..
Lime (CaO)
Calcium carbonate (CaCOi)
Magnesia (MgO)
Magnesium carbonate (MgCOi)
I Per cent.
Total.
41.72 5.68
17.32
30.93 9.17
19.29
97.62
II Per cent.
89.52 7.22 0.40 0.72 1.05 2.21
99.67
I. Brown argillaceous shales, upper part of formation. II. Sandy shaleB, several hundred feet from top of formation.
Ruiledge limestone. — Impure magnesian limestones 200 to 300 feet in thickness follow the Sussell shales. Their composition varies con- siderably but the magnesia content appears too high in all the samples examined to make the rocks of use.
Analyses of Ruiledge limestones, vicinity of Clinchport, Virginia,
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide (Fe,0|), alumina (Al/)a)..
Lime (CaO)
Calcium carbonate (CaCOi)
Magnesia (MgO )
Magnesium carbonate (MgCOa)
Total
II Per cent.
2.58 1.12 30.80 55.00 19.70 41.37
100.07
I. Gray limestone near base of formation. II. Dark limestone near top of formation.
RogersvUle shale, — Separating the impure Eutledge limestone from the purer limestone of the succeeding formation — the Maryville limestone — is a blue calcareous shale named from Rogersville, Tennessee. This shale is abundantly fossiliferous and contains a fauna of Middle Cambrian age. The shale persists as such over a large area in northeastern Tennessee, but in southwestern Virginia it disappears from a shale formation toward the east. Along the western side of the Valley the formation often changes to a dark, siliceous limestone which cannot be separated from the under- lying Rutledge limestone.
130
MINERAL RESOURCES OF VIRGINIA.
Analyses of Rogersville shale, vicinity of Clinchport, Virginia.
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide (Fe,Os), alumina (Al,Oa)..
Lime (CaO)
Calcium carbonate (CaCOi)
Magnesia (MgO)
Magnesium caii^nate (MgCOa)
Total
Per cent.
31.22 6.20 21.41 38.23 10.90 22.89
98.54
II Per cent.
87.48 1.32 3.60 6.42 1.76 3.70
98.92
I. Calcareous shales, upper part of formation. II. Sandy shales, lower part of formation.
MaryvUle limestone. — Of all the Cambrian formations, this is the most promising from an economic standpoint, because it is a comparatively pure limestone which, in a combination with associated shales, might make a good cement rock mixture. Wherever these strata occur as a well defined formation, they are heavily bedded, blue limestones^ varying in thickness from 500 to 650 feet. The type locality is at Maryville, Blount county, Tennessee, but typical exposures are found in southwestern Virginia northwest of a line following Moccasin Bidge.
Analyses of Maryville limestone, vicinity of Clinchport, Virginia.
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide (FcjOj), alumina (AlaOj)
Lime (CaO)
Calcium carbonate (CaCOj)
Magnesia (MgO)
Magnesium carbonate (MgCO,)
Total
|
I |
II |
III |
|
Per cent. |
Per cent |
Per cent. |
|
35.06 |
31.78 |
10.54 |
|
1.90 |
1.84 |
0.64 |
|
29.16 |
35.78 |
46.74 |
|
52.07 |
63.89 |
83.43 |
|
5.33 |
0.93 |
1.82 |
|
11.20 |
1.96 |
8.82 |
|
100.23 |
99.47 |
98.43 |
I and II. Cherty black limestone.
III. Blue crystalline limestone.
IV. Grayish, subcrystalline limestone.
IV Per cent.
2.16 0.54 50.80 89.43 3.79 7.96
100.08
OEMEKT AND CEMENT MATEBIALS. 131
IlonaJcer limestone, — Southeast of a line paralleling Moccasin Eidge, the Maryyille limestone, the Sogersville shale, and the Butledge lime- stone, cannot be distinguished as separate formations but form a lithological unit for which the name Honaker limestone is employed, because of good exposures at Honaker, Eussell county, Virginia. This formation is of blue and gray limestone with a maximum thickness of 1,400 feet. It seems worthy of exploration only as a source of natural cement rock.
Nolichucky shale. — This formation, the second shale horizon of economic importance, overlies the Honaker limestone in the Valley proper but follows the Maryyille limestone west of Moccasin Bidge. The shale deriyes its name from the Nolichucky river in Tennessee and carries a fauna of Middle Cambrian age. As a whole, the formation is composed of calcareous shale and shaly limestone reaching a maximum of 400 feet in thickness. West of Copper Bidge tiie Nolichucky shale is greatest in thickness, but eastward it diminishes until just east of Bristol it disappears altogether. At a few localities in this portion of Virginia, the Nolichucky shales contain limestone lentils of considerable thickness, which, with the associated shales, furnish the necessary raw material for cement manu- facture. The most important of such occurrences is in Carter Valley, where a lentil of blue limestone with a maximum thickness of 550 feet is found.
Analysis of Nolichucky shale, vicinity of Clinchport, Virginia,
(J. H. Gibboney, Analyst)
Per cent.
Insoluble 38.68
Iron oxide ( FejO,) , alumina ( Al,Oi) 5.28
Lime (CaO) 29.46
Calcium carbonate (CaCO.) 62.61
Magnesia (MgO) 0.80
Magnesium carbonate (MgOO,) 1.69
Totol 98.26
Cambro-Ordovician.
Knox dolomite. — Succeeding the Nolichucky shale is the great lime- stone formation of the Valley — ^the Knox dolomite. In southwest Vir- ginia this formation varies from 2,000 to 3,000 feet in thickness, a con- siderable diminution from the 4,000 feet exposed in the typical localities in Knox county, Tennessee. The Knox is generally a heavily-bedded gray magnesian limestone or dolomite with comparatively few natural outcrops. The line of outcrop is usually indicated by the heavy mantle of residual chert. These cherts occur in the limestone as nodular, dense
132
MINERAL RESOURCES OF YIRQINIA.
masses of a white color, although often they appear as a porous sandstone. At some places the top of the formation is marked by a white argilla- ceous limestone which, if developed in sufficient quantity, and easily accessible, would prove of value economically. The reference of thia limestone to the Knox is doubtful and the exact position of these strata cannot be determined until more paleontological evidence is at hand.
The Kjiox dolomite is one of the sources of the ridges of southwefctorn Virginia, but only when its strata are inclined at a considerable angle- In tho process of weathering, the soluble dolomite is washed away, leaving the insoluble chert to maintain the ridge. In this area the most promi- nent of such ridges are Copper and Moccasin Ridges, Walker Mountain, and Chestnut Ridge.
Tlie lower part of the formation is generally unfossiliferous, but from evidence found elsewhere in the Valley, this portion is of Upper Cambrian age. The cherts in the upper part of the Knox dolomite are sometimes fossiliferous and contain a fauna of Beekmantown age. As this fauna has been found 1,000 feet below the top of the Knox, the Beekmantown portion has a thickness of at least that amount.
Considered as a source of cement material, the Knox is of little, if any, importance.
Analyses of Knox dolomite, (J. H. Gibboney, Analyst)
Insohible
Iron oxide (FejO,), alumina(A],0,).
Lime(CaO)
Calcium carbonate (CaCO,)
Magnesia ( MgO )
Magnesium carbonate (MgCO,) . . . .
Total
|
II |
III |
IV |
V |
|
Pr. cent. |
Pr. cent. |
Pr. cent |
Pr. cent. |
|
3.98 |
3.62 |
1.40 |
40.44 |
|
1.12 |
0.48 |
0.08 |
4.00 |
|
44.88 |
37.90 |
31.48 |
16.90 |
|
80.14 |
67.<58 |
56.22 |
30.18 |
|
6.43 |
13.50 |
20.29 |
11.42 |
|
13.52 |
28.35 |
1 42.61 100.31 |
23.98 |
|
98.76 |
100.13 |
98.60 |
VI Pr. cent
1.3S 2.88 52.48 93.71 0.67 1.41
99.38
Insoluble
Iron oxide (Fe,0|), alumina ( Al,Os).
Lime (UO)
Oalcinm^ carbonate (CkOO,)
Magnesia (MgO)
Magnodnm oarixmate (MgOOy) ...-
Total -
|
VII |
VIII |
IX |
X |
XI |
|
Pr. cent |
Pr. cent. 9.60 |
Pr. cent. 7.56 |
Pr. cent |
Pr. cent. |
|
24.54 |
8.09 |
34.62 |
||
|
3.66 |
0.40 |
0.98 |
1.52 |
4.72 |
|
39.20 |
50.60 |
30.10 |
46.64 |
31.72 |
|
70.00 |
90.35 |
68.75 |
83.28 |
56.64 |
|
0.62 |
4.29 |
18.00 |
3.18 |
1.26 |
|
1.31 |
9.00 |
37.80 |
6.68 |
2.64 |
|
99.51 |
110.35 |
105 09 |
99.57 |
98.62 |
XII Pr. cent.
12.34 2.34
39.60
70.72 6.22
13.06
98.46
OEMENT AND CEMENT MATERIALS. 133
L Purer limestone Beam from thick bedded strata (Upper Cambrian), lower
portion of formation, 2 miles south of Saltville, Virginia. IL Dolomitic limestone (Beekmantown), middle portion of formation, 4 miles south of Saltville, Virginia, in. Dolomitic limestone (Beelmiantown), upper part of formation, 4 miles south
of Saltville, Virginia. IV. Knox dolomite, Lyon Gap section (Bed 1), Smyth county. V. Knox dolomite, Lyon Gap section (Bed 2), Smyth county. VL Dove-colored purer limestone, near Goodwin Ferry, Gilea county. VII. Arenaceous limestone, 800 feet below top of formation, near Goodwin Fstrry,
Giles county. Vni. Bluish-gray limestone, lower part of formation, vicinity of Clinchport, Vir- ginia. IX. Gray dolomite limestone, upper part of formation, vicinity of Clinchport,
Virginia. X. Less dolomitic layer in upper part of formation, vicinity of Clinchport, Vir- ginia. XI and XII. White argillaceous limestone, top of formation, Speer Ferry, Vir- ginia.
OrdoYioian Formations.
The most promising sources of supply for cement materials in this part of Virginia, as elsewhere in the Appalachian Valley, are of Middle Ordoyician age. On account of the variation in the Ordovician formations noted before, various names have been applied to the several lithologic units. These names, as well as the sequence of formations in tbi different areas of outcrop, have been indicated in the table on page 128, where a name hitherto most commonly applied to the purer Ordovician limestones of the southern Appalachians has been omitted. Explanations regard- ing this formation, the Chickamauga limestone, are therefore in order.
Chickamauga limestone. — The Ordovician limestone exposed in the westernmost outcrops of the Appalachians show a considerable thickness when compared with limestones of the same age farther east. To this thick limestone formation the name Chickamauga was ap- plied and has been employed on the maps of many of the Valley folios. The separation and delimitation of this purer limestone from the great underlying dolomitic series was a distinct advance in mapping, and the name was snbsequently employed for any or all of the purer Ordovician limestones following the Ejiox dolomite. As mapping proceeded, eastward and northward from the typical area, other Ordovician formations were distinguished. In these cases the term Chickamauga was restricted to the pore limestone immediately following the Knox dolomite. Thus while its lower boundary was thought to be constant, the upper wa9 regarded as
Taziable.
At fhe typical Chickamauga outcrops along Chickamauga creek, in QwrptL, and east of Chattanooga, Tennessee, this limestone appears to
134
MINERAL RESOURCES OF VIRGINIA.
contain representatives of most of the geological formations of the general time scale between the top of the Knox dolomite and the base of the Silu- rian. With this explanation in mind, a glance at the table of geologic formations will indicate that in the type locality the Chickamanga in- cludes representatives of not only the Ordovician limestone, but also of the succeeding shales and sandstones of Virginia localities. In the eastern part of the Appalachian Valley the term was applied to the strata to which Safford long before gave the name Lenoir limestone; farther west, the Holston marbles and limestones have been mapped as the Ghickamauga, while in Powell Biver Valley, the generally quite distinct or different Stones River, Black River, and Trenton strata have been grouped under the same name.
Lenoir limestone, — A gray, slightly magnesian limestone usually mapped as the Ghickamauga succeeds the Knox dolomite in the more eastern por- tions of the Valley in Virginia and Tennessee. To this, Safiford and Kille- brew applied the above name from its occurrence at Lenoir, Tennessee. In Virginia a maximum of 200 feet is reached in the Glade Spring region, but the usual thickness is much less than this amount. The Lenoir lime- stone is of particular interest paleontologically on account of its typical Chazy fauna.
Analyses of Lenoir limestone.
(J. H. Gibboney, Analyst)
I Per cent.
Insoluble 4.(>0
Iron oxide (FcaO,) , alumina ( AlaOs) .24
Lime (CaO) 51.90
Calcium carbonate (CaCO.) 02.68
Magnesia (MgO) • 1 .06
Magnesium carbonate (MgCOt) | 2. 32
Total 99 84
|
II |
III |
|
Per cent. |
Per cent |
|
7 34 |
16.12 |
|
0 88 |
3.20 |
|
48.04 |
42.74 |
|
85.78 |
76.32 |
|
3 07 |
1.34 |
|
6 45 |
2.82 |
|
100.45 |
98 46 |
I and II. Slightly magnesian limestones, 4 miles south of Saltville, Virginia. III. Argillaceous limestone, Lyon Gap section. (Bed 3), Smyth county.
Athens shale. — ^Resting either upon the Lenoir limestone, or, when this 18 absent, upon the Enox dolomite, are dark and blue calcareous shales named from Athens, M cMinn county, Tennessee, where they are well de- veloped. In Virginia, these shales attain a maximum thickness of 1.000 or IjSOO feet The lower strata are black carbonaceous shales passing into
OEMENT AND CEMENT MATERIALS.
135
blue calcareous shales, which, as the top of the formation is approached, become more and more sandy. In folio No. 59 of the TT. S. (Jeological Sur- vey, the more important Athens shale areas of Virginia are shown. The composition of all the samples selected for analysis is given below. These analyses, which are of only the lower and middle divisions, indicate the value of this shale as a cement material.
Analyses of Athens shale.
(J. H. Qibbonej, Analyst)
Insolable.
Organic matter
Iron oxide (Fe^O,) alnmina
(AlA)
Lime(CaO)
Calcium carbonate (CaCO,). .
Magnesia ( MgO)
Magnenium carbonate( MgCO,)
I Perct.
19.48 1.2«
1.28
42.20
75.36
1.16
2.46
ToUl 99.85
II Perct
11.24 .60
.96 48.62 86.82 Trace Trace
99.62
III Perct
5.82
0.64
47.32
84.50
4.16
8.74
99.60
IV Perct
17.64 .08
1.40
43.84
78.28
1.26
2.64
100.04
V
Perct
11.40 .82
1.38
47.14
84.18
.95
2.00
99.78
VI
Perct
25.80
3.74
37.96
67.36
0.12
0.24
97.14
VII Per ct.
17.58
2.44> 43.44 77.69
0.04
o.oa
97.69
I. Calcareous shale, 2 miles south of Abingdon, Virginia. II. Shalj limestone, 3 miles east of Bristol, Virginia. III. Limestone band, 4 miles east of Bristol, Virginia. IV and V. Dark shales about 5 miles south of Saltville, Virginia. VI. Dark shales (Bed 4), Lyon Gap section, Smyth county. VII. Dark blue shales (Bed 4), Lyon Gap section, Smyth county.
Holsion formation. — The Ordovician limestone mapped by the U. S. Geological Survey in the vicinity of Knoxville, Tennessee, as the Chicka- mauga, contains beds of marble in its upper part, distinguished as the Holston marble. These marbles and thin shale beds accompanying them, hold a fauna of bryozoa, crinoids, cystids, and sponges so different from other Ordovician formations that this Holston division or its equivalent can easily be recognized elsewhere. In some parts of Virginia and Tennessee, these shales and marbles immediately follow the Knox dolomite; elsewhere they rest upon the Lenoir limestone or its equivalent, as at Knoxville, Tennessee; again, in more eastern belts where the marble is comparatively thin, either the Athens shales or both the Athens and Lenoir may inter- vene. Therefore in view of the characteristic lithology, the peculiar fauna, and the fact that it occupies a definite position in the stratigraphic column, the name Holston is herein accorded the rank of a fonnational name.
136
HIKBRAL RESOURCES OF TIBOINIA.
The Holston fonnation is probably best developed along the nortl em edge of Clinch MouDtain in both Tennessee and Virginia. At '. Hill, west of Morristown, Tennessee, the variouB strata making u formation are well exposed, and this pnction us well as any other aloi same line of outcrop, may be taken as typical for the Holston. In i west Virginia, a good section may be observed at almost any point be Speer Ferry and Gate City. The railroad cuttings and the natun poBures about Speer Ferry show the following succession of rocks:
Geologic sectum, Speer Ferry, Tirginia.
5. Clinch Bandstone. Co&ne, white, niasbiTe quartzit« and randBtone, out-
cropping at crest of Glineh Mount.iin
6. Bays i&ndstone. Red sandy shales and sandstone containing numeroua
Lorraine fossils
4. Sevier shales. Yellow or blue shales, calcareous in lower part especially 8. Moccasin limestone. Red argillnraoua limestone with a few drab-«olDr«d
2. Holston (ormation. Marble, limestone and shales in the following order:
(d) Yellow shales irith thin argillaceous blue or dove limestone break- ing up into nodular masses upon weathering
(c) Blue and graj coarsely crystalline limestone, masaiTe when un- weathered but splitting up into layers 2 to 4 inchea in tliickneM when exposed
(b) Blue, drab, and yellow shales with numerous fossils
{a] Pink and gray marbles with coarsely crystalline limestone
1. Knox dolomite:
(b) White, flne-grained argillaceous limestone (Knoxl)
(a) Cray, magnesian, cherty limestone
Although the Holston formation contains a variety of diverse i still all of them are low enough in magnesia to be considered as o materials.
Analt/ses of Holston marble and shale. (J. H. Gibboney, Analyat)
I
Inaoluble. - 23. M
lion oxide (Pe,0,), alumina (AljO,'
Lime(CaO)
Calcium cubonate <CbCO,)
Hagn«iiB<MgO)
Magnesium carbonate (HgCO,)
11
HI IV I
VI
Total ...
|
Per ct. j Per et 'pr. ct |
Pr. ct |
Pr.ct |
p,.«.i |
|
23.64 '. 0.S6 .39. &2 |
3.180 |
10.60 10.10 i |
|
|
3.62 I l.IO 5.64 |
4.36 |
3.24 |
2.36 |
|
39.86 ; 66.00 28.44 |
36 14 |
48 06 |
19.70 |
|
71.18 : 98.21 60.70 |
59.18 |
96.82 |
16.72 |
|
0.88 1 0.08 i 0.R8 |
«,«« |
0 70 |
0.21 |
|
1.78 0.17 , 1.86 1 1.38 |
1.43 |
||
|
100.02 1 100.34 .97.71 |
98.72 |
100.06 |
98.62 |
OEMENT AND CEMENT MATERIALS.
137
Insoluble
Iron oxide (Fe,0,), alumina ( AljO,)
Lime (CaO)
Calcium carbonate (CaCO,)
Magnesia (MgO)
Magnesium carbonate (MgCO,)
Total
|
VIII |
IX |
X |
|
Per ct. |
Perct |
Pr. ct. |
|
8.16 |
4.66 |
12.18 |
|
1.24 |
1.46 |
0.98 |
|
49.76 |
61.50 |
47.56 |
|
88.86 |
91.96 |
84.93 |
|
0.76 |
0.61 |
0.75 |
|
1.68 |
1.06 |
1.68 |
|
99.84 |
99.14 |
99.67 |
XI Pr. ct.
14.96
1.70
46.08
80.50
0.38
0.81
XII Pr.ct
8.26 1.82 50.40 90.89 0.12 0.26
97.97 101.23
XIII Pr.ct
8.42 3.66 47. 1» 84.14 0.67 1.41
97.68
I. Calcareous shale interbedded with Holston marble, 5 miles south of Salt-
ville, Virginia. II. Light-color^, coarsely crystalline marble, base of formation, Speer Ferry, Virginia.
III. Blue shale, succeeding marble, in lower part of formation, Speer Ferry,
Virginia.
IV. Drab ehales, middle portion of formation, Speer Ferry, Virginia.
V. Bluish argillaceous limestone, upper part of formation, Speer Ferry, Virginia.
VI. Dark argillaceous limestone, upper part of formation, Speer Ferry, Virginia.
VII. Heavily bedded argillaceous limestone, 3 miles north of Mendota, Virginia.
VIII. Dove limestone, 3 miles north of Mendota, Virginia.
IX. Thin bedded argillaceous and crystalline limestone (Bed 6), Lyon Gap
section, Smyth county, Virginia. X. Blue argillaceous limestone (Bed 6), Lyon Gap section, Smyth county,
Virginia. XI. Gray argillaceous limestone (Bed 6), Lyon €kip seetion, Smyth county,
Virginia. XII. Dark argillaceous limestone. Gate City, Virginia. XIII. Blue argillaceous limestone, Gate City, Virginia.
Pearisburg limestone. — In the table of formations on page 128, the Pearisbnrg has been indicated as a formation between the Knox dolomite end the Moccasin limestone in the Copper creek area of southwestern Vir- ginia. This is a new fonnational name introduced for the limestones occupjdng this interval, and particularly for the rocks at Pearisburg, Qiles county, where the following type section for the formation is exposed.
Oeologic section, Pearisburg, Virginia.
Feet
4. Sevier shales
3. Moccasin limestone. Purple calcareous shales and argillaceous limestones
with seams of impure aove limestone 200
2. Pearielmrff limesUme:
(f ) lAffit gray compact limestone with gastropods abundant in the lower
beds and numerous ostracoda in the upper part W
(•) Fine-grained dove limestone 20
(d) Imbeoded magnesian limestone 25
(e) Li|^t to dark gray moderately fine-grained limestone in lower part
and masfire oberty beds in upper division 65
)o HINEBAL BESOUECES OF VIsaiMIA.
(b) Dark bluiBh-gray limestone, Buhcryatalline or earth;- in the upper part and alightly chertj in the lower beds. A Qtrvanetla lees than
0.6 inch in diameter very abundant SO
(a) Dark gray mottled massive limestone leaving a deep red chert upoi weathering. Fossils numeroua, bryozoa, braebiopods, and Solmtopora
being particularly abundant 250
Knox dolomite. Magnesias limestone weathering into reddish chert
Analyses of Pearishurg limestone, vicinity of Pearisbvrg, Virginia. (J. H. Oibboney, Analyst)
1
II
III
' Pr. ct. Pr. et.| Pr. ct. Pr. cL Pr. ct. Pr,
IV
VI
vn
Inioluble 6.14,
Organic mailer
Iron oiide (Fe,0,), alumina (A1,U,] ..
Lime (CaO) 60.30
Calcium carbonate (CaCO,) 89.82
Magnesia (MgO) 1.57
Hagneuum oarbonale (MgCO,) 3 "
TolaL...
..100.'
.00, 1.00 48.00 51.36 85.72 91.71
52.00 92.84 1.43 3.00
2.16, O.dS
O.ee' 0.38
50.30, 51. S4
e0.82| 91.50
3.62' 3.66
7.60 7.68
100.24100.08
XII
Pr.ct.iPr.cLlPr.ct
XIV Pr.cL
Inioliible
Iron oiide {Fe,0,'),"il,iuiaVna (aV,6,').''
Lime (CaO)
Calcium carbonate (CaCO,)
Magnesia ( MgO)
Haguesium carbon ste (MgCOi)..
Tot«d. ..
100.09
6.64 6.04
0.80 n.S4
60. SO 61.80
90.71 91. 4S
1.04 0.80
3. 18 1.S7
O.IO U.S3
98.00 0.18
100.8
0.« 54.84
ar.tt
0.11
o.»
|
XV Pr.et. |
XVI Pr.ot. |
XVI 1 Pr. ci. |
-i Villi XIX XX Pr. cl-'pr. ct.iPr. ct |
XXI Pr.cL |
|
|
Insoluble Organic mattet Iron oiide (Fe,0,), alumina (AJ.O,) ■ |
3.26 0.34 |
1.17 0.26 1.20 |
2.12 !25 9f..0S 2^40 |
1.35 5.60J 1.50 !43' 0.78 0.68 1 51.40 64.70 06.04| 91. SO 97.78 0.72 0,15 1.7S 1.52 0.31 |
2.3" 0.60 54.0A |
|
Calcium carbonate (CaCo,) Magnesia MgOl |
94.46 91.88 0.H9] 2.05j 5.52 |
Bfl,54 0.30 CM |
|||
|
ToUl |
100.11 99.99 |
09,98 |
99.97 99.70100.17 |
1011,08 |
CEMENT AND CEMENT MATERIALS.
139
I. Dark gray limestone (Bed 2a), Pcarisburg, Virginia. II. Dark blue limestone weathering into chert (Bed 2a), Pearisburg, Virginia.
III. Subcrystalline limestone (Bed 2b), Pearisburg, Virginia.
IV. Lig^t gray, massive limestone (Bed 2c), Pearisburg, Virginia. V. Dark, massive limestone (Bed 2c), Pearisburg, Virginia.
VI and VII. Laminar, unfossiliferous limestone (Bed 2d), Pearisburg, Virginia. Vin. Fine-grained dove limestone (Bod 2e), Pearisburg, Virginia. IX. Semi-mottled limestone (Bed 2f), Pearisburg, Virginia. X. Coarsely crystalline gray limestone, near Qoodwin Ferry, Virginia. XI. Compact, dark argillaceous limestone, near Goodwin Ferry, Virginia. XII. Dark, argillaceous limestone, near Goodwin Ferry, Virginia.
XIII. Dark, compact limestone, near Goodwin Ferry, Virginia.
XIV. Crystalline limestone, near Goodwin Ferry, Virginia. XV. Dove limestone, near Goodwin Ferry, Virginia.
XVI, XVII, XVIII. Massive limestone from lower part of formation, Ripplemead, Virginia. Dr. Henry Froehling, analyst.
XIX. Compact, massive limestone, lower part of formation, vicinity of Narrows, Virginia. XX. Thin ^ded blue limestone, middle portion of formation, vicinity of Nar- rows, Virginia.
XXI. Dove-colored compact limestone, upper part of formation, vicinity of Nar- rows, Virginia.
Analyses of Pearisburg limestone, vicinity of Tazewell, Virginia.
(J. H. Gibboney, Analyst)
Insoluble ■
Iroo oxide (Fe,0,), alumina (A1,0,).
Linie(CaO)
Caldam carbonate (CaCO,)
Magnema (MgO)
Magoesiom carbonate ( MgCO,)
Total
|
I |
II |
III |
IV |
V |
VI |
|
Per ct. 2.04 |
Per ct. 1.80 |
Per ct. 5.36 |
Per ct. 2.82 |
Per ct. |
Per cL |
|
5.94 |
6.04 |
||||
|
0.50 |
1.00 |
0.72 |
0.78 |
1.46 |
1.14 |
|
53.80 |
63.24 |
51.32 |
53.90 |
61.34 |
61 . 20 |
|
96.07 |
95.42 |
91.64 |
96.25 |
91.68 |
91.42 |
|
1.33 |
0.43 |
0.67 |
0.51 |
0.33 |
0.43 |
|
2.78 |
0.91 |
1.40 |
1.06 |
0.70 |
0.91 |
|
101.39 |
99.13 |
99.12 |
100.91 |
9y.78 |
99.51 |
VII Per ct
4.66 1.84 49.14 87.76 2.09 4.40
98.56
I. Massive, finely crystalline limestone, base of formation, Tazewell, Virginia.
n. Blue, coarsely crystalline limestone, base of formation, Tazewell, Virginia.
III. Thin bedded dove limestone, middle portion of formation, Tazewell, Virginia.
IV. Massive dove limestone, top of formation, Tazewell, Virginia. V. Granular blue limestone. Five Oaks, Virginia.
VI. Thin bedded shaly limestone. Five Oaks, Virginia.
VII. Dove limestone. Five Oaks, Virginia.
Moccasin limestone, — East of the Powell river valley the various Middle Ordovician limestones are followed by an argillaceous red limestone named as above from its occurrence along Moccasin creek in Scott county. Along Clinch Mountain in both Virginia and Tennessee, the best develop- ment of this impure limestone occurs, with an average thickness of 500 feet The following table gives analyses of samples from various points in Bonthwestem Virginia, which indicate a rather uniform composition for the rock.
140
MINERAL UESOUUCES OF VIRGINIA.
Analyses of Moccasin limestone.
(.1. H. <.Tiblx>iU'y, AiuilvHt)
II
I,
Pr. ct Pr. c't
III Pr. <'t
IV Pr. vt
V
VI VII \^II IX
X
Pr. ct Pr. ot l*r. ct Pr. ft Pr. ct Pr. rt
Iron oxidf (Ke3(>3),{iliiinii)a ( AlgO^) l.isi
liirne (('«(>) 40. ;«
Calcium «irlx>iiat«.' ((;«(■( >3i 7J.04
MapD(>slii (MifO) O.sl
MaKDt'siumeurlMinaU' (MjrCT^Ja) 1.74
S.2S 24.7J. l:l.JO I1.7H 7.66
1.72 ;{.»4i J.W 1.4S .K2
;iS.4'*i 40.40 47.7>< 60.;{S
««.71 HI. 07 85.:t> «».96
0.rt4j 0.K7. .24 .35
l.:ttl l.tv'll ./W .76
4H.:W
s«.2r
•>••
o.w
2.02
Total JiS..>4
100.-2.">
-fli
W.72 iW.76 W.ll; «».20
I I
6.90: ai.iS. .'^.24 1.24! 4.96; 4.oO
uO.lO 31.J!W :».«'.
8SI.48 56.92 60.61 0.75 0.68' 0.25 1.67; 1.44. 0.5:1
W.lft ir7.60 JC.JU
I
28.88
4.40
•Hj.96
64.26
0.55
1.17
06.60
I. Argillaceous limestone about 5 miles south of Saltville, Virginia.
II. Impure drab limestone. Tazewell county, Virginia.
III. Impure red limestone. Five Oaks, Virginia.
IV. Dove-colored, argillaceous limestone, Five Oaks, Virginia. V. Granular blue limestone, Five Oaks, Virginia.
VI. Red clayey limestone, Pearisburg, Virginia.
VII. Red limestone, near Goodwin Ferry, Virginia.
VIII. Red shales, vicinity of Speer Ferry, Virginia.
IX. Red shaly limestone. Gate City, Virginia.
X. Red shaly limestone, 3 miles n«»rth of ^Icndota, Virginia.
Sevier shales. — In Sevier coTinty, Tennessee, the Tellico sandstone is followed by a great shale formation of Middle and Upper Ordovician age. Although fossils are rare in these shales, sufficient evidence has been found to indicate that the strata are of Trenton, XJtica, and Eden age. The Sevier shales are, therefore, apparently only a southern extension of the Martinsburg shales of more northern localities. The lithological features of the Sevier are also quite similar to the Martinsburg, so that a detailed description is unnecessary. The lower strata are of calcareous shale and interbedded limestone, the middle portion is more argillaceous, while the upper beds are quite sandy. The lower and middle portions, therefore, are of value as a source of cement rock. All the various horizons of the Sevier are represented in the table of analyses below, but most of the samples were obtained from the more important lower portion.
Analyses of Sevier limestones and shales.
(J. H. Gibboney, Analyst)
Insolable.
Iron oxide (Fe,Oa), alumina (A]«0^)
lime (CaO)..
Galdom oarbonate (OtOO^)
Magnesia (MgO)
Magneunm oarbonate (MgOC^)
•■■•••
Xotai ••••••••••■■••■•■•••■••••«• ■• •■■■••
|
I |
II |
III |
IV |
1 V |
|
Perct |
Perct |
Perct |
Perct |
Perct |
|
4.74 |
29.90 |
11.68 |
20.48 |
22.50 |
|
1.72 |
/ 2.02 \ 1.30 |
1.52 |
2.04 |
2.34 |
|
51.92 |
36.80 |
48.08 |
42.76 |
41.84 |
|
92.71 |
66.72 |
85.86 |
76.36 |
73.82 |
|
0.13 |
.58 |
0.45 |
0.51 |
0.05 |
|
0.27 |
1.28 |
0.94 |
1.06 |
0.11 |
|
99.44 |
100.17 |
100.00 |
99.94 |
98.77 |
VI
8.14
1.24
50.54
90.25
0.28
0.58
100.21
OEMENT AND CEMENT MATEBIALS.
141
Insoluble
Iron oxide (Fe,Os), ftlnmina (A1,0,)
Lime (CaO)
Caldom carbonate (CaCOs)
Magnesia (MgO)
Ma^esimn carbonate (MgCO,)
Total..
|
VII |
VIII |
IX |
X |
XI |
|
Per ct |
Per ct. |
Per ct. |
Per ct |
Per ct. |
|
28.62 |
73.00 |
29.70 |
6.12 |
41.48 |
|
3.76 |
11.28 |
3.18 |
2.92 |
6.04 |
|
36.42 |
6.76 |
36.16 |
61.16 |
28.00 |
|
66.03 |
12.07 |
64.57 |
91.39 |
60.00 |
|
0.99 |
0.04 |
0.60 |
0.25 |
0.30 |
|
2.08 |
0.09 |
1.26 |
0.53 |
0.64 |
|
99.49 |
96.44 |
98.71 |
99.96 |
98.16 |
XII Per ct.
71.88 8.56 8.64
16.26 1.27 2.68
98.37
Insoluble
Iron oxide (Fe,0,), alamina ( A1,0,)
Lime (CaO) „
Oalciam carbonate (CkCO,)
Magnesia (MgO) -
Magnesium carbonate (MgCO,)
ToUl
|
XIII |
XIV |
XV |
XVI |
XVII |
|
Per ct |
Per ct |
Per ct |
Per ct. |
Per ct |
|
7.08 |
33.40 |
55.60 |
23.48 |
56.66 |
|
1.88 |
4.92 |
7.60 |
3.86 |
8.37 |
|
60.60 |
32.86 |
18.20 |
39.44 |
18.41 |
|
90.36 |
58.68 |
32.50 |
70.63 |
32.88 |
|
0.41 |
0.18 |
0.61 |
0.09 |
0.72 |
|
0.87 |
0.38 |
1.29 |
0.18 |
1.61 |
|
100.19 |
97.38 |
96.99 |
98.05 |
98.31 |
xvm
Per ct
39.20
6.80
29.20
62.16
0.07
0.15
97.31
I.
II.
in.
IV.
Limestone band, lower part of formation, about 6 miles south of Saltville,
Virginia. Calcareous shales, lower part of formation, about 6 miles south of Salt-
ville, Virginia. Compact, black limestone, Trenton horizon, Tazewell, Virginia. Calcareous shales, Trenton horizon, Tazewell, Vir^nia. V. Compact argillaceous layers, lower part of formation, Five Oaks, Virginia. VI. Limestone bands, lower part of formation. Five Oaks, Virginia. VII. Caleareoufl shales at base of formation. Five Oaks, Virginia. Vni. Sandy shales, upper part of formation. Five Oaks, Virginia. IX. Calcareous shales, northern part of Wythe county, Virginia. X. Thin bedded blue limestone, lower part of formation (Trenton), near
Goodwin Ferry, Virginia. XI. Calcareous shales, near Goodwin Ferry, Virginia. XII. Sandy shales from Eden horizon, near Goodwin Ferry, Virginia. XIII. Thin bedded black limestone, Trenton horizon, Speer Ferry, Virginia. XTV. Calcareous shales, Trenton horizon, Speer Ferry, Virginia. XV. S«ndy dudea, Eden horinm, Speer Ferry, Virginia. XVL Cftleareous shales, basal portion of formation. Gate City, Virginia. XVn. Upper part of formation, Gate City, Virginia. XVin. CaleueouB shale, 3 miles north of Mendota, Virginia.
Bays sandstone, — ^In the Bays mountains of Tennessee^ the Sevier duQes are overlain by red sandy shales grading upward into red sandstones which have been mapped as a separate formation. This, the Bays sand- stone^ oontains fossilB of Lorraine age and is one of the more widespread fiirmationa in bo& Tennessee and Virginia. Its outcrops are generally near the smmnits of the Valley ridges, but the strata are usually concealed by Mra from the lormationB above.
142 MINERAL RESOURCES OF VIRGINIA.
Analysis of Bays sandstone, near Glade Spring, Virginia.
(J. H. Gibboney, Analyst)
Per cent.
Insoluble 90.18
Iron oxide (FeaOs) , alumina ( AlgOj) 5.72
Lime (CaO) 0.64
Calcium carbonate (CaCOa) 1.14
Magnesia (MgO) 0.03
Magnesium carbonate (MgCO,) 0.07
Total 97.11
Clinch sandstone, — All the more prominent Valley ridges owe their existence to this heavy sandstone. Tlie Clinch is a massive, coarse, white sandstone or quartzite 200 to 300 feet thick, and is prominently displayed along Clinch Mountain, the most conspicuous of the Valley ridges. The sandy nature of both the Clinch and the underlying Bays prevent their use as cement materials.
Details of Localities.
Although a variety of cement rocks outcrop in southwestern Virginia, the railroad facilities are such that the strata are accessible at compara- tively few points. In the present article, only the more important areas in counties with transportation facilities, are mentioned, leaving a detailed account to a more extended work upon the subject.
Giles County. — The portion of Giles county occupied by Ordovician strata is so large when compared with most other counties of southwestern Virginia, that a special map based ujmn a manuscript map by Mr. M. R. Campbell, is introduced. As indicated on this map, there are four impor- tant areas of these limestones and shales, and, further, each area is either crossed by or is within short distance of a railroad. The cement materials occur in the Pearisburg limestone and the lower portion of the Sevier shales. Analyses and a detailed section of the Pearisburg limestone in this area are given on pages 137-138.
Tazewell Cotmty. — This county has the advantage over many others in Virginia in having large outcrops of cement-making materials in close proximity to a railroad. Between the stations of Cedar Bluff and Tiptop, through the valley of Clinch river, the Norfolk and Western Railroad paaaes over Fearisburg limestone for almost the entire distance. A second li«!> of outcrop of the same rock is found southeast of Paint Mountain, a third occurs about Morris Knob and extends northeastward, while a fourth may be found along the foothills of Clinch Mountain. Of these, the first is of most importaace on account of railroad facilities, and the analyses
144 MINERAL RESOURCES OF VIRGINIA.
are mainly from samples collected along this strip. All the analyses of Pearisburg limestone from Tazewell county are assembled in the table on page 139.
Sections showing the structural geology and a detailed map of the general geology of the greater part of the county are given in the Tazewell folio of the XJ. S. Geological Survey. The succession and average thick- ness of the Ordovician rocks in this county are^ in ascending order, a»
follows :
Average thickness in feet
6. Clinch sandstone 200
5. Bays sandstone 300
4. Sevier shale 1,200
3. Moccasin limestone 300
2. Pearisburg limestone 900
1. Knox dolomite (upper part) 1,200+
Numerous exposures showing the purer and argillaceous limestones may be found in the vicinity of Tazewell, but continuous sections exhibit- ing all the subdivisions are not so common. The following detailed section of the Pearisburg limestone may be observed along the road following Plum creek, just north of Thompson valley, abont 4 miles southwest of Tazewell, Virginia.
Geologic section, just north of Thompson Valley, Virginia.
III. Moccasin limestone: Feet
Red and drab impure argillaceous limestone
II. Pearisburg limestone:
6. Thin bedded, mottled, dove limestone with red and drab shales in
the lower part. Fossils numerous 130
5. Drab shales with bands of thin blue limestone crowded with crinoid
stems 30
4. Thin bedded dove limestone with rather numerous fossils 00
3. Heavy bedded dark blue impure and argillaceous limestone 120
2. Shaly mottled limestone with few fossils 160
I. Coarsely crystalline crinoidal limestone, yielding some chert upon
weathering 180
I. Knox dolomite:
Heavily bedded magnesian limestone
Washington County. — In this county, the outcrops of Ordovician lime- stones and calcareous shales are found in two areas separated in a general way by Walker Mountain. In each of these areas the geological succession is somewhat different. East of Walker Mountain the dolomitic limestones of Cambrian and Ordovician age are succeeded usually by a bine to black Galcazeoofl and aandy ahale formation, which, in the Bristol folio of the U* 8. Gedlogical Siirvej^ haa been mapped as the Athens shale. The main
Ik;
146 MINERAL RESOURCES OF VIRGINIA.
outcrops of these shales, which here are from 1,000 to 1,200 feet in thick- ness, occur east of Bristol and Abingdon. As the more eastern parts of the Valley are approached, the Athens shales become more sandy and cannot be regarded as a possible source of cement material.
West of Walker Mountain only a few and generally unimportant areas are occupied by Ordovician rocks. This region is also without railroad facilities.
Smyth County. — The Walker Mountain fault passes through Smyth county along a southwest-northeast line, dividing it into southeastern and northwestern portions of nearly equal dimensions. This fault traverseB the western part of the Valley of Virginia and brings the Knox dolomite or older limestones in contact with the Carboniferous gypsiferous shales. East of this fault line, the strata arc limestones or shales generally unsuited for cement material. The important cement rocks are Ordovician lime- stones and shales outcropping along the western foothills of Walker Moun- tain. With the exception of the vicinity of Saltville, this strip is every- where at such distance from railroads that the material cannot at present be considered of much value other than for local use. In the valley west of Walker Mountain the Knox dolomite and underlying Cambrian lime- stone are exposed, but proceeding westward, these strata are found to be faulted against the Carboniferous gypsiferous shales similar to the fault- ing east of the mountain. This second fault is well shown at Saltville and has received its name from that town. The Cambro-Ordovician section exposed between these two faults is essentially the same throughout the county and therefore only a single section is given.
The following section is exposed along the road through Lyon Gap, northeast of Glade Spring, Virginia, starting at the cross roads near Mc- Henry creek, west of the Gap. The section concludes with the Clinch sand- stone forming the crest of Walker Mountain.
Geologic section, Lyon Oap, Virginia.
Feet
11. Clinch sandstone. White quartzite and sandstone
10. Bays sandstone. Yellow and red sandy shales and sandstones with
arenaceous limestone in lower portion 300
9. Sevier (Eden) shale. Yellow enales with thin arenaceous limestone
layers 1,000
8. Sevier (Trenton and Utica) shale. Brown to yellow shales 600
7. Moocaain limestone. Purplish shales and impure reddish limestone 400
4. HolsioD limestone. Blue and gray argillaceous limestone 50^^
5. Holsten limestone. Thin bedded argillaceous and crystalline limestones IOC
4. Athens shale. Dark blue calcareous shales 400
5. Lenoir limestooe. Compact dark argillaceous and magnesian limestone 200 SL Knox dolomite. Compact gray clayey limestone weathering into shales 30 1, Kaoz dolomite. Magnesian limestone weathering into chert
OSMSNT AMD CEMENT UATEBIALS.
148 MINERAL RES0UKCE8 OF VIRGINIA.
Scott and Russell Counties. — Geologically, these two counties are so similar that in order to ?ave repetition, they are treated together.
On account of faulting, two strips of Ordovician strata traverse both counties. The first line of outcrops is along the western slope of Clinch Mountain, and the second occurs^ similarly just west of Moccasin Ridge. The eastern line of outcrops terms a portion of the section bounded on the east by the Saltville fault traversijig-the western part of Washington count}'. The geologic section conlmenceson the east with Carboniferous rocks and continues westward -exposing* the various formations in descending order until in the vicinity of Copper creek, the Cambrian limestones are found thrust upon Ordovician rocks.
The geologic structure and character of the limestone of economic im- portance in these counties are well shown along the Virginia and South- western Railroad between Clinchport and Gate City. As this railroad cuts across both of the strips of Ordovician strata mentioned above, the section of the rocks along this line is given below. Starting with the Russell shales exposed just north of Clinchport, and proceeding south, the sacceeding Cambrian and Ordovician strata are seen until the Copper Creek fault is encountered, with the Pearisburg limestone and the Russell shales in con- tact. The sections then continue southward without interruption to Clinch Mountain, capped by the Clinch sandstone. As this section illustrates the general structure and sequence of rocks in both Scott and Russell counties, samples for analysis were taken from most of the formations.
Geologic section, exposed along the railroad, Clinchport, Virginia, south to
Clinch Moun tain .
(Thickness approximate) Feet
1. Russell shales (exposed just south of Clinchport). Sandy shales and
sandstones with brown shales at top
2. Rutledge limestone (exposed at Clinchport). Impure mottled lime-
stones; thin streaks of dove limestone alternating with impure black bands 200
3. Rogersville shales. Blue to brown calcareous shale 100
4. Maryville limestone. Massive gray limestone, lower part crystalline,
upper part dove with bands of dolomite 000
5. Nolichucky shale. Brovni to yellow calcareous and arenaceous shale. . . 600
6. Knox dolomite. Gray magnesian limestone, sandy in the middle part
and eherty toward the top 2,100
7. Pearisburg limestone. Heavily bedded crystalline and argillaceous dank
blue limestone. Fault
8. Russell shales.
9. Rutledge limestone.
10. Rogersville shale.
11. Maryville limestone.
12. NoUehudky ihmle.
\ ■.
• • / - .
;•»
HINKtIAI. IlKSor
liATK NVIIt.
Fig. 2. — Quariy in Lewistuwn limestODe. Lonitdkll!, BUEINA VISTA SHALES AUD LBWISIOWtf'
CEMEXT AXD CEMENT MATERlAl^. 149
13. Knox dolomite. Beds S to 13 have eaM&ually ihr ?^nnie litholo^- and
thickne9« a> beds 1 to C* rcspeinively.
14. Holiton fomuitiaiL Hiin bedded blue limestone and yellow shalen with
lenses of red marble toward the base 1 .i>00
15. Ifoccaain limestone. Bed argillaceous lime^tono .'tOO
Itt. Scrier shale. Yellow and blue calcareous shales 1 .5(X>
17. Bays sandstone — —
18. Clinch sandstone —
Lee County, — Tiro horizons in I>ee countr furnish raw uiatorial suit- able for cement manufacture. The first and more important of these occu- piei fhe intenral betreen the Knox dolomite and the Clinch sandstone, the aeoond is the Hancock limestone of Silurian age. On account of greater extent and more accessibility, the Ordovioian limestones are bv far of greater importance and are therefore discussed more in detail. The Han- eock limestone outcrops generally in small patches along the fault lines and la often cat out altogether. When well exposed it is seen to be a blue lime- atone high in lime but becoming cherty toward the top. The maximum ♦hMpM^ff* in the Powell Valley region was found to be 275 feet.
In this coimtj. the Ordovician rocks of value for cement purposes occur in two well defined areas. The less important of these is a strip brought up by the Wallen Valley fault and following the western slope of Powell Mountain along which these limestones and shales outcrop at a number of places. Although these rocks occur in quantity and usually hare the proper chemical constitution of cement material, the distance of their outcrops from the railroad and their otherwise gi»neral inaccessibility, cause them to be, at present, of little economic importance.
The second and more important area is bounded in a general way by Wallen Bidge and Cumberland Mountain, thus embracing the valley of Powell river. This valley in I^ee county shows numerous outcrops of afaales and pure and argillaceous limestouts of Ordovician age along its edges, the central portion being occupied mainly by the Knox dolomite. Along fhe northern edge of the eastern half of the Valley, the dove lime- stones immediately succeeding the Knox dolomite are faulted against De- Tonian black shale, all the inteneniufr fomiations being thus cut out. In the western half along the same side, faulting becomes less and less until fioally the full sequence of strata may be observed. All along the southern edge, however, the succession of rocks seem? to be normal so that the full development of Ordovician limestones and shales! may Ive found. The central portion of the valley occupied by the Knox dolomite averages several miles in width, but between this strip and Wallen l^idge is an area of Ordovician shales and limestones of equal widtli.
150 MINERAL RESOURCES OF VIRGINIA.
In Powell valley, the strata are of such composition that cement ma- terials of some nature may be obtained from almost any part of the rocks occurring between the top of the Knox and the base of the Bays sandstone, a thickness of at least 2,500 feet. The general geologic section of the Ordovician rocks of Powell valley is therefore quite different in the nature of its sediments from the rest of southwestern Virginia, The following section exposed along the railroad, at Ben Hur and vicinity, is typical for the region.
Geologic section, vicinity of Ben Hur, Virginia. Rockwood. Feet
17. Dark red shales with thin sandstone beds toward the top 100
16. Red sandstones and shales with beds of fossil if erous iron ore 90
15. Red and greenish shales and sandstones 100
14. Thin bedded sandstone with some red shale. 50
Clinch ( ?).
13. Heavy bedded quartzite 10
Lorraine (Bays).
12. Green and red shales with occasional thin beds of sandstone 17
11. Dark blue nodular shales crowded with Hehertella sinuate^ Other
fossils are Pterinea deniissa and other pelecypods 30
lOi Red to yellow and dark blue arenaceous limestone and shale with Modiolopsis modiolaria, Bellerophon oapax, Platystrophia Ijfnx, and
Orihorhyncula linneyi 200+
Eden (Sevier in part).
9. Dark blue to yellow shales passing upward into impure arenaceous
limestone; holds numerous bryozoa and Zygospira modesta 300
Utica (Sevier in part).
8. Olive to yellow shales partly covered 300-h
Trenton (Chickamauga in part — Cathey of Tennessee).
7. Thin bedded yellowish and blue argillaceous limestone and yellow shales with numerous fossils, Rafinesquina altemata and ConsteU
laria teres being particularly abundant 50
Trenton (Chickamauga in part — Bigby of Tennessee).
6. Thin bedded dark blue to black crystalline and argillaceous limestone with numerous bryozoa large crinoid columns, Plectamhonites seri-
c€U8 and other fossils 300
Trenton (Hermitage shales of Tennessee).
5. Shales mainly covered 300
Black River, Tyrone of Kentucky and Stones River (Chickamauga in part). 4. Heavy bedded limestone below, passing upward into light blue and
dove limestone with yellow shales. Numerous bryozoa in upper part 230
3.' Hard calcareous shales and dove or argillaceous limestones 130
2. Thin bedded dove limestones and yellow shales. Surface of limestone
bands often crowded with small ramose and bifoliate bryozoa 35
1. Heavy bedded dove to light blue limestone weathering into beds two
to four inches thick and tilled with a species of Oamarocladia 50+
Lack of space prevents a consideration of the various limestones and shales of this area at the present time. Lithologically and paleontologically the Ordovician portion of the section with the exception of the Clindi sandstone is so similar to that of central Kentucky and central Tennessee
CEMENT AND CEMENT MATERIALS.
151
that little doubt is entertained in regard to the correctness of correlation in the foregoing section. Samples of some of the limestones were analyzed with the following results :
Analyses of Ordovician limestones, Ben Hur, Virginia.
(J. H. Qibboney, Analyst)
loBoluble
Iron oxide (Fe,0„ ),alamina ( A1,0,)
lime (CaO)
Calcium carbonate (CaCO|)
Magnepia (MgO)
Magnesium carbonate (Mg(X>s)
Total
|
I |
a |
111 |
IV |
|
Percent |
Per cent |
Per cent |
Per cent |
|
8.56 |
14.00 |
7.22 |
17.80 |
|
1.68 |
2.36 |
2.68 |
1.16 |
|
50.28 |
36 40 |
49.26 |
43.66 |
|
89.48 |
82.86 |
87.96 |
77.57 |
|
0.08 |
0.06 |
0.68 |
1.11 |
|
0.17 |
0.11 |
1.43 |
2.33 |
|
99.89 |
99.33 |
99.29 |
98.86 |
V Per cent
3.34 1.12 53.08 95.50 0.33 0.69
100.65
I. Black crystalline limestone. Bed 6 (Trenton).
II. Blue argillaceous limestone, Bed 7 (Trenton).
III. Pove limestone, Bed 1 (Stones River).
IV. Dove limestone, Bed 2 (Stones River).
V. Heavy bedded limestone. Bed 4 (Tyrone formation).
Fost-Ordovician Cement Materials.
In consideration of the Portland cement materials of western Vir- ginia, the Ordovician limestones and shales are of prime importance on ac- count of their abundance and, usually, more favorable location and com- position. Two other limestone formations suitable chemically for cement manufacture obtain in this part of the State, namely, the Lewistown lime- stone of Helderbergian age, and the Greenbrier limestone of the Missis- sippian series. However, their areas of outcrop are comparatively few, of little extent, and are generally situated so far from transportation facili- ties that, with the exception of a few localities, the rock at present has little economic value.
Lewistown Limestone.
Immediately overlying the Silurian sandstones and shales, and pre- ceding the Devonian shales in this part of the Appalachian district, ma^ sometimes be found limestones varying in thickness up to 1,000 feet. These limestones are of Helderbergian age but have been mapped under several names. In northwestern and central western Virginia, these strata have been designated fiie Lewistown limestone, while limestones occupying the same position in the southwestern part of the State have been called
152 MINERAL RESOURCES OF VIRGINIA.
tlie Hancock limestone. In Giles and neighboring counties of southwestern Virginia, these limestones form a part of the Giles formation. The Lewis- town limestone is well known as a source of cement material, and therefore all of these Helderbergian limestones are here considered under that name.
The litliology and thickness of the Lewistown formation varies con- siderably even in small areas, in general, these limestones are thin bedded below, massive in the middle portion, and cherty above; consequently the lower and middle portions are of most importance as a cement rock. The cherty upper beds are massive and give rise to ridges, but the lower mem- bers are sometimes more favorably located, although much of the Lewistown area lies u])on steep mountain slopes. This occurrence is illustrated in the accompanying photograph, plate XIX. The middle beds are made up of light-colored, coarsely crystalline, fossiliferous strata and a few shaly limestones, while the lower beds contain, for the most part, flaggy lime- stone, the individual layers of which readily separate with smooth surfaces. The formation as a whole, therefore, is seen to be composed of argillaceous and calcareous strata, of which nearly all might be employed in the manufacture of cement. The basal flaggy limestone is usually of greater thickness than the other members combined, and this fact, together with its favorable composition, causes it to be of most importance as a cement rock.
General distribution, — The more extensive areas of Lewistown lime* stone are located in the western part of central western Virginia.. A por- tion of this area is mapped in detail in the Monterey, Staxuiton, and Frank- lin folios (numbers 61, 14, and 32, respectively) of the XJ. S. Geological
Survey.
In northwestern \'irginia, two occurrences of these strata may be noted. The easternmost is a narrow strip brought up by the Massanutten Mountain syncline. This has been mapped in detail by A. C. Spencer, The western area occupies portions of Shenandoah and Frederick counties in flie vicinity of North and Little North mountains.
Narrow strips of the Giles and Hancock formations are found west of the Appalachian Vallev in southwestern Virginia. These outcrops gener- ally follow the mountains or are brought up along the great faults. In either case the outcrops, almost without exception, are so far from trans- portation facilities, or the rock is of such poor quality, that the Helder- bergian limestone in southwestern Virginia cannot be regarded as a very promising future source of cement rock. The Giles and Hancock forma-
154
MINERAL RESOURCES OF VIRGINIA.
the usual lithology of the Lewistown limestone in this part of the State- The lower sandy strata of this section, however, belong to the Salina for- mation, which, at the time of publication of the folio, was not differen- tiated in Virginia.
Section on road from Warm Springs to Mountain Orove, Virginia, west
of Jackson River.
Feet
At top, alternations of impure and shaly limestone, fossiliferous 460
Wavy-bedded, massive limestone with coralline bed at base ?
Slabby limestone 400
Calcareous shale 25
Massive fine-grained sandstone, weathering light buff; probably cement rock.. 15
Sandstone 4
8haly material tO
Sandstone and sandy beds 20
At bottom, buff shales and thin, dark, semi-crystalline limestone layers 100
Reference to the two folios mentioned will show the distribution of these limestones so that detailed descriptions of these areas need not be given. Samples from the upper beds of this formation were collected for analysis.
Analyses of Lewistown limestone, Wami Springs, Mountain Orove section,
(J. H. Gibboney, Analyst)
Per cent.
U Per cent
Insoluble
Iron oxide (Fe^Og) aud alumina (Al^Os).
Lime(CaO)
Calcium carbonate (CaCO,)
Magnesia (MgO)
Magnesium carbonate (MgCOj)
14.68
1.26
43.96
78.50
2.09
4.40
Total.
98.84
19.12
2.70
42.12
75.21
1.09
2.30
99.33
I. Impure fossiliferous limestone. II. Shaly limestone.
Details of Localities.
Craigsville. — Commencing at Pond Gap and continuing for some miles southwest, the Lewistown limestone outcrops either very close to the Chesa- peake and Ohio Railroad or is crossed by it. This region therefore is of particular importance, and the favorable location of good cement rock and railroad facilities have been taken advantage of in the establishment of a Portland cement factory at Craigsville. This plant, the property of the Virginia Portland Cement Company, is of note in that it is the only well established Portland cement manufactory in the State. The following
CEMENT AND CEMENT MATERIALS.
165
1. 2, 3. 4. 5. 6.
section and analysis of the limestone and shale at this place have been published by Catlett in bulletin No. 226, of the IT. S. Geological Survey, pages 460, 461.
Section near Craigsville.
Feet
Layer hea\'y fossiliferous limestone passing into sandstone —
Very dark slaty siliceous limestone 10
Gray fossiliferous limestone 10
Daxlc, irregular siliceous magnesian limestone 2 to 20
Gray, soft, highly fossiliferous limestone 30 to 50
Dark, close-grained limestone of varying thickness and carrying vary- ing quantities of flint —
The most important beds of this series and the ones which would be used in the manufacture of Portland cement are (3) and (5). The princi- pal facts to be determined are the extent and composition of the super- imposed layers, and therefore the ease and cheapness with which (3) and (5) can be secured. The black slates of the Devonian everywhere fill the valleys in this section and afford very excellent material to combine with the limestone. The following analyses are of the limestones and shales taken from the property adjoining that of the Virginia Portland Cement Company :
Analyses of limestone and shale from near CraigsvUle,
(Charles Catlett, Analyst)
Limestone Per cent.
Shale Per cent.
Silica
Alumina
Iron oxide
Lime
Magnesia .... Volatile matter
68.07 19.08 6.16 none .64 11.17
Other analyses of the limestones and shales at Craigsville, quoted from the Cement Industry, are as follows:
Analyses of cement materials used at Craigsville, Virginia.
Limestone Per cent.
Silica (SiQ.)
Iron oxide (Fe,0,) )
Alumina (A1,0,) J
Lime (CaO)
Masnesia (MgO)
CartKm dioxide (CO,) 7
Water f
Shale Per cent.
o3.63
24 47
5.94 1.79
10.03
15(J HINEBAL HESOCRCES OF VIRGINIA.
Covington. — The more sandy portions, particularly of the Lewistown limestone, are exposed at a number of places along the Chesapeake and Ohio Railroad and vicinity between Covington and Clifton Forge. Some of these strata show a fair composition according to the first analyde quoted below, but others again contain too much areDaceoos material to be of use. The rock in this vicinity would therefore require carefol adec- tion. Shales for mixing are abundant throughout the area.
Analgm-s
of Lewistown Hnieslone, Covingtot (J. H. Oibboney, AnalfBt)
Virginia.
|
Percent. |
U PercenL. |
||||
|
Ifl 32 1.00 44. -W 79.4fi Oft-i 0 12 |
48.20 3.80 18.00 32.14 6.89 14.46 |
||||
|
Iron oxide (Fe,0,) and alumina |
(A1.0.) |
||||
|
Mafineaium carbonate (MgCO,) . |
|||||
|
9fi.89 |
98.60 |
||||
HiMiiHippi&n Limeitonea.
The particular portions of Virginia occupied by MlealBaippian (Sub- carboniferous) limestones are small when compared with the outcrops of the strata previously discussed. They consist of rather narrow strips oc- CQiTing mainly in the southwestern part of the State. The longest and also widest of these strips lies just southeast of Clinch Moontain and ex- tends from the State line on the south, northeastward to the vicinity of Bland court-house. Throughout the greater part of its length this strip is either closely paralleled or traversed by the North Fork of the Holston river. The second important area is somewhat less than the preceding in length and follows the western slope of St(nte Mountain from the southern boundary of the State northward to Little Stone Oap, where it bends and circles a portion of Powell Mountain. This area haa railroad facilities close at hand since Stone Mountain is paralleled by the Lonit- ville and Nashville llailroad, while llio Virginia and Southwestern Rail- road closely approachea, and at one point crosses the Powell Mountain line of outcrop. The other occurrences in southwestern Virginia are emaM and otherwise unimportant. The Estillvilie, Pocahontas, Tazewell.
OEMENT AND CEMENT MATERIALS.
157
and Bristol folios of the U. S. Geological Survey (Nos. 12, 26, 44, and 59, respectively), contain maps showing the larger portion of these areas in detaiL On account of the unequal development of Subcarboniferous for- mations in the northwestern and southwestern halves of this general re- gion, the limestones of this age in the former portion have been mapped as the Greenbrier, and in the latter as the Newman limestone.
Oreenbrier limestone, — This well known limestone formation is best developed in Greenbrier county. West Virginia. In general, the Greenbrier consists of massive dark blue limestone, often cherty in the lower part, purer in the middle, and becoming shaly toward the top. The shales of the upper portion are quite calcareous and pass without any noticeable break into the less calcareous shales of the succeeding formation.
Probably the best and most detailed section of the Greenbrier lime- stone in Virginia may be seen along the Norfolk and Western Railroad near Lunch, in Giles county. Here, all of the beds are fairly well expo^d and the section may be considered as typical for the region. For this reason all of the variations in the strata at this point were noted and samples taken for analysis. The section observed here is, in ascending order, as follows :
Geologic section, Oreenbrier limestone, vicinity of Lurich, Virginia.
1. Dark blue to black heavily bedded liinestx)ne with many small chert
nodules. ProductuSt ZaphrentiSf and Fenestella observed 176
2. Drab and yellow calcareous shales with occasional bands of compact blue
limestone 180
3. Massive blue and argillaceous limestone with a few shaly beds in the upper
part 00
4. Dnib and blue shales SO
5. Compact blue-black, fine-grained limestone alternating with coarsely cryn-
tafline fossiliferous strata, with blue limestone and yellow shales in upper part 160
6. Compact blue to black argillaceous limestone in thin flaggy layers, much
fractured 1 79
7. Thin bedded blue limestone with beds of blue and yellow shale 400
Analyses of Oreenbrier limestones and shades, Lurich, Virginia, section.
(J. H. Oibboney, Analynt)
I 11 1 Pr. ct Pr. ct
III Pr. ct
Inaolable. , 8.38 31.82: 48.80
lion oxide (Fe.O,) and alum-, , I
ina(Al,0,) ' 1.20 1.80! 4.52
LUne (OrO)..... i 49.24
Calcium carbonate (CaCO,) j 87.93
34.W)! 23.80
62.32. 42.86 29.53
(MgO) 0.80 1.43; l.lOl O.aS
3.80 8.24
0.681 1.04 52.74 48.52 94.18, 86.64
0.401 1.87
VIII IX
Pr. ct
41.38! 8.42
Magnesium carbonate (BlgCO,) I 1.67' 2.99 2.31 1.75 0.84' 3.^)2
4.26
28.80
51.43
1.04
2.19
XI
Pr. ct Pr. ct Pr. ct
4.46
1.00 1.66
48.66 61.22
86.71 91.46
1.82 0.51
2.77 1.08
16.10! 23.06 1.461 2.74
43.84
78.28
2.07
4.34
39.62
70.76
0.78
1.64
Total I 99.18' 98.931 98.49 99.20| 99.60 99.84' 99.24 08.90 98.56 99.18J 98.19
158
MINERAL RESOURCES OF VIROINIA.
I. Dark blue limestone from strata free from chert nodules. Bed 1.
II. Dark limestone from usual cherty layers. Bed 1.
III. Drab calcareous shales. Bed 2.
IV. Yellow shales. Bed 2.
V. Blue fossiliferous limestone. Bed 2.
VI. Bluish-black compact limestone. Bed 3.
VII. Drab shale. Bed 4.
VIII. Compact, bluish-black limestone. Bed 5.
IX. Coarsely crystalline crinoidal limestone. Bed 6.
X. Flaggy black limestone. Bed 6.
XI. Thin bedded blue limestone. Bed 7.
Newman limestone. — Following the sandy Devonian and MiBsissippian shales in southwest Virginia, is a limestone formation varying from 1.000 to 2,600 feet, to which the name Newman limestone has been applied from its outcrop on Newman Ridge in Tennessee. The principal areas of out- crop in Virginia have been indicated under the discussion of the Missis- sippian limestones of the southwestern part of Virginia, The more mas- sive strata of the Newman limestone are characteristic of its lower part, while higher in the formation considerable calcareous shale deposits are found. Chert, likewise, is most abundant in the lower strata, although a considerable portion of the limestone layers are free from it. Several miles southeast of Mendota, Virginia, the area of outcrop south of Clinch Mountain is traversed by the Virginia and Southwestern Bailroad, and here for a distance of 3 or 4 miles, exposures of this limestone may be seen.
Analyses of Newman limestone.
(J. H. Gibboney, Analyst)
Insoluble
Iron oxide (FejOj) alumina ( AljOg)
Lime(CaO)
Calcium carbonate (CaCO,)
Magrnesia ( MgO)
Magnesium carbonate (MgCO,). . . .
|
I |
II |
lU |
IV |
V |
|
Per cent. |
Per cent. |
Per cent. |
Per cent. |
Per cent. |
|
7.72 |
10.40 |
8.56 |
7.22 |
15.82 |
|
0.68 |
0.72 |
1.00 |
0.41 |
3.40 |
|
60.20 |
48.64 |
49.24 |
60.96 |
43.98 |
|
89.64 |
86.85 |
87.92 |
91.00 |
78.54 |
|
0.89 |
0.86 |
0.88 |
0.65 |
0.47 |
|
1.87 |
1.71 |
1.86 |
1.37 |
0.99 |
|
99.91 |
99.68 |
99.33 |
100.00 |
98.75 |
T. Massive blue limestone, 2 miles southeast of Mendota, Virginifk.
II. Dove-colored limestone, 2 miles southeast of Mendota, Virginifk.
III. Dark blue limestone, vicinity of Horton Summit, Scott county, Virginia,
IV. Dark blue limestone, 1 mile north of Big Stone Gap, Lee county, Virginia, V. Massive blue limestone, Ollinger Gap, Lee county, Virginia.
Pennington shale, — Succeeding the Mississippian limestones of south- western Virginia is a shale formation which, in the event of the use of the
OBMENT AND GEMBNT MATERIALS. 159
limestone as a cement material, would be found of importance for mixture. This shale, which in one part of this region has been mapped as the Pen- nington shale, and in another as the Bluefield shale^ is, in general, cal- careous at the bottom and sandy in its upper part. The lower portions only, therefore, are of importance in the present connection.
The Pennington shale, named from Pennington Gap in Lee county, is about 1,000 feet thick in its typical area of outcrop. It is made up of calcareous and argillaceous shales with beds of heavy sandstone. The cal- careous portions are limited mainly to the base, while the top of the forma- tion is composed of red and purple shales. The formation is well exposed at Big Stone Gap as well as at Pennington Gap.
In the typical areas of Greenbrier limestone, the upper or shaly member of this formation passes gradually into a shale formation named from Bluefield, Mercer county, West Virginia. like the Pennington, the Blue- field shale is composed of calcareous and argillaceous shales with sandstone beds; similarly, the more calcareous beds are at the base and the sandy layers are most abundant at the top. Between these extremes is found every variation in composition. The thickness of the Bluefield shale is usually about 1,300 feet.
Travertine Deposits.
Many of the numerous springs of western Virginia contain carbonate of lime in solution. These have been and are still depositing considerable quantities of calcareous tufa or travertine. Small deposits of such ma- terial have been noticed in various parts of this region, and these, if favorably located and in suflBcient quantity, would undoubtedly be of value in cement manufacture. Such materials have been used in the making of Portland cement, although with the abundant limestone of western Vir- ginia, their use is less likely. A noteworthy example of the use of such material in cement manufacture is at the plant of the Pacific Portland Cement Company in Selano county, California, where travertine and clay are the ingredients mixed. In certain portions of Staunton. Virginia, as noted by Mr. Catlett, the foundations of the houses have been cut in a calcareous marl or travertine 10 or 12 feet deep. An analysis of this deposit is presented below. The surface indications of these travertine deposils are usually not sufficient to estimate the quantity or extent of iiie lock, and drilling would be necessary to determine these points.
160 MINERAL llESOURCES OF VIRGINIA.
Analysvi of travertine deposit, Stminton, VirginuL
(Charles Catlett, Analyst)
Per cent.
Insoluble 5.92
Iron oxide (FCjO,) and alumina (AI2O3) 62
Lime (CaO) 50.62
Calcium carbonate (CaCO,) 90,40
Magnesia (MgO) 30
Magnesium carbonate (MgCOj) .63
Total 97.57
NATURAL CEMENT.
The relation of natural cements to other cements has been briefly noted on a previous page. An extended and valuable treatise on this subject is presented by Mr. Eckel in his ^'Cements, Limes and Plasters." In the present article, the writer wishes to point out briefly the distribution of ihc limestones suitable for this kind of cement, to give analyses, and to indi- cate the present status of the natural cement industry in Virginia.
Under ordinary circumstances the value of natural cement is too small to allow it to be shipped any distance with profit. Therefore, the manufacturer must have a home market and little competition. The raw material is an argillaceous limestone carrying from 13 to 35 per cent, of clayey material, of which about 10 to 22 per cent, is silica, while alumina and iron oxide together may vary from 4 to 16 per cent. Unlike Portland cement rock, the percentage of magnesium carbonate may run high, the reason for this being, that in natural cements the magnesium and lime are regarded as interchangeable. The hydraulic properties do not depend upon the percentage of lime but upon the clayey materials, which therefore are the important factors to consider in the rock analysis. Limestones having a composition within the limits just indicated are more or less abundant at several horizons in western Virginia, but probably the only one which will meet all the requirements and prove of economic importance is the argillaceous magnesian limestone of the lower part of the Shenan- doah group. This rock, although often very similar in lithologic characters to the dolomitic limestone found higher in the Shenandoah, can be recog- nized as containing argillaceous matter by the clayey odor given forth when breathed upon.
These limestones (Sherwood) and shales (Buena Vista) have been de- scribed on page 94, where their use in the making of natural cement was noted. These strata may be found at various points along the eastern side
OEMENT AND OEICSNT MATERIALS.
161
of the Appalachian Valley so that a considerable supply of the necessary materials should be available.
The clayey magnesian Cambrian limestone used by the James Biver Cement Company at Balcony Falls, Bockbridge county, Virginia, in mak- ing natural cement, gave the following results upon analyses :
Analyses of natural cement rock, Balcony Falls, Virginia.
Silica (8iO,)
Alumina (AU),) "i
Iran oxide (Fe,0,). /
Lime (CaO)
MagDeeia (MgO)
Carbon dioxide (CO,)..
Per cent
J7.38
7.80
34.23
9.51
30.40
{
II Per cent.
17.21
tr.
1.62 24.85 16.58 37.95
III Per cent.
17.30 6.18 1.62 29.54 13.05 34.17
I. E. C. Boynton, analyst. Gillmore, "Limes, Cements, and Mortars/' p. 125. XL C. L. Allen, analyst. "The Virginias," vol. 3, p. 88. III. Average of preceding two analyses.
This same belt of magnesian limestones and shales of Cambrian age crosses Virginia into West Virginia and Maryland. Several small natural cement plants have been established in this district at various times, par- ticularly near Antietam, Maryland, and Shepherdstown, West Virginia.
Analyses of natural cements, Shepherdstovm^Antietam District, West
Virginia^Maryland,
Silica (SiO,)
AlomiDa(Al,0,)... Iron oxide (Ke,0|) Ume (CaO)
Per cent.
II Per cent.
Magnesia (MgO)
Alkalies {Kfi, Na,0). Salphar trioxide (SO,)
Garbon dioxide
Water.
}
33.42 10.04 \
6.00/ 32.79
9.59
0.60
n. d.
7.66
36.51
9.36
34.83
11.33
1.25
1.49
5.13
III Per cent.
33.50
/ 10.44 \
I 3.25/
29.38
13.37
n. d.
1.15
7.15
IV Per cent.
15.97
7.69
23.72 16.60
n. d.
0.71
34.82
I. Shepherdstown, W. Va. Quoted by Cummings. "American Cements," p 36.
II. Shepherdstown, W. Va. C. Richardson, analyst. Brickbuilder, vol. 6, p. 229.
III. Antietam, Md. C. Richardson, analyst. Brickbuilder, vol. 6, p. 229.
IV. Antietam, Md. C. Richardson, analyst. Brickbuilder, vol. 6, p. 151.
Limestones suitable for the manufacture of natural cement occur in «)uthwe8tem Virginia, particularly along the eastern half of the Appa-
162
MINERAL RESOURCES OF VIRGINIA.
lachian Valley. Greologically, these succeed the siliceous deposits of Lower Cambrian age and form the base of the great Shenandoah limestone group. Geographically, however, these particular areas cannot be indicated with- out detailed mapping, requiring long field work. During the progress of his work on the lead and zinc deposits of Virginia, Dr. T. L. Watson col- lected samples of these limestones for analysis. The results were published in Bulletin No. 1 of the Virginia Geological Survey, and analyses selected from this publication are quoted below.
Analyses of Shenandoah limestone.
Insoluble residue..
8iO,
no,
A1,0,
Fe,0,..
MnO
CaO
MgO
BaO
K,0
Na.0..
H,6 J00°C- \ H,0 100«>Ct /- C50.
Total.
|
I |
II |
III |
IV |
|
Per cent. |
Per cent. 0.694 |
Per cent 0.46 |
Percent |
|
2.90 |
0.20 |
||
|
trace |
.078 |
trace |
trace |
|
none |
none |
none |
none |
|
0.43 |
0.344 |
0.24 |
0.87 |
|
0.94 |
0.19 |
0.17 |
0.22 |
|
none |
0.193 |
0.37 |
trace |
|
30.06 |
29.085 |
29.50 |
30.71 |
|
18.41 |
20.54 |
19.93 |
21.66 |
|
none |
none |
trace |
none |
|
0.24 |
0.22 |
0.66 |
0.12 |
|
0.21 |
0.38 |
1.03 |
0.10 |
|
8.30 |
2.58 |
8,78 |
3.92 |
|
48.98 |
46.40 |
44.01 |
48.88 |
|
none |
none |
none |
none |
|
none |
none |
none |
none |
|
100.47 |
99.599 |
99.99 |
101.08 |
I. Limestone. Massive ^ayish black fine granular, crushed and recemented with stringers of pure white calcite. Martin property, two and three- quarter miles southwest of Roanoke City, Roanoke county, Virginia. Dr. W. E. Barlow, analyst. *
II. Limestone. Grayish white and moderately coarse crystalline. Specimens taken from the 100-foot level in the Austinville zinc and lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst.
III. Limestone. White, coarsely crystalline, and crushed. Specimens taken from
the 80-foot level at bottom of open cut, in the Austinville zinc and lead iiiine.s, Wythe county, Virginia. Dr. W. E. Barlow, analyst.
IV. Lime'vtonc. White and medium crystalline. Specimens taken from the 80-
foot level at bottom of open cut, in the Austinville zinc and lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst.
GEXEHT INDUSTRY IK YIROIHIA.
Although the cement industry may be said to be in its infancy in western Virginia, yet the manufacture of this important economic pro-
CEMENT AND CBHEHT UATERULB. 163
duet bu been carried on for many yeare at one locality, and for a less time •t UkOtlMr. Natural cement has been burned near Balcony Falls, Bock- bridge connty, for over half a century. The demand for a cheap and trust- worthy cement for uee in the conatmctiou of masonry, locks, and vails on tKe Jamea BItct Canal, led to the discovery of the hydraulic properties of tite rode osed at this plant. Since that time a natural cement has been manafictiired at this locality almost continuously, the James River Cement ConqMny operating the plant at the present time. The rock used ia a steel Uoe, ugillaceouB limestone of Jjower Cambrian age, with an average thick- sen of twelve feet. For a description and history of this cement plant, the Mtder ia referred to an anonymous article published in the Engineer, September 29, 1899.
Bot a single plant for the manufacture of Portland cement is in opera- tioB in Virginia, namely, that of the Virginia Portland Cement Company at Cniffinlle, Augusta county. The geologic section at Craigsville and ^aal^pBB of the rock employed have been given on a previous page. As Ihc jaBfl>odi employed by the Virginia Portland Cement Company are those ol a ^MTgBf modem plant, a description of the process of manufacture is baw introduced.
"Big materials used in the manufacture of the Old Dominion cement lit Lawirtows limeetone and shale. The principal limestone quarry is lo- ttttAtUBjUe and one-eighth from the plant, and the shale quarry three- qaartnw of a mile.
- Ibe diale is crushed at the quarry and brought dovn on a standard pap track to the scale house, where it is elevated into bins over the wtOm.
The limestone is brought to the scale house on a narrow gauge track in care containing about 3,000 pounds of limestone. The limestone cars are weighed and the proper percentage of s^halc is dropped from the bins onto the limeatone, and the narrow gauge car is then picked up by a cable and carried to i 7-^ Gates crusher, through which the limestone and shale paes together.
The output of the crusher goes throu^ a revolving screen and the ' TejectiouH from the screen are passed through a No. 3 crusher. From the cruahers, the rair material is elevated on a belt conveyer to 12 tanks con- taining about 70 tons each. The material is drawn from the bottom of ' I thwe tanks into a belt conveyer, which carries it to the rotary dryers, i in nnmber. From the dryers, the material is carried on a belt conveyer to " " atatiil mill, where it receives ita preliminary grinding in ball
164 MINERAL RESOURCES OF VIRGINIA.
mills^ and its fine grinding in pebble mills. The outfit of this raw material mill consists of 3 Erupp ball mills^ 2 Smidth kominnters^ 3 Kmpp pebble mills and 3 Smidth pebble mills.
The ground material is conveyed by means of belt conveyers, elevators and screw conveyers to tanks over the kilns, and is fed into the kilns by conveyers in the bottom of tanks. The rotary kilns are 10 in number, 60 feet long, 6 feet in diameter, slightly inclined from the feed end to the discharge end. Powdered coal is used as fuel for burning the raw ma- terial. It is blown in by a low pressure blast of air and ignites instantly. The heat generated is about 2,600°. The coal is first dried in rotary dryers and passed through pebble mills similar to those used for grinding the raw material.
The material passes from the kilns in the form of clinker and is ele- vated into coolers through which a blast of air is forced. Prom the bottom of the coolers, it is drawn by means of a belt conveyer to the clinker storage, where it is allowed to age for about three weeks. Underneath the floor of the clinker storage are belt conveyers, which convey the clinker to the cement mill.
The process in the cement mill is a repetition of that in the raw mate- rial mill. The cement grinding machinery consists of 2 Krupp ball mills, 3 Smidth kominuters, 2 Krupp pebble mills, and 4 Smidth pebble mills. From the cement mill, the finished cement is conveyed by belt conveyers to the 2 stockhouses, where it is stored in bins until such time as it is shipped out. The cement is drawn from the bins into screw conveyers, elevated into bins over the bag packers and barrel packers. The bag packers are operated by hand and the barrels are packed by power.
The storage capacity is 100,000 barrels. The present output of the plant is between 1,800 and 1,900 barrels per day. Construction work is at present under way to increase the capacity of the plant to 3,000 barrels per day.
The power equipment of the plant includes 8 Sterling water tube boil- ers, 1 Hamilton Corlis engine of 750 H. P., 1 Cooper Corlis engine of 1,100 H. P., and 1 Westinghouse engine of 250 H. P. Electric generators located in the power house furnish current to motors which operate the kilns and a large part of the conveying machinery. The grinding ma- chinery is belted to shafting.
As the mill is located so far away from any city, it was necessary for the company to provide homes for its employees. The company has ac- eoiii2nodati0nB for some 200 families, runs a commissary store, village
OEMENT AND CEMENT MATERIALS.
165
water works, etc. The company employs a physician, maintains a hos- pital, and close attention is paid to sanitary inspection. The number of employees is about 425.
Beferences.
Beports treating of the limestones and shales of Virginia with refer- ence to their use as cement materials have been few. Numerous papers treating of the geology of Appalachian Virginia, particularly of the south- western part, have been published, but few of these have direct bearing on, or are of use in, the location of cement rock. Those which may be found of value in this respect are noted in the following bibliographic list.
The U. S. G^logical Survey has mapped all of western Virginia geo- graphically, this area being included in 27 quadrangles. However, only 8 folios of the Geologic Atlas of the United States touching this region have been published. These are the Harper's Ferry folio for northwestern Virginia; the Staunton, Franklin, and Monterey folios for central western Virginia; and the Pocahontas, Tazewell, Bristol, and Estillville folios for southwestern Virginia. These folios contain topographic sheets, areal and economic geologic sheete, and structure sections of the areas studied, with text descriptions of the geology and mineral resources. However, only the 4 last mentioned give maps in which the argillaceous and pure limestones of Ordovician age are separated from the impure Cambro-Ordovician series.
Anonymous.
Eckel. E. C.
Bassler, B. S.
Catlett, C. Vredenburg, W
Natural Cement.
James River, Virginia, Cement Co. Engineer (Lon- don), September 29, 1899.
Natural cement resources of Virginia. IT. S. (Jeologi- cal Survey, Bulletin No. 225, 1904, 457-461.
Portland Cement.
Cement materials of the Valley of Virginia. U. S. Geological Survey, Bulletin No. 260, 1905, 531-534.
Portland cement resource of Virginia. U. S. Geolog- ical Survey, Bulletin No. 243, 1905, 212-323.
Cement resources of the Valley of Virginia. U. S. Geological Survey, Bulletin No. 225, 1904, 457-461.
The Virginia Portland Cement Company's Works, Craigsville, Va. Engineering Record, July 28, 1900. Cement Industry, 1900, 132-141.
]66 MINERAL RESOUBCES OF YIROINIA.
Miscellaneoiis.
Analyses of the rocks, references, maps, or descriptions of the limestones and shales of western Virginia are given in the following works:
Boyd, Charles R. The Mineral Resources of Southwestern Virginia.
Wiley and Sons, New York, 1881, 381 pages.
Campbell, H. D. The Cambro-Ordovician Limestones of the Middle
Portion of the Valley of Virginia, American Journal Science (4), 1905, XX, 446-447.
Campbell, M. R. Paleozoic Overlaps in Montgomery and Pulaski
Counties, Virginia. Bulletin Geological Society America, 1894, V, 171-190.
Campbell, J. L. Silurian Formations in Virginia. American Journal
Science, (3), 1879, XVIII, 16-29, 119-128.
Campbell, J. L. and H. D. William B. Rogers' (Jeology of the Virginias. A
Review. American Journal of Science (3), 1886, XXX, 367-374; 1886, XXXI, 193-202.
Darton, N. H. Notes on the Stratigraphy of a portion of Central
Appalachian Virginia. American (Jeologist, 1892. X, 10-18.
Eckel, E. C. Cement Materials and Industry of the United States.
U. S. Geological Survey, Bulletin No. 243, 1906.
Cements, Limes and Plasters. Wiley and Sons, New York, 1906, 712 pages.
McCreath, A. S., and d'lnvilliers, E. V. The New River-Cripple Creek
Mineral Region of Virginia. Harrisburg, Pa., 1887. 18, 24, 40, 51, 54-68, 70-76, 82, 89.
Rogers, W. B. Reports of the Progress of the Geological Survey of
the State of Virginia (1836-1841).
A Reprint of the Geology of the Virginias. New York, 1884.
Spencer, Arthur Coe. The Geology of Massanutten Mountain in Virginia.
Washington, D. C, 1897.
Stevenson, John J. Notes on the Geology of Wise, Lee and Scott Counties,
Virginia. Proceedings American Philosophical Society, 1880, XIX, 88-107.
A Geological Reconnaissance of Parts of Lee, Wise^ Scott and Washington Counties, Virginia. Pro- ceeding American Philosophical Society, 1881, XIX, 219-262.
CLAYS. 167
Notes on the Geological Structure of Tazewell. Bussell, Wise, Smyth and Washington Counties of Virginia. Proceedings American Philosophical Society, 1885, XXII, 114-116.
A Geological Reconnaissance of Bland, Giles, Wythe and portions of Pulaski and Montgomery Counties, Virginia. Proceedings American Philosophical Society, 1887, XXIV, 61-108.
Stose, G. W. The Sedimentary Rocks of South Mountain, Pennsyl-
vania. Journal of Geology, 1906, XIV, 211.
Watson, Thomas L. Lead and Zinc Deposits of Virginia. Virginia
Geological Survey, Bulletin No. 1, 1905, 166 pages.
III. CLAYS.
■ BY HEINRICH RIE8. DEFnriTION AND PROPERTIES OP CLAY.
Clay is one of the most curious and least understood of our common mineral products^ and various investigators have spent much time in attempts to discover the causes of its peculiar properties. In some cases they have partially succeeded; in others it must be admitted that while they have partly solved the problem, they are nevertheless still very far from a complete and satisfactory interpretation of the phenomena dis- cussed.
Man at a very early period in the earth's history discovered the peculiar qualities of the common substance known as clay. That its use- fulness has steadily increased is evidenced by the fact that in 1904, the value of clay products made in the United States alone exceeded $130,- 000,000, which was greater than the value of other important products such as gold, silver, copper, and petroleum, and was only outranked by iron and coal. This being the case, we can justly regard clay as one of our most important mineral resources, although up to a few years ago it was quite neglected by both government and state surveys.
To the unaided eye, clay usually appears so fine-grained that most of its component grains cannot be identified, although some particles of quartz, or small scales of mica are not infrequently recognizable. Micro- scopic examination, however, reveals the presence of a number of small mineral grains, many of which are under one one-thousandth of an inch in diameter. In addition to these there are particles of organic matter as
1^8 MINERAL RESOURCES OF VIRGINIA.
well as other small bodies of non-crystalline character, which are classed as colloids, and may be of either organic or inorganic origin. The mineral fragments making up the bulk of the clay represent a variety of com- pounds in all stages of decomposition, but their properi;ie8 and eflPect on the clay will be left until a later page.
OKIOnr OP CLAY.
So far as we know clay results primarily from the decomposition of other rocks, and very oft«n .fTom.rojpks containing an appreciable amount of the mineral, feldspar! 'There We sopfie rocks, however, that contain practically no feldspar which, on weathering, yield a most plastic clay. In all of these clays there is found a variable amount of the mineral kaolinite, which is of secondary origin, i. e., it is derived from other minerals by decomposition. This is termed the clay base.
In order to trace the process of clay formation, let us take the case of granite, a rock which is commonly composed of three minerals, namely, quartz, feldspar, and mica. When such a mass of rock is exposed to the weather, minute cracks are formed in it, due to the rock expanding when heated by the sun and contracting when cooled at night; or there may be joint-planes formed by the contraction of the rock as it is cooled from a molten condition. Into these cracks the rain water percolates and, when it freezes in cold weather, it expands, thereby exerting a prying 2)ction, which further opens the fissures, or may even wedge oflP fragiiicnts of the stone. Plant roots force their way into these cracks and as they expand in growth, supplement the action of the frost, thus further aiding in the breaking up of the mass. This process alone, if kept up, may reduce the rock to a mass of small angular fragments.
CLASSIPICATION OP CLAYS.
The state of Virginia contains a variety of clays, which are adapted no doubt to a wide variety of uses, but many of the deposits have remained undeveloped, because little is known regarding them, the only ones which have been systematically* studied being those of the Coastal Plain or the Tidewater belt.
In discussing the clays of Virginia it might perhaps seem more prac- tical to group them according to kinds, but since one type of clay may be often used for the manufacture of several types of clay-products, such a mode of treatment does not form a satisfactory basis and therefore a grouping by formations is adopted.
MINintAl. HKSMCItiKS nr VlliiilMA
I'I,ATE XXI.
■*■'«' ^'-A--.-. ■■\W
LIMESTOXK WEATIIKRlXi;, lUiK K l'],ANT AMI CLAY PET.
CLAYS. 169
The clays of Virginia can be divided into two groups, namely, residual and sedimentary. The residual clays have been formed by the weathering of rocks, involving processes of disintegration and decomposition. As a result of this we find the residual clay overlying the parent rock from which it was derived, plate XXI, figure 1, These deposits are of variable thickness depending partly on the depth to which the rock has been changed, and partly on the amount of erosion which they have suflEered since their formation. Knowing this we should expect to find heavier deposits on a flat surface, than on a sloping one where the rain-wash is more active.
The sedimentary clays represent deposits which have been laid down under water, one layer on another, the materials composing them consisting of the products of rock decay, which have been removed by erosion from the land surface, and washed down into the lakes, or seas, where they have finally settled.
Eesidual Cla3rs.
These predominate in the belt underlain by the crystalline rocks. The crystalline rocks, consisting of granite, gneisses, and schists, with some intrusives, extend across the State from north to south in a belt of increasing width, whose western boundary follows approximately a linp running from Harper^s Ferry, southwestward. The eastern edge coincides somewhat closely with the "fall-line." Residual clays are not uncommon throughout this area, but they are usually quite ferruginous and therefore red-burning. Their main use is for the manufacture of brick and drain tile, and some of the smoother deposits have been employed for making smoking pipes.
Here and there the decomposition of pegmatite veins has yielded clays of high grade, free from iron, and sometimes suflBciently white to be used for the manufacture of white-ware products. Deposits of this type known as kaolins have been found in Henry, Nelson, Patrick, and other counties in the Piedmont region. In the former county, Henry, a kaolin deposit is being worked near Oak Level station, by John Sant and Company of East Liverpool, Ohio. (Plate XXII.) The clay occurs as a series of veins, catting across the schists of that region. It is mined by circular pits and, before shipment to market, it is put through a washing process in order to free it from grains of sand, mica, and other mineral impurities, ^hich are present in small quantities.
170 MINERAL llESOURCES OF VIRGINIA.
Tho following analyses give the composition of the crude (1) and
washed (II) kaolin from this locality:
I II
Per cent. Per cent.
Silica (SiO,) 60.82 46.70
Alumina (AlA) 24.00 39.18
Ferric oxide (FcaO,) 94 .78
Lime (CaO) 28 .44
Magnesia (MgO) 11 .06
Potash (KaO) 2.59 1.78
Soda (NaiO) 10 .20
Titanic oxide (TiO,) 12 .28
Water (H/)) 5.52« 12.09*
Total 100.64 100.50
O Includes 1.98 per cent, of moisture. (*) Includes 2.00 per cent, of moisture.
A deposit of refractory residual clay is said to occur at Bon Air, J) miles west of Eichinond, and is well exposed in the cut of the Southern Railway. The following analysis of a washed sample is given by Dr. Froehling :
Per cent.
Silica (SiO.) 40.71
Alumina (AlA) 37.02
Ferric oxide ( FeA) MO
Lime (CaO) 25
Magnesia (MgO) 14
.Alkalies (NaA K,0) trace
Loss on ignition 14.10
Total 99.02
This deposit is said to have been worked for several years.
A bed of refractory clay has also been exploited near Clayville, but tlie deposit is now exhausted.
A second deposit reported by Dr. Froehling occurs on the land of F. B. Deitrick, at Lorraine, in Henrico county. This clay is said to be quite fnM3 from grit, very plastic, and to have an air and fire shrinkage of 12 and 7 \yeT cent., respectively. It burns to a dense hard brick of bright red color at 1750^ Fahr. The same analyst gives its chemical compoa-
tion as follows:
Per cent.
Silica (SiO,) 02.80
Alumina (AlA) 21.30
Ferric oxide (Fe^O,) 4.80
Lime (CaO) 54
Magnesia ( MgO ) 57
Potash (KaO) 2.35
Soda (Na,0) 83
Loss on ignition 7.00
Total 100.19
KAOLIN PIT AND WASHING PLANT. HENRY COUNTY. VIRGINIA.
,. • --n
I "
...l-,- I
■ • I. .
»:-.i'
CLAYS, ITl
Additional localities are given by the same analyst as follows: A deposit of crude kaolin occurs on the property of the Kaolin Mining and Manufacturing Company near Abbeyville, Mecklenburg county. The deposit is said to be of considerable size, and is in 3 layers, separated by thin bands of ocher. The following analyses give the composition of the individual layers:
Ist layer 2nd layer Srd lav«r
4 feet thick. 2 feet thick. SO feet thick.
• Per cent. Per cent. Per cent.
Silica (SiO,) 69.40 69.01 60.36
Alumina ( AlA) 20.85 20.97 24.82
Ferric oxide (Fe,0,) 1.40 1.36 1.60
Lime (CaO) .14 .11 .40
Magnesia (MgO) trace trace .43
Potash (K,0) 2.03 2.01 2.60
Soda (Na/)) 7?» 1.19 4.72
Titanic oxide (TiO,) 66 .66 1.01
Loss on ignition 4.70 4.62 3.93
ToUl 99.96 99.92 99.87
The clay is stated to be of low plasticity, with 2.6 per cent, air shrink- age, and 2.5 per cent, fire shrinkage at 2250'' F. It bums to a cream color.
Another deposit of kaolin is reported on the land of Carroll Brothers, near Lynchburg, in Campbell county. The analysis given shows:
Per cent.
Silica (SiOs) 45.13
Alumina (AljO,) 37.06
Ferric oxide (FeA)* 24
Lime (CaO) 85
Magnesia (MgO) 23
Soda (Na,0) 52
Potesh (K,0) 31
Water and loss 14.60
Sulphuric oxide (SOg) 01
Phosphoric oxide (PjOg) .06
Total 00.00
At the same locality there is said to be found a yellow clay used for bright red brick and a blue clay adapted to pottery manufacture. 1'he composition of the two is given as follows:
172 MINERAL RESOURCES OF VIRGINIA.
Yellow clay. Blue clay.
Per cent. Per cent.
Silica (SiOa) 61.76 44.70
Alumina (AlA) 21.46 36.69
Ferric oxide ( Fe,Og) 6.76 3.46
Lime (CaO) 66 1.76
Magnesia (MgO) 33 .12
Soda (Na,0) 87 .16
Potash (K,0) 73 JI7
Water and loss 7.22 13.66
Sulphuric oxide (SO.) 02 .08
Phosphoric oxide (PjOb) .06
Total 99.86 99.79
About a half mile north of Roseland^ Nelson county, the Pittsburg Kaolin Company mined kaolin on a very extensive scale for many years, from altered pegmatite dikes. An extensive plant was erected at the mines at a reported cost of $50,000, for preparing the product for market It was used in paper making. The mill was elaborately equipped with machinery for crushing, screening, and drying the kaolin by steam. Mining is said to have commenced in 1890 and was suspended about 10 years ago.
A deposit of residual clay, 7 miles southwest of Sherando at
Waynesboro, was analyzed by Dr. Frochling with the following result:
Per cent.
Silica (SiO,) 47.90
Alumina (Al/),) 39.86
Ferric oxide (Fe,Og) 24
Lime (CaO) 23
Magnesia (MgO) 19
Alkalies (Na,0, K,0) 1.55
Loss on ignition 9.85
Total 99.82
The Cambro-Silurian shales and limestones yield an abundance of impure residual clay, which clay is well adapted to brick manufacture. These clays, which are likely to be used throughout the Great Valley region, are chiefly red-burning, so far as known. In addition to being adapted to brick manufacture they can also be employed for mixing with limestone to make Portland cement.
Sedimentary Clays.
These are abundant in both the Coastal Plain area, where they are usually of unconsolidated character, and west of the Blue Ridge, in which region they are mostly of a hard and shaly nature. They are widely dis- tributed geologically, and the geological distribution agrees also somewhat closely with the geographical range.
CLAYS. 173
THE COASTAL PLAUT CLAYS.
The deposits of the Coastal Plain consist of a series of unconsolidated beds of sand, gravel, clay, and marl, which may be locally indurated by the presence of a cement of iron oxide or lime carbonate. The strata have in general an easterly dip, which varies from 30 feet per mile in the lowest formations to less than 6 feet per mile in the highest ones. The effect of such a low dip is to make the beds appear almost horizontal. Qood sections, such as are usually afforded along the valleys and hill sides, are scarce, because the Coastal Plain is an area of low relief that slopes gradually from the Piedmont hill country to the ocean border. The few good sections that exist are to be found in the low bluffs bordering some of the more important rivers, such as the James.
Since the formations dip southeastward the oldest ones will outcrop at the western edge, and any bed outcropping at this point will be found at a much greater depth near the sea coast. Or again, if a formation were found at sea-level at a point midway between the coast-line and the *'fall- line " its dip would carry it higher up if it were followed inland, or lower down if followed toward the coast.
The Coastal Plain formations range in geologic age from Jurassic ( ?) to Qnartemary, but of these only the Eocene and Miocene beds of the Tertiary, and the Pleistocene of the Quaternary, have thus far proved to he of marked value to the clay-worker. The others contain scattered beds of clay, but sands are the predominating materials in most of them.
The Eocene clays are best developed in the region south of Stafford court-house, where they form rather promising outcrops, but have not yet I'^n developed.
The Miocene clays are best known south of Richmond, in the vicinity of Curie's Neck, and Bermuda Hundred. This same formation also carries extensive beds of diatomaceous earth or clay, which is well exposed at Hichmond and along the Rappahannock river.
The Pleistocene clays occur as more or less basin-shaped deposits, which are widely scattered over the surface of the Coastal Plain region, *^d rest on top of the other formations.
Economic value of the Coastal Plain clays, — Nearly all the clay de- P^^ts noted in the Coastal Plain area, whatever their geological age, are °' lenticular or lens-shaped character. The majority are red-burning, ^® only a few are buff-burning. No white-burning clays have thus ^ been found; but even though they lack in variety, so far as their
174 MINERAL RESOURCES OF VIRGINIA.
color-burning qualities are concerned, it is probable that their possible uses are more numerous than is now supposed.
The localities from which samples of the Coastal Plain days were collected by the writer and subjected to laboratory study, the results of which are given in the table opposite page 175, are shown on the accom- panying map, plate XXIII. The characters of the clays in the more im- portant areas are separately discussed below.
DESC&IPTION OF CLAY A&SAS.
The Alexandria Area and Vicinity.
This area is the most important brick-making district in the Virginia Coastal Plain region. It cannot be said that this marked local expansion of the clay-working industry is due to the more abundant occurrence of clay at this point, but rathej to the fact of its nearness to an active and important market, namely^ the city of Washington. Nearly all the brick yards of the area here described are situated so close to the city, that the product is hauled across the.riyer by teams, and the daily continuous procession of wagons loaded with brick indicates the demand for the Virginia product. ►"./" •'
The clays used in the Alexandria district are the Columbian loams, which underlie the low hills around Alexandria, Arlington, Addison, Riverside, etc. They are all sandy loams of variable color, yellow, red, brown, and bluish-gray, and are frequently of a mottled character. Most of the clays burn to a red brick, but certain ones show a tendency to fire buff, and since these lighter burning parts are oftentimes tougher, they do not mix readily with the red-burning clay when the run of the bank ia used, so that the buff spots show in the brick after burning. At the yard of the Washington Hydraulic Pressed Brick Company, the several clays are carefully separated and burned alone, thus giving several different shades of product.
The ftvms in o[)eration in this region are: Washington Hydraulic }^r(^sed Brick Company — a view of the corapany^s plant is given in plate XXVI; Jackson-Phillips Company; Potomac Brick Company; Virginia Brick Company; Estate of Charles Ford; Walter Brick Company; West Brotliers; Alexandria Brick Company; Washington Brick and Terra Colta Company: and American Hy^rienic Brick and Tile Company. The last is located near Riverside.
mhhbal bbboubcbs of i
I
i
4
m^
, -■ r"
GLAT8. 176
The Fredericksburg Area.
The most prominent clays in the region around Fredericksburg are those belonging to the Eocene formation. While these no doubt underlie a considerable area between Fredericksburg and Stafford to the north, still prominent outcrops of them are not very abundant.
The nearest of these to Fredericksburg is located along the road from Fredericksburg to the Davis granite quarry on the hill leading up from the canal. This material, which is of a bright red color, is known, locally, as paint clay, and is said to have been used by the Indians for that pur- pose. How extensive the bed is can 6nly be determined by boring, for no outcrops of it are seen, except along the road, but there it is exposed in the ditch at the roadside for several hundred feet at least. Tests of this clay (No. 1356) are given in the appended table, facing this page.
Following the road from Fredericksburg to Stafford, there are a number of indications of bluish-white Eocene clay in the ditches along the roadside but most of these are topped bjr a heavy bed of sand. About 6 miles east of north from Fredericksburg, a heavy bepl of the clay is found on top of a ridge.
The section here involves :
Feet.
Surface sand and soil 1-2
Pink clay, laminated 12
Whitish clay 4
The pink clay (Lab. No. 1350) is distinctly stratified and in its upper part contains some scattered crusts of limonite. The physical and chemical properties of this clay are given in the table opposite this page.
The clay, although burning to a good color, is not a dense-burning one ; ^ ^act, it does not yield as tight a body as some of the Pleistocene clays. Its main use should be for common brick, pressed brick, or drain tile. The outcrop mentioned is somewhat distant from the railroad for cheap ^ploitation, but the extension of this bed should be found to the west- ward, nearer lines of transportation.
The whitish clay (Lab. No. 1352), which underlies the pink clay, is of buff-burning character and burns to a good body. It would no doubt make * good light-colored pressed brick by either the wet method repressed, or the dry-press process. Its analyses and physical tests are gi\en in the table opposite this page.
376 MINERAL RESOURCES OF VIRGINIA.
The Wilmont Area.
This is practically the only locality along the Rappahannock river where the Pleistocene clays are worked, and the quality of those developed at this point would make it seem desirable to prospect further for other deposits.
At the brick works at Wilmont the following section is exposed :
Feet.
Soil 1
Blue clay ( so-called ) 5-6
Gravelly sand (variable thickness) 6-15
Diatomaceous earth 10
Green sand clay 4
The blue clay, which is of Pleistocene age, is mixed with either the diatomaceous clay, or with clay .from another surface deposit not far dis- tant. The green sandy clay,' which is the same as that tested from Layton, lies below the level of the. jiard.' Plate? XXXV, figure 1, shows the Pleisto- cene clay overlying the diatomaceous e^arth.
Another deposit "-ol-./^istoeeBe/rfay, known as the House clay, is dug about one- fourth mile nortbeaBt I6i the brick works. Here the clay runs from 9 to 13 feet in thiclpiess and is underlain by sand. Still another deposit has been located o^ernalf mile northwest of the brick yard. Only the House clay (Lab. No. 1365) and that at the brick yard (Lab. No. 1362) were tested. Their properties are given in the table opposite page 175.
Although these clays are both surface clays, and occur in the same formation at no great distance from each other, still they are quite dis- similar in many respects.
No. 1362 is a red-burning clay which burns to a good bright color. Its air shrinkage is not excessive and its fire shrinkage is low. It con- tains some coarse grit which shows up clearly on the fractured surface of the burned bricklet. At cone 8 portions of the clay become viscous. This is not a fire clay, but it works well for brick and fireproofing.
No. 1365 is a gritty, light-burning clay which does not burn steel- hard until cone 5, and even at 8 still shows a rather high absorption. Its low air shrinkage and low tensile strength are characteristic of sandy clays. The material can be classed as a low-grade fire clay, such as is used in terra-cotta manufacture, or for boiler-setting brick. It is the most refractory of the series tested from the Coastal Plain area.
The brick works at Wilmont produce fireproofing, boiler-setting brick, and some front brick. In each case a mixture of the Pleistocene clays, or of these with diatomaceous earth, is used.
*<•
w2*
THE
^"«^'"i^
*. /
. '-£■..
CLAYS. 177
The Layton Area.
Along the shore of the Kappahannock river, about 1 mile south of Layton, there is a long outcrop of gritt}- greenish clay, of Miocene age, which is evidently part of a rather extensive deposit. The material is well shown in the river bluff, and its smooth vertical surface stands out in marked contrast to the overlying sand. 'The bed as here exposed is not less than 9 feet thick, and is overlain by 6 to 8 feet of sand, which iiiay be adapted to molding purposes. The clay (Lab. No. 1354) in table opposite page 175, evidently underlies the diatomaoeous earth which crops out farther down the river, and both are overlain by tlie sand referred to above. This same clay is seen inland from the river, behind the mill at Occupacia post-office; it also underlies the diatomaeeous earth at Wilmont, and is seen at several other, points. along the river bank.
It is exceedingly sandy, as cattiUe ji&td. py the feel, and seen from the analysis (silica, 85.72 per cent.). vlWyirinkage is very low and it burns to a very porous body, so that St would seem .undesirable to use it for even common bnck. *' ,V .•.- -'r* " '
Overlying this at Occupacia ^post-office is a whitish sandy clay (No. 1367) of table opposite page 175, which, although quite different in ap- pearance from the green clay, resembles it closely in both physical and chemical properties. One might suppose, judging from its color, that it was a fire clay, or at least semi-refractory in its character, but it is not.
The Hilf ord Area.
Along the road from Milford to Bowling Green, and about three- quarters of a mile from the former locality, there is a promising deposit of yellowish brown Pleistocene clay, 10 to 12 feet thick. The bed is under- lain by sand, but has very little overburden. Its characters are given in the table opposite page 175. (No. 1353.)
This is a red-burning surface clay, which becomes steel-hard at OS, but is too gritty to use for any purpose except common-brick manufacture. It would probably work on a dry-press machine.
The Bichmond Area.
Richmond, next to Alexandria, is the most important clay-working center in the Coastal Plain region of Virginia, there being a number of yards engaged in the manufacture of common and in some cases pressed brick. Most of these are located on the edge of Richmond and in the
178 MINERAL RESOURCES OF VIRGINIA.
suburbs of Manchester and Fulton, while a few are located near the reser- voir and race track.
The output of these is not sufficient to supply the demand, and Bome outlying towns are also drawn upon. The better grades of pressed brick in Eichmond are not made in the Coastal Plain area. Some are obtamed from Clayville, Powhatan county, Virginia, but most of them come from points outside of the State.
There are four yards in operation in Manchester, all of them being located in the vicinity of Knight and Maury streets. All of these are engaged in the manufacture of soft-mud brick and a few of them also produce a small quantity of pressed brick. The clay used is a more or less mottled, gritty, yellow or reddish clay, which ia covered by a thin layer of sandy soil and commonly imderlain by a bed of sani. At only one point, namely, the yard of Green and Harrison, is an underlying crystalline rock encountered. The clays in general are very tough and plastic, some- times quite sandy, and they contain a variable quantity of stony material which ranges in size from small pebbles up to large boulders, most of these being of crystalline character. This stony material is not found to be uniformly distributed through all the beds, but seems to run rather in streaks, the ^eatest quantity of it having been observed in the bank of W. J. Ready, and Green and Harrison.
At G. E. Redford's yard, the clay shows an average thickness of 12 feet with a maximum of 17 feet, and is underlain by a hard bed of sand and gravel. It is a mottled ^itty clay with scattered mica fragments and many limonitc stains running through it; and it contains also many decom- posed pebbles of (tryst al line rock. The clay pit is a large shallow excavation lying to the south of tiio yard and the working face has a height of from G to 8 feet. The material is red-burning, and for the manufacture of bricks the run of the bank is commonly used. This is necessary because the clay seems to vary somewhat in its physical character.
Thus, for instance, it is not safe to use that found in the north end of the pit alone, because it is very tough and cannot be used without cracking. It is mixed therefore with the more sandy portions of the bed.
Adjoining the yard of Redford on the west is that of W. B. Davis. This pit, which is a large shallow excavation, lies to the south of the yard, and has a working face of from 6 to 7 feet in height. The clay is similar to that in Red ford's bank, but seems to contain fewer stones.
Adjoining Davis' yard on the east is that of W. J. Ready. The clay
■ .".J
CLAYS. 179
pit which lies to the northwest of the yard is much deeper than the neigh- boring excavations and also lies at a slightly lower level, for the upper surface of the clay is uneven and slopes towards the river. The clay in general is somewhat similar to that found at the two preceding yards but contains more stones and boulders than are found in either Bedford's or Davis* bank. The thickness of the clay is said to be at least 18 feet, and it is probably underlain by sand. Here in a working face of perhaps 2')0 feet in length they recognize three different kinds of clay, only one of which they claim can be used alone. If either of the other two is used by itself, it results in an imperfect product. The physical and chemical characters of these three clays are given in the table opposite page 176.
A plant is also operated by W. J. Ready near the West End yard and is located a quarter of a mile west of the track near the reservoir. The ma- terial is the usual mottled surface clay which is worked to a depth of about 7 feet, although a total thickness of 20 feet is claimed for it.
The yard of the Fulton Brick Company, which is commonly spoken of as Westford's yard, is located west of the Chesapeake and Ohio Bailway round house. The clay used here is the ordinary surface clay and does not seem to run over 10 feet in thickness. It also contains many cobble stones. Underlying this is a fine sand which is at least 8 feet deep and is used for sanding the brick molds.
The Baltimore Brick Company operates two yards at Rockett, a suburb of Richmond. The yards are located near the intersection of Ohio and Williamsburg avenues. The clay is tempered in ring pits, molded by hand, and burned in dutch kilns. Some 12 years ago the company tried making soft-mud machine brick but gave it up for some unknown reason. The clay is obtained from imder the surface at several points in the vicinity of the yard and averages from 15 to 18 feet in thickness with an underbedding of sand. The material is quite similar in character to that at Manchester, but lacks the stones and boulders.
Ma3rnard and Powers operate a pit lying to the southeast of the Balti- more Brick Company's excavation. The working face here is about 12 feet high and shows a sandy, mottled, yellowish-brown and gritty clay similar to that occurring in the other pits in this vicinity. The company claims that its clay runs 20 feet in depth and is underlain by a bluish-gray Sand. The chemical and physical properties of this clay (No. 1300) are given in the table opposite page 175.
A clay very similar in appearance to that on the Ball property, 6 miles south of the city, and probably of the same age is also found outcropping
180 MINERAL RESOURCES OF VIRGINIA.
on the Williamsburg road leading to Stagg^s Mill, about one-half mile to the west of where the road crosses the railroad. The clay is exposed on a sloping hillside, and in such position that a large quantity can be removed without having to take off much overburden. It is also well located for shipment. As far as could be ascertained the bed is not less than 20 feet thick. It (Lab. No. 1330) is a grajdsh clay, which slakes slowly and works up with 27.8 per cent, water to a mass of high plasticity. Its air shrink- age, 12.6 per cent., is somewhat high; so also is the average tensile strength, namely, 300.9 pounds per square inch.
This is a very plastic clay which becomes steel-hard at cone 05. It gives a light red color up to cone OS, but at cone 1 gives an excellent dark red color. Its point of vitrification is apparently reached at about cone S, and at cone 6 it was well passed vitrification and had swelled considerably. It is not as good a clay as that described from near Bermuda Hundred (Lab. No. 1317) or Curie's Neck (Lab. No. 1314).
The Fort Lee Area.
At Fort Lee on the Chesapeake and Ohio Railway, about 2 miles south of Richmond, there is a group of yards operated, respectively, by C. H. Oliver, J. M. Davis, and the Fulton Brick Company. The general run of the clays is not unlike those used around Richmond, but none of the pits show stony material, such as is found in some of the Richmond clay banks.
The most southern of this group of yards is that of C. H. Oliver, which is located one mile west of Fort Lee. The clay here is found immediately underlying the surface and the bank shows 12 feet of clay, although the total thickness of it is said to be 20 feet. Underlying it is a pit of gravel and sand of unknown depth. For making bricks the run of the bank is used. The general physical properties of this clay (No. 1202) are given on page 176.
Adjoining Mr. Oliver's yard on the west is that of J. M. Davis. The clay used is similar to that employed at Oliver's pit described above. It i8 nolded by hand, dried on pallets, and burned in Dutch kilns. A few hundred feet up the track and on the north side of it are two yards operated by the Fulton Brick Company. The brick yard adjoins the clay bank on the west and the material is practically the same as that seen at the Davis place, but the methods used for winning the clay are more improved.
The dark-colored clays, similar to those described from south Chester, outcrop at several points around the base of Government Hill, especially alodig ihe Qovenixnent road leading down from the top of the hill, but in
0LAY8. 181
nearly every instance they are covered with too much overburden to permit of their being profitably worked.
Summary. — ^It may be well to make a comparative summary of the clays found in the Richmond area. Those found near the city, and those which are worked at Manchester, Fulton, and near the reservoir, are to be classed as good common-brick clays, which bum to a good color, and also make a fair grade of front brick when repressed. They are too gritty and stony as well as too irregular in their character to be used for drain tile, hollow blocks, or red earthenware. The methods used for working them are usually crude, and therefore the yards are of limited capacity. The manu- facturers claim, however, that owing to difficulties with labor, it is impracti- cable to use more improved methods, such as machine molding. Some also maintain that the hand-molded brick sells better on the local market.
The clays found at Fort Lee appear to be less stony and even less sandy than those occurring at Richmond, and they are susceptible of being worked by more improved methods. Of the yards located at Fort Lee one used a 8oft-mud machine, and another a stiff-mud machine. Even these clays however, are somewhat siliceous for any use other than brick, although it is probable that drain tile or hollow brick could be made from them.
Apparently the best clay in the Richmond area is that described from near Stagg^s Mill on the Williamsburg road. This is more plastic, denser burning and less sandy, than any of the clays now being worked either around Richmond or Fort Lee. The deposit being located so close to the city, as well as close to a railroad line, should be investigated by clay manu- facturers.
Large areas have already been dug over in the brick-making districts around Richmond, because the deposits are comparatively shallow, and the output of the yards has been large. Each manufacturer naturally ex- cavates the clay nearest to his yard first, so that as year after year goes by the pit face recedes, and the clay haul becomes longer and longer. As the city of Richmond and its suburbs are growing, it will not be many years before building will encroach on the brick yards, and the latter will have to be moved. Being, as it were, temporarily located, there is therefore not much inducement for establishing an extensive plant.
The Curie's Neck Area.
About 1 mile north of Curie's Neck and 6 miles south of Richmond, there are a number of exposures of clay along the road, and also on the fann on the west side of the road, at a locality pointed out by Mr. W. A.
182 MINERAL RESOURCES OF VIRGINIA.
Ball, of Richmond. This material has been usually spoken of as fullers earth, and some sample car-loads have been shipped to cotton oil factories in order to test it for bleaching purposes. The material, however, is very plastic and on inspection one would be likely to form the opinion that it was a clay suitable for the manufacture of some red-burning ware. In fact it is stated that at one time a small stoneware pottery was in operation at this point and there is considerable evidence of this in the numerous fragments of stoneware which are scattered around in the field near the farmhouse. Three samples, Nos. 1314, 1315, and 1316, were tested from this locality, the results being given in the table opposite page 175.
The Chester Area.
There are no brick yards in operation at this locality, but a number of outcrops of clay are to be seen in the railroad and trolleyroad cuts in the vicinity. None of them, however, are suited to the manufacture of brick. About 2 miles south of Chester along the Atlantic Coast line Railway there are several cuts, which show outctops of a sandy, bluish fossiliferous clay. The material is not uniform in character, certain layers being highly fossiliferous, others very sandy, and still others very plastic. The exact thickness of the deposit is not known, but from the exposures, it is evidently not less than 30 feet thick. No attempts have been made to use it.
The general characteristics of the clay may be summed up as follows: Red burning, low fire shrinkage, and low fusibility. DiflBcult to bum. It is not to be recommended for anything but common brick, and even for this purpose it should be avoided if something better can be found.
The Bermuda Hundred Area.
Much clay is exposed at a point along the railroad from Chester to Bermuda Hundred and about 1 mile from the railroad station at the latter locality. The same material is also seen in the gullies in the neighboring fields. This clay is at the same level as that which is worked at Broadway, on the Appomattox river, and it is probable that the deposit extends in that direction, but they do not belong to the same formation.
The exposures in the railroad cut show a thickness of not less than 10 feet, and a thickness of 49 feet was proved by boring in one place. Al- though the clay along the railroad track does not show much variation on inspection, it is stated that at the northeastern end it is brick clay, while at the southeastern end it is tile clay. The properties of the Imck clay (No. 1306) is given in the table opposite page 176.
x
/
MISKHAI, KKSIUHCKS <tV VII{li[\[A
I'iK- :;. — Kwiltr'- uliiy bunk iit Uromiwiiy uii llie Appuniattox river. CLAY ISANK AXl) HIUCK VAIU) ON AJ'TOMAITOX RiVER. VIRfJlNIA.
0LAY8. 183
Judging from the dense body of this material it would be worth ex- perimenting with for paving brick, or perhaps pipe. The most serious ob- jection to it is its high air and fire shrinkage.
This clay has been dug and shipped, occasionally, to the works of the Powhatan Clay Manufacturing Company, at Clayville, near Richmond.
The Petersburg Area.
There are three yards in operation near Petersburg. Two of these, operated^ respectively, by W. R. Turner, and Brister and Harrison, are located in Ettricks, across the river from Petersburg; the third, that of the Chesterfield Brick Company, is situated about 2 miles from Petersburg ^ near the line of the Petersburg-Richmond trolley road. They all make an exceUent grade of red brick. The properties of these clays are given in the appended table opposite page 175.
The clay is molded on a plunger stiff-mud machine, dried on pallets and burned in scove kilns. The local contractors state that the supply of bricks from the yards around Petersburg is entirely sufficient to meet the demand in that city.
The Broadway Area.
The only brick yard in operation at this locality is that of Keeler and Son, which is located immediately at the foot of the bluflE along the Appo- mattox river. The clay deposit lies about 75 feet above the river and the clay is being dug at a point in the terrace about 300 feet south of the yard. It is a tough, mottled material with a thickness of at least 15 feet, the upper 2 feet of which are weathered. Overlying this is about 18 inches of gravelly sand similar to that which occurs immediately under the surface throughout this region, on both sides of the river. The clay is underlain by a coarse, gravelly sand which extends down to the river level and probably below it. The pit, however, is not over 7 feet deep, plate XXV, figure 2.
The day bums steel-hard at mne 05 and at either this temperature or cone OS it makes an excellent red brick. If burned to this cone, or better still, to cone i, the material would probably make a good pressed brick.
This is an excellent red-burning clay which could probably be used for making front as well as conmion brick, provided it ia thoroughly pugged. At the present time it is utilized for making common brick and the run of the bank is used, leaving out the overburden of gravelly sand.
]84 MINERAL RESOURCES OF VIRGINIA.
The City Point Area.
The Pleistocene clays outcrop in the bluff along the James river, about one-eighth mile south of City Point landing. Their distribution is evi- dently irregular, for in the first cut of the railroad after leaving City Point, there is nothing but sand exposed, although the bottom of the cut is not as high as the upper part of the clay along the river shore. I was informed that borings made to the south of the railroad cut had revealed the presence of the clay under the surface sand. Along the shore the clay is not less than 20 feet thick, but it contains occasional streaks of sand. There is also about 4 feet of sandy overburden. No brickyard is located at this point, although the deposit is at the water's edge and the product could be easily shipped. Occasional car-load lots have, however, been dug and shipped to the smoking pipe factory at Pamplin City. As for this line of ware, a small quantity of clay will go a long way, so that the amount that has been dug has produced little impression.
The characters of the clay (No. 1339) are given in the table opposite page 175. The main advantage of it is, that it is conveniently located for shipment by rail, an advantage not possessed by most deposits along the James river.
The Sturgeon Point Area.
W. C. Mayo and Sons operate a common-brick yard at this locality. The plant is located along the river's edge at the base of the bluff, while the clay is obtained from near the top of the bluff. The section at this point
involves :
Feet.
Loam Ito 2
Clay 7 to 8
Sand 2
Mottled clay with iron streaks 9
Sand 20 to 30
Blue clay 3+
The sand mentioned in the lower part of the section extends down to the river's edge, and at that point it is underlain by a bed of dark bluish- gray, highly plastic clay, which is about 3 feet in thickness. The upper layer of clay was formerly worked and a considerable quantity of it has been dug. It was found, however, that it was so variable in its character and burning qualities that it was undesirable to use it, and consequently the raw material for the yard is now taken from the middle clay bed given in the section which yields a more uniform product.
It is claimed that this deposit of clay extends more or less continuously lor at least 12 miles back from the river.
0
CLAYS. 185
The Oldfield Area.
This locality lies about 4 miles south of Sturgeon Point and on the same side of the river. There is one yard in operation here, namely, that of the Oldfield Brick and Tile Company, plate XXI, figure 2, which is engaged in the manufacture of common brick. The clay here, as at Stur- geon Point, underlies the terrace which borders the river, plate XXI, figure 2, and the brick yard itself is located at the base of the terrace escarpment on the river's edge. It may be said that the materials under- lying the terrace consist of dense or altematmg beds of sand and clay over- burden, and an upper bed of loamy clay imderlain by a siliceous clay, whicli weathers to a whitish color acd contains many cylindrical limonite concre- tions. The upper bed has an average thickness of about 3 feet, and this is first removed and utilized for the manufacture of common brick. The under bed seems to be variable in its thickness, but where Dest exposed at the south side of the deposit and nearest to the yard, the thickness is at least 7 feet. It is imderlain by a tough sandy clay which is not used and which passes downward into a bed of loamy sand containing streaks of pebbles. The two kinds of clay are worked separately, the upper clay being used for conomon brick, and the lower clay, with the limonite concretions, known as the tile clay, being used for tile or extra hard biick, termed paving brick. A sample of each of these was tested and the tests given in the table opposite page 175.
The Belfield Area.
This town, which adjoins the better known one of Emporia, has one yard, whose product consists entirely of common brick, and which is oper- ated by Dr. Wood, of Emporia. The soil is quite sandy around Belfield, and the surface fiat, so that there are very few clay exposures. At the brick yard the clay extends nearly to the surface and averages about 5 feet deep, being bottomed on a coarse, whitish sand, which is not mixed in with the clay, as it does not seem to improve its quality. The clay burns to an excellent red color and makes a good common brick.
The Norfolk Area and Vicinity.
The cities of Norfolk, Portsmouth, and Newport News, are among the most important in the Coastal Plain area of Virginia, and in all, building operations are being carried on quite extensively. There is here conse- quently a good market for building brick, either common or pressed, and the supply is drawn from a number of points.
There are several yards in the immediate vicinity of these cities which <^eserve mention. E. W. Face and Son operate a yard on North Avenue,
186 MINERAL RE80UB0E8 OF VIRGINIA.
Atlantic City. The raw material is brought from a pit of Pleistocene clay on the Nansemond river, near Suffolk, and in its general character resem- bles that worked at the brick yards around Suffolk. It is a red-burning clay of excellent plasticity, which yields a good product for structural work. Before molding, the clay has a small quantity of fine coal mixed in with it, to help in burning, a practice somewhat unusual in the Coastal Plain area. It is molded on an end-cut auger machine, dried on hot floors, and burned in up-draft kilns with permanent side walls.
The plant of the Builders Supply Company is located on Middle street, Chesterfield Heights. The clay is a light-colored sandy material averaging about 3.5 feet in thickness. There are only a few inches of soil over it, and the clay is free from stones or shells.
6. A. Stephens' brick yard is located on the Princess Anne road near Godfrey Avenue. It is also working a surface clay, which, however, is somewhat different in its appearance from that at the preceding plant. The clay which immediately underlies the soil is a bluish-black, very stiff red-burning clay.
C. H. Phillips and Brothers operate a yard at Hampton, near Newport News, and here a reddish, sandy, surface clay is used, for making common soft-mud brick.
At Morrison, 1 mile north of the station, is the yard of the Booker Brick Company, whose product goes mostly to Norfolk. This is a shallow Pleistocene deposit, 3 to 4 feet in depth and underlain 'by sand. The ma- terial is red-burning and used only for the manufacture of common brick.
The Suffolk Area.
Four brick yards were visited at this locality, namely, those of the Standard Brick Company, Horrell and Company. Suffolk Clay Company, and West End Company.
The Standard Brick Company's yard is located about one and a half miles south of Suffolk along the Southern Railway. The surrounding re- gion is underlain by a deposit of sand, often of coarse grain and variable thickness. Somo of it might servo for molding sand, and much of it no doubt would answor for the manufacture of sand-lime brick. At the pit of the Standard Rriok Conipmy, thort^ is a little stripping to be done before ihe clay is reaoluxl. The hoii has a depth of about 6 feet, the lower two to throe U\'\ boinji a dark bluish-gray and the upper half discolored by woathoriuir. Tho lowor clay gives a harder brick but has a higher shrinkage than tho top olay.
Tbo yards of the Suffolk Clay Company, and the West End Company,
I
I
I
I
I
I
I
I
■^
CLAYS. 187
are located west of SuflEolk and on adjoining properties; in fact, the clay deposits worked at the two are probably continuous at the yard of the West End Company. The clay deposit varies from 5 to 15 feet in thickness with very little overburden. It is underlain by a bed of black sand, which in places is quite clayey, but is not mined with the brick clay. The clay has been traced horizontally for at least 200 yards, and contains few stones. No sample of this was tested. The clay is worked up in a stiflE-mud ma- chine, and dried in 24 hours in steam-heated tunnels.
At the bank of the SuflEolk Clay Company, the section shows :
Feet
Top soil 1
Yellow clay 3
Blue clay, lower foot sandy 9
Limonite sand 1
Sand 8
Blue marl 20
For brick making the run of the bank, including the sand layer, is used. The blue clay is not safe to use alone by any process of wet -molding, but it gives a harder, denser body. The properties of the brick mixture (No. 1345) and the blue clay (No. 1344) are given in the table, opposite page 175.
WESTERN VIRGINIA.
This part of the State (Mountain province, west of the Blue Ridge) no doubt contains clay resources of great value, which however are, as yet,, but little developed. Associated with the coals are many beds of shale, some of which appear very promising, but up to the present time these have been but little utilized. These different shale deposits are indeed worthy of a careful and complete investigation and, when fully developed, will no doubt become a valuable source of revenue.
References.
Fontaine, W. M. The Potomac Formation in Virginia. U. S. Geologi- cal Survey, Bulletin No. 145, 1896, 149 pages.
Hies, H. The Clays of the United States East of the Missis-
sippi Eiver. U. S. Geological Survey, Professional Paper No. 11, 1903, 298 pages.
A Preliminary Report on a Part of the Clays of Vir- ginia. (Jeological Survey of Virginia, 1906, 18.*^ pages.
Clays: Their Occurrence, Properties, and Uses with Special Reference to those of the United States. New York, 1906, 490 pages.
Rogers, Win. B. A Reprint of the Geolog}' of the Virginias. New
York, 1884, 832 pages. ^
PART III.
NON-METALLIC MINERALS.
I. ELEMENTS.
OBAFHITE.
General character, — Graphite, known also as plumbago or black lead, is a steel-gray to iron-black mineral having metallic lustre and a greasy feel. Chemically, pure graphite is composed of carbon but it is often impure from the presence of such mineral substances as those mentioned below. It is opaque and soft with a hardness of from 1 to 2, and a specific gravity varying from 2.09 to 2.23. Its most distinguishing features are its softness, greasy feel, and the property of soiling whatever it comes in contact with.
It is usually found in embedded foliated masses, scaly, or slaty, sometimes granular to compact, and at other times decidedl} earthy. It has a perfect basal cleavage similar to mica; is a conductor of electricity, and is combustible only at very high temperatures.
The variations in color, hardness, and specific gravity, noted above are due to mechanically admixed impurities, such as iron oxide, clay, silica, mica, etc. The workability of the mineral depends largely upon the character of the impurities and the extent and accessibility of the deposit.
Occurrence. — Graphite occurs principally in the crystalline metamorphic rocks, both siliceous and calcareous, as embedded masses, scales, streaks, and fine-disseminated grains. Its occurrence is most frequently noted in granitic rocks, gneiss, mica schists, and crystalline limestones. It is rather widely distributed in nature and is found in many localities, but it occurs in only a few deposits of such character as to be of economic importance.
Distribution and localities, — From the nature of the occurrence of iiraphite noted above the Virginia region in which the mineral may be foimd, is the Piedmont Plateau or the crystalline area, east of the Blue
ELEMENTS. 189
Ridge. It is rather widely distributed through the Piedmont area, occur- ring chiefly in the schists and gneisses but as yet no actual production of the mineral has been reported.
Extensive developments and preparation for mining and marketing the mineral have been in progress for some months in Albemarle and Orange counties at the mines of the Naylor-Bruoe Graphite Company. The property of this company, comprising 624 acres of land on which graphite appears, is situated at the base of the foot-hills of the Blue Ridge, partly in Albemarle, and partly in Orange county. The graphite is reported as occurring in veins which vary from 13 inches to 8 feet in width, and dipping at an angle of 45 ** E. The associated rocks are gneisses and syenites. The graphite "veins" are sharply defined from the foot- and hanging-walls by clay selvages. The graphite is of good quality and single blocks weighing several hundred pounds are easily extracted. An analysis of the crude mineral made by Proehling and Robertson, of Rich- mond, gave 76.28 per cent, of graphitic carbon. Numerous openings have been made and a plant for refining the product is in course of erection.
Near Sommerset station, in Orange county, on the Somers place, a large exposure of graphitic schist occurs, and at the same place much graphite is reported mixed with pyrite of a pyrite vein. In Louisa county, near Green Spring, specimens of graphite of considerable purity are found. Good specimens of the mineral have also been obtained on the road from Drake's Branch to Saxe's in Charlotte county. Tt is reported from near Jefferson post-office in Powhatan county.
In Amelia county, about 2.5 miles north of Amelia court-house, a small opening was made some years ago on a reported good show- ing of graphite. Because of the long standing of the opening and the resulting filling nothing could be seen at the time of my \isit in July 1906. On the Hubbard place in Nelson county, about 2 miles southwest of Roseland post-office and within a half mile of Tye river, a promising surface exposure of graphite occurs as disseminated scales in a gneiss of granitic composition. This property has not been opened hut large masses of the rock are heavily charged with graphite.
Graphite has also been reported by Professor Rogers from Buckingham county, and by Professor Dana from Loudoun county. In addition to these occurrences of graphite in Virginia, graphitic schists, which in some places are worthy of consideration, are quite freely distributed over parts of the Piedmont region. Except the mines of the Naylor-Bruce Graphite Company described above, attention given the graphite at the
190 MINERAL RESOUBOES OF VIRGIKIA.
numerous localities in the State has not progressed beyond the prospect- ing stage, and at many the only knowledge of the mineral is from surface indications.
Uses, — The uses made of graphite are numerous and varied. One of the principal uses of the miD<»ral is in the manufacture of crucibles^ retorts, and other refractory apparatus. It is also used in the manufacture of lead pencils, lubricants, stove-polish, paints, foundry-facings, glazing, elect retyping, steam-piping, etc. For some of these uses, especially the manufacture of refractory apparatus, the crystalline variety of graphite is essential, while for others the amorphous form is equally as good as the crystalline.
Beferences.
Merrill, G. P. Non-MetalUc Minerals. New York, 1904, 4-12.
Pratt, J. H. Graphite. Mineral Resources of the United States,
1904, 1167-1167.
Unsigned Graphite in Virginia. Engineering and Mining
Journal, 1906, LXXXI, 768.
3ee also the various volumes of the Mineral Industry, especially II, 1893,
335; XI, 1902, 343; XII, 1903, 183.
II. SULPHIDES AND SULPHARSENIDES.
I. PTEITE.
COKPOSITIOH AND PBOPEBTIES.
The mineral pyrite, disulphide of iron corresponding to the formula FeSj and known also as iron pyrites, occurs in sharply defined cubes and their crystallographic modifications, or in granular masses of a brassy- yellow color. When eliemically pure, pyrite contains iron, 46.6 per cent, and sulphur, 53.4 per cent. As mined, however, the ore is never chemically pure but contains admixtures of other metallic sulphides and, at times, considerable quantities of the precious metals, especially gold. Ordinarily, pyrite can be readily recognized by its hardness, color, crystalline form, and irregular fracture.
MODE OF OCCXmREHCE.
Pyrite is one of the most widely disseminated of minerals and it is found in rocks of all kinds and of all ages. It occurs as disseminated grnins through the rock mass; in contact positions between rocks
SULPHIDES AND SULPHABSEKIDES. 191
of different kinds, especially between eruptive and sedimentary masses; as irregular concretionary masses in sedimentary rocks; as fissure veins ; and as lenticular bodies, sometimes of immense size, lying conform- able, or nearly so, with the structure (foliation) of the enclosing rocks.
The worked deposits of pyrite in Louisa and Prince William counties, Virginia, are grouped under the latter occurrence, as they form huge lenses which conform »?omewhat closely to the structure of the enclosing crystal- line schists. Extending downward from the surface to approximately local water-level, the pyrite is altered by oxidation and hydration, form- ing the iron-cap or gossan of limonite, which is frequently mined as an ore of iron. The gossan of the pyrite ore-bodies in Louisa county, Virginia, was extensively mined as an ore of iron prior to the mining of the unaltered pyrite, and fumaced in the immediate locality.
DISTBIBTTTIOH AND LOCALITIES.
Pyrite has wide distribution in Virginia, it being detected either in traces or in larger amounts in nearly every formation represented in the State. Seldom is it found, however, sufBciently concentrated to yield workable bodies of ore. Thus far, only two counties are known in Vir- ginia to contain workable deposits of this mineral. These are Louisa and l*rince William counties, situated in the eastern Piedmont region. Map, figure 29, shows the principal pyrite belt in Virginia. The pyrite mines of these two counties are probably the largest and most extensively developed in the United States and the product from them constitutes more than 50 per cent, of the total output of pyrite in the United States.
OXVEBAL GEOLOGY OF THE LOUISA AND PRINCE WILLIAM COTTNTIES
PYBITE AREAS.
Character and structure of the rocks, — The belt of rocks in Louisa and Prince William counties in which the pyrite ore-bodies or lenses are enclosed shows unmistakable evidence of sedimentary origin. They were, in many places, largely limy or calcareous sediments, as evidenced by the thin bands and stringers of pure and impure limestone which appear, and by the large development of lime-bearing silicate minerals that are present.
The rocks have been extensively metamorphosed and are now thoroughly ■crystaUine schists, chiefly micaceous, with more or less hornblende and garnet developed in places. The normal rock is a mica-quartz schist where fresh and unaltered. Nearlv all varieties are to be found
MINERAL HSaOUBOES OF VIROIKIA.
SULPHIDES Am) SULPHABSENIDES.
193
including mica schists without quartz largely altered to chlorite^ quartz- sericite schists^ talcose and chloritic schists, and homblendic schists. In many places these various varieties of schist are gametiferous, in others garnet is essentially or entirely absait. The impure limestone bands carry both black lustrous folia of biotite and large fibrous crystals of green- black hornblende.
The schists are completely and thinly foliated, so much so that the straighter thin-banded ones are locally called slates. Certain varieties of the schist, especially the highly micaceous ones, are frequently more or less distinctly crinkled. In the Prince William county area, a wide belt of true slates lies a short distance to the east of the ore-bearing schist series. Darton has designated this belt of slate the Quantico slate and it marks the position of the ''fall-line'^ to the east of the Cabin Branch mine between the overlapping of the Coastal Plain sediments onto the crystalline rocks of the Piedmont region.
Fig. 30. — Plan of pyrite lenses in the Louisiana county area. a. Pyrite lens;
b. Micaceous schists.
The general strike of the schist belt is N. 10° to 20° E. In Louisa county the schists dip from 60° to 65° southeast with flatter dips shown in places. In Prince William county, at the Cabin Branch mine, the dip of the schists is to the northwest, varying from 25° to 64°. The rocks, as well as the ore-bodies, are penetrated by several well-developed sets of joints and in the Cabin Branch mine cross-faulting is observed.
THE ORE.
Oeneral character and mode of occurrence, — As mined the pyrite consists of massive-granular ore which varies in texture from very fine- to moderately coarse-grained. The very fine ore is ordinarily composed of minute irregular grains without crystal boundaries but may be admixed with much or little pyrite in distinct crystals. On the other hand, the
194
MINERAL RESOURCES OF VIRGIKIA«
coarser types of ore are made up chiefly of pyrite cubes and their crystal- lographic modifications. Some of the ore is very hard and non-friable, but much of it is quite friable, and in some mines practically all of the ore is of the latter type. Much of the ore contains little or no admixed small crystalline grains of white calcite and quartz distributed through the mass, but usually more or less of these two minerals is present, the cal- cite greatly preponderating, and nearly all gradations are traceable from much calcite and less pyrite to practically all pyrite with little or no calcite and quartz. The associated metallic minerals are mentioned below.
Fig. 31. — Plan of pyrite lenses at Sulphur mines, Louisa countj.
The ore-bodies consist of a series of lens-shaped bodies conformable to the structure of the enclosing schists. (Figures 30 and 31.) The lenses follow each other in the direction of strike, and may or may not be connected by thin and lean stringers of ore. The spacing between the ends of lenses is variable. In a few instances, a partial overlap of the lenses has been observed as shown in figure 30. The lenses vary much in size. In the Louisa county mines, they usually measure several hundred feet long (700 feet being the longest one yet known) and in thickness as much as 60 to 80 feet. At the Cabin Branch mine, in Prince William county, the maximum thickness is probably 10 feet and one lens had the enormous length of approximately 1,000 feet.
As developed by the extensive mining operations, the ore-bodies are marked in places by rolls and swells and by pinching and narrowing. In the change from flatter to steeper dips, no indication was shown of unconformity of the lenses to the structure of the enclosing rocks or suggesting a vein that unmistakably cuts the rocks.
In the Louisa county deposits, the strike of the ore-bodies is N. 10® to 20** E. with an average dip of 60° to 65° to the southeast. In several
SULPHIDEa AND eULPHABaSNIDBS.
places, measaremeiits showed dipB ae flat as 36° on the 630-foot lerel in the Arminius mine. In Prince William county, at the Cabin Branch mine, the general strike of the lenses is the same as for those of Louisa coun^, bnt the dip is toward the northwest varying from 25" to 55°.
Fig. 32. — Plan or pjrite lens, showio^ BlriuKers of pjrite ioterleaved with ■chiiiU on the hangiDg-wall. a. PyrM; b. CrTttallioe mIiUIb, chieflv mica- ceona. AmuDiuB mine, Loaisa counlj, Virgioia.
The contact between the ore-bodies and the wall-rock is usually sharply Mned but some grading into the coontry-rock by the ore is noted at thnea. Parallel interleaved thin stringers of solid ore, and of lean ore, to the large lenses characterize the walls of all the mines and are especially marked in the hanging-wall, as shown in figures 38, 33, and 36. Some post-mineral movement is shown in the ore-bodies, especially those of Loaisa county, in the highly polished and slickened-sided surfaces along some of the fracture planes.
Fig. 33.— Portion of pjrile lens in Cabin Branch mine, Prince William conntj, ■howing p7rit« ilringers int«rleBTed with RchisU on hangiDg-wall, and in- cloaarei of iheet masRMin thelens. a. P7rlte; b. Mica schist.
196
MINERAL RESOURCES OF VIROINIA.
Composition of the pyrite. — ^The following analyses will show the general character of the Louisa county pyrite:
Sulphur (S)
Iron (Fe)
Iron oxide (Fe,Og)
Iron sulphide (FeS,) . .
Silica (SiO.)
Insoluble
Sulphur trioxide (SO,) Copper (Cu) 1
Arsenic (As) j *
Zinc (Zn)
Lime (CaO) )
Magnesia (MgO) ) ' '
Per cent.
48.02
42.01
1.93
7.60
0.44 none
II Per cent.
50.00 43.00
III Per cent
46.40
6.02
none
IV Per cent.
V
Per cent.
50.00
93.80 6.20
none
49.27 43.62
4.23
1.50
0.38 1.32
I. Dr.. A. Volcker, analyst.
II. Sulphur mines reported by W. H. Adams.
III. Dr. W. H. Taylor, analyst.
IV. Charles Tennant and Company, analjrets. V. Arminius mine reported by W. H. Adams.
Adams reports that many analyses of the Louisa county pyrite ores give results from 46 per cent, to 51.5 per cent, of sulphur, copper from 0.6 per cent, to 9.72 per cent., and traces of gold and silver, but no arsenic. I am reliably informed, however, by the present management that analyses of the ore mined at present show traces of arsenic. Accord- ing to Adams, there are easily traceable quartz veins in the hanging- and foot-walls in all of the properties, which are gold-bearing to the extent of from $4.00 to $15.00 per ton; but these veins are always narrow, ranging from 3 to 7 inches in thickness.
More or less copper, usually a small fraction of 1 per cent, in the form of chalcopyrite, is invariably present, inextricably intermingled with the pyrite. This is obtained from time to time from the mine water as cement copper by precipitation upon scrap iron and is dried, screened, and barreled for market. Lead and zinc are present in traces at times and occasionally they are appreciable in small masses of the ore. The form in which these are present is mentioned below under associated minerals.
The average in sulphur content of all ore shipped from these mines ranges from 43 to 45 per cent.
Associated minerals. — The mineral species associated with the pyrite
SULPHIDES AND SULPHARSENIDES. 197
lenses or ore-bodies include both metallic and non-metallic com- pounds. Named in the order of their importance the metallic minerals are blende (zinc sulphide), chalcopyrite (copper-iron sulphide), galena (lead sulphide), pyrrhotite (magnetic iron sulphide), and magnetite (magnetic iron oxide). Some of these are only occasionally met with and are limited more to some mines than to others, failing entirely in one or two, while others are usually present to some extent in all.
The two commonest non-metallic minerals are calcite and quartz, the Bmall grains and crystals of which are intimately admixed with the crystals of pyrite, forming a more or less friable type of ore. Both minerals are occasionally met with filling fractures and cavities or vuggs in the massive-granular ore and in such cases are clearly of post-mineral forma- tion.
In addition to these two, dark green hornblende and red garnet are extensively developed in some of the mines. As a rule, these are not found to any extent in the ore-lenses proper but are usually found near the margins of the pyrite bodies in the wall-rock. Garnet was observed in every instance in the latter position, while hornblende does occur in the ore-bodies proper, but more often is found as the garnet. Garnet is less common than hornblende and in the Cabin Branch mine, in Prince William county, it is but rarely met with. It is always in perfect large and small rhombic dodecahedrons of deep red color.
In the Arminius and Sulphur mines, in Louisa county, thin layers of a grayish- white limestone occur in the walls and in places is close to the ore-body, as evidenced by masses on the dump with stringers of pyrite attached to them. This limestone is banded with the dark ferromagnesian bilicates. principally hornblende. Similar conditions are observed in the Cabin Branch mine in Prince William county. The limestone is impure, consisting of purer bands of limestone, an inch or more in thickness, interlaminated with bands of mica-schist and containing scattered crystals of hornblende.
GENESIS OF THE ORE-BODIES.
Without entering into a discussion in this volume of the evidence for or against any particular theory as to the genesis or origin of these ore-bodies, it may be stated that the facts gathered by me from a careful study of the belt strongly suggest a replacement of limestone by the sulphides. This is discussed at length by me in a paper shortly to be published elsewhere.
198 MINERAL RESOURCES OF VIROINIA.
THE LOUISA AND PRIKCE WILLIAIC COUHTIES PY&ITE DEPOSITS.
Louisa County.
Location, — The pyrite deposits of Louisa county are situated near Mineral City, fonnerly known as Tolersville, a station on the Chesapeake and Ohio Railway, and include three mines, two of which are extensively operated at present. (Map, figure 34.) The mines are located N. 20 "* E. from Mineral City at a distance of from 1.6 to 3.5 miles. Named in the order of their nearness to the station these are: the Arminius, Smithy and Sulphur mines.
The pyrite belt is crossed by the Chesapeake and Ohio Railway to the west of Mineral City and has been prospected for pyrite for a distance of 10 miles southwest of the Arminius mine, or about 8.5 miles southwest of Mineral City, Nothing, however, that seemed profitable in pyrite concentration has been found south of the railroad. A goodly number of gold mines have been worked at dififerent points in the belt.
Historical — The Louisa county pyrite mines were worked at different times for iron, copper, and pyrite. They were first opened and worked for iron in 1834 when the gossan or limonite cap, overlying the pyrite to a depth of from 40 to 60 feet, was mined for iron-making in the local furnaces. The gossan at the Arminius mine was practically exhausted in 1861, but that at the Sulphur mines was worked during the Civil War. The gossan ore mined on the Arminius property is reported to have been fumaced in the old Rough and Ready furnace, located about 1.5 miles north of Tolersville, now Mineral City; that from the Sulphur mines was fumaced in the Victoria furnace situated on the present mines property. Both of these furnaces are now entirely destroyed.
According to Adams the Arminius mine was opened for copper as early as 1847. It was operated for copper at a later date and prior to the mining of pyrite by the Virginia Central Copper Mines Company; and at a still later date, by the Arminius Copper Mine Company. The total production of copper from the Louisa coimty mines is reported as not being large, and represented chiefly ores of secondary enrichment be- neath the gossan and at the surface of the pyrite.
According to the same writer the Arminius mine was first opened for pyrite mining in 1865. It was purchased in 1865 by a New York Com- pany which worked it until 1877 for copper and pyrite. In 1883, it was purchased by W. H. Adams and was continuously worked for pyrite until June, 1894, when the present company assumed control.
SULPHIDBS AND SULPHASSEinDES.
THE ABMINIDS MINE.
ThiB mine is located about 1.5 miles N. £0° E. of Mineral City and hag been variouely worked for iron, copper, and pyrite since 1834, Pyrite mining -waa begnn at a much later date, 1805, after the working off of
Fig. 34. — Map ihowiDg location of p;rite minvt in Louiw county. Minec cated by heavj bl«ck dota; strike of schigtosilj by utovb. Based o topojp^phic ebwii, U. S. Geol. Sarrey. Scale, | inch equals 1 mil proiimatelj. Contour Interval, 50 feet.
200 MINERAL ItKSOUBCEB OF VIRGIKIA.
the iron-cap or gossan ore. The mine has been eoastantly worked for pyrite for 23 years.
The ore-bodies are quite extensive and they confonn to the Btmcture of the enclosing Bchists, with local clianges noted in both Btiike and dip of the ore-leuBes and the rock. Both hard lump and friable ore are mined, only the latter being milled, which is sold as "fine." The lump ore is cobbed but not milled. The ore is masslTe-granular, the individaal pyrite grains largely possessing crystal form, cubes and their CTyBtallographic modifications. White granular calcite is the most abundant gasgne mineral, with some quartz and less dark green hornblende.
Sphalerite, chalcopyrite and galena, named in the order of their abundance, are frequent accompaniments in small amonnts of the pyrite. Some pyrrhotite and much magnetite are admixed with the pyrite locally. The ore is reported to contain traces of arsenic, gold, and ailTer. Of the associated metalliferous minerals, only copper is saved and this only occa- sional iy.
Fig. 36. — Plan of pjrite lent oa l!20-foot IstcI, ArmiaiuB niiiie, Louiw coantj, showing FeatheriDK out at Dorth«ast end bv inlerlMTing of pjrite and Mhitt. a. Pyrite: b. Schist.
The pyrite lenses vary in size but are usnally very Urge, the largest onp yet found measuring 61 feet wide by 700 feet long. The lensei will usually average about 30 feet wide and several hundred feet long. The mine has produced large quantities of ore; is developed by 4 inclined shafts worked on more than 8 principal levels run from opposite sides of the shaft and following the direction of the lenses. The slope of the shafts will average about 63° to the southeast. Of the 4 shafts, 2 were working during the summer of 1004; No. 3 shaft which has reached a depth of S75 feet, and No. 4 shaft which has reached a depth of S50 feet The property has been extensively tested beyond the working area by much diamond drilling.
The lenses do not follow each other along an entirely straight line, bat nre off.=et Imth northeast and southwest without real overlapping, except
MIKBRAL RBSOLRCBS Ol' VluniNI
'LATE XXVII.
PYRITE MINES IN VIRGINIA.
MINERAL BESOL'RCKS Of VIKGlNtA.
I'LATE XXVIil.
|
' ' '-.;%■■ v^tV^V.i |
|
|
^B^^MK^'nc^.iiJ^Bt^''^^^ |
|
|
>. |
|
|
,1 ; |
IS Fit;, I, uliuviiiii; crvslalline seliist PYR[TK I.ENS. LOnSA COUNTV, ViRttlSlA,
SULPHIDES AND SULPHAB8ENIDE8. 201
in one or two cases. Figure 36 shows feathering out of one of the ore- bodies at the northeast end, on the 620-foot level, by interleaving of the pyrite and schist.
The surface plant of the Arminius mine, shown in plate XXVII, figure 1, is large and commodious, and is well equipped with all necessary modem machinery for the mining and milling of pyrite. The total output of ore from this mine is utilized for .the manufacture oi sulphuric acid. The average sulphur content of the ore shipped from this mine is from 43 to 44 per cent.
THE SMITH MINE.
The Smith mine, now owned by the Mining Department of the United States Fidelity and Guaranty Company of Baltimore, Maryland, is located three-quarters of a mile N. 20° E. from the Arminius mme. At the time of my visit to this mine, in the summer of 1906, operations were suspended pending litigation. The mine is reported to have been first opened about 20 years ago. It has been developed by 3 shafts and numerous drifts, the deepest being 300 feet, the other two 100 feet and more in depth. Ore has been mined on the following levels : 100, 160, 200, 250, and 300 feet.
The ore is of the friable type and of excellent quality, of which a large total output has been produced. The surface plant comprises a mill and all necessary machinery for pyrite mining and milling.
THE SULPHUR MINES.
The Sulphur mines are located 2 miles northeast of the Arminius mine and 3 miles northeast of Mineral City, a station on the Chesapeake and Ohio Railway. The mines are connected with the Chesapeake and Ohio Railway at Mineral City by a broad-gauge steam road, built in 1884. The gossan or limonite cap was first mined and furnaced prior to the Civil War in the old Victoria furnace on the present companjr's site, which was closed in 1877. Mining of pyrite was begun in 1882.
The property is developed by 8 shafts, 3 of which were working ai the time of my visit in August, 1906. The greatest depth attained in the working of these shafts is 720 feet. The method of mining the ore is closely similar to that employed at the Arminius mine.
Many old cuts are now exposed from which the gossan ore was early mined. Several of these afford opportunity for observing the ore-bodies and their relations to the enclosing rocks as shown in plate XXVIII, figures 1 and 2. Careful measurement of the direction of strike of the lens in one of the largest and longest of the old gossan cuts gave N. 20° E. and dips
202 MINERAL RESOUBOES OF VIBOIKIA.
ranging from 65"* to 76° south 20° east, with an average dip of 66®. Entire conformity with the foliation of the enclosing rocks was noted at every point where observations were made. Here, as at the Arminius mine, slight local changes in the degree of strike and dip are noted while the general direction of each remains constant.
The ore-bodies, lenses, average from 40 to 50 feet in thickness and several hundred feet in length. The old gossan cuts, which are now badly caved, confirm these dimensions. The ore-lenses on this property lie ap- parently west of those at the Arminius mine, which gives an average width of the ore-bearing schist zone in Louisa county of from 800 to 1,000 feet.
The mineral associations are the same here as at the Arminius mine. Judging from a careful examination of the dumps chalcopyrite, pyrrho- tite, and probably magnetite, are somewhat more abundant than at the Arminius mine, and calcite seems to have considerably greater develop- ment at the Sulphur mine.
Both hard and friable ore are produced, the latter existing in largest quantity. At present, only the low grade ore is milled. The milling schonc is closely similar at the two mines except at the Sulphur mines trommels and tables are used. The fine and coarse ore are separated at the tipple and all ore goes to the washer. The concentrates average 42 per cent, of sulphur. Three sizes of ore are shipped, all of which is used in the manu- facture of sulphuric acid.
The Sulphur mines surface plant is very large and commodious and is well equipped with all necessary machinery for handling the ore in the mines and at the mill. Preparations were in progress during the summer of 1906 to enlarge and otherwise improve the present mill.
Prince William County.
THE CABIN BRANCH MINE.
Only one producing pyrite mine has been developed in Prince William county. This mine, known as the Cabin Branch mine, is located about 1.5 miles northwest of Dumfries. (Map, figure 36.) Some prospecting for pyrite has been done both to the southwest and to the northeast of the Cabin Branch mine. Two small operations, separated by a distance of several miles from each other, are reported opened about 12 miles southwest of the Cabin Branch mine, in Stafford county.
The Cabin Branch mine was first opened in 1889, but it was not con- tinuously operated until several years later. It is developed by 3 shafts,
SULPHIDES AND SDLFHAHaENIDES. 303
the deepest one of which, is 1,000 feet oo an incline which Tariee from 25° to B5°, the dip of the ore-body. The ore-body is worked on all lerels from the surface to the depth of the shaft, 1,000 feet. This lens averages from 5 to 10 feet in thickness and is approximately 1,000 feet bng. Unlike the pyrite ore-bodies of Louisa connty, those developed at the Cabin Branch mine dip to the northwest willi cioss- f suiting, ordinarily of slight displacement. Yariations in dip of the lenses here are much greater than for thoBe of Louisa county. The
Fig. 3G. — Hap showiDS localion ot Cabin Branch pyrite mine, Prince William county. Mine indicated br heavf dot. Based on tbe Mt. Vernon topo- graphic Bheel, U. 8. Geol. Survej. Scale, | inch = 1 mile, approii- mabel J. Contour interval, 60 feet.
mineral associations are similar to those of the Louisa county mines. Chatcopyrite, a little pyrrhotite, and occasional galena and blende, are interraingled with the pyrite. Galena and blende are present in much smaller quantity than in the Arrainius and Sulphur mines of Louisa county. Traces of gold are reported in the pyrite. No attempt is made to sBTc any of these in the mining of pyrite at the Cabin Branch mine. Of the non-metallic minerals, calcite and quartz occur as at the other mines. Hornblende ia found, but a careful examination of the dumps showed only an occasional red garnet.
204 ICINEBAL BESOUBCEB OF VIHOINU.
The ore is closely similar to that of the Louiea county mines in general character and excellence, and similar grades of ore are marketed. The surface plant is extensive and modem and well equipped for handling the ore. Plate XXYII, figure 2, shows the Cabin Branch pjrite mine.
A narrow-gauge road is operated between the mine and Barrow Siding on the Bichmond, Fr^ericksburg and Potomac Bailway, distant about 6 miles. The company also controls its own wharf on the Potomac lint which is connected with the mine by the above narrow-gauge road and offers magnificent facilities for* ore-shipping by water.
'ZM
FiK' 37. — 'PIbh of portion of pyrite Icdb at Cabin Branch miDe, Prince WiUiMn county, Hhowing interleaved lenses nr pyritr, quarti and caldte on huiEing- wall, with minor folding. Inclosurva of quiru and caldte in pyrite lou. ThcM fill fracluraa in some cowa and are Bubiequent.
HETHODS OF mHIKQ.
The methods employed in mining the ore at the different mines is, in general, closely similar, differing only in minor details. Since the ore-bodies dip from 25° to 65° the geDcral practice is to develop them by inclined shafts sunk in the direction of dip. Levels are then run out from the shaft on the two sides in the direction of strike of the lenses and at convenient dlslancos above each other. In the Louisa county mines, Btopes are opened up by driving levels along the lens at intervals, which are connected by raises, and the ore broken down by overhand stoping- The walls are comparatively strong and but little timbering is necessarj'. At the Cabin Branch mine, in "Prince William county, the conditions are somewhat different from those at the Louisa county mines and the methods i'm|)l()yf?d differ slightly in details. At this mine,, the lenses show a greater viiriation in di[i, are eross-faulteii, and the wells are apparently softer, which require more timbering. At all the mines the ore is raised by inclimil cnl>lc and curs.
1 1,
:.ATB XXIX.
Dear Mineral City,
VHITK MINKS IN VIRGINIA.
SULPHIDES AND SULPHARSEN1DE8. 205
mixiNO.
The ore is prepared and marketed in 3 sizes, lump, spall, and fine. The lump lepresents the first grade ore as broken in the mine and is free from all date and lean material. Spall is clean limip ore broken to pass a 2.5 inch ring and is freed from finer material by screening. Fine ore is aixed to pass a %-inch screen and is usually washed or jigged to bring it up to grade. The ore is sold on a basis of sulphur content at a yariaUe price per unit.
The following description of the milling practice at the Virginia pyrite mines has been abstracted from a published paper by Painter, in the Engi- neering and Mining Journal for July, 1905. The larger part of the output from the Louisa county mines consists of the grade ^^fine'' ore. One mine turns all of its ore into "fine.** At this mine, the skip dumps upon a grizzly of railroad iron set 3 inches apart. After picking and forking the slate from the 2 sizes^ these go to their respective crushers at the head of the mill. The ore is reduced to jig size by crushing with breakers and rolls and screened by trommels, when it is fed by a distributer to the Hartz jigs. Jigging through a bed of cast-iron balls is employed, and the hutches dis- charge upon a belt^conveyor of ascending grade, which delivers to the stock piles where the ore soon drains.
At another mill the skip dumps upon a similar grizzly; the oversize is sorted into No. 1 lump for shipment. No. 2 lump to the mill, slate to the waste; the undersize falls upon a floor, where the slate is eliminated, the remainder going to the mill in a separate car by rope haulage. Usually, the better grade of lump goes to a jaw-breaker set to make spall ore, a fine-bar grizzly cutting out that under 114-iiich size, which goes to the mill. After being inspected and the slate thrown out, the spall ore is loaded in box cars. The mill is arranged to crush the ore by successive steps in Blake crusherSy roll-jaw crushers and rolls, with repeated screening to jig size. The same practice of jigging through a bed of cast-iron balls is employed ; but the jigs discharge into a de-watering device which feeds a belt-conveyor deliyering to the stock pile, bins or hearth drier, depending upon the weather. Tables are being installed to treat the overflow from the de- watering tank.
At the Cabin Branch mine, the skip dumps upon a 2.5 inch grizzly. The oversize goes to the lump-ore storage-bin, from which it is drawn off at intervals and sorted. Slate goes to the dump, first-class lump to the spalling floor and the remainder to a roll-jaw crusher at the head of the
206 MINERAL RESOURCES OF VIRGINIA.
fine-jigging annex. The No. 1 lump is all spalled by hand to burner size and forked into measuring chutes delivering to the cars. The spalling is done by hand with long-handled hammers of 2-pound weight upon a thin layer of ore on the floor. The resulting ^^fine" is small in amount and is screened into the fine bin. The undersize from the grizzly goes to a re- volving screen with 1.5-inch round holes, through which the ore is worked into the pebble-ore jig. The oversize goes to a slate-picking chute de- livering upon a spalling floor. The pebble-ore jig is a 3-compartment Hartz jig fitted with No. 2 mesh. No. 8 iron-wire screens. It discharges from the spouts, clean pebble and middling; from the hutch, clean, fine middling and waste.
The clean pebble ore is elevated to a screen delivering to a skipping chute; the small ore is returned to the roughing rolls. The dean ^^fine" ore runs into the fine bin which is heated by exhaust steam. The fine middling is elevated to the roughing rolls. After passing through rough rolls, the crushed ore meets the No. 2 lump which has passed the roll-jaw breaker, and the product from the fine-crushing centrifugal rollsy and is elevated to a 2-unit centripact screen. The upper screen is 2%-inche8 aperture, and the oversize goes to the roughing rolls; the second screen is ^-inch, and the oversize goes to the fine rolls; the through size goes to the 2-compartment fine jigs.
XTses.
Pyrite is utilized chiefiy for the manufacture of sulphuric add. It is also used in the preparation of the iron salt known as green vitriol or copperas (iron sulphate). Very small amounts of the mineral are util- ized in the preparation of Vermillion paints and occasionally for jewelry. The entire output from the Virginia mines is reported to be consumed in acid-making.
Froduction.
The total production of pyrite in the United States is distributed among less than 10 states, of which Virginia produces more than one- lialf. On this basis, the following figures which represent the annual pro- duction of pyrite in the United States will afford some idea of Virgim'a's yearly output. The production of pyrite in Virginia for the years 1904 and 1906 was 120,671 and 123,153 long tons respectively, valued at $440,- 753 and $426,008.
SULPHIDES AND SULPHABSENIDES.
207
Production of pyrite in the United States from 1882 to 1906 inclusive.
(Long tons.)
|
Year |
Quantity |
Value |
Year |
Quantity |
Value |
|
1S82 |
12,000 |
$ 72,000 |
1894 |
105,940 |
$ 363,134 |
|
1883 |
26,000 |
137,500 |
1895 |
99,549 |
322,845 |
|
1884 |
35,000 |
175.000 |
1896 |
115,483 |
320.163 |
|
1885 |
49,000 |
220,500 |
1897 |
143,201 |
391.541 |
|
1886 |
55,000 |
220,000 |
1898 |
193,364 |
593,801 |
|
1887 |
52,000 |
210,000 |
1899 |
174,734 |
543,249 |
|
1888 |
54,331 |
167,658 |
1900 |
204.615 |
749.991 |
|
1889 |
93,705 |
202,119 |
1901 |
0241,691 |
1,257,879 |
|
1890 |
99,854 |
273,745 |
1902 |
a207,874 |
947,089 |
|
1891 |
106,536 |
338,880 |
1903 |
a233.127 |
1,109,818 |
|
1892 |
109,788 |
305,191 |
1904 |
a207,081 |
814.808 |
|
1893 |
75,777 |
256.552 |
1905 i |
253,000 |
938,492 |
|
a Im |
dudes production of natural |
sulphur. |
|||
|
Beferences. |
Adams^ W. H.
Pontaine, W. M. Martyn, Wm. Merrill, G. P. Nason, P. L.
Painter, B. H.
Wendt, A. F.
The Pyrites Deposits of Louisa County, Virginia. Transactions .^erican Institute of Mining Engi- neers, 1883, XII, 527-535 ; The Virginias, 1884, V, 74, 80-81.
Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154-155.
Pyrites. Mineral Eesources of the United States. United States Geological Survey, 1883-84, 877-905.
The Non-metallic Minerals. New York, 1904, 31-37.
Origin of the Iron Pyrites Deposits in Louisa County, Virginia. Engineering and Mining Journal, 1894, LVII, 414-416.
Limestone Associated with Pyrites and Pyrrhotite of the Appalachian System. Engineering and Mining Journal, 1906, LXXXII, 172-173.
Pyrite Mining in Virginia. Engineering and Min- ing Journal 1905, LXXX, 148-149.
Pyrites Mining and Milling in Virginia. Engineer- ing and Mining Journal, 1905, LXXX, 433.
The Pyrites Deposits of the Alleghanies. Engineer- ing and Mining Journal, 1886, XLI, 407-411, 426-428, 446-447; Ibid. 1886, XLII, 4-5, 22-24; School of Mines Quariieriy, 1886, VII, 154-188, 218-235, 301-322.
208 MINERAL RESOURCES OF VIRGINIA.
2. FTBSHOTITE.
Pyrrhotite or magnetic pyrites, known also as mundic, is found in many of the crystalline or Piedmont counties of the State, but the largest concentration of this mineral vet kno^Mi is that of the "Great Gossan Lead" in Floyd, Carroll, and Grayson counties, in southwest Virginia. (Map,. figure 29.) Considerable prominence has been given to this "lead'' in past years in the mining of secondary iron and copper ores derived from the alteration of ihe original sulphides, pyrrhotite, containing some chalco- pyrite, of tlie surface portion of the vein. The importance of the '^ead'^ as an iron-producer is discussed under Iron on pages 419-421, and as a coppor-producer under Copper on pages 511-517. The general geolog}' and character of the vein are given at some length under Copper on pages 511-513, and need not be repeated hen*.
Where found in Virginia, the pyrrhotite bodies occur as lenses in the crystalline schist.-? and as well-defined veins, the best example of which is that of the "Great Gossan Load" in southwest Virginia. This '^cad," a well- (lofiiKKl vein of pyrrhotite, varying in width up to 100 feet, strikes southwest- ward from Floyd county, through Carroll into Grayson county, a distance of more than 20 miles. Map, figure 88, shows the position of the '*lead,'' and plates XXX and LXXV are views of mines located on the "lead." Further description and illustrations are given under Copper, pages 4IU- 519.
According to Moxham, an analysis of a sample of the mundic (pyrrho- tite) given as coming from the surface of the "load'' shows:
Per cent.
Sulphur 34.06
CJopper 0.8(56
Iron 63.16
FhosphoruB no trace
Manganese 0.306
Silica 2.99
Before the Betty Baker mine, located near Sylvatus, was closed down in 1900, 1,800 tons of the pyrrhotite were ahippt»d to the Southern Chemi- cal Company at Winston-Salem, North Carolina, where it was used for acid-making. The ore contained 33 per cent, of sulphur and after roast- ing carried 58 per cent, of iron.
As Moxham states, whether the large amount of snlphur in this de- posit is utilized or not, the main value will not be effectively realized until a process is developed by which the sulphur may be extracted from the ore upon a large scale, at such cost that the residue or '^lue Billy" will be available for the making of pig-iron.
'l
' I
I
.1
I
-n
J
I- I
r I.
■!■
i-
SULPHIDES AND SULPHABSENIDE8. 209
A considerable amonnt of sulphur can be driven off by pile-burning of the mnndic as is shown in the following tests given by Moxham :
Lump ore. Fine ore.
Roasted Percent. Roasted Percent.
Iron 65.50 Iron 48.99
Sulphur 7.69 Sulphur 5.51
The importance of the solution of this problem to the iron manufac- turers need hardly be pointed out, as it would yield an ore containing approximately 60 per cent, of iron, with low silica and manganese, and no phosphorus — an ideal Bessemer stock.
In recent attempts to mine the ore for copper, the percentage of copper in the output of the mines was found to be too small to permit the work- ing of the vein alone for copper. The future value of the "Gossan Lead" apparently lies mainly in the unworked iron ores and the utilization of the pyrrhotite, magnetic pyrite, for both acid- and iron-making.
An eirtensive plant, operated by the Pulaski Mining Company, has re- cently been completed at Pulaski for the purpose of utilizing the pyrrho- tite of the "Qossan Lead" for both acid- and iron-making. For supplying this plant with ore, the pyrrhotite is being inirfed on the southwest end of the *lead,*^ near Chestnut Yard, in Carroll county. Plate XXX is a ^ew of the vein opened at this point.
Beferenoes.
^yd, C. E. Utilization of the Sulphur Ores of Virginia in Mak-
ing Superphosphates. Engineering and Mining Journal, 1885, XL, 200.
The Utilization of the Iron and Copper Sulphides of Virginia, North Carolina, and Tennessee. Transac- tions American Institute of Mining Engineers, 1885-86, XIV, 81-84.
Fontaine, W. M. The Sulphuret Deposits of Virginia. The Virginias,
1882, III, 154-155.
Notes on the Geology and Mineral Resources of the Floyd, Virginia, Plateau. The Virginias, 1883, IV, 167, 178-180, 185-192; 1884, V, 8, 12.
Moxham, Edgar C. The "Great Gossan Load" of Virginia. Transactions
American Institute of Mining. Engineers, February, 1892, 6 pages.
"^tson, Thomas L. The Copper Deposits of Virginia. Engineering and
Mining Journal, 1906, LXXXII, 824-826.
^^ and Watson. The Virginia Copper Deposits. Economic Geology,
1906, I, 309-330.
210 MINERAL RESOUROES OF YIRQINIA.
3. AESENOFTBITE; HISFICKEL; OS AESENICAL PTBITES.
The mineral arsenopyrite, a double sulphide of arsenic and iron, FeAsS^ has been noted in quantity at two localities in Virginia, one of which has recently been developed and has produced some arsenic. The localities are in Bockbridge and Floyd counties.
In the extreme northeast corner of Bockbridge county, in the Blue Bidge, arsenopyrite is found in association with pyrite and cassiterite in quartz-greisen tin-bearing veins, which penetrate coarse granite and are described at some length on pages 567-577. No attempt has been made to work the arsenopyrite at this locality.
Near the summit of the Blue Bidge in Floyd county at Bewald poefc- ofBcc, about 17 miles from Christiansburg, and at an elevation of about 3.200 feet above sea-level, a series of "veins'^ (lenses) of arsenopyrite in quartz-sericite schist. occhpSj which outcrop in places on the surface. A second principal rock-type is abifltite gneiss, closely associated with the ouartz-sericito schist, but. its relations to the schist and to the ore-bodies are unknown. The principal lens is reported to be 3 feet thick at the sur- face but it widens to a thickness of 14 feet at a depth of 120 feet Numerous lenses are reported found* over a distance of some 7 miles. The location of the mine is shown on the map, figure 99.
In 1903, the United States Arsenic Mines Company of Pittsburg, Pennsylvania, capitalized at $500,000, began to exploit the Floyd county arsenopyrite deposits. A 215-foot adit was driven into the mountain side, supplemented with a 55-foot drift extending to an 8-foot "vein" of arsenopyrite, of 25 per cent, arsenic. It is estimated that the arsenic ore can be mined at a cost of 75 cents per ton. The underground workings are shown in plate XXXI, a blue-print copy of which was kindly furnished by the company.
According to a writer in the Mineral Industry for 1903, the ore as mined is conveyed to a Blake crusher, from which it passes by gravity to rolls, where it is finely pulverized. It is then charged into Howdl-White furnaces where ihe metal is volatilized, the vapors precipitated aod fuTther purified by .sublimation. The plant comprises a building 300 by 70 fast for tlie mill and furnaces, besides dwelling-houses, shop, labQntocy, oflks and other structures. Plate XXXII, figure 1, is a view of fhe millisi^ plant. Tlu> ('(|iii[)nirni consists of a l:^5-h. p. Westing^oose eB^piiBy . B Mh h. ]). boilers, 4 dynamos, a 10- by 20-inch Blake crusher, a 87«CMlt AVliite calcining furnace, a set of rolls for pulverizing, eto«
I
UIHUL BMOimCBB Oi
1^^ ^J^W YORK
PUBL/C LIBRA R?
TIOEM fOUNOAT'ONS.
.
Flu of the nudtrgnmnd 4
THE NEW YORK
PUBLIC LIBRARY
ASTOP, LFNOX AND TfLOE.N FC'JNDAT'ONS.
. 'N
\
/
/V
w
HINCBAl. KISSOURCBS OF VIKCINla.
PLATE XXXIl
AXl) MCKITI. MINKS, FT.OYD CWUNTY, VIRGlNtA.
HALIDE8. 211
The above plant for refining the product was started in October 1904, and shipped sample lots until January 1905, when the monthly capacity of the plant was increased to 90 tons of pure white arsenic. Operations at these mines are temporarily suspended at present, December, 1906.
Uses. — ^Arsenic is used in the form of arsenious oxide in dyeing, calico printing, in the manufacture of various pigments, fine-grade glassware and special enamels, in arsenical soaps, in the preparation of other salts of arsenic, and as a preservative.
Beferences.
Cowan, J. L. The Arsenic Mines at Brinton, Virginia. Engineer-
ing and Mining Journal, 1904, LXXVIII, 105-106.
Fontaine, W. M. Notes on the Sulphuret Deposits of Virginia. The
Virginias, 1882, III, 154-155.
Hotchkiss, J. Mispickel. The Virginias, 1883, IV, 168.
Stmthers, Joseph. Arsenic. Mineral Besources of the United States
for 1903, 327-334.
Unsigned. Arsenic. The Mineral Industry for 1903, XII, 19-21.
III. HALIDES.
1. HAUTE; SODIUM CHLOEIDE; OB COKHON SALT.
Salt biineB and rock salt both occur in the Holston valley in association with gypsum. The salt and gypsum deposits are confined to a narrow nor&east^oathwest valley of the North Fork of the Holston river, ex- tending from Flasterco on the southwest, to within 3 miles of Chatham Hill poBt-offioe on the northeast, a distance of about 16 miles. The interbedded salt and gjrpsum shales with beds of rock salt and gypsum are regarded as of lOaaiaaippian (Lower Carboniferous) age. The geology of the valley and its deposits is described under Oypsum on pages 327-335. A general idea of the valley may be gained from plates XXXIII and XXXIV.
In 1871, Jefferson, in his "Notes on Virginia" mentioned the occurrence cf salt brine in the Holston valley, but it was not until 1840 that rock salt was discovered. In 1840, a shaft was sunk which struck a bed of rock salt at a depth of 210 feet. This shaft was sunk with the idea of securing salt water, but as the operators had no knowledge of rock salt at that time, or at least did not appreciate its value for saturating purposes, and as the shaft was practically a dry one, they considered their efforts and money as having been wasted, because they failed to find what they started
212 MINERA.L BESOUBOES OF VIEOINIA.
after, that is salt water. The shaft was located about 200 feet up the *lick/* that is southwest of the old brick office-building in the upper eid of the valley. It is reported that this was the first discovery of a bed of rock salt in the eastern United States.
Eckel reports an anal3r8is of the rock salt as follows :
Per cent.
Sodium chloride 99.084
Calcium chloride trace
Calcium sulphate 0.446
Iron, alumina, etc 0.476
In the early '70's, operations were again begun in the bottom of the old shaft sunk in 1840, and the depth was increased about 20 feet in the bed of fine white rock salt. A drift was started from the bottom of the shaft in a due south course and continued for a distance of about 98 feet, when a second shaft was sunk from the surface down to the end of the drift, the idea being to run water down the second shaft and pump brine out of the first one. The foreman's advice was not followed and the drift was run too near the top of the rock salt, which resulted in the roof being soon dissolved, and the overlying loose rock fell in and completely blocked the drift.
The first borings for salt in this valley were in the old swampy lake- covered area near the present site of the town of Saltville, which was drained before the sinking of the wells. Mining of the rock salt has not yet been attempted, the entire salt product coming from the salt brines of the wells. The entire salt industr}' is, at present, confined to the imme- diate vicinity of Saltville, and is controlled by the Mathieson Alkali Works.
As indicated in plate XXXIII, figure 1, a large number of wells have been sunk over the area, the earliest of which were about 200 feet deep and passed through clay, gypsum, and shales. Hayden reports that 6 wells had been put down by 1842, only two of which at the time of his writing were in operation. The more recently bored wells are much deeper than the earlier ones and they show considerable variation in depth, since the beds indicate a strong dip. The average depth of the present wells is not loss than 1,000 feet, and some are 1,400 feet. These begin to strikd salt at a depth of from 250 to 300 feet, parsing through a mixture of salt shale and rock salt. The greatest depth attained in any one of the wells was 2,380 feet. There are 24 producing wells at the present time. Map, plate LII, will show the present salt-producing area.
In the early history of operations and, indeed, imtil within recent years, the product marketed was salt^ which for many years amounted to between
]jiM::tAL KKHorucKs ok viucin
■I.ATK X.\X1II.
Fig. 2. — Genernl vk-w of Siiltvillf. WiiHhiiiKinn connly, SALT WELLS ANt) SAI.TVILLK, vni<irNL\.
«. ^
^ ••
HALIDES. 1213
a half million and a million bushels of salt per year. At the present time;, no salt is made^ the brines being utilized at the Mathieson Alkali Works at Saltville for the manufacture of sodium carbonate and caustic soda. It is reported that in 1842, two establishments were producing salt, with a total annual production of about 200,000 bushels. Analyses gave:
Per cent. Per cent.
Sodium chloride 98.540 98.146
Calcium chloride .016 .034
Calcium sulphate. . . . ,-«i^ — ..^.^^^ L444..^ 1.820
• • ■ .. . V . . ; The following analyses of * the. rock .salt-, attd;' of the salt brines, the latter of which are of a very high degree of purity, show the general char- acter of the Saltville, Virginia, materlalr ^
I II
Percent. Percent.
Sodium chloride 99.084 93.05
Calcium chloride trace
^fagnesium chloride
Calcium sulphate 0.446 2.40
Magnesium sulphate 0.07
Alumina, silica, and iron 0.470 3.64
Water 0.30
I. Quoted from C. B. Hayden. n. Quoted from Thomas Raddiffe.
Analyses of brines from ScUtvUle, Virginia.
I II
Per cent. Per cent.
Sodium chloride 97.792 98.39
Calcium chloride 033
Calcium sulphate 2.17 1.22
Magnesium sulphate .39
Alumina, silica, and iron. trace
Percentage solids in brines ......... 24.60 26.40
Specific gravity 1.198
I. Quoted from C. B. Hayden. n. Quoted from G. H. Cook. ...
Analyses of the commercial salt from Saltville, Virginia.
I II III IV V VI VII VIII
Per Per Per Per Per Per Per Per cent. cent. cent. cent. cent. cent. cent. cent.
Bodhun ehloride 98.540 98.146 98.45 99.01 99.18 99.11 98.61 98.80
^Idum chloride 016 .034 .95 .20 .27 .68 1.02
Jjusneihtm diloride .20 .09 .05 .11 .27
^mm sulphate 1.444 1.820
Water .40 .70 .50 .10 .10
I tod n. Quoted from C. B. Hayden.
m to Vm indusive. Quoted from G. H. Cook.
214 MINEBAL BESOUBOES OF VIROINIA.
The Mathieson Alkali Works, — The Matliieson Alkali Works^ a cor- poration organized under the laws of the State of Virginia for the manu- facture of salt^ alkali^ and caustic soda, is located at Saltville, Smyth county, Virginia, on a branch of the Norfolk and Western Bailway. The process used is that known as the Ammonia or Solvay, a process first made a practical working success by Ernest Solvey of Liege, Belgium, and is now almost exclusively used by all manufacturers of alkali. The Mathie- son Alkali Works are not manufacturing salt at the present time, having closed down this portion of the operation in October, 1903. The manu- facture of salt, however, will probably be resumed in the near future on an extensive scale. The particular product made by this plant is, and has been from the beginning, sodium carbonate, commercially known as ''Soda Ash." This product is made in large quantities and in all of the different tests known to the trade. Caustic soda and bi-carbonate of soda are also manu- factured, the former in strengths known as 60, 70, 74, and 76.
The first product turned out of the plant was in Jime, 1896 ; three years later, June, 1898, the company began the manufacture of bi-carbonate or cooking soda. This product has been of superior merit from the start, and because of this fact, a large and growing trade has been acqxdred. Plate XXXIV, figure 1, is a general view of the plant.
The company operates its own limestone quarry (plate XLVI, figure 2), which is located about 3 miles from the plant, the stone being conveyed from the quarry by means of an aerial tramway. The following are representative analyses of limestone from this quarry:
Per cent. Per cent. Per cent. Per cent. Per cent.
Calcium carbonate... 97.03 97.03 97.15 96.96 96.73
Magnesium carbonate 1.24 1.15 0.91 1.12 1.37
Silica
Alumina V 1.04 1.57 2.00 2.00 1.80
Iron oxide
J
The Mathieson Alkali Works through their ownership of the Gastner Electrolytic Alkali Company of Niagara Falls, New York, are the largest manufacturers of bleaching powder in the United States. They are also the only large manufacturers of chemically pure caustic soda, which is produced in large quantities at the Niagara plant in connection with the manufacture of bleaching powder.
All products are handled through the firm of Arnold, HofFman and Company, Sales Agents, with offices in Providence, New York, Boston, and Philadelphia.
HINKKAL KEiiorui :):» OP Vlltlii:
M,ATK XXXIV.
FiR. 2.— Gpnetal vifw nf s.ill wells MATHIKSON ALKALI WORKS AND ^
I' 1
HALIDES. 216
BepresentiitiTe analyses of the Saltville, Virginia, salt brine made in 1906 diow the following results, expressed in grains per liter :
Sodium chloride 2»IM 286.00 291.00
Caldnin sulphate 5.18 4.71 4^1
Calcinin chloride 0.83 0.97 1 .06
Hmgneunin chloride 0.53 0.23 0.19
Badcliffe, ThcHnaa. Analysis of Saltville, Virginia, Bock Salt. The Vir- ginias, 1884, V, 138; Chemical News, Na 1038.
• •
Taylor, S. DiscoTery in Virginia of the Begular Mineral Salt
Formation. American Journal of Science, 1840, XTiT, 214-215.
Bogers, Wm. B. A Beprint of the Geology of the Virginias, New
York, 1884.
For other references on Virginia salt, see under Oypsum, page 335.
2. FLVOBITE; OB FLVORSFAB.
The mineral fluorite, known commercially as fluorspar, a fluoride of calcium (CaF,), is sparingly found associated with the ores of lead and zinc in the Cambro-Ordovician limestone of southwest Virginia^ in the same limestone in Clarke and other counties of the Valley region in north- em Virginia; in the mica mines of Amelia county; and as the principal g&ngue mineral at the zinc and lead mines in Albemarle county, near Faber, a station on the Southern Bailway.
As yet known, the occurrence in Albemarle county is the only one of fluorite in the State where the mineral is found in quantity sufficiently large to make it of commercial value. Its occurrence in Albemarle county is described in some detail on pages 542-544. It is obtained in the Albe- marle county mines as a by-product of the lead and zinc. The increasing demand for fluorite should make the Albemarle county deposit of some importance.
Uses. — The principal uses made of fluorite are in the glass trade for enameling, in the manufacture of steel and iron, and in the manufacture of chemical compoimds of fluorine.
Beferences.
Watson, Thomas L. Lead and Zinc Deposits of Virginia. Virginia Geo- logical Survey, 1905, I, 156 pages.
Lead and Zinc Deposits of the Virginia-Tennessee Re- gion. Transactions American Institute of Mining Engineers, 1905, British Columbia Meeting.
216 MINERAL RESOURCES OF VIRGINIA.
IV. OXIDES.
1. SILICA.
Quartz. — The mineral quartz, corresponding to the formula SiO, when chemically pure and easily recognized by its hardness, glassy luster, lack of cleavage, and insolubility in acids, is one of the most common and widely distributed of minerals. Quartz crystallizes in the hexagonal sys- tem, crystals of which are frequent in occurrence. Its common form is massive-granular occurring as veins in the older crystalline rocks.
Quartz has wide distribution in the State. It occurs as an essential tjonstituent of granite, gneiss, and mica schist of the crystalline area; as the dominant constituent in the sandstones, quartzites, and conglomerates of the Piedmont and Valley regions; and in the form of sand in portions of each of the three larger divisions of the State. A principal occurrence of quartz in Virginia is as a chief constituent of the numerous p^matite dikes and quartz veins penetrating the older metamorphic rocks of the crystalline or Piedmont region.
Quartz has been mined in Virginia in association with mica and feld- spar from the large pegmatite dikes near Amelia court-house, in Amelia county ; and from a bedded deposit in crystalline schists near Falls Church, in Fairfax county, where the quartz forms a hard and beautifully white, fine granular quartzite. A beautifully white and pure crystalline quartz occurs three-quarters of a mile west of Wirtz post-office, in Franklin coim- ty. Preparations are being made to mine the fine grade of white quartz sand in Catawba valley, Roanoke county, for glass manufacture.
Uses. — The purer clear grades of quartz are used to some extent for making lenses, and in dieap jewelry. Its principal uses, however, are as an abrasive, either as quartz sand or as sandpaper, and in the manufacture of pottery. The purer grades of quartz sand are used for glass manu- facture.
Chert. — Chert, known also as hornstone, a term applied to any impure flinty rock, including the jaspers, is a chalcedonic variety of silica. Chert has wide distribution in certain beds of the Shenandoah or Valley lime- stone of the Valley region, in the form of irregular nodular masses of light nearly white, red, brown, and black colors. No special use has yet been made of the Virginia chert.
BUtomaoeoQi earfh. — ^When pure, diatomaceous earth is a soft, pul- varokn^ ailioeoiUy day-like material, very fine and porous in texture.
OXIDES.
217
somewhat resembling chalk and kaolin in its physical properties^ and of white, yellow, or gray color. It is very light in weight. Its predominant siliceous character is shown in the analyses given below.
Origin and occurrence, — Deposits of diatomaceous earth are formed from the shells and tests of certain aquatic microscopic forms of plant life known as diatoms, which have the power of secreting silica in the same manner as mollusks secrete lime-carbonate! These low forms of organ- isms have a wide range of adaptability and are entirely aquatic, living both in salt and in fresh water under different conditions of depth and temperature. On the death of the organisms, the siliceous tests accumu- late on the bottom of the lake, pool, or pond which they inhabited, forming, in the course of time, beds of more or less thickness. Although formed at various geologic periods, the beds of known commercial importance of diatomaceous earth, both in America and in Europe, are of Tertiary age, a period which was apparently particularly adapted to the growth of these organisms.
When examined under the microscope, the material from these earths always shows the remains of diatoms or rather similar species, composed, principally of silica with varying amounts of water. The deposits are frequently rendered impure from the admixture of clay and at times are discolored by organic matter. The siliceous nature of diatomaceous earth is shown in the analyses given below quoted by Merrill:
Per cent.
II Per cent
III Per cent.
SUica
Alamina
Iron oxide
Lime.
Soda
Potash
Water and organic matter.
L From Lake Umbagogae, New Hampshire. n. From Morris county, New Jersey, m. From Pope's creek, Maryland.
|
80.53 5.89 1.03 0.35 |
80.66 3.84 |
|
0.58 |
|
|
12.03 |
14.01 |
81.53 3.43 3.33 2.61 1.43 1.16 6 04
An analysis of diatomaceous earth from Eichmond, Virginia, gave Mr. J. M. CabeU:
218
MINERAL RES0UB0E8 OF VIRGINIA.
Per cent.
Silica 75.86
Alumina 9.88
Ferric oxide 2.92
Lime 0.29
Magnesia 0.69
Soda 0.08
Potash 0.02
Nitrogenous matter 0.84
Water 8.37
Total 98.95
The description of the sample of earth yielding this analysis follows: "Sample was procured from the middle of the exposed bed of this earth just below the colored normal school on President Hill in Bichmond, Virginia. Without any previous treatment the specimen proved to be almost exclusively of distinguishable infusoria. It is white with a tinge of yellow and feels a little harsh."
Analyses of diatomaceous earth collected from different points in Tide- water (Coastal Plain), Virginia, by Dr. Heinrich Hies, made in the labors^ tories of the Virginia Polytechnic Institute, at Blacksburg, and published in the Clay Report, Bulletin No. II of the Virginia Survey for 1906, gave:
Per cent.
II Percent
III Per cent
Silica
Alumina
Ferric oxide . . . ,
Lime ,
Magnesia
Soda
Potash
Titanium oxide Ignition
Total
|
70.42 |
78.82 |
|
16.15 |
9.24 |
|
5.17 |
5.42 |
|
.14 |
.04 |
|
.79 |
.12 |
|
.39 |
.81 |
|
2.24 |
1.51 |
|
.44 |
.33 |
|
5.21 |
3.66 |
|
99.96 |
99.95 |
82.85 6.76 2.34
.35 1.06
.99 1.07 1.09 3.40
99.91
I.
IL III.
Weathered diatomaceous earth from 7th street, near Richmond Locomotive
Works, Richmond, Virginia. Diatomaceous earth from along the Rappahannock river, south of Layton. Diatomaceous earth from Wilmont, on the Rappahannock river.
Distribution. — The first bed of diatomaceous earth of any extent dis- covered in this country was in the Richmond, Virginia, area. It is com- monly known as the Richmond bed, the limits of which are from Herring Bay on the Chesapeake, Maryland, to Petersburg, Virginia, and probably beyond. It is not less than 30 feet in thickness, in places, though very
OXIDES. 219
impure at times. It is of Miocene age and is exposed along the numerous streams close to their crossings from the crystalline rocks onto the sedi- ments of the CJostal Plain.
In the Eocene and above it, at a depth of about 558 feet, in the deep artesian well at Fort Monroe a stratimi of diatomaceous earth was reached, which on critical examination by Samuel Wells yielded abimdant diatoms, nearly all of which were identical with those of the Eichmond bed.
The following detailed description of the Richmond bed of diatoma- ceous earth is quoted from Professor Wm. B. Rogers, in "^ Reprint of Annual Reports and Other Papers on the Geology of the Virginias,"
"The material in question [diatomaceous earth], composing a thick stratum lying between beds of sand and clay, is more or less mingled with them, particularly in the vicinity of its bounding surfaces. But through- out most of its thickness, it presents a very fine texture, admitting of being bruised by the fingers into an almost impalpable powder, and singu- larly free from gritty particles. Its colour in the present specimens is a very light grey or white, but the fragments into which it spontaneously divides at the exposed surface of the stratum often present externally a slightly ochreous tinge. It is decidedly, though sometimes indistinctly, laminated, the planes of the thin flakes or sheets being horizontal. When moistened, it displays considerable tenacity, and hence has hitherto been r^arded as a fine clay or fuller's earth.'*
"Of all its peculiarities, however, capable of being readily discovered, its great lightness is the most extraordinary and characteristic. When quite free from moisture, a pure specimen has a specific gravity of only 0.334, that is to say, only one-third the weight of water, bulk for bulk.''
"In adverting to the curious and astonishing fact of its being com- posed almost entirely of the shells and other appendages of former races of animalculffi, it was also mentioned that unlike the microscopic remains composing the chief mass of chalk or the larger fossils of our marl beds, these minute relics consist entirely of siliceous instead of calcareous mat- ter. For this reason it is, that the Leaf Tripoli, or Polir Seheifer of Bohemia, as well as other analogous Infusorial products, have so long been found valuable in giving a polish to metallic surfaces. Our Infu- sorial matter, when properly selected, is capable of being employed for this purpose vnth no less advantage, and from the trials I have made, I feel assured that when exempt from grit, it may be very usefully substi- tuted for the finer varieties of the Tripoli or rotten stone of the shops.''
220 MINERAL RESOURCES OF VIRGINIA.
"Of the minuteness of these objects, some idea may be formed from the following statements:'*
"The cylindrical bodies of the medium size are from l-300th to l-400th of an inch in length, and from l-1200th to l-1600th in width, but many fall greatly short of these dimensions."
"The rings, which are found separate in great numbers, are usually from the l-1500th to the l-2000th of an inch in diameter.*'
«
"The circular discs and convex bodies, reticulated with cells, vary from 1-lOOth to l-600th in diameter. In each of these are himdreds, and even thousands, of beautifully wrought cells. The predominance of these flattened forms appears to be the cause of the laminated texture already mentioned as exhibited by the Infusorial earth. It is obvious from these facts, that the number of such fossils comprised in each cubic inch of the material, can only be reckoned in millions or hundreds of millions, and that a bushel measure would contain a number of these skeletons and shells of former races or animalculse, far exceeding the entire population of the globe *'
"The valley of Shockoe creek, lying between Shockoe hill and Church hill, affords numerous favourable opportunities of observing the position of the Infusorial bed, and the strata with which it is associated by explora- tions along the sides of the bounding hills and the deep ravines by which, in many places, they are abruptly trenched."
"The middle of this valley is occupied by coarse gravel, rarely dis- covering any materials in situ. Beside the stream, a little to the left of the crossing of Shockoe hill Main street, as continued over towards Church hill, a patch of primary is displayed, consisting of Gneiss containing some Hornblende, and intersected by several veins of Felspar."
"At the base of Shockoe hill, a short distance up the principal ravines, the felspathic sandstones and conglomerates may be seen, forming the channels of the little rivulets flowing in these hollows, and rising, when best exposed, to a height of about five feet above the bottom of the ravine. Of course, near the outlet of the hollow, the heavy diluvium from the upper part of the hill conceals or replaces ever}'thing else, and neither the felspathic sandstone nor overlying beds can be seen, until we enter bonio depth into the ravine. We may thence trace it upwards, until, in conscMjuence of the slope of the surface, we reach a higher level than the up])C'r limit of this rock, when it disappears from view. This stratum consists of the felspathic sand in irregular layers, loosely cementing
. . /
UINKRAL KKKOriU'ES 01'' VUtlilMA.
ri.ATB XXXV,
DiATOMACKOrS KAIiTll. WII.MUNT. VIHGINIA.
OXIDES. 221
pdJJcB of Tamils dimensions from 1 to 4 or 5 inches, some of which bdoaDtg to formation I. An analogous material is still more extensively exposed in the mill race at the mill, higher up the creek, and composes the low knoll on which the mill is placed. Here we find the felspathic eandBtone in goieral much stained with ferruginous matter, overlain by m bed of very coarse conglomerate of an ochreous stain and unusual hirdncBB, Similar sandstones and conglomerates are displayed at various pointo along the margin of the stream, for a thickness of several feet above its surface.^'
**BBBtTHg upon this sandstone and conglomerate, we meet with beds of sand and sandy clay of a dark greenish and lead colour, and of a light grey, mottled with yellow, containing Sharks' teeth and Eocene Carditas, Tonitellas, Crassatellas, etc., in the form of casts, together with vague T^etabk remains in a carbonized condition. The contact of these Eocene strata with the underlying sandstone, is well displayed at numerous points.'*
The diatomaceous beds of eastern Virginia are capable of supplying an unlimited quantity of excellent material, but as yet they have received only slight attention.
During his study of the Virginia Coastal Plain clays for the Virginia Survey in 1905, Professor Heinrich Ries gave some attention to the diatomaceous beds around Richmond. The description of these beds given below is taken from Ries' clay report.
Beds of diatomaceous earth outcrop in great thickness in the embank- ment along the tracks by the Richmond Locomotive Works, as well as along the sides of the valley to the west. The general character of the earth is that of a silty, porous clay, which breaks out in irregular lumps. In places, it is traversed by vertical fissures, which are filled with limonite. Along the Rappahannock river there are long exposures of the diatoma- ceous earth. In places, it forms great bluffs of a yellowish-white color, which stand out prominently in the sunlight and can be seen for a long distance (plate XXXV, figures 1 and 2). This earth appears to be purer and lighter than that around Richmond, but still in places it passes into a clay.
Samples were collected from several localities and examined with some care. Microscopically examined they proved to be somewhat dis- appointing for the reason that most of them contained very few diatoms, and in some, which to the feel appeared like diatomeceous earth, hardly any diatoms could be found. This is due to the fact that the diatoms
2S2 MINERAL BE80UB0B8 OF VIBGINIA.
are not uniformly distributed through the deposit, but are found chiefly in certain layers. The results of the physical and chemical tests are given in the table opposite page 175.
The analyses of the earths given in the table, opposite page 175, collected from different points, show their chemical composition.
The location of the samples of the Virginia earths collected by the Pro- fessor Eies and analyzed in the laboratories of the Virginia Polytechnic Institute, is as follows:
No. 1322. W.eathered diatomaceous earth from 7th street, near Eichmond Locomotive Works, Richmond. This, after burning, closely resembles the diatomaceous earth from along the Bappa- hannock river, near Layton. It seems to be vitrified at cone 5 and at cone 8 is viscous.
No. 1323. This sample was also collected from the same locality as No. 1322, but farther from the surface. It is quite impure, and shows a high air shrinkage. It bums red and becomes steel-hard at cone 05, It is vitrified at cone 5, and nearly viscous at cone 8.
No. 1358. Diatomaceous earth from along the Rappahannock river south of Layton. This burns fairly dense at tiie higher cones, and gives a clean color, but is quite porous at the lower cones.
No. 1363. Diatomaceous earth from Wilmont. This bums to a very porous body as can be seen from the absorption figures. It has a low air and fire shrinkage.
It will be seen from an inspection of the chemical analyses (opposite page 175), that these earths show much variation in their chemical composition. All are quite siliceous, and one of them highly so. Nos. 1322 and 1323 represent the fresh and weathered parts respectively of the same bed. The weathered material is more siliceous and contains a lower quantity of fine particles and soluble substances, due probably to the leaching action of water filtering through it from the surface. The higher silica content seems also to affect its porosity and shrinkage in burning. It will also be noticed that the most siliceous one, namely. No. J 363 from Wilmont, is exceedingly porous after being burned.
Uses, — The chief use of diatomaceous earth is for polishing powders and scouring soaps. Its porous character renders it an excellent absorbent and it has been utilized to mix with nitroglycerine in the manufacture of dynamite. As a non-conductor of heat, it has been used for steam boiler packing, for wrapping steam pipes, and for fire-proof cement. It has also had a limited use in the preparation of the soluble silicate known as water-glass.
OXIDES.
223
Bailey, J. W.
Cabell, J. M. Coryell, Martin.
Hotchkiss, Jed.
Fontaine, W. M. Hies, H.
Bogers, Wm. B.
Stodder, Chas.
References.
Fossil Infusoria of Virginia and Maryland. I'he Virginias, 1881, II, 56-57; American Journal of Science, 1844, XLVIII.
Analysis of Infusorial Earth, Richmond Virginia. The Virginias, 1885, VI, 3.
Diatomaceous Sands of Richmond, Virginia. The Virginias, 1881, II, 6-7; Transactions American Institute of Mining Engineers, 1876, IV, 230-232.
The Infusorial Deposits of Virginia in the Fort Monroe, Artesian Well. The Virginias, 1882, III, 151-152.
The Artesian Well at Fort Monroe, Virginia. The Virginias, 1882, III, 18-19.
A Preliminary Report on a Part of the Clays of Vir- ginia. (Jeological Survey of Virginia, Bulletin No. II, 1906, 141-144.
Infusorial Stratum and Associated Tertiary Beds in the vicinity of Richmond, Virginia. The Virgi- nias, 1881, II, 58-59. Virginia Geological Survey Report for 1840. A Reprint of the Geology of the Virginias, 1884, 449-453.
On the Infusorial Earth from the Tertiary of Vir- ginia and Maryland, and the Geological Relations of the Strata. Boston Society of Natural History Proceedings, 1861, VII, 59-64.
Infusorial Deposits of Virginia in the Fort Monroe Artesian Well. A Reprint of the Geology of the Virginias, 1884, 733-736. The Virginias, 1882, III, 151-152.
The Fossils of the Richmond, Virginia, Infusorial Deposit. The Virginias, 1882, III, 159; Boston Society Natural History Proceedings, 1875-6, XVIli, 206-209.
2. coEvin)irH Ain) eheey.
Conindiun. — Corundum, the oxide of aluminum corresponding to the chemical formula AljOg, has been noted in two coimties in the crystal- line area, east of the Blue Ridge. These are Louisa and Patrick. From the first of these, Louisa county, a large deep blue crystal of corundum was found some years ago by Mr. Louis Zimmer, in the soil, but the exact locality is not known.
224 MINERAL RESOUBGES OF VIRGINIA.
Genth has described the occurrence of comndmn in Patrick county, about 2 miles from Stuart, the county-seat, in mica schists on a knob of Bull Mountain. The mica schists are partly gametiferous, and are inter- sected by granite. The corundum is found associated with andalusite, kyanite, chloritoid, and mica, in rough crystals and nodules up to 1 inch in length and half an inch in diameter. In color, it is grayish-white to white and colorless. It also occurs in finely divided microscopic grainB in the mass of associated minerals. According to Pratt, the corundum' of this locality is readily cleaned, and tests made for the cleaned product show that it is well adapted for the manufacture of the vitrified wheel.
Emery. — Emery, a granular corundum of black or grayiah-black color, and containing intimately admixed magnetite or hematite, is found in considerable quantity about 1% miles west of Whittle station on the Southern Railway, in Pittsylvania county. It is found on the land of Keatts, Craddock, Hargrave, Nance and Yeates, but the only place where any attempt has been made to exploit it, is on the Keatts farm. Two openings about 300 feet apart and 20 feet deep have been made on apparently parallel "veins." Numerous smaller openings are made nearby. The rocks enclosing the emery are probably altered amphibolites or pyroxenites.
Miller describes the emery from the Pittsylvania locality as a black crystalline mass, magnetic, polar; with a specific gravity of 4.205, and a hardness of 8. An analysis of the emery gave Miller :
Per cent.
Alumina 56.74
Ferric oxide 15.50
Ferrous oxide 20.77
Silica 0.68
Titanic oxide 1.86
Soda 3.96
Uses. — The principal use made of corundum is as an abrasive. The ruby and sapphire corundums are highly prized as gems.
Eeferences.
Genth, F. A. Contributions to Mineralogy. On a New Occurrence
of Corundum in Patrick County, Virginia. Amer- ican Journal of Science, 1890, XXXIX (3. s), 47-49.
Miller, W. W.,"Jr. Analysis of Emery from Virginia. American Chemi- cal Journal, 1900, XXII, 212-213.
Pratt, J. H. Corundum and Its Occurrences and Distribution in
the United States. U. S. Geological Survey, Bulletin No. 269, 1906.
OXIDES. 225
3. OCHEB.
DEFINITION AND PR0PEETIE8.
As ordinarily used, the term ocher is applied to the earthy and pulveru- lent forms of the minerals, hematite and limonite (the anhydrous and hydrous oxides of iron, respectively), which are almost invariably rendered more or less impure through the presence of other metallic oxides and argillaceous or clayey matter. Ocher rarely occurs in nature sufficiently pure for immediate use, and it is usually necessary to prepare it by wash- ing and grinding in order to free it from the common impurities.
Natural ochers show a variety of colors which depend in general upon chemical composition. Thus the hematites usually give ochers of red color, while the limonites give yellow or brown; each of these colors being subject to shade variations according to the amount and kind of impurities. More directly the natural colors of ocher depend on the degree of hydration and oxidation and the kind and amount of impurities. Both the red, yellow, and brown ochers are found in Virginia. According to their natural colors or sources, various varieties of ocher are distinguished.
ORIGIN AND OCCimRENCE.
The wide variation in the mode of occurrence of ocher in different localities indicates similar variation in its origin. Ocher may result from the leaching action of percolating waters and subsequent deposition; as residual products, formed by the removal on solution of the soluble parts of the original rock leaving the insoluble portions, clay and iron oxide, to form the different ochreous colored clays ; from the decomposition of rocks rich in iron-bearing silicate minerals ; from the oxidation of pyrite ; from the alteration or decomposition of hematite; and from the alteration of the more compact forms of limonite. Lastly, as in the Cartersville district, Georgia, ocher may result from the molecular replacement of the rock in which the deposits are found.
DISTRIBXTTION AND LOCALITIES.
Ocher of more or less purity is found, and to some extent has been mined, in each of the principal geologic divisions of the State, namely, the Coastal Plain, the Piedmont Plateau, and the Valley region. It has been mined at the following localities in Virginia: In the extreme eastern part of Chesterfield county, near Bermuda Hundred, on the Appo- mattox river; in the Little Catoctin Mountain, near Leesburg in Loudoun
226 MINERAL RESOURCES OF VIRGIN I A.
county; near Bedford City in Bedford county; in the vicinity of Marks- ville, in Page county; near Keezletown, in Bockinghain county; from the western base of the Southwest Massanutten Mountain; and in Page and fioddngham counties along Naked creek^ about 5 miles southeast of Shenandoah station on the Norfolk and Western Eailway.
In addition to these^ equally as good ocher deposits are found rather widely distributed over parts of the Valley and Piedinont regions, and lo some extent the Coastal Plain, which have not been worked. In the Valley and Piedmont regions, the ocher deposits are frequently more or less closely associated with beds of iron ore. Deposits of ocher which vary from red, yellow, and brown in color, and which seem particularly promising but not yet developed, are foimd in Campbell and Bedford counties; near Bon Air, in Chesterfield county; near Fairfield, in Kock- bridge county; near Waynesboro, in Augusta county; and near Bearing Run, in Craig coimty.
In his '^Reprint of the Virginias/' page 49, Professor Itogers states that occasional layers of a beautiful yellow ocher are foimd with the beds of argillaceous clay of the Miocene in Tidewater, Virginia; and again on page 54, in the Miocene beds exposed along the Pamunkey river rests a thin ochreous clay as brilliant in. its tint as the first chrome yellow. This ocher is of the most impalpable texture when dried, and would be found very valuable in coloring.
In Buckingham county, on Stonewall creek, near the Ross furnace, yellow ocher is reported by Professor Rogers in association with beds of iron ore, which occur in the micaceous and talcose schists. Also, it is found in similar association and traced for many miles sonthwwtward from the furnace near New Canton.
DESCRIPTION OF LNDlVinUAL DEPOSITS.
Chesterfield County.
In the extreme eastern part of Chesterfield county, near Bermuda Hundred on the Appomattox river, an excellent grade of yellow ocher has been extensively mined. This bed of ocher is associated with the Tertiar.* clays and sands of the Coastal Plain.
The property was purchased in 1872 by the Bermuda Ocher Company of New York, which had an investment in the enterprise of $60,000.00 and employed a force of 40 men. The product was offered on the market in 1872 at 2^4 cents per pound in competition with the Rochelle ocher which was selling at 3% cents per pound. The effect of this competition
OXIDES. 227
was to further reduce the price of both ochers, that of the Rochelle ocher to V/^ cents per pound in large lots, and that of the Bennuda ocher to 1% cents per pound. The consumers freely admitted their preference for Bermuda ocher yet they insisted that it should be sold at a less price than the foreign article.
Volume XV of the Tenth Census for 1880, page 844, states that the Bermuda Ocher Company^s mine produced in that year, 1,000 tons of ocher valued at $22,000.00 ; that the total number of hands employed was 30, and the total amount paid in wages was $10,500.00.
A writer in the Mineral Eesources for 1885 says: ''The crude ochre is washed, dried, and then ground into an article which in fineness of quality and in adaptation to all the purposes for which a light-yellow cchre is used, is unexcelled by that from any other deposit known in this country. Three grades are made, all of the same tint but of different degrees of fineness, namely, single washed, double washed, and extra floated. At the shipping point in Virginia these grades have a value, respectively, of $18, $21, and $27 per ton.'*
Loudoun County.
B^inning about 1 mile north of Leesburg, in Loudoun county, and traced for a distance of about 3 miles northward, ocher has been found at numerous points along the eastern base of Catoctin Mountain. Keith mapped and described these deposits in 1894 in the Harper^s Ferry folio of the United States (Jeologic Atlas. He says :
^'Ocher has recently been found at several points along the eastern base of the Catoctin Mountain in connection with the surface wash. The deposits occur beneath the surface of the peneplain at an elevation of about 350 feet. They are usually covered by a bed of gravel and sand from 2 to 8 feet thick, and lie under the bottoms and slopes where the mountain streams deposit their load of sand and gravel. The ocher appears to represent the iron taken in solution from the Catoctin schist and precipitated where it encounters calcareous solutions from the Newark conglomerate.
"The ocher thus far prospected is very fine and free from impurities. After the lighter part has been floated off, the small residue consists of grains of magnetite, ferric hydrate, and sand. The particles floated off are ferric hydrate and hydrates of alumina and magnesia. The natural colors of the ocher range from yellow into orange and gray; when mixed with oil, they change materially and give a great variety of reds, yellows, browns, and greens.
228 MINERAL RESOURCES OF VIRGINIA.
"In the same basins with the ocher, beds of reddle are developed, chiefly in the eastern part of the other areas. These are less unctious than the ocher, but very fine and tenacious. They are reddish-brown, and become darker when mixed with oil.
"The amount of the ocher deposits is apparently very great, though they have not been prospected over a wide area. Inasmuch as the Btreams and bottoms along Catoctin Mountain are similar to those already ex- plored, it seems quite likely that most of them will be found to contain ocher. The depth of the ocher in the larger areas exceeds 30 feet.*'
Page County.
About 3 miles south of the village of Marksville, in Page county, and near the western base of the Blue Ridge, where the Shenandoah Valley Railway crosses Stony Run, ocher has been mined for some years. The Oxford Ocher Company of Detroit, Michigan, begun operations here on 30 acres of land, located on Stony Run, where the ocher was exposed in the bluffs along the stream. The company subsequently added 20 more acres. A plant for milling and preparing the ocher for market was built and, in 1876, 200 tons of ground ocher were shipped.
In 1877, the production amounted to 350 tons, and since then, about 1,000 tons per year have been produced. During the early years of mining, the product was hauled 18 miles in wagons to New Market and shipped over the Baltimore and Ohio Railway. Since then the ocher has been shipped from a nearer station on the Shenandoah Valley Railway.
The ocher is of very light brown color and occurs in the iron-bearing shales of Formation No. I, the Primordial (Cambrian) of Rogers. The deposit is an extensive one, as all the wells sunk between the company's mine and Marksville have gone through the ocher. It is of good quality and finds a ready sale.
Excellent ocher in the same geological horizon is reported further southwest along the western base of the Blue Ridge. According to Volume XV of the Tenth Census for 1880, 875 tons of ocher were produced in 1880, valued at $82,500.00. These mines are producing at present.
According to the Mineral Resources of the United States for 1885, an analysis of the ocher mined near Marksville in Page county, Virginia,
gave: Per cent.
Iron peroxide 39.00
Alumina 16.00
Silica 33.00
Alkalies 50
Water 11.50
IMml 99.00
OXIDES. 229
Roddngham County.
Along Naked creek, about 5 miles southwest of Shenandoah Station c»n the Norfolk and Western Eailway, ocher occurs and has been mined, partly in Rockingham, and partly in Page county. The ocher occurs in the Potsdam (Cambrian) in close association with the brown iron ores worked by the Shenandoah Iron Company. The ocher beds are cut across by Naked creek which marks the boundary between the two counties. On the William Merica place in Rockingham county, both yellow- and orange- colored ochers occur. The ocher was first opened by the Virginia Mining and Manufacturing Company of Alexandria, and it was proposed that the crude ocher be shipped to Alexandria to be ground and prepared for market.
According to Volume XV of the Tenth Census for 1880, page 44, the production for the year 1880 was 112 tons, valued at $2,240.00.
Near Keezletown, in the same county and near the western base of Massanutten Mountain, brown ocher has been mined. The ocher at this locality was first operated by French, Richards and Company of Phila- delphia. The ocher occurs near the contact of the Valley or Shenandoah limestone of Cambro-Ordovician age and the Hudson River slates of Ordo- vician age. It is of very fine texture, of brown color, and good body. An analysis by Professor J. L. Campbell dried at 212° F. gave:
Per cent.
Ferric oxide 52.28
Manganese oxide 1.16
Clay with some Band 40.22
Water combined 6.35
Specific gravity 2.82
Augusta County.
Professor Fontaine has described in some detail the occurrence of several kinds of different-colored ochers on the Samuel Steele place, 2.5 miles a little northwest from the town of Waynesboro. The ocher occurs in the Shenandoah limestone of Cambro-Ordovician age, which rock is penetrated by a dike of diabase trending northeast-southwest and traceable for a considerable distance. Professor Fontaine says:
"A band of yellowish clay runs through Mr. Steele's land in a N. E. and S. W. direction following the strike of the strata as it seems, and forming apparently one of the more decomposable argillaceous layers interstrati- fied with the limestone. The limestone next to this is, in places, ver}'
230 MINERAL RESOURCES OF VIRGINIA.
cherty and seems to have been disturbed. The clay is associated with a peculiar yellowish, to dark brown rock, that graduates from a nearly pure compact silica to an umber or ocher. Near Mr. Steele's house and for a short distance to the S. W., the rock is very siliceous and is accompanied by a dark to black wad of impalpably fine texture. This material seems to be composed of very fine manganese powder, clay, and iron, with some graphite. The manganese and graphite give its character to the rock. Sometimes it is purplish in spots, but the most of the mass is nearly black, or a very dark brown. It has a soapy or greasy feel, and clings most tenaciously to any object touched by it. The deposit of wad varies from 10-30 feet in thickness, and in length has been proved for several hundred yards, while in depth, the excavations show that it descends more than 30 feet. There is clearly an immense supply of it. Frequently lumps
cf manganese are found in it, sometimes as large as one^s first The wad
has been tried as a fireproof paint on boilers, and is reported to act finely. It mixes well with oil, and has so much "body,^' that little white lead is needed to mix with it: From all that I could see I consider this to be a valuable material, and I am surprised that it has not been utilized.
"A little to the N. E. of the deposit of wad, and apparently in the prolongation of it, we find no longer the wad, but the siliceous rock has become argillaceous, and decayed to a handsome ocher. This varies from a rich yellow to a dark brown. The dark brown ocher makes up much the larger part of the deposit. There are two beds of it lying in clay. The upper one shows a thickness of about 2 feet, and is separated from the lower one which is 3-4 feet thick, by 3 feet of clay. Some of this ocher is firm and looks like a rock, but it may be easily crushed. The yellow ocher occurs replacing a portion of the brown. Both of these appear to be suited for paint. This deposit of ocher appears to continue some distance to the N. E. and S. W. I was informed by Mr. W. B. Alexander that at Red Bank, about 7 miles N. E. of Waynesboro, and on a line bearing 40° E. of N. from Mr. Steele's place, similar brown and yellow ochers occur. Fauber's umber mine occurs some 4 miles to the S. W., in the prolongation of this line of deposits, and is, I think, the same material. There is little doubt that a series of ochers of various colors and excellent quality could be selected along the outcrops of this material. All of the ores and ochers thus far described, lie within a short distance of the Chesapeake and Ohio Railway, and the Shenandoah Valley Rail- way.*'
OXIDES. 231
Sockbridge Connty.
According to Professor Fontaine, red ocher of good quality is found a half mile from the village of Fairfield in Rockbridge coimty. He describes it as being very fine-grained, rather firm in texture, decidedly gritty in feel, and most tenacious in its coloring properties. It is found on the land of Major DeVines and is reported in large quantity but has not been developed.
Warren County.
In Warren county, about a half mile east of the Shenandoah Railway, umber has been opened up near Major OveralFs house. Tests are reported to have indicated an excellent grade of material. McCreath gives the
following chemical analysis of it:
Per cent.
SUica 31.640
Alumina 13.510
Ferric oxide 34.000
Manganese seaquioxide 6.209
Lime 720
Magnesia 1.657
Alkalies and undetermined .... 3.390 Water 8.870
McCreath reports about 100 tons of the umber shipped to Pennsyl- vania markets prior to 1884.
TTses.
The principal use of ocher is in the manufacture of paints for ex- teriors of buildings, the rolling stock of railways, bridges and metal roofing. They are used as a pigment for coloring mortars and in the manufacture of linoleums and oil-cloths. They have been used to produce desirable colors in earthem ware when mixed with a certain proportion of manganese oxide. In addition to these, there are certain minor very limited uses made of ocher.
References.
Fontaine, W. M. Notes on the Mineral Deposits of Certain Localities
on the Western Part of the Blue Eidge. The Virginias, 1883, IV, 45-46; 58.
Hotchkiss, Jed. Hamilton's Metallic Paint. The Virsrinias, 1880,
I, 33.
The Oxford Ocher Companv. The Virginias. 1880, I, 173.
The Bermuda Ocher Companv. The Virginias, 1882, III, 145.
232 MINERAL RESOURCES OF VIRGINIA.
Keith, Arthur. Geologic Atlas of the United States. Harper's Ferry
Folio. U. S. Geological Survey, 1894.
Prime, Frederick, Jr. The Mineral Eesources of the Page Valley. The
Virginias, 1880, I, 35-36.
Rogers, W. B. A Beprint of the Geology of the Virginias, 1884, 49,
54, 311.
4. TTiMENITE ; HENACCANITE; OE TITAinC ntOH.
Ilmenite or menaccanite, known as titanic iron ore, is an opaque, iron black mineral, having submetallic luster and differing from mag- netite, which it re.s4^'nibles, by its crystalline form and weak magnetic properties.
The mineral occurs in granular form admixed with white apatite in extensive dike-like masses near Roseland and Bryant, in Nelson county, and about 4 miles east of Roanoke, in Roanoke county. The rock occur- ring at the above localities and composed of the two minerals, apatite and ilmenite, is described at more length under Phosphates, on pages 300-302. For location of the Nelson county ilmenite deposit, see map, figure 38.
The mineral ilmenite though abundant and cheap has as yet proved of little economic importance. Should the mineral iind an extensive use in the future, the Virginia localities noted above will prove to be of con- siderable commercial importance.
5. EIITILE.
GENERAL PROPEKTIES AHD OCCURREHCE.
Entile is a titanium oxide corresponding to the formula TiOj and con- taining theoretically 60 }ht cent, of titanium. It has a hardness of 6 to 6.5; specific gravity 4.18 to 4.25; metallic adamantine luster, and is generally opaque, rarely transparent. Its usual color is reddish-brown to red and it is insoluble in acids and is infusible. It occurs chiefly in the older crystalline granitic rocks, schists and gneisses, but it is also found in niotiiniorphic limestones and dolomites.
DISTRIBXmOH.
The only locality in Virginia and indeed in the southeast Atlantic states where rutile has been mined is near Roseland, Nelson county, about T miles northwest from Arrington, a station on the Southern Railway. ( Map. figure :^8. ) The de]>osit lies on both sides of Tye river near
Itoeeland poBt^<^ce, and is owned and operated by the American Rutile Company. The entire limiis ol the deposit are yet unknown but comprise sereral hundred acres at least on both sides of the river. The country rock is a pronounced foliated gneiss, penetrated by an occasional diabase dike.
Nelsonite Hg^ Rutile
rig. 38.— Hi
ooBDty. „ ,
mite. Contour intsTTil, 600 feet
•■ - ■ '.'■>. r-rr.Ar-- — -r.i; •;;: - - - riATTZ- TLfr "ZiiiaDa"
'■ ■■■-.= •; . '-r.-' . - -'-.■.- .;.t.*i- n -stw-siuLi. sec I
■ ■ •' . . .• ff.t.ih-'.vv. , r-.oT iTui vcur- m^r x '.1=
I I •■../: I -^ .-..-• \: . TTn ^flWBT«-TPT»nig. aH-
■ •.«•« j/".-.ti ,- :) !.^ "r**.. '. . .-.:.: "'.-^ i" " J-5 TI • . » .i ■.! I •!•■ •.tnitiJkilv
tf f J/» >U4r385l
.: 4.C.- .J .■ ■■•'.-»:• I'"- "he TT^ "Li"^*^
1. . . t .■•■^f. vr /M.n^j 750 pfmncb *?.'.::.
. :■. .•■.:...;.■. •< '»r -.'•» in4»s Til ii;i.*.- ;::-.-
. • -t . '•- .. ..-■. ■•-r A.^norlina ■ "h=
.... : vv^. ...■;: ■.■ "'. ^^ >' :'.#>r iftcr. ritiit*. T^:-
; ..■..,*•.. : ■ ^r. : ■.;i.:ici*ri '.n ioiibie *ni':s jl
:;-....■.: ■:.-;! /^ U^iTv, 00 to 33 pcT ^"^nr.
m
■ ;'., .i .-•. ,".\. l.fi. ■':■: I' or t.hr: pr^aent uses mar- ::
MIN'EUAL KBSOURCBB OF VIHOiNIA.
1-I,ATE SXXVI.
Fig. 2. — Same as Fig. I, bill Inken from a ditTerpnl (iliicc in the area. HlTirK OPKXiXfiS. ItOSKI..\Xl), SKI.SOX COl'STY. VIRGINIA.
• ■ • >
I . ■
4 ,
OXIDES.
235
alloys and certain grades of steely for the manufacture of artificial teeth^ and of porcelain ware, serving in both as a pigment. Up to the present time, the demand for rutile in the United States has not exceeded 200 to 300 pounds annually. The Nelson county plant is capable of producing from 1,000 to 2,000 pounds per day.
References.
Merrill, G. P. Rutile Mining in Virginia. Engineering and Mining
Journal, 1902, LXXIII, 351; Science, 1902, XV, 389.
The Non-Metallic . Minerals : Their Occurrence and
Uses. New York, 1904, 109-110.
Snelling, W. 0. Titanium Ores. Mineral Resources, U. S. Geological
Survey, 1901, 271-278 ; Virginia, 277-278.
Watson, Thomas L. On the Occurrence of Butile in Virginia. Economic
Geology, 1907, II, 493-504.
6. MANGANESE OXIDES.
IKTRODirCTIOH.
Elementary manganese is found in nature in the form of oxides, car- ])onates, and silicates. Of these, only the oxides are of importance in Vir- ginia. The principal known oxides are, pyrolusite, (MnOj) ; psilomelane, (H^MnOg) ; hausmannite (MnO-MuaOg) ; braunite (SMnjOg.MnSiOg) ; polianite (MnOj); niaDganite (MnjOg.HjO) ; and wad, probably an impure earthy form of psilomelane. Except when well crystallized, it is often diflBcult to discriminate between the different oxides, as they are found admixed in nearly all proportions. Usually the well-defined species can be separated from one another by their physical and chemical properties as tabulated below :
|
Species |
Hardness |
Specific gravitjr |
|
Pyrolosite.... |
2-2.6 |
4.73-4.86 |
|
Prilomelane.. |
5-6 |
3.7 -4.7 |
|
Mtngtnite... |
4 |
4.2-4.4 |
|
Polianite |
6-6.6 |
4.99 |
|
Bfiimito... |
6-6.6 |
4.76-4.82 |
|
Bamnunnite |
5-6.5 |
4.856 |
Color
Iron black to steel
gray Iron black to dark
steel gray Dark steel gray to
iron black Light steel gray
Brownish black to
steel gray Brownish black
Streak
Black or bluish
black Brownish black
Reddish brown to
nearly black Black
Same as color
Chestnut brown
Anhydrous or hydrous
Anhydrous
Hydrous
Hydrous
Anhydrous
Anhydrous
Anhydrous
238 MINEILVL RESOURCES OF VIRGINIA.
separated, but they usually occur admixed in varying proportions. Tbe ore is usually partially or entirely crystalline, of a dark steel-blue color, and the nodular type, which prevails nearly always, displays the complete or partially layered or concentric structure of concretionary masses.
THE COASTAL PLAIN REGION.
Manganese has been found in small pockets at several localities in the Virginia Coastal Plain area. Near City Point, in Prince George county, a deposit of manganese was worked which produced some hundreds of tons of ore before it was exhausted. Other deposits are reported to have been worked. It is not improbable that other deposits of small extent and similar to those mentioned above will be found in parts of the Coastal Plain area, but deposits of the extent of some of those worked in the Piedmont and Valley provinces of the State, cannot be expected in the Coastal Plain area.
THE PIEDXONT REGION.
Introduction.
The rocks of this area are crystalline schists, gneisses, and granites. They are derived in part from original sedimentary, and in part from original igneous, masses, by metamorphism. Manganese-bearing minerals, principally silicates, frequently enter into the composition of the meta- morphic crystalline rocks of the Piedmont region which, when broken down by atmospheric decay, the manganese is liberated in simpler chemical form, usually the oxide, and is concentrated in the residual clays derived from the rocks through chemical and physical means, sufficient to afford workable deposits of manganese.
Because of the widespread occurrence throughout Piedmont Virginia, of rocks composed in part of manganese-bearing minerals, manganese is likely to exist, to some extent, in the residual clays derived from these rocks over much of the area, but not necessarily in sufficient quantity and concentration to be always workable. Workable deposits of manganese ores of good quality are found in the following counties of the Virginia Piedmont province: Albemarle, Amherst, Appomattox, Buckingham. Campbell, Nelson. Pittsylvania, and Spottsylvania. In some of these, mines yielding a larp^e production of manganese ores have been operated for many years.
OXIDES. 239
DESCBXPTIOV OF IHDIYID1TAL ABEA8.
Amherst County.
At Stapleton Mills in the southern part of Amherst county a manga- niferous iron ore is found, which has been mined only to a limited extent. As indicated by the analysis below the quality of this ore is such that the deposit merits more serious consideration than it has apparently had. The quality of the ore is shown in the following analysis quoted by Weeks in the Mineral Resources of the United States for 1885.
Per cent.
Manganese (metallic) 34.56
Iron (metallic) 22.67
Phosphorus 08
Another deposit of manganese is reported from Walker's Ford Station, in Amherst county, but, so far as known, it has not been developed,
Appomattox County.
Deposits of good manganese ores are known to occur in Appomattox
county, but, so far as the writer is aware, they have received little or no
attention. Southeast of Mount Athos in the vicinity of Concord, several
recent openings have been made exposing good ore. Froehling and
Bobertson report the following results on analysis of two samples of ore
from these openings:
I II
Per cent. Per cent.
Manganese (metallic) 66.60 52.92
Iron (metallic) 28 2.53
Phosphorus 174 .002
Silica 99 10.53
Buckingham County.
Deposits of manganese ores are reported in Buckingham county in the vicinity of Willis Mountain and Spiers Mountain. No developments have been made, but good surface indications are present in these localities.
Campbell County.
In the northeastern and the middle western portions of Campbell <'ounty, near Mount Athos, Evington, and Lynches to the east and soutii of Lynchburg, respectively, large deposits of manganese ores have been worked for many years. The principal mines operated in the county are
240 MINERAL RESOURCES OF VIRGINIA.
the Piedmont Manganese Company's mine (formerly known as the Lemer mine) and the Leets mine near Mount Athos, the Saunders mine near Evington, and the Bishop mine near Lynches. In 1883, a small pocket of manganese ore was opened at Leesville in the vicinity of Lynches, which is reported to have yielded about 30 tons of ore. Prospecting for manganese ore has been in progress during the year near Lynchburg and Evington, with encouraging results at both places, and preparations are now being made to mine the ores.
The Lrets mine is located about 7 miles east of Lynchburg and about 1.5 miles south of Mount Athos, a station on the James river at the cross- ing of the Norfolk and Western and the Chesapeake and Ohio railroads. Its production of high grade ores has been very large, probably rank- ing next to the Crimora mines, in Augusta county, in quality and quantity of ore produced. The ore is of the nodular or kidney t}T>e. The individual nodules show considerable variation in size and shape, and are generally assembled in the form of nests and pockets in a residual clay derived from a dark-colored micaceous schist. The ore is associated with iron. Analyses (^f the ore from this mine gave the following result :
I II in
Per cent. Per cent. Per cent.
Manganese (metallic)... 43.58 45.87 44.18
Iron (meUllic) 5.24 5.34 6.64
Phosphorus 316 .267 .274
Silica 7.15 7.77 7.73
Ore of much better quality than is indicated in the above analyses was mined; and during the early period of mining the ore was of such superior quality that most of it was shipped to England for use in chemical purposes. Weeks gives the following annual production of ore from this mine, from 1880 to 1885, inclusive:
Year Long Tons
1880 104
1881 50
1882 130
1883 40
1884 76
1885 600
The Piedmont Manganese mins is located about 8 miles east of Lynchburg. It was formerly known as the Oxford Furnace Tract and was worked by the Lemer Mining Company, which mined from 2,000 to 3,000 tons of ore. The Piedmont Manganese Company recently ac- quired the propeirty and is actively engaged in mining the ore on a large
OXIDES. 241
scale. Mining has reached a depth of about 75 feet with no indications of the ore giving out. The ore is of excellent grade as shown in the analyses given below, and it is suitable for chemical, steel, and brick manufacturing purposes.
Analyses of the ore kindly furnished me by the President, Mr. D. W. Meyers, and made by Ricketts and Banks, are:
Per cent. Per cent.
Manganese (metallic) 54.50 50.18
Iron (metallic) 2.70
Silica 4.00 8.58
Phosphorus 25 .15
Sulphur 03
Water 6.26
The analysis in column II was made from average samples of a car of lump ore, which was poorly washed, and the sample dried at 212° F. A large mill is operated at the mines, equipped with all necessary machinery for grinding and preparing the different grades of ore for the market.
At Lynches, a station on the Southern Railway, the Bishop mine pro- duced 13 tons of manganese ore in 1885, which was shipped to England. The ore was of the same general character and quality as that mined at the Leets mine near Mount Athos, and the two mines were operated by the same party.
The Saunders mine, located about 1 mile east of Evington, a station on the Southern Eailway, may be taken as a typical example of the manga- nese mines in the crystalline area or Piedmont Virginia. This mine was first worked about 20 years ago and it has yielded to date a total pro- duction of between 6,000 and 7,000 tons of ore. The rocks strike N. 30° E. and dip 66*'-74° S. 60° E. The main rock is a thinly foilated mica schist composed largely of mica. The underlying rock on the northwest side, locally called "foot-wall," is a quartzite more or less schistose. The manganese ores occur in the residual clay derived from the decay of the mica schist. This decay is usually yellowish in color, often red, and at times is of lighter hues. The ore occurs in the form of irregular pockets, stringers, and reniform-shaped nodules. Also, it is found as stringers and thin sheets or crusts filtered in and downward along the foliation planes of the schist Only the oxides occur, pyrolusite and psilomelane. It is partly crystalline and of excellent grade.
The property has been extensively developed by shafts, tunnels and open-pitB. The greatest depth reached in mining will not exceed 150 feet, and the main tunnel, which produced large quantities of excellent ore, is
242 MINERAL RESOURCES OF VIROINIA.
900 feet in length. This tunnel was begun a few feet above local stream level and driven from the base of and directly into a prominent north- east-southwest trending ridge.
On Wiley^s Mountain, about 1% miles N. 80° E. of Evington, manga- nese ores have been worked by shafts and open-pits to a limited extent. The first work was done about 25 years ago and a shaft 106 feet deep was operated. In the valley adjacent to Wiley^s Mountain on the north- east, a small amount of manganese ore has been mined on the Phillips, Martin, and Mortimer places. Some recent prospecting has been done on Wiley^s Mountain, and the occurrence of the ore is quite similar to that described above at the Saunders mine. It is found in mica schist decay confined between two schistose quartzite bands. Strike of the schists is N. 40° E., dip N. 70° W. Other recent prospecting has been done on some of the adjacent ridges with, in some instances, encouraging results.
Nelson County.
In past years, several deposits of manganese ores have been somewhat extensively worked in Nelson county, although the ore is not mined to the writer^s knowledge at any point in the coimty at present. The ore occurs in the southeastern portion of the county, located about 2 miles north of the James river, and in the vicinity of Warminster, and Midway Mills, stations on the Chesapeake and Ohio Railway. The occurrence of the ores is in the form of pockets in the residual clays of the crystalline schists. Four mines have produced considerable ore. These are the Cabell, Bugley, Simpson, and Davis. The Cabell mine, located within two miles of War- minster, has not been worked since 1871. In 1868 and 1869, 5,000 tons of ore were mined and shipped to New Castle-on-Tyne. A reported analysis of this ore shows 82.25 per cent, of manganese peroxide. Two other analyses of ore from this mine are reported by Weeks in the Mineral Resources of the United States for 1885 as follows :
Per cent. Per cent.
Manganese (metallic) 43.30 43.02
Iron (metallic) 3.67 4.24
Phosphorus .243 .182
Silica 17.46 18.61
The Bugley mine, located about a half mile southwest of the Cabell, was worked about the same time and is said to have yielded about 2,000 tons of ore.
• Southwest of Warminster, at Midway Mills, the Simpson mine was worked in 1882, which produced about 12,000 tons of high grade ore,
OXIDES. 243
shipped to Liverpool, England. The mine was developed by a shaft 150 feet deep winch had to be abandoned on account of flooding from water. The grade of ore is reported as having improved on depth; that above the water-level yielded 70 per cent, of manganese oxide, and that below the water-level gave 80 to 85 per cent.
The Davis mine, operated in the early eighties, is said to have pro- duced 1,000 tons of ore. Weeks quotes the following analysis made of a
selected sample of this ore :
Per cent.
Manganese dioxide 90.42
Iron seequiozide 2.24
Alumina 1.13
Lime 1.22
Magnesia 2.28
Silica 1.12
Phosphoric add 43
Water 1.26
Manganese (metallic) 57.16
Iron (metallic) 1.56
Phosphorus 188
An analysis of manganese ore from Monticello gave Mr. Charles Catlett:
Per cent.
Manganese 46.99
Iron 2.60
Phosphorus 0.464
Sulphur 0.21
Silica 1.68
Pittsylvania County.
Deposits of manganese ores are known at several points along the Southern Eailway in Pittsylvania coimty, but no attempt at mining them has yet been made. About one-quarter of a mile from the Southern Rail- way and on Boanoke river, in the northern part of the coimty, a deposit of manganif erous iron ore is f oimd, samples of which gave on analysis :
Per cent. Per cent.
Manganese (metallic) 24.78 27.86
Iron (metallic) 29.86 28.14
Phosphorus 362 .347
Silica 7.02 4.32
Becent openings in this vicinity indicate a good deposit of high grade ore. Other localities where manganese ores exist are in the vicinity of Sycamore and Toshes, stations on the Southern Railway. No develop- ments have been made and the extent and quality of the ore are unknown.
244: MINERAL RESOURCES OF VIRGINIA.
THE APPALACHIAH XOTTNTAINS REOIOK.
Introdnction.
Under this division is included all those counties lying west of the Blue Ridge and embracing the Valley proper, and the area west of the Valley known as Appalachia. The principal sources of manganese ores produced in Virginia, and indeed in the United States, have been from the mines of the Valley region of Virginia, also known as the Shenandoah Valley. The principal manganiferous ore belt of this region lies along the western base of the Blue Ridge and on the eastern side of the Valley. This belt has a length of 300 miles in Virginia, and workable deposits of manganese have been found in each of the 12 counties bordering on the western base of the Blue Ridge.
Along this belt are foimd the large bodies of iron ore which are asso- ciated with the so-called Potsdam, or formation No. I of Rogers, and the ores of manganese are associated with those of iron. The manganese ores are usually found embedded in residual clays derived by decay from Cambrian ferriferous shales, which overlie the Potsdam quartzite. In other places over the Valley region, manganese ores occur similarly em- bedded in residual clays derived from limestone. Manganese and mangani- ferous iron ores are also found in this region associated with other rocks than those of the Potsdam and the Cambro-Ordovician limestones; espe- cially have they been noted in the basal member of the Devonian, the Oriskany.
Located in the Valley region of Virginia is the famous Crimora mine of Augusta county, which has produced more ore than all other mines in the United States combined. The principal operations in the Valley province are described below by counties.
DESCRIFTIOK OF INDIVIDTJAL ABEAS.
Page County.
On the lands of the Shenandoah Iron Company near Milnes, a station on the Shenandoah Valley railroad, a large quantity of manganiferous ores were mined as early as 1884. In 1884, 208 tons of manganiferous ore were shipped from these mines, and in 1885 the production amounted to 2,155 tons. Weeks gives the average of analyses of these ores to be:
Per cent.
Manganese (metallic) 28.00
Iron (metallic) 17.00
Phosphorus 0.15
OXIDES. 246
The ore is associated with brown hematite in a wash deposit that is irregular and uncertain. Specimens of ore, collected by Mr. McCreath from a deposit on the Garrison tract, the top of which is described as a fine ore, but becoming coarser and harder on depth, gave the following results on analysis
Fine Ore. Lump Ore.
Per cent. Per cent.
Manganese (metallic) 52.691 53.656
Iron (metallic) 2.325 1.537
Phosphorus 0.324 0.237
Silica 2.795 1.965
Three miles east of Milnes station, a manganiferous iron ore has been \7orked at the Kimball mine. This is developed by 2 openings known as the Atwood and the Bolan, the largest proportion of manganese being found in the Atwood opening. According to Weeks, a mixed sample of the ores from 2 openings, in the proportion of two-thirds from the Atwood and one-third from the Bolan, gave on analysis:
Per cent.
Iron (metallic) 40.857
Manganese (metallic) 7.349
Phosphorus 0.084
Siliceous matter 15.440
Weeks quotes a second analysis of the ore made by Bowron as follows:
Per cent.
Iron sesquioxide 70.00
Manganese oxide 13.31
Phosphorus trace
Silica 4.73
Alumina 0.86
Water 11.03
Mr. E. A. Schneider reports the following analysis made of manga- nese ore from the Round Head tract, near Marksville:
Per cent.
Manganese 51.46
Iron 2.94
Phosphorus 0.23
Silica 4.17
Water 4.97
Two miles southwest of Marksville good surface indications of man- ganese occur over a considerable area. A sample of the ore was analyzed by Booth, Garrett and Blair with the following results :
Per cent.
Manganese (metallic) 49.613
Iron (metallic) 1.050
l^hoephorufl 0.310
246 MINERAL RESOURCES OF VIROINIA.
Auguita County.
This is the most important manganese producing county in the country, because largely of the famous Crimora mines, which have produced more ore than all other mines in the United States combined. lTiima:oiiB other mines have been operated in Augusta county, which have been opened up near and along the Shenandoah division of the Norfolk and Western Railway, near Lyndhurst, Stuarfs Draft, Vesuvius, and Waynes- boro.
The most important mine in this county and indeed in the United States, is the Crimora, located 2.5 miles southwest of CrimKMra, a station on the Shenandoah railroad, with which it is connected by a brandi road. A stock company bought the land containing this mine in 1867 aod mining was continued until 1869, when it was alternately idle and work^ until 1882. In 1882, the mines were leased and systematic productdon of ore on a large scale was begun. The ore is localized in an'elliptical-ehaped basin about 500 feet wide and 800 to 900 feet long of Potsdam quartzite, which is a very hard and dense, light-colored rock.
Figure 40 shows the ground plan of the immediate vicinity of the mine. Figure 41 represents cross-sections along the lines marked in figure 40. On the east side the quartzite dips to the westward along the line AA in figure 40. CC marks the position of an anticline the beds of which dip both toward the west and the east, forming a syndine to the east, the axis of which is indicated by the line BB.
The basin is filled with a clay derived by decay from an overlying Cambrian shale. The clay has been preserved from erosion throu^ sharp synclinal folds. The ore, which is largely psilomelane, is irregularly assembled in the clay in the shape of nodular lumps and masses from the size of a small pebble to those weighing a quarter of a ton or more. In places, the ore seems to be distributed through certain layers of the day more than through others, but, wherever found, its distribution is irregular and it does not conform to the bedding. The mine is shown in plate XXXVII, figure 2.
The clay filling the basin, through which the ore is distributed, is covered with a variable depth of drift, derived by wash from the adjacent mountain slope. This drift is composed of admixed clay and large and small quartzite fragments, and has a probable depth of 15 feet, which requires to be stripped from the ore-bearing clays imdemeath, before working. In color, the ore-bearing clay is yellow, buff, and of lighter
MINERAL RESOURCES OF VIUHINIA,
I'LATE XXXVII.
Fig. 2. — Crimora iiianHnnfue iiiinpfi, Augusta county. Virginia. fRlMORA MANfiAXESE ft[ILLIN"G PLANT AXU MINES.
* '
^
I I-
Fig. 41. — 8«ctioQB throQfth Grimon mtngsnese deposits. (After C £ Hall)
248 MINERAL RESOURCES OF VIRGINIA.
shades. The ore is further assembled in this clay in the form of nests, pockets, and stringers, which may or may not be connected.
The ore is principally psilomelane, with some pyrolusite, and wad. Quite a good proportion of it is crystalline in texture. A commodious mill for preparing the ore for shipping is operated at the mine and is shown in plate XXXVII, figure 1. At present, about 16 per cent, of the ore requires jigging and practically all of it is washed to free it from adhering clay. The ore, mined to date, will probably average 48 per cent, of metallic manganese, 1.5 to 2 per cent, metallic iron, phosphorus 0.05 per cent., and silica 7 to 8 per cent. The ore is characterized by uniformlj low phosphorus, the highest not exceeding .112 per cent. In the jigged ore, silica will give a higher average than quoted above, sometimes exceed- ing the limit, 10 per cent.
McCreath gives the following complete chemical analysis of lump man- ganese ore, comprising 228 pieces from which the sample was prepared,
from the Crimora mine:
Per cent.
Binoxide of manganese 81.703
Protoxide of manganese 7.281
Sesquioxide of iron .533
Cobalt oxide .364
Nickel oxide 096
Zinc oxide 623
Alumina .896
Baryta 829
Lime 880
Magnesia .630
Phosphoric acid .171
Alkalies 467
Water 3.405
Silica 2.132
Manganese (metallic) 57.291 *
Iron (metallic) .373
Phosphorus .075
Weeks reports the following analyses of manganese ore from the
Crimora mines:
Per cent. Per cent. Per cent. Per cent.
Manganese (metallic) 48.530 50.541 48.162 44.641
Iron (metallic) 1.985 1.957 4.568 3.263
Phosphorus 0.103 0.095 0.087
SiUca 10.20 10.12 10.30 14.00
According to McCreath an analysis of the best grade of ore from the Crimora mine gave as above :
Per cent.
Manganese (metallic) 67.291
Iron (metallic) 373
Phosphorus 076
OXIDES. 249
Fifty-six acres of ground have been tested by 700 drill-holes put down to a depth of 160 feet. The underlying quartzite is reached by drilling at a depth of 212 feet. The greatest depth reached in working the ore is 198 feet. The total area of worked ground is about 12 acres. Of this acreage, the American Manganese Company worked about 8^^ acres; the additional 3 acres have been worked by the Crimora Manga- nese Company of New Jersey, which is operating at present. The worked area has been stripped to a considerable depth and is further developed by numerous pits, entries, and shafts.
Adjoining the Crimora mine on the south, is the mine of the Old Dominion Manganese Company, A number of openings were worked many years ago close to the line of the Crimora mine, but these are now entirely filled in and hardly any indication of them remains. A shaft has recently been sunk in a reef of hard quartzite near the old openings and near the line, from which both the Crimora Manganese Company and the Old Dominion Manganese Company are working. The former company is operating a drift from this shaft at the 186-foot level which passed through 2,800 feet of the quartzite before penetrating the clays. The Old Domin- ion Manganese Company is operating a drift from the same shaft at the 176-foot level.
In 1859, Siberi; opened a mine on Bear creek, 2 miles southeast of Lyndhurst station, and close up to the western base of the Blue Ridge. A shaft was sunk which struck the ore at a depth of 45 feet. A drift 20 feet long was run from the bottom of the shaft and it is reported that 250 tons of ore were mined from the drift and shaft and shipped to London. Analyses of the ore taken from this mine made by J. Blodgett liritton, gave:
Per cent. Per cent.
Manganese peroxide 93.06 80.77
Iron peroxide trace 2.98
Silica 18 3.98
Alumina 91 2.81
Baryta 2.81 .31
Water 2.75 2.93
A new shaft was sunk in 1885 and 1886.
Manganese ores were mined by Sibert before the War on the Kennedy tract at the foot of the Western Blue Ridge, 3 miles from Stuari;'s Draft, a station on the Shenandoah Valley railroad. It is reported that 100 tons of ore were mined here in 1859. Both manganese and manganiferous
250 MINERAL BE80UB0E8 OF VIBOIKIA.
iron ores are reported on this property. An analysis of the manganese ores made by Professor F. P. Dunnington from the Kennedy tract gave:
Per cent.
Aianganese (metallic) 43.30
Iron (metallic) 3.88
Sulphur 083
Phosphorus 52
Barium 6.93
Silica, water, etc 17.69
Manganese and manganiferous iron ores have been mined from a number of places in the vicinity of the old Cotopaxi and Vesuvius furnaces, near the line between Augusta and Rockbridge counties, and close to the Shenandoah Valley railroad. The principal mines are, the Blue, Faubefy Newton, Kelly, and several others, on Big Mary creek. It is reported that Sibert mined 75 tons of nodular masses and lumps of psilomelane at the Fauber mine. Weeks reports an analysis made by McCreath of a sample of ore comprising 143 pieces, taken from along the face of the
open-cut at the Newton mine, as follows:
Per cent.
Iron (metallic) 41.125
Manganese (metallic) 8.221
Phosphorus 265
Siliceous matter 14.830
Tlie Kelly mine is in Eockbridge coimty and is a part of the old Vesuvius furnace property. Both iron and manganiferous ores are found, the latter occurring nearer the Potsdam than the former.
Tn the summer of 1906, the Raymond Mining Company was operating a property 4 miles east of Stuart^s Draft on the Shenandoah Valley railroad. Manganese mining near Lyndhurst station was also in progress in 1906 by Kendall and Flick.
The above mines at Vesuvius and Lyndhurst have recently been ac- quired by the Manganese Corporation of Virginia and preparations are being rapidly made for the extensive mining and shipping of ore. The ore is reported to be of excellent quality, that from the Vesuvius mines showing from 45 to 47.72 per cent, manganese, and as low as 0.065 per cent, of phosphorus.
Rocking^ham County.
In 1894, the Kendall and Flick mine, near Elkton, in Rockingham county, is reported to have produced the largest amount of ore in the State. The production is given at 1,190 tons and the ore averaged from 48 to 49 per cent, of metallic manganese. It contained a small excess of silica
OXIDES. 251
but was within the limits in phosphorus. This mine continued operations in 1896 but is not now producing. An analysis of the ore gave :
Per cent.
Manganese (metallic) 48.25
Ir<m (metallic) 2.70
Silica 10.60
Water 4.00
Professor F. W. Clarke reports the following analysis of manganese ore from the Church Mountain mine. A noteworthy feature is the high
cobalt :
Per cent.
Insoluble matter 22.11
Iron and aluminum oxides 5.14
Manganese 39.20
Cobalt 2.48
IgnHion 11.30
Manganese ores, analyzed by Mr. Charles Catlett, from near Elkton,
Rockingham county, gave:
Per cent. Per cent. Per cent.
Manganese 43.94 49.66 48.75
Iron 3.43 8.53 2.79
Phosphorus 0.166 0.076 0.085
Sulphur 0.07 0.089 trace
Silica 15.88 1.80 15.08
Botetourt County.
The most extensively worked manganese mine in Botetourt county is the Houston, located about 1 mile from Houston, a station on the Shenan- doah Valley railroad. The manganese deposits at this mine are situated well up on the west slope of the Blue Ridge at an elevation of about 400 feet above the drainage level of the surrounding country. Manganese ores are here found over a distance of nearly 1 mile extending in a N. 35° E. direction. Many openings have been made from which large quantities of ore have been taken. The rock associations here are apparently the same as those described above at the Crimora mine in Augusta county. The rock imdemeath the clays is the Potsdam quartzite.
The ore comprises manganiferous iron and manganese in close associa- tion. In the eighties, the Houston mine was the principal producer of man- ganiferous iron ores in Virginia. The manganese ores occur in a tough yellow clay assembled as nests and pockets, which yielded in some cases 100 to 150 tons of high grade ore in lumps the size of an egg and smaller, and sufficiently clean to require no washing. The pockets of manganese ore are sometimes found next to the iron ore. According to Weeks a
252 MINERAL RE80UBCES OF VIBGINIA.
selection of 116 pieces representing the iron ore, and 68 pieces represent- ing the manganese ore, gave McCreath on analysis:
Iron Ore. Manganese Ore.
Per cent. Per cent.
Manganese (metallic) 7.277 44.312
Iron (metallic) 47.150 12.325
Phosphorus 061 .101
Siliceous matter 8.030 5.470
A selected sample of the manganese ore from the same mine gave:
Per cent.
Manganese (metallic) 59.870
Iron (metallic) 600'
Phosphorus .049
Silica 2.300
The production of ore from this mine for the years 1883 to 1885, inclusive, was 4,810 long tons proportioned as follows:
Long ton**.
1883 2,900
1884 828
1885 1,082
An analysis of manganese ore on the Champman property south of the
Houston mines gave :
Per cent.
Manganese (metallic) 45.80
Iron (metallic) 3.06
Phosphorus 164
Frederick County.
The Paddy Mills manganese mine in the southwest comer of Frederick county has produced about 2,000 tons of manganese ore, mined mostly before the War. The mine occupies a conical -shaped hill about a square mile in area and rises to an elevation of about 150 feet above the drainage level of the surrounding country. The ore is pyrolusite associated with limestone. It averages about 50 per cent, metallic manganese, 4 per cent, metallic iron, and from .09 to .10 per cent, phosphorus. The greatest depth reached in mining is 50 feet.
Shenandoah County.
Manganese ores were somewhat extensively worked and shipped before the War at Van Buren furnace, in Shenandoah county. The ore is reported as having occurred in pockets that were more or less continuous and could 1 e traced on the surface for a distance of more than 3 miles. The principal
OXIDES. 253
mine was located at the western end of Cupola Mountain, although good indications are reported in the broken hills to the southwest of this mountain. The washed ore is reported to have analyzed upwards of 70 per cent, manganese oxide.
At Powell's Fort on the northeast Massanutten Mountain, in Shenan- doah county, manganese ores were mined at different times for many years. More than 1,000 tons of ore were shipped from this property prior to 1886. It was developed by 3 or more shafts of considerable depths. The ore is described as being remarkably clean; almost entirely free from foreign matter, and is a good grade of soft crystallized pyrolusite. According to Weeks, analyses of the ore jdelded J. B. Britton 94.30 per cent, of manga- nese oxide in one sample, and G0.6G per cent, metallic manganese in another sample. A sample of ore taken from the mine of the Manganese and Iron Company's property was analyzed at the laboratory of the Albany and Rensselaer Iron and Steel Company, Troy, New York, with the follow- ing results:
Per cent.
Manganese 50.302
Iron 0.844
Phosphorus 0.190
Silica 1.500
An analysis made of a specimen of manganese ore from Powell's Fort, east end of Massanutten Mountain, Warren county, gave Mr. Charles Catlett :
Per cent.
Manganese 48.59
Iron 3.07
Phosphorus 0.349
Sulphur 0.12
Silica 9.20
Rockbrldg^e County.
On Guy Run, about 6 miles south of Goshen, a station on the Chesapeake and Ohio Railway, an extensive deposit of manganese associated with iron has been worked at several different times. The manganese ores are embedded in clays in the form of pockets and are found in close proximity to the brown iron ores of the Oriskany horizon. An analysis of the man- ganese ore from this locality gave:
Per cent.
Manganese (metallic) 64.59
Iron (metallic) 3.01
Phosphorus .55
254 MINERAL RESOURCES OF VIROIKIA.
An analysis of manganese ore by Chatard from Harts Bottom gave :
Per cent.
Aianganese 41.69
Iron 2.18
Phosphorus 0.22
Sulphur 0.12
Other Valley Deposits.
Along the Cripple Creek extension of the Norfolk and Western Bailway, numerous openings are made in Pulaski, Wythe, and Smjrth counties, from which manganese and manganiferous iron ores have been mined.
Four miles east of Radford furnace, in Pulaski county, on Mack's Moimtain, manganese ore associated with brown iron ore, occurs. An analysis made of a sample of 132 pieces of the ore by McCreath gave:
Per cent.
Iron (metallic) 39.976
Manganese (metallic) 14.785
Phosphorus 1.074
Siliceous matter 5.840
Four miles southwest of Max Meadows, in Wythe county, and at the Noble furnace in the same county, manganiferous iron ores have been mined, which showed on analysis 49 to 51 per cent, metallic iron, and 3 to 5 per cent, metallic manganese.
At the Razor bank on the South Fork of the Holston river, in Ryj
Valley; on Chestnut Eidge, 6 miles from Seven Mile Ford Station; and
near Marion, Smyth county, manganiferous iron ores have been opened.
An analysis of a sample comprising 133 pieces of the ore from the Razor
hanJc gave McCreath :
Per cent.
Manganese (metallic) 10.181
Iron (metallic) 40.100
Phosphorus .536
Siliceous matter 10.520
Likewise a sample of the ore from near Marion, Smyth county, gave
on analysis:
Per cent.
Manganese (metallic) 9.91
Iron (metallic) 45.32
Phosphorus 086
Silica 1.76
Many outcrops and other indications of manganese ore are found in Qnag, Oiles, Bland, and Tazewell counties. Some of the ore has been
OXIDES. 255
mined to a limited extent in different places, but as yet no extensive develop- ments have been made. These ores are usually associated with those of iron and are reported largely from the Oriskany horizon.
Seven manganese deposits have been opened on Gap Moimtain^ in Craig county, and the analyses given below of the ore from these open- ings show its character:
I II III IV V
Per cent. Per cent. Per cent. Per cent. Per cent.
Manganeee (metellic) 45.00 52.42 49.48 53.06 50.50
Iron (metalUc) 6.83 1.82 4.81
Phoephorus 085 .303 .063 .058 .026
Silica 4.70 .46 2.63 1.67 .58
I and II. Analyses by T. T. Morrell, Cambria Iron Company. III. Analysu by 8. P. Sharpless. IV and V. Analyses by Vulcan Steel Works, Saint Louis, Missouri.
Analyses of manganese ore from Lick Mountain, near Wytheville^ Wythe county, gave Mr. Charles Catlett the following results :
Per cent. Per cent. Per cent. Per cent.
Mi&nganese 41.89 57.67 51.05 44.60
Iron 2.57 1.98 2.92 3.96
Pbosphonis 0.036 0.009 0.161 0.46
Sulphur 0.09 0.067 tract tract
Insoluble matter 4.05 1.85 4.32 15.81
Analyses of manganese ore from Cripple creek, 8 miles from Wythe- ville, W3rthe county, gave Mr. Catlett:
Per cent. Per cent.
Manganese 24.86 32.65
Iron 2.72 3.61
Phoephorus 0.05 0.097
Sulphur trace 0.030
Silica 47.30 27.86
METHODS OF MUHNG.
The nature of the manganese ores mined in Virginia is one of irreg- ular distribution, in the form of nodules and pockets, through residual clays, which range in thickness from a few feet up to several hundred feet. The ore distribution varies considerably, and the deposits are limited both vertically and laterally; hence the methods for operating in one place will necessarily vary somewhat in detail from those in another. The method of mining will depend largely upon the location of the deposits and their depth helow the surface. Open-pit and cut, shaft and tunnel, work are employed. These are often used together to advantage in the same place, especially where the ore begins at or near the surface and continues irregularly to some depth below. In such cases, open-pit and
256 MINERAL BES0UBCE8 OF VIRGINIA.
cut work is used, and from the bottom of the open work shafts are sunk and drifts are run at different levels from the shafts. Tunnelling be- comes necessary in most of the steeper slope deposits. In the lower or flat-lying deposits, shafting is most advantageously employed. In most cases of tunneling and shafting in the larger operations, timbering is necessary on account of the liability of caving of the clays.
PREPARATION OF THE ORE.
The occurrence of the ores in the clay mean, usually, more or less admixture of the ore with clay. Usually, the only treatment of the ore necessary before shipping is to free it from adhering clay. Crushing and jigging are necessary in the spongy or porous type of ore, the numerous cavities of which are filled with the clays; also in those ores containing considerable free quartz grains and cemented fragments of the rock. Washing will usually suffice for cleansing the bulk of the ore. In the crushed and jigged ore, subsequent washing is also necessary.
For washing the ore the ordinary log-washer is used similar to that used for cleansing brown iron ores. Briefly, the log- washer consists of a long and stoutly built box, of sufficient length and depth to contain the log. The box or trough is elevated at one end. A log or central shaft 25 to 40 feet long, carrying heavy iron flanges, spirally arranged the length of the log, revolves lengthwise in the box or trough. The ore is led at the lower end of the box and is gradually forced by the revolving lo^^ to the u])per end, where it passes out. A constant stream of water plays on the ore in the box. The constant agitation and beating of the ore by the log and the washing by water frees it from adhering clay. Steam is the motive power.
Uses.
Penrose divides the various uses made of manganese and its compounds into three classes: (1) Alloys; (2) oxidizers; and (3) color- ing materials. Each class includes the application of manganese in various manufactured products or as a reagent in the different metallurgical and chemical processes. The more important of these are given below:
f Spiegeleisen ) ^jj ^^ manganese and iron. I Ferromanganese j -^ »
. ,j ^ J Manganese bronze — Alloys of manganese and copper with or without iron, oys. ^ ^ j^ alloy of manganese, aluminum, zinc, and copper with
Oliver bronze | ^ ^^^.^j^^ quantity of silica. Alloys of manganese with aluminum, zinc, tin, lead, magnesium, etc.
Ozidijgers
OXIDES. 267
' Manufacture of chlorine. Manufacture of bromine.
As a decolorizer of glaas (also for coloring glass, see below). As a drier in yamishes and paints. LeClanche's Battery. Preparation of oxygen on a small scale. Manufacture of disinfectants (manganates and permanganates)
r Calico printing and dyeing.
Coloring J Coloring glass, pottery, and brick.
Materials \ p„. ^^ i Green.
I ^*'"^ \ Violet.
In addition to these^ a certain amount of manganese is used as fiui. in the smelting of silver ores, and its various salts are employed in chemical mannfacture and for medicinal purposes. In the manufacture of glass, the manganese is used to remove the green color caused by the presence of iron and to impart various colors to the glass, particularly the violets, browns, and blacks. Manganese finds its principal use in the manu- facture of iron and steel, chiefly in the production of steel and of a pig-iron rich in manganese for use in cast-iron car-wheels.
According to Weeks in the 16th Annual Report, United States Geologi- cal Survey, Part III, page 394: "It has been found in recent years that a chilled cast-iron car-wheel containing a percentage of manganese is much tougher, stronger, and wears better than when manganese is absent. For this reason large amounts of manganiferous iron-ores are used in the manufacture of Lake Superior charcoal, pig-iron intended for casting into chilled cast-iron car-wheels.^^
Production.
Virginia is the largest producer of manganese ores in the United States, and, with but 6 exceptions, has ranked first among the manganese-producing states in the United States for the past 26 years. The table below gives the production of manganese ores in Virginia from 1880 to 1906. The chief production of manganese in Virginia has been in the Shenandoah Valley. In this Valley, southwest of Roanoke, there are veiy promising indications of ore, but no great amount of ore has yet been raised. In addition to the ore produced in the Valley and in the Piedmont r^on, manganiferous iron ore has been produced in places in the Blue Ridge mountains proper.
258
MINXBAL REBOURGBB OF YIBOINIA.
Annual production of manganese and manganiferous iron ores in Virginiii
from 1S80 to 1906.
|
Year |
Manganeoe |
. Manganifgfow iron |
Value |
Year 1893 |
M.ng.ne.e |
Manganifer- ous iron |
Vtloe |
|
Long ton8 |
Long tons |
Long tons |
Long tons |
1 |
|||
|
4,092 |
1,188 |
30,802 |
|||||
|
1880 |
3,*irtl |
1894 |
1,797 |
||||
|
1881 |
3,295 |
1895 |
1,715 |
||||
|
1882 |
2,982 |
1896 |
2,018 |
21,485 |
|||
|
1883 |
"),355 |
1897 |
3,650 |
33,690 |
|||
|
1884 |
8.980 |
1898 |
5,662 |
55,938 |
|||
|
1885 |
18,745 |
3,237 |
168.942 |
1899 |
6,228 |
53.069 |
|
|
1886 |
20,567 |
497 |
232.594 |
1900 |
7,881 |
69,924 |
|
|
1887 |
19,835 |
1,025 |
253.833 |
1901 |
4,275 |
52,853 |
|
|
1888 |
17,646 |
1902 |
3,041 |
3,000 |
29,444 |
||
|
1889 |
14,616 |
156,257 |
1903 |
1,801 |
2,802 |
19,611 |
|
|
1890 |
12,699 |
125,121 |
1904 |
3,054 |
28.406 |
||
|
1891 |
16,248 |
180,633 |
1905 |
3,947 |
35^209 |
||
|
1892 |
6,079 |
2.842 |
58.966 |
i |
Ferceniaye of the total annual production of manganese ores in the
United Staies, produced by Virginia,*
Year
1880.
1881.
1882.
1883.
1884.
1885.
1886.
1887.
1888.
1 889 .
1890.
1891.
1892.
Per cent. 63.5 67.3 65.8 87.0 88.2 80.6 68.1 57.4 60.4 60.3 49.4 69.3 44.7
1893.
1894
1895.
1896.
1897.
1898.
1899.
1900.
1901.
1902.
1903.
1904.
1906.
Per cent. 63.0 28.4 17.9 20.0 32.8 35.4 62.6 66.9 35.6 40.6 60.3 97.0 95.8
111 hs8y and 1890, the Crimora and Houston mines produced nearly all the ore. During the same years the Leets mine near Mount Athos pro- duced some high grade pyrolusite which was used in the manufacture of glaa.s and bromine.
References.
OiiiiiiiiigLon, F. P. On The Formation of Deposits of Oxides of Manga*
nese. American Journal of Science, 1888, XXX VI. 176-178.
*'J UiiiMi (uileulations are based on the total production in Virginia and the total f;i«/<lii< f iou in the United States by vears as given in the Minenl Reeources of thf
I ^ • r »
'.•.:•. Ji. ^
MINDUAI. KKSUflUKS OF VlllfilXl.l
[■I. ATE XSXVIIL
OXIDES.
1^59
W. M.
■-^- • .
ff
IbBill, O. P.
American Manufacturer. The Grimora Manganese Mine of Virginia.
Engineering and Mining Journal, 1890, XIAX, 333-334.
Hally C. E. Geological Notes on the Manganese Ore Deposits of
Crimora, Virginia. Transactions American Institute of Mining Engineers, 1892, XX, 46-49: Engineer- ing and Mining Journal, 1891, LII, 94.
Crimora Manganese Deposits. The Virginias, 1883, IV, 44^6.
Notes on the Mineral Deposits at Certain Localities in the Western Part of the Blue Ridge. The Virgi- nias, 1883, IV, 21-22, 42-47, 56-69, 73-76, 92-93; 1884, V, 43.
The Non-Metallic Minerals. New York, 1904, 119- 128.
PenroBe, B. A. F. Manganese: Its Uses, Ores and Deposits. Annual
Report of the Arkansas Survey, 1890, I.
Weeks, J. D. Manganese. Mineral Resources of the United States,
1886, 303-356.
Manganese. Report on Mineral Industries in the United States at the Eleventh Census for 1890, 287-329.
Manganese. 16th Annual Report, U. S. Geological Survey, 1896, Part III, 329-467.
Manganese. Mineral Resources of the United States, 1892, 169-226.
Each Tolume of the Mineral Resources of the United States from 1882 to date, oontaina some information on the Virginia manganese deposits. See also the yolumes of the Mineral Industry.
7. UNERAL AND ABTESIAN WATEBS.
XiiMral Waten. — ^The mineral waters of Virginia are an important souroe of reronue. Virginia has a very large number of spring resorts and a greftt Taiiety and abundance of well known commercial waters. Indeed, Yixginia is par excellence a mineral spring state, occupying among the Sonih Atlantic States the same position New York does in the North Atlantic sectioiL Virginia is second only to New York in the number of apringB that are utilized commercially, and exceeds New York in the number of resorts. The Hot Springs of Virginia, in Bath county, are among the most celebrated in the country. (See plate XXXVIII.)
260 MINERAL RESOURCES OF VIROINIA.
Most of the best known springs in the State are located in the Monntain region, which includes the Blue Bidge and the Alleghanies. Many excel- lent springs occur in the Piedmont region, east of the Blue Bidge, and the waters from some of these are among the most celebrated in the country.
All classes of mineral waters are found in the State. They are naturally divided into (1) those containing mineral salts in such proportion as to give them medicinal value, and (2) those approximately pure waters which are sold extensively for table or domestic use. The thermal springs are entirely confined to the Mountain region.
Out of the total of 59 mineral springs credited to Virginia, 43 reported sales during the years 1904 and 1905. These were:
^tna lithia Springs, Boanoke, Boanoke County. Alleghany Spring, Alleghany Springs, Montgomery County. Augusta White Lithia Spring, near Augusta Springs, Augusta
County. Basic Lithia Spring, Basic City, Augusta County. Bath Alum Springs, Bath County. Bear Lithia Spring, near Elkton, Bockingham County. Beaufont Lithia Spring, Beaufont, Chesterfield County. Bellfont Lithia Spring, Manchester, Chesterfield County. Berry Hill Mineral Spring, near Elkwood, Culpeper County. Blue Eidge Spring, Blue Bidge Springs, Botetourt County. Buffalo Lithia Springs, Buffalo Lithia Springs, Mecklenburg Comity- Como Lithia Springs, East Bichmond, Henrico County. Crockett Arsenic Lithia Spring, Crockett Springs, Montgomeiy
County. Diamond Spring, 5 miles east of Norfolk, Norfolk County. Farmville Lithia Spring No. 2, Cumberland County, near Farm—
ville, Prince Edward County. Fonticello Lithia Spring, near Bichmond, Chesterfield County. Golinda Lithia Spring, Augusta County. Harris Anti-Dyspeptic and Tonic Springs, Burkeville, Nottoway
County. Healing Springs, Healing Springs, Bath County. Hume Spring, Bancroft, Alexandria County. Hunter Pulaski Alum Spring, Walkers Valley, Pulaski County. Jeffress Lithia Silica Spring, Jeffress, Mecklenburg County. Kayser Lithia Spring, Staunton, Augusta County. Lone Jack Spring, Lone Jack Station, Campbell County. Magee Chlorinated Lithia Spring, Clarksville, Mecklenburg County- Massanetta Springs, Harrisonburg, Rockingham County. Mecklenburg or Chase City Mineral Springs, Chase City, Meckleii'
burg County.
OXIDES. 261
Montvale Hygeia Springs, Montvale, Bedford County.
Nye Lithia Springs, WytheviUe, Wythe County.
O'Connell Lithia Spring, near Stribling Springs, Augusta County.
Otterbum Lithia and Magnesia Springs, Amelia, Amelia County.
Paeonian Spring, Pseonian Springs, Loudoun County.
Bockbridge Alum Springs, Rockbridge Alum Springs, Rockbridge
County. Rockingham (Virginia) Springs, near McGaheysville, Rockingham
County. Seawright Magnesia Lithia Spring, Staunton, Augusta County. Seven Springs, near Glade Spring, Washington County. Shenandoah Alum Springs, near North Mountain, Shenandoah
County. Stribling Springs, near Staunton, Augusta County. Sublett's Lithia Springs, near Danville, Pittsylvania County. Virginia Lithia Springs, Osceola, Chesterfield County. Virginia Magnesian Alkaline Spring, near Staunton, Augusta
County. Wallawhatoola Alum Springs, near Millboro Spring, Bath County. Wyrick Spring, Crockett, Wythe County.
Chemical Analyses.
It is only possible to give analyses of water from a few of the repre- sentative mineral springs in the State. The analyses of the springs repre- sented have been selected with the view largely of indicating the variety of mineral waters in the State, which are of commercial value. Waters from some of the most important springs in Virginia are not included in the list for the reason that representative analyses were not available.
The following is an analysis of the Alleghany Springs water near Shawsville, Montgomery county, made by Dr. P. A. Gtenth:
One United States gallon of 231 cubic inches contains:
Calcium carbonate 3.61 grains
Maffnesium carbonate 0.36 **
Litnium carbonate trace
Strontium carbonate 0.06 "
Barium carbonate 0.02 "
Magnesium carbonate 0.06 "
Iron carbonate 0.16 "
Cobalt carbonate trace
Zinc carbonate trace
Copper carbonate trace
Lead carbonate trace
Sodium sulphate 1.72 "
Calcium sulphate 116.29 "
Magnesium sulphate 50.88 **
262 MIKERAL RESOUBCES OF YIBOINIA.
Potaftsimn BulpbAte 3.70 grains
Magnedum nitimte ZJiZ **
Aluminium nitrmte 0.56 "
Aluminium phosphate 0.03 **
Aluminium silicate 0.21 "
Sodium chloride 0.28 -
Calcium fluoride 0.02 "
Antimcmium oxide trace
Silica 0.88
Crenic acid trace
Aprocrenic acid trace
Organic matter 2.00
ft
«
183.06 grains Gases:
Carbonic acid 0.56 cubic inches
Sulphuretted hydrogen trace
The following is an analysis of the Beaufont Lithia Spring water
located in Chesterfield county, near Eichmond, made by Froehling vai Bobertson :
One United States gallon of 231 cubic inches contains:
Magnesium bi-carbonate 38956 grains
Calcium bi-carbonate 35282 "
Sodium bi-carbonate .34923 **
Iron ( ferrous) bi-oarbonate 04741 **
Manganous bi-carbonate trace
Potassium sulphate 13646 "
Potassium chloride 12947 **
Sodium chloride 35749 "
Sodium iodide 00412 "
Sodium bromide trace
Sodium arsenate trace
Sodium phosphate 00332 "
Lithium chloride 02799 "
Alumina 02099 "
Silicic acid 96691 "
2.78577 grains Carbon dioxide free (gas) 8.5 cubic inches
An analysis made by Froehling and Roberi^on of the Blue Edge Springs water, Botetourt county, gave:
One United States gallon of 231 cubic inches contains:
Magnesium sulphate 47.01306 grains
Calcium sulphate 100.13201 "
Sodium sulphate .36740
Potassium sulphate .65724
Magnesium carbonate 1.21885 "
Calcium carbonate 3.96562 "
Strontium carbonate .29509 "
Barium carbonate .02566 "
(C
«
OXIDES. 268
Manganese carbonate .01749 grains
Nickel and cobalt carbonate trace
Iron (ferrous) carbonate .10847 "
Lead carbonate trace
Copper carbonate trace
Sodium diloride 1.25967 "
lathium chloride 03732 "
Sodium arsenate 00210 "
Sodium iodide 00026 "
Sodium bromide trace
Calcium fluoride .00146 "
Magnesium nitrate .35574 "
Ammonium nitrate .02814 "
Aluminium phosphate .01576 "
Aluminium silicate 15279 "
Silicic acid 1.36298 "
167.00710 grains Carbon dioxide combined 2.57648 "
159.58358 grains Gases:
Carbon dioxide 38.2 cubic inches
Hydrogen sulphide 3.00 " *
The following analysis of spring No. 2, by Professor Wm. P. Joury of the Buffalo Idthia Springs water^ Mecklenburg county, shows its composi- tion to be:
One United States gallon of 231 cubic inches contains:
Magnesium sulphate 0.88 grains
Aluminium sulphate 9.07 **
Calcium sulphate 33.06 "
Potassium carbonate 29.30 "
Calcium bi-carbonate 14.96 "
Lithium bi-carbonate 2.26 "
Iron bi-carbonate 0.30 "
Buyta bi-carbonate 1.75 "
Sodium chloride 4.92 "
Silica chloride 1.87 "
Phosphoric acid trace
Iodine trace
Organic matter small amount
98.36 grains Oases:
Sulphuretted hydrogen . . 8.30 cubic inches
Carbonic acid 60.20 *'
An analysis of the water from the Crockett's Arsenic Lithia Springs^ Shawsville, Montgomery county, by Froehling and Robertson gave:
One United States gallon of 231 cubic inches contains:
Manganese carbonate 1.18 grains
Calcium carbonate 5.90 "
264 MINERAL BESOUBCBS OF VIBOINIA.
Strontium carbonate 0.09 grains
Barium carbonate trace
Lithium carbonate 0.07 "
Copper carbonate trace
Lead carbonate trace
Zinc carbonate trace
Manganese carbonate trace
Magneeium sulphate 3.04
Calcium sulphate 2.26
Potassium sulphate 1.26 "
Iron sulphate 0.04 "
Sodium sulphate 1.86 "
Sodium chloride 1.23 "
Sodium bromide 0.01 "
Sodium iodide trace
Sodium arsenate 0.02 **
Aluminium phosphate trace
Aluminium silicate 0.12 "
Ammonium nitrate trace
Silicic acid 1.29 "
18.35 grains Carbonic anhydride combined with monocar-
bonates to form bi-carbonates 2.23 '*
««
it
21.68 grains
The analysis of the water from the Fonticello Lithia Springs, in Chesterfield county, near Richmond, by Dr. Henry Froehling, shows the following composition:
One United States gallon of 231 cubic inches contains:
Magnesium bi-carbonate. . .' 21636 grains
Calcium bicarbonate 48054 "
Sodium bi-carbonate 31196 "
Ferrous bi-carbonate 06205 "
Manganese carbonate trace
Potassium sulphate 20001
Sodium sulphate 05715 "
Sodium chloride 47704 "
Lithium chloride 03207 "
Sodium phosphate 00309 "
Soilinni arsenite trace "
Sodium bromide trace
Sodium iodide 00302 "
Silica 81645 "
Alumina 00898 "
2.66992 grains Carbon dioxide combined with monocar- bonates 27526 "
2.94518 grains Carbon dioxide free 9.96 cubic inches
OXIDES. 265
J following analysis by Professor J. W. Mallett of the water from the letta Springs, near Harrisonburg, Sockingham county, shows its dtion to be :
One United States gallon of 231 cubic inches contains:
Calcium carbonate 12.10 grains
Magnesium carbonate 5.78 "
Iron carbonate 3.12 "
Manganese carbonate 0.43 "
Sodium carbonate 0.93 "
Lithium carbonate trace
Ammonium chloride trace
Potassium chloride 0.13 "
Potassium sulphate 0.09 "
Oaldum sulphate 0.35 "
Alumina 0.13 "
Arsenious oxide (in salt) trace
Phosphoric acid trace
Silica 0.94 "
Organic matter 0.40 "
24.40 grains Carbonic acid united to carbonates as above to form acid salts 8.80 "
Temperature of water 55° F.
I analysis of the water from the Otterbum Lithia Springs, near a, in Amelia county, by Froehling and Robertson gave :
One United States gallon of 231 cubic inches contains:
Calcium carbonate 2.437G9 grains
Magnesium carbonate 1.48827 "
Iron (ferrous) carbonate 13646 "
Sodium carbonate 26009
Lithium carbonate 03615 "
Magnesium chloride 05656 "
Sodium chloride 40647 "
Sodium sulphate 08572 "
Potassium sulphate 08047 "
Sodium iodide 00609 "
Sodium bromide trace
Alumina 03616 "
SiUca 2.44352 "
7.47455 grains Carbon dioxide combined 2.38812 "
9.86267 grains Carbon dioxide free 18.4 cubic inches
n analysis made by Froehling and Robertson of the water from the
266 MINERAL RESOUBOES OF VIROINIA.
Swineford Arsenic Lithia Springs in Chesterfield county, near Richmond, gave:
One United States gallon of 231 cubic inches contains:
Magnesium bi-carbonate 0.14813 grains
Calcium bi-carbonate 0.11839 "
Manganese bi-carbonate 0.0042O <*
Iron (ferrous) bi-carbonate 0.02040 "
Calcium sulphate 0.10031 "
Potassium sulphate 0.16164 "
Sodium sulphate 0.11314 "
Lithium chloride 0.00385 "
Sodium chloride 0.34116 "
Sodium bromide trace
Sodium iodide 0.00021 "
Sodium arsenate 0.00723 "
Sodium phosphate 0.00340 "
Silicic acid 0.60067 "
Alumina 0.01083 "
Total mineral matter 1.64266 fprains
Carbon dioxide free 12.40 cubic inches
An analysis of the water from the Yellow Sulphur Springs, in Mont- gomery county, made by Professor William Gilham, gave :
One United States gallon of 231 cubic inches contains:
Calcium carbonate 8.64 grains
Magnesium carbonate 1.38 **
Iron carbonate 62 "
Calcium sulphate 63.30 "
Magnesium sulphate 21.10 **
Aluminium sulphate 3.18 "
Potassium sulphate 10
Sodium sulphate 76
Iron protoxide trace
Calcium sulphate 01
Magnesium phosphate trace
Potassium chloride 10 "
Sodium chloride 07 "
Organic matter 3.73 "
102.98 grains Carbonic acid 4.68 "
107.66 grains
The composition of the Wolf Trap Lithia Spring, at Wolf Trap Station on the Southern Bailway, in Halifax county, is indicated by the following analysis, made by Professor M. B. Hardin :
One United States gallon of 231 cubic inches contains:
Sodium carbonate 0.24027 grains
Lithium carbonate 0.01726 "
«
«
OXIDES.
267
Ammonium carbonate 0.00128 grains
Calcium carbonate 7.41222
Magnesium carbonate 6.09221 "
Strontium carbonate 0.38489
Iron carbonate 0.06007
Manganese carbonate 0.0134 "
Copper carbonate 0.001234 "
Sodium chloride 2.62956 "
Sodium bromide 0.00630 "
Sodium iodide 0.00066 "
Sodium nitrate 2.62648 "
Potassium sulphate 0.06366 "
Sodium sulphate 0.06007 "
Aluminium phosphate 0.04432 *'
Silica 2.01780 "
Barium carbonate trace
Zinc carbonate trace
Magnesium borate trace
Calcium fluoride trace
Titanic oxide trace
Organic matter (yielding ammonia) trace
20.66836 grains Carbon dioxide associated with the above carbonates in the so-called bi-carbonates 6.06682 "
Gases:
Carbon dioxide, free 12.38 cubic inches
Nitrogen 3.60 "
Oxygen 1.70 *'
17.68 cubic inches
Froduotion.
Of the 43 springs reporting sales, nearly four-fifths of the water Is used for medicinal purposes. About half the total number of springs are used as resorts, having accommodations for several thoufiand people. At a number of the springs the water is used for bathing purposes. Among the most celebrated waters on the continent for bathing purposes, are those of the Warm Springs, in Bath county, a view of which is shown in plate XXXVIII, figure 1.
Year.
1900. 1901. 1902. 1903. 1904. 1906.
Number of springs reporting.
38 41 48 41 35 37
Product in gallons.
1.141,859 1,562,781 2,442,398 2,561,502 2,117,420 2,340,287
Value.
$272,868 835,869 423,412 477,410 281,998 549,102
268 MINERAL RESOURCES OF VIRGINIA.
Keferences.
The literature relating to the mineral springs of Virginia is very ex- tensive; only several of the more important ones are here noted.
Froehling and Robertson. A Hand-Book Prepared for the Virginia Com- mission to the Saint Louis Exposition. Richmond, Virginia, 1904, 97-159. Contains a large mimber of analyses of Virginia iniueral waters.
Peale, A. C. Mineral Springs of the United States. Bulletin No.
32, U. S. Geological Survey, 1886.
The Natural Mineral Waters of the United States. 14th Annual Report, U. S. Geological Survey, 1894, Part II, 53-88.
See also the annual volumes of the Mineral Resources of the United States, published by the U. S. Geo- logical Survey.
Rogers, Wm. B^ Mineral .Springs of Virginia. A Reprint of the
Geology -of the Virginias. New York, 1884, 549-566.
, > •. • • . •
Artesian. Waters. *--The underground or artesian waters are treated only for onie province of the State, namely, the Coastal Plain or Tidewater region, for the reason, that, unlike the other two larger provinces, there are no large supplies of portable surface water found within the region. The rivers which traverse the region are either tidal estuaries or are widely bordered by swamps, and the water of their local branches is often of bad quality.
Tidewater Virginia extends eastward of a line passing through Alex- andria, Fredericksburg, Richmond, Petersburg, and Emporia, and com- prises an area of about 9,500 square miles. The general structural rela- tions in Tidewater Virginia, so far as they are known, are shown in the sections on plate XXXIX. The Coastal Plain formations which outcrop in the State are as follows :
Formation. Characteristics.
Age.
Columbia ; Loams, sands, and gravels in terraces
Lafayette...... Orange sands, loams, and gravels
Chesapeake Clays, sands, diatomaceous earth, and marl.
Pamunkev Glauconi tic marls and sands
Potomac. Sands, sandstone, and clays
Pleistocene.
Pliocene (?)
Miocene
Eocene.
Early CreUceom.
'Compiled from various j)apers published by N. H. Darton and M. L. Fuller. The water resources of the Virginia Coastal Plain are being carefully studied by the U. S. Geological Survey and a report formulated. This report, when published, should
(•ontniii mucli u-^eful information Ihat is of practical value.
MINSRAI^ RBSO
q
•MH
' - I
! •
After X. H. Diin.iii..
OXIDES. 269
WATER HORIZONS IN EASTERN VIRGINIA.
According to Darton, the greater part, if not all, of the Coastal Plain r^on of Virginia is underlain by water-bearing strata, of which, to the eastward, there are several horizons. The failures to obtain the higher water in some of the wells near the bay indicate that in this area at least, there are no good water supplies in the higher horizons, but the waters of the lower horizons have not yet been fully developed. The success of the new well at Fort Monroe definitely proves the existence of one of these.
The principal water horizons in eastern Virginia are the Chesapeake, Pamnnkey, and Potomac formations, shown on map, plate XL.
Potomac. — There is more or less water in all of the coarser sand beds of the Potomac fonnation, but the principal supplies may be expected from the sands and gravels of the basal members, lying on the basement floor of the crystalline rocks. This horizon has been well explored about Wash- ington and Alexandria, in most cases with great success, and was probably reached by the 210-foot well at Quantico. South of Quantico for some distance it does not appear to have been reached by any of the wells except one at Walkerton, on the Mattapony river ; but from the general character of the formation as exhibited in its outcrops, and its productiveness of water northward, Darton says there is reason to believe that it is a great water-bearer throughout a wide extent. Its general relations are shown in the sections on plate XXXIX. How far eastward the coarse materials extend in the basal beds of the Potomac formation is not known, for they lie deeper than any of the wells appear to have penetrated. The North Point well is reported to have reached granite and found no water supply in the basal beds, but as elsewhere explained by Darton, the record and conduct of this well do not afford conclusive evidence either of the actual absence of water or of the presence of granite at the bottom of the boring. Tlie well, no doubt, reached the Potomac formation, and it may have penetrated far into it. The water at the Chamberlain Hotel at Fort Monroe is fhonght to be from upper Potomac but the evidence is not conclusive as to the precise horizon.
Water occurs at various horizons in the Potomac formation above ihc basal beds, in sands intercalated amiong the clays. This water is an im- portant source of supply in the District of Columbia, and it also affords a large yield at the well at Barrow, near Quantico. Only one of the wells aoufh of Fredericksburg has penetrated to these waters so that their ioiifheastem extension has not been well explored, but there is a fair
270 MINERAL RESOUBCES OF YIBOINIA.
possibility of finding one or more of them in that region. The 600-foot boring at Gloucester may have reached the Potomac beds, and even pene- trated them for some distance, without finding water, but as this boring missed the higher waters that probably underlie Gloucester, it cannot be regarded as a decisive test for any of the waters.
Pamunkey. — The coarse gravel and sand at the base of this formation appears to extend far to the east, and it is a water-bearer throughout its extent. It was reached by the deep well at Naylor's Wharf at a depth of 386 feet, where sands with rock layers yielded a large flow of water which rose to 45 feet above tide-level. At Chapel Point, Maryland, at 237 feet, in the several deeper wells at Colonial Beach, at Lester Manor, at a depth of 200 feet, and at White House at a depth of from 180 to 230 feet, it fur- nishes a large supply of fine water under considerable pressure. These wells indicate a wide extent of the waters in a r^on which probably comprises the western half of the area indicated by a distinctive pattern for Chesapeake and Pamunkey waters on the map, plate XL. This horizon is about 260 feet below the Chesapeake water. The meager supply of water in the Clay Bank well and the failure of the deeper borings at William«- burg and Gloucester probably indicate the limits of the horizon as a water-bearer to the eastward. It may extend under all of the region south of the James river, but none of the wells appear to have been bored suffi- ciently deep to reach it and higher waters are utilized. The experience of thi unsuccessful boring to a depth of 386 feet at Dendron is not conclusive, for it probably did not reach the horizon, and if it did, may not have prop- erly tested it; still, it is in line with the experience at Williamsburg and Gloucester. The latter criticism applies also to the North End Point well It is to be expected that to the eastward the materials of this horizon fi- nally become too fine-grained to carry water, and the eastern limits of conditions favorable for water-bearing appears to be at Clay Bank on York river.
Water also occurs in sands in the Pamunkey formation about 90 feet above its base aa indicated by the water at 160 feet at Colonial Beach, and at 276 to 325 feet at Naylor^s Wharf; but as it has not been further ex- plored by other wells its extent cannot be discussed.
Chesapeake, — Lying between the clays, marls and fine sands of the Chesapeake formation and the top of the Pamunkey formation, there is a series of sands and gravels which may be regarded as the basal bed of the Chesapeake formation. To the eastward, this series contains thin inter- stratified rock strata which do not appear in the surface outcrops. In this
OXIDES. 271
series and in another similar one not far above, there is a large volume of water at a horizon or horizons which appear to be of wide extent in eastern Virginia. These waters have been explored by many wells and been found to underlie a belt of country about 20 miles in widths lying cast of a nearly strai^t line extending from Mathias Point on the Potomac river to Em- poria on the Atlantic Coast Line Bailway. This belt has been indicated on the map, plate XL, by a distinctive pattern, and the relations of the waters are shown in the sections on plate XXXIX. The wells which reach these horizons in Virginia are given in the foUowing list :
Locality Depth Remarks
Richmond County Feet
Naylor's Wharf 135
Sharps' Wharf 236
Lanoasteb Gountt
Monatico Creek 250
Whealton 230
Monaskon
Laneaater 250
Garten Creek 830
Weema 260
T^ndmill Point 450 Well blocked by breaking of tools.
WB8Tlf0REI.AND COUNTT
Coles Point 220
Bagged Point 225
Sandy Point 235
Northumberland Countt
Kinsale 235
Lewisetta 317
Cowart 238 Water also at 270 feet.
Fairport 393
I>7mer Creek 443
Mattapony River
Littie Plymouth 168
Sheppards Warehouse 160
York Riter
Dudleys Ferry 175
West Point 160
Plum Point 168
Gables Mill 226
Bellevue 212
Puritan Bay 215
Jambs Riter
Williamsburg 280
Homewood 290-317
Jamestown 248
Courtland 160 Horizon doubtful.
Arringdale 78 Horicon doubtful.
272 MINERAL BE80UB0E8 OF VIBGINIA.
The horizon of the waters at 130 feet at Franklin, 161 feet at Zuni, and 190 feet at Mount Carmel is not certainly known, but it is thought to be in the Chesapeake fonnation considerably above its base. The Ar- ringdale well at 76 feet and the Courtland wells at 160 feet are doubt- fully referred to the basal Chesapeake beds, but the former may be do^ to a lower horizon.
Basal Chesapeake waters were apparently absent in the North End Point, Fort Monroe, Dendron, Clay Bank, and Gloucester wells.
There are several higher horizons of water in the Chesapeake forma- tions and it is believed that the wells at Franklin, Zuni, and Mount Cannel are from Chesapeake beds about 100 feet above the base of the fonnation. The water of the Bowlers Wharf well at 143 feet is from about the same horizon, but water reported at 240 feet in the Djrmers Creek well is some- what higher than the others.
The salty water at 606 feet at Lambert Point and at 599 feet at Fort Monroe, and the ferruginous water at 662 feet at Money Point, all near Norfolk, are from somewhat higher horizons. The waters at 140 feet at Onancock on the eastern shore and at 70 feet at Virginia Beadi are at still higher horizons. Darton states that he is not inclined to r^ard any one of these upper Chesapeake horizons as widespread, and with our pres- ent meager knowledge they cannot be predicted with safety.
WELLS IN EASTERN VIRGINLA..
Reference to the map, plate XL, will show a reasonably large number of wells in eastern Virginia most of which have obtained abundant sup- plies of water at very moderate depths. Numerous wells have been pot down in the area since the publishing of this map in 1896, the records of which have not been available to me for this book and hence are not in- cluded on the map.
The following is a list of deep wells in eastern Virginia published by Darton in 1896.
OXIDES.
273
Partial List of Deep Wells in Easieni Virginia,
Location.
; Depth.
AlexAndiia Brewery ... Alexandria Ice Works
Airlngdale, 2 wells
Ashland Ashland
Belteme, 2 wells..
BotbwelL
Bowlers Wharf...
Oftrters Creek
Clay Bank..
CUnon,2well8..... Ooan, Swells.
Ooan,lwell
Coles Point.
Colonial Beach, 5 wells
Coartland, 30 weUs.
Cowart
Ditchley
Dendron „
Dudleys Ferry, A wells Dymer Creek
Fairport
Fort Monroe
Fort Monroe, Cham- berlain Hotel
Franklin. 16 wells
Qabel's BIIU
Oloncester Ct. House
Homewood, 5 wells..
Jamestown
King and Queen. Klnsale
430 401
76
79 100 195
212 300 143 330 588 175 270
315 220 250
160 288 620 386 175 443
308K 907
945
130 226 600
817
112
248 200 285
Size.
In,
8 8
i^
4
}^
2
IH
IH
IK
1
3 2
IK
Capacity per minute.
OiMong,
90 20
Flows 10
Many. Many. Many.
Flows 15-20
20
7
Flows 2 Flows 10-12 Flows 2H
15 8 5
30 Flows 2 Flows 2 None. Flows 10 Flows 7
Flows 2 None.
Flows 50
Many.
Flows 20
None.
Flows 50
Fair supply.
Flows ^ Flows 1 5
Height
to which
water
rises, a.
FeeL
-12 +10
44tOi«
+ 7 Flows.
+12
+ 4 +410-1^
+12
+12
+12
fSto+lS
+ 6 4to 6
4 to 6
+10
Flow. +10
+ 2
+16'
Horizon.
Basal Potomac
Granite (?)..
Granite
In Potomac.
Basal Chesapeake
Newark
Chesapeake
do
Basal Pamunkey
do
Basal Chesapeake
do
do
Basal Pamunkey.
Che8apeake(?)
Basal Chesapeake
Basal (^hesapeake Basal Pamunkey..
Basal Chesapeake Potomac(?)
do
Chesapeake
Basal Chesapeake Pamunkey (?)
Basal Chesai>eake
Chesapeake.
Basal Chesapeake Basal Pamunkey Basal Chesapeake
Remarks.
Soft water. Poor water at 300
Slightly alkaline water.
No water below 148 feet.
Soft water.
Water also at M> feet
Water also at 160 feet.
Nowater4M"607H feet; water also at 240 and 464 ft.
Soft, good water.
Slightly saline water.
Stopped at rock
stratum. Fine water 64©; Sulphurous
water at 270 ft. Femiginoui
water. Fine water 68o.
a +, feet above the surtbce; — , feet below the surflEu«.
HINSEAL BE80UH0B8 OT TISOINIA.
|
List of Deep Wells |
||||||
|
Location. |
DoptJ.. |
Hlie. |
ppr minuto. |
•"SE?" |
Hortson. |
,^,„ |
|
1 S Z si '« 140 z m § wo flOO 2S0 aas MO MO («) 100 BSD ItU-^IU *.■» Ifll |
7n. |
Flows 12 |
J"k«(. |
Bual Cli«Bpatk< |
||
|
Letter Mraor. 8 welLi |
U |
FlowBia |
+8 to +12 |
g2S!?!.S2ffe |
||
|
a |
Flows S |
BosbI (niaiaii^iat |
||||
|
'1 |
Flows 1) Flows » Mows 10 Flows 10-12 Flows 10-12 |
+ 2 |
||||
|
Mount Csnnel Church.... |
£~fiiEi= |
|||||
|
AT |
t S |
do |
^^r;?sr |
|||
|
11 |
do |
|||||
|
Sr^'SJil"'" " |
48-12 |
PotoDW- |
WBUT |
|||
|
i! li |
Non« FlSwB 1W2 None Soae SitisIhclorT auHBdictoiy Flows ia.% |
|||||
|
K™i%;i;it;: . .■■:■.;■,■.■....■,■..■ |
+18 |
|||||
|
inallai |
||||||
|
Bherwood PBrk." 1 mile |
^ |
|||||
|
BnaHy Polnl; RilrtUi County .'.' Bhartf. Wlwrf. |
+12 +2* |
No wntM Wlo« iTOff^trwliiil)- |
||||
|
ShepiHrd'B Wawhouw. |
+** |
■JlOftel |
||||
|
ChesapeBke '. |
||||||
|
Knlr supply |
||||||
|
+4-8 |
water |
|||||
|
BiunlCbera^^e Cbll^p^kl. |
||||||
|
"Wert PoiHt, 200 wel'li' |
li |
Average li |
||||
|
^•iiSrS;:;^^-"' |
K |
|||||
|
|
mcumniioi |
|||||
|
Znnl |
Flows 2 |
OXIDES. 276
Beferenoes.
le following list includes the principal publications which bear on Qderground waters of eastern Virginia:
n, N. H. Artesian Well Prospects in Eastern Virginia, Mary-
land and Delaware. Transactions American In- stitute of Mining Engineers, 1906, XXIV, 372-397.
Artesian Well Prospects in the Atlantic Coastal Plain Region. Bulletin, TJ. S. Geological Survey No. 138, 1896, 162-190.
Preliminary List of Deep Borings in the United States. Water Supply and Irrigation Paper, TJ. S. Geological Survey No. 61, Part II, 60.
Geologic Atlas of the United States. Fredericksburg, Virginia Polio, No. 13. U. S. (Jeological Survqr, 1894.
Geologic Atlas of the United States. Nomini Folio, Maryland and Virginia, No. 23. U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Norfolk Folio, Virginia and North Carolina, No. 80. U. S. Geo- logical Survey, 1902.
and Keith, A. Geologic Atlas of the United States. Wash- ington Folio, District of Columbia, Maryland and Virginia, No. 70.. U. S. Geological Survey, 1901.
and Fuller, M. L. Underground Waters of Eastern United States. Water Supply and Irrigation Paper No. 114, U. S. Geological Survey, 1905, 127-135.
V. SILICATES.
1. FELDSPARS.
Composition and Character.
le feldspar group includes a number of mineral species which chemically, silicates of aluminum with varying amoimts of
and the alkalies, potash and soda. The species belong- 9 the feldspar group are alike in having two easy cleavages along
they split with even, smooth, and shining surfaces, and are inclined 5 another at right (90**) and oblique angles. In color they vary from
276 MINERAL RE80UB0E8 OF YIBGINIA.
colorless through white, gray, pink, red, and green; and they vary from transparent through translucent to opaque, the latter being the more fre- quent. They crystallize in the monodinic and triclinic systema. In hard- ness, they vary from 6 to 6.6, and in specific gravity from 2.6 to 2.9.
Ocenrrence.
Of the nine known species of feldspar only a few are of com- mercial value; the principal ones being the potash varieties, oithodase and microcline, and the soda variety, albite. The commonest species of feldspar is orthoclase, and it is the one commonly used by potters in this country. It is the most infusible member of the feldspar group. The feldspars are common constituents of certain types of rocks such as the granites, gneisses, and syenites, but as such they have no commercial value.
Commercially valuable feldspar occurs associated with quartz and mica as coarse crystallizations in pegmatitic dikes or veins, cutting graniteB, gneisses, and crystalline schists. In addition to quartz and mica, a great variety of rarer minerals are associated with the feldspar in the pegmatite dikes a list of which, for the Amelia coxmty, Virginia, area, is given on page 282.
Distribution.
Pegmatitic dikes, containing feldspar as an important constit- uent, are quite widely distributed through the Virginia crystalline or Piedmont area, east of the Blue Ridge, where they are found pene- trating the principal types of the older rocks of the area. Hardly a county within the Piedmont area is without them. Notwithstanding the abundance of these dikes in the middle province of Virginia, many of which contain commercially valuable feldspar, the attempts to mine this mineral are comparatively few and as yet the production is small. Up to the present time, the principal area in the State in which feldspar has been mined is in Amelia county, in the vicinity of Amelia courfc-house. Here the feldspar has been mined in connection with mica and a full de- scription of the Amelia county pegmatite masses is given under Mica on pages 280-284.
In the feldspar-mica pegmatite dikes of Amelia county the potash varieties, orthoclase and microcline, and the soda variety, albite, occur. These are in large masses, usually of a high d^ree of purity, and white in color, though green is not uncommon. The following analyses of samplfiB of these three varieties of feldspar from the Amelia county area show their composition to be :
8ILI0ATE8.
277
Percent
II Per cent
III Per cent.
SiUea (SiO,)
Alumina ( Al,Ot)
Iron oxide {Yefit) . .
Lime (OaO)
Magnenia (MgO)
Potash (K.0)
Soda (Na,0)
Total
Spedflc gravity
|
66.37 |
64.12 |
|
18.74 |
16.84 |
|
0.13 |
2.28 |
|
0.27 |
0.32 |
|
0.26 |
|
|
12.98 |
13.34 |
|
2.49 |
1.88 |
|
99.98 |
99.04 |
|
2.601 |
2.664 |
67.06 21.72
1.69
0.03
0.38
10.01
100.79 2.618
I. Ortboclase. E. B. Sloan, analyst. II. Microcline (Amazonstone). C. C. Page, analyst. IIL Albitei Bobert Robertson, analyst.
Mining of feldspar^ in an extensive p^matite, was recently b^^ on Otter river, about 3 miles southeast of Bells, in Bedford county, by the Bine Bidge Kaolin Company. The product is shipped to East liyerpool, Ohio, ioft use in pottery manufacture.
Uses.
The chief use made of feldspar is in the manufacture of pot- tery, wall and floor-tiles. For pottery-making, the feldspar is mixed in a finely pulverized condition with the kaolin or clay. It is also utilized to some extent in the manufacture of wood-fillers, scouring soaps, and glass.
Beferences.
Musgrave, B. N.
Page, C. C.
Robertson, R
Sloan, B. E.
Analysis of Beautifully Crystallized Albite from near Amelia Court House, Virginia. Chemical News, 1882, XLVI, 204.
Amazonstone from Amelia County, Virginia. The Virginias, 1886, VI, 24-25.
Albite from Amelia County, Virginia. The Virginias, 1885, VI, 25.
Analysis of the Feldspar Accompanying Microlite in Amelia County, Virginia. Chemical News, 1881, XUV, 207 ; The Virginias, 1882, III, 4.
278 MINERAL RESOUBOES OF VIBGINIA.
2. HICA.
GENERAL CHARACTER AND COKFOSITIOH.
Under the mica group is comprised a nnmber of distmct mineral species which are alike characterized by highly perfect basal cleavage, parting readily into very thin, tough, and more or less elastic, sheets that are translucent to transparent. In most cases, they are chemically orthosilicates of aluminum with principally hy- drogen and potassium or sodium, lithium, magnesium, and iron. Of the seven species of mica, only two are of commercial value, though a third one, lepidolite, may be a source of lithia salts, but it is not used for any of the purposes of a conmiercial mica. The other two micas, muscovite and phlogopite, comprise all the commercial mica that is marketed; and in the United States only muscovite is mined, because there are as yet no known commercial deposits of phlogopite. Muscovite is the white potash mica and phlogopite is the pearl gray magnesian mica.
GCCITRRENCE.
Muscovite, the white mica, and biotite, the black mica, are very widely distributed and are among the commonest constitaents of many of the crystalline and sedimentary rocks. It is only when muscovite occurs in blocks or masses of size that will split into sheets an inch or more in diameter that it has commercial value, which increases with the size of the cut sheets. Usually the commercial deposits of mica are found in pegmatitic dikes or veins of coarse crystallization, which penetrate gran- ites, gneisses, and crystalline schists. In small veins the mica is fre- quently too small in size to have commercial value.
Quartz, feldspar, and muscovite are the principal minerals composing the pegmatite dikes. As a rule, these minerals are not uniformly distri- buted through all parts of the dikes, but, on the contrary, their distribution is very irregular, with first one and then another of the three minerals predominating in different parts. Besides the three principal minerals mentioned, there are large numbers of rarer minerals found in the pegma- tite dikes, some of which occur only sparingly, others more abundantly. Some of these have commercial value as gem material, such as garnet and beryl, which occur in the Amelia county, Virginia, dikes and have been used for gem purposes.
Likewise, the quartz and feldspar of the pegmatite dikes are of value and are sometimes mined with the mica and utilized in the manufacture of pottery and for abrasives. Both the principal and accessory mineraU
8ILI0ATB8. 27^
enumerated above have been mined and marketed from the Amelia county, Virginia, area. In addition to these, the Virginia dikes have been a source of some kaolin, derived from the decay or kaolinization of a part of the feldspar in that portion of the dikes above the level of local groimd water.
DISTBIBTmOH AND DESCBIPTIGH.
From the description given above of the occurrence of mica, it follows that the distribution of this mineral in Virginia must be limited to the crystalline area or Piedmont Plateau, east of the Blue Bidge. Pegmatite dikes containing mica are somewhat abun- dantly developed over the Virginia crystalline area and many ex- cellent surface indications for mica occur, but as yet prospecting and min- ing have been limited. Of the large number of counties in the Virginia area, mica has been either prospected or mined in the following: Amelia,- near Amelia court-house, and near Jetersville; Bedford county, near New London on the John P. Thompson place; Goochland county, near the court-house where it was mined in a small way but afterwards abandoned on account of the influx of water; Pittsylvania, south of Chatham; Am- herst; Henry county, at Bidgeway; and Hanover county, near Hewlett^s biation. The Hanover mine near Hewlett^ s has not been worked since 1872. In addition to the above, surface indications are noted in Powhatan, Cumberland, Caroline, Buckingham, Spottsylvania, and Franklin counties. Mica occurs in Franklin county in Snow creek valley on the south side of Chestnut Mountain.
At Bidgeway in Henry coimty, the Pittsburg Mica Company is engaged in developing a mica property. A commodious plant has been built and the^ development work comprises an open cut about 100 feet long and 40 feet deep, and about 1,000 feet of cross-cuttings. The dike is about 8 feet wide. The company expects to begin shipping mica not later than Sep- tember, 1907.
Of the many localities where mica is found in Virginia only one has yet been seriously mined, namely, near Amelia court-house and near Jetersville, in Amelia county. Because of the prominence of the Amelia county area, it is here described in some detail.
THE AMELIA COTTinr? AREA.
Mica mines have been opened at two localities in Amelia county, both of which are in close' proximity to the Bichmond and Danville division of the Southern Bail way. These are (1) in the vicinity of Amelia court- house, and (2) near Jetersville about 8 miles south of west from Amelia
280 MINERAL REBOURCES OF VIRGINIA.
court-house. The general topography of the two areas and location of the mines are shown on the map^ figure 42.
Amelia Conrt-House District
Openings from which mica has been mined and smaller pits are abun- dantly developed over an area stretching northeast from Amelia court- house for a distance of 2 or more miles. So far as the writer can ascer- tain, the first mining of mica in this district was begun about 1873 on the Jefferson property described below. Mining has continued at intervals from 1873 to date, but in the summer of 1906 only one mine, the Pinch- back, was operating.
The principal mines in this district which have produced mica are the Jefferson, Rutherford, Berry, Winston, and PinchbacJc, Most of these have been idle for the past 10 or 12 years and many of the openings which are reasonably large had been abandoned for so long a time at the time of my visit in July, that they had largely fallen in and were partially filled with water. The deepest would probably not exceed 100 feet, the work having all been surface mining, comprising cut and pit excavations.
Both sheet and scrap mica were produced at these mines. Some of the sheets measured after cutting as much as 12x14 inches. No sheets were cut smaller than 2x2 inches in size and all mica under this size was marketed as scrap.
GENERAL GEOLOGY.
As may be seen by reference to the map, figure 42, the surface of this district is a moderately undulating one without con- spicuous elevations or depressions. The principal rock is a biotite gneiss of thin foliation not infrequently showing a distinct "augen** texture. It is quite dark in color from the presence of much biotite and is fine-grained in texture. Its origin is yet undetermined, whether an original igneous or sedimentary mass.
The mica occurs as a constituent of the pegmatite dikes whidi inter- sect the biotite gneiss of the district. It is found as a coarse crystalliza- tion with feldspar and quartz. The openings made on these dikes show a •very variable ratio of the three principal minerals, mica, feldspar, and «qiuurtz. In places, the three occur in nearly equal amount; in otfaers, domi- aumt feldspar and mica with very little quartz; and others still show daminant quartz and mica with little or no feldspar. The feldspar of ikas indude the potash varieties, orthoclase and microcliney and
282 MINERAL RE80UB0ES OF VIBGINIA.
the soda variety, albite, description and analyses of which are given on pages 276-277.
In addition to the three principal minerals, a large number of rarer minerals have been noted in the Amelia county p^matites. These are microlite, fluorite, columbite, helvite, monazite, allanite, spessaritite (ga^ net), apatite, beryl, tourmaline, and zircon.
The rocks are everywhere mantled by a considerable depth of residual decay. Accordingly outcrops are rare, and since the openings, on account of long standing, show much caving from the sides, exact measurements of the dikes could not be made. As nearly as could be determined, the larger pegmatite dikes will measure more than 50 feet across, and they usually cut across the foliation of the enclosing or country rock. These dikes are not schistose but entirely massive and are cut by jointing.
The mica occurs as thick highly cleavable blocks and masses of vary- ing size. That found on the dumps is invariably of light, white color, but in some of the openings the mica is very dark in color, nearly black. For a description of the feldspar and quartz contained in these dikes see pages 275-277.
MINES.
The Jefferson mines, — These were the first mines opened in the dia* trict and a large number of openings have been worked, the extreme north- east ones being about 2 miles N. 30° E. from Amelia court-house. Some of these openings are among the largest made in the district, and none of them have been worked for many years.
The Rutherford mines. — The Butherford mines are located 1 mile N. 30*" E. from Amelia court-house and are reported to have been first opened about 24 years ago. Two openings were worked, aligned in a nearly north-south direction, and are separated by a distance of about 100 yards. The last work done is reported to have been about 12 years ago. Mud green feldspar occurs though the bulk of this mineral is white. The largest sheets of mica mined are reported to have cut 22x24 inches.
The Berry mine. — This mine comprises one large and deep ronghly circular opening, immediately on the southeast side of the Southern Bail- way, about 1 mile northeast of Amelia court-house. No work has been clone for many years.
The Winston mine, — The Winston mine is located on the north side of the Southern Railway about one and three-quarter miles N".70**E. froifl Amelia court-house. The principal opening is a large one and has not been worked in recent years.
MINERAL BB80URCE8 OP VIRGINIA.
Hhowing width of
."-iV'^fe.-?^^''
-■:~W^
Vi^i, 2. — View (if liunip iif scrap mien, near Amelia (-oiirt-liouse. MICA MINE ANT) DUMP. AMELIA COUKTY, V[RG1NIA.
8ILI0ATES. 283
The Pmchhack mine. — ^This was the only mine operating in the county in 1906. It is located abont 2 miles northeast from Amelia court-house and about one-qnarter of a mile southeast of the extreme opening on the JeffenoQ place. It was first worked about 18 years ago. Some half dozen or more openings have been made, the most recent one of which was made in the spring of 1906, and in July it had been worked to a depth of 28 feet Plate XLI, figure 1, is a view of this opening. As exposed by this opening, the dike is about 40 feet wide composed of white feldspar and quartz and dark-colored mica and an occasional beryl crystal. Be- tween the middle of the dike and the walling, the feldspar is entirely kadinized to the depth of working, 28 feet, and much high grade kaolin is being removed and shipped. The feldspar is all partially kaolinized throughout the depth of working, and it rapidly slakes on exposure to the air. It is all saved and shipped to Trenton, New Jersey, where it is util- ized in pottery manufacture. The largest sheets of mica taken out meas- ured 12x14 inches after cut. The average size is probably about 4x6 inches and much of it cuts only 2x2 inches. Both sheet and scrap mica are pro- duced.
The Tetersville District
This area as shown on the accompanying map, figure 42, is 8 miles south of west from Amelia court-house.
The SchlegcU mine, — Only one mine has been worked in this district, the Schlegal, which is located three-quarters of a mile N. 80® W. from Jeters- ville. It was worked by shaft and open-cut and was first opened about 24 years ago, and was last worked about 5 years ago. The shaft was worked to a depth of 100 feet with several drifts run from it.
The country rock comprises a gneiss of granite composition and a frheared, thinly schistose diorite. As measured at the top of the open work, the pegmatite dike containing the mica will not exceed 30 feet in width. The openings are apparently made in a curved or bent portion of the dike the two parts of which strike N.70°W. and S.20°W. The pegmatite cuts across the foliation of the country rock which at the openings strikes nearly north and south.
About a half mile N. lO"* E. from the shaft, continuous exposures of a large pegmatite dike trending north-south are traced along the valley side of a small stream. No openings are made on this dike and it is re- garded as a separate one from that on which the mine is opened.
284 MINERAL RESOURCES OF VIRGINIA*
A mill for grinding and crushing the feldspar which was shipped for use in pottery manufacture was operated at the mine. Blocks or masses of mica yielding cut-sheets of 8x12 inches are reported mined. The mica seen at the time of my visit in July was dark in color. In addition to the three chief minerals^ quartz, feldspar, and mica, all of which were marketed, numerous small crystals of red garnet occur.
Uses.
Until within recent years, almost the only use made of mica was as cut sheets of different sizes in the doors or windows of stoves and furnaces, and in other similar places where transparency and resistance to heat were the essential qualities. During this period the small pieces and waste in mining and in cutting the sheets could not be utilized and were thrown away. At the present time, however, the demand for mica for electrical purposes is great and much of the small pieces that were formerly thrown away are now cut into small circular disks and rectangu- lar pieces for insulation purposes in electrical apparatus.
The large amount of scrap mica, 75 to 90 per cent, in mining, which was formerly thrown away is now saved and used in the form of groimd mica. The mica is usually ground to five sizes to pass through sieves of 80, 100, 140, 160, and 200 meshes to the inch, respectively. This ground mica is now utilized for a great variety of purposes, the principal ones of which are in the manufacture of fire-proof materials, chiefly paint; as a nonconductor for steam and water heating; as a lubricant; for decora- tive purposes; and in the manufacture of paints.
Production.
Almost the entire production of mica in Virginia has been from the Amelia county area. In some years the production from the mines of this area was quite appreciable but during the present year only one mine was in operation. Mica-mining in Virginia has been so irregular that accurate figures of producton are difiBcult to obtain. The years given below while not consecutive will probably afford some idea of the annual mica-production in the State:
Year. Pounds.
1886 1,500
1887 3,600 1900 16,000 1902 96,000
SILICATES. 285
Sefereneet.
Campbell, J. L. The Steatite, Mica, Pire-Claj-s, Barytes, Etc., of James
River Valley. The Virginias, 1882, III, 160.
Fontaine, W. M. Mineral Besources of Blue Ridge Plateau. The Vir- ginias, 1883, rV, 179.
MerriU, G. P. The Non-Metallic Minerals. New York 1904, 163-
180.
Pratt, J. H. Mica. The Mineral Besources of the United States
for 1904, 1175-1184. See also other volumes of the Mineral Besources of the United States.
3. ASBESTOS.
Composition and General Character.
The name asbestos was originally applied to a fibrous variety of the mineral amphibole, which is a normal metasilicate of cal- cium and magnesium, with frequently varying amounts of iron and manganese and, at times, smaller amounts of the alkalies. As now used, the term properly includes the fibrous varieties of the mineral serpentine, a hydrous magnesium silicate. These two miner- als, the fibrous varieties of amphibole and serpentine or chrysolite, form the present sources of commercial asbestos. They are similar in their physical properties but are distinct chemically. Though equal in their heat-resisting properties, chrysolite is superior in strength and elasticity of fibre to any of the amphibole asbestos. The most marked character of asbestos is its fibrous structure. Chrysolite asbestos is usually greemsh- white, yellowish to brownish in color, and has a pronounced silky luster. The amphibole asbestos varies from white to greenish and woody-brown. Its fibres are longer than chrysolite and are flexible and easy to separate.
Occurrence.
Asbestos occurs in those r^ons composed of the older eruptive and metamorphic rocks; hence the deposits of Virginia are lim- ited to the Piedmont or crystalline area, east of the Blue Ridge. The amphibole asbestos is usually found m granite or schistose rocks either in pockets or in more or less well-defined veins, a fact which considerably lowers the cost of mining it. The chrysolite or serpentine asbestos is always found in serpentine rocks not in regular veins but as irregular seams which necessitate the mining of a large amount of rock in order to obtain a small amount of the mineral. Amphibole asbestos is less valu-
286 MIKBBAL RESOUBOES OF VIBGINIA.
able. It is more easily mined, and where the strength of fibre is not essen- tial it is as satisfactory as the more expensive and rarer chrysolite asbestos. In Albemarle county, Virginia, asbestos is found in thin platy masses along slickensided zones in steatite (soapstone from altered pyroxenite), the fibres of which are parallel to the direction of movement.
Distribution.
So far as is known the asbestos found in Virginia is of the amphibole variety. It occurs in many of the Piedmont counties of the State and in a few it has been prospected and mined. Bedford is the only producing county at present. In Amelia county about 7 miles north of west from Mattox station, asbestos has been mined near the Appo- mattox river. A very promising grade of the mineral was opened some years ago in this vicinity on the Ligon place. It is found in the vicinity of Whitehall, and Willis Mountain in Buckingham county; and at several points in Powhatan and Gfoochland counties, although it has not been de- vdoped in any of these localities.
About 2 miles east of Rocky Mount, in Franklin county, asbestos of excellent grade has been mined to a limited extent. It is associated with soapstone in the form of pockets, is of the amphibole variety, and has a long and white silky fibre.
The only producing property at present in the State is that of the American Asbestos Company near Chestnutford post-oflBce, in Bedford county. A number of veins or seams varying from 8 to 50 or more inches wide are worked. The company has recently completed a 40-ton plant erected for the purpose of crushing and separating the asbestos. A con- siderable amount of the crude rock has been mined.
Asbestos has also been noted in Floyd, Grayson, and Fauquier counties, hut, a5 yet, it has not been worked in either of these counties. As stated alfovt it is found in Albemarle county in thin platy masses in the soap- SrWne of the Alberene lead, and is of the amphibole variety. Professor B. L. Packard analyzed a specimen of the amphibole asbestos from Albe- xoark county, which gave:
Per cent. Silica (SiO,) 56.26
Alumina (A1,0«) 181
Iron oxide (FeO) 6.40
Manganese oxide (MnO) trace
Lime (CaO) 11.98
MagiMaia (MgO) 20.85
Ignition 2.65
Total 99.96
siucATfis. 287
Doctor Merrill gires the following aiial3r6is» made bj Packard, of an amj^bole asbestos from Boanoke county, Virginia :
Per cent.
Silica (SiO,) 55.81
Alumiiim (AlA) 106
Iron oxide (FeO) 6.81
LiiTO (OtO) 12.74
Magnfia (MgO) 21.09
Ignition l.Sl
Total 99.92
TTses.
The uses of asbestos are many and varied and are constantly increas- ing. Where the chief requirement to be met is non-conductivity of heat, the amphibole asbestos is ordinarily used, but where strength of the fibre is an essential as well as non-conductivity of heat, the chrysolite va- riety is used. Amphibole asbestos is largely used as an ingredient in fire-proof paints for wall plasters, boiler covering, packing in the manu- facture of fire-proof safes, etc. The chrysolite variety is used in the manu- facture of cloth, rope, felt, boards, tubes, washers, etc.
Beferences.
Campbell, J. L. The Steatite, Mica, Fire-Clays, Barytes, Etc., of James
River Valley. The Virginias, 1882, III, 160.
Fontaine, W. M. Mineral Resources of the Blue Ridge Plateau. The
Virginias, 1883, IV, 178-180.
Merrill, George P. The Non-Metallic Minerals. New York, 1904.
Day, David T. Mineral Resources of the United States for 1900,
1901, 1902, and 1904.
4. GABNET.
Composition and Properties.
The garnet group comprises a half dozen mineral species which are essentially silicates of alumina with iron or lime, magnesia, manganese, and chromium. They crystallize in the Regular or Isometic system usually in the form of 12- and 24-faced crystals, known as the dodecahedron and the trapezohedron, with a hardness of from 6.5 to 7.5, and exhibiting a variety of color, the most common among which is some shade of red or brown. The specific gravity varies from 3.55 to 4.30. Probably the two most prominent species of garnet are almandite, the iron-alumina garnet, and grossularite, the lime-alumina garnet.
288 MINERAL RESOURCES OF VIRGINIA.
Garnet is a common mineral in many of the crystalline schists ai^^ gneisses, including those derived from sediments and from igneous rod^- It is ordinarily a subordinate constituent of these rocks although in 80X»^ cases it becomes a chief constituent.
Distribution.
Garnet is a frequent constituent of many of the various types crystalline rocks composing the Piedmont area, east of the Blue Ordinarily it is only a minor constituent of the rocks in which it is fou: and, therefore, too sparsely disseminated to have commercial value. Ho ever, when of large enough size, or uniform color, and without fractuz^-^, it is of value as a gem. Very perfect and beautiful spedmens of gam^j^^si have been collected from the pegmatite dikes in which mica has mined near Amelia court-house, in Amelia county, and near station, in Hanover county. The former area has supplied a great garnets to the trade, the particular species being the manganese-alumi: garnet, spessartite.
An analysis of the spessartite from the Amelia county area, made
C. M. Bradbury, gave:
Per cent.
SiUca (SiO,) 36.34
Alumina (A1,0.) 12.63
Iron oxide (FeO) 4.67
Manganese oxide (MnO) 44.20
Lime (CaO) 1.49
Magnesia (MgO).... 0.47
Water (HaO) trace
Total 99.70
Specific gravity 4.20
An analysis by F. W. Clarke of spessartite from the mica mines of tJ^^
same locality gave:
Per cent.
Silica (SiO,) 36.36
Alumina (AlA) 20.41
Iron oxide (FcjO.) 2.76
Iron oxide (FeO) 1.76
Manganese oxide (MnO) 38.70
Magnesia (MgO) none
Lime (CaO) 0.94
Ignition 0.27
Total 100.17
In Nelson county, about 4 miles south of Arrington, an attempt htf 1^ recently been made to mine garnet in the high and steep bluffs along ^
northeast side of Tje mer. Sererml openings huTe been made in a gametifeitras seridtic schist. The garnet is of dull red color, in wdl^ defined crystals of small bnt TariaUe siae, and distributed irregnlarly through the sdiist. It is Terr abundant in some places and rather scant in others, a fact which seeminglj indicates that the garnet is confined or limited to particular layers of the rock and not disseminated through- out all parts of it It seems doubtful whether the garnet is sufficiti:itly concentrated in the rock at this locality to be of commercial importance. As a gem mineral, garnet is described on pages 386-387.
Gramet is used chiefly as an abrasi?e in theform of a sand for sawing and grinding stone and for making sandpaper. Its inferior hardness renders it of less Tslue as an abrasiTe than corundum or emerv. It is also used eztensiTely as a gem, the use to which the Virginia garnet
has been put.
Seferenoes.
Clarke, F. W. Spessartite from Amelia County, Virginia. U. S.
Geological Survey, Bulletin No. 60, 1890, 129.
Bradbury, C. H. Garnet (yar. spessartite) from Amelia County,
Virginia. The Virginias. 1885, VI, 25.
6. TALC AHD SOAPSTOHE.
COMPOSmOH.
Talc, a hydrous silicate of magnesia, is rather a widely distributed mineral but rarely occurs in large quantities. It is characterized by extreme softness, being readily cut with a knife or scratched with the finger nail, soapy feeling and entire freedom from grit. Ordinarily it is distinctly foliated and of white, gray or greenish color.
The name soapstone (steatite an impure form of talc) is ordinarily applied to a dark bluish-gray, greenish rock composed essentially of the mineral talc. Like serpentine and talc it is a hydrous silicate of magne- sia. It is never chemically pure but usually contains varying propor- tions of the minerals mica, chlorite, amphibole (tremolite), pyroxene (enstatite), together with quartz, magnetite, pyrrhotite, and pyrite. The stone is soft enough to be readily cut with a knife and has a pronounced soapy or greasy feel, hence, the name.
290 MINERAL RESOURCES OF VIRGINIA.
OCCUUtBHCB Ajrp o&ieiH.
Talc is a secondary mineral representing the alteration product of €>tbet magnesia minerals snch as tremolite, actinolite, pyroxene, or ensta-i^i^e, and is frequently associated with talcose or chlorite schists, serpaitine^ 3.xd such basic igneous rocks as peridotite and pyroxenite.
Soapstone occurs chiefly associated with the older crystalline roola In some cases, it has been derived from an altered eruptive rock ; in otli^TS, it has probably been derived from magnesian sediments by metamorph-is^i* According to Keith, the soapstone found in Fairfax county, Virginia, '^m probably derived from the eruptive rocks peridotite and pyroxenite.
DisTBiBirnoH Ajrp localities.
Talc.
The pure form of talc has only been met with in commercial quaix"t-i^ at one point in the State, namely, near Wiehle, a station on the Rl^*^ mont branch of the Southern Railway, in Fairfax county. The mate^x^w is reported to be of a good grade of white foliated talc and is operated l:>y * private party with a reasonably good annual production.
Soapstone.
Soapstone, the impure form of talc, has on the other hand rather v^'XGe distribution in the State, being limited to the area of older crystaLXi*^^ rocks, which compose the Piedmont region, east of the Blue Ridge. X>^ posits of soapstone have been noted in the following counties : Albemarf^ Amelia, Amherst, Bedford, Buckingham, Campbell, Carroll, Fairf ^-^^ Floyd, Fluvanna, Franklin, Grayson, Henry, Louisa, Nelson, and Patricfc Many parts of the beds found in these various counties are of excell^^^ grade, and the stone has been and is being quarried in at least six of th^ above named counties. As is noted in the table of production given on page 296, the quarrj^ing of soapstone in Virginia has grown to be one of the important resources in the State, with every promise of greater expan- sion in the future.
FLUVANNA AND BUCKINGHAM COUNTIES.
In Fluvanna and Buckingham counties soapstone occurs west of the slate belt and is exposed near the mouth of Hardware creek. It ^ quarried on a small scale at this locality many years ago, strictly i<^ Ideal use as healths, jambs, and other parts about chimneys. It ^^
SILICATES. 291
also made use of further east in the southern part of Fluvanna county at Bremo.
ALBEMABLE, NELSON, CAMPBELL, BEDFORD, AND FRANKLIN COUNTIES.
In Albemarle county, a little west of Green Mountain, is a belt of soapstone associated with micaceous schists, which is traced southwest- ward through Nelson into Campbell, Bedford, and Franklin counties. The belt widens in Nelson county and is associated with some serpentine. It passes thence as a narrow belt along the western base of Buffalo Ridge, in Amherst county, crossing the James river above Lynchburg, and is exposed about 2 miles west of the city on the road leading to Bedford City, and is exposed again 2.5 miles west of New London, in Bedford county. Con- tinuing in the same direction, the stone is seen again at the meadows of Goose creek, where it has been quarried to some extent. Continuing still further westward it is exposed in several nearly parallel belts, of which the most eastern makes its appearance near Pig river in Franklin county. A second belt occurs in the same vicinity near the eastern base of Jack's Mountain; a third still further west about one mile from Bocky Mount; and a fourth yet more to the west on the eastern slope of Grassy Hill. The stone has been quarried in a small way at several places in Franklin county, near Rocky Mount, and used strictly for local purposes. Exten- sive quarrying operations are in force in the Albemarle-Nelson counties portion of the belt which is described in some detail below.
AMELIA COUNTY.
In Amelia county south of Chula and 4 miles N. 60° E. from Amelia court-house, occurs a belt of soapstone of good quality which was quarried quite extensively many years ago. A long opening was operated on the outcrop in the direction of the trend of the belt, which is N. 30° W., but is now fallen in and grown up in pine. Excepting huge boulders of the soapstone exposed in the bottom of the old opening, the rocks are entirely concealed beneath a heavy cover of decay. The width of the old opening, which probably represented the thickness of workable stone, vnll not exceed 50 feet.
A second belt of soapstone of good quality is found in Amelia county about 4.5 miles north of Jetersville, a station on the Southern Railway. The soapstone is exposed in numerous places on the north side of Flat creek in several parallel belts having a general northeast-southwest direction. Exposures of the rock along the roadside show a thinly foliated
292 MINERAL RESOUBOES OF VIROINIA.
homblendic schist, probably an altered diorite, and expoenres of diabase are found in close association with the soapstone. On the head-waters of Walnnt creek, a tributary to and on the north side of Flat creek, the soapstone has been quarried to some extent. Quarrying was begun in 1 904, and during the summer of 1906, numerous smaller openings were pat down on the belt on top of the hill several hundred yards northeast of the quarry on Walnut creek. The property, including the quarry and other openings, are controlled by a Philadelphia Company and prepara- tions were in progress during the summer of 1906 to begin quanting on an extensive scale.
LOUISA COUNTY.
A deposit of soapstone of very good quality occurs near Oakland in Louisa county. Some stone is reported to hi^ve been quarried but no systematic developments have yet been imdertidien. -'
FAIRFAX COtJNTY^V'^
• ••
*;f.
In Fairfax county, there are numei'ous degosits* of soapstone and tal- cose schists, the former of which has been pfenfid ajid quarried in a num- ber of places. They form small bodies, of-sleirticular shape in close asso- ciation with eruptive rocks, especially tb0 basic ones, and are common around the gabbro areas. According to Keith the soapstone consisting chiefly of impure talc was probably derived from pyroxenite composed of plagioclase and pyroxene. He suggests that rocks of more complex original nature are perhaps represented by the talcose schists.
The principal localities where these soapstone masses are found in Fair- fax county are: Two miles east of Annandale, which is the largest area; 1 mile east of Tenley, the next largest body ; and in the area east of FaUs Church. All of these bodies have been worked to some extent and the stone used chiefly for local purposes. Considerable developments have been made in the large body east of Annandale and much stone has been quarried and sawed. The openings and outcrops show a thickness of 50 feet of soapstone. The rock is of good quality, even-grained, and of uniform light bluish-green color, without seams and schistose plains developed in it. Blocks of desirable size can be readily quarried.
GRAYSON COUNTY.
In Grayson county, in the vicinity of Mink Bidge south of Qrant j»ost-oflfice, soapstone of good quality is reported. It is also found at other
SILICATES. 293
points in the county and preparations are being made to quarry it in one or two places.
Professor Fontaine describes a belt of soapstone found 2.5 miles south- west of the Grayson Sulphur springs near the Carroll-Grayson counties line. It is reported to be of excellent quality, uniform composition, and compact texture. No foreign hard particles are contained in it and it may be planed and sawed with ease. It has a thickness of 8 feet, is traceable for 2 miles or more, and has been used locally about the fire- places in the dwelling-houses.
CAUllOLL, FLOYD, AND PATRICK COUNTIES.
Carrey mentions a thin seam of soapstone in Carroll county, ban- ning near Greeneville and extending north 54° east within 2 miles of Hills- ville; thence through Floyd within 2 miles of the court-house. It forms large ledges in places, is soft and cJasily worked. A thin stratum of soapstone is reported by Currey dh Colonel M. D. Carter's place in Patrick county, which, on account of its refractory nature, was used for hearth- stones and other local purposes.
HENRY COUNTY.
In Henry county, near Spencer's store, quarries of soapstone were opened some years ago. The material was of excellent quality and blocks of any required dimensions were reported to have been quarried. These were sawn out and then finished by planing. They were used in the foundations of houses and for other purposes.
ALBEMARLE-NELSON COUNTIES SOAPSTONE BELT.
As described above, the Albemarle-Nelson Counties Soapstone belt lies a short distance west of Green Mountain and to the east, near and ap- proximately parallel to, Hawkins, Findley, Ball, and Appleberry moun- tains. It is distant from this western line of mountains from a quarter to a half mile, and it has a general northeast-southwest direction. It further roughly parallels the main line of the Southern Railway and is distant therefrom 3 to 5 miles. Quarries have been opened on the belt at numerous points with an extreme distance between the two end quarries on the northeast and southwest of nearly 30 miles. At many places where quarries are opened, the belt is apparently separated into several (three)
294 MINERAL RESOURCES OF VIRGINIA.
parallel members locally called "veins". The spacing between the differ- ent members or beds is quite variable with a probable extreme of from 500 to 800 feet. The deposits dip usually to the southeast in CQnfqimity with the enclosing rocks and at one point where the beds were favorable for measuring the dip was found to be 60°.
So far as thev were measurable at the surface from the more or less altered rock and quarry openings the thickness of the separate pAialiel de- posits of soapstone varies from 30 feet to 1G5 feet. A few of the quarries are opened at the point of greatest thickness of stone but the entire thick- ness is not worked. The ratio of worked stone to the total thickneBS at several localities varices as follows: Total thickness 120 feet, working thick- ness 100 feet; total thickness 150 feet, working thickness 75 feet; total thickness 125 feet, working thickness 65 feet. The above figaree do not indicate that of the total thickness, only the width of the present work- ings represents the total workable stone, but that the present conditions do not warrant the working of a greater thickness.
The stone varies from light bluish-gray to darker greenish-gray and from very soft to a hardness greater than that of scratching with the thumb nail. It is not penetrated by seams and the jointing is usually siifliciently far spacn^d to admit of any size blocks l)eing readily quarried. It is compact, of fine texture, and uniform, both in texture and color. A sj)rinkling of jiyrito occurs in places but it is rarely in sufficient amount to be liarmfiil to the stone. The stone is of excellent grade and is adraira- blv suited for the various uses made of it.
The enclosing or associated country-rock is a variable crystalline schist. In mineral composition variation is from a typical mica-quartz schist of thin and irregular foliation to a micaceous sandstone or quartzite which may he close crinkled, or may be thin, or moderately thick and straight banded, in the Albemarle portion of the belt, a black graphitic schist i=» associated with the mica-<|uartz schist on the east side of the soajwtonc^ belt, and at several points further southwestward, the association is with an altered basic eruj)tive rock.
This belt, whicli is iK'ing actively ojieratcd at the ])resent time, practi- cally composes the soai)stone industry in Virginia. .\s seen from the table of production given on ])age 296, the output in stone is large, and X'irgiTiia ranks as one of the largest soapstone-producing states. During the ^^unlmer of llH)fi. there were 8 quarries producing and beginning to produce stone in this belt. Two of tlie most extensively worked quarries have reached dejah^ of T^^o and 130 feet, respectively. The quarries operating
UINBRAL. RKSUI'KCES OF VIKOINIA.
PLATE XLIII.
Fig. 2.— View in nunpnlone quarry in Nelson county. SOAPSTONK QLARRIES IN VlRdlMIA.
|
UINBRAL BKSOURCES OF |
VIRGINIA. |
fLATH XUT. |
|
|
^- M |
M |
n^» |
^ |
|
■pSr ' 1^ |
w^^^^ |
P!*^ |
'^ |
|
'- fis- |
__J |
||
|
Jil|\ |
\1 |
||
|
\-f - |
|||
|
wy- |
H^ |
yj ,^ |
AH |
|
W^4 " |
n |
P^ |
'^a |
|
".t |
|
cSKi |
Fig. 2. — View in liie Nationol Soap.*lone Oimjmnj's quarry, XeUon pounly. ROAPSTONE QUARRIES IN VIRGINIA.
(( it It tt «
SILICATES. 296
in this belt beginning with the most southwesterly one in Nelson county are as follows:
Name County
The Piedmont Soapstone Company Nelson
The Phoenix Soapstone Company
The American Soapstone Cconpany
The National Soapstone Company
The Plumbers Soapstone Conipan^f ol America . ....
Virginia Soapstone Company .. .\ .'...'............ .
The Old Dominion Soapstonifi '.Cc^rporitjon ^ .. / .!'.... Albemarle
Albemarle Soapstone Company "
Map, plate XLII, shows the locatioiiV)f .the above quarries in the Albe- marle-Nelson counties belt. Plates XLIII, XLIV, XLV, and XLVI, show views in the various quarries located on this belt of soapstone.
The larger quarries in this belt are well equipped with all necessary modem machinery for getting out the stone. Channelling machines are used in quarrying the rock. At each quarry is located a commodious mill for sawing, dressing, rubbing and polishing the stone and other machines for grooving and drilling holes. The entire product of one or two of the plants goes into the manufacture of laundry tubs, where polishing is un- necessary and hence polishing machinery is not installed.
The excellent quality of the stone from this belt is adapted to a wide range of uses. The principal ones include laundr}^ tubs, sanitary purposes, electrical purposes, sinks, and cooking utensils. The mill of the Albemarle Soapstone Company, located 4 miles southeast of North Garden, is the most extensive in the South and it manufactures a much greater variety of products for utilization than any other. It has a very extensive stockyard where a large stock of the manufactured material is kept on hand. The product from this plant is marketed over the entire United States and in many foreign countries including Grermany, France, England, South Amer- ica, and Mexico.
Uses.
V
Soapstone is one of the most' durable of rooks> but on account of its sombre color, greasy or soapy feel and softness, it is undesirable for gen- eral structural purposes. Because of its ready workability due to softness, insolubility and heat-resisting qualities, it is suited for a considerable rMige of application. Most of the soapstone quarried at the present time is used chiefly in the manufacture of wash or laundry tubs, electric switch- boards and insulators, and laboratory sinks. It was formCTly used to some extent for the manufacture of stoves for heating purposes, and to some extent for fire brick, the well-seasoned stone being thoroughly fireproof,
29G MINERAL RESOURCES OF VIRGINIA.
but in lecent years its use for these purposes has not been so great. The waste material from the quarries or, in some cases, the entiie output^ u pulverized and used as a lubricant. The principal use made of the Vir- ginia soapstone is given above. Much of it was formerly used in the manufacture of slate pencils but very little, if any, is now Hied for this purpose.
Production.
The production of talc and soapstone in Virginia is given for the
vears 1898 to 1906 inclusive.
Quantity Value
Year Short tons $
1S98 10,059 119,480
1899 10,886 107,062
1900 9,806 116,930
1901 12,611 232,900
1902' 13,221 372,168
1903' 13,118 243,652
1904* 17,625 339,928
1906« 21,700 499,780
(*) Includes Maryland.
(') Includes North Carolina.
Seferenoes.
Merrill, George P. The Non-Metallic Minerals. New York, 1904, 204-
214.
Stones for Building and Decoration. New York, 1897, 46-63.
Pratt, J. H. Mineral Resources of the United States for 1900,
1901, 1902, 1903, 1904, and 1906. F. S. Geolog- ical Survey.
Ries, H. Economic Geology of the United States. New York,
1905, 201-203.
Rogers, W. B. A Reprint of the Geologv of the Virginias. New
York, 1884, 27, 79, 297,^ 314, 469, and 482.
6. FULLESS EARTH.
Definition and Properties.
Under the term fullers earth is included a variety of clay-like materials which have the property of absorbing greasy substances. The materials are prevailingly greenish-white or gray, olive or olive-green, or brownish in
UIN'ERAL BKSOITRCBK Of VIROINIA.
e of the Albereiie nojip«toiii- i|Uiirn SOAPSTONE QUARRIES IN VIRP.rNIA.
.1
I
t
I
I
UtNEBAL RBSOrRCE» OF VIROIN'I^
I'LATE XLVI.
|
>•" |
Ml |
|
|
m-'^A |
||
|
w^ |
^^Pl |
|
|
l^i*^^^' |
||
|
m |
■--- *3CL. |
Fig. 1. — View in a rwentlj opened Hoapatone quarry in Xelao
Fift. 2.— Limestone quarry nf the Matliiexon Alkali Workt. near Saltville. SOAPSTONK AXD LIMKSTOXK QUARRIES IN VIRGINIA.
1 .
r .
SILICATES. 297
color. They resemble clay superficially, but differ from it usually, by having lower plasticity and a higher percentage of combined water in proportion to the alumina content. Chemical analysis is usually of little value, and a practical test is necessary in order to determine its worth.
Distribution and Looldities.
Fullers earth has been reported from a number of localities in eastern or Tidewater Virginia (Coastal Plain) but as yet. it has not been investi- gated and very little is known of it in Vitgrhia: Dartonhag mentioned its occurrence in Westmoreland and Richmond counties, Virginia, and St. Mary's county in Maryland. He says:
"Eastward in the Chesapeake formation the beds of infusorial or diatomaoeous remains are often sufficiently pure for commercial use as ''fuller's earth". The largest deposits are near the base of the formation, and they are best exposed in the bluffs along the Potomac at the mouth of Pope Creek, Maryland, where at one time they were working for ship- ment. The deposits underlie the western part of Westmoreland, Richmond, and St. Mary counties and the southeastern part of Charles County, and they are exposed at many points along streams and in road-cuts. The purity of the material is diminished in some portions of the district by admixture with clay or sand, but over much of the area there are large supplies of relatively pure deposits."
Professor Rogers refers to the beds of infusorial or diatomaceous earth in the Tertiary formations around Richmond as having been regarded as a fine clay or fullers earth.
Uses.
The material was formerly used chiefly by fullers for removing grease from cloths. It is now principally used in deodorizing and clarifying fats, oils, and greases.
\ -m
Seferenoes.
Darton, N. H. Geologic Atlas of the United States. Nomini Folio
No. 23. U. S. Geological Survey, 1896.
Merrill, G. P. The Non-Metallic Minerals. New York, 1904, 248-
250.
Rogers, W. B. A Reprint of the Geology of the Virginias. New
York, 1884, 449.
298 MINERAL RESOUKCES OF VIRGINIA.
VI. NIOBATES AND TUNGSTATES.
1. GOLTTMBITE.
The mineral eolumbite^ a niobate and tantalate of iron and manganese, occurs in the mica mines of Amelia county with microlite in fine crystals, but so far as is known not in sufScient quantity to be of commercial yalne. Except as mineralogical specimens and in the preparation of the salts of columbium and tantalium the mineral has but little demand.
An analysis of the columbite from Amelia county gaye Professor Dun-
nington the following results :
Per cent.
Nb,0, 31.40
Ta,0. 53.41
SnOs trace
FeO 5.07
MnO 8.05
CaO 1.27
MgO 0.20
YA 0.82
Total 100.22
Specific gravity 6.48
2. SIPTIITE.
The mineral sipylite, the niobate of erbium chiefly with the cerium metals^ has been described by Dr. J. W. Mallett as occurring sparingly at the northwest slope of Little Friar Mountain in Amherst count}*.
An analysis of the mineral from this locality bv Professor W. G.
Brown gaye :
Per cent.
NbjO^ 48.66
WO 16
SnO, .OS
ZrOj 2.01)
ErA 27.94
Ce^O, 1.37
LhjOj 3.92
1)1,0. 4.06
UO 3.47
FeO 2.04
BeO 62
MgO 05
CaO 2.61
Na.O 16
K.O 06
H,0 3.19
MnO
LijO tr.iie
Total 100.48
NI0BATE8 AND TUNGSTATES. 299
3. WOLF&AMITE.
The mineral wolframite, a tungstate of manganese and iron, occurs in the Blue Ridge in the extreme northeastern part of Rockbridge county at Irish creek, in association with the tin ore, cassiterite. It is not known whether the mineral occurs at this point in any quantity. The principal use made of the mineral wolframite, when foimd in suflScient quantity, is for tungsten, which is utilized chiefly in the manufacture of the so- called self-hardening steel. The material is introduced either as a ferro- tungsten or as the powdered mineral.
Seferenoes.
Brown, W. Q. Analysis of A New Mineral containing Niobium from
Amherst County, Virginia. Chemical News, 1877, XXXVI, 158-159.
Occurrence of Wolframite at Irish Creek, Rockbridge County, Virginia. American Chemical Journal, VI, 185.
Dunnington, F. P. Analysis of Columbite and Monazite from Amelia
County, Virginia. American Naturalist, 1882, XVI, 611.
New Analysis of Columbite and Mcnazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611.
Columbite, Orthite, and llilonazite from Amelia County, Virginia. American Journal of Science, 1882, XXIV, 153-154; American Chemical Jour- nal, 1882-83, IV, 138-140.
Mallett, J. W. On Sipylite, A New Niobate, from Amherst Count v,
Virginia. American Journal of Science, 1877, XIV, 397-400; Ibid. 1881, XXI 1, 52.
VII. PHOSPHATES.
1. APATITE AND FHOSFHATIG MARL.
Like most of the mineral de|)osits of Virginia the phosphate deposits await investigation. So far as we have knowledge of these, three forms of phosphatic material are found, the first tyj)e of which occurs in the Coastal Plain region and inchides tlic phosphatic marls described on pages 397-399; the second in the Blue Ridge region and includes a phosphatic
300 MINERAL RESOUBOES OF YIROINIA.
rock composed of apatite and ilmenite ; the third in the Paleozoic sediments west of the Blue Bidge and includes a pebble phosphate.
The Coastal Plain phosphatic material is discussed, so far as we have knowledge of it, under Marl on pages 397-399.
HELSOHITE (PHOSPHATE BOCK).
A unique and interesting as well as extensive occurrence of phosphatic material is noted at two localities in the Blue Bidge region, namely, in Nelson and Boanoke counties. The rock is closely identical in the two localities; that occurring in Nelson county being known for many years, and has been extensively prospected on many farmfi, while that in Boanoke county has only recently been noted but actively prospected. For this type of rocks, I have elsewhere proposed the name Nelsonite, for the name of the county in which it was first found.
Nelson Connty.
The phosphate rock in Nelson coimty occurs in the foot-hills of the Blue Bidge, near Boseland, about 7 miles northwest of Arrington, a station on the Southern Bailway, and again 5 miles northeast of Boseland at Bryanfs post-office. (Map, figure 38.) It is found at a distance of from a quarter to a half mile west of Boseland on both sides of Tye river, and has been traced for a distance of 2 miles southwest of the river on the Giles place and in a northeastward direction to a point about half a mile east of Bryant, giving a total distance of about 7 miles along a northeast- southwest direction, as shown in figure 38, on page 233.
When fresh, the phosphatic material is a hard rock composed of granu- lar white apatite and black ilmenite. It has been extensively prospected near Boseland and Bryant by means of pits, open cuts, and shafts; and near Boseland by numerous additional diamond drillings. The deepest shaft is reported to be about 65 feet and the drillings were put down to a depth of 150 feet and more.
Open cuts made near Boseland and Bryant afford some information as to the mode of occurrence of the apatite-ilmenite rock. At both places, the rock exposed in the cuts shows dike-like characters in relation to the en- closing decayed gneisses and schists. As nearly as could be determined it conforms approximately to the structure of the enclosing schistose rocks with sharply defined contacts on the two sides. The greatest exposure in
PH08PHATS8.
301
the cuts, vhich was at Bryant post-office, gave a width of the apatite- ilmenite rock (Nelsonite) from wall to wall of 8 feet. (Figure 43.) Greater widths than this are shown at places on the surface by the weathered ontcrops of the phosphatic rock.
The rock is penetrated by several sets of intersecting, closely spaced joints, which break it into small blocks when struck with the hammer. The ratio of apatite to ilmenite is variable, ranging from a rock com- posed of dominant apatite to one composed of dominant ilm^te, with all intermediate gradations.
The Virginia Phosphate and Paint Company was organized some years ago for the purpose of working the rock near Boseland for the phosphate which it contains. Should some extended use be found for tiie mineral ilmenite, these deposits will be of consid^nble commercial value both for the phosphatic mineral apatite as a source of phosphoric acid and the mineral ilmenite.
Boanoke Coonty.
Abont 3 miles east of Tinton and 4 miles east of Boanoke, a similar deposit of the apatite-ilmenite rock (Nelsonite) to that described above in Nelson county, is found occurring on the Valley side aod near the base of the Blue Ridge, at an elevation of abont 1150 feet above bea-level. like the Nelson county deposit, the Roanoke county masy shows similar dike-like characters and its traceable on the outcrop in the direction of strike for some distance. It occurs near the contact of the Valley limestone of Cambro-Ordovician age and the crystalline rocks of the Blue Ridge.
Although found less than two years ago, the rock has been extensively prospected on a number of adjoiniTig farms by shafts, pits, and open cuts.
302 MINERAL RES0UBCE8 OF VIRGINIA.
for the purpose of ascertaining its valne as a source of phosphate. Speci- mens of the rock show a considerable preponderance of apatite over ihnen- ite.
PEBBLE PHOSPHATE.
Doctor R. S. Bassler, of the F. S. National Museum, noted, during some recent field studies in Virginia, the occurrence of phosphatic nodules at the base of the black shale (Romney) of Devonian age, at Clifton Forge. In a private communication to me, Dr. Bassler states that the noting of the occurrence of these phosphates at Clifton Forge was purely incidental. Thus far only the concretionar}' or conglomeratic phase of the phosphate has been noted in Virginia. Since no special search has yet been made for these phosphates in Virginia, it is not possible to predict whether commer- cial deposits of them exist or not.
An analysis of one of the phosphate pebbles from conglomerate layer at the base of Romney shale, at Clifton Forge, Virginia, gave:
Per cent.
Insoluble matter 25.26
Organic matter 32
Ferric oxide 1.21
Alumina 1.04
Lime 30.86
Magnesia 27
Phosphoric anhydride 27.62
2. DXrFBENITE.
The mineral dufrenite, an hydrous phosphate of iron, is found iii Rockbridge county where it forms radiated coarsely fibrous masses of « dark greenish brown color, forming an irregular bed of about 10 inches in depth, underlying limonite.
Analyses of the dufrenite from Rockbridge county, made by Professor J. L. Campbell and Mr. Massie, gave the following results:
Massie Campbell Per cent. Per cent.
Ferric oxide ( Fe^,) 50.89 50.86
Ferrous oxide (FeO) 6.30 6.14
Phosphoric oxide {PA) 31.06 31.76
Water (H,0) 8.35 8.63
Alumina (Al,0,) 0.25 0.21
Magnesia (MgO) 2.16 0.76
Lime (CaO) 1.12
Manganese oxide ( MnO ) 0.24 0.40
Silica (SiO,) 0.20 0.12
Total 100.05 99.89
PHOSPHATES. 303
3. STSEHOITE.
Dr. Koenig has described the mineral strengite, an hydrous ferric
phosphate, as occurring in distinct crystals in cavities in dufrenite in
Bockbridge county. He gives the following analysis of this mineral from
Bockbridge couniy, Virginia :
Per cent.
Iron oxide (Fe,0,) 42.30
Phosphoric oxide (P>0.) 39.30
Water (H,0) 19.87
Total 101.47
4. MONAZITE.
Monazite^ essentially an anhydrous phosphate of the rare earths of the cerium group containing usually a variable amount of thorium, which element gives the mineral its commercial value, has been found only in one locality in the State, namely, Amelia county. The mineral occurs at the mica mines near Amelia court-house in large coarse crystals and masses in association with microlite etc., but not in commercial quantity. Analyses of monazite from Amelia county, Virginia, gave:
Per cent. Per cent.
Phosphoric acid 24.04 26.12
Cerium oxide (Ge/),) 16.30 29.89
lanthanum oxide (LasO,) 10.30
Didimium oxide (DiA) 24.40 26.60
Yttrium and erbium oxides* 1.10
Silica (SiO,) 2.70 2.86
Thorium oxide (ThO^) 18.60 14.23
Iron oxide (FcaO,) 0.90
Alumina (AlA) 0.04
Ignition 0.67
Total 98.38 100.42
Specific gravity 5.30
The principal use made of monazite is in the manufacture of electric and incandescent lamps.
References.
Campbell, J. L. On Dufrenite from Rockbridge County, Virginia.
American Journal of Science, 1881, XXII, 65-67; The Virginias, 1881, II, 76.
On Strengite from Rockbridge County, Virginia. Proceedings Academy of Natural Sciences, Phila- delphia, VII, 277-278.
804
MINERAL RESOURCES OF VIRGINIA.
Dunnington, F. P. Analysis of Columbite and Monazitc of Amelia
County, Virginia. American Naturalist, 1882, XVI, 611.
New Analysis of Columbite and Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611.
Columbite, Orthite, and Monazite from Amelia County, Virginia. American Journal of Science, 1882, XXIV, 163-164.
Notes on the Occurrence of Ceri^ain Minerals in Amelia County, Virginia. American Journal of Science, 1883, XXV, 330-339.
Notes on Monazite from Amelia Couri>-Hou8e, Vir- ginia. Proceedings Academy of Natural Sciences, Philadelphia, 1882, XXXIV, 15-16.
Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 423-424.
Chemical News, 1880, XLII, 181.
American Journal of Science, 1882, XXIV (3. s), 260.
Fontaine, W. M.
Koenig, G. A.
Massie. Penfield, S. L.
VIM. NITRATES.
1. NITEB; POTASSITTM NITRATE.
General properties and occurrence, — Potassium nitrate, known com- mercially as niter, when pure, is white in color, subtransparent, and tastes saline, and cooling. It dissolves readily in water and deflagrates vividly on burning coals. Hardness, 2; specific gravity, 2.09 to 2.14.
The mineral usually occurs in minute needle-like crystals and as crusts on the surface of earth and rocks; and scattered in the loose soil of limestone caves and similar dry and protected places.
Distribution. — In Virginia, niter is limited to some of the numerous caves and caverns in the Shenandoah limestone of Cambro-Ordovician age, of the Valley province, on the west side of the Blue Ridge. It is found mingled with the earth in many of the caves of the Valley region and has been procured from time to time in considerable quantities from this source, although there is no actual production. As found in the Virginia caves, the niter is often of impalpable fineness and, at times, contains a considerable quantity of the lime salts.
Concerning the origin of the niter earths in the caves of the middle
SULPHATES. 305
end southern states. Professor Bogers states that the niter was chiefly derived from the overhanging and adjacent rocks and not from sedi- ment brought in to the cave by existing or former streams. This view has been confirmed by more recent study of the source of nitrates in cave earths.
References.
Hess, W. H. The Origin of Nitrates in Caves. Journal of Geology,
1900, VIII, 129.
Bogers, W. B. A Eeprint of the Geology of the Virginias, New York,
1884, 108, 763-764.
Nitrates in Cave Earth. Proceedings of the Boston Society of Natural History, 1856, V, 334.
IX. SULPHATES.
1. BABITE; HEAVY SPAB.
COKPOSITION AND PBOPBBTIES.
The sulphate of barium, known as the mineral barite or heavy spar, is, when pure, a heavy white mineral with perfect prismatic cleavage, trans- lucent to transparent, and about as hard as common calcite, from which it can be distinguished by its greater weight and its not effervescing with acid. It is found in granular, compact and earthy masses, and in single and clustered, broad and stout crystals. In nature it is rarely pure, but ifi nearly always contaminated with other substances, the most common of which, in the commercial deposits, are manganese and iron oxides, limestone, sand, and clay. It is known commercially as barytes.
HI8T0BICAL.
Barite is found and has been mined for many years in various parts of Virginia. Probably the earliest mining of this mineral in the State was in Prince William county, within 200 yards of the Fauquier county line, about 4 miles south of east from Catlett, a station on the Southern Railway. It is claimed that the mineral was mined here as early as 1845.
Developments in Campbell and Pittsylvania counties in the Piedmont region, and near Marion, in Smyth county, southwest Virginia, were be- gun since the close of the Civil War. Mining operations were begun in these two areas at about the same time, dating back about 30 years. Min- ing and milling of barite in Tazewell and Eussell counties on a commer- cial scale are more recent, and commenced about 15 years ago.
UIHERiX RBSODBOBa OF TIBQIMTA.
SULPHATES. 307
BI8TBIBIFTI0V.
Barite is found in a large number of counties in the State but the industry has been confined to only a few of them. (Map, figure 44.) The counties in which barite is found in the State, are (1) those which lie east of the Blue Bidge in the crystalline area or Piedmont province and include Bedford, Campbell, Pittsylvania, Nelson, Buckingham, Amherst, Orange, Louisa, and Prince William; and (2) those counties which lie IV est of the Blue Bidge and are in the Paleozoic sediments of the Mountain r^on and comprise Tazewell, Bussell, Bland, Wythe, Washington, Scoti, Smyth, Montgomery, Botetourt, Bockbridge, Warren, and Frederick. Of these, Bedford, Campbell, Pittsylvania, and Prince William, of the Pied- mont province; and Smyth, Tazewell, and Bussell of the Mountain province have practically yielded the entire production of the State. In 1906, operations were confined to five counties, namely, Bedford, Louisa, Pittsylvania, Bussell, and Tazewell. In Bedford and Louisa counties there was no production, the work being in the nature of development preparatory to shipping.
Geologically, the barite deposits in Yirginia are grouped into three unlike areas: (1) Those deposits in the red shale-sandstone series of Triaasic age; (2) those of the crystalline metamorphic area; and (3) those of the Mountain region, associated for the most part with the Shenan- doah limestone or its residual decay. (1) and (2) compose the Piedmont province which stretches eastward from the Blue Bidge.
OEHSSAL OCCXmBSHCB.
Barite is a frequent accompaniment of metallic ores, but as such it has not proved of any value commercially. As a rule, the deposits which have been worked for barite alone are associated with limestone as pockets or lenticular masses, and it follows the structure of the rock with which it is associated. In the Yirginia localities which have yielded commercial quantities of barite, the mineral is associated with limestones, largely in the nature of a replacement. In southwest Yirginia and elsewhere in the Mountain region, where the barite occurs in the limestone, it is often found as superficially loose lumps and nodules of irregular shapes and sizes em- bedded in residual clays derived from the decay of the limestone.
In Bedford, Campbell, and Pittsylvania counties of the crystalline area, a part of the ore has a similar occurrence in a dark manganiferous and ferruginous clay, locally known as umber, which is derived from the decay of the more or less impure calcareous rocks. At other points in Piedmont
o
08 MINERAL RESOURCES OF VIRGINIA.
Virginia, the occurrence of barite is in siliceous crystalline rocks, remote, so far as known, from calcareous masses. One of the best illustrations of such an occurrence is near Thaxton, in Bedford county, where the barite fills an irregular fracture in a coarse-textured granite. The local differ- ences in the mode of occurrence of barite in Virginia are best brought out in the description of the three geologically unlike areas below, in which deposits are found.
THE TKIASSIC ABEA.
As yet only one deposit of barite of commercial importance has been developed in the somewhat extensive areas of Triassic rodca occurring east of the Blue Bidge. About 4 miles south of east from CaUett station, in Prince William county, and within 200 yards of the Fauquier county line, barite has been mined at different times since its opemng in 1845. It was last worked in 1903 with a production of 1,500 tens of ore. The opening of this deposit probably marks the first barite mining in Virginia.
The property is developed by 3 shafts and a number of open cuts with the greatest depth reached in mining 108 feet. The grinding and preparation of the ore for market were conducted in a mill built for that purpose at the openings. This mill was afterwards burned, and in its place now stands a partly completed crushing-house, located near the main shaft, as shown in plate XLVII, figure 1.
The geological position of this deposit is within the eastern margin of the red shale-pandslone series of the Triassic area, which crosses the Potomac river west of Washington and temdnates abruptly south of Culpeper, the Virginia portion of the New York- Virginia area as defined by Russell. The rocks of the immediate barite locality consist of ferru- ginous red sandy shales and a light-colored crystalline limestone. The measured dip at numerous places west of the mine gave 10** to 15** west of northwest. Between Catlett station and the mine, the shales are pene- trated by occasional diabase dikes.
]\Iueh of the material composing the dumps at the mine is a lime- stone breccia, in which red shale fragments are cemented by an impure cr}'stalline limestone. Fractures are frequent and are filled with barite and occasionally with calcite crystals. These facts suggest that the barite deposit occupies a crushed or fractured zone in the Triassic rocks induced, probably, by faulting, although no evidence for such is apparent on the surface. The very gentle northwestward dips of the rock would preclude folding as a possible cause of the crushing. Faulting is a characteristic structure of the Virginia Triassic areas, and indeed of the same areas,
UINBRAL RESOURCES OF VIBOINIA.
PLATB XLVII.
BARITE MINE IN PRIN'CE WILLIAM COUNTY. VIItr.lNIA.
' t
, m I
i^M ' I
i
SULPHATES. 309
•
fmther north, and it seems reasonable to ascribe the brecciation in the Prince William county barite locality to faulting.
The barite is associated with both the red shales and the impure lime- stone, usually as a deposition product from solution, filling fractures in the red shales. The widest of the barite-filled fractures are reported to be 4 to 8 feet and these form th^ chief source of the minable mineral. The barite also occurs as thin tabular cleavaUe masses in the limestone. It is of good white grade, both 'finely and coarsely crystalline massive, and judging from the ore on the dumps, quite free from most of the common impurities, especially manganese. It is reliably reported that the association of ore with limestone increases* in depth.
THE PIEDIIOHT PLATSAT7 BSOION.
Barite is reported found in the following counties of the Piedmont region east of the Blue Ridge: Campbell, Bedford, Pittsylvania, Xelson, Buckingham, Amherst, Louisa, and Orange. Also it is found near Mar- shall and XJpperville in the crystalline rocks of Fauquier county, west of the Triassic area described above. Practically the total production of barite in the crystalline area has been from 3 counties, namely, Campbell, Bedford, and Pittsylvania. In these counties the ore has been mined for 30 or more years. Prospects in some of the other counties mentioned above in the crystalline area, where the mineral is known to occur, promise well, and, doubtless, further developments in the future will prove the existence of deposits of commercial importance. Exploitation of the mineral in the crystalline area should be especially directed in those localities where lenses or bands of limestone are found and indications of the mineral exist.
The Campbell-Pittsylvania Area.
Beginning in the middle -western portion of Campbell county, a few miles east of Evington, a station on the Southern Railway, and about 15 miles south of L)mchburg, a belt ol barite deposits is traced southwestward to 3 or more miles south of Sandy Level in the northwestern part of Pittsyl- vania county, a distance of about 30 miles. Numerous openings have been made at different points on the belt, many of which have been extensively worked and have produced large quantities of excellent ore. Figure 46 is a sketch map of the belt showing the various openings made. It will be observed that the belt is near the Southern Railway for its entire distance, which offers abundant facilities for shipping the ore. At every point opened, the barite is reported to have outcropped on the surface.
UINERAL BBBOnEOEB OF VIKGIMIA.
Fig. 46. — Uap ihowiiis location of the principal bftrit* mines in the Bedford- Campball-KttnlTipia countiea area. (Att^r WalwD, Tmi. A. I. H. B.)
SULPHATES. 311
The most extensively worked deposits on the belt are grouped about two centers which occupy the northeast and southwest extremities of the belt, namely, Evington in Campbell county, and Toshes and Sandy Level in Pittsylvania count)*. Operations were begun in the two counties within a short time of each other, with probably the Hewitt mine in the vicinity of Evington the first to open, which dates back to 1874. The mines in the vicinity of Toshes and Sandy Level in Pittsylvania county were opened not less than 25 years ago. and in both counties, the mines have been operated almost continuously from the beginning to the present time.
In Campbell county, the principal mines are the Hewitt, Saunders, Phillips, and Anthony grouped near together and within a few miles east and southeast of Evington. Of these the Hewitt has been the most extensively worked. It is located on the west side of Flat creek, about 2.5 miles from Evington, and about the same distance from the Saunders and Phillips mines. It was worked almost continuously from 1874 until 3 years ago, when it was abandoned on account of water. It is developed by numerous shafts and drifts with the greatest depth reached in mining about 160 feet. This is some depth below the local water-level, making it necessary to pump the water from the openings, which was trouble- some and finally led to suspension of work. At the openings the foliation of the rocks strikes N. 55** E. and dips quite steeply to the southeast. The limestone, with which the ore is associated, has a thickness of about 60 feet and is underlain by a quartzite schist on the northwest side, locally designated the foot-wall, and overlain by a thinly foliated mica-schist on the northeast side, locally called the hanging-wall. As described above, here and elsewhere in this belt, the ore occurs as irregular bodies replacing the limestone, and as irregular rounded nodules and masses in a black manganiferous and ferruginous clay, locally called umber.
The Saunders and Phillips mines are located on adjoining properties, opened on the crest of a well-defined northeast-southwest ridge on the east side of Flat creek and about 3 miles east of Evington. The develop- ments comprise shafts, pits, and tunnels, the deepest one of which does not exceed 100 feet. The first openings were made about 20 years ago. The rock associations are identical with those described at the Hewitt mine. Strike of the schist is N. 30^ E. and dip N. 60^-65^ W. About 2 miles southwest of the Saunders mine is the Anthony mine, which has produced considerable ore.
The barite area in the extreme northwest corner of Pittsylvania cotmty has been more entensively worked than that of any part of the
312
MIlfEEAL EESOUBCES OP TIBOINU.
belt It haa been developed by a large number of mines, which are grouped in two nearly parallel belta on either side of Pig riTer and just Bonth of its entrance into Boanoke river. Beginning at the northeast end of the eastemmost belt trending approximately northeast-Boathweet, it haa beoi
> Residual red claj, 10 feet.
I Umber (black mangatiiferouB and ferruginous claj) MoUini'V r barite nodulea 10 feet
I Bante massive granular and white 10 feet
le grained ThickneM >"'
Fig 46 — Generalized columnar section at the Bennett bante mine, KttgjI""'* county (After Watson Trans A I M E)
developed by the following mines which are aligned along the strike of the rock, Berger, Ramsey. Bennett, Parser, Thompson, and Drydtn ffrij*'' This belt ia three-quarters of a mile cast of Toshes, a station on the Bockj Monnt division of the Soutiiem Railway. The second or weBteramost bdt
SULPHATES. :{13
is developed by the Tom ttnghi mine 1 mile east of Sandy Level, a station 3 tmlee weet of Toshes on the Southern RaIlna^ and by the Hatcket, Mease and Davix m*ne« southnest of Sandj Level The Davis mine is the moet Bonthwe«terIy one and is 3 mtles from Sandr Level.
The Thompson mtne is reported to have been the first one opened in the area, followed h> the Parker, Berger Bennett and Ramsay, in the order named The first four of these were worked more than 25 yeairs ago and the production of hante from each mine was vry large and of
A. I. M. E.)
excellent grade. Except the Bennett, which is operating at present, they have all been idle for some years and very little could be seen at the time of my visit in September 1906. The ore from the Campbell-Pitteylvania area is shipped to the city of Lynchburg, Virginia, nearby, where it is cleaned and ground preparatory to shipping.
The mines were developed by numerous shafts and drifts and some open work. The greatest depth yet reached in mining is 120 feet, the depth of the working shaft at the Bennett viine. A description of the Bennett mine, one of the most extensively worked in the district and the only one in operation in 1896, may be taken as typical of the area.
314 MINEBAL RESOUBCES OF VIBOIKIA.
The rock succession at the Bennett mine is shown in figure 46, which represents a vertical section made of the 120-foot shaft. As shown in this figure and also in figure 47, the wall rock is a eoarse-gniiiecl, thinly foliated mica schist intersected by pegmatite dikes, composed of coarse crystallizations of feldspar and quartz. The fresh mica schist is shown in the bottom of the shaft where it is penetrated for a depth of 20 feet, the overlying rock being a black manganiferous and ferrnginoiis day, thinly foliated, and derived from a calcareous schist in composition. A similar black clay also underlies the limestone occurring between it and the fresh mica schist. The limestone, which is a white coarsely crystaUine marble and charged to a small extent with both sulphide and silicate mineralsy is 40 feet thick and occurs between the two layers of black day.
The ore, barite, is associated with both the limestone and the black clay, in part as a replacement of limestone and as inegolar ronndel masses and nodules in the over- and under-lying days. The largest concentration of ore is between the limestone and the schist and has an average thickness of about 10 feet. The contact between the barite layer and the limestone is very irregular, the ore often penetrating' far into the limestone, as sho^-n in figure 47. The lower contact be- tween the barite and the mica schist is sharply contrasted with that mad» with the limestone and is sharply defined and quite regular. The barite is massive granular, moderately coarsely crystalline, and of good white color. Five grades of the ore are made and marketed.
Oihcr Prospects. — Openings have been made and some ore mined at the following localities between the two developed areas of this l»oh: One mile northeast of Motley's station on the Yanghan place; near Hurt station on Major John L. Hurt's place; about 3 ndles aouth- wesi of Hurt's on the Hamner place; one mile west of I>^ch's station. Also 3 miles southwest of the Hetntt mine, the Maddox mine was operated about one mile southwest of Otter River station. Bante of good quality and in largo quantity was mined here, but it has not been worked in nvont years on account of water, which makes the mining too expensive.
MODE OF OCCURRENCE,
At the various openings made along the Campbell-Pittsylvania belt the ore was exposed at the surface. Two characteristic occurrences of the barite are observeii. always in association and equally as strongly emphasized in v^ne part of the btlt as in the other. The first and principal Ov\nirrenoe is in intimate association with the crystalline limestone tf irresrular lenticular bodies or rockets, which measure 100 to 200 feet or
MIXBllAli RESOl'RCBB OF VIRGIMA.
PLATE XLVIll.
Kifr 1.— The IVnnc-tt
Fig. 2.~0|«'ning fmni wliMi ;;.v|.i.uim wa-. tiiinoci, neiir siiH plant. Hiiltville. BARITK AXU tlVPSlM MINKS IN VIRIilNIA.
: li .if'
W I'
1
SULPHATES. 315
more, replacing the limestone. At the Hewitt mine, in Campbell county, some of the barite pockets were reported entirely enclosed by limestone. The ore observes the same coarsely crystalline massive structure as char- acterizes the limestone, and in several places gradation of the ore into the limestone has been observed. For the depths attained in mining imme- diately below and above the limestone is a variable thickness of a nearly black clayey mass, usually foliated and colored black from manganese oxide, derived from the decay of limestone schist. Through this black clayey mass is usually distributed in irregular fashion lumps and nodules of barite of large and small size. Occasionally barite stringers of slight thickness are formed along the foliation planes of the 6lay. Figures 46 and 47 illustrate the different occurrences described above.
ASSOCIATED BOCKS.
The principal rocks of the barite belt in Campbell and Pittsylvania counties are crystalline schists with intercalated thin beds of coarsely crystalline limestone. Of the former, two distinct types are differentiated, namely, mica and quartz schists. The immediate rocks with which the barite is associated are marked by the essential absence of feldspar. The schists are composed of mica with minimum quartz, and they otherwise bear all the ear-marks of altered sediments, without the slightest suggestion of derivation from original igneous masses. Undoubted igneous rocks of basic composition occur near Toshes depot in the vicinity of the Bennett mine. Again, an irregular biotite gneiss of granitic composition is found within three-quarters of a mile northeast of the same mine; the origin of this gneiss, whether sedimentary or igneous, has not been determined.
In the Evington portion of the belt, the underlying rock immediately in contact with the limestone masses on the northwest side is a fine-grained quartzite schist of considerable purity, and containing small brightly re- flecting scales of white mica developed mostly along the planes of schis- tosity. The rock immediately in contact with the limestone lenses on the northeast side is a variable mica schist always of fine texture and thinly foliated. Variation is from a moderately fine-grained muscovite-biotite schist at the Saunders-Phillips mines to a very fine-grained lustrous seri- cite schist at the Hewitt mine. A fine-textured mica schist, heavily charged with minute grains and crystals (octahedra) of black magnetite, forms an additional facies of the schist at the Hewitt mine. The mica schists are composed essentially of mica without feldspar.
Those mines developed on the southwest end of the belt in the vicinity
316 MINERAL RE80UBCES OF VIRGINIA.
of Toshes, Pittsylvania county, indicate an enclosure of the limestone masses by a much coarser textured biotite-muscovite schist on the two sides. Feld- spar is only recognized as a scantily developed constituent of the rock, but thin stringers of quartz are interleaved at times with the schist and small dike-like bodies of a coarse crystallization of pink feldspar and quartz fre- quently cut across the foliation of the mica schist. The kaoiinized equiv- alents of these dike-like masses are found in the same position in the residual clays derived from the schist. (Figure 46.)
Where exposed in mining this belt, the limestone is a coarsely crystal- line marble of considerable purity in places. In color it is generally white, occasionally pink, and sometimes greenish. It contains ferro- magnesian silicate minerals, especially biotite and tremolite, and is fre- quently charged with chalcopyrite and pyrite. Manganese and iron oxides are noted in places. The limestone widens and narrows alternately, fonn- ing lenticular masses with an observed maximum thickness of 60 feet, aid conforms in dip and strike to the structure of the enclosing schists de- scribed above. In composition the rock is composed essentially of calcium carbonate with small amounts of magnesium carbonate as shown in the analyses below, made by Dr. Walter B. Ellett, of specimens collected by the
writer :
I II III
Per cent. Per cent. Per cent.
Insoluble matter 1.66 0.87 1.10
Alumina ) ^34 0.30 0.96
Iron oxide {
Calcium oxide 50.04 52.60 51.00
Magnesium oxide 3.28 1.40 1.85
Calcium carbonate 89.36 93.33 91.07
Magnesium carbonate . . . 6.61 2.82 3.73
Barium sulphate 0.62 0.65 1.62
Copper sulphide trace trace 0.36
I. White crystalline limestone from Hewitt mine, Campbell county. II. Same as I.
III. White and pink crystalline limestone from Ramsay mine, Pittsylvania county.
A third important type of rock, intimately associated with the ore and whose fresh equivalent is a limestone schist, is a black manganiferous and ferruginous clay, locally called umber. It is found at every opening made on the belt and its position is next to the limestone, occurring, as a rule, on both sides. Openings made near the outcrop usually penetrate a considerable thickness of the black clay but do not as a rule encounter the limestone. When followed down, however, for a short distance in the direc- tion of the dip, the limestone appears enclosed on either side by the dark
SULPHATES. 317
clay which apparently thins on depth and ultimately disap}>ears. Like the associated schists, the hlack clay always contains the foliation planes of tlie original limy schist from which it was derived.
Leached mica folia and small partially oxidized areas of light green tremolite are fonnd in the black clay of the Pittsylvania county mines. The relations of the clay to the limestone masses and the mica schist, to- gether with its structure and composition, reasonably support the belief that it has been derived bv decav from a calcareous schist, which was transi- tional between the well-defined and differentiated limestone on the one hand, and the mica schist on the other. The kaolinized equivalents of the pegmatitic dike-like forms found cutting the schists, are observed in similar position in the black clay, as shown in figure 46. Much good ore is mined from the black clav, in which it occurs embedded as nodular masses. Figures 46 and 47 make clear the above relations of the clay to the lime- stone and schist.
Samples of the black clay collected by me from the Bennett mine in Pittsylvania county, and analyzed by Doctor Walter B. Ellett, gave the fol- lowing results :
Per cent.
IsBoluble residue 14.20
Alumina 4.96
Ferric oxide 32.40
Manganous oxide 19.49
lime 2.06
Magnesia trace
Barium oxide trace
Copper trace
ASSOCIATED MINERALS.
Calcite in the form of the coarsely crystalline marble, with which the barite occurs, is much the most abundant associate. Pyrite and chalco- pyrite are frequently present as thin stringers and as disseminated small grains and crystals in some of the ore, but more especially in the associated limestone. These are usually intermingled, and in several instances a green staining of malachite has been observed from alteration of the chalcopyrite. Manganese and iron oxides are frequent associates, but, as a rule, they are not noticeable in the best grades of the ore. These are usually more abundant and, therefore, more troublesome in the ore mined from near the surface. A small amount of the ore from the Hewitt mine, in Campbell county, is reported to have been highly charged with manganese oxide, Tremolite has been observed in both the black clav and the marble and in
ft-
places much biotito accompanies the tremolite in the limestone.
318 MINERAL RESOURCES OF VIRGINIA.
STRUCTURE.
The rocks are all schistose and preserve a general northeast strike with local variations which, so far as measured, range from N. 30** to 65 °E. Greater variations are shown in dip. The pure limestone masses are usually more or less massive, becoming decidedly schistose with de- creasing purity. In the northern end of the belt near Evington, in Gamp- bell county, at the Saunders-Phillips mines, the schists dip N. 60*'-66® W. At the Hewitt mine, which is about 2 miles S.70®W. from the Saunders, the dip is to the southeast and quite steep, affording a distinct syndinal structure as shown in figure 48. Near the southern end of the belt at Toshes, in Pittsylvania county, the openings at the Bennett mine show a variable dip to the southeast, which is much flatter than in the Campbdl
MINb
Fig. 48. — Section from Saunders manganese mine to Saunders barite mine, along a northwest-southeast course, near Evington. Length of section about 2 miles. (1) Crystalline limestone; (2) Ciystal- line schists, chiefly micaceous. (After Watson, Trans. A. I. M. E.)
county area, the probable average being about 20°. Other large mines located nearby and on the same strike as the Bennett, had been abandoned for so long a time, that no reliable measurements were possible. However, outcrops of the schist in the vicinity of the mines show dips conformable with that at the Bennett. As indicated in these measurements the folding has not been of uniform intensity throughout, but at the northeastern end of the belt folding is steeper and of a more closed type, while at the sonth- westem end it is flatter and of a more open type.
The Louisa County Area.
Barite occurrence and mining in Louisa county are limited to the Walker place, 0.76 mile south of Mechanicsville, and 3 miles south of east from Lindsay, the nearest railway point. The openings comprise a number of test-pits and several shafts, the deepest one of which is between 70 and 80 feet. Mining had been temporarily suspended for several months prior
SULPHATES. 319
to my visit and the openings were filled with water, which prevented entering them for study of the ore- and rock-relations.
The rocks are metamorphic crystalline schists of probable sedimentary origin. They are very thinly foliated micaceous schists, considerably altered, the foliation-planes of which are so regular and closely spaced as to be called, locally, slates. They strike approximately NE-SW, and observe a general southeast dip, with a probable average of about 45°. Exposures of the rock are rare because of the considerable depth of residual decay, chiefly gray and red clays. Quartz-fragments, both large and small, frequently litter the surface, indicating quartz-veins or vein-like masses interleaved with and cutting across the foliation of the schists. Careful search failed to indicate the presence of limestone and close inquiry further confirmed its absence.
Examination of the ore was necessarily confined to the dumps. The ore is a moderately white grade of coarsely crystallized barite, remarkably free from impurities other than the usual discoloration from the red iron oxide. Several lumps of the ore showed cavities filled with nearly perfect quartz crystals. Drused surfaces of large tabular barite^rystals are abundant. The ore was traced from the surface downward in the openings, observing a general but variable dip toward the southeast. It is reported to be pockety in mode of occurrence, widening and narrowing sharply and frequently, but having a thickness of about 3 feet where worked in the deep shaft.
Evidence is apparently lacking for regarding the ore as a replacement- deposit. It probably represents a filling of an irregular fracture in the crystalline schists, the bariimi salt of which was probably derived from some mineral or minerals composing the surrounding rocks.
The Bedford County Area.
Barite occurs and has been mined at a number of different points in Bedford county. Several mines near the Campbell county line yielded large quantities of the mineral. In the western part of the county, between Bedford City and Soanoke, a recent operation shows an interesting occurrence of the mineral. The deposit lies about 3 miles northwest from Thaxton, and is reported to have been first opened in 1866, when a small quantity of barite was shipped to Baltimore. It was re-opened again during tiie fall of 1906. The barite occurs in a completely schistose coarse-grained granite filling a fracture. Some distance away from the fracture the granite is entirely massive and porphyritic.
320 MINERAL RES0UBCE8 OF VIRGINIA.
As nearly as could be determined, the fracture has a N. 10** to 20° E. course, and dips about 60° southeast. An open cut about 20 feet deep has been made along the course of the fracture for a distance of about 450 feet. The granite in the vicinity of the fracture is deeply decayed, although the fracture is distinctly shown at one end of the cut where it carries no barite.
The barite is crystalline, and varies in color from white to deep blue- gray. In places, much galenite in small grains and occasional sphalerite are disseminated through the barite.
THE APPALACHIAN XOVNTAIH BEGION.
Introduction.
Barite is found in a number of counties in the middle and northern parts of the Greater Valley, but mining of it in this province has been largely confined to Russell, Smyth, and Tazewell counties in southwest Virginia. Within recent years mining operations have been limited to two of these counties, namely, Tazewell and Russell. Where found in the southwest region it is associated with either the Shenandoah limestone or its residual decay.
Oeneral Ooourrence.
In southwest Virginia, the barite of the several counties is in associa- tion with the Shenandoah limestone or its residual decay. It observes certain minor variations of occurrence from place to place. It fills in part, at least, fractures in the limestone and, in part, it replaces the limestone. In the southeastern part of Wythe county these occurrences in the limestone are fairly well shown. Here the mineral association of barite is with limonite, sphalerite, galenite, and occasional fluorite in certain openings named below, from which iron and zinc ores have beeo mined. In the Tazewell-Russell area the commoner associates are calcite and limonite, with some siderite, fluorite, and small greenish cherty masses. In addition to its occurrence in the fresh limestone the barite is found as small and large nodules irregularly distributed through the red clay, resulting from the decay of the limestone. (Figure 49.) The variation in local occurrence and in mineral association is brought out in the treat- ment of the individual areas below.
Wythe County.
In the southern part of the county, near the eastern margin of the Shenandoah limestone, barite is found in association with the metallic
8DLP HATES.
3S1
oreB in some of the zioc and iron mineB. No attention has been given to the mining of barite in this locality, nor is it known whether com- menuslly v&luable bante occnra In «cfor&l of the brown iron-ore pits at Ivanhoe, notably those of the New Itiver Mineral Company and the Painter, bante has been observed in some of the limestone chimneys (pin- nacles) as protruding irregular porous or cellular masses, intimately as- sociated at times with sphalerite and galenite These latter minerals, EolphideB, were noted in several instances as enclosures in the bante, and the bante replaces m part the limestone Northeast of Ivanhoe at the Bertha zinc mines, which have been operated for several years for iron ore, bante it found in places as loose nodules embedded in the red clav result-
Fig. 49. — Section Bbowing mode of occuirenee of barite in days derived from IfmestMie. Taiewell-RiiSHell counties area. (After Wataon, Tnuu. A. I. M. E.)
ing from the limestone decay. About a half mile northeast of Bertha at the Barren Springs iron-ore pits, barite is again found similarly occurring. The mode of occurrence and the associations of the barite in the above localities snggeet the introduction of the barium salt along fracture lines in the limestone and the partial replacement of the limestone by the barite.
Smyth County.
Barite was extensively mined some years ago near Marion, tlic county- seat of Smyth. The mining and shipping of barite in this county were begun about 1877 by Mr, Goodell, and the work was continued more or less energetically until about 1885. Some mining on a small scale has since been done from time to time.
The mining of barite in Smyth county was largely confined to the west
322 MINERAL KESOURCES OF VIRGINIA.
side aiifl at a distance of about :] miles from Marion, although some ore was mined on the east side of the town. Mining was largely confined to the lumps and nodules of barite embedded in the residual red clays derived from the Valley limestone. In some instances, mining operations extended into the fresh and hard limestone beneath the clays, but nowhere was a greater depth reached in mining than 100 feet. During the fall of 1906, 2 car-loads of barite were mined and shipped from the W. M. Copenhaver property on the west side of Marion. During the period of active opera- tions in this county the barite was chiefly milled and prepared for market in Marion. A smaller mill was operated both on the east and we!=t sides of lyfarion.
Washington County.
About 4.5 miles northwest of Glade Spring and on the north side of and about a half mile from the Saltvillo branch of the Norfolk and Western Kailway. barite occurs in the red clay derived from the Valley Umestone on the Buchanan, McNew, and White places. No prospecting nor work for barite has been done in this county.
Russell and Tazewell Counties.
Russell and Tazewell counties are the largest producers of barite, at present, in the State. Extensive deposits of the mineral are found in both counti(»s. In its geographical distribution the mineral is limited chiefly to the southern slope of Kent Ridge and its prolongatioD both northeastward and southwestward along the valley of Clinch river, extend- ing from near North Tazewell on the northeast to near Lebanon on the southwest, a distance of more than 30 miles. Map, figure 60, shows the most productive portion of the belt. Barite has been mined at numerous points along this northeast-southwest belt, the principal ones being near North Tazewell; 3 miles south of Richlands; 3 miles from Hon- aker on the Clinch river ; and on the southwestern end of the belt in the vicinity of licbanon.
The barite is found throughout this belt in the upper portion of the Knox dolomite and its residual decay. Sections AA and BB, figure o(K show the structural relations of the Knox dolomite and the adjacent rook? on the northwest and southeast," near Sword Creek and Richlands in Taze- well county. The barite occurs as small and large lumps of irregular shapes assembled in the residual clay of the limestone, and in pocket foru' and vein-like bodies filling spaces in the limestone, and in part replacmiT the limestone.
SULPHATES.
|
^§?\"i! |
iJ:^^^ |
|
§M^'%jl |
lfT\:4! |
|
?Kk -^ |
m^ |
|
j;^.jKf*| |
^2^gj_f , |
|
-B .li |
SI |
|
) v^^ |
|
|
^5~^ |
•' s)' |
|
?4"»'\, ' |
^'"H-la |
|
Cj "* 1^ |
T '''^' ? - |
|
^^kf |
\SM |
|
f\^ V|J |
K"^^ r |
|
'^S'^-^ |
^^"i; |
|
-J^ |
Ji;|j_3^-^ |
|
^\s^T'^' |
r" I |
|
iM |
|4i |
|
Cr |
fci |
|
fS^r/^ |
^V\\ £' r ^ |
->-ilUf « a***'! Ill t* :r\ \t,^rn aitflOlIJL soar •!?*
asj'x'-j^ ..•-r- t>r*»«-i»^ 1^ itiiiuij;. tun: 3«»* i**. jLFnmctft*^ i«L o" 1^^^.
M«u > ^ »»t*.t:i tu* u»r!»- Hn- ciii€f*r mlii*? an preoefOL rcr niiiTK^
Ait^Mo; i^iatl*^' t!; ' ua owrrai**' oot! cl ip- e^* an* tf*-=- -=n
'Wi'fi- (« hi. r'Miiiji-i iin/iM o' 1**511 liMiif- aiit :t- nr»>ioiiiriTtioi urd If >• •ii..-ii'' v.ii* .11;' rn\\\i\Y*K}*\v:iivi iiHim Hi* valr^' «v !iiiiei Tif*^. cmHii^-
iimu'*'Mi j/i»inu iuvMi; Miu inF**:ti*it«r»-ffi»iniiw*^rr iter, tin Tmnaniii, niif^ u«- ii; ij'^ii' .'.\»'*:t ' itii*:^^»?l ^ mil** uuir.i (r licMiurmif . ' mitts ±riTn 'Bim- <iu»« ^M .u« • '. ij'f •• ^»v iiii^ tri :ii» -oir.i'v «fvi*'T_ ail. d: tht )»*»h j_ iik
\»« ....... '"■,: '.i • '•> '#«'j-i •> i- i-r.ji uii iLi'ut "i:n i>f :•: i.'^'turiiiiir
r' ' >•-.■■ tt.-^.^"" '• ' *!< •^'>.''"..i ' M '. ■ "i- rn***^ 'jiH.. mi iL 7»c»f'tf^ -''Tu
*»1<- ■■'•,'-r' ■■•■
SULPHATES. 325
mills and are well equipped. Plate L is a view of the milling plant of the Pittsbnrg Baryta and Milling Corporation at Richlands. This plant is very commodious^ completely equipped with modem machinery, and is one of the best modem barite mills in the country.
Methods of Mining.
As noted above in the description of the barite mines, now or formerly operated in the different sections of Virginia, the mining is all surface work with no deep mining in any part of the State. The greatest depth yet reached in any of the Virginia mines is a shaft recently operated at the HJewitt mine, in Campbell county, which is 160 feet. In the crystalline area, east of the Blue Ridge, the ore is first located by surface indication and is won by vertical timbered shafts and drifts, which follow the direc- tion of the ore bodies. The machinery employed is simple, light and in- expensive. In the limestone of the southwest Virginia region the mining is shallow and largely by open pit work. In mining the ore in the fresh
limestone, blasting becomes necessary for breaking it down.
I .- ^ .. . j^.,,^ . . . -» .-^ ■.--., , PreparatioiL ..:.,/
For removal of the impurities from the better grades of merchantable ore, washing and bleaching, and occasionally jigging, are the^ only opera- tions necessary. The common impurities in the besij^kdias of ore include iron and manganese oxides, limestone, clay, and sand. Higgin^s descrip- tion in the Engineering News for 1906 of bleaching barite, in preparing it for market, is here given in full as summarized by Pratt in the Mineral Resources of the United States for 1904 :
^In bleaching the barytes, the crushed mineral is placed in wooden tanks lined with sheet lead and holding from 5 to 25 tons of mineral. The tanks used are either circular or rectangular, the former being preferable for the reason that the steaming can be more uniformly done. The best size is 4^ feet high and 8 feet in diameter. With a tank of this size, one steam inlet is required. The most satisfactory tanks are made of stout, v^ell-seasoned cypress wood, which are well braced on the outside and lined on the inside with heavy sheet lead. A lead coil of pipe one-half to 2 inches in diameter is constructed in such a manner that either steam or water 3an be supplied through the perforations which are best located at an angle of about 46** to the vertical diameter of the pipe rather than directly on top of the pipe. With the perforations in this position there is less chance of the holes becoming clogged up by fines dropping into them. In charging the tanks the barytes is added to a depth of about 3 feet and then the
330 MINKRAL KKSOL'KCES OF VlIUilMA.
ililiiti' sulphuric- acid solution, which is used as the tfolvent, is run in. Strain is admitted hy means of the coiled lead pipe, which is closed at one end ami provichMl with small perforations from G to 8 inches apart. The steam escaping from these perforations agitates and heats the mixture, wliich requires from six to eighty hours to bleach, depending entirely on the amount of iron contained in the i)arvte8. After drawing off the aci*^* the cleaned mineral is discharged either by sluicing through a specially constructed siK)ut or else ])y shovelling over the side of the tank and ^^ transferred to a wasiier in which the last traces of the acid and clav mate- rial are removed. The cleaned mineral is then dried either on large psm*^ or by means of some one of the ])atentt*d rotary driers.''
**In this bleaching process the manganese dioxide is not removed ;i u^*-^ the barytes that contains this impurity has to be ground to paste oa ^ 40-mes]i sireen and then mixed with nitrate of soda, salt, and sulpha ^k"^* acid in the proi)er proportions. This mixture is then heated in a specia. 1- ^ - constructed furnace by which process the iron and manganese are c< -^ '■-'^' verted into chlorides, which, being very soluble in water, can be complet^^^^J removed by \\a>hing. the barytes being allowed to settle in a series ^^^ tanks, generally thr(»e in number."
'*The next ste]) in the preparation of the bar3'tes for market is reduci it first to the size of fine sand by means of rolls and then to an impalpa powder by means of btdirstonc^s, after which it is ready to he packed shipment."
Uses.
'I'he priiH-ipal use made of barite at pr<»sent is as a white pigment. ^J
was formerlv used as an adulterant of white lead but it is now recogniz that barite alone makes a good pigment. At the present time, therefo barite i> put on the market as a pigment in com]K»tition with white \v- ^^ <^ and other white pigments. Tt has a permanent white color and is r"»- *^ elTected bv weather or bv gases which cause in some ea^es white lead ^ ^ blacken. According to Pratt, barite can be used to advantage in combii"^* ^' tion with either white lead or zinc white. Any pronounced increase in tr l'^ consumption of white |)igments will produce a corresponding inercajM' ^^ barite: and as barite is more and more replacing the other white pigim*!* '^^' there is a noticeable increase in the ]jroduction of barite from these cau^'«:*^• I'ratt stales that of the total production of barite, about four-fifths aro us*€»n in the manufacture of white pigment.
A further use made of barite is for giving weigiit and )>ody to cortaiD kinds of cloth and paper. The use of barite in the manufacture of bariuyw compounds for chemical purjwses is increasing.
SULPHATKS. 327
Production.
jroduction of crude barite in Virginia from 1901 to 1905 is as
Year Quantity Value
Short tons $
1901 10,270 31,260
1902 12,400 39,700
1903 5,700 20,400
1904 11,214 31,462
1905 tU68 27,838
References.
, J. L. The Steatite, Mica, Fire-clays, etc., of James river
Valley. The Virginias, 1882, III, 160.
. W. M. Notes on the Geology and Mineral Resources of the
Floyd, Virginia, Plateau. The Virginias, 1883, IV, 167, 178-180, 185-192; 1884, V, 8-12.
Edwin, Jr. Barytes and Its Pre^ar^tiou for. the Market. Engi- neering News, 1905, -LIII, 196-198; Engineering and Mining Journah 1905, tXX'IJC, 465.
Iward K. The Barytes Industry of the South. Engineering and
Mining Jourpal, 1907, LXX^g^II, 751-752.
3. P. Barite. Non-Metallic "Minerals. New York, 1904,
324-326.
H. Barvtes. Mineral Resources of the United States,
1901. 915-916.
1 • Barvtes Mining in Virginia. Engineering and Min-
ing Journal, 1905, LXXIX, 563.
Thos. L. Geology of the Virginia Barite Deposits. Transac-
iions American Institute of Mining Engineers, 1907.
ineral Resources of the United Stat(^ from 1883 to date : Mineral from 189-> to date.
2. GYPSUM.
General Properties.
lically, gypsum is a hydrous calcium sulphate correspond] ii<r to ula CaSO^.'iHoO. When pure, natural gv'psum is usually white ssive, and pearly when crystallized. It is often gray, brown, red, I black fn)ni impurities. Ordinarily the impurities are ortranic
328 MINEIIAL RE80UBCES OF VIKOINIA.
matter, ferruginous and aluminous or clayey matter, and the carbonates of lime and magnesia.
The hardness of gypsum varies from 1.5 to 2.0 ; specific gravity, 2.3. The softness of the mineral, wliich is such that it can be readily Bcratched with the finger-nail, serves to distinguish it from the other min^rak vhidi it resembles. Three principal varieties of gypsum are usually recogniaed
(1) The crystallized, foliated and transparent variety, known aa aelenite
(2) the fine fibrous and pearly or opalescent variety, known aa satin sptr and (3) the common massive, fine-granular variety, known as gypsnin. When of white color and sufficiently compact or fine-grained for carving and sculpturing, it is known as alabaster.
Origin and Occurrence.
In commercial quantities, gypsum is always associated with stratified rocks, when it is usually regarded as a chemical deposit, resulting from the evaporation of inland sea and lake waters. The gypsum beds usually occur interstratified with shales and limestones and in many places beds of rock salt. In southwest Virginia the gypsum deposits are associated with gray and purple clays in shales and shaly limestones of Lower Carboniferous (Mississippian) age. It may also be formed throa^ the oxidation of sulphides and the action of the liberated sxdphuric add <0 limestone; or through the action of solutions of metallic sulphates on calcium carbonate (limestone) ; through the hydration of anhydrite; and tlirougli the action of sulphurous vapors from volcanoes on lime-bearing rocks.
Oeneral Oeologio Relations of the Southwest Yiq;inia Sepoiits.
The gypsum and salt beds of southwest Virginia are intimately asso- ciated, and are confined to a narrow southwest-northeast valley of the North Fork of the HoLston river, extending from Plasterco on the southwest to within 3 miles west of Chatham Hill post-office on the northeast, a dis- tance of about 16 miles. Tlates XXXIII, XXXIV, and LI, views taken at Plasterco and Saltville, give a general idea of the outline and surface <?haracter of the southwest end of the valley.
The ridges knovm as Pine and Little Brushy Mountains bound the valley on the northwest sides and are composed of rocks which range in age from Silurian through Devonian to Lower Carboniferous. Near the mid- dle portion of the valley the road follows for some distance close to, on and over, thin-bedded sandstones and siliceous shales of Carboniferous age, which
HINBIUL RB80USCB8 OK VlltGIM
Fig. l.~rVie«- of the southwetit end of the Saltville vallpy i showing gypsum masses (white) mined b; the Buenu VU and Mining Company.
GYPSUM MINES AND MILL, WASHINGTON COIXTY. VIRGIN'IA.
SULPHATES. 329
form the basal slope of the ridges. These rocks, dipping at angles varying from 23** to 45** southeast, underlie the Greenbrier limestone. This lime- stone forms a narrow belt extending from and along the basal slope of the ridges to the southeast side of the river where it is cut off by a fault, which has brought up the Cambro-Ordovician limestone. - As mapped by Professor Stevenson, this fault, designated the Saltville fault, extends from the south- western end of the area, passing within a short distance to the southeast of Plasterco and Saltville, in a goieral northeast direction several miles north of Chatham Hill post-office. The rocks on the southeast side of the fault are limestones and blue limy shales which dip to the southeast at angles varying from 21** to 35**, measured along the road extending from Saltville to the limestone quarry of the Mathieson AllcaU Works, 3 miles S. 15^ E. of the Salt Works plant. A view in this quarry, showing the limestone capped by shales, is given in plate XLYI, figure 2. The accom- panying map, plate LIT, make plain the above geologic relations.
Fig. 51. — Seciioo acitMi Holctoo and Saltrille TmlleyB od a Doithwert-sootheast line midwaj between Saltville and Plaateroo. (After £. C Eckel.)
Both the gypsum and the salt deposits are limited to the narrow belt on the northwest side of the Saltville fault, included between the fault and the Carboniferous shales and sandstones of the basal slopes of Pine and Little Brushy Mountains. So far as has been made out, this narrow belc is composed of the Greenbrier limestone (Carboniferous) and the beds of g3rpsum and salt. Figure 51, a section by Eckel across the Holston and Saltville valleys, along a northwest-southeast line between Saltville and Plasterco, shows the relations of the Greenbrier limestone and the gypsum- salt beds.
Mining Developments.
Commercial deposits of gypsum in Virginia occur only in Washington and Smyth coxmties, in the narrow valley of the North Fork of Holston river described above. Professor Rogers described the occurrence of
330 MINERAL UESOrUCKS OF VIRGINIA.
gypsum in a number of the Coajital Plain counties of eastern Virginia in association with the gruensand deposits, but no developments have been made, nor is it certain that commercial gypsum is found.
Within the limits of the Ilolston and Saltville valley gypsum has been worked at numerous points. The mines and milling plant of the Buena Vista Plaster and Mining Company, situated near the southwest aid of the Valley and about 2 miles southwest of Saltville, are the most extensive. The exact date of the discovery and first working of gypsum in this valley is unknown to the writer, but it certainlv dates back as far as the early part of the nineteenth centurv. The location of the principal mines are shown on map, plate LIl. Beginning on the northeast end of the belt the principal mines are descrilx'd in order toward the southwest.
On the Buchanan place, about 3 miles west of Chatham Hill post-office, are several openings worked to a depth of less than 50 feet. Several hun- dred tons of gypsum were mined and crushed for use as land plaster.
About 8 miles north of west from Saltville a good supply of gypsum has been mined on the Hnnioi place, situated Uss than one-half mile south of the base of Little Brushy ^lountain. This mine was first opened about 15 years ago and was developed by an incline shaft and drifts which were filled with water at the time of my visit in August, 1906. As judged by the large dump j)ile at the opening the g}'psum mined was of good quality. Tt is quite similar to that mined at Plastereo and it contains very thin leaves of interlaminated gray crystals of the g}psum.
An analysis of the gypsum from the Barnes mine made by Professor M. r». Hardin gav(» :
Per cent.
Calcium sulphate 78.60
Water 20.79
Calcium carbonate 0.21
Calcium chloride trace
Magnesium chloride trace
Organic matter 0.12
Silica, alumina, etc 0.23
Total 99.95
Gypsum has been worked in the past at a number of places along the North Fork of the Holston river Ix'tween the Barnes mine and Saltville.
The most extensive one of tliese is that of the Southern Oypsum Com- pany, Incorporated, which began ])rospeeting for g}'psum in the valley o» the North Fork of the Holston river in the summer of 1906. A drill giv- ing cores 314 inches in diameter was used and a very accurate record of the
5^ .^Y._>^
, I « 5
?i t ; I 2 s A 1 5? i" •• ^'
= ft ■ ;;
I =
"" ""41?^ if s
;|— ji— o
r r
f.'
suLrnAT^>. ,^31
formations passecl through was obtainiil. After nearly a year of drilling, the Pierson Piaster llml' farm, 3.5 mile< alx>ve Salt villi*, was purclins<*<l. Under this farm, the <1 rilling of the company has alnady (iomonstraittl a very large amount of gypsum, while a considerable portion of the farm remains to be j>rospected.
The mine of the company is well opened and by July of 1907, the Southern Gypsutu Towi/iAwv, will l>e placing gypsum on the market, Tlie full capacity of the mill will be 40(» tons per day. Of this about % will be put upon the market in the form of wall plaster, the remaining t^t> ^tll be used by Portland cement mills and in the form of land plaster,
(iypsum was worknl as nn^*ntly as 1902 at Saltville, where sseveral largo openings were developed. The gypsum mined at Saltville was shipjied to Glade Spring, where a ]»art of it was used for land plaster, but most of it was used in the manufacture of Keene's cement. In Volume IV of Thr Virginias for 1883, Major Hotehkiss re]M»rts an analysis of the gy|>sum, made by Thomas .lones from the plaster hanks of i1k* Salt Works Comj^any, to be:
Per i*ent.
Lime 32.293
Sulphuric acid 46.445
Water 20.856
Magnesia .151
Iron and aluminum oxides. ... .149 Siliceous matter .070
Total !»0.964
The niin<*> of tin* Buenu Vista Plaster and Mining Conipany at IMas- terco, about '^ miles southw<*st <»f Saltville. are much tlif most extensive in the valley. Between the years 181.") and 1857 a iuiiiiImt of iK)rings were made on this pro|>erty for the puqwse of a.^certamin^ ( 1 ) the ihiekness of the gypsum, and (VM the pn'senu* of hrinr or nnk salt. The niords of 7 of these borings taken from Bulletin No. 213 of the United States Geological Survey are here given :
VtH»t.
Well A. Bored l>etween 1815 and 1820:
Red clay 0—14
Clav and plaMer 14—120
Pure plaster 160—200
Well B. Bored in 1847:
Red clay 0— 10
Clay and pla«»ter. Imlir^toin* 10 — 30
Clay and plaster (deep red ) 30— GO
Pure plaster 50— 96
Impure blue plaster 96 — 163
Hard blue slate 163—420
332 MINERAL BESOURGES OF VIRGINIA.
Well C. Bored in 1847: Feet
Red claj 0— 10
Clay and plaster, with brown rocks 10— 70
Pure plaster 70—100
Slate and plaster 100-200
Hard blue plaster 200—380
Red slate 380-480
Gray slate 480-495
Red rocks, a little salty 495-605
Well D. Bored in 1847:
Red clay 0- 10
Clay and plaster 10-62
Plaster, with a little clay 62-200
Red clay, with a little plaster 200-385
Red clay, alkali, and salt 385-387
Pure plaster 387— 6»
Well £. Bored in 1847:
Red clay 0- 10
Clay and plaster 10— 16
Impure plaster 16— 50
Pure plaster 50-102
Slate and plaster 102— 16o
Nearly all plaster 165-210
Blue slate 210-320
Blue slate and plaster 320—390
Yellow soapstone 390-445
Pure plaster 445-490
Red rock, with a little salt 490-606
Well F. Bored in 1863:
Clay 0-17
Clay and plaster 17—60
Pure plaster 50— 83
Hard black flint rock 83-90
Pure plaster 90— 96
Plaster and sulphur balls 96-105
[Record lost] 105-109
Red and yellow soapstone 109—120
Hard blue slate and red, blue, and gray rock 120—359
Yellow and blue slate 369-390
Yellow and blue slate, salty 39(M60
Wdl 6. Bored in 1864:
Sand and gravel ^ S
Blue clay 20-30
Hard white sand rock 30-40
Clay and plaster 40— ^
Buhrstone 55— 60
The present mines lie near the southeast side of the valley and are
dereloped by drifts and shafts, the deepest one of which is nearly 200
tet A depth of 280 feet was reached in one of the old shafts. The ma-
■tal •• mined ia ground and calcined at the milling plant of the company
SULPHATKS.
335
to 1906, inclusive, was kindlv furnished me bv Mr. Wvndham B. Bobertson, President of the Buena Vista Plaster and Mining Company.
Year Quantity Value
short tons $
1890 '. 6,360 20,782
1891 5,959 22,674
1892 6,991 28,207
1893 7.014 24,369
1894 8,106 24,431
1895 5.800 17,369
1896 5,955 17,264
1897 6,374 16.899
Year
Quantity short tons
1898 8,378
1899 11,480
1900 11,940
1901 15,236
1902 10,418
1903 14,741
1904 13,784
1906 16,678
1906 20.006
Value
$ 23,388 32,043 18,111 45,144
References.
Eckel, E. C. Salt and Gypsum Deposits of Southwestern Virginia.
U. S. Geological Survey, Bulletin No. 213, 1902, 406-417.
Gypsum Deposits in Virginia. U. S. Geological Sur- vey, Bulletin No. 223, 1904, 36-37.
The Saltville Fault. Proceedings American Philo- sophical Socie^, 1881, XIX, 349.
The Geology of Saltville, Virginia. The Virginias, 1881, II, 92-93.
Some Notes on the Holstein, Virginia, Salt and Gvp- sum. The Virginias, 1882, III, 20-21 ; 42.
Stevenson, John J. Notes on the Geological Structure of Tazewell, Rus- sell, Wise, Smyth and Washington Counties, Vir- ginia. Proceedings, American Philosophical So- ciety, 1884, XXII, 114-161.
The Salt and Gvpsum Deposits of the Holston, Vir- ginia, Valley. * The Virginias, 1885, VI, 53-55.
Fontaine, W. M.
Hotchkiss Jed.
Jiobertson, W.
Kogers, Wm. B.
A Beprint of the Geology of the Vir;:inias. New York, 1884.
336 MINERAL RESOURCES OF VIRGINIA.
X. HYDROCARBONS.
I. COAL AND ITS BY-PRODUCTS.
1. COAL.
HISTORICAL.
The first coal mined in the United States was in the Richmond basing where mines were opened and worked on the James river, near Richmond^ as early as 1750. For the next 71 years, or from 1750 to 1822, there are no available records of production from the mines near Richmond; the first year for which figures of production are given is 1822, when 54,000 short tons of coal were mined. In 1824 the production was 67,040 short tons; in 1826, 88,720 tons; and in 1828, 100,280 tons. The productioft from the Richmond basin continued to increase until 1832, when it began to decline. Shortly after the decline began in the Richmond basin, areafr in the nortliwestem part of the State (now West Virginia) began to pro- duce coal, and until West Virginia was made a separate state in 1863^ Virginia was numbered as one of the important coal-producing states, which rank has been restored in recent years by the mining of the large reserves of coal in the southwestern part of the State.
The construction of the Norfolk and Western Railway through south- west Virginia, in 1882, opened up the famous Pocahontas coal district^ which lies partly in Virginia and partly in West Virginia. likewise, the building of the Clinch Valley division of the Norfolk and Western Railway^ nine years later, marked the beginning of the development of the Wise county coal district. The developments in these two fields in southwest Virginia, Tazewell county in 1883, and Wise county in 1891, again restored Virginia to importance as a coal producer. Each year since, the production has shown a large increase over that of the preceding year, and out of 31 coal-producing states in 1905, Virginia ranked as fifteenth.
Coal was mined in the Montgomery-Pulaski counties area prior to ih^ Civil War, but not in an extensive way. It is reported that some of the coal used in the bunkers of the Merrimac (Virginia), in her fight with the Monitor in Hampton Roads, came from the Price Mountain mines i^ Montgomery county. For a period of 30 years after the Civil War^ the only mining carried on in this field was to supply a local market. For
COAL AND ITS BT-PHODDCTS.
338 MINERAL RESOURCES OF VIRGINIA.
a number of years past large developments have been made, more extensive and systematic mining has been carried on in accordance with modern methods, and a steady increase in output over that of the local market has been indicated yearly.
The present annual production of coal in Virginia is about 4,600,000 short tons valued at approximately $4,000,000.
DIST&IBUTIOH OF THE COAL.
The geographic distribution of coal in Virginia is shown on the accom- panying map, figure 52. As shown on this map, coal is found and has been extensively mined in two of the three larger physiographic provinces of the State, namely, the Mountain province and the Piedmont province. Of these, the deposits of the Mountain province are the only producing ones at present, although recent developments in the Piedmont province will again restore this area to the rank of a producer at an early date.
The distribution of the Virginia areas, which have pioduced or are producing coal, is as follows:
I. The Coal Deposits of the Piedmont province. Includes the Bich- mond Coal Basin, which covers parts of the following five counties: Henrico, Chesterfield, Powhatan, Goochland, and Amelia. The Farmville area, which covers parts of Prince Edward, Cumberland, and Buckingham counties.
II. Tho Coal Deposits of the Mountain province, which include a number of separate areas stretching from the northwestern corner of the State southwestward near and beyond the west side of the Great Valley.
(1) The Frederick County Area. Includes the Mountain Falls district in the southwestern portion of the county and near the West Virginia line.
(2) The Augusta County Area. Includes the North River dis- trict in the northwest corner of Augusta county and the contiguous part of Rockingham county.
(3) The Botetourt County Area. Includes the southwest corner of Botetourt county.
(4) The Montgomery-Pulaski Counties Area. Includes Price and Brush Mountains in Montgomery county, and Cloyd and Little Walker Mountains in Pulaski countv.
(5) The Bland-Wythe Counties Area. Includes a small area in the southern part of Bland county and in the northern part of Wythe county.
GOAL AND ITS BY-PHODUOTS. 339
(6) The Southwest Virginia Area. Forms the southeastern portion of the Kanawha basin, and comprises the Pocahon- tas or Flat-Top and the Big Stone Gap coal fields of the following counties: Tazewell, Russell, Scott, Buchanan, Wise, and Lee. Of these Wise and Tazewell counties are the most important producers at present.
Geologically, the distribution of the Virginia coals is not the same for all the areas enumerated above. They are comprised in two of the larger geologic time divisions: (a) The Mesozoic (Jura-Trias or Newark) coals, to which the Eichmond basin and the Farmville area coals belong; and (b) the Paleozoic (Carboniferous) coals, to which all the deposits of the Mountain province belong. Of the several coal areas enumerated above in the Mountain province, the deposits of the Mountain Falls district in Frederick county; the North Eiver area of Augusta county; the North Mountain area of Botetourt county; the Montgomery-Pulaski counties area; and the Bland-Wythe counties area, are of Lower Carboniferous (Mississippian) age. The remaining areas of this province and vastly the most important ones in the State are of Upper Carboniferous (Pennsylvanian) age.
The coals of Virginia are separately treated below by areas as grouped above.
THE PIEDMONT P&OVIHCE.
Numerous areas of Mesozoic rocks, of large and small extent, are ^stributed over the Piedmont province, east of the Blue Ridge. In a i^utnber of the Mesozoic areas, beds of coal occur, but only in one of these areas has the coal proved to be of suflScient thickness and extent to be of DiUch commercial value, namely, the Eichmond basin, near the middle eastern margin of the Piedmont region. Some coal has been mined in a sinaller, similar area in Prince Edward county, but to a very limited extent; and thin seams of coal, not of workable grade, are known in at least one other of these areas.
The Eichmond Coal Basin.
POSITION AND EXTENT OF THE BASIN.
'The Bichmond coal area, known also as the Eichmond coal basin, lies ^thin but near the eastern margin of the Piedmont plateau, on either 8ide of the James river. The total length of the area is 33 miles, and its
340 MINERAL RESOUBOES OF VIBOINIA.
maximum width is 9.5 miles, comprising a total area of about 190 square miles. It covers parts of five counties, which are Henrico, Chesterfield, Goochland, Powhatan, and Amelia. The position and limits of the basin are shown on the accompanying map, plate LIII.
This area is important, economically as well as scientifically, for it contains the only free-burning coal located immediately adjacent to tide- water in the eastern portion of the United States.
HISTORICAL.
The first coal mined in the United States is said to have been from the Eichmond basin in Virginia. In his ''Story of American Coals/* Mr. W. J. Nicolls states that coal mines were opened and worked on the James river, near Bichmond, in 1750, and for a nimiber of years not only Richmond, but Philadelphia and New York, x)btained supplies of coal from these mines. According to Parker, this antedates by 19 years the first reliable record of the use of anthracite coal in Pennsylvania. There is, however, no record of the amount. of rjOoaL^foduced prior to 1822, when, according to Taylor in his "Stckti^tics of. Pdal,"^ 54,000 short tons were mined. Records of coal production in Virginia that are available date from 1822, and the annual production from 1822 to 1906, inclusive, is given in the table on page 375.
GENERAL GEOLOGY OF THE BASIN.
The rocks bordering and underlying the Richmond basin are granites and gneisses of the mica type, and are characteristically dominant rocks ovor many parts of the Virginia Piedmont region. They are older ftan the rocks filling the basin and a marked difference in attitude and structure is shown in the rocks within and without the basin. The basin rocks are composed principally of sandstones and shales with beds of coal. The rocks are quite fossiliferous in places, both plant and animal remains occurring. The series of sedimentary rocks are penetrated by basic, igneous dikes, the whole, both sedimentary and igneous rocks, being of Newark (^fesozoic) age. Professors Shaler and Woodworth give the following table of formations of the Richmond basin rocks:
^HE NEW YOPK-
'^WBUC LIBRARY
PUBLIC LIBRARY
A8T0B. Uai»*^
THE NEW YORK
PUBUC LIBRARY
I
Aftrc#^ LENOX AND VLOLH fOOMOKVOKL.
342 MINERAL RESOURCES OF VIRGINIA.
attril)uted to the basin can probably be traced largely to the downward drag of the strata on the west side, perhaps aided by lateral pressure and folding.
The Eichmond basin rocks, in common with the Newark areas north- ward, are intersected bv dikes and sills of diabase. On the eastern border of the basin these rocks have long been known because of the association with them of natural coke in several of the coal mines. The prevailing direction of the dikes is northwest-southeast, with some trending east- west.
THE COAL BEDS OF THE BASIN.
From the published accounts of sections in the mines opened in the basin, 3 and sometimes 5 beds of coal occur, separated by beds of sand- stone and shale. The uppermost bed or seam has usually been found to be the thickest. Estimates show considerable variation in the thickness of this bed. varying from 30 and 40 feet in the old workings about Midlo- thian to 5 and 8 feet in other places. According to Professors Shaler and Woodworth, from the vicinity of Midlothian northward to Gayton (Edge Hill or Carbon Hill of the old reports) this uppermost bed is wholly or partly converted into coke, from the proximity of igneous rocks. Sir Charles Lyell states, that at Dover, on the western margin, was an upper l.('d of coal 16 feet thick, and 2 thick beds below.
The true coals of this lield are bituminous, the character of which is somewhat variable, as indicated in the analyses below. Ordinarily the quality of the coal is excellent, but occasional thin seams of calcite and pyrito have formed along the joint-planes, cutting the coal in places. In such eases the removal of the calcite and pyrite is desirable and can be easily effected by breaking and washing the coal, when an excellent fuel should be obtained. As proved by nearly a century of constant Vtse, the quality of this coal is entirely satisfactory for many purposes.
Extent of the codi bed^. — Concerning the extent of the coal beds in the Eichmond basin, I quote in full from the excellent report of Professors Shaler and Woodworth, based on a detailed geological survey of the area and published in the Nineteenth Annual Report of the United States Geological Survey for 1897-98.
"As to the area of the basin underlain by the coal beds, the evidence may be stated as follows : On the eastern margin, where the beds are best placed to be exposed in natural sections, and where they have been most extensively worked in former years, there is a fair presumption that the deposits are substantially continuous. Where, as is shown on
OOAL AND ITB BT-PE0DDCT8.
the mftp, the coal beds have not been found, as ie the case in two consid- erable Bections of the eastern border, the failure of the slight exploratione to disclose them may be fairly explained by the existence of faults which
Analyaes of coal from ike Richmond basin. South of James River.
aoviT Hill (Coie's Mlm-i.... aover Hin iCoic's MIdp).... Clover HllHCoif'sMlne)....
Btone HenRp.
Crpek Cotnjwny Hht-tl
d'rfiSd^C
Greentiol^ SI
MidlothlAD, avenwe
MldloUitiin, new Khna... Midlothian, wnvni-d.. . MWloUilan.W"'— •- Hldlothlmn...
shun. .
'e abafliScrecnod.. i.a;i Hiaiouiuvn, uveragp,.....,..^...^.„ , 1,05
HKldenhcud
EnsllRhCo.,«ld Bhafl
En«lich Co.. middle liPDCb
English, Co., lop benc;h
Cbnterfleld Mlnlna Co i.HUe i
■WUlto Pit (-*;tiiB Bhnft)
Western Outcrop
Piw
MldloUilnn.u
|
iiS |
||
|
2.»W |
||
|
Clenumn |
||
|
5.8a |
W. B. Roarn. |
North of James River.
|
Name of nt (EMlem Outcrop) |
1 ii |
M m.BO IH-dO sa'.sto ai.ai II 21.33 30.00 at! IB |
11; Ba.Ts w.ao TO.RO M.irr «5.iiO sl ftl.M |
i |
t 1 |
.\.uil>-*l |
|
17.20 10.00 S.MH 11.S2B II Him ^.80 5! 00 |
||||||
|
""""-ssiSas^v |
l'n>r. JohllHOQ |
|||||
|
«■■ n' u""'" |
||||||
|
easiii.::;;:::::::::::::;:: |
w! b! imiiTs |
bun tiirown the beds down or up, so that the shallow pits which were nmk did not pass throngh the deep surface rubble. So far as has been Icuited, there were no indications in the old workings that the coals were
S44 MINERAL RESOURCES OF YIRQINIA.
fading out in the directions of these portions or the margin where they have not yet been found. In the blank north of the Clover Rill mines the streams run so near the position of the outcrop that exploration has been discouraged by the diflSculty which would evidently be encountered from surface water.
•'On the western margin the coals are practically unknown from a point about 2 miles south of the James River, at the Old Dominion pits, to the southern extremity of the basin, though there are traces of the dark shales which are probably associated with it. In this part of the border the failure to discover the beds may well be due to the abrupt down- faulting which is known to exist along this line. At only one point, viz., in the stream bed of Turkey Branch, has it been possible to obtain a tolerably continuous section of the beds on the western margin of the field. This failed to reveal the coal-bearing beds, but there is reason to believe that they may have been thrown down by an unobserved fauH traversing a portion of the line where the strata were not disclosed, or that they are to be found under a slight cover of alluvium.
"As to the extension of the coal beds beneath the central parts of the area, the evidence in hand is insufficient to warrant a definite statement. The conditions may be briefly set forth as follows : The tolerably complete if not perfect continuity of the beds on the eastern margin and at either end of the basin appears to afford fair evidence that the coal beds have a continuous habit. It has been suggested that the coals, though continuous along the margin of the basin, may be lacking in the central parts of its area. But it should be noted that the present outcrop line is not to be regarded as the original border of the coal-bearing strata. That line was probably miles east of its present position. The existing face is, in effect, a chance north-and-south section of the deposits. There is no evident reason based on the character of this outcrop why a like exhibition of coal beds should not be had if the face were carried 1, 2, or 3 miles west- ward.
'*The failure to find the coal beds in the Sinking shaft and in the drill hole in its bottom has been considered as evidence that these beds were lacking at a point about 1 mile from its margin. This failure to :attain the coal is to be explained in the light of the information obtained in the Salisbury boring. The depth at the Sinking shaft was altogether insufficient to traverse the barren strata, the drill mjost likely not penetrat- ing to within 200 feet of the level where the coal beds might be looked for. The Salisbury drill hole, on the other hand, has shown the coal-bearing
GOAL AND ITS BY-PRODUCTS. 345
rocks at a distance of a mile from the eastern main outcrop, at a depth of about 2,350 feet below the surface.
"When all the evidence is weighed, it leads to the conclusion that the central portions of the area most likely contain coal beds in something like the measure that they are exhibited in the margin. The measure of the probability of such occurrence is rather greater as regards that portion of the field which lies to the east of a line drawn from the Clover Hill pits, near the southern end of the basin, to the Old Dominion mines, on the western margin about 2 miles south of the James Biver, than it is concerning the field west of that line. This is for the reason that out- crops have not been found along the western margin south of the Old Dominion property, though, as before noted, their failure to occur may be accounted for by accidents of faulting. Leaving out of the reckoning the southwestern portion as possibly lacking the coal-bearing beds, there re- mains an area of about 150 square miles where the deposits may reasonably be expected to occur.
"Although the information obtained from the existing and the old workings show the coal to vary greatly in thickness, and some of the beds much in quality, it is a not unreasonable estimate that the average thick- ness of the workable material is 12 feet. Allowing for occasional strips of coal which have been crushed by faulting and for loss in treatment in the breaker, the yield per acre may be roughly estimated at 1,000 tons per foot in depth, or a total of 12,000 tons. The total area which is reckoned as most probably coal-bearing (150 square miles by 640 acres) equals 96,000 acres, which, on the basis of yield above adopted, would give a total content of 1,152,000,000 tons. This reckoning, it should be said, rests altogether on probabilities
*ln none of the mines does it appear that less than two beds of workable thickness [of coal J are encountered. In other instances there is reason to believe that three, four, and at Clover Hill even five beds of economic value were found. Although all these beds thicken here and thin there and probably at points unite or separate, the coal-bearing character of the section in which they lie is probably maintained in a tolerably continuous manner."
Depth of the coal, — In regard to the question as to the depth at which the coal lies. Professors Shaler and Woodworth say: "In tho present condition of our knowledge of the basin it will be safe to assume that nt the distance of a mile from the eastern outcrop the coal-bearing section lie? ai a depth of about 2,500 feet below the surface. Farther toward the interior of the
346 MINERAL RE80UHCE8 OF VIRGINIA.
field the deptli at which it will be found will probably be somewhat greater. It is not impossible that at some points the faulting has carried these deposits more than 4,000 feet below the present surface. From what has been learned of the conditions, it seems unlikely that the section in which the coals belong is at any point as deep as 5,000 feet."
Mines.
The Richmond coal basin has been developed by numerous mines, many of which have been extensively worked with a large total production of coal. Considerable depths have been reached in some of these. Exami- nation of the map, plate LIII, shows the distribution of the mines to be along the eastern border of the basin, and along the west border in the northern part of the area in the vicinity, and north and south, of the James river. No mines have yet been opened in the more central portions of the basin. The principal mines are furi;her grouped about certain geographic centers along the border portions of the basin.
On the eastern border, beginning with the southernmost ones, the princi- pal mines are grouped about Winterpock; in the vicinity of Coalboro; Midlo- thian, including the mines of the outlying basins Blackheath, Cunliffe, etc.; to the north of and between Midlothian and the James river, the Salle and Burfoot pits; and Gay ton (Edge Hill or Carbon Hill of the old re- ports), including the outlying Deep Bun basin. In the northern portion of the basin and along the west border the principal mineis are in the vicinity of Manakin on the north and south sides of the James river; and about two miles south of west from Huguenot.
In addition to these, many smaller openings have been m^de along the border portions of the basin and drillings have been put down in places, which, in some cases, reached a depth of more than 2,000 feet.
Operations in the Bichmond basin during 1905 and 1906 were confined to Winterpock and Midlothian, in Chesterfield county, and were largely in the nature of development work preparatory to shipping. The Gayton mines north of the James river in Henrico county were closed down several years ago. Since closing down, these mines have changed hands and as yet work has not been resumed. At Winterpock a new incline was under way during the summer of 1905. At Midlothian the only mining of coal during the past two years was limited to that for the company's use. The developments at Midlothian during the past two years comprise a new in- cline 1,020 feet long by 16 feet wide and 7 feet high on a 33** pitch, to
GOAL AND ITS BY-PRODUCTS. 347
coal 8 feet thick. The coal has actually been proved in this incline tor 1,300 feet and laterally for 700 feet each way. One and a quarter miles of trackage and a tipple will be completed by the close of 1906, when the shipment of coal from this property will begin. The future prospects of this property are very encouraging. The property is under the control of the James Eiver Coal Corporation.
THE APPALACHIAN MOUHTAIN P&OVIHCE.
Lower Carboniferous (Mississippian) Goals.
The coals of Rogers' formation No. X (Vespertine) extend, as isolated areas, nearly entirely across the State, in a northeast-southwest direction, west of the Blue Ridge. So far as known the Lower Carboniferous coals in Virginia include the following fields:
(1) The Mountain Falls District in Frederick County.
(2) The North River Area in Augusta County.
(3) The North Mountain Area in Botetourt County.
(4) The Montgomery-Pulaski Counties Area.
(5) The Bland-Wythe Counties Area.
These are separately described below in the order here named.
The Monntain Falls District.
Frederick county. — Very little is known as yet in a definite way of the geology of this region. In his ''Reprint of the Virginias," page 99, Professor Sogers mentions the occurrence of coal seams in Frederick, Shenandoah, and Rockingham counties along with those of Augusta, Botetourt, and Montgomery counties. In each of these counties, with the exception of the first two, the coal-bearing horizon is known as formation No. X (Vesper- tine) or, Mississippian. The inference is, therefore, that the coal in Frederick county is of the same age.
In the first four counties, Frederick, Shenandoah, Rockingham, and Augusta, the coal is nearly identical, and according to Professor Rogers the seams vary in thickness from 3 to 7 feet. The dipping west into Little North Mountain, near Coal Run, in Rockingham county, is said to be about 4 feet thick.
Two operations have produced some coal during the past few years near Mountain Falls, in the southwestern part of Frederick county, near the We?t Virginia line. One of these was reported idle during 1905.
348
MINERAL RE80UBCE8 OF VIRGINIA.
The North Eiver Coal Field.
Augusta county. — In the northwest comer of Augusta county and the contiguous part, southwest corner, of Rockingham county is a small area of Lower Carboniferous (Mississippian) rocks which, to a limited extent, are coal-bearing near the top. The formation is mapped by Darton as the Pocono sandstone with thin coal beds and shale in the upper portion. The field is known as the North River coal field and it is west of Narrow (Little North) Mountain.
The coal is of the semi-anthracite variety and it has been mined to a limited extent in North River Gap, in Augusta county. The supply has been found sufficient for local use. The beds are thin and the coal is often crushed, but it is reported not difficult to obtain small supplies. Darton states that attempts have been made to find thicker beds by ex- cavations and deep diamond-drill borings, but without success.
Hotchkiss gives the following analyses of the coal made by Booth, Garrett and Blair of Philadelphia, from the Augusta county area:
|
Ck>n8tituent8 |
I Perct. |
II Perct |
III Perct. |
IV Perct 88.36 7.27 0.80 6.68 |
V Perct |
VI Perct |
VII Perct |
|
|
OarboD |
89.47 6.00 0.40 4.13 |
89.02 6.42 0.60 4.06 |
87.65 7.68 0.80 8.97 |
88.09 6.64 0.35 4.92 |
87.40 6.10 0.45 6.06 |
86.85 6.20 0.60 7.86 |
||
|
Volatile matter |
||||||||
|
Water |
||||||||
|
Ash |
||||||||
I and IV— Opening on Briery Branch about 100 feet above the base of Narrow Mountain. II— Little Coal Ran, from end of a 100-foot drift in an 18-lnch bed, and 6.5 miles southwest of HI- I II— Near Brler>' Branch at foot of Narrow Mountain from a drift 5 or 6 feet In a 4-foot bed. V— Half a mile southwest of II, from a bed 4 to 6 feet thick and 13 feet lower. VI and VII— From the Schcffer drift in a 6-foot bed. North River Gap, near II and V.
The North Mountain Coal Field.
Botetourt county, — The North Moimtain coal field, known by some as the Katawba, Caldwell, or Brushy Mountain field, is located along the Botetourt-Craig counties boundary, in the southwest corner of Botetourt county. I'he coal is of Lower Carboniferous age and has been used locally for a long time. The coals have had greater or less local value and were considerably mined prior to 1864 for local use. They will probably never furnish a basis for large mining enterprises, as the areas are limited, the beds are crushed and broken, and are cut by faulting.
A sample of this coal collected by Mr. 0. J. Heinrich on Stone Coal
Run, in Botetourt county, gave on analysis:
Per cent
Carbon 78.0
Volatile matter 12 2
Sulphur trace
Ash 9.8
COAI. AND ITS BY-PRODUCTS. 349
The coal is reported to be a semi-bituminous variety, averaging 12 to 14 per cent, volatile matter, 75 to 80 per cent, fixed carbon, and 5 to 9 per cent. ash. It is practically free from sulphur and burns to a white ash. According to Heinrich two principal seams were developed ; the lower about 5 feet thick with 2 feet of coal, the upper from 10 to 12 feet thick with 6 to 10 feet of coal. The seams are best developed on Stone Coal Run.
The Montgomery-Pulaski Counties Field.
Of the numerous Lower Carboniferous coal areas known in Virginia, the Montgomery-Pulaski field is much the most important one, and it is practically the only producing area at present. The area is located 30 to 50 miles west of the city of Boanoke. Map, figure 54, shows the location of the principal mines in this area.
In the Montgomery county portion of the area the mines are opened along the south slope of Brush Mountain and on the slopes of a parallel ridge locally known as Price Mountain, distant some 3 to 4 miles south from Brush Mountain. In Pulaski county developments are made on the slopes of Cloyd and Little Walker Mountains, which are a continuation southwestward of Brush Mountain in Montgomery county. The coal area lies near the northern border of the two counties and is crossed by New river, which is the dividing line between the counties.
The total estimated acreage of the Montgomery county portion of the field is about 7,000 acres. The extent of the Pulaski part of the field is not certain but it is probably nearly equal to the Montgomery field. It extends from New river to within 6 miles northwest of the town of Pulaski, which includes the developments thus far made.
Coal was mined in this field prior to the Civil War but not in an extensive way. It is reported that some of the coal used in the bunkers of the Merrimac (Virginia), in her fight with the Monitor in Hampton Roads, came from the Price Mountain mines. For a period of 30 yeai'S after the Civil War the only mining carried on in this field was to supply a local market. For a number of years past large developments have been made, more extensive and systematic mining has been carried on in accordance with modem methods, and a steady increase in output over that of the local market has been indicated yearly.
The coal seams occur in strata of Lower Carboniferous (Mississippian) age. The rock series consists of a variable thickness of sandstone, con- glomerate, and shale, dipping at angles varying from 20° to 40**. On
11
i| Ii
If
IS
p
1=
COAL AND ITS BY-PRODUCTS. 351
Price ^[ountain 5 coal seams are indicated, only one of which has yet proved to be workable. An average thickness of 4.5 foet of clean coal is mined from this seam. On Brush Mountain two seams vield workable coal which average in thickness 3 and 4.5 feet of clean coal, respectively; they are named the "Little" and "Big" seam. Likewise two seams are worked in the Pulaski portion of the field. The coal is the semi-antliracite variety of excellent quality. That from the Price ilountain mines Is harder, and consequently not so free-burning as the coal from Brush Mountain.
Of the various mines operating in the Montgomery-Pulaski fiold Ihe Merrimac mines on Price Mountain, Montgomery county, are probably the largest producers. These mines are owned by the Virginia Anthracite Coal Company and are directly on the standard-gauge steam road which connects Blacksburg with the Norfolk and Western Railway at (^anibria. A breaker (plate LIV) has recently been completed having a capacity, with the present machinery, of 500 tons per day. By installing duplicate screens and other machinery it is claimed the capacity can be more than doubled. The storage capacity of the breaker is 500 tons. The average run of the breaker at present is 100 cars of coal per month. The present depth of working at these mines is 1,026 feet on a dip of 22°.
During 1905 some half dozen operators were engaged in mining coal in the Brush Mountain area, the principal ones being the Virginia Anthracite Coal Company, the Blacksburg Mining and Manufacturing Company, and a number of private individuals.
The principal mines working in the Pulaski field during 1905 were the Altoona, Belle Hampton, and KimhalL The Kimiall mvus are located on New river, and directly on the Norfolk and Western Railway. This property has recently been acquired by the Pulasici Anthracite Coal Company, which is making extensive improvements with a promising out- look. A breaker has recently been erected at the mines, and a small one i£ being built at the Belle Hampton mine by the Belh Hampton Coal Company. A spur track connects the Belle Hampton mine with the Norfolk and Western Railway. The Altoona mines, located 6 miles northwest of Pulaski, are owned and operated by the Bertha Mineral Company at Pulaski. All the coal formerly used by the Bertha Company at its zinc furnaces in Pulaski came from the Altoona mines, but only the "firing" coal or reducing material is obtained there at present. A steam road is operated between the mines and Pulaski.
352
MINERAL RESOURCES OF VIRGINIA.
The following chemical analyses of coal, from the Montgomery- Pulaski field afford a general idea of its composition:
CoDKlituentH.
I
II
III
IV
Per cent. Per cent. Per cent., Per cent. Per cent.
Carbon 78.012
Volatile matter 11.662
Water ; 1.228
Ash ; IS.fiflO
Sulphur 0.648
75.618 11.324
0.816 11.545
0.687
70.924 12.870
0.615 15.110
0.481
72.787 12.215
0.725 18.990
0.833
70.924 12.870
0.615 15.110
0.481
VI I VII Per cent. Per cent.
74.018 9.675 1.060
14.560 0.682
80.16 13.60 0.887 5.78
Constituents.
VIII
IX
Carbon ,
Volatile matter.
Water
Ash
Sulphur
Per cent. Per cent.
79.97 9.82 0.74 8.91
X
Per cent.
|
74.24 |
72.787 |
|
11.00 |
12.215 |
|
1.16 |
0.725 |
|
18.53 |
13.990 |
|
0.388 |
XI Per cent.
74.013 9.675 f 1.080 f
14.560 ( 0.682 f
XII Per cent.
60.66 14.03
15.41
XIII Per cent.
71.86 13.14
15 00
I to V— Brush Mountain mines, Montgomery county, A. S. McCreath, analyst
VI— Prlcre Mountain mines, Montgomery county, A. S. McCreath, analvst
VII— Wilson drift. Price Mountain, Montgomery county, Dr. W. B. Ellett, analyst
VIII— Merrimac mine. Price Mountain, ^lontgoraery county, W. T. Young, analyst
IX— Klpjps mine. Price Mountain, Montgomery oountv. Dr. W. B. EHett, analyst
X and XI— William Meyers* lands, east slope of Price Mountain, Montgomery count-y*
A. S. McCreath, analyst XII and XIII— Belle Hampton mine, Pulaski county, H. U. Hill, analyst
The Bland-Wythe Counties Field.
A small coal field of Lower Carboniferous (Mississippian) or Pocooo age is found in the southern portion of Bland county and in the northerD portion of Wythe county. The coal seams appear in the Price sandstone in the vicinity of Bland court-house, Sharon Springs, and near the south- western corner of Bland county; and near and to the south of little Walker Mountain in Wythe county, on Reed creek. As a rule the seams are small and much broken by partings and the coals are generally high in the percentage of ash. The rocks are usually highly tilted and are more or less crushed.
The coals have attracted considerable attention from time to time and attempts have been made to develop them, but thus far without success.
The following analyses of the coal from the Wythe county portion of the field made by A. S. McCreath, afford some idea of its character:
Constituents.
Per cent.
Carbon
Volatile matter
Water
Ash
Sulphur
56.615 16.264
0.466 26.660
0.995
II Per cent.
59.427 17.853
0.620 20.525
1.576
I— Seven miles northwest of Wytheville from a S-foot bed. LltUe Walker Mountain, near ^ leyel of Stony creek or Reed creek. .^.f
n— Piom near the same place as I. Goal from 2-foot bed that had been exposed to the weau^ inr a month.
GOAL AND ITS BY-PRODUCTS. 353
The CarboniferouB (FennsylTanian) Coals.
LOCATION AND IMPORTANCE.
The southwest Virginia coal field is located in the extreme southwestern part of the State, on the west side of the Oreat Valley, and occupying the eastern and southeastern portions of the Cumberland plateau region in Virginia. It forms the southwestern part of the Kanawha basin, and comprises the following counties: Tazewell, Kussell, Scott, Buchanan, Wise, Dickenson, and Lee. Of these, Wise and Tazewell counties are the two most important producers at present. The other counties contain very large coal reserves which, in places, are rapidly undergoing development. The present era of railroad construction in this part of Virginia will witness, in the immediate future, extensive developments and mining of the enormous reserves of excellent coal hitherto undeveloped because of lack of railroad facilities.
The southwest Virginia coal field is vastly the largest, most productive, and most important in the State. Indeed, it is due to this field that Virginia is entitled to rank among the jjrincipal coal-producing states in the United States. It is estimated that the area of coal-bearing formations in this field comprise 1,850 square miles, with probably 80 per cent, of it productive.
The two principal coal fields in the southwest Virginia area thus far developed are (a) The Pocahontas or Flat Top Coal Field, and (b) The Big Stone Gap Coal Field. These are separately described below in the order here named.
Geologic Relations.
THE AGE OF THE COAL-BEARING ROCKS.
The coal-bearing rocks of the southwest Virginia field belong to the Coal Measures division of the Carboniferous. Probably most, if not all, of the coal-bearing rocks in this field correspond in age to the Pottsville series, the lowest subdivision of the Pennsylvania section. In the Poca- hontas or Flat Top coal field, situated in the northeastern part of the Virginia field, the Pocahontas formation of Campbell is the basal member of the series, and to the southwest in the Big Stone Gap field the Lee formation forms the basal member. The subdivision in southwest Virginia is separated by a probable thickness of coal-bearing rocks of from 2.800 to 3,000 and more feet.
354
MINERAL 11E80URCES OF VIRGINIA.
Stratigraphy.
The Carboniferous formations in southwest Virginia, as mapped in the Pocahontas, Tazewell, Bristol, and Estillville quadrangles by the U. 8. Geological Survey, are separately given below in descending order, together with the thickness and character of each formation. In these tables is given the original classification of Professor Rogers of the Virginia Car- boniferous, with the present classification of the U. S. Geological Survey.
The four quadrangles cover parts of the following counties in Virginia, which contain coal-bearing rocks: ITie Pocahontas quadrangle, inclndes a part of Tazewell county ; the Tazewell quadrangle, includes parts of Tazewell, Buchanan, and Eussell counties; the Bristol quadrangle, in- cludes parts of Russell, Wise, Scott, and Dickenson counties; and the Estillville quadrangle, includes parts of Lee, Wise, and Scott counties.
Pocahontas Quadrangle,,
RofirerN
No. XII Great congloinomU'. .
Greenbrier Bhale. No. XI I
tGreenbric»r liimistono
N<». X Montgomery ^ritn.
V. S. GeolofTlcAl Survey
Sewell formation.
Raleigh Handstom;
Ouinnimont shale ...:;:... (^lark formation ».
I'ocahontas formation...
Klucstone formation
Princeton conglomerate
Hinton formation
Rluefleld shale :.|
Greenbrier limestone ....
Prirv sandstone ,
Thidkness ''In feet
100+ 80 300 3S0
960*
800 40
1250-r»0 1250-1350
1500
200-300
Character
Handy shale
Coarse sandstone In hwivvbed* Shale, sandstone, and coal Sandstone at top: shale, santw»»'
and coal at bottom Shale, sandstone, and coal
Shale, sandstone, impupi' \W^ Coarse sandstone or oongloine'*'*' Shale and sandstone Sandstone and caknireouR shaW
Blue limestone
Shales, sandst<m(>»s and ooal f^^
No. XIII I/OWiT coal group. |
No, XII <4rt»at consloiin'mtA.'. •
r
rso. XI
Greenbrier shale
Greenbrier Ihnostonc No. X MontgonuM-y grits.
Tazewell Quadrangle.
TellowH formation '
Sequoyah formation ,
Dotson .sandNttme
Bearwallow conglonratc
Dismal formation
(Dismal conglomei*ate U'ntll)
Raleigh sandstone
Welch formation
Pocahont^iK formation....
Hiuostone formation
Princeton conglomemte
Hintr»n formation
Hluetlcld shale
( Ireenbrior limestone. Price sand.str>nc
500 450
180
60
490
0-120
100
700 380
700^800
20- 40
1160-1250
1150-1250
900-1000
a-200
Sandstone, shale and coal Stindstonc, shale and cotil
Coarse sandstone, with shiil** * , Coarse conglomemte or sand^^ Sandstone, shale, and coal
Coarse conglomerate In wc&t*?*^ ofarea . ,
Coarse sandstone, soracUine** glomeratic
Sandstone, shale, and coal
Sandstom*. shale, and rail
Shale, .sandstone, inipun* llrr»*^ Fine conglomerati* ^
Shale, sjind.stone. Impure 11»J^ Shale, impuri' limestone at ll**^
Blue llnM'iSlone Sand.st<>ne and shale
/ • >
UINERAL BESOUBCRB OF TIBQINIA.
filse Formaliaii
J^firfon tbnnatiai
GOAL AND ITS BY-PRODUCTS.
355
The Sewell formation of the Pocahontas quadrangle includes the Dot- son^ Bearwallow^ and Dismal formations of the Tazewell quadrangle. The Quinnimont and Clark formations are included in the Welch.
Bristol Quadrangle.
Rogers
U. 8. Qcologlcal Survey
No. XII Qreat <H>nK:lom€>rHt4'.
Wise formation.
GladeviUe sandstone.
Norton formation »., Lee formation...
No. XI
f Greenbrier Hliale.
Pennington Mhale . ,
I Greenbrier imeKtone. I Newman limestone.
Thickness in feet
100+ 100
1200-iaOO lfiOO+
1040-1100
1000+
E still ville Quadrangle,
f i Harlan sandstone
No. XII Great con^l(Hm'rat<*
-Vr* V T / Greenbrier nhale.
I
Wise formation.
GladeviUe sandstone ,
Norton formation.. Lee conglomerate .
Pennington shale . .. Newman limestone.
880
12fl0 120
1270 1240-1530
1040-1100
7oa-»ao
Character
Shale, sandstone, and ooal
Coarse sandstone, sometimes oon-
fflomeratic Shale, sandstone, and coal Sandstone, conglomerate, shale, coiil
Shale, (K*casional sandstone, and im- pure limestone Blue limestone
Coarse sandstone, shale, and thin c<ihI seams
Shale, sandstone, and coal
Coarse sandstone, sometimes con- glomeratic
Shale, sandstone, and ooal
Sandstone, conglomerate, shale, coal
Shale and sandstone Blue limestone
As is observed above in the tables of Carboniferous formations, the coal-bearing strata of the southwest Virginia field consist of beds of conglomerate or coarse sandstone, shale, and numerous seams of coal.
Beneath this group of coal-bearing strata and to the southeast of the Pocahontas field, in the southern portion of Bland county and the northern part of Wythe county, is a coal-bearing series of rocks, principally the Price sandstone, of Lower Carboniferous or Mississippian age. Areas be- longing to this horizon are found, as described above, at intervals along the western side of the Great Valley in Virginia as far north as Frederick county. These are described above under coals of Mississippian age.
On plate LV, are given three generalized sections from the eastern, middle, and western portions of the Big Stone Gap coal field, showing important horizons. These sections, adopted from Campbell, show four well-marked coal horizons.
MINEHAL HESOD
I
On plate LVI are given 4 8tni(
from different places in the south from tliese and from the position ( figure 52. the sfrata forming the { greatly folded rocks whioh form the diflturbance. As would naturally b more disturbance along the eaateni west. In general the beds are more exceptions gentle northwesterly dips, fignree 1, 2, 3, and 4.
In the PocalioQlas field a fault southeastern border. Traces of the found in isolated places to the eas greater eastern extension of the fieU to thicken toward the eaat.
The Big Stone Gap coal field. the coal basin, is marked hy a belt o forma the transition frOsi the neailj plateau on the west to the highly coi the east. The most pronounced Bti Powell valley aniicline, which has its Gap field. It is an unsymmetrical ant io almost vertical, while its southeas axis and gradually merges into the Middlesboro syncline, the most econ Big Stone Gap field, has sutlered con in the form of folds and flexures.
These structural features have ai development of the field.
Character <
The fuel value of a coal is di steam boiler tests, and by results i large number of analyses made of field, a few of those which seemed ones accessible to the writer are given
il
m ■ 1
r
I I
GOAL AND ITS BY-PRODUCTS.
357
Analyses of coal from the Tazewell area (Tazewell folio).
|
are |
VolaUIc Matter |
Fixed Carbon |
Ash |
Sulphur |
Total |
|
3nt |
Per cent. |
Percent. |
Per cent |
Per cent. |
Per cent. |
|
16.00 |
70.99 |
12.72 |
0.62 |
100.62 |
|
|
22.96 |
70.35 |
6.67 |
0.91 |
100.91 |
|
|
27.19 |
59.88 |
12.51 |
1.30 |
101.30 |
|
|
26.29 |
64.24 |
10.06 |
1.17 |
101.17 |
|
|
25.91 |
64.23 |
9.20 |
1.19 |
101.19 |
|
|
82.86 |
48.83 60.72 |
9.89 |
0.51 |
100.51 |
|
|
22.55 |
10.84 |
0.65 |
100.65 |
||
|
25.61 |
68.54 |
6.70 |
0.94 |
100.93 |
|
|
29.68 |
61.76 |
7.90 |
079 |
100.79 |
|
|
1 |
24.65 |
63.77 |
9.34 |
0.65 |
100.55 |
|
22.88 |
65.24 |
11.36 |
0.73 |
100.73 |
|
|
18.45 |
62.93 |
16.16 |
0.54 |
100.54 |
|
|
19.82 |
70.42 |
10.06 |
0.72 |
100.72 |
|
|
22.09 |
71.78 |
6.63 |
0.62 |
100.62 |
|
|
18.80 |
54.54 |
24.83 |
0.54 |
100.54 |
|
|
80.06 |
55.90 |
18.36 |
0.74 |
100.74 |
|
|
33.81 |
50.22 |
6.70 |
0.65 |
100.65 |
|
|
24.20 |
71.63 |
4.03 |
0.85 |
100.85 |
|
|
30.79 |
66.52 |
2.12 |
0.68 |
100.68 |
tCreath reports^ as an average of eight samples taken by himself the Pocahontas, No. Ill seam, in the Pocahontas field, the results in column I below. Cohimn II is an analysis of the same coal from the West mine of the Pocahontas Collieries Company, at Poca- , made by Professor Hite of the West Virginia Geological Survey.
ConHtltuentK
Moisture
Volatile matter Fixed carbon. .
Ash
Sulphur
Phosphorus
II Per cent,
.21
19.62
76.61
3.56
1.69
.006
naiyses of coal from the Big Stone Gap field (EstUlvUle folio).
|
Water Per cent. |
Volatile Matter Per cent. |
Fixed Carbon I*er cent. |
Sulphur Per cent. |
Ash Per cent. |
Total Per cent. |
Chemist |
|
|
1.716 |
43.069 |
48.252 |
0.738 |
6.225 |
100.00 |
McCreath |
|
|
2.234 |
35.671 |
58.016 |
0.749 |
3.430 |
100.00 |
McCreath |
|
|
2.260 |
37.270 |
57.661 |
0.539 |
2.270 |
100.00 |
Mc(*reath |
|
|
1.508 |
38.602 |
48.:«3 |
3.077 |
8.420 |
100.00 |
McCreath |
|
|
1.206 |
41.589 |
48.274 |
3.527 |
5.460 |
100.00 |
McCreath |
|
|
1.154 |
35.346 |
60.107 |
0.643 |
2.760 |
100.06 |
Mci .'reath |
|
|
0.924 |
35.971 |
5«.4;i6 |
0.579 |
4.090 |
100.00 |
McCreath |
|
|
, |
1.400 |
33.660 |
58.365 |
0.705 |
5.870 |
100.00 |
McCreath |
|
1.4frl |
36.266 |
59.741 |
0.799 |
1.730 |
100.00 |
McCreath |
|
|
2.008 |
31.4.37 |
57.704 |
0.651 |
8.200 |
100.00 |
McCreath |
|
|
1.096 |
34.684 |
58. 14;^ |
0.662 |
6.415 |
100.00 |
McCreath |
|
|
0.600 |
36.795 |
57.428 |
0.652 |
6.525 |
100.00 |
McCreath |
|
|
1.480 |
31.97 |
62.85 |
0.68 |
3.70 |
100.68 |
Potter |
|
|
2.02 |
32.18 |
60.66 |
0.90 |
5.14 |
100.90 |
Potter |
|
|
2.22 |
29.56 |
59.66 |
8.56 |
100.00 |
Potter |
||
|
r |
1.090 |
34.145 |
69.879 |
1.081 |
3.806 |
100.00 |
McCreath |
|
I |
0.840 |
a3.720 1 |
60.006 |
0.709 |
4.725 |
100.00 |
McCreath |
|
I |
0.798 |
34.022 j |
61.411 |
0.619 |
3.150 |
100.00 |
McCreath |
358 HINEKAL RESOURCES OP VIRGINIA.
The name, atratigraphic position, and location of the seame yielding the analyses given on preceding page ftre appended below in tabular form. The numbers in the first column on the left of the two tables are the same:
|
». |
».™.,*,„ |
LocaUoD |
|
|
I |
PrHuhfr creek |
||
|
fBiToll opening, on Jimw Halley opening, on Jan«B |
|||
|
V |
Under GlHdeTHlemiidHtone (•) |
||
|
VI |
Imbodcn |
||
|
M» Riat above Lae roniilotueMip |
|||
|
Lower Kanner |
TlJTiui crwk, 4 mlleii narth- |
||
|
XVI |
Lower BaiUFr . |
mp ftfetitojve Lt* conglonieTOtr |
|
|
Kennedy |
Old (Ire^Tio-Bodtne mloe. |
||
|
Kennedy |
Itenmr.a miles B. of T<u»ma |
JfcCreath and d'Inviliiers in their report entitled "Mineral Resources of the Upper Cumberland Valley. Southeastern Kentucky and South- weslern Virginia," give the following analyses of coal collected by them from the Crab Orchard district in Virginia ;
Analyses of root fro
', Crab Orchard distri and d' Invillicrs.)
Virc/inin (McCreaih
|
_ |
Wttler |
Voliillle |
|.lx>.d |
Sulphur |
Ash |
|
|
■ |
VtiT .■etil. |
Pit wnl. |
PPrcenL |
|||
|
BlgCrahOn-lmrd iTeek, Mi-ronnellopenln« BlgCmbUnliard crevk. WIlBonopenrnii |
ortS |
|||||
|
KS?BSi,f*?r«s?sir |
||||||
|
a.m |
-■n.Mi |
se.sw |
..w* |
* |
150 |
^^^ ■tj".
• '
.* -
r
t ■•
i ,
COAL AND ITS BY-PRODUCTS. 369
The Pocahontas or Flat-Top Coal Field.
INTKODUOTOBY STATEMENT.
The construction of the Norfolk and Western Eailway in 1882 opened up the famous Pocahontas coal district, which comprises Tazewell JEind Buchanan counties, in Virginia, and McDowell, Wyoming, and Mercer counties, in West Virginia. The district includes about 450 square miles of rough mountain land. The first mine is reported to have been opened in 1882, at the village of Pocahontas, Tazewell county, Virginia, from which the area derived its name. As described below, there are a number of workable seams of coal in the district, but the principal one worked at present is the great Pocahontas vein. No. Ill, which is 11 feet, 3 inches thick.
The superior quality of the Pocahonti^ coal has long established it as the best steam coal in the world.. * As such it has foremost rank, and it is used on the ocean steamers o^ the principal nations. It produces an excellent coke, but, as a rule, theilump coal is placed directly upon the market for general purposes, while the slack and fine coal go direct to the ovens for coking.
The general purity of the Pocahontas coals is remarkable; picked samples frequently run less than 1 per cent, of ash. These coals possess in an eminent degree three qualities of marked recognition: (1) Superior steaming qualities; (2) relatively smokeless qualities; and (3) superior coking qualities.
OPERATIONS.
The largest operations in the Pocahontas field are controlled by the Pocahontas Collieries Company. This company is opening up a new mine at Boissevain, which, after completion, will be followed by other new de- velopment work. In the latter part of 1906, 4 mines were operating at Pocahontas, producing from 4,000 to 6,000 tons of coal per day. One of these, the West mine, has the reputation of being the largest bituminous coal mine in the world. The coal worked here is the Pocahontas, No. Ill seam, which is 10 feet thick and unusually clean, with practically no partings and an excellent top. (See plate LVII.) The Pocahontas Com- pany is engaged in opening up its new plant at Boissevain, 3 miles west of Pocahontas. Two other plants, located 3 miles west of Boissevain, are leported will open up in the near future. Each operation is expected to produce from 3,000 to 4,000 tons of coal per day. These new mines are
360 MINEKAL RESOURCES OF VIRGINIA.
located in tlie valley of Laurel creek and will be reached by a new railiotd now under construction from Pocahontas westward.
In addition to the Pocahontas Collieries Company, the other opentort in the Pocahontas field are: tJ, 8, Browning, the Town HUl Coal Oowh pany, the Domestic Coal Company, and the Coal Creek Coal Comfomg.
THE COAL.
Introdruiion. — In the Pocahontas or Flat-Top coal field, coal has beea found in each of tlie horizons of the Carboniferous above the Blaeatone for* mation, excepting the Raleigh sandstone and the Bearwallow coTigJiMnflfli^ which attain thicknesses of 100 and 60 feet, respectively. In the TmiaJI. quadrangle, covering parts of Tazewell and Buchanan eountiea in Viiig^di^ the coal-bearing formations are 6 in number, including in ascending bite the Pocahontas, Welch, Dismal, Dotson, Sequoyah, and Tellowa f6niiaboill» In the adjacent Pocahontas quadrangle on the east the coal-bearing horaaBi include the Pocahontas, Clark, Quinnimont^ and Sewell fonnatiQiiia. Hot all the coals of the upper formations are within the Virginia poitioa rf the field, but so far as known they are represented across the line in Wflit Virginia.
A largo number of coal-beds are found within the total Teitieal linib of these formations. Some of these are thin, but at least 6 workable boAl liave l)een opened in places. Not all of these are workable^ howerer, it any one point, and in places only 1 is worked.
The coals may be conveniently described by formations, which are at follows, beginning with the oldest: (1) Coals of the Pocahontas forma- tion; (2) coals of the Welch (Clark and Quinnimont of the Pocahontas quadrangle) formation: (3) coals of the Dismal (Sewell in part of the Pocahontas quadrangle) formation; (4) coals of the Sequoyah formaiioQ; and (5) coals of the Tellowa formation.
The geological section for Tazewell and eastern Buchanan oountiei^ Virginia, and western McDowell county. West Virginia, as compiled by
Stevenson froiu Campbell's studies, is as follows:
*
362 MINEBAL RESOURCES OF VIBGINIA.
The relations of the lower beds in northeastern Tazewell county are
shown in the following section reported by McCreath :
Feet. Inches
1. Concealed measures 40 0
2. Coal 7 2 0
3. Ck)iicealed 20 0
4. Coal 6 1 6
6. Concealed 80 0
6. Coal 5 and dirt 4 6
7. Concealed 91 0
8. Coal 4 2 0
9. Concealed 90 0
10. Sandy fireclay fi 0
11. Coal S, Pocahontas 11 3
12. Fireclay 0 0
13. Shales and sMnd«tone 61 0
14. Coal 2 and shale 4 0
16. Concealed 12 i
16. Gray sandstone 16 4
17. Coal 1 1 0
18. Sandstone, some shale 67 1^
19. Sandstone, coal streaks 8 ^
20. Shale and sandstone 294 9
Coals of the Pocahontas formation, — This formation, which averages probably 360 feet in thickness, carries several beds of coal, the most im- portant one of which, in this and in succeeding formations, is the gr^t Pocahontas, No. Ill seam. The lowest seam in this formation is partially exposed near the mouth of Vail creek just across the line in West Vir- ginia, showing in that part of the seam exposed a thickness of 2 feet 8 inches. Sixty feet below the Pocahontas, No. Ill seam is a second seam which measures from 2 feet 6 inches to 3 feet 8 inches in thickness, as exposed along Tug river and Adkins branch in West Virginia.
The most important seam of the area and the one which has been developed to the greatest extent is the Pocahontas or No. Ill seam. 1^ shows a general dip to the northwest, which is irr^ular, varying from 100 feet in 3 or 4 miles in some places to as much as 200 feet in 1 mile- There are developed in the seam, in addition to the general dip, numerous gentle undulations. It varies in thickness from 4 to 10 feet, and attains its maximum thickness at the original place of opening on Coal Creek, at Pocahontas. According to Campbell it diminished in thickness from this point in all directions, but most rapidly toward the northeast. The Flat- Top Coal Land Association gives the following measurements of the Poca- hontas seam at various places: at tlie mouth of Harmon branch, 8 feet; 1 mile below, 8 feet 7 inches; at Tug River post-oflBce, 9 feet; and at each of four openings on Sand Lick creek, 8 feet. These measurements aro all in West Virginia.
GOAL AND ITS BY-PBODUCTS. 363
Near the point on Long Branch in West Virginia, where the seam passes beneath the water level, the thickness of the seam is reported to be 10 feet 11 inches. On Big creek in the vicinity of Squirejim, the thickness is 4 feet 6 inches; and at the mouth of Cucumber creek it is 6 feet 3 inches. Campbell reports the seam exposed at water level 1^4 niiles above the mouth of Big creek on Jacob Fork, but it rises rapidly above water level, from this point southward until at Cucumber creek it is 180 feet above water level. Again on Dry Fork, 1^ miles below the mouth of Keewee creek, the seam rises above water level, exposing a thickness of 3 feet 8 inches. Near the mouth of Vail creek its thickness increases to 4 feet 7 inches. Nearly opposite Sayersville on Beech creek the seam (probably Pocahontas) has a thickness of 6 feet 3 inches. Higher up on the same creek an opening exposes a thickness of 4 feet 9 inches. West of this point the seam is reported to be below water level, unless it is exposed, as suggested by Campbell, in the upturned rocks along the edge of the basin.
Coals of the Welch (Clark and Quinnimont) formation, — ^The Welch formation carries a greater number of workable coal beds than any other in the area. At Horsepen, north of Tazewell, several large seams occur which range in position from 250 to 440 feet above the Pocahontas or No. Ill seam. The seams contained within this interval of 290 feet have been grouped and named by Campbell the Horsepen group. There are 4 principal seams in the formation, the lowest one of which, the Lower Horsepen seam, is 150 feet above the Pocahontas or No. Ill seam. Back of the Bchoolhouse at Horsepen this seam has a thickness of 4 feet 9 inches. The seam is best developed above Richlands where it has been opened up, but it is extremely variable. West of Big creek the downward pitch of the anticline carries the seam below water level.
One of the best seams of this group is found 120 feet above the Lower Horsepen seam or 270 feet above the Pocahontas, No. Ill seam. Camp- bell calls it the War creek coal, where it is well shown on War creek and in the vicinity of Perryville, West Virginia. It is reported opened at 7 or 8 places on War creek and Dry Fork on the West Virginia side, and it holds a constant thickness of from 4 feet 4 inches to 5 feet.
The Middle Horsepen seam is 239 feet above the Lower Horsepen seam and 110 feet above the War creek seam. It shows 4 feet of clear coal at Horsepen. It is found 2.5 miles above Harman, on the eastern fork of the creek, and it is 130 feet above water level. It has been opened above Rich- lands on Big creek but wa5 afterwards found to be too thin for working. Campbell states that it passes below water level before reaching Coal croc^k.
364 MINERAL RESOURCES OF VIRGINIA.
At Horsepen is a heavy scam 60 feet above the Middle Horsepen or last described seam^ called the Upper Horsepen seam^ having a thicknesB of 8 feet. Four miles east of Horsepen at Smith Store this seam is 9 feet thick. It has been opened at a number of places on Indian creek show- ing a thickness of from 4 to 6 feet. It grows thinner toward the north and at Pcrryville, West Virginia, it has a reported thicJmeM of about only 2 feet, and further to the northeast at Welch the thicknefis is given as 20.5 inches.
About 100 feet above the Upper Horsepen seam is atill another seam, which 2 miles south of Bearwallow shows 2 feet of clear coaL Campbell reports 2 probable additional coals above the last mentioned seam, but their occurrence, extent and thickness are somewhat uncertain.
Coals of the Du^mal formation, — The coal which appears over a consid- erable part of the area in the Dismal formation, according to Campbell, is probably not a continuous seam but a general horizon, in which the seams vary slightly in their stratigraphic position. This coal horizon reaches its groattst development on Dismal creek, where it is reported to range in thickness from 10 to 14 feet. At the head of Dismal creek and near the Bearwallow trian^ilation station, the seam has a thicknesa of 4 feet 6 inches. It is reported to have its greatest development 6 miles above McNiel's Store. It shows again at a number of places south of Sandy Ridge; on Big Town Hill creek, near its mouth; near the sharp bend in Middle creek ; and on I^aurel creek, where it varies in thickness from 4 to 5 feet.
According to Campbell, a coal seam in the lower portion of the Dismal conglomerate has been opened in the ridge between Big Town Hill and Miul Lick creeks, showing a thickness of 3 feet 5 inches; and again on the ridge between Indian and ^fiddle creeks its thickness is 4 feet.
Coals in the Seqxwyah and Tellowa formations. — Coal seams appear in both of these formations. Those in the Sequoyah formation are not known to be of great commercial value. Those of the Tellowa formation occur beyond Virginia on Tug river in West Virginia.
The Big Stone Gap Coal Field.
LOCATION AND IMPORTANCE.
The Big Stone Gap coal field is located in southwestern Virginia and southeastern Kentucky. In Virginia it embraces parts of Wise, Lee, and Scott counties, and in Kentucky, parts of Harlan and Letcher counties* Its southern and eastern boundaries are irregular, being largely the
HINBBAli KBSOI'RC-KS 01' VIH(iI
Fig. 2. — General view of the Crane* N'e«t Coal ant) Coke Cumpany's tipple, Toms Creek.
COAL IXCLIXE ASD TIPPLE, BIG STONE CW COAL ¥\t\.B, \\Wi\lft\K.
GOAL AND ITS BY-PRODUCTS. 366
southern margin of the coal measures. As developed at present the field has an approxunate area of 540 square miles in Virginia and Kentucky. The area is a part of a long and narrow basin which extends northeast and southwest, and is bounded on either side by sharp and rocky ridges. The natural passageway in and out of this field is Big Stone Gap in Wise county, from which the field received its name. Several lines of railroad utilize this passageway which forms one of the principal outlets from the field.
The building of the Clinch Valley division of the Norfolk and Western Railway in 1891, marked the beginning of developments in the Big Stone Gap coal field. Although opened up nearly 10 years after the famous Pocahontas field, it is much the largest producer of coal and coke, and Wise county is, at present, the largest coal- and coke-producing county in the State. It is estimated that the :field produces about 80 per cent, of the Virginia coke output.
THB COAL.
There are 8 workable seams of coal in the district, ranging in thickness from 3.5 to 12 feet, and included within a vertical distance of about 1,200 feet. Of these the 4 highest have their greatest development in the western part of the district. Deep cutting by the streams and light dip of the strata are conducive to economic mining over much of the field.
Campbell divides the field into four separate basins, as follows: (1) The Crab Orchard basin, which includes all the territory in Lee county lying north of Stone Mountain, known as Crab Orchard; (2) the Imboden basin, so named because of the great development of the famous Imboden coal seam, which includes the area drained by the Powell river through Big Stone Gap; (3) the Guest river basin, comprising the region east of Norton drained by Guest river, the principal stream; (4) the Kentucky basin, which lies wholly in Kentucky and forms a part of the Big Stone Gap field. For convenience the field is divided below into the eastern portion and the western portion, and separately discussed.
In the Big Stone Gap field, Campbell divides the measures in descend- ing order, into the following formations :
Thickness in feet.
Wise formation 1,276
Gladeville sandstone 120
Norton formation 1 ,280
Lee formation 1 ,530
366
MINERAL RESOURCES OF VIRGINIA.
Of these the Norton is the principal coal-bearing formation. Two sections measured by Campbell, one in the extreme eastern part of Wise county, the other in the western part of the same county, show the relations of the principal horizons of the Norton formation. Section No. II in- cludes 530 feet of the Norton, the Gladeville sandstone, and some higher beds.
Section No. 1, Extreme eastern pari of Wise county:
Feet. Inches Feet. Inches
1. Gladeville sandf^tone
2. Interval 150 0
3. Imhoden coal bed 4 5
4. Interval 260 0
6. Upper Banyier coal bed 3 0 to 7 0
6. Interval 100 0
7. Lower Banner coal bed 1 6 to 4 4
8. Interval 226 0 to 286 0
9. Kennedy coal bed 1 0 to 9 0
10. Interval 340 0
11. Tacoma coal bed 3 4 to 4 4
12. Interval 90 0
13. Jawbone coal bed 4 4 to 8 8
14. Interval to Lee formation 150 0
iSeriion No. 11, Western part of Wise county:
Feet.
1. Sandstone 46
2. "Cannel bed" 6
3. Thin bedded samUtone 29
4. Upper Splint bed 1
6. Concealed 68
6. Shale 16
7. Sandy shale 13
8. Lower Splint bed 2
9. Gladeville samlstone 122
10. Coal bed 2
11. Shale and concealed 11
12. Kelly coal bed 1
13. Interval 76
14. Imboden coal bed 6
16. Ck>ncealed 70
16. Sandstone 20
17. Coal and clay 4
18. Shale 10
19. Sandstone 105
20. Shale 110
21. Coal bed 0
22. Sandstone 10
Inches Feet. Inches
6 6 0 6 6 6 6 0 0 0 0 6
0 ,
7 to 13 1
0 0 8 0 0 0 8 0
COAL AND ITS BY-PRODUCTS. 367
OPERATIONS.
The principal operations in the Big Stone Qap coal field are given below in tabular form :
Name of Operation. Post-office.
Banner Coal Company Norton,
Barrowman Coal Company Banner,
Bear Creek Coal and Coke Company Tacoma,
Blockwood Coal and Coke Company Blockwood,
Bond Coal Company Wise,
Bnice Coal and Coke Company Coeburn,
Carbon Coal and Coke Company Norton,
Clinchfield Coal Company Dante,
(*rane8 Nest Coal and Coke Company Georgel,
Dawson Coal and Coke Company Fink,
Domestic Coal Company Raven,
Guest River Coal and Coke Company Esserville,
Imboden Coke Company Imboden,
Intermont Coal and Iron Company Big Stone Gap,
Nickles Coal and Coke Company Tacoma,
Norton Coal Company Norton,
Raven Collieries Company Raven,
Raven Fuel Company "
Raven Red Ash Coa 1 Company "
Richland^ Coal Company Coldron,
Russell Creek Coal and Coke Company Virginia City,
Seaboard Coal Company Seaboard,
Spruce Pine Coal Company Norton,
Stone Gap Colliery Company Glamorgan,
Stonega Coal and Coke Company Stonega,
St. Paul Coal and Coke Company St. Paul,
Swords Creek Coal and Coke Company Swords Creek,
Tacoma Coal and Coke Company Tacoma.
The Colonial Coal and Coke Company Dorchester,
Town Hill Coal Company Richland-*.
Virginia Iron, Coal and Coke Company Georgel,
Virginia Iron, Coal and Coke Company Banner,
Wise Coal and Coke Company Dorchester,
THE EASTERN PORTION OF THE FIELD.
Introduction. — Reference to section No. 1 above, on page 36G, will make -clear the relations between the different coals in this portion of the field, which occur in the Norton formation. There are six coal horizons in the Norton formation which afford promise of workable seams at some point within the field. Named in descending order, these are designated by Campbell as follows:
( 1 ) Edwards Seam.
(2) Upper Banner Seam.
(3) Lower Banner Seam.
(4) Kennedy Seam.
(5) Imboden Seam (?) so-called.
(6) Jawbone Seam.
368 MINERAL RESOURCES OF VIRGINIA.
These are found in different horizons in diflferent parts of the field. Usually the lower ones are confined to the eastern portion of the field, including the Kennedy, so-called Imboden, and Jawbone seamS; and the higher ones to the western, including the Edwards, Upper Banner, and Lower Banner seams. The coals of the higher group are reported to be remarkably regular in thickness and composition, while ihofle of the lower group are considered quite variable.
The Edwards seam, — This is the highest seam of coal in the Norto"*^ formation, and it is found in several outcrops near the summits of th^ highest hills in the northern part of the field. It is found about 150 fee^ below the base of the Gladeville sandstone, and 250 feet above the n highest or Upper Banner coal seam. It is exposed on the ridge west o Big Tom creek and on Sandy Ridge near the head of the Left Fork o Bussell creek. At the former locality, an opening shows a thickness of feet 5 inches of clean coal, and at the latter the thickness is practicall; the same, including a small shale parting near the top.
The Upper Banner seam, — The Upper Banner seam is found 400 fee below the Gladeville sandstone and 250 feet below the Edwards seam. 0 account of its thickness and persistence it is reported to be the most im — portant seam in the field and is a coking coal of great excellence. Camp- bell describes a constant feature of the seam to be a contained small sand^ — stone parting which varies from 1 to 3 inches in thickness. In the Guest:: liver and Tom creek portions of the field, in the vicinity of Tacoma,:^-. numerous openings are made on the seam showing a thickness ranging fronm. 4 feet to 7 feet 10 inches. East of Big Tom creek developments are les^ extensive than in the type locality and the seam does not hold quite th^s- same thickness. At several openings a reported thickness of 5 and ^ feet are given.
A section of the Upper Banner seam measured at the mine east o:^
Tacoma is reported as follows:
Feet. Inches
Coal 2 9
Slato parting, some conl 2 10
Ck)al 2 5
Sandstone parting 0 1
Coal 2 0
Total 10 1
The Lower Banner seam. — This seam is found at approximately 10^ feet below the Upper Banner seam. It is reported to be fully as persistcii.^ as the upper one but not so thick. In the Big Tom creek portion of th.^
I ;
t .
I •
i !
! I I
I*
II:
GOAL AND ITS BY-PBODUCTS. 369
field this seam shows a thickness of from 3 to 4 feet, but further eastward on Big Laurel Bun and between Lick creek and Austin's Oap the thickness is increased to 52 inches, and 6 feet 2 inches, respectively. From the Left Fork of Bussell creek eastward, considerable variation in the thickness of the seam is shown, but it is reported on the whole as making a fine showing. At the Greno-Bodine mines the seam is reported to be 4 feet to 4 feet 10 inches thick. The following section was measured by Gamp- bell on Little Looney creek :
Feet. Inches
Coal 1 0
Shale 2 0
Coal 1 8
ToUl 4 8
The seams described above are the most important ones developed in the vicinity of Tacoma.
The Kennedy seam, — This seam, the uppermost one of the lower group of coals, occurs at a distance of from 225 to 285 feet below the Lower Banner seam. Outcrops of the seam occur along the valley of Quest river as far as Coebum. It has been opened a short distance east of Banner Station; on the Left* and Middle Forks of Russell creek; on Lick creek at the foot of Austin's Gap ; and a few openings have been made on the seam farther eastward. Judging from the openings made on the seam it shows much irregularity in thickness, ranging from 2 feet 8 inches to 10 feet. Greater extremes than these are reported.
The Imboden (f) seam, so-called, — The position of the Imboden seam has been shown by Campbell to be 180 feet below the Gladeville sand- stone. He states that if this is correct the Imboden seam corresponds very closely, if it is not identical, with the horizon of the Edwards seam de- scribed above. The approximate interval between the Kennedy and the so- called Imboden seams is doubtfully given at about 340 feet. The so-called Imboden seam has been prospected a mile east of Tacoma, and small seams at about this horizon are reported at a number of places along the railroad between Tacoma and Coebum; also east of Little Tom tunnel. It has been opened on Bull Run imder the high trestle of the Norfolk and Western Railway where it shows a thickness of 40 inches of coal. It is reported opened again on Russell creek directly above the mine near Virginia City.
The Jawbone seam, — ^This is the lowest workable bed of coal known in the Norton formation. It is probably 150 feet above the base of the
370 lilNERAL RESOUBOES OF VIBOIKIA.
formation, and at the mine near Virginia City it is reported to be 90 feet below the so-called Imboden seam. The seam derives its name fiom Jaw- bone Hollow, a small tributary of Bull Run, where it was first opened. Here the coal is said to be irregularly bedded and containing a large parting of bony coal near the middle. The seam has been opened about 1 mile above the mouth of Dry Fork on the east side of Bull Bun; and it has been considerably developed on the Right Fork of Russell creek. Nmneroug openings have been made on the seam in the valley of Bull Run.
A coal found about 200 feet above the Lee conglomerate at Tacoma apparently splits into two seams farther east, one of which shows a thick- ness of from 8 to 10 feet on Russell creek and is mined as the Jawbone seam. Campbell gives the following section exposed in the creek at Tacoma:
Feet. Inches
Coal 0 2
Shale 0 3
Coal 0 7
Knife-edge parting
Coal 1 8
Dirty coal 0 8
Coal 1 6
Total 4 10
COALS IN THE VICINITY OF BIG STONE GAP AND THE WE8TEBN
PORTION OP THE FIELD.
Introduction. — In the western or Big Stone Gap portion of the field, the principal coals are found below the Gladeville sandstone in the Norton for- mation, as in the eastern field already described. Of the numerous coals known to exist in the Norton formation in this portion of the field two are more conspicuously developed than the others, namely, the Imboden and the Kelly seams. The Imboden seam is stratigraphically below the Kelly, its position being fixed at 180 feet below the Qladeville sandstone. The Imboden seam is the most famous and important of all the coals known in the field.
As may be seen from section No. II, on page 266, measured in the western ])art of Wise county, three coal horizons are recognized above the Gladeville sandstone, designated as follows, in ascending order:
(1) Lower Splint bed.
(2) Upper Splint bed.
(3) Cannel bed.
These coals occur in the Wise formation, which, according to Camph^ll, has an estimated thickness of 1,276 feet. Other coals are reported to occur
1 |jart (if i-i'ke oiens,
GOAL AND ITS BY-PBODUOTS.
371
abave the Cannel bed, but as yet very little is known of them in the Virginia portion of the field.
The Imiboden seam. — The Imboden seam is the most prominent one of the nmnerous coals in this field. It can be continuously traced from Norton to the Lee county line, and it is found at a vertical distance orf 180 feet below the Oladeville sandstone. If this position is correct, the Imbodeot eeam, according to Campbell, is found at about the same horizon SB the Edwards seam in the eastern portion of the field, described above. In the yicinily of Lee county the thickness of the Imboden seam is given as. 30 inches; in a small branch to the eastward it shows a thickness of 4 feet 6 inches; and still farther east is a section doubtfully indentified as the Imboden. It is:
Feet. Inches
COBl 1 0
Shale 5 8
Coal 2 0
Shale 0 6
Ck)al 3 6
Total 12 8
In the mine on Little Looney creek the Imboden seam varies in thick- ness from 5 to 9 feet. The entire thickness of 5 feet is solid coal. The following sections measured by Campbell at different places serve to show the variation in thickness and character of the Imboden seam :
Preacher creek:
Feet. Inches
Sandttone roof
Coal 11 0
Boinreoal 0 3
Coal../. 1 8
Clay 0 2
Sandstone floor
Total- 13 1
Mmdh of Whiiley Fork:
Goal
gbato ..,
Goal
Dirty coal
Goal
Shale cariying sulphur. Coal
Total 10 10^1
|
Feet. |
Inches |
|
1 |
6 |
|
1 |
4 |
|
2 |
2y, |
|
1 |
1 |
|
1 |
1% |
|
0 |
6 |
|
3 |
2y, |
Mud Lick creek:
Feet. Inches
Coal 1 10
Knife-edge parting
Coal 1 4
Bony coal 0 1
Coal 0 e
Bony coal 0 0
Coal 2 4
Total 6 7
Powell river, north of Norton:
Feet. Inches
Coal 4 0
Shale 0 2
Coal 4 0
Total 8 2
372 inNBRAL RESOURCES OF VIRQINIA.
Prom the section at the mouth of Whitley Fork, the seam thins to Block creek, where it is about 4 feet 2 inches thick.
One mile northeast of Norton: Guest river at the bend east of
Norton:
Goal 2 10 Coal
Clay 1 0 Clay
Coal 0 3 Coal
Clay 0 « Clay
Coal 1 10 Coal
Clay 0 8 Dirty coal
Coal 1 10 Coal
Shale
Total 8 11 Coal
|
Feet. |
Inches |
|
2 |
8 |
|
0 |
8 |
|
0 |
2 |
|
0 |
|
|
1 |
|
|
0 |
|
|
0 |
|
|
0 |
|
|
2 |
|
|
0 |
|
|
0 |
Shale
Coal
Total 9 6
The Imboden seam is a fine body of coal and it produces an excellent coke. Campbell states that the finest showing of coal in the field occurs on the headwaters of a small stream flowing south into Powell river, between Eoaring Fork and Bearpen creek. It is the Imboden seam having a thickness of 16 feet, 13 feet of which is without a parting.
The Kelly seam, — Prom 50 to 76 feet above the Imboden seam is the Kelly coal, which attains considerable thickness in places. Its greatest development is probably on Roaring Fork, where it shows a thickness of 7
feet 3 inches. The section here is :
Feet. Inches
Shaly coal 1 3
Coal 6 0
Total 7 3
It is reported to be less than 1 foot thick at Pioneer on Callihan creek, and, according to Campbell, it is generally variable throughout the field.
Seam just beneath the Oladeville sandstone, — So far as I am awaie, this seam has not received a definite name. It occurs at the top of the Norton formation, just beneath tJie Qladeville sandstone on Powell river, north of Norton, and it has a reported thickness of 3 feet. Throughout the valley of Callihan creek, it is reported to have a thickness of about 2 feet, but in Lee county it forms a workable seam. The opening near Morris Oap shows a thickness of 6 feet 8 inches; on Jones creek 5 feet; and on Big Looney creek 5 feet 5 inches.
Coals of the Wise formxition. — Of the numerous coals found in the Wise formation and above the G-ladeville sandstone, there are at least 3 which are of importance. These are the Lower Flint, Upper Flint, and Cannel beds.
OOIL AXD ITB BT-PBODUOie.
373
According to Campbell they have their greatest importance in the Kentucky portion of the field, although a goodly thicknese of the beda ia shown in places on the Virginia side. The uppermost one of the three, the Cannel bed, vhich is a persistent seam and is found at about ISO feet about the sandstone, shows the following section on the Virginia side :
Feet. Inches
Caunel ahale. . Canael coal. . .
Shale
Shalj coal., . .
Shale
Coal
Shale
Coal
Total. .
Xethodi of Hining. In the Pocahontas field the method of mining formerly used was the double-entry system with rooms driven opposite each other and at right- anglee to the main entries. The main eaitriea were 10 feet wide with a pillar of coal 50 feet wide between them. The rooms leading out from the entries on either side were spaced about 60 feet apart between centers; were driven 18 to 20 feet wide, supported by a pillar between them from 40 to 42 feet wide. After the mine was blocked out, systematic robbing of the pillars begun.
(Modified from
374 MINERAL RESOUROES OF VIRGINIA.
At present the panel system of mining is employed with 15 to 25 rooms to each panel and systematically robbing all pillars that have been left. (Figure 55.) The panel system, a modification of the double-entry system, is said to have been introduced in order to avoid the waste of coal due to squeezing, following the robbing of pillars under the double-entry system. The rooms are driven opposite each other and at right-angles to the main entries. The method of mining at the Baby and West mines of the Pocahontas Collieries Company is entirely on the panel system, with 26 rooms to the panel. Large barrier pillars are left to protect haulways, and overcasts carry the air from each panel to the main return airway.
Ventilating fans of 300,000 to 500,000 cubic feet of air per minute are used, and are driven either by steam or by electric motors. Tracks are laid in the rooms from the main entries, and the cars are hauled out by either electric or steam locomotives.
At the new mines now opening up at Boissevain, 3 miles west of Poca- hontas, the system of mining will be varied in accordance with the structure of the vein. It is reported that three systems will be used: (1) Where the dip of the seam is less than 6 per cent.; (2) where the dip is between 5 and 20 per cent.; and (3) where it is greater than 20 per cent
In the Big Stone Gap field the method of mining employed is the room-and-pillar system, with the undergroimd haulage by mules and electric locomotives. Ventilating furnaces are in use at many of the mines, and exhaust fans are used as the mines become more extensively worked.
GOAL AND ITS BY-PBODUCTS.
376
Prodnotion.
Coal production of Virginia, from 1822 to 1906, incluswe.
Qaantity (Short tons)
54.000 60,000 67,040 75,000 88,720 04,000 100,080 100.000 102,800 118,000 132,000 125,000 124,000 120,000 134,000 160,000 300,000 396,000 424,894 379,600 373,640 370,000 365,000 350,000 340,000 325,000 318,000 315,000 310,000 310,000 325.000 350,000 370,000 380,782 352,687 363,605 377,690 359,055 473,660 445,165 445,124 40,000
Year
1864. 1865. 1866. 1867. 1868. 1869. 1870. 1871. 1872. 1873. 1874. 1875. 1876. 1877. 1878. 1879. 1880. 1881. 1882. 1883. 1884. 1885. 1886. 1887.
Qaantity (Short tons)
40,000
40,000
40,000
50,000
59,051
65,000
01,803
70,000
09,440
67,200
70,000
60,000
55,000
50,000
50,000
45,000
43,079
50,000
112,000
252,000
336,000
567,000
684,951
825,263
1888 1,073,000
1889 865,786
1890 784,011
1891 736,399
1892 675,206
1893 820,339
1894 1,299,083
1895 1,368,324
1896 1,254,723
1897 1,528,302
1898 1,815,274
1899 2,105,791
1900 2,393,754
1901 2,726,878
1902 3,182,993
1903 3,451,307
1904 3,683,914
1905 4,275,761
1906 4,275,815
376
MINERAL RE80UBCES OF VIRGINIA,
Coal production in Virginia by couiUies from 1900 to 1905,
(Short Tons).
|
(bounty. |
1900 |
1901 |
1902 |
1903 |
1904 |
1905 |
|
MoDtgomerj Tasewell |
9,814 970,863 1,363,670 40,178 9,326 |
11,177 776.668 1,918,693 11,760 7,676 |
12,786 723,763 2,422,417 16,206 7.831 200 |
. 20,288 840,196 2,663,286 18,084 9,266 300 |
21,628 871,720 2,614,133 2,100 174,033 300 |
|
|
961,380 2,990,698 |
||||||
|
wise .■•••■••• • . • Chesterfield... ) Uenrico Pulaski ..\ Bussell / Small mines |
||||||
|
323,073 120 |
||||||
|
Total |
2,393,764 $2,123,222 |
2,726,873 $2,363,989 |
3,182,993 $2,643,696 |
3,461,307 $3,302,149 |
3,683,914 $2,921,911 |
4275,271 |
|
Total values... |
$3,777,325 |
^Includes Lee and Montgomery Ck>untle8.
Beferences.
The coal bibliography of Virginia is rather a voluminous one. Only the more important references to the literature can be noted in this volume.
Adkinson, W. Q. The Catawba, Botetourt County, Virginia, Coak The
Virginias, 1883, IV, 160-161.
Campbell, M. E. Geology of the Big Stone Gap Coal Field of Virginia
and Kentucky. Bulletin No. Ill, U. S. Geological Survey, 1893, 106 pages.
(Jeologic Atlas of the United States, Estillville Folio, No. 12. U. S. Geological Survey, 1894.
Geologic Atlas of the United States, Pocihontas Folio, No. 26. U. S. Geological Survey, 1896.
Geologic Atlas of the United States, Tazewell Folio, No. 44. U. S. Geological Survey, 1898.
Geologic Atlas of the United States, Bristol Folio, No. 59. U. S. Geological Survey, 1899.
Clifford, William. Kichmond Coal Field, Virginia. Transactions
Geological Society of Manchester, 1888, XIX 326-353, 431-433; Ibid. 1889, XX, 247-256.
Eastern Virginia Coal Field. Transactions Amen- can Institute of Mining Engineers, 1874-6, IH? 228-231.
Coryell, M.
Fontaine, W. M.
Notes on the Mesozoic Strata of Virginia. American Journal of Science, 1879, XVII, 25-39, 151-157, 229-239.
GOAL AND ITS BY-PRODUCTS.
377
Fowler, Qeo, L.
Hayes, C. W.
Heinrich, 0. J.
Hodge, J. M.
Hotchkiss, J.
The Coals and Goal-Mining Methods of the Pocahontas Field. The Engineering Magazine, 1904, XXVII, 217-232.
The Coal Fields of the United States. 22nd Annual Report, U. S. Qeological Survey, 1900-01, Part III, 7-24.
The Midlothian Colliery, Virginia. Transactions American Institute of Mining Engineers, 1871-3, 1, 346-369, 360-364; Ibid. 1875-6, IV, 308-316; Ibid, 1876-77, V, 148-161.
The Mesozoic Formations in Virginia. Transactions American Institute of Mining Engineers, 1878, VI, 227-274 ; The Virginias, 1880, I, 124-125.
The Big Stone Gap Coal Field. Transactions Ameri- can Institute of Mining Engineers, 1892-3, XXI, 922-938. Discussion by M. R. Campbell, 1004- 1005.
The Coal Fields of West Virginia and Virginia in the Great Ohio, or Trans-Appalachian Coal Basin. The Virginias, 1880, I, 18-21.
The Great Flat Top Coal Field and the New River or Lower Coal Measures Coals. The Virginias, 1881, II, 153; Ibid. 1882, III, 88-89, 92-93; Ibid. 1883, IV, 51.
The North Mountain Coal Field in Botetourt County, Virginia. The Virginias, 1883, IV, 146-147.
The Richmond, Virginia, Coal Field. The Virginias, 1883, IV, 171.
On the Structure and Probable Age of the Coal Field of the James River, near Richmond, Virginia. Quarterly Journal Geological Society (London), 1847, III, 261-280.
McCreath, A. S. and d'Invilliers, E. V. Mineral Resoiirces of the Cumber- land Valley of Southeastern Kentucky and South- western Virginia. Louisville, Kentucky, 1902, 152 pages.
Newell, F. H. Richmond Coal Field, Virginia. Geological Magazine,
Decade III, 1889, VI, 138-139.
Parsons, F. W. and Leckie, Wm. The Pocahontas Collieries Company.
Engineering and Mining Journal, 1906, LXXXII,
782-786.
Lyell, Sir Charles.
378 MINERAL EEBOUROES OF VIBGIKIA.
Rogers, Wm. B. The Great Coal Field of the Virginias. The Virgi- nias, 1882, III, 158-159, 164.
Reprint of the Geology of the Virginias- New York, 1884.
Russell, I. C. Correlation Papers. Newark System. Bulletin No. 85,
TT. S. Geological Survey, 1892.
Sehraitz, E. T. The Structure of the Richmond Coal Basin. Trans-
actions American Institute of Mining Engineers, 1896, XXIV, 397^08.
SnaJer, N. S. and Wood worth, J. B. Geology of the Richmond Basin,
Virginia. 19th Annual Report, U. S. Geological Survey, Part II, 1897-98, 385-519.
Stevenson, J. J. Notes on the Quinnimont Coal Group in Mercer
County of West Virginia and Tazewell County of Virginia. Proceedings, American Philosophical Society, Philadelphia, 1880-81, XIX, 498-505.
Geological Reconnaissance of Paris of Lee, Wise, Scott, and Washington Counties, Virginia. Pro- ceedings, American Philosophicad Society, Phila- delphia, 1881, XIX.
Carboniferous of the Appalachian Basin. Bulletin Geological Society of America, 1904, XV, 147-156.
Woodwori;h, J. B. The History and Conditions of Mining in the Rich- mond Coal Basin, Virginia. Transactions Ameri- can Institute of Mining Engineers, 1902, XXXI, 477-i84.
2. CAEBONTTE (NATURAL COKE).
Carbonite, natural coke, occurs in the Richmond coal basin and is a modification of the normal coal due to the heat of intruded localized masses of igneous rocks (diabase). It has been mined especially on the east side of the basin at Carbon Hill and Midlothian.
The natural coke varies much in quality and texture, ranging from a dense, amorphous graphitic-looking material to that which in general aspect, especially in the prismatic form of the masses, resembles the non- compact varieties produced in modem ovens. Prom the origin of the coke and the differences in the original composition of the coal from which it has been derived, it is irregular in distribution and variable in quantity. Data are lacking upon which to base an estimate of the proporidon of the coal of the basin which has been coked by the igneous masses. According
GOAL AND ITS BY-PRODUOTS. 379
to Woodworth probably less than one-fifth of the coal has undergone this change to coke.
Sufficient tests of its economic value have not been made, although the coke has long been in use as a domestic fuel and it is highly esteemed locally. It is denser than artificial coke and has more nearly the quality of anthracite coal. Adequate tests have not been made to ascertain its fitness for metallurgical work.
Samples of the coke were analyzed by S. B. Riggs in the laboratory of the U. S. Geological Survey with the following results:
Per cent.
Carbon 67.13
Volatile matter 18.35
Ash 12.86
Water 1.66
Total 100.00
Sulphur 4.70
Samples of the carbonite from the Jewett and Brother^s Colliery on the east side of the basin were separated into two portions, a dull and a lustrous portion, and separately analyzed by Doctor Drown with the follow- ing results:
Dull Portion Lustrous Portion Per cent. Per cent.
Carbon 79.33 81.52
Volatile matter 16.47 11.10
Ash 3.20 6.68
Lo88atl00**C 2.00 0.69
Total 100.00 100.00
Sulphur 4.08 1.60
Specific gravity 1.375 1.360
Beferenoes.
Raymond, R. W. The Natural Coke of Chesterfield County, Virginia.
Transactions American Institute of Mining Engi- neers, 1882-83, XI, 446-450.
Riggs, R. B. Analysis of Natural Coke from Midlothian, Virginia.
Bulletin No. 42, U. S. Geological Survey, 1887, 146.
Rogers, W. B. On the Porous Anthracite or Natural Coke of Eastern
Virginia. American Journal of Science, 1842, XLIII, 175-176.
Natural Coke in Virginia, Proceedings, American Academy of Arts and Sciences, 1854, III, 106-107.
380 MINERAL RESOUBOES OF YIRGIKIA.
Observations on the Natural Coke and the Associated Igneous and Altered Bocks of the Oolite Coal Region in the vicinity of Bichmond, Virginia. Proceedings Boston Sociely of Natural Hi^ry, 1854-56, V, 53-56; The Virginias, 1888, IV, 158-159.
Shaler, N. S. and Woodworth, J. B. Gteology of the Bichmond Baaiii, Vir- ginia. 19th Annual Beport, XT. S. ' Geological Survey, 1897-98, Part II, 511.
Wurtz, H. Preliminary Note upon the Garbonite or So-called
Natural Coke of Virginia. Tran8acti<»B American Institute of Mining Engineers, 1874-76, m, 456- 458.
3. COKE.
The rapid development of the excellent coking-coal fields in fiouth- wcstern Virginia during the last few years has made Virginia one of the prominent coke-producing states. The State now ranks fourth among the coke producers. Prior to 1895 there were only two coke-making establishments in Virginia, with a production of less than 200,000 tons per year. The number of establishments increased to 7 in 1901, and the total number of coke ovens increased from 832 in 1896 to 2,775 in 1901, with a total production of more than 900,000 short tons. Construc- tion and development work progressed rapidly during 1902, the number of establishments was doubled, and at the close of the year 2,974 ovens were built and 1,208 were building, with a production increased to 1,124,572 short tons.
In 1903, 2 more establishments were added, making the total number 16, with a total of 4,251 ovens, and the production further increased to l,17r),439 short tons. In 1904, there was an increase of 94 completed ovens, the number of establishments remaining the same as in 1903, while the production declined to 1,101,716 short tons. Two establishments, having a total of 107 oven?, wore reported idle during the year 1904. One of these was the Newton-Chambers ovens at Pocahontas in Tazewell county.
The product in 1905 amounted to 1,499,481 short tons, an increase of 36.1 per cent, over 1904. The value, $2,869,452, increased 62 per cent over 1904. The number of ovens increased to 4,549 in 1905.
The remarkable increase in coke-production in Virginia during the last few years has resulted from the development of the Wise county coal fields on the Clinch Valley division of the Norfolk and Western Kailway.
UINSRAL RESOURCES OF VIRGINIA.
r of Osaka No. 1 coal tipple.
Fig. 2.— General view of double batterips of ci>l;c ovens at Osaka. »AL TIPPLE AND COKE OVENS. BIG STONE GAP COAL FIELD. VIRGINIA.
"^
.■■■J •
CX)AL AND ITS BY-PRODUCTS.
381
With the development of the enormous coal reserves in the adjacent south- west Virginia counties should follow, in the very near future, a greatly increased coke-making output from the State.
All the coal used in coke-making in Virginia up to 1895 was unwashed. Washing slack coal b^an in 1896, and in 1898 the amount of washed slack coal used amounted to more than 210,000 short tons.
Analyses of Virginia Coke.
Analyses of coke made from ike southwestern Virginia coals.
Mobtore
Volatile matter
Fixed carbon
Ash
Solphor
Phoe- ghorua
Analyst
Ck)ke made from the Pocahontas or Flat Top Coal
0.29 0.09 0.664 0.680
0.847
Per cent
0.59 1.10 1.059 1.74 3.28 0.757 16
Percent.
93.84
93.67
92.816
92.92
91.37
92.55
91.39
Per cent
5.28
5.14
4.913
4.66
5.25
6.749
6.45
Per cent.
0.357
0.620
0.548
0.619
0.72
0.597
(By-Product Coke)
H. Froehling, Richmond, Va. Prof. Hile, Morffantown, W.Va. A. S. McCreath, Harrisbarg, Pa. Western Steel Co., St. Louis, Mo. Joliet Steel Co., Chicaso, 111. A. I. M. £., Boston, Mass. Dora Furnace Co., Pulaski, Va.
Coke made from the Big Stone Gap Coal
0.35
91.36
8.29
0.68
0.034
Made from Soott Co., Va., coal
An analysis of the ash given in the first analysis of the above table, from the coke of the Pocahontas or Flat Top coal field, gave Doctor Froehling the following results:
Per cent.
Silica 2.780
Alumina 1.009
Iron oxide 881
Lime .341
Magnesia 016
Phosphoric oxide 018
Sulphur trioxide 158
PoUsh 068
Maganese oxide trace
Total 5.271
382
MINERAL RESOUBOES OF YIBGINIA.
Analyses of coke made from coal in th^ Big Stone Oap field. Wise coutdy.
Name of producer.
Fixed carbon.
Volatile matter.
Per ct Per ct
Ash.
Perct
Sul- phor.
Perct
Ck)loiiial Coal & Coke Co... 88.37 !
Colonial Coal & Coke Co... 88.14 l
Wiae Coal & Coke Co 88.75 '
Wise Coal & Coke Co ' 88.41 I
Norton Coal Co 94.45 !
Norton Coal Co 93.43 ,
|
1.43 |
10.20 |
0.82 |
|
1.56 |
10.30 |
0.89 |
|
1.45 |
9.80 |
0.73 |
|
1.43 |
10.16 |
0.83 |
|
1.60 |
3.95 |
0.75 |
|
1.75 |
5.44 |
0.726 |
PhOA-
phoms
Perct
0.034
Amljit
F. W. Gtnor. F. W. Giner. F. W. Gaaer. F. W. Ganer. fi. W. DoRctt Booth; QairettABlur.
The character of the coal used in the manufacture of coke in Viiginii since 1890 is shown in the following table:
Character of coal used in the manufacture of coJce in YirgyMa, 1890-
1906.
(Short Tons.)
|
Run oi |
mine. |
Slack. |
|||
|
Year. |
Total. |
||||
|
Unwashed. |
Washed. |
Unwashed. |
Washed. |
||
|
1890 |
98,215 |
0 |
153,468 |
0 |
261,683 |
|
1891 |
107,498 |
0 |
177,616 |
0 |
286,113 |
|
1892 |
106,010 |
0 |
120,507 |
0 |
226,617 |
|
1893 |
107.498 |
0 |
86,561 |
0 |
194,059 |
|
1894 |
103,874 |
0 |
176.650 |
0 |
280,624 |
|
1895 |
114,802 |
0 |
295,935 |
0 |
410,737 |
|
1896 |
70,756 |
0 |
370.624 |
13,584 |
454,964 |
|
1897 |
286,158 |
0 |
227.363 |
61,021 |
574,642 |
|
1898 |
405,399 |
0 |
237,474 210.099 |
862,972 |
|
|
1899 |
612,267 |
0 |
225,118 |
157,260 |
994,635 |
|
1900 |
620,207 |
0 |
463,620 0 |
1,088,827 |
|
|
1901 |
869,203 |
0 i |
531,028 |
0 |
1,400,231 |
|
1902 |
1,018,148 |
0 |
697,962 |
0 |
1,716,110 |
|
1903 |
857,332 |
0 |
1,002,893 |
0 |
1,860,225 |
|
1904 |
1,213,226 |
44,222 |
379,457 |
0 |
1,636,905 |
|
1905 1 |
1,096,656 |
0 |
1,087,713 |
0 |
2,184,369 |
The following are the statistics of the manufacture of coke in Virgiflifl from 1883 to 1906:
.J
UINERAL BBSOURCB8 OF VIBQINIA.
PLATB LXII.
Fig. 2. — tipneral view ot coke ovens, upper bntterie*. nt [mliiMlen. COKE OVENS, UIG STONE GAP COAL F[ET,n, VIRGINIA.
i
1
I t
in a
••
II
GOAL AND ITS BY-PBODD0T8.
Statistics of the manufactvre of cohe in Virginia, 188S-190S.
Cok« produced. Slutrilimi.
m
|
101 |
|
110 ' |
|
0 |
|
420 |
|
300 1, |
|
0 1. |
|
1,208 1, |
|
142 I, |
|
fl8 1 1, |
|
0 2, |
200, OlS 235,841 230,629
238,793
194.059 230,524 410.737 464,994 674,542 852,972 994,635 083,827 400,231 716,110
49.139 122,352 166.947 140, 19y 146,528 165,847 167,516 147.912 125,092 180,091 244,738 268,081 354,097 531,161 818,707 686,156 907,130 1,124,572 1,176,439 1,101,716 1.499,4D1
S 44,345
111,300
85,993
305,880
417,368
260.1100
326,861
278.724
265,107
322,486
282,808
205,747
322,564
404,573
495,864
699,781
1,071,284
1,464,556
1.483,670
2,322,228
2,724,047
1.772.717
2.869,452
68.8 65.3 64.5 64.2
•Include!) 68 Newton-(
In the following table is given the productioD of coke i by-product ovens in 1902 to 1904:
Virginia in
|
Y«M. |
Quantity. Short l»^. |
Yield per ton of coal. Ptretni. |
Value per ton. |
ToUl vtluo. |
|
IV02 190S 1904 |
36,748 33,766 27,337 |
54.8 60.6 56.5 |
J3.76 3.30 3.60 |
I0K53S 111,467 98,387 |
4. GAS, TAB, Am) AHXONIA (BT-FBODUCTS OF COKE WOBES).
In the bee-hive form of coke ovcdb all gases and by-products were allowed to go to waste, a condition which is now being largely remedied by the use of the by-product ovens. This fonn of oven is coming into greater DBe, although it is claimed that it does not produce coke with a silvery
MINERAL SEBOtmCBB OF VIRGINIA.
luater like that from the bee-hire oven, but the Btnictuie and quality of the by-product coke is not much inferior to the old bee-hive product.
The following tables, compiled from the recent volumes of the Mineral Sesourcee, show the production and value of gas, tar, and ammonia, pro- duced at by-product coke works and in gas-house retorts in Virginia from 1902-1905.
Under Coke on page 383, is given a table showing the production and value of coke produced in Virginia in by-product ovens from 1902-1905.
Tahle showing quantUy and value of gas produced and sold at by-prodnct coke plants in Virginia from 190S to 1906.
|
si' 31 A |
OtuHildRirllliim- InatHig purpose* |
GHfl Bold for fuel pur- |
Total ga. Bold |
Ml |
||
|
i |
quantity Value S | Cublp p-a fivL s -j^ |
ruble |
741 |
Cubic |
Value ' g§d ' * |
i |
|
IK! isS.SSli:!! |
as |
IF |
s _«»« |
The following table gives the coal-tar production in Virginia from 1908 to 1905:
|
Year. |
Namber of |
8=2" |
Value. |
Value per gallon |
Yield per ton of coal. |
|
1802 1903 1S04 1905 |
U 13 |
461,317 60«,994 603,400 691,530 |
I20.4B3 25,293 18,119 21,152 |
4.40 4,16 3.60 3.06 |
6.88 10.89 10.22 12.40 |
In the table below is given the production of anunonia liquor in Vir- ginia and West Virginia at the gas and by-product coke works from 1902 to 1905. The returns do not separate Virginia and West Virginia :
|
Year. |
CmU orboDiMd. |
EquivaUnt to aoh;- |
|
|
1902 ]»)3 l»4 1905 |
268,606 219,481 238,461 178,398 |
1,062,817 767,186 1,183,006 1,073,102 |
1,811.716 1,108,472 1.336,085 1,002,068 |
MISCELLANEOUS. 385
XI. MISCELLANEOUS.
1. GEHMINEBALS.
Under this heading are grouped those minerals which are distinguished, when cut and polished, for their beauty, durability, or rarity. The essen- tials, beauty and durability, are dependent upon color, brilliancy, and hardness of the mineral, which in turn are dependent upon the chemical and physical properties of that particular mineral.
Distribution and Localities.
A variety of minerals of gem grade have been foimd in the crystalline rocks of the Piedmont province of Virginia. Some counties in this area, which seemingly offer good possibilities for the occurrence of gem ma- terials, have not yet been exploited for this purpose. The known counties which have either produced gem minerals, or contain minerals which might be of desirable gem grade, are Amelia. Amherst, Bedford, Buckingham, Fairfax, Hanover, Nelson, and Spottsylvania. Of these, Amelia county is the best known and has produced the largest variety and quantity of gem minerals. These have come from the mica mines opened in the pegmatite dikes, near Amelia court-house.
Those minerals known to occur in Virginia which have been used or are capable of being used for gem material are separately described below.
Diamond.
The largest diamond discovered in the United States up to 1884 was found by a laboring man at Manchester, Virginia, in 1855, in some earth he was digging. So far as known to the writer this marks the only diamond-find in the State. A writer states that this stone was put into a furnace for melting iron at Eichmond, where it remained at red heat for 2 hours and 20 miuutes, and when taken out it was found to be uninjured. It was valued in Eichmond at that time at $4,000.00 and was later cut at an expense of $1,500.00. Its form was that of a slightly rounded trigonal trisoctohedron, and in the rough it weighed 23% karats ; after cutting its weight was 11 11-16 karats. In color it was a faint green- ish white with perfect transparency, but the refraction was somewhat im- paired by a flaw or speck in the interior.
386 MINERAL RES0UB0E8 OF YIBOINIA.
It has been suggested that the stone was brought down by the James river during spring floods from the Virginia gold fields. Exact copies of this gem, in glass, as it was found and as cut were deposited in the United States Mint Museum in Philadelphia, and at the Peabody Museum in New Haven, Connecticut.
Quartz.
Several varieties of quartz are found in Virginia from which a few gems have been cut. These include a greenish colored banded quartz; a milky-white chalcedony ; colorless quartz with dark inclusions ; and a smok}^-brown quartz. These have come from one locality, namely, Fair- fax court-house. Gems cut from each variety of the Fairfax court-house quartzes named above are included in the collection of gems in the United States National Museum.
In the cabinet of Tiffany and Company of New York City, is a fine limpid crystal of quartz, one inch long and two-thirds of an inch in diame- ter, penetrated by fine green crystals of actinolite a half millimeter in di- ameter, from an unknown Virginia locality.
Amethyst, a variety of quartz, has long been knovm to students and collectors as occurring in Virginia. A promising locality has recently been opened and some good gem mineral taken out at a point about 2 miles from Lowesville post-office in Amherst county, and about the same distance from the James river. It occurs in pockets connected with a well-marked vein of white quartz, which extends for some miles along the base of the Blue Ridge. It occupies an area of about 11 acres, and the amethyst oc- curs but a few inches below the surface. The deposit has been only slightly exploited.
Garnet.
Beautiful transparent spessartite, a manganese-aluminum garnet, used a? a gem, is found at the mica mines near Amelia court-house, in Amelia county. Irregular masses of the spessartite variety of gamtt v/ith crystalline exterior have been obtained from the Amelia court-house mines, which on cutting finished fine gems very similar in color and luster to the essonite or hyacinth of Ceylon. The cut stones varied from 1 to 100 karats in weight.
According to Kunz, George W. Fiss, of Philadelphia, found some of the most beautiful natural gems of microscopic yellow garnets from the mica mines of Amelia county. In his "Descriptive Catalogue of the Collections cf (icfiis in the United States National Museum," Tassin lists 9 gems cut from the Amelia county spessartite with the following weights: 39.13, 7.26, 2.;?8, 2.G0, 1.10, 11.51, 8.89, 9.32, and 5.65 karats.
MacELLLtrBOVS. 387
AnaljseB of the Amelia oounty spaasartite by Bradbnrj and Clarke are giTen on page 288.
Andradite.
A calcium-iron garnet, nsnallv of black color, has also been reported friHn the Amelia connty mines. Topasolite, a sub-variety of andradite, baring the color and transparency of topaz, also occurs in the same mines, near Amelia court-house.
Beryl.
Beryls of large and small size in more or less perfect crystals are found in the mica mines of Atth^Ha^ county. Beryl of pure white color has been noted from these mines. An analysis made by Baker of the Amelia county beryl gaye:
Per cent.
Silica 65.24
Alumina 17.05
Ferric oxide 2.20
Beryllium oxide 12.64
Lime 0.57
Soda 0.68
Water 2.70
ToUl 101.08
Specific gravity 2.702
Apatite.
Crystals of apatite are found in association with the mica, beiyl, etc.,
in the Amelia count}- mica mines. Some of the apatite crystals are of
very large size. An analysis made by Bowan of a specimen of apatite from
the Amelia county locality gave:
Per cent.
Lime 63.94
Phoephoric acid 41.06
Alumina 0.19
Ferric oxide 0.81
Fluorine 3.30
Chlorine trace
Ignition 0.81
Insoluble reeidue 0.63
ToUl 100.74
Specific gravity 3.161
Allanite.
Allanite is known in Bedford, Amelia, Amherst, and Nelson counties, Virginia. It occurs in considerable quantity in Amherst county, where
388 MINERAL RESOURCES OF VIROINIA.
it is found in large masses and crystals, very compact and black in color, and would form a black metallic gem stone. It is found in large masses in the Amelia county mica mines.
Analyses of allanite from Amelia, Bedford, and Nelson counties, gave:
Bedford Amelia Nelson
County. County. County.
Per cent. Per cent. Per cent.
Silica 26.70 32.35 30.04
Alumina 6.34 16.42 16.10
Ferric oxide 3.21 4.49 6.06
Cerium oxide 33.76 11.14 11.61
Didimium oxide 16.34 6.91 5.39
Lanthanum oxide 1.03 3.47 4.11
Ferrous oxide 4.76 10.48 9.89
Erbium oxide 0.52
Manganous oxide trace 1.12 trace
Lime 2.81 11.47 13.02
Magnesia 0.54 1.11
Soda 0.49 ) ^ . - f 0.28
Potash 0.55 l "**'* t 0.02
Water 1.99 2.31 2.56
Tin oxide 0.17
Total 99.04 100.62 99.36
Eyanite.
This mineral, a silicate of aluminum, is found at Willis Mountain, in Buckingham county; in the vicinity of the old mica mine near Hewlett's, in Hanover county; and 2 miles north of Chancellorsville, in Spottsyl- vania county. As yet no really fine gems have been produced from any of the American kyanite.
Fluorite (CMorophane) .
One of the most remarkable varieties of this mineral, chlorophane, is found at the mica mines in Amelia county. It fluoresces by the heat of the hand, thus affording a fluorescent gem stone, but not hard enough for anv kind of wear.
Kunz says of the Amelia county chlorophane : *^t is a fact of much interest that the variety of fluorspar found at Amelia, Va., has been found extremely sensitive to heat, so that it becomes distinctly luminous by the warmth of the hand, and that it also shows a triboluminescence so marked that the slightest friction will cause it to emit a phosphorescent light. A spectroscopic examination by Humphreys of the Amelia county chloro- phane showed that yttrium was present and ytterbium in some.'
For other occurrence of fluorite in Virginia see page 215.
w
MISCELLANEOUS. 389
Feldspar.
The numerous pegmatite dikes found penetrating the metamorphic rocks of the crystalline or Piedmont region, east of the Blue Ridge, fre- quently contain feldspar of gem grade. The most noted locality in Vir- ginia where feldspar of gem grade is found, and which has produced moon- stones in some quantity, is that of the mica mines near Amelia court- house, in Amelia county. Three species of feldspar from the Amelia court-house mines have yielded gems. These are the green-colored potash feldspar, microcline, and the soda and soda-lime feldspars, albite and oligoclase.
Microcline, variety amazonsione, is found near Amelia court-house of rich green color. An elliptical girdle, a small tray, and two small balls, 2ut from amazonstone of the Virginia locality, are in the collection of gems in the United States National Museum.
Alhite and Oligoclase, variety moonstone, occurs near Amelia court- house, varying from colorless to white, opaque, vdth fine change of color. A goodly number of moonstones from the Amelia county mines, of double and single cabochon cut, elliptical girdle, are in the gem collections of the United States National Museum.
The finest examples of moonstone from an American locality, very closely resembling the Ceylon in quality and transparency, are found at Amelia court-house. Analyses of both the amazonstone and the moon- stone from the Amelia county mines are given on page 277.
Hicrolite.
The rare mineral, microlite, which is essentially a calcium pyro- tantalate containing niobium, fluorine, and a number of bases in small amount, is found in Virginia, only at the Amelia county mica mines, in association with beryl, spessartite, fluorite, etc. The microlite occurs in the Virginia locality in fine crystals up to 1 inch in diameter, and in imperfect crystals up to 4 pounds in weight.
Where the mineral has been found at other localities it waa opaque or at best translucent and not of value as a gem stone. At the Virginia local- ity, however, some of it is of sufficient transparency to be highly prized as a gem, the color varying from an essonite red to that of a rich spinel yellow, and remarkably brilliant. It is remarkable for its density, having a specific gravity higher than that of any known gem, being about 6.
390 MINERAL RESOURCES OF VIRGINIA.
An analysis of the Amelia county microlite yielded Professor Duimiiig- ton the following results :
Per cent.
Ta,0, 68.43
Nb,0. 7.74
WO. 0.30
SnO, 1.05
CaO 11.80
MgO 1.01
BeO 0.34
UO. 1.69
Y,0« 0.23
(Ce, l>i),0, 0.17
Fe,0, 0.29
A1,0« 0.13
Na,0 2.86
K,0 0.29
H,0 1.17
F 2.86
Total 100.26
Specific gravity 5.666 (Duimiiigton)
Specific gravity 6.13 (Hidden)
Coltunbite.
Columbite, a niobate and tantalate of iron and manganese, occurs in the Amelia county mica mines with microlite in fine splendent crystals. An analysis of the columbite from Amelia county gave Professor Dun- nington :
Per cent.
NbA 31.40
Ta^Os 53.41
SnO, trace
FeO 5.07
MnO 3.05
CaO 1.27
MgO 0.20
YA 0.82
Total 05.22
Specific gravity 6.48
Helvite.
This mineral is of yellow color and is found filling cracks in sp^' sartite at the mica mines near Amelia court-house. Sloan and HaiDCS give the following composition of the mineral from the Virginia locality-
MISCELLANEOUS.
391
Sloan, B. E.
Analyst
Per cent.
SiO, 25.48
BeO 12.63
MnO 39.07
FeO 2.26
Mn 8.66
S 4.96
A1,0« 2.96
CaO 0.71
K,0 0.43
NaaO 1.01
ToUl 98.16
Haines, R. Analyst Per cent.
31.42 10.97 40.56
2.99
8.59
4.90
0.36
99.79
Baker, A. L.
Bradbury, C. M.
Clarke, F. W.
Beferenoes.
Beryl from Amelia County. American Naturalist, 1882, XVI, 340 ; American Chemical Journal, 1885, VII, 175.
Garnet (variety Spessartite) from Amelia County, Virginia. Chemical News, 1884, L, 120; The Vir- ginias, 1885, VI, 25.
Mineralogical Notes. Spes8ari;ite from Amelia County, Virginia. U. S. Geological Survey, Bulletin No. 60, 1890, 129.
Dunnington, F. P. Columbite, Orthite and Monazite from Amelia Coun- ty, Virginia. American Journal of Science, 1882, XXIV, 153-154; American Chemical Journal, 1882-'83, IV, 138-140.
Helvite from Amelia County, Virginia. American Chemical Journal, 1882-'83. IV, 479.
Analysis of Columbite and Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611*.
New Analysis of Columbite and Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, Gil.
On Microlite from Amelia County, Virginia. Chem- ical News, 1881, XLIV, 44; American Chemical Journal, 1881, III, 130; American Journal of Sci- ence, 1881, XXII, 82.
Haines, B. Analysis of Helvite from Virginia. Proceedings
Academv Natural Sciences, Philadelphia, 1882, 101 ; Chemical News, 1883, XLVII, 6-7.
392
MINERAL RE80UKCES OF VIRGINIA.
Hidden, W. E.
Koenig, 6. A.
Kunz, G. F. Lewis, H. C.
Musgrave, E. N.
Page, C. C. Page, W. T.
Rowan, G. H. Seamon, W. H.
Sloan, B. E.
Tassin, Wirt.
A Transparent Crystal of Microlite, Amelia Court- House, Virginia. American Journal of Science. 1885, XXX, 82.
Notes on Orthite from Amelia Court-House, Virginia. Proceedings Academy of Natural Sciences, Phila- delphia, 1882, XXXIV, 103-104.
Chlorophane from Anlelia County, Virginia. Amer- ican Journal of Science, 1884, XXVIII, 235-236.
Holvite from Virginia, Amelia County. American Journal of Science, 1882, XXIV, 155; American Naturalist, 1882, XVI, 337-338.
An American Locality for Helvite, Amelia Court- House, Virginia. Proceedings Academy Natural Sciences, Philadelphia, 1882, XXXW, lOO-lOl.
Analysis of Albite from Amelia County, Virginia. Chemical News, 1882, XLVI, 204; American Nat- uralist, 1883, XVII, 312-313.
Amazonstone from Amelia county, Virginia. The Virginias, 1885, VI, 24-25.
Analysis of Allanite from Bedford County, Virginia. American Naturalist, 1883, XVII, 312-313 ; Chem- ical News, 1882, XLVI, 195.
Apatite from Amelia County, Virginia. The Vir- ginias, 1885, VI, 24; Chemical News, 1884, L, 208.
Analysis of Garnet from Amelia County, Virginia. American Naturalist, 1883, XVII, 312-313.
Analysis of Helvite from Amelia County, Virginia. Chemical News, 1882, XLVI, 195; American Naturalist, 1883, XVII, 312-313.
Analysis of the Feldspar Accompanying Microlite in Amelia County, Virginia. Chemical News, 1881, XLIV, 207 ; The Virginias, 1882, III, 4.
Descriptive Catalogue of the Collections of Gems in the United States National Museum. Report of the United States National Museum for 1900, 473- 670.
2. SAND.
Sand, suitable for the three principal uses made of it, is found in com- mercial quantity in Virginia. This includes sand used for glass mann- facture, molding, and building purposes. The principal production of
MISCELLANEOUS. 393
"N^irginia sand up to the present time is utilized in molding and for building purposes. Although commercial deposits of glass sand occur, there has been no production, as yet, for this purpose, in Virginia.
Glass Sand.
A purer sand is required in the manufacture of glass than that used for any other purpose. Sand suitable for glass manufacture is found at a number of localities in the State. Deposits of a fine white sand, derived by disintegration from the hard Potsdam sandstone, are found at several places along the eastern edge of the middle Valley region. An extensive deposit occurs at Balcony Falls in Eockbridge county, along the west base of the Blue Ridge. At Stapleton Mills, in Amherst county, is found a deposit of very pure white sand.
In the northern portion of Eoanoke county, in Catawba valley, and along Catawba Mountain, about 9 miles north and west of Salem, are deposits of fine white sand, well suited for the manufacture of glass. Preparations are in progress at present by the Catawba Valley Railway and Mining Companyy looking to the development of the Catawba valley sand deposits. A railroad is being graded between Salem and the Norfolk and Western Eailway and Catawba Mountain for the purpose of trans- porting the sand to Salem, where the glass plant will be located. Contract has been let for the building of the glass plant at a cost of $50,000.00.
An analysis of the Catawba valley sand, made by Mr. H. H. Hill, in the Laboratories of the Virginia Polytechnic Institute, gave :
Per cent.
Silica 96.99
Alumina .01
Iron oxide 02
Magnesia .07
Lime 80
Soda 1.40
Potash 20
Water and organic matter .31
Total 99.80
An exceptionally pure white sand is described by Professor Fontaine as occurring at the foot of the Potsdam mountains, a short distance southeast of Greenville, in Augusta county. The sand was pierced by a well which, after passing through 6 feet of blue clay, passed through 17 feet of Potsdam bowlders and sand. This sand is described as being of extreme whiteness, in large amount, and valuable for glass-making. A sample of moderately coarse and fine white sand, composed almost exclusively of
394 UINESAL BESOUBOSB OF TIROIHIA.
quartz grains, from the vicinity of Wayneeboro, gave on analysiE 98.5T per cent, of silica. Qlasa sand ia formed in a nnmber of other countiet, but the deposits have not received attention.
Holding Sand.
Molding Bands to be of valne must possess certain physical qualitiei, the principal ones of which are, according to Mason, elasticity, strength, and a certain degree of fineness. According to Ries, molding sand must be sufBciently fine-grained and aluminous to permit molding into the re- quired form; strong enough to hold its shape; resistant to heat, and porous enough to permit the escape of gases, hot noi admit the melted metiL An excess of clay and iron in the sands will cause the mold to Bbrinl: and crack under the intense heat, and too little will canse it to dry and crumble.
Sanda possessing the qualities enumerated above and of superior quality are found in the vicinity of Richmond, and at other localities a> the Coastal Plain or Tidewater region of Virginia, That found on the Gowardin place near Bichmond is of excellent quality and is ertensiTel; Qsed.
During his investigations of the Virginia Coastal Plain clays in the summer of 1905, Dr. Ries studied and collected samples of the tnoiding sand over the same area. The samples were analyzed in the laboratories of the Virginia Polytechnic Institute by J. R. Eoff, Jr., and James H. Gibboney, with the results given below. As indicated below these sands represent localities chiefly in the vicinity of Richmond, Petersburg, an<l Fredericksburg.
|
Percent. |
n Per cent. |
in Per cent. |
IV Per cnt. |
V Per cent. |
PercMil. |
|
|
8iHM (SiO,) |
81.59 6.46 4.94 0.14 0 22 MS 0.59 1.90 1.63 1.4S |
82. OS 7.12 4.63 0.3(i (1 3.5 1.28 0.41 0,30 t.66 1.52 |
C6,12 16.54 4.46 0.40 0,22 2.67 0,35 0.14 4.90 4.16 |
82,3a 7,80 3,98 0.54 0.41 1.64 o.so 0.22 0.19 0.14 |
70,24 16.62 |
70,4(1 3.80 |
|
Ironoxide(Fe,<>:,| Linie(DiO) M^5n«i»(MgO) Potoih (K,0) 8od> (Nb,0) TiUnicoiide(TiO,) W.t.r(H,0)... : WMer(inoUtu«) |
3.94 14.94 0.08 1 0.]] 0.09 1 0.15 1.41 I.9S 0.74 1 0.41 0.46 ; 0.70 4.16 4.0S 2.42 3-77 |
|||||
|
Toul |
100.12 |
99.71 |
99.95 |
98,04 |
100.16 1 100.3! |
lilSOELLANEOUS.
395
|
VII Per cent |
VIII Percent |
IX Per cent |
X Per cent |
XI Per cent |
|
|
Silict (SiO,) Alumina (A1.0,) Iron oxide (Fe,0,) |
84.40 7.56 2.52 0.06 0.21 1.29 0.65 0.44 1.99 1.76 |
93.92 3.22 1.08 0.24 0.08 0.45 0.23 0.32 0.48 0.18 |
85.04 5.90 3.18 0.06 0.14 1.65 0.83 0.78 1.57 1.11 |
86.24 6.32 2.44 0.34 0.10 1.38 1.13 0.02 2.94 1.29 |
89.39 5.94 1.22 |
|
Lime (CaO) Maffnesia (MffO) |
A. tttt 0.32 0.09 |
||||
|
Potagh(K,0) |
2.10 |
||||
|
Soda (Na,0) |
0 53 |
||||
|
Titanic oxide (TiO.) Water ( H,0) Water (moiatare) |
0.18 0.54 0.19 |
||||
|
Total |
100.88 |
100.20 |
100.26 |
102.20 |
100.50 |
I. Redford sand from foundry, Manchester, Virginia.
II. Redford yellow sand collected at pit, Manchester, Virginia.
III. Coarse sand, Harbaugh pit, Richmond, Virginia.
IV. Used molding sand, Redford pit, Manchester, Virginia. V. Sand from near Petersburg. Virginia.
VI. Blandford pit, Petersburg, Virginia.
VII. Armstrong pit, Petersburg, Virginia.
Vin. Sand from near Standard Brick Company, south of Suffolk, Virginia.
IX. Griffith's pit, Fredericksburg, Virginia.
X. Curlis pit, southeast of Lanexa, New Kent county, Virginia.
XI. One mile south of Layton, Essex county, Virginia.
The following physical tests made on the samples of sand from Vir- ginia, shown in the analyses above, by Doctor Heinrich Rie.^, further serve to show the general character of Virginia Coastal Plain molding sands :
Locality. 20
Redford yellow sand collected at pit
in Manchester, Virginia 1.51
Coarse sand, Harbaugh pit, Richmond 42.48
Used molding sand, Redford pit,
Richmond 5.34
Sand from near Petersburg 0.73
Blandford pit, Petersburg 3.03
Armstrong pit, Petersburg 0.09
Sand from near Standard Brick Com- pany, south of Suffolk 0.12
Griffith's pit, Fredericksburg 0.19
Curlis pit, southeast of Lanexa
One mile south of Lavton 6.68
|
ho |
QO |
80 |
100 |
lOOX |
Clay |
|
1.26 12.90 |
1.27 6.16 |
0.56 0.85 |
6.27 1.70 |
71.69 8.58 |
16.62 26.44 |
|
14.73 2.34 1.41 0.41 |
10.41 8.76 0.97 2.21 |
1.28 2.21 0.40 2.67 |
14.01 12.25 2.61 17.37 |
59.37 14.79 48.32 53.20 |
3.52 30.54 41.87 19.02 |
|
0.29 0.19 0.01 28.13 |
13.00 0.39 0.08 51.66 |
6.56 0.19 0.07 3.18 |
38.02 0.98 1. 11 3.75 |
35.1S 81.92 86.77 2.63 |
6.03 16.97 19.57 2.16 |
Building Sand.
A much larger amount of sand is consumed lor building and construc- tion work than for any other purpose. No special purity is required of a sand for this purpose, loamy sand as well as mixtures of coarse and fine
:i\)6
MINERAL RESOURCES OF VIROINIA.
sands as found in the banks being used. Usually when much coarse material is contained in the sand it is screened out before using the sand. Sand of the character described above and in all respects suitable for building purposes has wide distribution over nearly all parts of the State. It is found in considerable quantity along many of the stream courses in each of the larger divisions of the State.
Production.
Production of sand in Virginia by years for all purposes, for
190 Jf. and 1905,
|
Molding sand |
Engine sand |
Building sand |
Other purposes |
ToUl |
||||||
|
Year |
Short tons |
Value $ |
Short tons |
Value $ |
Short tons |
Value $ |
Short tons |
Value $ |
Short tons |
Viloe 1 |
|
1904 1905 |
64,313 : 30,943 61,246 j 37.899 |
3,600 4,775 |
1,800 3,580 |
267,264 244,572 |
123,842 96,248 |
4,357 5,272 |
3,482 3,400 |
339,534 160,067 315,866 141,127 |
3. MAxtliS. Definition and Properties.
As ordinarily used the term marl is applied to a variety of soft, earthy materials, composed principally of an amorphous form of carbonate of lime. The greensand marl is an exception, being a hydrous silicate of iron and potash. Marls vary much in color according to the amount and kind of impurities which they contain.
AVhen dry the purer forms are invariably of light color, white or cream. The impure forms are usually some shade of an intermediate or dark color. Moisture influences to some extent the color, for the same marl when dry has usually a lighter color than when wet. A marked feature of calcareous marls is their free effervescence in acids, which serves to distinguisli tliem from certain clays and muds which they sometimes re>einl;)le.
Origin and Occurrence.
Based on composition marls may be grouped into (a) calcareous or limy marls, and (b) glauconitic or greensand marls. Both classes have wide distribution over parts of Virginia.
The calcareous marls, sometimes known as shell marls, are chiefly formed in bodies of fresh water such as lakes and ponds, and about springs and small streams. They form a considerable part of the filling of many or
MISCELLANEOUS. 397
the extinct fresh water-bodies and are now forming on the bottom of many such bodies of fresh water. They are formed principally from the accumulations of the remains of fresh water algae, and from calcareous shells of lime-secreting animals. The stonewort ohara is an effective agent in abstracting the lime from solutions in lake water and forming lacus- trine marl. In some cases, as shown by Blatchley and Ashley from the lakes of northern Indiana, calcareous marls may be formed by chemical pre- cipitation.
Glauconitic or greensand marl derives its name from the presence of the green-colored mineral, glauconite, which is essentially a hydrous silicate of iron and potash, and which imparts a green color to the deposit. Ac- cording to Professor Wm. B. Clark, the mineral glauconite of the green- sand marls, occurs as grains which frequently show themselves to be casts of foraminifera and other calcareous organisms; and as pointed out by Murray and Renard it is always associated with terrigenous minerals, particularly orthoclase (feldspar) and muscovite (mica) and similar pot- ash-bearing minerals. The glauconite grains seldom exceed one millimeter in diameter but occasionally they are agglomerated into nodules of much larger size, the cementing substance of which may be phosphatic.
The glauconitic sands have wide distribution through the various geologic formations, and they are forming at present in places on the floors of existing seas, such as along certain parts off the Atlantic coast.
Distribution and Localities.
Marls of both calcareous and greensand tjrpes are widely distributed over the Coastal Plain or Tidewater region of Virginia. As early as 1835 Professor Rogers reported marls from the following Coastal Plain counties : Gloucester, Isle of Wight, James City, Lancaster, Middlesex, New Kent, Prince George, Surrey, and York. Since that time large deposits of marl have been noted in nearly all the remaining counties of this area.
Calcareous marls are also developed in places over parts of the Valley region west of the Blue Ridge.
The Coastal Plain Eeg^on.
Greensand marls. — So far as known this type of marl is limited to the Coastal Plain region, largely along its inner margin or western portion, where it is exposed along the Potomac, Rappahannock, Pamunkey, and James rivers. It is further found on the interstream areas and has been traced south from the James river almost as far as the State boundary.
o98 lilNKRAL RESOURCES OF VIROINIA.
According to Professors Rogers and Clark, the Virginia greensandfa and greensand marls are of Eocene age, and are found in the Pamunkey group, which in Virginia includes the Acquia and Nanjemoy formations. Professors Clark and Miller have described the Acquia formation as con- sisting of greensands and greensand marls, the latter often holding great quantities of molluscan shells that afford enough cement at times to pro- duce, under proper conditions, a hardened limestone. Likewise, the Nan- jemoy formation consists largely of greensands, but contains a larger amount of argillaceous or clayey materials. The combined thickness of these two formations, each measured in different places, is between 200 and 300 feet.
In some of the marl beds of this area the mineral particles of glan- conite are so abundant as to impart a pronounced green color to the de- posit. Specimens from James City, York, and other counties in the Cotstal Plain area, contain as much as 35 per cent, of the greensand or glauconite. The greensand marls are valuable for fertilizer from the amount of potash contained in them and at times for its additional phosphoric acid. Potash is very variable in amount in these marls, varjring according to the pro- portion of the mineral glauconite present, ranging usually from 1 per cent, in the very impure greensands to 8 and 10 per cent, and more in the purer greensands.
The following analyses made by EUett and Eskridge of the Virginia Experiment Station on samples of marl from Suffolk and Prince George counties, Virginia, serve to show the potash content:
Wavprly City Point City Point
Sussex Prince George Prince George County County County
Per cent. Per cent. Per cent.
Insoluble residue.. 45.20 61.15 56.03
Lime 24.38 1.36 1.52
Magnesia 5.22 2.19 0.37
Phosphoric acid. . . 1.80 0.47 0.06
Potash 4.73 3.85 3.15
Greensands are found further eastward in the Coastal Plain beneath the cover of Miocene and Recent strata, as exposed in the deep well at Fortress Monroe. The Virginia greensand marls have been worked to advantage at a number of places, especially on the James and PamuiJiey rivers.
Calcareous marls. — Marls of calcareous composition are extensively de- veloped over all parts of the Coastal Plain, being especially abundant in the Miocene and, in many places, hardly less abundant in the Eocene. The^e
MISCELLANEOUS.
399
have resulted chiefly from the accumulatioii of the remains of moUusks and other shell-secreting animals. In addition to their agricultural value, many of these marl beds are large enough and of suflBcient quality to be used in mixing for the manufacture of Portland cement.
In color these marls range from white to blue^ and are composed chiefly of calcareous matter, some with as much as 97 per cent., and gener- aUy the amount exceeds 80 per cent. Professor Sogers mentions particu- larly extensive beds of pulverulent white marl in Gloucester, New Kent, Prince George, and other counties. In a table given of the Miocene cal- careous marls from 9 localities in Gloucester county. Professor Rogers gives the percentage of calcium carbonate present as ranging from 37.1 to 96.8 per cent.; and 3 from New Kent county as ranging from 76.1 per cent, to 93.6 per cent. In places are beds of hard ferruginous marls consisting of shells more or less broken which are rich in calcareous matter; and shell-rock approaching limestone in composition, some of which Professor Rogers found to contain 87 per cent, of carbonate of lime.
At the Normal cliffs, on the Potomac river, shell marl has been dug for shipment and used in the manufacture of artificial fertilizers.
Ellett and Eskridge obtained the following results on analysis of marls from 9 counties in the Coastal Plain:
Insoluble Lime Magnesia Phosphoric Potash Locality. residue acid
Per cent. Per cent. Per cent. Per cent. Per cent.
Reves. Prince George Co 59.00 12.88 0.46 0.07 0.(53
City Point, Prince George Co. (57.69 20.41 0.35 0.33 0,41
Citv Point, Prince George Co. 70.61 12.75 0.09 0.17 0.34
City Point, Prince George Co. 28.07 38.15 0.42 0.29 0.60
Citv Point, Prince George Co. 41.71 27.40 0.06 0.38 0.26
City Point, Prince George Co, 47.26 24.44 0.48 1.50 0.27
City Point, Prince George Co. 39.05 27.96 0.84 0.13 1.02
Old Church, Hanover Co 45.68 21.73 1.10 0.16 0.45
Lumberton, Sussex Co 49.01) 25.90 0.06 0.18 0.43
Chuekatuck, Nansemond Co.. 13.70 40.97 0.23 5.36 0.26
Fort Lee, Henrico Co 16.80 26.79 0.45 0.03 0.25
Fort Lee, Henrico Co 29.23 35.74 0.66 0.77 0.65
Claremont, Surry Co 8.38 45.83 0.53 0.13 0.36
Yorktown. York Co 47.46 24.77 none 0.03 0.71
Roxbury, Charles City Co .. . 27.61 35.64 trace 1.24 0.20
The Valley Region.
Large deposits of marl, usually of good quality, are found in many of the Valley counties on the west side of the Blue Ridge. So far as the writer has information, the marls of this region belong entirely to the calcareous type. Some of these have formerly had a limited use as a flux in iron-making, and, in places, they may offer possibilities for use in the
400
MINERAL RESOURCES OF VIRGIKIA.
manufacture of Portland cement. See pages 159 and 160, under Cement and Cement Materials.
Ellett and Eskridge give the following analyses of marls from the Valley region:
Frederick Frederick Rockbridge Alleghany
County County County County
Per cent. Per cent. Per cent. Per cent.
Insoluble residue 2.61 3.65 4.34 6.91
Lime 52.62 62.19 47.87 60.58
Magnesia 0.43 0.44 3.24 0.86
Phosphoric acid 0.06 0.36 0.80 0.23
Potash 0.58 0.23 0.31 0.28
Uses.
The principal use made of marl is as a fertilizer and as an improver of the mechanical or physical condition of ceiiaiD types of soils. For these purposes its value is proportional, other things being equal, to the amount of phosphoric acid, potash, and lime it contains. The marl beds have been worked at numerous points in the Coastal Plain for local use as fertilizer. Marl is also used in the manufacture of Portland cement, m the manufacture of quicklime, and, in Virginia, it formerly had a limited use as a fluxing material in some of the iron furnaces.
Beferences.
Clark and Miller. A Brief Summary of the Geology of the Virginia
Coastal Plain. Virginia Geological Survey, Bulle- tin No. II, 1906, 12-24.
Darton, N. H. Geologic Atlas of the TJnited States. Nomini Folio
No. 23. U. S. Geological Survey, 1896.
Ellett and Eskridge. Virginia Marls. Bulletin, Virginia Agricultural
Experiment Station, 1897, VI (n. s.), 65-70.
Fontaine, W. M. The Artesian Well at Fort Monroe, Virginia. The
Virginias, 1882, III, 18-19.
Hotchkiss, Jed. The Resources of the Virginias On and Near the
Proposed Route of the Richmond and Southern Railway. The Virginias, 1880, I, 91.
Rogers, W. B. A Reprint of the Geology of the Virginias. Ne^
York, 1884, 28-49, 151, 156, 251, 419.
inSOELLANEOUS. 401
4. MILLSTONES (BTTHRSTONES).
Under this name is included a siliceous conglomerate of quite variable structure, used in the form of flat-circular disks for grinding purposes.
About 5 miles west of Blacksburg in the vicinity of Prices Fork, Montgomery county, a sandstone-conglomerate occurs in Brush Mountain, in which quarries have been opened for a distance of 3 miles. The stone is somewhat variable in color but is usually white or gray. Likewise, variation in the size of pebble is shown. The rock is made up of well rounded pebbles of quartz compactly embedded in a fine siliceous sand- stone matrix, the whole forming an exceedingly tough and hard mass. This stone is known on the market as '^rush Mountain*^ stone. Practically the same variation in the sizes of stone made at the different quarries obtains. The grindstones made from this rock are of excellent quality and they find a ready market. The age of the Brush Mountain stone is Mississippian (Lower Carboniferous) or Vespertine of Rogers.
Siliceous conglomerates similar to the above are found in the crys- talline area, east of the Blue Ridge, and are rather abundantly distributed over the Mountain district west of the Blue Ridge, but so far as the writer is aware the Brush Mountain quarries, in Montgomery county, are the only producing ones in the State.
Production.
The value of millstones (buhrstones) produced in Virginia from 1902 to 1905, inclusive, is as follows :
Year Value
1902 $11,435
1903 9,812
1904 4,769
1905 8,186
PART IV,
METALLIC MINERALS.
I. IBON.
BY B. J. HOLDEN.
Historical
The first iron ore mined in America of which there is any known record wafl mined in Virginia in 1609 by the Jamestown colonists. This ore was taken to England where it produced 16 tons of superior metal. The success of this experiment led to the erection of the first American iron works between the years 1619 and 1622 on Falling Creek about 1 miles south of the site of the present city of Richmond. These works were destroyed in the Indian massacre of 1622 before, they had been operated. For a century there were no further operations in the manufacture of iron.
The first successful iron industry in the South was established by Gor- trnor Spotswood in the pyrite area of Virginia. This was in connection with the Germania, or Rappahannock furnace, which was built about 1714, in Spottsylvania county, near the Rappahannock river. This was not only the first furnace in the South but, outside of New England and New Jersey, it was the first iron furnace in America. About 1727 (Jovernor Spotswood erected another furnace at Fredericksville, in the southwestern corner of Spottsylvania county. About the same time the Accokeek furnace was built by the Principio Company, on the land of Augustine Washington, the father of Greorge Washington, in Stafford county. Another pre-Revolutionary furnace was Old's furnace, near Charlottesville. The limestone limonite ores were early used by Miller's, or Mossy Creek furnace, built about 17G0, and by the Poplar Camp furnace, built in 1778, in Wythe county. The Oriskany ores wore probably first used by Zane's furnace, in Frederick county, in Revolutionary War time. By 1781 there were 3 furnaces in operation south of the James river in the magnetite area.
IBON. 403
In the iron industry transportation facilities are a controlling factor. The early furnaces of the pyrite area were within hauling distance of water transportation on the eastern rivers. Some of the early Valley furnaces operated to supply a local demand only. The furnaces of tho Shenandoah area, of which the Zane was the forerunner and which, in ihe period immediately preceding the Civil War, were leading producers of the State, had outlets in the northward flowing branches of the Potomac. To the early furnaces of the magnetite area, the James river was the highway of traffic. By the close of the 18th century the industry had been established on the James west of the Blue Eidge. By the middle of the 19th century the Oriskany district, located on the head waters of the James and dependent on that stream for an outlet for its product, had come to be the most important center of iron manufacture in the State, a position which it has since maintained. The coming of the rail- ways changed the conditions of iron manufacture. The effect was seen chiefly in three ways. These were, the large extension of the charcoal furnace industry in the 70s and 80s in Wythe county, the building of coke furnaces in the central part of the State in the SOs and, finally, in the shipment of iron ore. In the late 80s there was a great boom in the iron business in the State, which resulted in a period of most active furnace building. In the years 1890 to 1892 there were 10 coke furnaces built in the State, which became active just before the panic of 1893. In the 15 years since that time not a furnace has been built. The building of the Cripple Creek extension of the Norfolk and Western Railway in 1885 and, a decade later, of the Craig Valley Branch of the Chesapeake and Ohio Railway, opened two regions to shipment of iron ore which have since been important contributors to the iron ore production of the State. The recent construction of a branch of the Chesapeake and Ohio Railway south- westward from Covington up the valley of Pott's creek, and the projection of the extension of the Norfolk and Western Railway northeastward from Interior in the same valley, is expected to open up another important area to the shipment of iron ore. Recent discoveries in regard to the size of some of the Oriskany deposits and in regard to new modes of occurrence of this ore have led to larger ideas of the importance of this ore.
Iron Minerals and Ores.
Iron ores are considered commercially for statistical purposes in four classes. These are red hematite, brown hematite, magnetite, and carbonate. These commercial terms correspond roughly, respectively, to the minerals
404 MINERAL RESOUBOES OF VIBGIKIA.
hematite, limonite, magnetite, and siderite. There are other iron minerals from which iron is obtained as a by-product, the most important of which are franklinite, pyrite, and pyrrhotite.
Eed hematite corresponds to the mineral hematite (FcjO,), which carries 70 per cent, of metallic iron and 30 per cent, oxygen. This mineral is differentiated from the other iron minerals by its red streak or powder. Its specific gravity is 5.2. The mineral rarely takes on crystal form. The characteristics of the ore vary widely, especially in color and texture. There are three principal varieties, namely, red hematite proper, fossil ore, and specular ore. The red hematite is the most common, constituting the larger portion of the Lake Superior ores. In color it varies from red to brownish red, steel gray or even black. In texture, it is commonly fine-grained and varies in solidity from massive to powdeiy. The fossil ore is dark red to brownish red in color and is characterized by a fossiliferous or an o51itic structure. The specular ore is usually made up of flattened oval-shaped grains and is characterized by a black or steel gray color with a metallic pearly luster. It is the least important of the varieties of hematite. There are some similar metamorphic hematites that are sometimes classed with the specular ore. These are, the slate ore, which has a dark color and a slaty cleavage, and the micaceous hematite, which is even darker than the slate ore and readily cleaves into thin mica- like sheets. These hematites together include about 85 per cent, of the iron ore mined in the United States.
Brown hematite corresponds to the mineral limonite (2Fe2O,.3H,0), which carries 59.8 per cent, metallic iron, 25.7 per cent, oxygen, and 14.5 per cent, water. This mineral is distinguished from the other iron minerals by its yellowish brown streak. Its specific gravity is 3.8. It is never crystalline. The characteristics of the ore vary widely, especially in texture. It is usually massive, but may be powdery. As massive it is commonly porous, not infrequently vesicular, sometimes cavernous and stalactitic, rarely solid. In color it is brown, liver-colored to brownish yellow on the fractured surface, but frequently black and shining on the natural surfaces. Gothite (FcjOg.HjO) and other hydrous oxides carrying less water and more iron than limonite and commonly associated with that mineral are included under the commercial term brown hematite. Brown hematite constitutes about 8 per cent, of the iron ore now mined in the United States and is mined chiefly in Virginia and Alabama.
Magnetite corresponds to the mineral magnetite (Fe,04), which car- ries 72.4 per cent, metallic iron and 27.6 per cent, oxygen. This mineral is differentiated from the other minerals by its black streak and its mag-
IRON. 406
netic properties. Its specific gravity is 5.2. The ore is usually crystalline and commonly in small octahedral crystals, but may occur massive. In color it is black. Magnetite constitutes about 5 per cent, of the iron ore now mined in the United States.
Carbonate corresponds to the mineral siderite (FeCOg), which carries 48.2 per cent, metallic iron, 37.9 per cent, carbon dioxide, and 13.9 per cent, oxygen. This mineral is differentiated from other iron minerals by its effervescence with hot hydrochloric acid. Its specific gravity is 3.8. The ore rarely occurs in the form of the cleavable mineral siderite but as a fine-grained rock carrying more or less impurities. As such, its color is commonly gray, bluish gray or brown. When exposed to the air and mois- ture, it readily alters to limonite. Nearly all surface carbonate is consider- ably altered to limonite. The commercial term carbonate includes these altered products and the material so classed is commonly more limonite than carbonate. This is the least important of the ores of iron and con- stitutes less than 1 per cent, of the iron ore now mined in the United States.
Franklinite contains zinc and is mined for that metal in New Jersey. The iron left after the extraction of the zinc furnishes conBiderable of the former metal. The mineral has its crystal form, color and magnetic prop- erties similar to those of magnetite.
The sulphides of iron are extensively used in the manufacture of sulphu- ric acid. The iron by-product in this manufacture, known as purple ore or 'T>lue billy,'' is used in iron furnaces the same as iron ore. The most important of these sulphides are pjrrite and pyrrhotite. Both of these occur in Virginia and both are mined.
Pyrite, FeSa, disulphide of iron, contains theoretically 46.6 per cent, of iron and 53.4 per cent, of sulphur. It occurs frequently in crystals, which commonly have the form of cubes or pyritohedrons. Usually it occurs massive. In color it is quite uniformly a pale brass yellow.
Pyrrhotite, Fcn Sn+i, a sulphide of iron, contains a variable percentage of iron according to its variable composition. With the formula FcuSi, it carries 61.6 per cent, of iron and 38.4 per cent, of sulphur. It is rarely in crystals, usually massive with a granular texture. Its color is quite constant and is between a bronze yellow and a copper red. On fresh fracture it speedily tarnishes. It is commonly somewhat magnetic.
Impurities of Iron Ore.
The chief impurities of iron ore are silica, lime, alumina, phosphorus, sulphur, manganese and titaniimL
406 MINERAL RE80UB0E8 OF VIBGIKIA.
Of these silica, lime and alumina may occur in quantity but in the fur- nace are thrown into the dag. Phosphorus, sulphur, manganese and titanium usually occur in small quantity and in the furnace are eliminated from the iron not at all or only partially and with difficulty.
Silica in large quantity is objectionable in an ore, not only because it reduces the percentage of iron in the ore, but also because it reduces the production of the furnace by filling the furnace not only with silica but also with the lime which is necessary to flux out this silica. Ores canying as high as 40 per cent, silica are used in small quantity. In the limonite orea of the State the silica usually runs from 10 to 20 per cent.
Lime in small quantity is not objectionable. In large quantity it is objectionable only when present in amount greater than necessary to flux the silica present. Lime is not an associate of limonite ore but sometimes occurs in undesirably high percentages in the fossil hematite.
Alumina is a common associate of iron ores in small percentages. It is usually higher in limonite than in other classes of ores. In many limonite ores much alumina can be removed by washing. Alumina is apt to be ])articularly high in limonite ores that are associated with a shale residual, and much of this is so intimately mixed with the ore that it cannot be removed by washing. In large quantities alumina causes the furnace to work badly. It is usually present even in washed limonite ores to the amount of 1 or 2 per cent, and may run as high as 6 per cent.
Phosphorus is the controlling impurity which determines the use to which the iron made from the ore shall be put. Phosphorus of the ore goes into the pig iron. In minute quantities this element produces marked effects on both iron and steel. It renders iron and steel "cold short/' that is, brittle whi-n cold, but makes molten cast iron more fluid. For foundry iron, phosphorus is desirable in the ore in fractions of 1 per cent. Virginia cres are relatively high in phosphorus and this fact has been largely re- sponsible in determining that the State should produce foundry and basic iron. The limonite ores of the State usually carry from 0.1 to 0.4 per cent, phosphorus. It is an interesting fact that fault deposits are usudly high in phosphorus, even to the amount of 2 per cent, or more. Such ores are desirable for mixing with low phosphorus ores to regulate the phosphorus content of foundry iron.
Sulphur renders iron products ''hot short," that is, brittle when hot. even where present in small quantity. It is therefore objectionable. How- ever, the furnace coke usually carries so much sulphur that the sulphur ifl the average ore is negligible. Sulphur is apt to occur in ore as pyrite but
IBON. 407
in some limonites it occurs as gypsum or barite. When present in small fractions of 1 per cent, sulphur may be neglected.
Manganese usually occurs in iron ores in fractions of 1 per cent. In certain limonite ores it occurs to the amount of several per cent. Limonite ores are now mined in Virginia which carry 6 per cent, manganese. It also occurs in such quantity that the iron is subordinate in amount and the ore is a manganese ore. Manganese is not usually objectionable in fractions of 1 per cent. For the manufacture of foundry iron the Virginia limonites have to be selected that they may not carry too high manganese content. The ores high in manganese are used for basic iron.
Titanium is objectionable in that it interferes with the operation of the furnace. According to Virginia blast furnace practice, when titanium dioxide is present in quantities greater than 1 per cent, it makes the ore objectionable for furnace use. Titanium occurs chiefly in magnetites.
Origin of Iron Ore.
Iron ore originates for the most part by the segregation of iron, leached from rocks relatively lean in that element. The iron is carried in solution by circulating surface or ground waters and eventually precipitated. The precipitation may occur in some body of standing water and the deposit be a bedded deposit analogous to other bedded deposits, or the precipitation may occur on or near the surface of the land. Deposits beneath the land surface may be in cavities or may be replacements of the rock. In either case limestone is apt to be an associate of the ore deposit. This is true in the first case because limestone is one of the most soluble of rocks and therefore one of the most cavernous. In the second case it is true because the lime readily acts chemically upon the iron in solution in such way that the iron of the solution and the lime of the limestone exchange places. In Virginia examples of bedded deposits are seen in the fossil ores of the Alleghany mountains and the hematite of the Blue Ridge, and examples of land depos- its are seen in the Oriskany ores. The different kinds of ores and ore minerals may be the result either of original differences in the minerals which arose at the time of the precipitation of the iron from solution, or of subsequent alterations from one form of minerals to another as a result of geological processes.
Classification of Virginia Ores.
The iron ores of Virginia may be grouped according to their character and occurrence into eleven classes. Listed roughly in the order of their im- portance these are as follows: Oriskany limonite, limestone limonite. Blue
408 MINERAL RESOURCES OF VIROIKIA.
Ridge limonite, fossil hematite, Blue Ridge hematite, pyrite gossan, pyrrho- tite gossan, Piedmont magnetite and specular hematite, limestone magnetite, pyrrhotite and titaniferous magnetite. Of these the first five include most of the iron ore now mined in the State. The remainder are mined at present either from only one or two mines, or are of historical importance only, or are of possible future importance.
Oriskany Ore.
The name Oriskany was given to the limonite ore which was formerly supposed to occupy the position of the Oriskany sandstone. The name is here used for those ores to which it was originally applied and also to all other ores which have a similar origin and occur either in the Helderberg, the Oriskany, or the lower part of the Devonian shale.
This ore is the most important of the classes designated above. It was much mined for charcoal furnaces before the Civil War, and is now exten- sively mined in the Oriskany area. It is found in the Alleghany mountains from one end of the State to the other. It occurs most abundantly in the Oriskany area, chiefly in the counties of Alleghany, Botetourt and Craig. It has been considerably mined in the Great North Mountain area, chiefly in Shenandoah county. Here the ore occurs chiefly in the Devonian shale. It has been mined to a less extent in Massanutten and Draper mountains and also, in a small way, in a number of other localities.
Most of this ore occupies a very definite horizon at the top of the Helder- berg. It occurs in subordinate importance in the lower part of the Devon- ian shale and rarely in the Oriskany. The strata which are associated with the ore, as they usually occur near mines, taken in descending order, may be listed as follows:
Devonian 300+ feet. Shale, black at the bottom.
Oriskany 0—15 feet. Calcareous sandstones.
r 10 — 60 feet. Pure thick bedded, soft, fossil if erous limestone. Helderberg <
[ 20 — 60 feet. Cherty limestone.
The ore is found characteristically replacing the upper pure limestone of the Helderberg. In some localities it is found at varying horizons near the base of the Devonian shale. Rarely the Oriskany sandstone is ore- bearing. Underneath the Helderberg chert there may be several ecoic feet of limestone, shaly limestone and sandstone. These latter present considerable variation in different localities. The lower measures have no significance so far as the iron ore is concerned, as there is not a singk instance, known to the writer, in which ore is found below the main body
of the chert. Underneath the Helder- berg there ie a thickness of aboat 50U feet of Clinton and Medina which is mainly quartzite. The qnartzite of these horizons is the ridge maker of the Alleghany mountains. Where the mountains are anticlinal, as in the Oriskany area, the ore-bearing rocks appear on the lower slopes on both sides of the mountain and in the Talleys.
The iron of these ores was originally disseminated in the Devonian shale. As this shale was eroded the iron was taken in solution, carried down and deposited in any favorable place. Ordinarily this place was the upper portion of the Helderbeig limestone In some cases there was a direct re- placement of the limestone by the iron and in other cases the iron was de- posited in the space from vhich the limestone had been removed by solu tion. The iron rarely occurs in the sandstone in minable quantity. In the shale it has been deposited chiefly parallel to the bedding of steeply in dined strata.
The outcrop of the ore is usually found on the lower slopes of the mountain a few hundred feet above the valley botton. (See figure 66.) Along the base of the mountain on the strike of the formation the ore may appear with more or less development for miles. Continnons ore-bodies with fairly constant thickness have been worked for half a mile. The thickness of any ore-body has been largely con- trolled by the original thickness of the upper layer of the limestone at that
410 KIKEBAL BESOUBOBS OF YIBQINIA.
point. Usually this is replaced to its full width, where replaced at all, and it rarely occurs in thicknesses of a few feet. From 8 to 35 feet are usnal thicknesses of the ore-body. Smaller thicknesses are not common except on the borders of the ore-body. Greater thicknesses are not unknown. On the slope of the mountain, that is on the dip of the formation, the extent of the ore-bodies varies between wide limits. The outcrop may be a mere pocket or the ore may extend 700 feet on the slope from the outcrop. Where the outcrop of the limestone horizon is not ore-bearing, ore may occur lower down, generally on a sharp fold of the strata. In some instances there are a number of folds which occupy the lower slopes of the mountains on opposite sides of the valley and the valley between. These may be wholly or partly f?Jled with ore on both trough and crest.
The ore is commonly a continuous mass filling the space, and not lumps of ore in clay. The ore occupies the position in which it was deposited from solution and has the form which it then assumed. It has not been deformed or fractured since it was deposited. The mass is not solid but porous or cavernous. The cavities vary in size from a fraction of an inch up to a foot or more in diameter. These cavities may be vacant but commonly contain water, clay or sand. Less commonly the clay is more abundant and the ore is distributed in it as nodules, irr^ular masses and stringers. Rarely the associated material is loose sand and the ore consists of stringers in the sand. Where the ore is associated with the shale it may exist either as a surface pocket or as a concentration at some lower depth above an impervious basement or as stringers dipping at high angles with the bedding of the shale. This last occurrence is the most important of the shale occurrences. In this case the stringers may have widths of from a few inches up to 15 feet or more and extend downward 50 to 100 feet. The ore is washed in log washers to remove the clay and not nn- comraonly is jigged to remove sand and flint. From 50 to 80 per cent, of the material mined is delivered from the washer as washed ore.
The average composition of the Oriskany ores as mined, computed from
available analyses, is as follows:
Per cent.
Metallic iron 43.25
Silica 21.57
Phosphorus 0.38
Manganese 1.29
Limestone Limonite Ores.
The term limestone limonite is here applied to those limonite ores which are associated with the residual decay of a limestone. These ores consist,
411
for the most part, of ^ains and lumps of limonite scattered through the limestone clay. Such ores are locally known as "limonite." Where limonite ore is more massive and in sheets or larger masses and usually associated with shale, shale residual or other relativelj- impervious material, the ore ifl locally known as "mountain ore" to distinguish it from the softer, more porous and usually higher-grade "limonite." The term "mountain ore" woold apply tfl any brown hematite ore which was not the so-called "limon- ite." The term limestone limonite includes the so-called "limonite" and 8Qch of the "mountain ores" as have been obviously inherited from a lime- stone residual.
4
These ores are well adapted to use in charcoal fumacea and have been mined for that purpose for 150 years. They are now only second m impor- tance to the Oriskany ores and are extensiyely mined The chief occur- r^ce of this ore in the State is in the New River-Cnpple Creek area It has been mined most extensively in the countiea of Wythe and Pulaski. This is the ore which occurs near the base of the Shenandoah limestone. There are a few other isolated occurrences of the ore of this honzon in the Valley near the Blue Bidge. The ore of the upper honzon of this limestone is nowhere sufficiently developed to form a mining area of consequence but occurs in minable quantity in a number of scattered localities throughout the Valley, particularly in the northern part.
These ores are associated with the Shenandoah limestone and are known with the Greenbrier limestone. The diief occurrence is with the lowest
413 UINERAL REBODKCES OF VIRGINIA.
members of the Shenandoah limestone. In the New River-Cripple Cred area where this ore has its greatest development, the lower portion of the Shenandoah limestone is a pure limestone through a thickness of seTeral hundred feet. Under the limestone there is a thin shale and under this i consideraiile thickness of quartzite. These strata have been deformed con- sidorabl}' by folding uud some by faulting. Along the southeast side of tlie Valley and along several anticlinal valley ridges and other valley anticlinala, the upper limestone measures have been removed by erosion and the bwra measures outcrop along the base of the slopes and the crests of the non- ridge-making antielinals. WTiore these measures outcrop the residual cisT above the limestone is usually ore-bearing. In this area the New rira and its branches have cut down 200 to 300 feet below the general ierel of the limestone surface. The land surface presents a series of oval domes
Fijt 58 — Diagram lUuBtrating rPlatmna of thp hindnite id the New River Cripple Cr^ek area to the lo\«er iiieaBureii of the bhenandoali limeatoiw. Black cover represents ore bearing clay Upper measures are Sheirn doah limestone Thin lined measures under ^benandosh are Cambnu shales The mountains are Cambrian sHUdstonefl and Bh&lea
and the ore la found mostly on the crests and upper slopes of these hills, several hundred feet above the major streams. Another occurrence of this ore aside from that at the base of the Shenandoah limestone is thst which occasionally appears near the top of the same limestone. This on occurs in widely scattered areas in different parts of the State so that it ii not possible to closely correlate the horizons. These occurrences of ore are quite unifonnly associated with limestone phases which have a remark- able devdopraent of chert. The chert is commonly ridge- or knoU-forming and the ore occurs in the limestone residual on one side of the hill.
The iron of most limefltooe limonite ores was originally diseenunated is the limestone. The ore arose by the removal of great thicknesses of the limestone by solation and the segregation of this iron in the residnil cIa; above the limestone. The final concentration of the iron in the dtj wu broa^t about largely by the solution of the iron near the surface of &• digr nid- H» depoaitum lower down. In some cases running water is
IBON. 413
rink holes, acting as a great natural washer, further concentrated the lamps of ore.
The weathering of the limestone hag left behind the more inaolnble portions of the rock, the clay, which covers the present rock surface to depths which vaiy from a few feet up to 80 feet. The limestone weathers very irregnlarly. (Figure 59.) Commonly these irregularities take the form of pinnacles or steep domes, varying from those which are slender and closely spaced to the larger ones 25 feet in diameter and 50 feet high. (Plate LXXVIII, figure 2.) The clay with the 'Himonite" ore lies between end over these "horses," forming a cover over their tops which may be 20 feet thick. (Plate LXXVI, figure 2.) The ore occurs at various depths
in the ctay. The upper few feet of clay are usually barren. The best con- centration nsnallj occurs at depths of from 10 to 20 feet. However, ore may occur well to the bottom of the deep clay. The ore is scattered through (he day in pieces which vary in size from lumps a foot in diameter down to floe particles. The greater portion of the ore is in the smaller size pieces and sometimes is merely a coarse grit in the clay. Where the masses ■re more than a few inches in diameter they are usually porous with clay in the cavities. The percentage of ore in the clay varies between wide limito. At lis beet concentration in bodies of any size the ore constitutes ■bmit 30 -per cent, of the total material of the bank. Where there is less than 4 per cent it is not nstially minable. The clay sometimes carries minable percentages of ore over continuous tracts of many acres. Where &e itoa has been deposited above a basement which is relatively impervious to water each as is famished by the shale and quartzite underlying the limestone, the ore is more massive and usually constitutes a mnch larger
414
MINERAL RESOURCES OF VIRQINIA*
percentage of the bank. In such cases the ore is usually in thin seams or lumps, but may constitute masses of 1,000 tons weight. These "moimt&iii ores'* are commonly of a lower grade than the *^imonite.'^ Along the contact of the limestone and the sandstone there are ores which have characteristics of both the ^limonites*' and the "mountain ores'* and are known as "semi-limonites.**
The average composition of these ores is shown in the following table, which is compiled from analyses furnished by the Virginia Iron, Coal and Coke Company, the Pulaski Iron Company, and the New Biver Mineral Company.
Analyses of iron ores from the New River-Cripple Creek district:
Limonites^ Semi-limonites' Mountain ores* Ayerage^
Per cent. Per cent. Per cent. Per cent
MeUllic iron 43.76 40.72 37.86 41.M
Silica 13.52 20.12 18.60 16.17
Alumina 1.79 1.81 2.32 1.91
Phosphorus 0.17 0.31 0.40 0.25
Manganese 0.68 0.S3 1.40 0.81
(^) Average of 56 analyses from 12 mines.
(') Average of 15 analyses from 5 mines.
(') Average of 17 analyses from 4 mines.
{*) Average of all ores from 21 mines.
Blue Bidge Limonite Ore.
This term is used to include all the limonite ore which occurs in the vicinity of the Blue Ridge. Of these there are two classes, the ores which are in the shale and sandstone chiefly at the west base of the Blue Ridge, and the fault deposits chiefly in the sandstone.
This ore was considerably mined for charcoal furnaces and is now mined for shipment at half a dozen operations. '^These ores occur along the Blue Ridge and have been mined at frequent intervals from Roanoke to Front Royal, a distance of 150 miles. At present the most important operations are in the vicinity of Roanoke, Buena Vista, and Front Royal. Most of the ore thus far mined has come from the west slope of the mountain. Several mines have been located on the east slope of the main western ridge. Portions of the Blue Ridge have a complicated structure and its surface consists of a series of peaks and valleys over areas which are locally 12 miles wide. Some of these areas are known to contain ore but the obstacles to transportation are so great that little has been mined. In parts of the Blue Ridge the strata underlying the Valley limestone are sandstones and not favorable for the formation of ore. In other places,
IBON. 416
particnlarlj in the southwest, the measures which might bear ore are buried b; faulting.
The surface rock of much of the Blue Bidge is composed of two main members of probable Cambrian age, the sandstone and the overlying shale. The Blue Bidge is in general an anticlinal mountain from the crest of which the shales have been eroded. The crest of the mountain is then composed of the sandstone while the shale appears on the flanks. On the west side the ehale at the base of the mountain dips northwest at hi^ angles. It is in this that the shale ore of the first kind is found. The fanlt deposits are higher up on the mountain in the sandstone.
The iron which is now in the ore is believed to have been leached from the shale, carried down and deposited in any favorable place. This applies to all the limonites of the Blue Ridge. Tn the case of the shale ores it ia certain in some, and probable in most cases, that the ore was deposited In
e Riil^'c linionite
association with limestone. The ore either replaces the limestone or was deposited in the space from which the limestone had been removi'<l by solution.
On the wost side of the moiintnin the shale commonly forms a bench which is a few hundred feet above the limestone of the Valley and which has a width of a quarter to a half mile. Ft is in this bench that the shale ore usually occurs. Characteristically the ore-bodies dip north at high angles with the bedding of the shale. The width of Ihe ore-body is quite variable even in short distances, ranging from the thinnest minablc seam to a thickness of a score or two feet. The length of the deposits as continuous bodies is quite limited. The greatest known length of con- tinuous working is about a quarter of a mile. The greatest depth to which ore has been mined is about 200 feet. The fault deposits occupy a position along the fault plane of a well marked fault line or are a series of deposits along a general fault and breccia zone. The direction of the fault may he either parallel or transverse to the strike of the bedding. In
416 MINERAL BESOUBCES OF YIBOINIA.
the case of the deposit along a well marked fault line there may be thicknesses up to 20 feet. The other sandstone deposits are irregular and have a variety of occurrences, but in general they are more compact and have less linear dimensions than the shale ores.
The shale ore, where it occurs in large bodies and is an evident replace- ment of the limestone, has the same open porous texture characteristic of the Oriskany limestone ore. Where the ore-bodies are thin the ore is apt to be in compact masses of stringers in the decomposed shale. Where the ore is still less abundant it is in the form of lumps, grains and stringers intimately associated with the shale usually in more or less ferruginated beds. The fault deposits are compact black masses of limonite ore. In some instances they have been fractured by dynamic movements subsequent to their deposition. These fault ores are comparatively free from clay and are sent to the furnace as mined without washing. The other sandstone ores may be sandstones which have become highly impregnated with iron or masses of compact massive high grade ore. The composition of the shale ore will vary widely according to the way it is mined. There is much good ore intimately associated with clay that is difficult to mine^ without including considerable low grade ore that is difficult to separate from the better ore. The fault deposits are characterized by a high phos- phorus content.
The average composition of the Blue Ridge limonite ore as nuned, computed from available analyses, is as follows:
Per cent.
MeUllic iron 41.22
Silica 20.61
Phosphorus 0.93
Manganese 0.00
Fossil Hematite.
Fossil hematite is a hematite ore, which occurs as a bedded deposii It occurs abundantly in the Appalachian mountains and is mined from New York to Alabama. Westward in the flat-lying strata it is mined in Kentucky and Wisconsin. This ore is variously known as fossil, oolitic, Clinton, Bockwood, and dyestone.
This ore was little used in charcoal furnaces. It was first mined for shipment in this State about 1880, It is now mined at Low Moor in the Oriskany area and in a number of operations in the fossil hematite area.
These ores occur in the Clinton stage of the Silurian rocks. The Clinton rocks of Virginia present considerable variation in kind and
IKON. 417
thickness in different localities. In general they are sandstones or quartx- ites and shales with a few thin beds of limestone^ having a total thickness of from 100 to 900 feet and an average of about 400 feet. Except in the extreme southwestern part of the State, the upper member of the series is a white quartzite while the lower members are mainly thin sandstones, sandy shales, shales, and iron ore. The ore usually occurs interbedded with shale. The Medina rocks underlying the Clinton are usually thick bedded sandstones. These rocks, together with the Clinton, are the main mountain- making strata of the Appalachian mountains in Virginia. As a result of this the fossil ores usually occur well up on the slopes of the mountains. In the Oriskany area the mountains carrying fossil ores are anticlinal and the ores outcrop near the crest of the mountains and dip on both slopes. In the fossil ore area the ore-bearing mountains carry less sandstone measures and are in consequence not so high and, in addition, are mostly monodinal with the ore beds dipping in one direction. In the Oriskany area one minable bed is known. In the fossil ore area there are three beds which have been mined. These beds have been designated numerically from the lowest up as Nos. 2, 3, and 4. The beds are rarely all workable in the same locality. No. 3 lies stratigraphically above No. 2 from 176 to 226 feet, and No. 4 lies 80 to 90 feet above No. 3. No. 3 has been mined the most extensively and No. 2 the least.
These ore-beds are mined at a minimum thickness of 16 inches and have a maximum thickness of something over 4 feet. Usual thicknesses are from 22 to 36 inches. In minute structure the ore occurs in two main forms, the fossiliferous and the oolitic. In the fossiliferous variety the ore pari:icles consist of small fossils and fossil fragments which have had their calcium carbonate replaced by iron oxide. In the oolitic variety the iron oxide is in the form of concentric layers about some central particle, which is usually a grain of sand or a fossil fragment. In its original condition these concretions and ferruginated fossils were associated with considerable calcium carbonate. Where the lime constituted a considerable percentage of the total material, the rock was a limestone which was thickly set with these iron particles. Where the ore is now above the level of the ground water most of the lime has been leached out. Such leached ore is known as soft ore while the unleached or limy ore is known as hard ore. Up to the present time very little hard ore has been mined in this State. The soft ores of the fossil ore area carry 35 to 45 per cent, of metallic iron and from 15 to 35 per cent, of silica. On the lower levels they are apt to be limy and may cRTry lime up to 14 per cent. The soft fossil ores of the Oriskany area are of somewhat higher grade carrying about 45 per cent.
418 MINERAL RESOURCES OF VIRGIKIA.
of metallic iron. The hard ores oflFer possiblilities which have not yet been nsed. Such ores may carry 35 to 55 per cent, calcium carbonate and only 25 per cent, of metallic iron and, if the silica is low, still be usable.
The average composition of the fossil ore as mined in Virginia, com- puted from available analyses, is as follows:
Per cent.
Metallic iron 40.84
Silica 21.70
Phosphorus 0.36
Manganese 0.15
Blue Bidge Hematite.
This ore is locally known as specular ore. As the name specular has been applied to a granular black metamorphic hematite, the term specular as applied to this ore is misleading, as it has none of the distincti?e characteristics which the specular ore has. This ore was not used in charcoal furnaces. It was first mined for coke furnaces about 1880. It is now mined in a number of operations between Roanoke and Buchanan.
The Blue Ridge hematite ore occupies a definite stratigraphic position in the (topographically) upper end of the great shale formation. It has not yet been definitely determined whether this shale is Cambrian or Ordovician, but it has formerly been regarded as Cambrian. The outcrop of the ore occurs well up on the mountain some 500 to 1,000 feet abo?e the valley. On the Buchanan end the outcrop is on the northwest side of the mountain while farther southwest, near the Grubb mine, it is on the southeast side. The shale enclosing the ore has been intricately folded and portions of the ore-bearing strata occur a quarter of a mile down the mountain from the normal position.
This ore is a bedded deposit, which was formed as a water deposited sediment and later compacted and elevated to its present position, in the same manner as the other associated sedimentary rocks.
The ore bed has been much deformed both by folding and faulting. This has in places resulted in the production of several parallel outcrope. In the view on plate LXVI, figure 1, two of these parallel outcropB are shown. This deformation has altered materially the original thickness of the bed. Where the normal thickness was 3 to 6 feet the limbs of the folds may be thinned to 18 inches or even entirely disappear, while the crests of the folds may be thickened to 12 or 16 feet. The ore-bodies usually dip at high angles. On the strike the ore-bodies are persistent for miles. Surface in^dngs are interrupted by ravines, but with depth they will doubtless
J
noK. 419
be ocNDtmuous orer long dist^Dces. On the dip the ore has been mined tc a depth of a couple hundred feet. The ore probably ext^ids to as great dapths as it will erer paj to mine.
The ore is a massire bed of siliceous hematite bettre^i walls of shale. It is considerablv fractured; loeallT, so much so that the ore is removed bj djnamite which is inserted in crerices without drilling and the ore remoTed in angular blocks. The silica is largely present as quartz graina.
The ore carries in metallic iron from 35 to 42 per cent., in silica 20 to 38 per cent, and less than a half of 1 per cent, each of phosphorus and
The ore is well known at intervals in the counties of Boanoke, Bedfnd, mod Botetourt along a distance of 30 miles. It has been considerably mined near Blue Ridge Springs, and near Buchanan. It is reported to mppexr at Buena Vista as a ferruginous sandstone and to have been mined near Basic Citv, 60 miles northeast of Buchanan.
The average composition of the Blue Bidge hematite as mined, oom-
pated from available analyses, is as follows:
Per eeuL
Metallic iron 38 94
Silica 33.26
PhosphoruB 0 38
Manganese 0.22
Pyrite Gossan.
Fjrrite gossan is a limonite which is formed by the oxidation of pyrite. I^jrrite is widely distributed east of the Blue Ridge in the main pyrite area, as shown on map, figure 64. It occurs as definite leads and as more or less thickly disseminated pyrite in the schistose rocks. P}Tite is now iprorked in Ix)uisa county and is used in the manufacture of sulphuric acid. The **blue billy," which arises as a by-product in the manufacture of the add, is sometimes smelted for its iron. The outcrop of the pyrite is everywhere altered to limonite. This ore was the basis of the first iron industry in Virginia and for 150 years was mined for charcoal furnaces. Hxcept in one or two instances the ore has not been mined by modem methods for shipment.
i
Pyrrhotite Gossan and Pyrrhotite.
Pyrrhotite gossan is limonite which is formed by the oxidation of pyrrhotite, a sulphide of iron. The pyrrhotite, together with its associated minerals, chiefly chalcopyrite, talc, calcite, hornblende, and quartz, consti-
420
MIHEBAL B280DR0E8 OF 7IB0IKU.
tnting the vein filling, is locally known as "mundic." This gossan wu need in bloomery forges and charcoal furnaces for 75 years. It was not satisfactory for wrought iron, but was uBed Buccesafnlly for castings. In the two places where the main lead has been reached by railway tran^ portation the gossan has been extensively mined.
These ores occur in Ashe and Alleghany counties. North Carolini, Grayson, Carroll, Floyd, and Franklin counties, Virginia. In the eoutb- westem part of the State the Blue Ridge divides into two ranges. Tbe
Fig. 61. — Diagrammatic cross section of the "Great GoBSan Lead" in southwest Virgiuia, abowing relatiuna of altered and unaltered pjirhotite to tatb other and to the encloaing achiats (a) Crjatalhna scbista. [b) Pyrrho- tite ("wundie"). (o) Copper ('smut") ore — aecoiidary concentration.
area between these ranges, including the counties of Floyd, Carroll, and Qrayson, constitutes a plateau which nses above the Vall^ on the north- west and the Piedmont on the southeast The pyrrhotite leads occur in this plateau and have their etrongeat development in the northern part ot Carroll county, a few miles from and parallel with the northwestern border range. The rocks of this area are of doubtful age Quite nniformly th^ lie mica schists with the schistosity dipping to the southeast.
The pyrrhotite occurs in isolated areas and in more or less regulu leads. The leads dip on tbe average about 35° to the southeast with tlie ■dtifltosity. The width of the lead is quite variable. It may pisch ont
IBOK. 421
entirely or have widths as great as 175 feet. Through several hundred yards it may hold a quite constant width of from 10 to 20 feet. For several miles at a stretch it may be fairly continuous and workable. The average width as measured at 18 places where mined for copper is 27 feet with extremes of 6 and 60 feet. Its depth has been proved in two places to be several hundred feet and its probable depth is several times this. The surface of the lead is everywhere weathered. As measured in 20 copper operations this weathering has extended to an average depth of 34 feet, with extremes of 10 and 60 feet. This weathering has produced an oxidation of the sulphides and a removal of some of the material, particu- larly iron and copper. Further description of this lead as a copper producer is given under Copper on pages 511-517. About one-half of the original material has been oxidized in position to a porous limonite. This is ike gossan. In two places the pyrrhotite has been mined for its sulphur content. The 'T)lue billy/' which results when pyrrhotite is used in the manufacture of sulphuric acid, has been used to a small extent in iron furnaces as an ore. If a process shall be developed whereby the sulphur is successfully eliminated from this material, this pyrrhotite lead will be one of the greatest deposits of iron ore in the State.
Piedmont Magnetites.
Magnetite occurs in the southern part of the State east of the Blue Ridge among the crystalline schists of the Piedmont. It occurs in three districts along the same general line with somewhat different charac- teristics in each district. In Franklin and Patrick counties it occurs in leads which are said to attain a width of 12 feet and which are associated with a hornblende schist, the ore-body dipping with the schistosity. This ore was mined for early charcoal furnaces and has since been mined for shipment. In Grayson county there are a number of occurrences of magnetite which are better known on the North Carolina side of the State line. In Pittsylvania county occurs the most extensively mined magnetite. It occurs between walls of crystalline limestone and mica schist in thicknesses up to 12 feet. This was not mined for charcoal furnaces but has been mined for shipment pretty constantly since 1880. On the James river, some 12 miles below Lynchburg, is a magnetite area which in Jefferson's time was a leading iron producing area of the State. About 1880 this region was exploited and some ore shipped. Most of the workings are now closed and little is to be seen of the ore-bodies. Mining was done by open cut and by shaft and tunnel to depths under 200 feet.
422 MINERAL RESOUBOES OF VIRQINIA.
The ore is magnetite and specular hematite with limonite in the vicinity, but not usually in immediate association. The associated rocks are chiefly metamorphosed sedimentaries, quartzite^ mica and talc schists, and lime- stone. There are a few scattered trap dikes. In some instances the iron schist overlies quartzite and follows the bedding and is locally an ore. One mine is reported to have produced 10,000 tons of ore. Some of the ore carries phosphorus below the Bessemer limit.
Limestone Magnetite.
Limestone magnetite is the name given to the magnetite and associated iron ores which occur in the Shenandoah limestone. With the magnetite there is associated hematite, limonite, and iron carbonate.
This ore occurs in Giles and Washington counties. It is a secondary deposit in the limestone. In the case of the Washington county deposits the ore is at the extreme top of the Shenandoah limestone and located near the border of an area of Athens shale. The iron of the ore was leached from the shale and deposited in its present position. The magne- tite is usually found farther from the surface than the other minerals. In the limestone about these ores in some instances there is iron carbonate which at the surface has been altered to limonite. In some instances the limestone about such deposits has been removed by solution, and lumps of magnetite of a few pounds weight are now found scattered through tiie clay. About a half dozen of these deposits have been worked. As thus far developed they are small, a few rods wide by 30 feet deep, but with indications on the surface for many rods. Two small mines were operated in 1906, Where the ore is well concentrated the magnetite is the highest grade ore in the State and usually has its phosphorus below the Bessemer limit.
TitaniferoTis Magnetite.
Titaniferous magnetite occurs in Virginia in several different assodft- tions. By present furnace practice it is not usable as an iron ore but offers possibilities for the future. It occurs in the Blue Ridge in a distinct lead which has been prospected in one place and which is reported from a number of places. Near Roseland, Nelson county, and near Vinton, Roanoke county, it has a very different occurrence. The titaniferous rock h made up chiefly of small grains of apatite and ilmenite. It is reported to exist in considerable quantity. These occurrences are described in some
HOOT. 4IS
denil OB pa^cs ^S2 axsd ^X^-^1. In GniTsciii tcoantr pitej^Ktinir Itis profod dup pTcscsaoe A>f a manif eixms magaedte kiid viikii b beniH' faaovB in ihc «OQti£TK>=Q^ oocniks of Xcffth CmroliiML
Iitm ore is ?s?oc:a:^ with the rock> of rarocs ii?wJv>co*l Ajc«i in die State of Ylrsmii- I: w>:ur5 most abunoantlv in :he str^itai which ai^ at the top of the Sil^irian and near the base of the DeTic^ian. It oiN*ur» somewhat !e9s abuDdantlj in the rock? of the middle C^tmbrian a$e. In other words it ocoir? near the center and near the ba^^e of the seolorical column, as this is shown in the no^hwe^tem half of the State. Of these <Hres two classes, xhe fossil hematite and the Blue Rids?? hematite, an? of the same age as the enclosing rocks. All others originatevi later than the rocks enclosing them. However, for the pnrpos*e of distinguishing a ela» of ore, the name of the enclosing rock may be used.
The crrstalline rocks of the Piedmont, whose age is doubtful, oarrr flcnne ores of magnetite, specular hematite, and limonite. Beginning with the oldest rocks of definitely knoftn age with which iron ores atv known to occur, iron ore occurs at several horizons in the Cambrian. A small amount of magnetic ore occurs with the Unicoi samisione. Ijmonite occurs in small quantity with the shale above this samlstoue. This latter is of commercial importance in Tennessee and may be of importanc^^ in Virginia. The Blue Ridge hematite, a bedded deposit, occurs in strata which have been considered Cambrian. The age of these rocks has not been satisfactorily determined, and there is a possibility that thev may be the shales of Rogers' Xo. III. In the upper Cambrian sandstone ther? are fault and other deposits of commercial inipiirtaniw Of these, the fault deposits are now being mined. In the Cambrian shales above the upper sandstone are limonites which are now being mincil at several operations. In the lower portion of the Valley limestone which is considered of Cam- brian age are limonites of the finest quality and of such quantity as to rank second in importance among the ores of the State. In higher portions of this same limestone there are scattered deposits of some commercial importance which are presumably of Ordovician age. The upix'r portions of this limestone carries a few small minable deposits of associated magnetite^ hematite, limonite, and carbonate. The next higher rocks, No. Ill of Rogers, are reported to carry ores in a number of places and to have been mined, but such deposits have either not been seen by the writer, or, if seen, have not been confirmed as belonging to this formation. The Upper
MINERAL RESOL'UCES OF VIHQIKU.
IRON. 425
Silurian rocks carry the most abundant ores. Of these the Medina sand- stone, or No. IV, carries little or no commercial- ore. The Clinton, or No. V, is an important ore-bearer. In this there occur at several horizons bedded deposits of fossil ore which are now being mined. It is reported that limonites occur in this formation, but although some of these deposits have been seen by the writer, the horizon has not been confirmed as Clinton. The next higher horizon, the Helderberg, or No. VI, is the greatest ore- t)earing horizon in the State. This horizon carries the largest part of the 50-called Oriskany ore. That part of the formation which carries the ore is the upper part and is limestone. The ore is limonite. The ore is not a t)edded deposit although, in occupying the position which was once occupied by the limestone over considerable areas, it has the appearance of a Dedded deposit. The Oriskany, No. VII, a sandstone, immediately over- lying the Helderberg limestone, locally carries a little ore. The rocks of the Devonian aside from the Oriskany are only rarely ore-bearing. These rocks are almost entirely shales and as such are not favorable for limonite deposits. In a few places Oriskany ore has been deposited in *minable quantities in this shale. In one area it has considerable development and is now mined. All of these occurrences are in the lower few hundred feet of the Devonian. It is not known that ore occurs in other horizons of this great shale formation, which attains a thickness of 4,000 feet in the State. Ifeither the Lower nor Upper Carboniferous is a bearer of any con- siderable deposit of iron ore. Associated with the Greenbrier limestone there is some limonite that may prove minable, but it is not known that any has yet been mined. With the Coal Measures there is some carbonate of iron. This has been mined in West Virginia in charcoal furnace time, but it is not known that any of this has been mined in Virginia.
GeograpUoal Distribntion.
The iron ores are extensively but unevenly distributed over the north- western half of the State. According to topographic divisions they occur in the Alleghany mountains, the Great Valley, the Blue Ridge, and the Dorthwestem part of the Piedmont plateau. The geographical distribution of the iron ores is dependent on the distribution of outcrops of the strata containing them. In general throughout the Valley from the Blue Ridge to the West Virginia line, from the southeast toward the northwest, the surface rock, beginning with the Cambrian of the Blue Ridge, is of successively younger age up to the Carboniferous in the vicinity of the 8tate line. Figure 63 is a generalized cross section of the northwestern part of the State and is intended to show the effect of the position of the
HINBSAI. BSSOimOBe or TIBQINU.
ore in the geological column on the geographical distii- bntion acroes this part of the State. For convenience of discussion the ores are grouped into eight areas. (Fignit 64.) These areas will not include all the ores of the Stite, as there are many scattered deposits. The areas in eidi case are based on a particular kind of ore but may contiin other ores of subordinate importance. These areas maj be named as follows : The Piedmont magnetite area, tlie pyrite area, the great gossan area, the Blue Ridge ana, the fossil ore area, the New River-Cripple Creek area, the Great North Mountain area, and the Oriskany area.
The Piedmont magnetite area is a narrow strip about 150 miles long, lying some 15 to 30 miles southeast of tlie Blue Ridge and parallel to it with its southwest end on the North Carolina line. This b not an area of continnoni ferruginous rocks but, on the contrary, it contains con- siderable intervals which are non-fermginone. The ore- bearing parts of the area are grouped into four districts; the James river district, the Pittsylvania county district, the Franklin-Patrick counties district, and the Gray«n county district. The main ores are magnetites, but there are some specular hematites and minable limonites. The magnetites are of somewhat different nature in ^ different districts, and are associated with different rocks.
The pyrite area is an area of some 100 miles long, lying some 40 miles southeast of the Blue Ridge with the north- east end touching the Potomac. It is not a well-defined area, but a general territory in which bodies of pyrite o«ar from which, in charcoal furnace time, the gossan cap *** locally mined.
The great gossan area is a narrow belt some 60 mil* long, lying in the Floyd-Carroll-Grayson counties plateau region of southwest Virginia, in the northwestern edge oi the area of crystalline rocks. The ore is the gossan e^p of the pyrrhotite lead.
The Blue Ridge area is a narrow strip of the Blue Ridg* 150 miles long, extending from Rosnoke to Front Roye'' It includes several kinds of ores. These are the bedded hematite, the limonite of the Upper Cambrian sandstonB, the liraonites of the western base of these mountains, and small quantities of titaniferous magnetite. The first t^f*
428 MINERAL RESOURCES OF VIROINIA.
of these are important deposits and are now worked. The first is fonnd chiefly in the 25 miles northeast of Eoanoke. The second is found in deposits of commercial importance in a few places along the Blue Bidge. The third occupies quite a definite horizon and occurs at a multitude of places along the line mentioned. The fourth is known in a few plaoes only.
The fossil ore area is a narrow strip some 40 miles long, including the Poor valley, in the counties of Wise and Lee, the extreme southwestern counties of the State. The ore is the bedded fossil ore and occurs in several horizons. It is of commercial importance and is now mined.
The New River-Cripple Creek area is about 30 miles long by 3 miles wide, located in the limestone valley of southwest Virginia, chiefly in the counties of W3rthe and Pulaski. The ore is limonite and is associated with the Cambrian limestone and shale. This area is second in importance in the State.
The Oreat North Mountain area is an area with indefinite boundaries in the northeastern comer of the State along the Virginia- West Virginia line, chiefly in the county of Shenandoah, iyirgi^a. The ore is limonite. It is now worked at one place, but formerly, ft wks one of the important producing areas of the State. ^
The Oriskany area is an area abQiit 40 miles long by 10 miles wide, situated about Clifton Forge as' a' center. . Tbe'*yjres are chiefly the Orift- kany limonite, but there is also fossil ore. ThiS;Arfea is the largest producer of iron ore in the State.
Individual Mines.
In the following description of individual mines it has been attempted to call attention to the iron ore resources of the State and to their distri- bution in four ways. These are by describing producing mines, by describ- ing abandoned mines, by giving the location of old charcoal furnaces, and by giving the distribution of ore-bearing horizons. In the description of producing mines there is little relation between the amount of description and the importance of the mine. An unimportant mine presenting unique features may be described at greater length than an important one which ifi one of a class. Abandoned mines are not necessarily exhausted. Better prices for ore, bettor mining methods and a variety of other reasons may make an abandoned mine profitable to work. A charcoal furnace meant a local mine. In some instances the ore was exhausted, but this is by no means true of all these mines. The Lucy Salina furnace used ore for 40
^ifS^
^/i
*A»
^L ie,
THE
N£W
PUBLIC L
^OtiR
^ BR Any
Ai,|(
IRON. 429
years from the outcrop of a deposit which has since produced 1,500,000 tons of ore. In the space allotted to iron ores in this publication it is not possible to treat in detail the known ore locations^ the mode of occurrence of the ore or the location of reserves. A report which is in course of preparation for the Virginia Geological Survey will treat these in some detail.
Many of the analyses of ores given in the following descriptions have been furnished by the operator of the particular mine to which the analysis refers^ and are thought in most instances to show the mining value of the ores. An analysis of a sample of hand-washed limonite ore usually shows higher values than the same mine will produce in carload lots, where the ore is dressed by machinery. The analyses quoted below usually show silica or insoluble, metallic iron, phosphorus, and metallic manganese. The word silica, or insoluble, is here used as in the source from which the analysis was taken. Silica here probably means insoluble. Washed limonite ore as received at the furnace usually carries 5 to 10 per cent, of uncombined water. Some of these analyses are given for the natural state, that is, as received at the furnace, while others are given as dried at 212^ F. It has not been possible to give all the analyses in the same state. One of these ores dried at 212® P. will carry from 2 to 5 per cent, higher metallic iron than one in the natural state. Comparisons of analyses made in different states should take this difference into account.
COUIITIES WEST 07 THE BLTTE BIPGE.
These counties produce most of the iron ore now mined in the State. They produce all the limestone limonite, the Oriskany limonite, the fossil ore, the limestone magnetite, the Blue Ridge limonite, and most of the Blue Eidge hematite. While nearly all of these counties have minable iron ore, and there are operating mines in various places, the greater part of the ore now mined comes from the vicinity of Clifton Forge and from the southern part of Wythe county.
Frederick County.
Frederick county has Oriskany ore in the western part of the county. This ore was mined more than a century ago for local charcoal furnace use. Zane^s furnace on Cedar creek was active in Jefferson's time. Taylor furnace, 10 miles west of Winchester, was built in 1845. The western part of the county is without railroad facilities and the ores have not been operated in recent years.
430 MINERAL EESOUBGES OF YIBODOA.
Clarke Connty.
Clarke county has the Cambrian measures of the Bine Bidge on its southern border, while the remainder of the county has for its surface rock the Valley limestone. It is not known that ore has been mined from the Blue Ridge measures, but they are reported to carry ore. There is no record of any furnace ever operating in the county, but ore was mined here for the Shannondale furnace in Jefferson county, West Virginia. The ore is the limestone limonite and occurs in a number of places a short distance west of the Shenandoah river.
Berryville mine, — In recent years this ore has been mined at a point iy2 miles north of Castleman's Ferry and 5 miles east of Berryville.
Warren Connty.
Warren county has the Cambrian measures of the Blue Bidge on its southeast border, the Shenandoah limestone in the center of the connty, and the Silurian shales on the west corner, but no Oriskany measureB. Ore has been mined at several places on the west side of the Blue Bidge.
Big Ike mine. — This mine is located a mile or more south of OveraD near the Page county line on the west slope of the Blue Bidge. It is a fault deposit of limonite ore in the Cambrian sandstone. It was recently opened and ore hauled in wagons to Overall for shipment.
Happy Creel' mine, — This mine is located 2 miles south from Front Eoyal at the base of small Blue Bidge hills. The ore is limonite associated with Cambrian sandstone. It is washed in a local washer and transported over a narrow-gauge railway to Happy Creek for shipment. In 1907 this mine was shipping about 3 carloads per day. The analyses of samples of 4 carloads of the ore shipped in 1907 as furnished by the operator, H. J. Seibel, Jr., averaged as follows:
Natural Staie.
Per cent.
Metallic iron 49.48
Phosphorus 0.59
Manganese 0.75
Shenandoah Connty.
Shenandoah county has produced Oriskany ores for a century. In the period just before the Civil War this was a leading iron-producing county of the State. These ores are found distributed over the western p^
IRON. 431
of the county and also occur in the southeastern part in Massanutten Mountain. The western part of the county has supported 6 furnaces and the eastern part 2 furnaces. Paddy furnace was located on the Frederick county line. Two Van Buren furnaces were located a few miles southwest of Paddy. Columbia furnace, built 1810, was located west of Edinburg. Liberty furnace was located west of Columbia, 13 miles northwest of Edin- burg. The Henrietta was located in the western comer of the county. The Caroline and Fort furnaces were in Massanutten Mountain. A part of the ores of the Henrietta furnace are reported to be carbonate. The mines of Caroline furnace are located on the north slope of the South Mountain, 2 miles west of Kennedy's peak. Columbia and Liberty furnaces drew their ores largely from the same banks, of which there were a number in the mountains within 5 miles of the furnaces. Liberty furnace has produced iron through a period of 80 years and is now producing 25 tons of hot blast charcoal iron per day.
Liberty mines. — The chief mines are located on the slopes of Devil's Hole Mountain. The limonite ore occurs in beds with thicknesses up to 15 feet which dip with the bedding of the nearly vertical Devonian shale and lie a few hundred feet stratigraphically above the Oriskany horizon. A narrow-gauge railway connects the mines and furnace with Edinburg. The composition of the ore as furnished by the operators, the Shenandoah Iron and Coal Company, is as follows:
Dried at 2W F.
Per cent.
Metallic iron 41.10
Silica 16.32
Phosphorus 0.35
Manganese 3.40
West mine. — This mine of the Van Buren furnace furnished a sample for the Tenth Census report, which gave:
Dried at 2W F.
Per cent.
Metallic iron 35.78
Phosphorus 0.07
Page County.
The principal surface rock in Page county is the Valley limestone with the Cambrian measures of the Blue Ridge on the southeast border and the Silurian measures of Massanutten Mountain on the northwest border. The ores occur in the Blue Ridge measures, in the Valley limestone, and
432 MINERAL RESOUBOES OF VIBOIKIA.
in the Oriskany. Ores from each of these horizons were mined for char- coal furnaces. While the coimty has never been a large producer of ore, it has produced quite continuously for 150 years.
The Blue Ridge limonite has been worked chiefly in the southern comer of the county. This ore was mined for the Shenandoah Iron Works char- coal furnace and later for shipment and for the G^em, the present coke furnace at Shenandoah.
Beverley, Kimbdll, and Shenandoah Iron Works mines. — For the early furnaces ore was mined along the west base of the Blue Bidge a couple of miles east of the railway line from a number of banks of which the Beverley, Kimball, and Shenandoah Iron Works were the most important. Railways extended to the banks and connected with the furnace at Shen- andoah.
Boyer mine. — In recent years the Boyer mine, located 1% miles south- east from the Gem furnace, was much worked. The composition of this ore, taken from the books of the operators, the Alleghany Ore and Iron Company, is as follows:
Dried at BIB"" F.
Per cent.
Metallic iron 41.35
Silica 21.96
Phosphorus 0.33
Manganese 0.60
Riley ville mine. — This mine is located 2.5 miles south from Rileyville at the west base of the Blue Ridge. It was operated about 1903 and the ore hauled in wagons to Rilejrville. This ore differs from most of the Blue Ridge limonite in that it is associated with sandstone. The composition of the ore, as taken from the books of the Alleghany Ore and Iron Com- pany, is as follows:
Dried at BIB"" F.
Per cent.
Metallic iron 37.08
Silica 25.37
Phosphorus 1.82
The Blue Ridge limonite has been mined in a small way at a number of other places in the county.
Titaniferous magnetite is reported as occurring in the valley of Hawks- bill creek above Marksville. The ore-body is said to be 6 feet wide and to lie in association with a feldspathic rock. This has been prospected.
mON. 433
but it is not known whether it has been mined. The composition of the
ore, as sampled by Frederick Prime, Jr., and analyzed by Booth, Garrett
and Blair, is as follows:
Per cent.
Iron 51.44
Titanic oxide 16.76
PhosphoroB 0.97
The Valley limestone carries ore which has been mined. The Isabella furnace, which was built about 1760, 1 mile north of Luray, used this ore.
Heiston mine. — This mine is located 6 miles northeast from Luray and 5 miles southeast from Kennedy^s peak. The ore is limonite in clay above the limestone. The mine is a pit 300 feet wide by 450 feet long. The oro was mined for the Isabella furnace, but has not been operated for 60 years.
Vaughn mine, — This mine is reported to be located at Vaughn station and to have produced in the 90s 20 tons of limestone limonite ore per day, which was shipped to Pennsylvania.
Catharine furnace, located on Cub run, in Massanutten Mountain, used Oriskany ore. Ore was shown on 3 leads and for several miles on each.
Pit Spring mine. — Since the furnace was blown out this ore was worked in the Pit Spring mine, a mile northwest from the furnace, on the north side of Middle Mountain. The composition of this ore, as taken from the books of the Alleghany Ore and Iron Company, is as follows :
Natural State.
Per cent.
Metallic iron 40.14
Silica 21.58
Phosphorus 0.36
Manganese 1.06
Eookingham County.
Although this county extends across the Valley from the Blue Ridge to the West Virginia line, it has scarcely an Oriskany horizon. The Valley limestone has been faulted over on to the Carboniferous sediments, burying the Silurian and Devonian measures. Massanutten mountains have their southern end in this county and possibly the old Smith furnace drew its ore from the Oriskany measures of these mountains. The southeastern
434 MINERAL E£S0UB0S8 OF YISOIKIA.
border of the oounty carries important ores of the Blue Ridge limonite type. These ores were mined for the Shenandoah furnace No. 2 in the southeastern comer of the county, and for the Mt. Vernon furnace in the southwestern comer.
Fox Mountain mine. — In the southeastern part of the county the chief mine was the Fox Mountain. This was worked for the Shenandoah Iron Works furnace and it was connected with the furnace by a railway. In the 80s this mine was producing 100 tons of ore per day. An analysiB of this ore, as given in the Tenth Census report, is as follows:
Dried at BIB"" F.
Per cent.
Metallic iron 41.71
Insoluble 25.48
Phosphonw 0.22
Aug^ta County.
This county has a geological situation similar to that of Rockingham. However, along the line of the great fault the thrust here waa not so great and the limestone has not buried all of the Silurian measures. In the southwestern part of the county gentle folding has brought Oriskany measures to the surface through the Devonian shale. Along the line of the Chesapeake and Ohio Railway, Oriskany ore has been mined at several places.
Buffalo Gap mine. — At Buffalo Gap ore was mined for the local fur- naces. An analysis of this ore as given in the Tenth Census is:
Dried at 212° F.
Per cent.
Metallic iron 41.95
Phosphorus 0.31
Ferrol mines. — At Ferrol ore was mined for the Ferrol furnace and after this furnace finally blew out the name was a pioneer in producing ore for shipment. An analysis of this ore as given in the Tenth C-ensus is:
Drif^d at 212'' F.
Per cent.
Metallic iron 46.76
Phosphorus 0.20
Southwest of Ferrol ore was mined for the Estelline furnace. In the western comer of the county the Oriskany horizon appears in Walkers Mountain and in Sideling hill.
IBON. 435
The Valley limestone in this county in several places carries limonite ore in its clay. The first furnace west of the Blue Ridge, the Mossy Creek furnace, built in 1760, probably used these ores. This ore was mined at a number of other places for charcoal furnaces and for shipment.
FishervUle mine, — At Fisherville the ore was recently mined for shipment. It occurs here in the clay of the upper measures of the lime- stone near the flint horizon.
Spoitswood mine. — Near Spottswood there is a similar occurrence of ore which was mined for dharcoal furnace.
Lofton mine. — Near Lofton limonite occurs in the limestone clay of the lower limestone measures and was mined for shipment.
Of the Blue Ridge limonite, this county carries a number of deposits. The Mt. Vernon furnace, located in the southeastern part of the county, used this ore for half a century. The Cotopaxi furnace, located in the southern corner of the county, used these ores from a nimiber of banks.
Black Rock mine. — Black Rock mine, located near Cotopaxi Railway siding, formerly operated for charcoal furnaces, has been worked in recent years both by open cut and underground with shaft and tunnels by the Vesuvius Mining Co. This ore sampled by McCreath gave as follows :
Per cent.
Metallic iron 38.96
Insoluble 28.29
Phosphorus 0.10
Bare Bank mine. — This mine is located on the west slope of Bare Mountain and 3 miles southeast of Greenville station. It was formerly much operated for the Cotopaxi furnace and was opened in 1906 with a good showing of ore.
Crozier mine. — This mine, located 900 feet southwest of Bare bank, formerly operated for charcoal furnace, was prospected in 1906 with a good showing of ore.
Blvs Bank mine. — This mine, located 4 miles southwest from the above mines on the end of Cellar Mountain, shows a series of old workings and the ruins of a small washer.
Mine Bank mine. — This mine, located 4 miles up the head waters of South river from Black Rock, was first worked for charcoal furnace and about 1890 was worked for about a year in several cuts. Ore was brought down the mountain by a series of 3 inclines to the washer. A branch railway connected with the Norfolk and Western Railway near Black Rock.
436 MINERAL RE80UB0E8 OF VntOINIA.
The ore is a manganiferous iron ore and is associated with the Cambrian sandstone. This ore sampled by McCreath gave as follows :
Per cent.
Metallic iron 41.13
Insoluble 14.88
PhoephoruB 0.26
Manganese 8.22
Bockbridge Connty.
This county has a geological situation similar to that of Rodringhani and Augusta. However^ the fault which was present on the weetBrn side of the limestone in the latter counties is not present here and ore-beuring Oris- kany measures are brought to the surface in the first folds west of the limestone. These ores were mined for the California, IConnt Hope, Panther Gap, and Bath Iron Works charcoal furnaces. In 1883 the Victoria (Ooshen) furnace was built in this area at Goshen to use these ores. This furnace was claimed to be one of the largest in the United States at the time, producing 100 tons of pig metal per day.
Victoria piines. — ^Twelve miles of narrow-gauge railway brought oie from the Victoria mine on Bratton's run and from mines at Bocid)ridge Alum Springs. The Victoria mines were chiefly on the sonfh slope of Brushy Mountain. They were a series of open cuts which extended for i couple of miles along the base of the mountain. The ore aooording to furnace returns was reported to carry 47 per cent, metallic ircHL
This county has important Blue Bidge limonite ores. These were mined for the Vesuvius furnace near the Augusta county line, for the Bnena Vista furnace at Buena Vista, and for the Glenwood furnace near Balconj Falls.
Buena Vista mines, — These mines were operated by the Jordans for the Buena Vista and Amherst furnaces for 40 years. During this time they were worked by open cut and by shafts and tunnels to a depth of 190 feet Jn recent years these mines have been operated by the Buena Vista Iroii Company. Mining is now largely carried on by steam ghoveL The mines ere now equipped with the most substantial and complete ore dressing es- tnblishment in the State and are producing several carloads of ore per day. Captain Jordan reports that furnace returns for 10 years showed the ore to yield 53 per cent, of metallic iron. The illustration on plate LXIV. figure 1, shows the present steam shovel operation.
Diode mine. — The Coalshire (Coldshort) mine of the Vesuvius furnace
MINERAL BBB0URCB8 OP VIROINIA.
PLATE LXIV.
—Dixie iron mine, n fault deposit, shows operating i Light-colored area to left of operators is ore. The track is on Dark areas on both ^idf:* of the ore are the sandalone wiillfl.
IRON MINES IX THE BLUE RIDGE REGION. VIRGIXIA.
is now operated by the Alleghany « Ore and Iron Company under the 5_ name of the Dixie mine. This mine is located near VesuviuB on the Augusta county line. It is a fault deposit of limonite ore in the Cam- brian sandstone. (Figure 65.) It has been mined for a length of 1,200 feet along the strike of the fault and to a depth of 175 feet and to a width of from 4 to 26 feet. Two miles of tram road connect with the Dixie siding. The illustration on plate LXIV, figure 2, shows a view in this mine. The composition of the ore as furnished by the operators is as follows:
Uetallic iron 4B.iS0
Insoluble I4.4«
Mary Creek mine. — This mine is located 2 miles southwest from Vesuvius on the west slope of the Blue Ridge. The ore is limonite and occurs in shale. This ore was worked for charcoal furnaces and more extensively since at a number of times for shipment.
Buck Hill mine. — This mine is located 3 miles west from the Mary Creek mine. It is limonite ore in clay above limestone. It produced 30,000 tons of ore between 1896 and
yfidvaJe viine. — This mine is lo- cated south of ilidvale on the crest of South Mountain. The ore was said to be limonite and to lie in a small syncline of sandstone, J, E. Lane mined 20,000 tons of ore here , in 1895 and 1896. ;
438 MINERAL RESOUBOSS OF VIRGINIA.
Highland Connty.
This county lies west of the Valley tier of counties. Its surface is largdy Devonian shale with anticlinal folds of the Silurian measures exposed. The county has only small streams and is without a railway. Whether there was ever any operation of iron ore in the county is not known. The county contains abundant outcrops of the Helderberg limestone, but it is not known whether this carries ore in commercial quantity. The Clinton horizon outcrops abundantly on the mountain slopes above the Helderberg limestone. Fossil ore is reported in the slopes west of Sounding Knob.
Bath Connty.
This county has a geological situation similar to that of Highland. It h traversed by 2 railways in the southern part but otherwise it is without ttansportation facilities and iron ore has not been developed. Like High- land county it has abimdant outcrops of both the Helderberg and Clinton horizons. It is not known whether limonite ore occurs in commercial quantity, but ore is found on McClung's Ridge and on Jack Mountain. Fossil ore with a thickness of 2 feet is reported in the valley east of Warm Spring Mountain.
Alleghany Connty.
This county has a geological situation similar to that of Highland and Bath counties. It is crossed by the Chesapeake and Ohio Railway and by streams which, in the days before the railway, furnished an outlet for large quantities of charcoal pig iron. The county is largely covered with Devo- nian shale through which anticlinal moimtains and ridges have brought the Oriskany measures to the surface. This county has the greatest number of large mines and is the largest producer of iron ore of any county in the State. The following figures of shipments from this coimty are taken from the reports of the American Iron and Steel Association.
Iron ore Year (long tons)
1887 160,000
1888 166,126
1893 175,140
1894 142,808
1895 209,619
1901 212,690
1902 199,690
1903 196,126
In charcoal furnace days this county supplied the Dolly Ann, LucT Salina, Australia, Clifton, and Rumsey furnaces. All of these furnaces
IRON. 439
except the Clifton were operated by the Jordans. To-day the county has 6 modem coke furnaces which are run largely on ores mined in the coimty. The Clifton furnace stands in the gap at Iron Gate. It used ores from the southeast side of Rich Patch Mountain near the furnace. These same l«anks have been operated somewhat since then. The Rumsey Iron Works furnace stood on Dunlaps creek near the present Mud tunnel on the Chesa- peake and Ohio Railway.
Rumsey mine. — This mine is located 3 miles southwest from the fur- nace site at the head of Harmon branch on the southeast slope of Sweet Spring Mountain. It has been operated for a mile along the mountain in various places. A broad-gauge railway connected with the furnace at Covington.
The Dolly Ann furnace was located 3 miles east of Covington between Peters Ridge and Fore Mountain, using ores mined near at hand.
Dolly Ann mine, — This mine has been extensively worked for the last 20 years on the slopes of these two mountains and in the valley between them for a mile or more along the mountains. A broad-gauge railway connects with the furnace at Covington. This is one of the large mines of the dis- trict. It produced in 1897, 71,124 long tons of iron ore. The composi- tion of the ore as furnished by the operators, the Low Moor Iron Company,
is as follows : Per cent.
Metallic iron 44.32
Insoluble 24.16
Iron Mountain mine. — This mine lies in the same valley and extends northeastward for several miles. The ore has been mined chiefly on Fore Mountain on the outcrop of the deposit.
Lucy Salina and Australia furnaces were located on Simpsons creek be- tween Brushy Mountain and North Mountain. They drew their ores from the southeast slope of Brushy Mountain. These mines, now known as the Longdale, have the greatest total production of any mines in the State. The Jordans worked them for 40 years for the charcoal furnaces, and since 1869 they have given the Longdale Iron Company 1,500,000 long tons of ore, producing, in 1889, 80,452 tons. The mines have been worked for a mile along the mountain and on the slope, chiefly underground, for 500 feet. Eleven miles of narrow-gauge railway connect the mines and furnaces with the Chesapeake and Ohio Railway at Longdale station. The composi- tion of the ores as furnished by the operators is as follows :
Per cent.
Metallic iron 48.20
Insoluble 13.83
Phosphorus 0.42
440 MINERAL RE80UB0E8 OF VIRGINIA.
Fancy Hill mine, — This mine ifl located north of the Longdale furnaces on the south slope of Mill Mountain. It has been operated in recent years. A narrow-gauge railway connects with the furnaces.
A number of large mines have been developed since charcoal furnace days. These are the Stdck, Low Moor, Rich Patch, and Fenwick.
Siack mine, — This mine is located on the northwest slope of Sweet Spring Mountain 5 miles southwest of Mud tunnel on the Chesapeake and Ohio Railway. This mine was one of the first to be opened for shipment and has been producing for 25 years. It is mined for a half mile along the mountain by open cut, and by underground work for several himdred feet on the slope. A narrow-gauge railway connects with the Chesapeake and Ohio Railway at Backbone. The composition of the ore as furnished by the operators, the Low Moor Iron Company, is as follows :
Per cent.
Metallic iron 46.67
Insoluble 19.72
Low Moor mine, — This mine is located 2 miles south of Low Moor between Rich Patch and Horse mountains. It was opened about 1878 and has produced steadily until the last few years with a total production of about 1,000,000 tons. Ore was mined on several folds of the formation, located on the lower slopes of the 2 mountains and in the valley between them. A broad-gauge railway connects with the furnace at Low Moor. The composition of the ore as furnished by the operators, the Low Moor Iron
(..^ompany, is as follows :
Per cent.
Metallic iron 46.62
Insoluble 17.60
Rich Patch mine, — This mine is located southwest from the Low Moor mine in the same valley. This is one of the more recent mines, being first opened about 1895. It is one of the largest producers in the State, yield- ing 90,000 tons in 1902. Ore is mined chiefly on one syncline on both sides of the valley. Mining is mostly underground but there is some steam shovel work done. A broad-gauge railway connects with the ChesapeaJce and Ohio Railway at Low Moor. The composition of a sample of the ore taken from 29 carloads at the Goshen furnace stock pile as furnished by the operators, the Goshen Iron Company, is as follows:
Per cent.
Metallic iron 42.90
Silica 25.60
Phosphorus 0.33
Manganese 0.78
inoN. 441
Potts Valley mine. — This was a small mine, located west of Covington and operated for a few years recently. The composition of the ore as furnished by the operators, the Alleghany Ore and Iron Company, is as
follows: Per cent.
Metallic iron 41.10
Insoluble 24.41
Manganese 0.69
Phosphorus 0.43
Potts valley lies southwest from Covington between Potts Mountain on the south and Peters and Warm Spring mountains on the north. This valley was known to contain ore many years ago but it had no railway till 1906, when a line was built by the Chesapeake and Ohio Railway. Exten- sive developments have recently been made by the Low Moor Iron Company at various places in the valley. The valley carries a number of folds of the Oriskany measures and some of these are ore-bearing. The chief develop- ments are at Bess and Double Ridge mines.
Bess mine, — This mine is on Chisle3r'8 Run, 2 miles south from its mouth. This is on one of the valley folds and has a good showing for a large mine.
Double Ridge mine, — ^This mine is located a couple of miles southwest from the Bess mine on the north slope of Potts Mountain.
CHven mine, — Other prospects are the Given bank at the southwest end of Mill Ridge, the Robinson and Bennett on the south slope of Warm Spring Mountain.
Fossil hematite ore has been mined in two places in the county, namely, at Iron Gate and on Horse Mountain.
Iron Oate fossil ore mine, — ^This mine is located on the northeast side cf the Jackson river at Iron Gate. It was operated several years in the early 80s. Ore has been mined in the face of the gap on the slopes and crest of the fold and on the strike of the formation away from the river for some 900 feet. The bed is said to be somewhat under 2 feet in thick- ness. A view of this mine is shown in plate LXVII, figure 1. The com- position of the ore taken from Bulletin No. 285 of the IT. S. Geological Survey as furnished by the Longdale Iron Company is as follows :
Per cent.
Metallic iron 46.50
Insoluble 19.90
Phosphorus 0.49
Horse Mountain mine. — ^This mine is located on the southeast slope of Horse Mountain, well up on the mountain, and just north of the Low Moor
442 MINEBAL RESOURCES OF YIRGINIA.
Oriskany mine. This was opened in 1905 and is now producing 1^200 or more tons per month. The bed has a thickness of about 2 feet. The composition of the ore, as furnished by the operators, the Low Moor Iron
Company, is as follows : Per cent.
MeUllic iron 44.82
Silica , 15.51
Botetourt County.
This county has abun(iant Outcrops of the Oriskany horizon, chiefly in its northwestern half. These have furnished ore for charcoal furnaces for a century and have since produced the greatest mine in the State. The Etna and Eetreat furnaces were located on the east side of Purgatory Moiint- ain and used ores from this mountain. Since these furnaces went out of blast the ores have been mined in small amount for shipment. The Salis- bury furnace, located on Catawba creek near its junction with the James river, used Purgatory Mountain ores. Catawba furnace was located on Catawba creek, 11 miles west of Fincastle. Jane and Eebecca furnaces were located near Dagger's Springs and used ores from Sand Bank Mountain.
Sand Bank mines. — ^These mines were recently worked by the Princess Iron Company. An incline and broad-gauge railway connected the mines with the Chesapeake and Ohio Bailway at Gala.
The southeast slope of Rich Patch Mountain has been mined at intervals along the border of the county. The ore occupies the position of the upper member of the Helderberg limestone and has local thicknesses of 40 feet. The ore has been mined several hundred feet on the dip and it is known to extend in places 700 feet.
CaJKe mine. — The Callie furnace and mines are located on the south slope of this mountain near the Alleghany county line. Formerly a narrow- gauge railway connected with Clifton Forge. This mine was re-opened by the Princess Furnace Company in 1907. An analysis of the ore, as given in the Tenth Census report, is as follows: .
Dried at 212° F,
Per cent.
Metallic iron 46.17
Phosphorus 0.07
WUton mine, — This mine joins the Callie on the southwest. It is now operated by the Princess Furnace Company and supplies ore to the Prin* cees furnace. A narrow-gauge railway connects the mines with the furnace at Olen Wilton.
.'
MINKIIAl. HKHiHItri:s in- VIKIilM.'.
ntON ORE OITCIIOI'S AXD WASIIKR, Ul.rK KIIMJK RKGIOS. VERGlXU-
IBON. 443
Circle mine. — This mine joins the Wilton on the sonthwest. This was opened in 1906 by the Longdale Iron Company.
Roaring Run mine. — The Roaring Rnn furnace and mines were located 7 miles southwest of Soaring Run, northeast of the Oriskany mine.
Orace mine. — The Grace charcoal furnace and mines are located 7 miles southwest of Roaring Run, northeast of the Oriskany mine.
Oriskany mine. — This mine is located 4 miles west from Oriskany station and 11 miles directly south from Covington, partly in Botetourt county and partly in Craig. This is the greatest iron mine in the State. It has produced 1,000,000 tons of ore and is now producing at the rate of 400 tons per day. A narrow-gauge railway connects with the Chesapeake and Ohio Railway at Oriskany. This mine furnishes most of the ore for the company's 3 furnaces which are located at Iron Gate, at Buena Vista, and si Shenandoah. An illustration of this mine is shown in plate LXVII, figure 2. The composition of the ore as furnished by the operators, the Alleghany Ore and Iron Company, is as follows :
Per cent.
Metallic iron 45.88
Insoluble 16.29
Phosphorus 0.12
Manganese 2.18
In the foothills of the Ritch Patch Mountain below the Oriskany mine some mining has been done.
Ried mine. — An operation is now carried on here by the Alleghany Ore and Iron Company under the name of the Ried mine. The com- position of the ore, as furnished by the operators, is as follows :
Per cent.
MetaHic iron 40.37
Insoluble 21.81
Phosphorus 0.43
Manganese 0.69
Big HUl mine. — This mine is located 3 miles south of Glen Wilton and operated by the Longdale Iron Company. Big Hill is a small anti- clinal which brings Oriskany measures to the surface through the Devonian shale;
Of. the Blue Ridge ores, this county has important deposits both of limonite and of red hematite. The two Cloverdale furnaces and the Arcadia furnace probably used this limonite. Ore has since been mined along both the xiorihw.est and the southeast base of the Blue Ridge.
Oruhb or Lynchburg mine. — This mine is located 2 miles northwest of Blue Bidge Springs and 11 miles northeast of Roanoke on the southeast
444 MINERAL BESOUBOES OF VIBOINIA.
slope of the Blue Eidge. The ore body, located in shala near the contact with the Valley limestone, is about 40 feet thick and dips with the bedding toward the mountain. This is one of the largest of the Blue Eidge limonite mines and has been operated for 25 years. It is mined by open cut and undergroimd to a vertical depth of 180 feet. A branch of the Norfolk and Western Railway extends from Blue Eidge Springs to the mines. Plate LXV, figure. 2, is an illtistration of the Grubb washer and mines. The compositiori.of ' the ore, as furnished by the operators, the A^irginia Iron, Coal and Coke Company, is as follows:
Natural State,
m
- Per cent.
MetallkJ iron 41.20
Silica 14.08
Phosphorus 1.23
Manganese 1.13
Crozier mine. — This mine is located a mile east of the Grubb mine and similarly situated except that it is at the foot of the mountain in relatively flat country instead of being on the slope of the mountain.
Houston mine, — This mine is located 2 miles northwest from the Grubb, on the opposite side of the Blue Eidge. In the 80s the mine was operated in a series of openings and produced considerable ore. A railway connected with the Norfolk and Western Eailway at Honston. A number of other similar mines have been operated in this vicinity on both sides of the Blue Ridge.
Blue Eidge heniatito, known as specular ore, occurs in the southeastern part of the county near the crest of the Blue Eidge. In the vicinity of the Grubb mine this type of ore has been mined at intervals for a distance of 4 miles along the southeast slope of the mountain. Of this distance about 2 miles are in Bedford county. The ore is from 3 to 6 feet thick in iTiucb folded beds which have in general a steep dip. The largest operation is the Edith mine.
Edith mine. — This mine is located % mile northeastward from the Grubb mine, well up on the side of the Blue Eidge, 500 feet above the bottom of the Grubb mine. An incline and a narrow-gauge railway connects with the Grubb mine. The composition of the ore, as furnished by the operators, the Virginia Iron, Goal and Coke Company, is as follows:
Natural State,
Per cent.
Metallic iron 37.09
Silica 38.91
Phosphoma 0.37
Manganese 0.27
■• »• :,
■■■ V/- ■ -* ■
I
Tv
' ^
■ /
MINKIIAI. BKSOriK'KS lif VlltiilNI
I'T.ATE 1.XVI.
Fig. i. — Arcadia iron mine. IRON (HEMATITE) MINES, BLUE RIDGE REGION, VIRGINIA.
IRON. 445
Orubb Specular mine. — This mine is located immediately southwest of the Edith mine and is similarly situated. Operated by the Virginia Iron, Coal and Coke Company.
Lemon mine. — This mine is located a mile southwest of the Edith. r>perated by R. P. St. Clair. Ore is hauled in wagons to the Grubb tipple.
Near Buchanan the hematite ore has been mined for several miles along the northwest side of the Blue Ridge. The bed here is from 4 to 6 feet thick and dips at high angles northwest. It has been faulted or folded 80 as to present several outcrops.
Arcadia mine. — The chief mine is the Arcadia, operated by the Pulaski Iron Company. This mine is located 4 miles south of Buchanan, well up on the Blue Ridge, 1,000 feet above the Valley. Ore is taken down the side of the mountain on aerial tramway and over a mile of narrow- gauge railway to a branch of the Norfolk and Western Railway. An illustration of one of the openings is given on plate LXVI, figure 2. A sample of the ore taken and analyzed by the writer gave as follows :
Per cent.
Silica 41.14
Metallic iron 33.34
Wood mine. — ^This mine is located immediately west of the Arcadia. It is now operated by 6. G. Harvey, and ore is delivered in wagous to the Arcadia narrow-gauge railway. An illustration of this mine, showing the workings on two outcrops of the ore, is given on plate LXVI, figure 1. These workings are reported to intersect at the upper end. An analysis of this ore, as given in the Tenth Census report, is as follows:
Dried at £12'' F.
Per cent.
Metallic iron 42.89
Phosphorus 0.41
Craig County.
This, county has several parallel ranges of great mountains of which fipiHiig Creek Mountain, Bald Mountain, Potts Moimtain, and presumably Jbfais Mountain carry Oriskany measures. In early days there was a dbmoil fuiiace and a forge on Craig's creek, 1.5 miles above New Castle, which used these ores. Except in the eastern end of the county there is no railway, and elsewhere it is not known what the horizon carries in the way of ore.
446 MINERAL RESOURCES OF VIROINIA.
Oriskany mine. — ^The larger portion of the big cut of the main Oris- kany mine lies in Craig county. The mine is described under Botetourt county.
Fenwicl' mine. — This mine is located on the southeast slope of Bald Mountain^ which is a spur of Bich Patch Mountain^ near the Botetourt county line, and joins the Oriskany mine on the northeast. Opened in 1900, this mine produces 4,000 to 7,500 tons of ore per month, produdug 55,973 tons in 1904. It has been operated for several miles along fte mountain by steam shovel and underground work. An anilysiB of the ore, as furnished by the operators, the Low Moor Iron Company, is as
follows: Percent.
Metallic iron 44.60
Silica 22.30
Boanoke County.
The northern part of this county is covered with mountains of Carbo- niferous sediments. Of the Blue Ridge limonite the county has one large mine, the Rorer, and a number of smaller ones.
Rorer mine. — This mine is located 3 miles south of Boanoke, on the west side of a small mountain. It was opened for shipment about 1880 and has had a constant production ever since. The mining i& now largely done by steam shovel. The composition of the ores, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent.
Metallic iron 38.68
Silica 20.91
Phosphorus 1.14
Manganese 1.20
Southwest of Horor, on the strike of the formation, ore has been minc^ for a mile or more. Although there is no topographic feature along this line, all of the ores are apjiarently similarly situated stratigraphicallj.
Griffin mine, — Of these mines the Griffin, a small mine, was operated in 1903 by the West End Furnace Company.
Gale mine. — This mine is located a mile southwest of Borer. This is one of the largest of these mines. It is not now operated.
Castle Rock mine. — This mine is located 6 miles southwest of Boanoke and 2 miles northwest of Cave Spring in a rather flat area near Sag«r Loaf hill. This was operated about 1895. A railway formerly Connected with the Koanoke Southern Railway.
UIXKRAL BBSOURCK
l(. 1. — Iruii (iule tt<>li "! llie JuckiKin river Iliniii);h Itii-h Patch Mountain. KoHRil iron art vran niiued from llm fnr Hi<Ie nf th<- jjup ubuve the lower siandstone. The while ridges nre ('lintuD and Medina snodstoQe. Oria- knny nre wiih mined on the far Hlopp of the muuntiiin.
Ill
K
*
IRON. 447
Siarkey mine. — This mine is located 4 miles southwest of Eoanoke and % of a mile from Starkey. It was operated in a small way by the Pulaski Iron Company about 1902. Tlie ore was hauled in wagons to Starkey.
Griffin specular mine, — This mine is located 6 miles southwest of Eoanoke on the north slope of Bucjc Mountain. Ore has been mined but not shipped. This is the Blue Ridge bedded red hematite and has a thickness of 2 feet. This location is of interest, as it is the most south- westerly known working of this type of ore. A sample taken from the ore, which was piled at the mouth of the mine and analyzed by the writer, gave as follows:
Per cent.
Metallic iron 40.97
Silica 31.16
Montgomery Connty.
This county carries ore at its north border in the Oriskany horizon near the crest of Gap Moimtain which was mined for the Sinking Creek furnace. It also carries a little ore near the contact with the Valley lime- stone and the underlying shales near the south border of the county. This is reported to have been mined south of Christiansburg.
Oiles Connty.
This county has had iron ore mined at 3 different points, namely, neai Newport in the southeast comer of the coimty, near Ripplemead on the New river, and near Interior on Stony creek. Near Newport the Sinking creek furnace built in 1873 operated on local ores. Ores were mined above the limestone on the south side of Spruce Run Mountain and at other places about Newport.
Johnson mine. — This mine is located ^. mile above Big Stony Junc- tion and on the east side of the New river. The ore is magnetite and occurs in the Valley limestone. It appears to have been mined chiefly below the surface of the New river. It was mined in a small wav some- time in the SOs and ore shipped to Pennsylvania. The ore is of Bessemer £rade. The composition, as given by McCreath, is as follows:
Per cent.
Metallic Iron 63.55
SUica 6.21
Phosphorus 0.05
Sulputtr 0.002
448 MINERAL RESOURCES OF VIROINIA.
Porterfield mine. — This mine is located 3 miles southwest from the Johnson mine on the strike of the strata. Ores have been mined in several places in a small way from the clay above the Valley limestone. It was worked for a few months in 1906 and ore hauled in wagons to Ripple- mead. The composition of the ore, as reported by McCreath, under the
name of Pack Tunnel mine, is as follows :
Per cent.
Metallic iron 48.82
Siliceous matter 19.76
Phosphorus 0.06
Sulphur 0.16
Interior mines. — The south side of Peters and East River mountains carry Oriskany measures with some ore. This valley is the southwestward continuation of the Potts creek valley. It has recently been prospected for iron ore and surveyed for a railway. Ore has been mined at the Interior mine, located ^ mile northwest of Interior on the south slope of Peters Mountain. The ore was taken down the mountain on an incline to a washer located on the Big Stony Railway. Some ore was hauled to Interior in wagons from the north slope of the opposite Pork Mountain.
Pnlaski County.
This is a Valley county. The Oriskany horizon occurs on the north- west border of the county near the crest of Walker Mountain and in the western part in Draper Mountain. This latter occurrence carries a number of producing mines. The southern part of the county has limestone limonite ores of a part of the New Eiver-Cripple Creek area. This county did not produce much for charcoal furnaces and its production was in comparatively recent times. It lias two charcoal furnaces in the southern part, and has had a bloomery forge. The Radford furnace, located 8 miles southeast of Pulaski City, was built in 1868, while Boom furnace, in the southern comer of the county, operated from 1882 to 1906. This is the last one of the Virginia cold blast, water-power charcoal furnaces. Pulaski City, standing at the gateway of the New River-Cripple Creek area, has two active modern coke furnaces and is the main center of iron smelting in the district. Some of the best mines of the district are m this county and are now operated.
Clark's bank. — ^This mine is located a mile north of Allisonia. The ore is limonite. This mine has been operated several times for iron ore and, in 1902 and 1903, for zinc, producing 8,000 tons of that ore from the BtODB opening that was mined for iron. A narrow-gauge railway connected
IRON. 449
with the Norfolk and Western Railway at Dalton, 1 mile north. The mine is not now operated and the track has been removed. The composition of the ore, as furnished by the New River Mineral Company, is as follows:
Dried at 212° F.
Per cent.
Metallic iron 52.60
Silica 5.59
Phosphorus 0.15
Manganese 0.40
Radford Furnace mine, — This mine is located on Mack^s creek, 2 miles southwest of the New river railway bridge. The ore is "mountain" ore. The mine was operated years ago in a small way for Radford furnace.
Tasker mine. — This mine is located about 1 mile east of New river railway bridge and 2 miles northeast of Allisonia. This mine produced 9,000 tons of "mountain'' ore in 1898-90, and in 1907 is operated by the West End Furnace Company, producing 100 tons per day. The com- position of the ore, as furnished by the operators, is as follows:
Per cent.
Metallic iron 47.80
Silica 13.40
Phosphorus 0.14
. Manganese 0.44
Farris mine. — This mine is located about 3 miles southeast of Boom furnace on the northwest slope of Mack's Mountain, on the contact of limestone and sandstone. The ore is mostly "mountain" ore in thin seams in the clay. This was one of the best producing mines in the district. It was opened in 1904 and is said to have produced 30,000 tons of ore in that year. A narrow-gauge railway connects with the Norfolk and Western Railway at Allisonia. The composition of the ores, as furnished by the operators, the Pulaski Iron Company, is as follows:
Dried at 2W F.
Per cent.
Metallic iron 39.59
Manganese 0.48
Phosphorus 0.39
Rich nUl mine. — This mine occupies the point of the ridge which lies between New river and little Reed Island creek. The ore is limonite. It has produced more ore than any other mine in the district. Opened for modem mining about 1886, it has produced 600,000 tons of iron ore since that time. The washers are located at the foot of the ridge on the
450 MINERAL RESOURCES OF VIROINIA.
north side and deliver to railway cars. A view of this mine is shown (m plate LXIX, figure 2. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company^ is as follows:
Natural State.
Per cent.
MeUllic iron 43.81
Silica 14.66
Phosphorus 0.18
Manganese 0.66
Reed Island mines. — These are a series of mines located <m ibe nine ridge with the Rich Hill mine, which together with this mine extend for 114 miles, occupying the larger portion of the limestone lidgBy which rises 200 feet above New river and Little Reed Island creek. The ore is limonite and occurs distributed through a considerable thicknefls of cIa7< These mines have supplied Boom furnace and have also fmniahed con- siderable quantities of ore for shipment. The washers are located on the south side of the ridge on Little Reed Island creek and deliver to railway cars. A view of this mine is shown on plate LXVIII, figure 2. The com- j>osition of the ores, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent.
Metallic iron 42.42
Silica 18.92
Phosphorus 0.17
Manganese 0.37
Under Rock mine. — This mine is located a mile southwest of Boon furnace on the west bluff of Little Reed Island creek. The ore is limonite. Tlie iTiine has not been operated for several years.
Draper Mountain lies in Pulaski and Wythe counties, just beyond the northoast corner of the New River-Cripple Creek area. The mountain is an anticline wliich has been faulted on the northern and southern sides and wliose crest, and most of the northern limb, have been removed bj erosion. Tho strata involved in the folding are great thicknesses of Onlovician. Silurian, Devonian, and Carboniferous sediments. The Ordovician shales ajipear in the eroded crest of the anticline, the Draper valli'v. Tho Silurian rocks, chioflv sandstones, form the elongated crosoeniic crest of the mountain. The Oriskany horizon appears in normal pasition on the north side and on the ends of the mountain. • South of Pulaski it is l)ioii^^lit to tho surface through the Devonian shales by a
UINBBAl. BHSOUBCES OF VIRGINIA.
PLATB LXVIIL
FiK. 2— ReM Inland
IBON. 451
fault. The Devonian and Carboniferous shales appear chiefly on the north slope of the mountain. Oriskany ores appear in the vicinity of the Oriskany horizon and other limonite ores occur at the contact of the shales and limestones. In Pulaski county this mountain carries a number of mines, chiefly Oriskany.
Clayton mine. — This mine is located 1 mile south of Pulaski on the north slope of Draper Mountain. The ore occupies the position of the Helderberg limestone which a fault has here brought to the surface. The mine was opened for shipment in 1905. A narrow-gauge railway delivers crude ore to the washer at the foot of the mountain and washed ore to E^laski. The composition of the ore, as furnished by the operators, the Ehilaski Iron Company, is as follows:
Dried at 212'' F.
Per cent.
MetaUic iron 41.12
Manganese 0.51
Peak Knob mines, — The Peak Knob mines are a series of openings about Peak Knob, the east end of Draper Mountain. The horizon of the Clayton mine is traceable eastward 2 miles and about the base of Peak Ejiob and around to the south side of the mountain. Lump ore has been mined on three sides of the Knob. Ore is now mined on the north side by Hagar and Mahady and hauled in wagons to Pulaski, and mined on the east end of the mountain by Hatcher and Shaffer and hauled % mile to a railway siding. The composition of the ore as mined in 1898, as furnished by the New Eiver Mineral Company, is as follows:
Dried at 212'' F,
Per cent.
Metallic iron 53.46
Silica 4.58
Phosphorus 1.22
Manganese 0.40
Wythe County.
Wythe county is a Valley county. It has the greatest development of limestone limonite ores of any county in the State and includes within its boundaries the greater portion of the New River-Cripple Creek area. K has the Oriskany horizon on the northwest border near the crest of Walker Mountain and in small amount in Cove Mountain and has this norizon-producing ore in Draper Mountain in the northeastern part of the
462 MINERAL RESOURCES OF VIRGINIA.
county. This county has produced iron from the soft limestone Hmonite ores for over a century and has had a total of more than a dozen charcoal furnaces. The pioneer furnaces of the county, built at the beginning of the last century, were the Cedar Run, Speedwell, and Poplar Camp. Of these the Cedar Run (Parry Mount) furnace with three successive stacks was operated by the Grahams from 1800 till the coming of coke furnaces. A number of charcoal furnaces were built in this county in the early SOs. Two coke furnaces are now operated, one at Max Meadows and the other at Ivanhoe.
Barren Springs mine. — This mine is located 3 miles west of Boom furnace on the south bank of New river. It occupies the upper portion of a knoll, which rises some 200 feet above New river, and consists of a series of operations over a large acreage in a rather shallow liraestone clay. A narrow-gauge railway connects the operations with the washer which is located beside the Norfolk and Western Railwav. This ore was mined for the Barren Springs furnace in 1854. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Com- pany, is as follows:
Natural State.
Per cent.
Metallic iron 44.27
Silica 12.60
Phosphorus 0.14
Manganese 0.47
Bertha mine. — This mine is located 1 mile south of the Barren Springs mine. However, the workings of the two mines connect and together they occupy an area 2 miles long. Prior to 1898 this was operated by the Bertha Mineral Company for zinc and the mine was the greatest producer of soft zinc ores in the State. Since that time it has been worked in the same pits by the Pulaski Iron Company for iron ore. The ore is limonite. It is washed at Bertha station, 1 mile west. The composition, as furnished by the operators, is as follows:
Natural State.
Per cent.
Metallic iron 44.98
Manganese 0.53
From Carter's station, which is located 2 miles up New river fro^i Barren Springs, there extends southwestward a strip of ore territor}' which 18 6 miles long by ^^ mile wide. This was first worked for the Cedar Run furnace in 1800 and quite continuously ever since, and in the last decade.
moN. 453
extensivelv. It has been worked on most of the hills in the area. The Carter bank at the northeast end is not now worked nor is the Walton mine at the southwest end. A narrow-gauge railway extends lengthwise through the area and to Foster Falls and at the northeast end delivers to a wire tramwav which crosses New river. The Red Ilill or Cedar Run and the Sanders mines are now operated by the Virginia Iron, Coal and Coke Company. The ore is all limonite in clay above limestone.
Carter bank. — This mine is the most easterly of these operations. It consists of a long, narrow, deep cut in clay between limestone. It is not now operated. An analysis of this ore, as given in the Tenth Census report, is as follows:
Dried at 212'' F.
Per cent.
Metallic iron 55.90
Phosphorus 0.12
Cedar Run mine, — This mine consists of a series of operations scat- tered over several miles of territory west of the Carter bank. It is now operated chiefly by steam shovel.
Sanders mine, — This mine is located west of the Cedar Run hiine and consists mainly of one large operation which is carried on by the steam shovel iand the hydraulic methods.
Walton mine. — This mine is located a mile or two west of the Sanders mine and consists of a number of pits. It was formerly mined for the Walton furnace, which was located near the mine. The composition of the ores of these mines, as furnished by the operators, is as follows:
Natural State.
Sanders Cedar Run Walton
Per cent. Per cent. Per cent.
Metallic iron 46.03 41.17 41.90
Silica 10.90 19.31 13.80
Phosphorus 0.15 0.22 0.13
Manganese 1.09 0.97 1.03
Morris mine. — This mine is located just south of the Bertha mine on the north slope of Roaring Falls Mountain. It produces "mountain" ore, which is the most massive of anv in the district. It is a small mine and but recently opened. Lump ore only is mined and hauled in wagons to Barren Springs. The composition of this ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
454 MINERAL RESOUROBS OF VIROINIA.
Natural State.
Per cent.
Metallic iron 40.38
Silica 20.11
Phoephonis 0.56
Manganese 0.47
Hurst mine. — This mine is located about a inile south of Little Beed Island creek near the Pulaski county line on the contact of the limestone and the sandstone. The ore is semi-limonite. Mining is by the sloioe trough method with water pumped from the creek. The ore is sluiced down the hill to the washer near the railway. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent.
Metallic iron 40.67
Silica 18.09
Phosphorus 0.63
Manganese 1.24
Patterson mine. — This mine is located immediately south of the Huwt mine, but has been operated below the contact of sandstone and limestone in various openings for % of a mile southward. The washers deliver to the railway. The ore is limonite. The mine was abandoned in 1906. The composition of the ore, as furnished by the operators, the Pulaski Iron Company, is as follows:
Dried at 212'' F.
Per cent.
Metallic iron 49.86
Manganese 0.30
Crawford mine. — This mine is located 2 miles southwest of the Pat- terson mine and 3 miks east of Foster Falls station, near the contact of the limestone and sandstone, but over the limestone. The ore is semi- limonite. The mine has been operating steadily for years. The washers are on the railway. The composition' of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Per cent.
Metallic iron 35.61
Silica 28.50
Phosphorus 0.069
Manganese 0.30
Tipton mine. — This mine is located about 3 miles southeast of Foster Falls station. It is a contact mine but chiefly above the shale and sand- stone and produces "mountain^* ore. This was one of the first t^^
r->..
< I
'LATE LXIX.
IBON. 455
opened for modern mining and is second in point of production in the district, having produced nearly 600,000 tons of ore. The washer near the mine delivers to the railway. The composition of the ore, as furnished by the operators, the Pulaski Iron Company, is as follows :
Dried at 212'' F,
Per cent.
Metallic iron 43.60
Phosphorus 0.74
Manganese 1.66
Foster Falls mines, — On the south slope of Roaring Falls Moimtain near the contact of the limestone and the sandstone, for a distance of 3 miles east of Foster Falls there is a series of mines which are grouped under the above head. Some of the mines are above the limestone while others are above the shale. The ores are therefore limonite and "mountain'' ore. The **moimtain'' ores are characterized by high manganese content. The mines were first worked for Poplar Camp furnace a century ago and extensively in recent times. A narrow-gauge railway extends from Craw- ford mine through Foster Falls mine to Foster Falls. The composition of these ores, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State,
Per cent.
Metallic iron 35.96
Silica 17.10
Phosphorus 0.26
Manganese 4.62
On the west side of the river at Foster Falls, contact mines have been worked for a mile or more by the Virginia Iron, Coal and Coke Company. The ore is semi-limonite. The mines are connected with Foster Palls by narrow-gauge railway and include the Hematite and Posey,
HemaiUe mine. — ^This mine lies just west of Foster Falls. It is an old mme now operated in a small way by hydraulicing. A view of this mine is shown on plate LXIX, figure 1. The composition of the ore, as furnished by the operators, is as follows :
Natural State.
Per cent.
Metallic iron 42.90
Silica 19.17
Phosphorus 0.09
Manganese 0.67
456 MINERAL RESOURCES OF VIRGINIA.
Posey mine, — This mine lies west of Hematite. It was operated about 5 years by hydraulicing and sluicing, and abandoned in 1905. A new operation was opened west of Posey. The composition of the Posey ore, as furnished by the operators, is as follows:
Natural State.
Per cent.
Metallic iron 45.04
Silica 19.36
Phosphorus 0.11
Manganese 0.36
Poplar Camp mine. — This mine is located 1.5 miles southeast of Jack- son's Ferry. This is a fault deposit lying between the limestone and the sandstone. The mine had been operated for lump ore only up to 1906, when it was opened by the Pulaski Iron Company on a larger scale and ore hauled in wagons to the railway at Jackson^s Ferry. A sample taken and analyzed by the writer gave : per cent.
Metallic iron 40.77
Insoluble 13.92
Phosphorus 1.19
Manganese 6.80
Southwest ward from Poplar Camp mine along the north foot of Poplar Camp Mountain in a distance of 3.5 miles there is a series of small mines nearly identical in situation with the Popular Camp mine. This line seems to be a fault line where the sandstone has been thrust on top of the lime- stone and the ores are lying in the mouth of the fault and are character- ized by high phosphorus and high manganese.
Indian Camp mines. — These mines are a series of pits along a mile of this line. They were first operated about 1894 and at one time had narrow-gauge railway connecrtion with the Norfolk and Western Railway at Austinville. Average analyses from 4 banks, furnished by the N^^
River Mineral Company, show as follows:
Per cent.
Metallic iron 47.01
Silica 9.69
Phosphorus 1.98
Manganese 1 .23
William Jackson mm^. — Southwest of the Indian Camp mine William
Jackson, about 1898, mined some 6,000 tons of ore, which gave the X^^
River Mineral Company the following results on analysis:
Per cent.
Metallic iron 49.89
Silica 11.40
Phosphorus 1 .22
Manganese 0.85
IRON. 467
Gregory mine, — Southwest from the William Jackson mine, since 1893, the New River Mineral Company has mined some 20,000 tons, which gave the following results:
Natural State.
Per cent.
Metallic iron 35.03
Silica 20.21
Phosphorus 0.72
Manganese O.GO
In the vicinity of Ivanhoe there has heen considerable mining chiefly for the Ivanhoe furnace, which was built as a charcoal furnace in 1882. The ores are all limonite of relatively high grade and occur usually well concentrated in clay through a shallow depth.
Ivanhoe mine, — Southwest from Ivanhoe for 1.5 miles the crest and slopes of a ridge have been mined extensively. The most of this is now owned and operated by the Ivanhoe Furnace Company. The following composition of the ores has been furnished by the New River Mineral Company (column I), and by the Ivanhoe Furnace Company (column
II).
Natural State,
I. II.
Per cent. Per cent.
Metallic iron 43.92 42.00 — 44.00
Silica 16.83 14.00—18.00
Phosphorus 0.14 0.15
Mangane.se 0.73 0.40 — 1.00
Painter mine, — The north slope of this ridge and a mine north of Painter creek were operated by the Lobdell Carwheel Company.
Simmerman mines, — These mines are located a mile east of Ivanhoe. They were operated intermittently between 1890 and 1896. They consist of 5 small pits.
Sisk and Gray mines, — These mines are located 1 mile southeast of Ivanhoe on top of the precipitous bank of Xcw river. Between 1891 and 1895 the New River Mineral Company took some 25,000 tons of ore from these mines. The following composition has l)een furnished by the operator :
Natural State.
Per cent.
Metallic iron 44.36
Silica 14.79
Phosphorus 0.1 1
Manganese 0.39
458 MINERAL RESOURCES OF YIROINIA.
There has been a number of other small operations in the vicinity of Ivanhoe.
Wythe Lead and Zinc mines. — These mines, located 2 miles east of Ivanhoe, have produced a little iron ore in connection with the lead and zinc mining and now produce some ore which is the tailings from the magnetic concentrator.
Eight miles west of Ivanhoe in the vicinity of the present town of Cripple Creek there has been considerable charcoal furnace activity. Within a distance of 4 miles of each other there have been 5 charcoal furnaces. Present operations are at the head of Francis Mill creek 2 miles south of Cripple creek. The mines are in the vicinity of the contact of the limestone and the sandstone. In a kettle-shaped depression between Ilussey and Iron mountains, which carries limestone in the bottom, are located the Little Wythe and the Norma mines.
Little Wythe mine, — This mine occupies the bottom of the depression. A narrow-gauge railway connects with the Norfolk and Western Railway near Cripple Creek. The composition of this ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State,
Per cent.
Metallic iron 42.75
Silica 13.77
Phosphorus 0.25
Manganese 0.32
Norma mine. — This mine is located immediately south of the Little Wythe. It was opened in 1005. Tlie composition of the ore, as furnished by the operators, the Pulaski Iron Company, is as follows:
Natural State.
Per cent.
Metallic iron 42.05
Phosphorus 0.12
Porter mine, — This mine is a contact mine on the north side of Hussey Mountain.
There were two charcoal furnaces formerly operated near Speedwell, which used the limonite' ores. The extension of the Norfolk and Western Bailway to that point in 1906 has opened the region to shipment. The Virginia Iron, Coal and Coke Company now operates 3 mines in this Ticini^.
IKON. 469
Oanaway mine. — This mine is located i^ mile southeast of Speedwell. It is equipped with an 8-log washer and is producing 100 tons of ore per day.
Percivai mine. — ^This mine is located 1^^ miles southwest from Speed- well. It is equipped with an 8-log washer and is producing 100 tons of ore per day.
Andis mine. — This mine is located 2 miles southwest of Speedwell. It is equipped with a 5-log washer and is producing 75 tons of ore per day.
Lick Moimtain is a Valley ridge of Cambrian sandstone and shale, situated a few miles north of the New Eiver-Cripple Creek area. This has been prospected for both iron and manganese and some lump ore has been mined and hauled by wagon to Wytheville. It is reported that such mining was done during 1905.
On the north side of the Draper Mountain from Clark^s Summit to Hamilton Knob there is a line of outcrop of limestone, presumably the Valley limestone, which has the Carboniferous shales on the north side and in most places on both sides.
Clark's Summit mine. — This mine is located ^^ mile south of Summit station and at the east end of the above mentioned limestone. The mine was extensively operated by the Virginia Steel Company about 1893. The ores were then washed at the mine. It was operated in 1905 by J. M. Spriggs for lump ore.
Henson mine. — ^This mine is located on the north slope of Hamilton Knob at the west end of the limestone above mentioned. It was operated some years ago and its ores washed in a local washer, but is now abandoned.
Locust Hill mine. — This mine is located on the south side of Hamil- ton's Knob, about 3 miles southeast from Max Meadows. A narrow- gauge railway connects with the furnace at Max Meadows. The ore-bodies are from 6 to 20 feet thick and dip down the mountain with the Devonian shale. The mine was opened about 1899 and has been operated quite continuously since then. A view of this mine is shown on plate LXVIII, iigure 1. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent.
Metallic iron 37.54
Silica 18.79
Phosphorus 0.34
Manganese 1.65
4C0 MINERAL RESOURCES OF VIRGINIA.
Smyth County.
This county has a long record in the production of small quantities of iron ore. Barton's and Nichols's forges in the Rye Valley and Chatham Hill forge on North Fork of the Holston were built at the beginning of the last century. During the Civil War an attempt was made to operate a furnace, and, since the war a charcoal furnace has been in successful operation. Recently there has been some small shipments of ore. This county extends across the Great Valley. In the southern part of this valley there are anticlinal mountains of Cambrian sandstone which carry "mountain" ores. In that part of the limestone valley which lies south of these mountains "limonite" ore occurs. This is found especially on the head waters of Cripple creek and in Rye Valley. The Oriskany horizon appears in W-alker Mountain in the northern part of the county.
On the head waters of Cripple creek ore was mined between 1876 and 1904 for the ^Vhite Rock charcoal furnace. The most important of these mines are the digger, Porter, and Home banks.
Crigger bank, — This mine is located V^ mile above the junction of the upper branches of Cripple creek. It produced, between 1881 and 1885, some 25,000 tons of "limonite" ore.
Porter hank. — This mine is located in the Valley on the divide between the New and Holston rivers waters about 2 miles east of Sugar Grove. It has produced some 35,000 tons of "limonite" ore, which was washed near the mine and hauled 6 miles to the furnace. It is owned by the Lobdell Carwiu'C'l Company. This ore is high in niangane>e and carries some lead.
Home hank. — This mine is located near the furnace 5 miles southwest from Rural Rc^troat. It was mined between 1876 and 1904 and produced "mountain'' ore carrying al>out 38 per cent, metallic iron. In the Cam- brian i7ionntains west of the furnace other "mountain" ores have bten mined in a small way. at a number of ])laces.
In Rye Valley ores were mined in an early day for forges and in later time a small amount was hauled in wagons to Marion. The completion of the Clarion and Rye Valley Railway to Sugar Grove in 1903 opened this region to shi]miont. Considerable prospecting has shown ore in various places. All of these valley ores are "limonite" which is high in manganese.
In the mountains, which lie to the north of the valley, and between it and the main valley, there has been some mining. These mountains are made up of Cambrian shales and sandstones, which have been thrown into a number of closely compressed folds. Some of the synclinal vallovs between the ridges carry traces of the Valley limestone. The ores have
IBON. 463
carrying ore. Limonite ore has been mined from the clay of the Valley limestone near Tiptop in two recent operations.
Bell Hill mine. — ^This mine is located 1% miles east of Tiptop and y2 mile northwest of Springville. Ore was mined here from 1900 to 1903, washed in a local washer and hauled one mile over a narrow-gauge railway to the Norfolk and Western Eailway.
May mine. — This mine is located a mile or more west of the above mine and was operated about the same time. Lump ore only was mined, which was hauled to Tiptop.
Eussell County.
Iron ore was mined in a small way for early forges, one near Honaker and the other near Dickenson ville. In 1906 test shipments were made from the Hall mine, which is located 6 miles southwest from Castlewood. The ore is limonite and occurs in clay above the Valley limestone. The composition, as furnished by the Union Iron and Steel Company, is as follows :
Natural State.
Per cent.
Metallic iron 44.13
Silica 20.91
Phosphorus 0.17
Scott County.
This county is a Valley county. The Valley limestone is the surface rock of the greater portion of the county. The Oriskany measures appear in Clinch Mountain and probably produced iron ore in the early part of the last century for the White Forge, which was located 5 miles northeast of Moccasin Gap.
Buchanan and Dickenson Counties.
These are the two Virginia counties in which the lower measures are covered by the flat-lying Coal Measures rocks. They may have some Coal Measures iron carbonate, but the writer has no knowledge that it occurs in commercial quantity.
Wise County.
The greater part of this county has for its surface rock the Coal Measures. The southern comer of the county has Silurian measures at the surface and includes a small but important part of the fossil ore area. The anticlinal Wallen ridge carries beds No. 3 and No. 4 of fossil ore,
464 MINERAL RESOURCES OF VIRGINIA.
which are mined in the vicinity of Big Stone (Jap. There is no record of ore mining in this region till the recent coming to Big Stone Gap of the Louisville and Nashville and the Virginia and Southwestern Railways. The completion of the Union coke furnace in 1902 has made Big Stone Gap the center of the iron industry in this region.
Oreton mines. — These mines are located 3 miles south of Big Stone Gap and i^ mile south of Oreton. Kelly and Irvine are operating No. 4 on the south slope of Wallen ridge. The composition of the ore, as fur- nished hy the Union Iron and Steel Company, is as follows:
•
Natural State,
Per cent.
Metallic iron 44.90
Silica 15.81
Phosphorus 0.29
Lime 0.22
Keystone mine. — This mine consists of a series of operations north of Oreton on the south slope of Wallen ridge. The Keystone Coal and Iron Company is operating chiefly No. 3, but also No. 4.
Irondale mines. — These mines are located 2 miles south of Big Stone Gap. They are the oldest and most extensively operated mines in the district. Kelley and Irvine have operated No. 3 and No. 4 over the crest and south slope of Wallen ridge for half a mile. The composition of the ore, as furnished by the Union Iron and Steel Company, is as follows:
Natural State.
Per cent.
Metallic iron 40.14
Silica 27.98
Phosphorus 0.32
Lime 0.61
Yeary or Bnnn mine. — This mine is located immediately south of Big Stone Gap on the crest and north slope of Wallen ridge. W. E. Year}' operates No. 3. The composition of the ore, as furnished by the Union Iron and Steel Company, is as follows:
Natural State.
Per cent.
Metallic iron 42.34
Silica 18.30
Phosphorus 0.29
Liiiie 0.11
The Oriskany horizon outcrops at the base of Wallen ridge and M?at-
tered ore is found in the Helderberg limestone clay. A sample shipment
of the ore was made from Oreton.
Lee Coimty.
This county has fossil ores in Poor ^ "alley ridge and in Wallen ridge. Between 1825 and the Civil War two forges were operated in this county. These were the Milam forge, eituated on Martin's creek, near fiose Hill, and the Bowling Green, or Bales forge, situated 4 miles southeast of Eose Hill, Pennington forge at Pennington Gap was operated after the war. The only furnace of the county was the Laurel, which operated after the war. Since the building of the Louisville and Nashville Railway there has been much mining for shipment along the Poor Valley ridge. Most of these mines are located close to the Louisville and Nashville Bail- way and their (ipples deliver to the railway cars.
'■?%».^
Fig. 67. — Gpolofiit structure seotion across Poor Valley ridgu showing the relntive positions of the three beds of fOBsit iron ore.
Pennington mine. — This mine is located south of Pennington Gap and was operated in a small way for Pennington forge. The composition of the ore, as sampled from the stock pile at the forge and analyzed by McCreath in 1887, is as follows:
Metallic iron 50.50
Silica 18.75
Phosphorua 0.158
Lavine mine. — This mine is located midway between Pennington sod Ben Hur ] mile from the railway on a spur of Poor Valley ridge. A narrow-gauge railway connects with the Louisville and Nashville Railway. It is operated by Kelly and Irvine. This mine is not located on the Poor Valley monocline, which carries most of the mines of the region, but in closely folded strata situated east of the monocline. The compositton of tlie ore, as furnished hy the Union Iron and Steel Company, is as follows:
Natural State.
Per cent.
Metallic iron 43,20
Silica 22.31
Phosphorus 0.34
Lime 0.86
466 HIMEOAL RE8ODB0B6 OP TIROINIA.
Ben Hiir mine. — This mine is located on the north side of Poor Vallg ridge, west of Ben Hur station, where the railway cnts across the Poor Valley ridge. It has been mined 1,500 feet on the strike and 150 feet on the dip. The composition of this ore, as furnished by the operator, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent.
Metallic iron 34.01
Silic» 3*.60
Fhoaphorua 0.27
Manganese 0.16
Truro mme.— This mine is located southwest of Ben Hot mine, ^ of a mile northeast from Noes Siding on the north side of Poor Valley ridge. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Metallic iron 36.00
Silica 33.37
Phosphorus 0.23
Manganese 0.16
Noes Siding mine. — This mine is located southwest from Truro and % of a mile northeast from Oeoonita on the north side of Poor Vallej ridge. It is operated by Kelly and Irvine ; has been mined 325 feet on the dip. The composition of this ore, as furnished by the Union Iron and Steel Company, is as follows:
Natural State.
Per cent.
MeUllio iron 42.30
Silica 27.60
Phoaphorus 0.19
Litna 0.10
Between Noes Siding and Hagan no mining haa been done.
Grabill mine. — This mine is located 600 feet northeast of Eagm station and is operated by B. C. Grabill in a small way. The tunneU are at water-level 76 feet below the railway. The ore is hauled in wagons to Hagan.
Boones Path mine*. — These mines are located 2 miles southwest from Hagan OD the north slope of Poor Valley ridge. These mines are operated from 7 tipples along Vs '"''c of outcrop. It is the largest operation ib
the- vicinity and is operated by the Boones Path Iron Company. The G(HnpositioD of this ore, as furnished by the Union Iron and Steel Com- pany, is as follows:
|
Per cBnt. |
|
|
Metainc iron |
40 91 |
|
Silica |
10 70 |
|
Phoephonu |
0 45 |
|
UiignMia |
0 93 |
Southwest from these mines the railwaj lies on the south side of the ridge and little mining has been done along the Poor Valley between there and Cumberland Gup
Swing mine. — This mine has its tipple 1 mile east of Ewmg The mine is located 3^/^ miles southeast from the tipple and its ore is brought
Fig. 08. — Diagram of Ewmg mine {a) Shenandoah limestone (b)Clinton measures csrrjing foeeil iron ore represented bj hliick line fftulted up on the linxstonc and closely folded
to the tipple over a narrow gauge railway The mine is located m the end of a faulted a^ment of Clinton strata which have been thrust over on the Valley limestone (Figure 68 ) The beds are closely folded, contorted and fractured The ore is thm but of better grade than most of the ore of the region, carrymg lime instead of silica The composition of 26 carloads of this ore, as furnished by the operators, the Union Iron and Steel Company, is as follows :
Natttrai State.
Per cent.
Metallic iron 34.09
Silica fl.59
Phosphorus 0,58
Lime 7.72
Hagnuia 3.95
468 MINERAL RESOUBOES OF VIROINIA.
PISDXOHT COUNTIES.
The counties treated below under this head lie east of the western range of the Blue Eidge. Their rocks are chiefly crystalline schists, the most of which are probably metamorphosed sedimentary rocks. These for tiie most part have been more or less closely folded with the axes of the folds striking northeast and southwest. As the result of this the outcrop of a given formation usually strikes in the same direction. The schistodty usually dips at high angles to the southeast. The ore-bodies usually follow either the bedding or the schistosity and in either case usually dip et high angles. The ores are mostly magnetite, specular hematite, and limonite. The limonite is usually the gossan of a sulphide. In the northeast this sulphide is usually pyrite, with the pyrite sometimes gold- bearing, so that gold mines and iron mines are associated. In the souih- M'est much of the sulphide is pyrrhotite. As the pyrrhotite usually carries some chalcopyrite the iron mines of the southwestern Piedmont counties are usually associated with copper mines. A comer of Bedford county carries some of the Blue Bidge hematite. In general the counties forming the two most northeasterly tiers of the Piedmont carry iron ore while the other Piedmont coimties do not.
Loudoun County.
Iron ore was mined in this county for the Potomac furnace, which was built in 1839. The ore was limonite and was mined near the furnace, a short distance below Point of Bocks.
Stafford County.
On the property of Augustine Washington, the father of George Washington, iron ore was mined about 1727 for the Accokeek furnace. This furnace was abandoned in 1753. However, this was not for want of ore, as the mine was considered capable of supplying another furnace in Eevolutionary War time. There ig no known record of any iron ore mining in this county subsequent to 1753.
Spottsylvania County.
This county carries a strong development of pyrite through the norfli- westem side. The gossan cap of this was early worked for charcoal furnaces. The first furnaces were those of Governor Spotswood. The Germania, located in the northern corner of the county near the Rappa- hannock river, was built about 1714. This was the first furnace in the
IKON. 469
South and the first furnace in America to produce pig iron. The other Spotswood furnace, built about 1827, was located in the southwestern part of the county about a half mile from the North Anne river. The Catherine furnace was located about 3 miles west of Chancellorsville. For many years ore was mined at a number of places scattered through the territory between this furnace and the Kappahannock river.
Lonisa Conjity.
Near Mineral City pyrite is now mined. A description of these mines is given under Pyrite on pages 198-202. The gossan from these pyrite deposits was mined for the Victoria and the Rough and Ready charcoal furnaces in the middle of the 19th century. Magnetite was mined for the latter furnace from two mines near the furnace.
Albemarle County.
This county has pyrite gossan. Old^s furnace, located 12 miles from Charlottesville, was an old furnace in Revolutionary War time. Pre- sumably it used a gossan ore.
Stony Point mine. — Near Stony Point, some 6 miles northeast of Charlottesville, at the northwest base of Southwest Mountain, gossan has been extensively worked in modem times. It is reported that between i878 and 1886, 2,600 carloads of iron ore were shipped from here to Pitts- burg furnaces. As stated under Copper, pages 502-503, there is a continuous outcrop of ore for % of a mile with widths of from 5 to 6 feet, and it has been mined to a depth of 130 feet. The gossan is imderlain by some chalcopyrite and the mine has produced some copper. At North Garden magnetite and limonite have been mined. An analysis of the North Garden ore, as made for the Tenth Census report, gave :
Per cent.
Metallic iron 46.69
Phosphorus 0.066
Nelson County.
Oreenway mine. — Specular hematite was mined in 1880 in the southern comer of the county at the Greenway mine, located 2^ miles west of Oreenway. It is said to have been mined to a depth of 200 feet for a length of 500 feet with widths up to 12 feet. An analysis made for the Tenth Census gave as follows:
Per cent.
Metallic iron 63.02
Phosphorus 0.049
470 MINERAL RESOURCES OF VIRGINIA.
At Roseland there are extensive deposits of phosphatic titaniferous iron rock. This has been extensively prospected but not mined as an iron proposition. A further account of this is given under Hmenite and Phosphates, on pages 232 and 300-301.
Buckingham County.
Limonite ore was mined in this county before 1840 for the Bear Garden furnace near New Canton on the James river. The ore was the gossan of a pyrite lead. Professor Sogers reports, "About a mile east of WTiispering Creek, nearly in line with Willis Mountain, a hieavy bed of magnetic oxide crosses the road leading from Maysville to Ca Ira. and may be traced for some distance in a northeast-southwest direction. It is fram 6 to 8 feet in width.''
Mecklenburg County.
The magnetic and specular ores, which occur in Granville county, North Carolina, are reported to extend northeastward into Mecklenburg county, Virginia.
Amherst County.
Elk creek charcoal furnace was operated in the eastern comer of this county in the first half of the 19th century on local magnetic and limonite ores. About 1880 these ores, particularly the magnetite and specular hematite, were zealously exploited. Near Elk creek furnace a 3-foot thick- ness of specular ore was prospected, which, according to the Tenth Census
report, carried:
Per cent.
Metallic iron 38.42
Phosphorus 0.118
Within a mile of this limonite ore was mined which, according to the
Tenth Census report, carried:
Per cent.
Metallic iron 44.54
Phosphorus 0.85
Riverville mines, — These mines, located within 2 miles of Riverville west and north, consisted of a number of operations in specular an^ magnetic ore, which lay in beds in widths up to 16 feet, dipping at high angles, and were associated with quartzite and mica shist. Mining was carried to a depth of about 100 feet. No. 10^^, sampled across a breast of 16 feet, gave the Tenth Census analyst:
Per cent.
Metallic iron 40.51
Phosphorus 0.096
IRON. 471
No. 11 of Adams^ Scott & Co., with a thickness of 4 feet, gave the Tenth Census analyst :
Per cent.
MetalUc iron 39.76
Phosphorus 0.126
No. 11 of the Dover Company, with a thickness of 3 feet, gave the Tenth Census analyst :
Per cent.
Metallic iron 48.47
Insoluble 28.53
Phosphorus 0.10
Sulphur 0.36
Maud vein. — Near Stapleton the Maud vein, a mine similar to the IJiverville mines, worked for a distance of 900 feet and to a depth of 80 feet with a width of 3 feet, gave the Tenth Census analyst:
Per cent.
Metallic iron 49.89
Phosphorus 0.139
Appomattox County.
Appomattox had a number of ancient charcoal furnaces which were located in the northwestern part of the county near the James river. Of these the Stonewall was one of the more recently operated. These furnaces used chiefly the limonite ores of the region. It is not known that these ores have been operated in recent times. They were prospected at the time of the boom in the James river region in the early SOs.
Campbell County.
The Ross furnace, located 2 miles south of the present James river bridge, is one of the oldest furnaces in the region. In 1781 Jefferson repori:s that it was making 1,600 tons of pig iron annually. Under the name of Oxford furnace it was operated in Civil War time. Its chief bank is located a few hundred yards northeast of the furnace site. The mine was a deep open cut located on top of one of the higher elevations of the region. The ore is limonite. At present fine manganese ore is being mined in quantity on the strike of the old iron ore-body and only a couple hundred yards distant. It is reported that ore was shipped from Lawyers in the 80s.
Bedford County.
While Bedford county is a Piedmont county, a small comer of the county extends into the Blue Ridge and it carries an important develop- ment of the Blue Ridge hematite ore. From the Botetourt county line
472 MINERAL RESOURCES OF VIRGINIA.
northeastward for a distance of some 2 or more miles this ore has been worked on the southeast slope of the Blue Ridge. Most of the operatioM have been small excavations on the outcrop of the bed. Present mining consists of extensive underground operations in which the bed has been entered at the more favorable points where ravines cut it.
Ironville mine. — This mine^ located V^ mile north from Ironville, was first opened in 1879. It has been operated at various times since. Present workings extend several hundred feet on the strike and through 200 feet on the nearly vertical dip of the bed. The ore is hauled in wagons to Ironville. The composition of the ore, as furnished by the Virginia Iron, Coal and Coke Company, is as follows:
Natural State,
Per cent.
Metallic iron 34.66
Silica 39.06
Phosphorus 0.39
Manganese 0.15
Dewey mine, — This mine was opened more recently than the Ironville but has been more extensively worked. It is located immediately north- east of the Ironville mine and the underground workings of the two mines are said to connect. The main workings now operated are drifts on the nearly vertical bed for a distance, said to be 1,500 feet, through 6 or 7 levels nearly up to the original outcrop workings. The ore bed is said to vary in thickness from 3 to 12 feet. Recently at two places at this mine operations have been started in sinking on the bed below water level. The ore-body has been somewhat folded and in places is said to be shifted a few feet by faulting. A narrow-gauge railway some 3 miles long con- nects the mine with the tipple near Montvale. The composition of the ore, as furnished by the oi)erator8, the Virginia Iron, Coal and Coke Company, is as follows :
Natural State,
Per cent.
Metallic iron 36.90
Silica 34.86
Phosphorus 0.28
Manganese 0.23
Pittsylvania County.
Pittsville mine, — An important deposit of magnetic iron ore occurs near Pittsville in the northwestern part of the county. This ore was first mined about 1880 by the Pig River Mining Company, which is
' ' • I
'C
MINi:rtAI. KKHCM'UrKH OK VIKGIMA
■ Pittsvill?. Pitt-yl-
Fig. a.— llHrr liiixiiiito mine, iipar I'itt-viU,.. rittKylvaiiia ,01111 lElOX MINKS. IMTTSVI.VANI.X (XHNTY. VIRCIKIA.
473
reported to have mined 90,000 tons. The ore is fine-grained to masBive magnetite. The lead is quite variable in both etrike and dip. It has been mined for a half mile of its length. These workings are reported to have an average width of about 3 feet and were mined to a depth of 150 feet. A sample taken across the face of the lead and analyzed for the Tenth Census gave as follows :
Natural State.
Per cent.
MeUllic iron SS.BS
Phoephorus 0.00
Barr Magnetite mine. — J. H. C. Bair has mined the extension of the lead of the Pittsville mine since 1806. The lead here lies bctweeu walls
Fig. 89. — Section in the Barr magnetite mine, showinfj relation of the ore to the adjacent formations, (a) Mica schist, (b) Magnetite, (c) Umi>er- bearing day. (d) Space, (c) CryBtalline linip-
of qnsrts schist and crystalline limestone. (Figure 69.) The lead here has conaiderBbly greater widths than is reported for the Pittsville mine and has been worked to a somewhat greater depth. A view of the shaft hooae at this mine is shown on plate LXX, figure 1. The composition of the ore, as given by the operator, is as follows :
Metallic iron 84.25
Silica 4.62
PbiMphonu 0.008
Barr lAmon^t mine. — Two miles from the Barr magnetite mine the flame operator is mining limonite ore. It is washed in a local washer and
474 MINERAL RESOURCES OF VIRGINIA.
delivered over a narrow-gauge railway to Pittsville. Massive outcrops of limonite occur along the crest and slopes of a ridge for half a mile. Where mined the ore is massive or as closely spaced stringers in clay. A view of this mine is shown on plate LXX, figure 2. The composition of the ore, es furnished by the operator, is as follows :
Per cent.
Metallic iron 47.00
Silica 12.25
Phosphorus 0.85
Manganese 2.70
in County.
Gossan was mined in this county near the Floyd county line a few miles northeast of the Toncray mine for an early local furnace. Magnetic ores of importance occur in this county. H. B. C. Nitze traced the mag- netic lead from Rocky Mount, Franklin county, southwestward 24 miles to Stewart's Knob in Patrick county.
Rocky Mount mine, — The ore at Rocky Mount was mined at an early date for the Saunciers' furnace. In 1880 these ores were mined by the Pig River Mining Company and shipped to Pennsylvania. The ore is a fine-grained pure magnetite with walls of dense hornblende schist dipping 60° southwest. A sample taken at a depth of 20 feet across the 9-foot working face of the mine for the Tenth Census gave as follows:
Natural State,
Per cent.
Metallic iron 53.59
Silica 14.67
Phosphorus 0.018
Manganese 0.12
Titanic oxide none
Sulphur 0.36
Patrick County.
A part of the magnetic lead which extends southwest through Franklin county is found in Patrick. Ore was mined at the Hairston mine for the Union furnace.
Hairston mine, — This mine is located at Stewart's Knob in the north- western part of the county. In 1906 a narrow-gauge railway was con- structed from Philpot to the mines a distance of 12 miles for the purpose of furnishing an outlet for these ores. The ore is magnetite, similar io that at Rockv Mount, and occurs in a number of leads which are from 3 to 6 feet wide and associated with hornblende schist. It is operated by
IRON. 475
the Virginia Ore and Lumber Company. An average of 10 analyses, made by Mr. W. W. Davis from samples taken by him for a private report, shows as follows:
Natural State.
Per cent.
Metellic iron 59.93
Silica 7.72
Phosphorus 0.08
Manganese 0.17
Sulphur 0.19
Henry County.
Nitze says that the magnetic ores which occur near Danbun;, Stokes county, North Carolina, extend into Henn- county, Virginia.
Floyd County.
Toncray mine, — Gossan was mined in the southwestern part of this county on the West Fork of Little river at the. Toncray mine for the Shelors and West Fork furnaces. In the northeastern part of the county pyrrhotite and pyrite occur which are reported to carry nickel in minable percentages. (See pages 580-582 for a further account of this sulphide.) The county is without a railway and there have been no modern iron ore operations.
Carroll County.
This county contains the greatest development of the "gossan lead." Gossan ore was mined for two or more forges on Chestnut creek. At two points in this county the *^ead" has been crossed by a railway and gossan has been extensively mined at both places.
Chestnut Yard mines. — At Chestnut Yard the gossan has been mined out for several miles along the lead. At the "Great Outburst," which is a part of the Chestnut Yard operations, the lead from which the gossan has been removed is 175 feet wide. At this point pyrrhotite ore, "mundic," is now being mined for the acid plant at Pulaski by the Pulaski Mining Company. Plate XXX is an illustration of this mine.
An analysis of "mundic" from the "Great Outburst," furnished by the New Eiver Mineral Company, is as follows:
Per cent.
Metallic iron 57.26
Insoluble 3.68
Sulphur 38.61
Copper 0.82
Manj^anese 0.19
476 MINERAL RESOURCES OF VIRGINIA.
After this sample was burned as completely as possible over a blast lamp
it gave as follows:
Per cent.
Metallic iron 60.40
Sulphur 1.64
Betty Baker mine. — At Betty Baker mine the gossan was mined between 1889 and 1902 for a mile along the lead where it had a width of from 10 to 30 feet. The composition of the ore, as given by the operators, the Virginia Iron, Coal and Coke Company, is as follows:
Natural State.
Per cent
Metallic iron 36.15
Silica 16.36
Phosphorus 0.12
Manganese 1.40
Magnetic ores are reported in this county, but the writer has no
knowledge that they have been worked.
Orayson County.
Gossan ore was mined in this county for the Pine Hope furnace, located 3 miles southeast from Independence. Scattered outcrops of the northern "gossan lead*^ are said to occur in this county westward from Chestnut Yard. Magnetic ore is known in this county. It is reported that such ore was mined near Independence for the Pine Hope forge. Near Fries magnetic ore has been prospected and it is reported that some was used in the Chestnut forge. Magnetite ore is reported near the Mouth of Wilson on the State line. A sample from the Pugh prospect a half mile south of the State line gave on analysis the following results, re- ported by Nitze:
Per cent.
Metallic iron 46.44
Silica 22.74
Phosphorus 0.022
Sulphur 0.049
Near the point where Little Helton creek crosses the State line titan-
iferous magnetite has been prospected with a good showing. A sample
from the 25-foot Young outcrop a quarter of a mile south of the State
line gave an analysis, reported by Nitze, as follows:
Per cent.
Metallic iron 60.77
Silica 6.12
Phosphorus 0.006
Sulphur 0.04
Titanic oxide 4.95
IBOK.
477
A titaniferous magnetite in a hornblende schist is reported in the south- east comer of the county. This ore was worked about 1886 just south of the State line for the Collins forge. An analysis of this ore, as given
by Nitze, is as follows:
Per cent.
Metallic iron 54.72
Silica 6.20
Phosphorus 0.047
Sulphur 0.038
Titanic oxide 4.86
COASTAL PLAIN COXTHTIES.
These counties in Virginia have not been producers of commercial iron ore. In 1609 the colonists mined some ore which was taken to England and there made 16 tons of metal. The iron works at Falling Creek, in the present Chesterfield county, which were built between 1619 and 1622, were to run on local ores. These works were destroyed by the Indians in 1622. Since that time it is not known that there has been any iron mining in these counties. In both North Carolina and Maryland iron ore has been rained from strata similar to those which constitute the Virginia Coastal Plain. In Maryland the ore is carbonate which occurs in lumps scattered through clay in layers, and has been extensively mined.
List of Iron Mines in Virginia.
In the list appended below are included those mines that are now pro- ducing or have produced in the last two years, or have been recently pros- pected and will probably shortly become producers.
|
Name of mine |
County. |
Kind of |
ore. |
Operator. |
|
Big Ike |
Warren |
Blue Ridge |
limonite |
F. G. Grove |
|
Happy Creek |
Warren |
Blue Ridge |
limonite |
H. J. Seibel, Jr. |
|
Liberty |
Shenandoah |
Oriskany |
Shenandoah Iron and Coal Co |
|
|
RileyvUle |
Page |
Blue Ridge |
limonite |
|
|
Black Rock |
Augusta |
Blue Ridge |
limonite |
The Vesuvius Mining Co. |
|
Bare Bank |
Augusta |
Blue Ridge |
limonite |
|
|
Grozier |
Augusta |
Blue Ridge |
limonite |
|
|
Buena Vista |
Rockbridge |
Blue Ridge |
limonite |
Buena Vista Iron Co. |
|
Dixie |
Rockbridge |
Blue Ridge |
limonite |
Alleghany Ore and Iron Co. |
|
Rumsey |
Alleghany |
Oriskany |
Low Moor Iron Co. |
|
|
Dolly Ann |
Alleghany |
Oriskany |
Low Moor Iron Co. |
|
|
Longdale |
Alleghany |
Oriskany |
Longdale Iron Co. |
|
|
Fancy Hill |
Alleghany |
Oriskany |
Longdale Iron Co. |
|
|
Stack |
Alleghany |
Oriskany |
Low Moor Iron Co. |
|
|
Hone Mt. |
Alleghany |
Fossil |
Low Moor Iron Co. |
|
|
Rich Patch |
Alleghany |
Oriskany |
The Goshen Iron Co. |
|
|
Bess |
Alleghany |
Oriskany |
Low Moor Iron Co. |
|
|
Double Ridge |
All^any |
Oriskany |
Low Moor Iron Co. |
|
|
Sand Bank |
Botetourt |
Oriskany |
Princess Iron Co. |
|
|
Gallie |
Botetourt |
Oriskany |
Princess Furnace Co. |
|
|
Wilton |
Botetourt |
Oriskany |
Princess Furnace Co. |
478
MINERAL RESOUBOES OF VIRQIKIA.
Name of mine. County.
Circle
Oriskany
Grubb
Griibb Specular
Edith
Arcadia
Wood
Fenwick
Rorer
Porterfleld
Tasker
Farris
Rich Hill
Reed Tsland
Clayton
Peak Knob
Barren Springs
Bertha
Cedar Run
Sanders
Morris
Hurst
Patterson
Crawford
Tipton
Foster Falls
Hematite
Posey
Poplar Camp
Ivanhoe
Little Wythe
Norma
Ganaway
Percival
Andis
Clark Summit
Locust Hill
Slemp Creek
Holston
Taylor's Valley
Hall
Oreton
Keystone
Irondale
Yeary
La vine
Ben Hur
Truro
Noes
Grabill
Boones Path
Ewing
Chestnut Yard
Hairston
Barr
Barr
Ironville
Dewey
Botetourt
Botetourt
Botetourt
Botetourt
Botetourt
Botetourt
Botetourt
Botetourt
Roanoke
Giles
Pulaski
Pulaski
Pulaski
Pulaski
Pulaski
Pulaski
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Wythe
Smyth
Washington
Washington
Russell
Wise
Wise
Wise
Wise
Lee
Lee
Lee
Lee
liCe
Lee
Lee
Carroll
Patrick
Pittsylvania
Pittsylvania
Bedford
Bedford
Kind of ore.
Oriskany
Oriskany
Blue Ridge liroonite
Blue Ridge hematite
Blue Ridge hematite
Blue Ridge hematite
Blue Ridge hematite
Oriskany
Blue Ridge limonite
Limestone magnetite
"Mountain ore"
"Mountain ore"
Limestone limonite
Limestone limonite
Oriskany
Oriskany \
Limestone limonite
Limestone limonite
Limestone limonite
Limestone limonite
"Mountain ore"
"Mountain ore"
Limestone limonite
Limestone limonite
"Mountain ore"
"Mountain ore"
Limestone limonite
Limestone limonite
"Mountain ore"
Limestone limonite
Limestone limonite
"Mountain ore"
Limestone limonite
Limestone limonite
Limestone limonite
"Mountain ore"
Oriskany
"Mountain ore"
Magnetite
"Mountain ore"
Limestone limonite
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Fossil
Pyrrhotite
Magnetite
Magnetite
Limonite
Blue Ridge hematite
Blue Ridge hematite
Operator.
Longdale Iron Co. Alleghany Ore and Iron Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. G. G. Harvey Low Moor Iron Co. Virginiii Iron, Coal & Coke Co.
West End Furnace Co Pulaski Ir<m Co. Virginia Iron, Coal & Virginia Iron, Coal & Pulaski Iron Go. Hatcher and Shaffer Hagar and Mahady Virginia Iron, Coal & Pulaski Iron Co. Virginia Iron, Coal & Virginia Iron, Coal & Virginia Iron, Coal & Virginia Iron, Coal & Pulaski Iron Co. Virginia Iron, Coal & Pulaski Iron Go. Virginia Iron, Coal & Virginia Iron, Coal & Virginia Iron, Coal & Pulaski Iron Co. Ivanhoe Furnace Co. Virginia Iron, Coal k Pulaski Iron Co. Virginia Iron, Coal & Virginia Iron, Coal & Virginia Iron, Coal & J. M. Spriggs Virginia Iron, C-oal &
Coke Co. Coke Co.
Coke Co.
Coke Co. Coke Co. Coke Co. Coke Co.
Coke Co.
Coke Co. Coke Co. Coke Co.
Coke Co.
Coke Co. Coke Co. Coke Co.
Coke Co.
Ivanhoe Furnace Co.
Taylor's Valley Iron Co.
M. A. Hall
Kelley and Irvine
Keystone Coel and Iron Co.
Kelley and Irvine
W. E. Yeary
Kelley & Irvine
Virginia Iron, Coal & Coke Co.
Virginia Iron, Coal & Coke Co.
Kelley and Irvine
B. C. Grabill
Boones Path Iron Co.
Union Iron and Steel Co.
Pulaski Mining Co.
Virginia Ore and Lumber Co.
J. H. C. Barr
J. H. C. Barr
Virginia Iron, Coal & Coke Co.
Virginia Iron, Coal & Coke Co.
IBON.
479
List of Fnmaces in Virginia.
Name.
Alleghany
Bristol
Buena Vista
Crozier No. 1
Crozier No. 2
Dora
Gem
Graham
Ivanhoe
Longdale No. 1
Longdale No. 2
Low Moor A.
Low Moor B.
Covington
Max Meadows
Princess
Pulaski
Radford
Radford-Crane
Union No. 1
Victoria
West End
Annual capy. Place. Comity. in tons.
Coke Fumaoes,
Operator.
Iron Gate
Bristol
Buena Vista
Roanoke
Roanoke
Pulaski
Shenandoah
Graham
Ivanhoe
Longdale
Longdale
Low Moor
Low Moor
Covington
Max Meadows
Glen Wilton
Pulaski
Radford Furnace
Radford
Big Stone Gap
Goshen
Roanoke
Alleghany Washington Rockbridge Roanoke ) Roanoke 3 Pulaski Page Tazewell Wythe Alleghany Alleghany Alleghany Alleghany Alleghany Wythe Botetourt Pulaski Pulaski Montgomery Wise
Rockbridge Roanoke
30,000 50,000 54.000
100,000
50,000 36,000 40,000 25,000
40,000
100,000
60,000 15,000 55,000 4,000 50,000 50,000 50,000 48,000
Alleghany Ore and Iron Co. Virginia Iron, Coal & Coke Co. Alleghany Ore and Iron Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Alleghany Ore and Iron Co. Virginia Iron, Coal & Coke Co. Ivanhoe Furnace Co. The Longdale Iron Co. Low Moor Iron Co.
Ix)w Moor Iron Co. Low Moor Iron Co.
Virginia Iron, Coal & Coke Co. Princess Furnace Co. Pulaski Iron Co. Richard Wood
Virginia Iron, Conl & Coke Co. Union Iron and Steel Co. The Goshen Iron Co. West End Furnace Co.
Virginia Iron, Conl & Coke Co. Shenandoah Iron and Coal Co. Virginia Iron, Coal & Coke Co. Lobdell Carwheel Co.
Charcoal Furnaces. Foster Falls Foster Falls Wythe 3,000
Liberty Liberty Furnace Shenandoah 25,000
Reed Is. Boom Reed Island Pulaski 3,000
White Rock Rural Retreat Smyth 2,500
Electric Furnaces.
Holcomb Rock llolcomb Rock Bedford 2 furnaces Willson Aluniinuni Co. Total number of blast furnaces 26, of which 22 are coke and 4 are charcoal. These furnaces produced in 1906, 483,525 long tons of pig iron.
Methods of Mining.
Iron ore occurs in Virginia in a variety of different ways. These different modes of occurrence demand different methods in mining. The chief methods in open cut mines are steam shovel mining, milling, sluicing, hydraulicing, and pick-and-shovel mining.
The steam shovel is extensively used in mining limonite ore in Vir- ginia. It is most used in the New River-Cripple Creek district, but also used on the Blue Ridge and Oriskany ores. In the first mentioned district where it is necessary to move large quantities of lean clay the steam shovel is particularly adapted. This method is not used to advantage where the clay is thin, where there are many limestone horses in the ore, or where the ore-bodies are scattered. In the Oriskany district much ore lies covered by not more than 20 feet of soft rock. This overburden is removed
480
UIHBSAL &E80DKCEB OF VIRQINU.
by steam shovel and then the ore itself lifted by the same meaoB. Here the more solid ore requires blasting before the shovel can move it. The ehoYels are mounted on broad- or narrow-gange railway tnickfl and deliver to cars operated on a. parallel track. Plate LXIV, figure 1, and plate LXYII, figure 2, illustrate the use of the steam shovel in mining.
Milling is shown in plate LXVIII, figures I and 2, and in figures 70, 71, and "Z below. The process consists essentially of caving the material ot the bank directly to cars. The material of the bank is loosened by hand with the pick and allowed to roll down the steep slope to the can. The cars are placed in position to receive the material by head- ing them into tunnels. Com- monly the tunnels are short, merely long enough to receive one or two carB, and the ore is milled down the outer slope. The tunnel may be longer and then a shaft is driven from above to meet the end of the tunnel and the ore milled dovm the abaft. This latter method is not much used, as it involves extra work in handling ears. Ifilling \9 a cheap mtthod of mining and ia extensively used in the New Eiver-Cripple Creek region. It is serviceable where the minable material is of sufficient thicknesB and where the overburden ia not too great. It can be used in confined situations where a steam shovel cannot.
Sluicing is a method of mining in which the material of the bank is loosened usually by hand with a pick and allowed to roll down a slope (he same as in milling. The water is pumped through 6-inch or larger iron pipes to the summit of the mine. It is allowed to pour through (brt ditches to the point at which it receives it« load and from there conducted in iron troughs to the washer. This method of mining is used in the Ne* River-Cripple Creek region. It is usable in mining ore-bearing clavs vyhere there is a slope of one to eight between the mine and the washer and where water is available. It can be used in more confined situations than either the steam shovel or milling and baa the advantage over thee methods that the material arrives at the washer in excellent cooditioD for washing.
WM///M
IBON. 481
HydranlJcing is the method of mining in which a stream of water from a nozzle is directed against the bank with Bufficient force to tear down the bank The broken down matenal is carried by the spent water through sluice troughs to the washer The water is pumped to the mme the same as in sluicing while at the mine a second pump forces the water through
K'/y/7'///7/////,
'/^v///m
the nozzle This method is used in several mines in the New Birer- Cnpple Creek region It is usable under conditions similar to those required by sluicing but is not as usable in such confined situations. Plate LXIX, figures 1 and 2, illustrate this method of mining.
Pick-and-ehovel mining of ore-beanng clay is expensive and is used only as a last resort It finds its chief application in rich, shallow deposits
482 MINERAL RESOURCES OF VIRGINIA.
where other methods are not available. It is also used in confined situa- tions on the richer portions of deposits which have been mined mamly by the cheaper methods. Pick-and-shovel mining in rich lump ore and in solid ore is not so expensive and is much used. For lump ore it is used in prospects where the quantity of wash ore is doubtful, in mines which have been abandoned as not producing sufficient wash ore to maintain a washer, and in deposits which contain both lump and wash ore but contain too little of the latter to maintain a washer. In these cases the lump ore is separated from the clay and fine ore by screening with a wire screen of about one inch mesh. Surface occurrences of solid ore are much mined by pick-and-shovel. This applies to massive limonites, gossan, and to the outcrop of fossil and Blue Ridge hematite. All of these are so solid that drilling and blasting are required.
Underground mining has to deal almost entirely with massive ore. Ore-bearing clays such as are mined by open cut methods in the New River-Cripple Creek region will not bear the expense of underground mining. Many of the deep-seated limonites have associated clay, but the limonite usually constitutes more than one-half of the material mined. The methods used in mining these ores vary with the character of the ore, with the shape, size, and attitude of the deposit, and with the character of the enclosing rock.
The Valley limonites are rarely mined underground. The limonites of the Blue Ridge are mined underground to some extent. As these deposits are of irregular shape and extent, systematic methods are not readily applied to the mining of them. They are mined in shaft and tunnel in the method best adapted to the individual deposit.
The Oriskany ore, in general, has a fairly constant thickness and attitude in any given mine and can be mined systematically. Most of the ore-bodies so far mined dip at high angles. In raining such deposits several parallel horizontal tunnels are usually run one above the other along the strike of the deposit in the ore. The lower tunnel is used as a main car level and serves for most of the lateral transportation of the ore. The upper tunnel is located near the upper limit of the ore. Most of the ore is mined near the top of the ore-body in robbing rooms which are 10 to 12 feet hisrh. As the ore is removed timbers are set so as to support the debris above. When a room of sufficient size has been created, timbers are laid horizontally on the floor of the room and covered with smaller cross timbers. When the vertical supports are broken by blasting, the debris from above sinks to the floor and the horizontal timbers, previously placed, are in position to serve as caps for the supports in the room which is to
483
be excavated andemeath. The ore as mined is thrown down ahoota to a car level. The car levels usually extend horizontally to the surface bnt in greater depths ore may be lifted in a vertical shaft. Figure 73 iUns- trates this method. Most of the limonites are so solid as to require constant drilling and blasting. Several mines are equipped with air drills. In many of the mines the natural cireulation of the air in the mine is
to the adjacent formatioiu,
sufficient for ventilation but in the more extensive and complex mines a forced circulation is produced by means of fans.
The outcrop of the hematite of the Blue Ridge has such abrupt and continuouB changes of elevation that it is mined to a considerablo depth as a surface working. At greater depths methods similar to those osed in the Oriskany ores are used. The problem here is however much nrnpl^. The ore-body is usually nearly vertical with good walls of com- pact shale or strong sandstone. Comparatively little timbering is necessary
484
MINERAL RESOURCES OF VIROIKIA.
and it is not necessary to support the debris from above. In the foeeil hematite the ore-beds may be flat-lying or dipping at angles tip to nearly vertical. These beds are mined in thicknesses varying from 16 inches up to 4 feet. The thinness of the beds makes mining a more difScnlt problem than the mining of the Blue Bidge hematite. The similarity of these beds to coal beds makes the methods of coal mining applicable to the mining of this ore. The room-and-pillar method is generally used. The methods vary considerably with the dip of the strata. With a dip of a few degrees and a relatively light overweight, parallel entries are driven in the ore about 46 feet apart and wide enough for the small entry cars. From these entries 16-foot wide rooms are turned off at right angles to
Fig. 74. — Diagram illustrating method of mining in steeply dipping beds of fossil iron ore.
the entries leaving 40-foot square pillars. When the entries have been extended as far as desired the pillars are robbed beginning at the inner end. Where the size of the pillars is properly adjusted to the overweight, the back edge of the pillar will be crushed by the overweight and render blasting unnecessary. Figure 74 illustrates this method. Where the ore bed is dipping at a high angle, a car level is run in the ore nearly <hi the horizontal. From this stopes are turned off about 34 feet apart, a few feet wide below but widening above to 30 feet and leaving b^een adjacent stopes 4-foot pillars. Ore is won chiefly by blasting from the upper end of the stopes. This delivers ore to the car below without further handling. When the stope has reached upwards not more than 100 feet the 4-foot pillars are iMmi back. Figure 75 illustrates this method. In these steei^y dipping beds flie cm is easier mined than in the flat-lying beds
J
486
and j-pn be mined in smaller thickneaaes. In the flat-lying beds the cheap ' ore ia won from the pillara, while in the steeply dipping beds the cheap or* . is won from the Btopes. Most fosail hematite contains some portioBtrf the bed which is so soft that it can be bored with some hand-power aug« drill.
Fig. 75. — Diagram illustrating method of mining in tlat-lf ing beds of fossil
Ore Dresung.
Host iron ores mined in America are sent to the furnacG as mined. As moat of the Virginia iron orea are limonite, and as most of this occurs saaociated with clay it requires treatment before it can go to the furnace. In the limestone limonitea the limonite conatitutee from 3 to 35 per cent. of the total material of the bank. It ia, then, obvioualy necessary to handle from 4 to 30 tons of material to get one ton of ore. lo the Otiekany ore the limonite usually eonetitutes over half of the material mined. In the Bine Ridge limonites the limonite usually constitutea a r per oent. of the material mined than in the Oriskany ores. Some
486 MINERAL RESOURCES OF VIRGINIA.
limonite ores have associated with them also in addition to the clay, silica in the form of flint, chert, quartz sand, or quartz crystals.
To remove the clay, log washers are used. A log washer consists essentially of an axis mounted in a gently sloping trough and having arms spirally arranged about the axis. The logs are usually mounted in pairs and revolve in opposite directions. The material to be washed is delivered to the logs from above well down toward the lower end while a stream of water enters at the upper end. The revolving logs agitate the material and deliver the ore to the upper end while the water carries the clay in suspen- sion out at the lower end. Where the material washed contains sand, gravel, or flint this material is delivered with the ore. Sand is removed from the ore by a revolving screen, mounted so as to receive the heads from the washer. Where there is much coarse flint or mud balls, the sand screens are made to discharge to picking belts, tables, or inclined troughs where this objectionable material is removed by hand. Where there is considerable line flint or gravel which is removed neither by the sand screen nor by hand picking, jigs are used. The separation by the jig depends on the different specific gravities of the ore and the objectionable material. In the process of jigging the sized material is delivered to screens where it is acted on from below by pulsing water which carries off the lighter material at a higher elevation than that at which the heavier ore is discharged. Jigging is a relatively slow and expensive process compared with washing. It is not used at most of the washers in Virginia.
In charcoal furnace days the limonite was usually roasted before it was sent to the furnace. The roasting was commonly done in open heap? which were formed of alternate layers of waste charcoal and ore. Rarely special kilns were used in which to roast the ore. In modern practice the ores are not roasted either for coke or charcoal furnaces.
Uses.
Iron ore is used chiefly for the manufacture of the metal iron. This use consumes all but a small quantity of the iron ore mined. Used for this purpose, the blast furnace produces pig iron from the ore. Of the pig iron thus produced in the United States in 1904, 84 per cent was converted into steel. Iron ore is also used for paint, for fix or fettling in puddling furnaces and as flux in smelting the precious metals.
|
Amoant. |
Vilue. |
||||||||
|
S|- |
1 |
Rinds. |
Per ton at |
||||||
|
1 1 |
?^-» |
||||||||
|
1 ; |
fl= |
S^ |
1 i |
||||||
|
'' 1 |
«„? |
Total. ! |
|i |
i ' |
|||||
|
ill 14 = |
■s«a r-i III |
1 Ii| i 'ill |
i |
1 |
1 \ > 1 |
||||
|
j»». |
Ra«t |
||||||||
|
! |
|||||||||
|
! ' « |
67,310 23,217 . •47,168 |
$158,307 |
|||||||
|
1 11 |
|||||||||
|
12 |
1.6 |
j 108,268 |
2.18 |
..';" |
|||||
|
i;"!;. ...^.. [;::::; |
' 'z.'i |
aim |
" 37',bbb |
"i" |
ii&,'246 |
ib;645 |
384',33i |
' 2. 36 |
..... '■2.» |
|
■-y |
"a 4' |
' 498,Vm |
8,746 |
"2 |
"m.m |
rt'WHl |
"m,m |
"i.93 |
"'2.30 |
|
643.683 668,916 |
|||||||||
|
« |
4.fi |
3:274 |
1 |
653,342 |
2.300 |
||||
|
7 |
4 fi |
741,027 |
26,120 |
1 |
711,753 |
3,15-1 |
1,428,801 |
1.91 |
2.04 |
|
6 |
n 3 |
t61 6,966 |
41,665 1 1 |
668,800 |
6,500 |
1,060,977 |
1 7f |
1.66 |
|
|
fi.i |
t600,662 |
35,843 |
602,493 |
2,226 |
873, 30{ |
1 4f |
1.14 |
||
|
6 |
4 B |
712,241 |
36,815 |
674,926 |
m |
987,077 |
1.14 |
||
|
4 |
fi 4 |
869,466 |
31,271 |
828.195 |
1, 220,611 |
1 4? |
1.42 |
||
|
6 |
4.1 |
711,128 |
13,670 |
974,031 |
1.31 |
1.08 |
|||
|
« |
29 |
667,718 |
2,963 |
554.750 |
l,22(i,29( |
2 21 |
1.14 |
||
|
4.0 |
968,143 |
1,160 |
1,766.4U |
||||||
|
4 |
3 3 |
mi,R21 |
3,664 |
916,167 |
1,489,31^ |
1 62 |
2.4! |
||
|
5 |
« ? |
t92.S,394 |
13,166 |
910,214 |
2.024 |
1.466,42; |
1 W |
1.71 |
|
|
2.8 |
t987.968 |
3,153 |
l,66T.45b |
1.6i |
|||||
|
6 |
2S |
taoi.iei |
81,609 |
764,04H |
4,604 |
I.432,62J |
1 71 |
i.ei |
|
|
t5.'i0,26'l |
538,8.'i3 |
3,44f |
1 6(! |
||||||
|
1.8 |
t762,046 |
88,867 |
711, 70 |
3.618 |
1.276,003 |
1.70! •■'■' |
|||
'AS-
III
u
■S"5.
18,810 I
22,163 I
9,096 I
•17,233 !
$32.76 20.88 22,76
|
•21,446 |
|
|
•26,476 |
42.76 |
|
•29,461 |
30.26 |
|
•29,985 |
|
|
•13,046 |
22.26 |
|
•12.434 |
18.88 |
|
•16,928 |
17.63 |
|
•18.873 |
21.60 |
|
•29,934 |
28.50 |
|
•83,71 |
25.12 |
|
•87.731 |
25.76 |
|
•162,907 |
22.38 |
|
•167,483 |
19.88 |
|
18,00 |
|
|
•166,250 |
18.71 |
|
•175,715 |
20.92 |
|
18.88 |
|
|
•261,356 |
17.75 |
|
•327,912 |
18.40 |
|
•330,727 |
17.52 |
|
342.847 |
15.75 |
|
302,856 |
14.62 |
|
298,086 |
|
|
346,689 |
13.10 |
|
12.95 |
|
|
307,610 |
H.IO |
|
283,274 |
11.66 |
|
365,491 |
|
|
490,617 |
19.98 |
|
16,87 |
|
|
537,216 |
22.19 |
|
644,034 |
19.92 |
|
310.626 |
16.67 |
|
510,210 |
|
d bj Wtet Vlrglnta.
488 MINERAL RE80UBCE8 OF VIRGINIA.
The preceding table of production and value of iron ore and pig iron in Virginia is compiled from the publications of the IT. S. Geological Survey, from the U. S. Census Report and from the Reports of the American Iron and Steel Association. From this table it can be seen that the ratio of the pig iron production to the iron ore production has not been a constant one. This is due to the fact that there has been both exportation and im- portation of iron ore. Prior to 1880 there was little transportation of iron ores to or from the State or even within the State. For the most part each furnace smelted its own local ore. About 1880 there was considerable shipment of ore to West Virginia and Ohio furnaces, chiefly from the region about Clifton Forge. At this time also there was some shipment to Pennsyl- vania of Piedmont magnetite and of Blue Kidge linomite. In recent years there has been considerable importation of Lake Superior ores. There has been at various times some small importation of ores from adjoining states. At present there is gossan coming into the State from Tennessee and fossil ore being shipped out from Lee county. The large increase in production of iron ore about 1880 was nearly coincident with the first ex- tensive building of coke furnaces. The second rapid increase about 189(^ was at the time of the second period of coke furnace building.
Since 1900 the iron ore production of the State has added to the wealth of the State $1,500,000 annually, while the annual value of the pig iron pro- duced has been approximately $10,000,000. This State has had a constant and increasing production of iron ore for 180 years. The total value of the (»re that has been produced in this time is estimated by the writer to be $36,000,000.
Beferences.
Adams, W. H. The First Iron Blast Furnace in America. Trans-
actions American Institute of Mining Engineers, 1892, XX, 196.
The Site of the First Blast Furnace in America. Iron Age, April 13, 1893.
Historical Notes Bearing upon the Works of the First Mining Engineering of the Colony. Transactions of the Association of Engineers of Virginia.
Bishop, J. L. History of American Manufactures, Philadelphia?
1868, I, 702 pages.
IRON.
489
Boyd, C. R.
Brock, RA. Byrd, William.
Campbell, J. L. Campbell, M. R.
Catlett, Charles.
Chance, H. M.
Curry, Richard 0.
Barton, N. H.
Dewey, F. P.
Eckel, E. C.
Resources of Southwest Virginia. New York, 1881, 321 pages.
The Ores of Cripple Creek, Virginia. Transactions American Institute of Mining Engineers, 1884, XII,
27.
Manufacture of Iron in Virginia 1619-1776. The Vir- ginias, 1886, 133-134.
A Progress to the Mines. Writings of Col. William Byrd. Also quoted in part in the Virginias, 1880, I, 69-60.
Numerous articles. The Virginias, I- VI.
Geologic Atlas of the United States. Estillville Folio, No. 12. U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Pocahontas Folio, No. 26. U. S. Geological Survey, 1896.
Geologic Atlas of the United States. Tazewell Folio, No. 44. U. S. Geological Survey, 1898.
Geologic Atlas of the United States. Bristol Polio, No. 69. U. S. Geological Survey, 1899.
The Iron Ores of the Potsdam Formation in the Valley of Virginia. Engineering and Mining Journal, 1899, LXVIII, 167-168.
The Donald Iron Mine, Virginia. Engineering and Mining Journal, 1900, LXX, 485.
The Rich Patch Iron Tract, Virginia. Transactions American Institute of Mining Engineers, 1900. XXIX, 210-223.
The Copper and Iron Region of the Floyd — Carroll — Grayson Plateau of the Blue Ridge in Virginia. The Virginias, 1880, 1, 62-64, 69-71, 80-81, 95-96.
Geologic Atlas of the United States. Staunton Folio, No. 14. U. S. Geological Survey, 1894.
Geologic Atlas of the United States. Monterey Folio, No. 61. U. S. Geological Survey, 1899.
The Rich Hill Iron Ores. Transactions American Institute of Mining Engineers, 1882, X, 77-80.
The Oriskany and Clinton Iron Ores of Virginia. U. S. Geological Survey, Bulletin No. 285, 184-189,
490
MINERAL RE80UBCE8 OF VIRGINIA.
Fontaine, Wm. M.
Frazer, P., Jr.
Holden, E. J.
Hotchkiss, Jed. Hungerford, W. S.
Johnson, Guy B.
Johnson, J. E., Jr.
Lesley, J.. Peter. Lyman, B. S.
Lyman, Benjamin.
McCreath, A. S.
McCreath, A. S.
and d^nvilliers, E. V.
McDonald, M.
Moore, P. N.
Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154, 155.
Notes on the Geology and Mineral Sesources of tie Blue Ridge. The Virginias, 1883 and 1884, lY and V.
The Iron Ores of the Middle James River. Trana- actions American Institute of Mining Engineers,
1883, II, 201-216.
The Brown Ores of the New River — Cripple Creek Dis- trict. Virginia. U. S. Geological Survey, Bulletin No. 285, 190-193, 1905.
Numerous Articles. The Virginias, I- VI, 1880-1885.
Mining in Soft Ore Bodies at Low Moor. Trans- actions American Institute of Mining Engineers, 1889, XVII, 103.
Methods of Working and Surveying the Mines of the Longdale Iron Company, Virginia. Transactions American Institute of Mining Engineers, 1892, XX, 96-107.
Origin of the Oriskany Limonites. Engineering and Mining Journal, 1903, LXXVI, 231-232.
Iron Manufactures Guide, New York, 1859, 772 pages.
The Staleys Creek and Nicks Creek Iron Ore Region Near Marion, Smythe County, Va. Transactions American Philosophical Society, 1872, XV, 33- iS.
Geology of the Low Moor, Virginia, Iron Ores. Transactions American Institute of Mining Engi- neers, 1886, XIV, 801.
The Mineral Wealth of Virginia. Harrisburg, Pa.,
1884, 157 pages. .
Iron Ores of the Valley of Virginia. Transactions American Institute of Mining Engineers, 1884, XII, 17.
Resources of the Upper Cumberiand Valley, South- eastern Kentucky and Southwestern Virginia. Louisville, Ky., 1902, 152 pages.
The New River — Cripple Creek Mineral Region- Har- risburg, Pa., 1887, 171 pages.
Report of a Geological and Mineral Examination of a Portion of the James River Iron Belt. The Vi> ginias, 1880, I, 10-13.
Report on the Iron Ores in the Vicinity of Cumberland Gap. Kentucky Geological Survey, 1878, IV, 241- 264.
COPPER.
491
Kitze, H. B. C.
Pechin, E. C.
Prime, Fred., Jr.
Rogers, Wm. B. RnflEner, W. H.
Swank, J. M.
Notes on some Magnetites of Southwestern Virginia and the Contiguous Territory of North Carolina. Transactions American Institute of Mining Engi- neers, 1892, XX, 174-188.
Iron Ores of North Carolina, North Carolina Geologi- cal Survey, Bulletin No. I. 1893, 239 pages.
The Iron Ores at Buena Vista. Rockbridge County, Va, Engineering and Mining Journal, 1889. XLVIII, 92-93.
The Iron Ores of Virginia and their Development. Transactions American Institute of Mining Engi- neers, 1891, XIX, 1016-1035.
Virginia Oriskany Iron Ores. Engineering and Min- ing Journal, 1892, LIV, 150.
The Oriskany Ores at Rich Patch Mines, Virginia. Engineering and Mining Journal, 1896, LXI, 113, 134 ; 159-160.
The Magnetic Ores of Page Valley. The Virginias,
1883, IV, 38.
A Reprint of the GeologA* of the Virginias. New York,
1884, 832 pages.
Report on the Landed Property of the Buena Vistu Company, Philadelphia. Pa., 1889. 104 pages.
Iron in All Ages. Philadelphia, Pa.. 1894, 654 pages.
n. COFPEE. General Statement.
The existence of copper ores in Virginia has been known since the early settlements in the State, and while many attempts have been made to mine the ores, resulting in the opening of many mines in each of the copper dis- tricts, not until recent years have they been, with one or two exceptions, produced in paying quantities.
In his "A History of American Manvfcuiures from 160S to 1860!* Doctor J. Leander Bishop says on page 599 of Volume I: "Thirty hundred weight of copper ore with forty tons of Iron are mentioned by
Anderson as having been received, from Virginia in
]T30. In Mecklenburg county, on the Roanoke, not very distant, a mine of copper which promised considerable gold was operated about seventy years ago on the lands of Solomon Draper.'*
492 MINERAL RESOURCES OF VIBGINIA.
Distribution of the Ores.
The ores of copper have wide distribution over the State, although there are at present but few producing mines.
Geographical distribution, — The distribution of the principal copper deposits in Virginia is given on the accompanying map, figure 76. The known geographic areas of these ores in the State are:
I. The Piedmont Region.
(a) The Virgilina District, which includes Halifax county,
Virginia, and Person and Qranville counties. North Carolina.
(b) The deposits near Keysville in Charlotte county; those near
New Canton, Arvonia, and Dillwyn, in Buckingham county; and those on or near Southwest Mountain in Albemarle county.
II. The Blue Ridge Region.
Includes those deposits from near Front Royal southward, and embracing parts of Warren, Fauquier, Rappahannock, Madison, Page, and Qreene counties.
III. The Southwest Virginia Region.
Includes the "Gossan Lead'* of the Floyd-Carroll-Grayson coimties plateau.
IV. The Triassic Areas.
Includes the deposits near TiCesburg and Drakeville, in Loudoun and Culpeper counties.
Geological distribution, — The copper ores are confined, geologically, t^ the crystalline rocks, either the schists or the massive igneous rocks, of the Piedmont and Blue Ridge regions, and to the red shale — sandstone series of the Triassic areas. The ores in the Virgilina district and a part of those to the northeast, near Keysville. in Charlotte county, occur in quartz fissure veins, which intersect masses of altered volcanic rock (meta-andesite) of pre-Cambrian age. Those of the Blue Ridge region of northern Virginia are disseminated through and segregated in, basaltic flows of pre-Cambrian age, designated by Keith as Catoctin schist.
The "Gossan Lead" of the Floyd-Carroll-Gravson plateau, in southwest Virginia, is apparently a mineralized faulted zone in crystalline schists of doubtful age, probably pre-Cambrian in part. The rocks are in part altered sediments and in part igneous masses of basic and acid types, princi] the former.
|
^^^^~-H |
|
^,41. ''■^<~f'^i^^ |
|
.,«•*' ^ W^lP^^^:- |
|
■i ^ I'i^^^i^j^^'SC. |
|
i"^5Tv "n^^'^^^^^/UTn^^^-i^vvN - |
|
V^ /1^K2j^)^V '^^J'-^jJ^k^^^Ss& |
|
^^^mfJSlX' |
|
^^S|^a^^^^>^/^j^^^jjE^ 1 |M < |
|
'^^^K |
|
'''^1 '=^^^(^=^r^r' |
|
^'^^■^^^^ m:^S4-t^ '^ ^ |
|
''/"^^S; |
|
''* tfjlm!' |
|
-51 <^*W |
|
"* y^-lu^^^ |
|
• '''^n'^'%1." |
|
1 tWjJ |
|
! \l^i: |
494 MINERAL RESOURCES OF VIRGINIA.
The geologic conditions are so unlike in the different copper areas of the State, that the kinds of ore, their association and genesis, must be con- sidered separately by areas, as enumerated above.
THE VIKOILIHA DISTEICT.
Introductory statement. — The Virgilina copper district, which derives its name from the town of Virgilina, located on the Virginia-Caroliiu boundary, is situated 47 miles east of Danville, on the Atlantic and Dan- ville division of the Southern Eailway. The Norfolk and Western and Richmond and Danville roads lie not far to the north and west.
The mines thus far developed all lie upon a low ridge, a flat-topped elevation of from 100 to 260 feet abovie the neighboring stream-valleys, which is from 2 to 3 miles in width. Prospecting and mining are con- fined to an approximate north-south distance of 18 miles along the ridge, and to an average cross distance of from 2 to 3 miles. Although of no conspicuous height, the ridge forms a somewhat prominent feature in the landscape, and is traced northward in Virginia for a continuous distance of 10 miles. A similar area is found as far north as Keysville in Charlotte county. In North Carolina its southward extension is estimated by Hanna to be about 30 miles, reaching nearly to Durham.
General geology and petrography. — ^The country-rock is schist. Natural outcrops are relatively rare and seldom more than 2 or 3 feet high, form- ing sharp and narrow reefs which are persistent for short distances only. The microscope reveals the igneous origin of the rocks, though their true iirneous nature is usually not readily recognized in the field. Ordinarily they are schistose, soft, green and purple colored rocks, the schistosity having a strike of N. 10° to 20° E., and an eastward dip of from 70° to 80^ Diabase dikes of later geologic age cut the schists in several places.
The minerals composing the altered volcanic rock are: Plagioclase, light green amphibole, chlorite, epidote, zoisite, calcite, iron oxide (partly magne- tite) , quartz and apatite. Of these, only the feldspar, a part of the iron oxide (magnetite), and apatite are original. Both chlorite and epidote, intimately associated with more or less hornblende, are abundantly developed in most of the thin sections, sometimes one. sometimes the other, predomi- nating; but the two are at all times intimately associated.
Kinds and occurrence of the ores. — ^The workable ores comprise chal- cocite or glance (copper sulphide) and bomite (copper-iron sulphide) ia quartz, and to a slight degree impr^nations of the country-rock adjacoit \fi the YeiDB. At shallow depths cuprite (copper oxide) and malachite (gre^ coiyper carbonate) . oocnr as alterations of the original sulphides. A little natlTe copper oocon in places. Chalcopyrite and pyrite are almost entire-
■r^
• 4
•\ .•
'/
■"^- -^
\ .
"
I
Fig. 2. — SpW'iiren of ropper ore. Siuiie ti« Fijf. I. COPPKR ORK. VIRGILIXA niSTRKT. VIROISIA.
495
iy abaent, althoogh the latter is more abandant in the High Hill mine on the Yiiginia side than in any of the North Carolina mines belonging to this area. The ores are free from arsenic and antimony, bnt they carry at times very appreciable valnes in gold and silver, particnlarly the latter.
The ore occors in quarts reina. In gome places it is disseminated as finely divided particles throogh the more massive portions of the rock, with the woibble ore entirely confined to the quartz veins. The gangue is com- poaed chiefly of quartz with considerable calcite and epidote admixed lo- cally. Plate LXXI shows the occurrence of the ore. bornite and glance, in the qnartz gangue.
The veitu. — The district has many reins, which in general are more or less parallel, having a course of N. 5° to 10° E., and having overlapping ends. These cross the achistoeity of the enclosing rock in part, and in part are parallel to it
Uining developments show that copper occurs in almost all of the veins in greater or lees quantity. The veins are lenticular bodies of quartz, and forming in some cases very unifomi continuons outcroppinga at the surface. They show, in general, a lenticular structure, and like the gold veins of the southern Appalachians, they appear to be a succession of lenses connected by stringers of quartz. Figure 7? shows the bulbous or lenticular form of the quartz veins. The largest veins show outcrops nearly continuous for a half mile to a mile and more, and the undei^round workings show a con- tinnoQS body of quartz. Even the latest veins have a bulbous or leutic- nlar form, and the veins pinch and wid^i both horizontally and vertically. This is strongly marked in the smaller veins, and the lenses are frequently connected by a mere film or plate of quartz, which in certain horizontal cross-section may be wanting so that the vein appears to have given out *''K- 77.— Diagram illuBtrRtiug th«
. 131 jj.. I • structure of vein* fonned bv
A marked banded structure is some- the tearing *p«rt of achirt in-
timu observed in the veins, commonlT eluded betveen fauIt-Baaures or
,, „ ,. . .. ' adjacent to fiMures. (Aftw
seen near the walls, though it some- weed and Watson.)
MtXEHAL SGSODKCES OF VIBOINIA.
Fig. 78.— High Hill vein at shaft No. 4. North face of eO-foct level. Vein B to 9 f«et nide. Soft, flMile •chiat on the right. (Af- ter Weed uid Watson.)
a direction of aa much es N. 20'
times prcTBilfl for the entire width of the Tein. This banding is due to included plat«0 of the altered schist, which are often BO thin as to he mere films or dark etreakings in the vhite gangne. Figure 78, a section of the High Hill Tein at shaft No. 4, Halifax county, ahowi the banded stmcture. The schiBt-films ire often marked by ore. In places the banded structure is marked where the gangue consists largely of calcite. In some cases it appears as though a slight movement had torn apart the wall in a ragged way and quartz had filled tn between the sheets of rock.
The veins show a general uniform strike of N. 6° to 10° E., though there are a few exceptions in which cross veins aboir ' E.
Dnoription of the Xinet.
Historical. — The district has been more or less prospected for the last 60 or more years, as shown by the pits and shafts extending 8 miles north, and as far south, of the State line.
In the North Carolina portion of the belt, the Qillis mine was operated rs early as 1866, and a fine body of glance ore exposed. Considerable a^ tivity was manifested in the district in 1886-87 when the Blue Wing mine was openp<i and 500 or more tons of the ore extracted. The Yancey min^ now one of the mines of the Person Consolidated Company, was prospected ■t this time, but on account of unfavorable reports made by experts, it re- mained idle until 1897. The district was again the scene of active opera- tions in 1897, and some 226 carloads of the ore were taken out and shipped. Active prospecting and development work were again in progress from 189S to 1904. Just at this time, 1906, only one property is producing in the difl- trict, namely, the mines of the Person Consolidated Company, located an the southern end of the belt in North Carolina.
IXDIVIDOAL MINEB.
Figure 79 is a sketch map of the Virgilina copper district showing the location of the principal mines.
The High HUl mine. — Although idle at presoit, 1906, the High Hill mine is one of the largest and moat important mines in the VirgiliM
d^per diitricL The property compriaes 620 scree of land, located 9 miles north of Virgilina. It ext^ids from the banks of the Htco river aonthvard to the cross-roads leading from South Boston. It is owned bv the Virginia Copper Compsnv and it represents the most important development in the Virginia part of the field.
The property i5 crossed bv several well- defined and persistent veins which have been developed as follows; in 1904, the main or principal vein was prospected for a distance o( 9,702 feet, and the second parallel vein a dis- tance of 6,304 feet. The westenimost of the two, or the High Hill vein, is clearly traceable for 3 miles, extending from the Hyco river to a point one mile south of the company's hold- ings. A careful examination for the entire distance reveals very generally a quartz out- crop, rising from a few inches to 3 feet above the surface, and from 3 or 3 to 12 or 15 feet in width. In a few places it is broken down and can only be recc^nized by a scattered quartz drift. It is very persistent in direction and has been opened by an adit (timnel) and by 12 shafts, every one of which shows ore.
The only place where the adjacent schist? have been exposed is at the No, 7 shaft, where a pit 20 feet deep and about 20 feet west of the shaft shows schists impregnated with copper and bomite. Throughout most of the property the outcrop is from 125 to 166 feet above the river. The 7 most northerly ahaftd are well timbered and expose the vein at depths of from 55 to 140 feet. Both veins are found to be highly mineralized for their entire dis- tance. In March. 1904, the No. 4 shaft was 339 feet deep and the No. 3 shaft 367 feet deep, both vertical. (Plate LXXIV, figure 2.) The average amount of shaft sinking was 1,149 feet, with 2,306 feet of levels opened up but not sloped.
498 KINERAL BE80UR0E8 OF VISOIKIA.
The High Hill vein is almost eontinuouflly copper-bearing though of unequal value. The average width is 4 feet, and the ore-shoot developed by shafts Nos. 3 and 4 is about 1,000 feet long; that of No. 2 shaft is abont 200 feet long.
The shafts nearest the Hyco river are 107 feet deep and are connected by a level 180 feet^ and is continued 130 feet further south from the shaft No. 8 shaft is 72 feet deep and has a 9-foot drift at the bottom. A total of 167,000 pounds of ore have been shipped which averaged about 15 per cent, copper; the richest carload showed on sampling 27.83 per cent; the poorest 7.6 per cent. The gold and silver values are variable but samples from the stock piles of first class ore yielded 8.46 oz. of silver and 0.22 oz. of gold, per ton.
The equipment at the High Hill mine is extensive, including steam- hoists, boilers, air-compressor and drills ; and a conmiodious Tnill containing crushers, pmnp, packing belt, tronmiels, jigs, hydraulic classifiers, and Wil- fley tables. The company has produced up to March, 1904, 212,455 pounds of refined copper and 2,485 pounds of refined silver. The con- centrates carry $4.00 per ton in gold.
The Anaconda mine. — The Anaconda mine is located close by the main road about 1.5 miles north of Yirgilina. The vein is opened by a shaft 140 feet deep with drifts run north and south on the 100-foot level, 86 and 115 feet long respectively. About 7 carloads of ore have been shipped from this mine which varied from 3 per cent, of copper in the first carload to 12 per cent, in the last 5 carloads shipped. It is expected that the vein, which promises well, will be further developed as it has not received an extensive trial. The ore thus far extracted has been taken from one shoot.
The Dorothy mine, — This mine is located on the west side of the ridge 3.5 miles northwest of Virgilina and is developed by 2 shafts which are 60 and 100 feet deep, respectively, with levels run at the 25- and 100-foot level?. One carload of ore has been shipped and several are on the dump.
The Halifax Mining Company's mine, — The WWl mine located about halfway between the High Hill mine and the town of Virgilina is owned by the Halifax Mining Company. The vein is about 4 feet wide and is devel- oped by a shaft 150 feet deep with drifts extending north and south from it.
The Chappel mine. — This mine joins the High Hill property on the northeast. It is developed by two shafts 55 and 87 feet deep with about 150 feet of drifts.
Other openings. — Numerous smaller prospect openings have been dug on the outcrop of the veins north of Virgilina in Halifax county, Virginia. In nearly every one of these reasonably good indications are shown, but m
COPPER.
499
Bin 100 Tons
Itn.
8cr»eii hole*
Orcrslae
Slake ' Jrusher 13x20 1n.
nnd< rslze
CONCBNTRATING 8YSTBM
at the
OURGY UlU,
Otc raise
BnllB
Underalae
OrersiM
(
SetUing Taak
Overflow To
Sll ue
Waste
Two
wiirn
Tables
Imi>aci[ Screen
nn<
erslse
U
1
Class!
Orerslze
fler
Ovepflow
_J
Sail
Heada
Tills
Heada ^'^^^ '*^^
I
^ Hatoh Middlings Tl Us
Tli^ WUflejl Tables
Tl,lls
To
Waste
T( Wa«te
Fig. 80. — Concentrating system at the Durgy mill, Virgilina copper belt, son county, North Carolina. (After E. K. Judd.)
Per-
500 MINERAL RESOURCES OF VIRGINIA.
most of them developments have not extended far enough to warrant definite statements.
Figure 80 gives the scheme for concentrating the ore at the Diirgy mill in the North Carolina portion of the Virgilina district.
THE KEYSYILLE ABEA IK CHARLOTTE COTTNTY.
Several prospects for copper ore have been worked in the vicinity of Keysville in the northeast comer of Charlotte county. The nearest one 2.5 miles southwest of Keysville comprises a shaft and several open pits sunk in a belt of sericite-quartz schist. The foliation of the schist shows a northeast southwest strike, and a dip of about 80° southeast. The ore is green car- bonate, malachite, associated with quartz lenses and stringers, which con- form to the foliation of the inclosing schist. The openings had been aban- doned when visited in July, 1906, and very little ore was in evidence.
The second prospect, located about 6 miles southwest of Keysville and Imown as the McNeny mine, was working in July, 1906. The first opening, a shaft about 60 feet deep, was made 12 years ago, and is about a quarter of a mile east of the Weaver shaft which was working during July of the present year. Some work was done in 1905 and again resumed in March, 1906. The shaft is sunk on an incline of 30° to the southeast, following closely the dip of foliation of the rock, and in July had reached a depth of 100 feet.
The copper-bearing rock is identical, lithologically, with that of the Vir- gilina district, lying a short distance to the southwest, and is accordingly an altered volcanic rock, andesite. It is thinly schistose and otherwise much altered by epidotization. So far as developments have gone the quartz masses carrying the ore conform to the foliation of the inclosing altered volcanic rock. The quartz bodies are apparently not so large as those iu the Virgilina district, but the character of the ore, its occurrence and asso- ciations, are similar to those of the Virgilina district. Gray glance (chalco- cite) and bomite, with some green carbonate, malachite, make up the ore. Glance seems more abundant than bomite. Neither pyrite nor chalcoppte was observed. Lean ore occurring as impregnations in the altered volcanic rook is sometimes observed next to the quartz masses.
THE BXTCKINaHAM COUNTY DEPOSITS.
Copper ores have been prospected at three localities in the northeastern part of Buckingham county, namely, near New Canton, Arvonia, and D"^" M'vn. Neither of these localities has as yet proved productive, although the
COPPER. 501
prospects are reasonably encouraging, especially at Anaconda, 5.5 miles northwest of Dillwyn, and at the Lightfoot mine, 2 miles northwest of Arvonia.
New Canton mines, — Beginning at a point three-quarters of a mile south of New Canton, and extending for a distance of nearly a mile along a south- westerly course, a number of openings, principally shafts, have been sunk. The most extensive workings are on the Johnson place, formerly known as the Staples mine, where the main shaft has reached a depth of 265 feet, with a total length of 1,000 feet or more of drifts, run at diflPerent levels from the shaft.
The country-rock is mica schist, partly chlorite, and usually more or less gametiferous. The foliation has a general strike of north 20° east, and a dip that is very nearly vertical. At the McEenna shaft the ore is largely pjnrite, containing some intermingled chalcopyrite, which occurs principally as thin lenses interspersed within the schist as impregnations, while thread- like stringers of ore occasionally cut across the foliation of the rock. The mineralized zone varies from a fraction of an inch up to 2 feet.
At the Johnson shaft, 450 feet southwest from the McKenna shaft, pyrrhotite is associated with pyrite and chalcopyrite; and in places, glassy crystalline grains and larger pieces of quartz, often more or less rounded, are incorporated in the ore. Garnet is also occasionally found associated with the ore. Further, at the Johnson shaft, the ore is associated with a hard and fine-grained, dark greenish-gray,* massive rock, resembling an altered igneous type. The ore is reported to be both gold- and silver- bearing.
The United States Mineral Company's mine. — This company has recently done some development work with promising results at Anaconda, formerly known as Eldridge's Mill, situated 5.5 miles northwest of Dillwyn, and 4 miles west of Johnson, stations on the Buckingham branch of the Chesapeake and Ohio Railway. Pay rock has been taken from a 60-foot shaft sunk at this local it v.
ft-
The copper-bearing rock is a fine-grained, dark green, eruptive rock, which has been greatly altered by pressure, and the development of chlorite end epidote, being not unlike that of the Virgilina district. Crystals of red garnet are not uncommon in the rock. The ore is cupriferous pyrite with some chalcopyrite occurring principally in quartz masses, which usually conform with, but at times cut across the foliation of the inclosing eruptive rock. Some secondary green carbonate, malachite, derived from the sulphides, occurs.
502 MINERAL RES0UB0E8 OF VIBOINIA.
The Lfightfoot mine. — The Lightfoot mine is located about 2 mile? northwest of Arvonia, directly on the east side of Slate creek and at an elevation of about 20 feet above the stream level. The ore-bearing rock is a dark green thinly foliated chloritic schist, which bears striking evidence of its derivation from an original eruptive rock. It is qnite similar to that described above from the United States Mineral Compan/s mine 5.5 miles northwest of Dillwyn. The rock is considerably epidotized in places, is crushed and fractured, and carries quartz stringers and eyes. Some small masses of calcite were observed. Strike of the schistosiiy is northeast- southwest with a steep northwest dip.
The mine is developed by an 85-foot shaft from which several short drifts have been run. Preparations wre now in progress for sinking th?
shaft several himdred feet deeper, ext^ttding the drifts, and opening new ones on lower levels.
Much ore is in evidence bothbn the dump and in the shaft. It com- prises cupriferous p3rri[te chiefly, with aome chalcopyrite. Good values in gold are indicated by a large number bf assays made of the ore.
THE ALBEXASLE COTTHTY DEPOSITS.
The Stony Point copper vein. — Northeast of Charlottesville on the west- em foot-slopes of Southwest Mountain, in Albemarle county, is a vein cut- ting through micaceous schists which was worked for about a year as an iron deposit. The upper part of the vein, the gossan, is composed of limonite which was shipped to the Pittsburg furnaces.
The mines are located in the foot-hill country at the west base of South- west Mountain, on a small branch of the North Fork of Hivanna river. They are located about 2 miles to the east of Stony Point and a quarter of a mile from the main Charlottesville pike. The mines are 2.5 miles from the railroad and 12 miles from Charlottesville. This property was bought by Major Mason in 1878 who worked it in 1885. Numerous openings have been made including shaft, drifts and open cuts, or pits. The shaft which is inclined is reported to have reached a depth of 130 feet. The principal mining has been the gossan for iron ore, of which 2,500 carloads are re- ported to have been shipped, some of which is reported to have averaged very high in iron. Mining was discontinued here about 15 years ago.
The country-rock is a bleached and altered, thinly foliated, sericitic schist. The hanging-wall rocks appear to be more altered than those of the foot-wall. The vein is from 5 to 6 feet wide, which width is nearlv uniform throughout its extent. Tn the northern part of the property the
^^'"/^
<sr<
^^Tri^.^^X
: I
I
5'
COPPEB. 503
vein strikes north 36° east (magnetic) and dips 55° sonth. To the south end of the property the vein strikes south 80° east. It consists of a solid mass of gossan which appears when broken more or less cellular, with siliceous portions and occasionally with quartz streaks. The dump is com- posed of siliceous iron ore with occasional blocks of white quartz contain- ing bands and thin layers of chalcopyrite. No pyrite was observed either in the quartz or in the altered schists about the vein.
The iron of the gossan has probably resulted from the alteration of chalcopyrite, which alteration extends to a depth of more than 100 feet. It seems not improbable that a thickness of secondary copper glance will be encountered between the gossan and the unaltered primary ore. Samples of the chalcopjrrite were assayed with reported yields of $5.00 per ton in gold and 15 per cent, in copper.
AMHES8T COTTirrY DEPOSITS.
Amherst county contains green-stained rocks at the Folley, and numer- ous old openings attest the endeavor of earlier explorers to find workable deposits. Professor Rogers again remarks, "that no distinct vein or bed cf copper ore is indicated, but rather an impregnation of the talcose rock of the neighbourhood, more or less strongly with the compounds of the metal. In some of these places the manufacture of copper has been attempted, but without the success that would justify a prosecution of the enterprise.'*
THE BLUE EIDGE COPPER DEPOSITS.
Location and history. — As indicated on map, plate LXXII, the Blue Ridge copper region is located in the northern part of the State, and includes those deposits from near Front Royal southward and embracing parts of Warren, Fauquier, Rappahannock, Madison, Page, and Greene counties. Copper ores have been known to exist in the Blue Ridge mountains since the earliest settlements. The native copper of the region probably furnished the Indians with the metal from which their ornaments and axes were made.
A few attempts were made to extract the metal in colonial times but not until 1854-56 were large simis of money expended in this r^on in attempts to work the ores. Operations were suspended at the beginning of the Civil War and the properties remained practically idle until within the past 10 or 12 years, when attempts were again made to work the owf at many places over the region. During the past 2 years, 6 companies and a few private individuals have been engaged in development work.
UINEBAL BE800BCE8 OF TIROtNIA.
Oeolosy.
In the copper region, the Blue Ridge is made up of a central core of igneous rocka, nuwtly a dense and black basaltic type flanked by Bjenite ud other igneous types, frequmtly altered to Bchistoee fonns. Besting against these rocks at the base of the mountains and forming the Valley region to the west is the folded sedimentary series, which Keith designates ta Cambro-SUurian in age. So far as known the Bedimentary rocks are not «>pper-bearing but the ores of the region are confined to the igneous rocks of the basalt type.
id quart*. Stony Mao P«i.
The basaltic rock is <ipnse, hcavv and diirk-t'olored. and parts of it arf altered and sometimes schistose. According to Keith the schistose character of flic rock is emphasized in the Harper's Ferry region and the rock is designated by him Catoctin schist. Further south in the copper r^on the schistose character of the rock is much less well-deiined. though in plares it is sheelcd \ertirally from close jointing along shear z.ones.
Keith recof^ni^es two varieties of the basalt near Harpcr'a Ferry, ft li)*^f diabase sheet and an upper basalt sheet, both altered and the upper one large- ly epidotizcd. An amygdaloidal phase of the upper epidotized sheet is
505
shown in places. A coarse-grained, usually massiTc, and dark grayish green syeoite has been traced at irregular inta-vals along the west side of the mountains from Dickey's Hill south of Front Royal in Warren county, southward to High Top in Greene county.
The upper sheet of basaltic rock is generally much altered by secular decay and in part forms a greenish chlorite and epidote schist. According to Eeith the igneous rocks including the basalt or Catoctin Bchist are Algonkian (pre-Cambrian).
Character and Hode of Ooomrenoe of the Ores.
The oree consist chiefly of cuprite and native copper with small amounts of the sulphides, bomite and chalcopyrite. The native copper often occurs as nucleal masses surrounded by cuprite. Bomite is in escess of chal- copyrite. The ore occurs along crevices and joint-planes, in small, irregular cbaped lenses of quartz, and as disseminated grains through the more epidotized portions of the basalt. It occurs mostly where the rocks are fractured and epidotized as shown in figure 81. When ore-bearing the rocks are yellowish-green in color, due largely to the formation of epidote and in part of chlorite. Figure 82 shows a partial basalt shell filled with epidote, and the epidote rimmed by bomite next to the basalt. Figures 83 and 84 show the occurrence of native copper in quartz and in asbestiform serpentine.
The ores do not extend more than 50 feet below the surface at many of the localities and at some it is less. From their occurrence in shear zones in the rock ; from the confiuGment of the ore mainly to the secondary i epidote and quartz vdnlets ; and from the character of i the ore itself, it is believed that the ores have been formed by a concentration of material leached out of locally copper-rich portlnns of the igneous rocks. Tho shear zones have afforded a place for the gathering of these solutions and the deposition of material. The ores seldom occur in actually continuous masses, but can sometimes be traced for miles by the copper-bearing debris.
Weed and Wat-
MINEBAL RE80US0B8 07 VIBOINIA.
Fig. 83. — Quartz with a little calcite and native copper. Black areas copper. Lined area schistose baaalt. Fletcher, Greene county. (AfUr Weed and Watson.)
Fig. 84. — Asbestiform serpentine with native copper. Black ami cop-
er. 7 miles southeast of Luraj, ige county. (After Weed and
SESCRIPTIOIf OF THE imES. Warren Comity.
The copper ores found in (he region east and south of Front Royal have attracted attention for many years. In recent years several mining companies have done more or leas exploration ivork and their shafts and tunnels have afforded a favorable opportunity for the study of geologic conditions. The district embraces the main Blue Bidge summit extend- ing from Linden southward.
East of Front Royal and south of Linden, on a tract of land reported to have been originally granted to Lord Fairfax and subsequently trans- ferred to Chief Justice Marshall, good indications of copper appear in the outcrops and as loose masses over the surface. In the early part of the last century a number of shallow pits were Btmk at several places, bat no shipments were made until 1861, when 35 tons were collected from the surface and from a 50-foot shaft and shipped abroad. This ehipment of ore is reported to have averaged over 10 per cent, in copper.
COPPER. 507
The Sealock property. — ^This property has been yery extensiyely developed by shafts^ drifts, and small openings. It is located about 3 miles in a direct line from Linden. The principal shaft on this property, known as the Phillips' shaft, was sunk to a depth of 80 feet, and a considerable quantity of good ore is reported to have been extracted. A recent tunnel 200 feet long has been driven into the hillside on another part of the property with the object of cutting the so-called copper "vein** on which the Solomon shaft was driven. The ore thus far taken out consists chiefly of native copper and cuprite with malachite, the green carbonate, and a small amount of azurite, the blue carbonate. Some chalcopyrite also occurs. An examination of the dumps at many of the openings on this property by the writer in 1905 showed many beautiful specimens of copper ore.
Dickey's Hill mines. — Dickey's Hill forms a high outlier of the Blue Eidge proper, lying to the west of the main divide. The copper ore is not uniformly distributed over this ridge but occurs in a few localities where more or less work has been done to determine the size and character of the ore-bodies. The Mill's property (Cove Farm) represents a recent working located about 8 miles from Front Royal.
In 1906 a copper-bearing outcrop of epidote rock exposed in a ledge 60 feet long and 20 feet wide and located about 200 feet below the summit of the mountain had been opened. The opening was a cut about 7 feet wide and 36 feet long extending back into the hillside. The copper ores comprised native copper, malachite, and azurite, chrysocolla, and lower down a litte bomite. At the time of my visit in 1906 the property had not been suflBciently developed to warrant a definite statement.
RudacUl property. — In August, 1905, this property was being worked by the Virginia and Pittsburg Copper Company. The company has made openings at two points on the south end of Dickey^s Hill near the summit, where some shallow openings have been put down and a couple of cabins erected. At that time the workings were located in the cove southeast of the end of the ridge at a point halfway up the slope, comprising a cut about 75 feet long, and about 100 yards distant therefrom, and a shaft sunk to a depth of about 50 feet. The ore comprised native copper, considerable carbonate, malachite, and copper oxide.
The Bentonville-Overall District.
This district is located 12 to 15 miles south of Front Roval and some of the earliest prospecting for copper in the Blue Ridge region waa to the
608 MINERAL RESOURCES OF VIRGINIA.
south of Bentonville, a station on the Norfolk and Western Railway. Within the past 12 or 15 years considerable work has been done on \ nnmber of properties in this vicinity.
In 1905, operations had been suspended except some prospecting work on the Empire ''vein'':; tocated on the summit of the ridge known as Mathews Arm, near the Page- Wuriren county line. Several pits have been dug on the Empire ^Vein" showipg chiefly malachite with some bomite and cuprite. ' » '
In 1903-04, a s^/aft and several openings were put down on the Martin property, located about ^ miles, northwest of the Empire ^*vein" and about '? miles southeast of Bentonville, about halfway down the ridge slope. The shaft is reported to have peached a depth of 90 feet. An inspection of the material on the dump showed the ore to consist essentially of mala- chite and azurite with some bomite.
A second shaft is located lower down on the ridge toward the south- west on the land of F. C. Hartley. This is of long standing and waa worked more than 30 years ago. Several other smaller openings, some of which are recent others of long standing, are made in the vicinity.
Bappahannock Connty.
The Anihler property, — Several openings have been made on this piopertv comprisincr an open cut and tunnel, a shaft and several smaller openintrs. The shaft is sunk on the north end of the property some distance below the ridge crest and is reported to be 40 feet deep. An examina- tion of the dTimps from the shaft showed bomite and native copper with malaehite. Similar conditions were noted at the open cut and tunnel. A ('0111)10 of inik^ from the Sealoek ])ro{)erty is a fine exposure of coppr ore in a rocky ledge known as Cottam rock on the Ambler place.
The Mavassas Gap Copper mine. — The openings of this company arp located on tli-.^ slope near a $mall stream, which forms a part of the head- waters of the "Rappahannock river, distant from the latter about 600 feet r.Tul (5.5 miles south from Front Royal. Openings have been made on the property at the different places, 4 of which are on the east slope of a steeply sloj^ing ridge, the other on top of the ridge, Raven Den Monntain- These comprise shafts, tunnels, and some open work. The greatest depth 1 cached in the shafts is reported to be nO feet and the most extensive tinmol ap]>roximatcs 200 feet in length. The same kind and character of orr was observed by the writer on the dumps at these openings as froi^
' .>
UINEIUI. ItEHOt'RI'KH Of VIKIJIXIA.
I.ATE I.XXIII.
I''i>.'. I.— View ulimvin): slinft limiw. ore <hiTii|>. and basalt ctilfs, at the llliK> Itiilt.'!' ('«|.pei' r<ini|>iiiL.v'H mini'. Madixon county. ( Unpublisliril report liy Weed and Wstson. )
Cni'I'Ki: MIXICS IN- THK XOIiTllKRN KLIP: UirKJK RKOIUN. VIRO.IXIA
COPPER. 509
the mines described above. In 1906, the compan/s equipment comprised 0 saw-mill^ blacksmith shop, and a varied assori^ment of mining tools.
Page Connty.
The copper properties southeast of Stanley, in Page county, lie on the tiank of the Blue Ridge to the east and west of the summit of the ridge, which forms the dividing line between Page and Madison counties. The district has long been known as showing some of the most promising out- crops of copper ores in the Blue Ridge region, and the development near Ida post-office, on the headwaters of HawFs Bill creek and in Dark Hollow are more extensive than any other part of the Blue Ridge.
The Virginia Consolidated Copper Company's mine. — One of the most extensive developments in the Blue Ridge district of Virginia is that of the Virginia Consolidated Copper Company, with head offices at McKees- port, Pennsylvania. The property, comprising 160 acres, is located on one of the foothills at the west base of the Blue Ridge, about one mile west of Ida, and about 5 miles southeast of Luray. The company has made extensive developments but operations were temporarily suspended in January, 1905. A manager's house, a laboratory, shaft-house and other out- buildings have been erected, and the shaft-house equipped with 2 J2-H. P. Fairbank-Morse gasoline engines; the one for hoisting, the other for ventilation and working two compressed air drills.
In the summer of 1905 an incline shaft had been sunk 308 feet deep, with drifts run on the 80-, 120-, and 280.foot levels. The drift at the 80- foot level extends for 70 feet to the east. The 120-foot level has been driven from 180 feet west in solid rock. The 280-foot level shows 260 feet of work. (The shaft house at this mine is shown in plate LXXIII, figure 2.)
The ore comprises the oxidized forms, malachite and azurite, and some red oxide and native copper. No sulphide ores were seen by the writer.
Madison Connty.
The Blue Ridge Copper Company's mine. — ^The property of the Blue Ridge Mining Company of Chicago comprises about 180 acres of land in Dark Hollow, at the head of Robinson river and about one mile to the south- east of Milam^s Gap (also known as Fisher's Gap), very near the crest of the Blue Bidge. This is the best developed property in Madison county. The exposures of copper ore found in this vicinity are reported to have been worked before the Civil War, but they have been abandoned for many years.
510 MINERAL RESOURCES OF VIROINIA.
The operations of the present company were begun some 5 years ago. The workings comprise what is known as the old shaft or shaft No. I, located at an elevation of about 250 feet above the confluence of the two main head- water branches of the Bobinson river. This shaft and the small opening a short distance to the southwest were made some years ago. Two drifts were run from the shaft, one in a north 12** west direction for 20 feet, and the other in the opposite direction for 9 feet. A few tons of ore are reported to have been shipped from this shaft (Plate LXXIII, figoie 1.)
The new shafts No. 2, is an incline 42 feet in length and located ahout too feet below the mouth of the old shaft From the bottom of this in* cline a drift has been run for 40 feet in a northeasterly direction for the purpose of intersecting the zone of copper-bearing rock cm wliidi the Old shaft was started. In 1904, a third shaft was bq^on, located noifhvest of and higher up the hill than the old shaft, No. 1.
The ores found in these openings comprise native copper, blue and green carbonates, a little cuprite and some chalcopyrite. The wozldiigs of this company are located quite close to the contact of basalt and ajenite, shaft No. 2 being not more than a stone's throw away. The ore is confined to the basalt and as yet has not been observed in the syenite.
Stony Man openings, — To the northeast of Milam's Gap and near Stony Man peak some prospecting for copper ores was done many years ago. A shaft filled with water at the time of my visit is reported to have reached a depth of 60 feet, with the usual quantity and mineralogical fonns of ore shown as described above.
Greene County.
The Blue Ridge region of Greene county contains several copper pros- pects, only two of which have been opened by mining operations. These are the Sims mine, 5 miles north of Stanardsville, and the mines of the Hightop Copper Mining Company, 7 miles east of Elkton.
The Sims mine. — The Sims mine is located 5 miles north of Stanaria- ville, the county-seat of Greene county, and on the eastern slope of the Blue Bidge. A number of shallow openings have been made in places and a shaft 30 feet deep has been sunk. A short cross-cut driven 25 feet north is made at a depth of 30 feet. The ore is native copper, cuprite and chalcopyrite in small amounts.
The nightop Copper Mining Company's mine. — ^The mine of the High- top Copper Company, the most extensively developed one in Greene county, is located 7 miles east of Elkton on the summit and southern side of ths
MINEItAl, KESoritCES Of Vlltr.
LATE LXXIV.
Fij;. 2.— Vieu of shaft N'o. 3. Hit-h Hill copper mine of the VirRinia Cup- jier Conipiiny, Hnlifnx county. ( Unpublisbed report hy Weed iind Watson. I
BLUE RIDGK A\D SHAtT OF COPPJ^l MINE, VIROiXIA.
\
OOPPEB. 511
southeast spur of Hightop Mountain, at an elevation of 3,000 feet above sea-level. In the fall of 1905, the workings consisted of extensive strip- ping of the ledges exposed on the mountain side, of a cross-cut tunnel about 150 feet in length below a shaft reported to be 80 feet deep, sunk from the bottom of an open cut driven on thehiUside.
The ore observed at the openings of this company consisted of native copper, cuprite, some malachite,'and iii^|)lace8 a little botnite and chalco- pyrite. ^'.:L'v
A tunnel, entering the hills^e^.alr a distance of 400 feet below the summit of the ridge, has been driVeji for a*, distance of 111 feet, along a S. 50** E. course. The open cut and -^haft' mentioned above are 200 feet above the tunnel and the same distance 'below the top of the ridge. The mining camp of this company is probably the most extensive one in the district.
THS SOXTTHWEST VIBOIinA &EOI0N.
The ''Gossan Lead" of Floyd, Carroll, and Grayson Counties.
Oenerdl statement. — ^Probably the most noted copper region of Virginia is in the southwestern portion of the State, in a belt of crystalline rocks passing through Floyd, Carroll, and Grayson counties. The region is a part of the eroded Blue Ridge upland, marked by well roimded summits and deeply trenched streams, and is referred to as the Ployd-Carroll- Grayson plateau. (Map, figure 29, page 192.)
The region was actively prospected in the early fifties and the rich secondary copper ores found beneath the gossan were boxed and shipped to Baltimore. During 1854-6 there were 8 producing mines on the "Gossan Lead." The aggregate amount of ore shipped for the 6 months, from January 1866 to July 1855, was 1,545,363 pounds. The ore averaged about 25 per cent, copper, and at that time the metal was worth 26 cents per pound.
*
Oeneral geology. — The "Gossan Lead" lies in the ciysljalline schists and its strike conforms very closely to that of the enclosing rocks. A careful examination shows the vein to be traceable for a distance of 18 miles. From one end to the other there are old pits whose dump heaps show the typical gossan ore (figure 86), and as several of the old mine- workings could be continuously followed underground for miles running at a depth of from 20 to 60 feet below the surface, there seems little doubt that it is one of the greatest veins in the Appalachians.
The immediate wall rock of the ^^ead" is sericite schist. On the
513 MINEHAL RESODBOEB OF VIBOINIA.
Eoutheast or hanging-wall side of the vein the rocks are ordinary mica- Echista cut by altered diorite maseee. The rocks on the foot-wall side appear to be eomewliat different and are similar to the Ocoee rocks of the southern Appalachians. A belt of much altered hornblende ^mite ezteids upward and aci'oss the foot-wall series and is found near the "Goessn Lead" in the vicinity of Betty Baker. These facts and the atmcturc oi the vein itself prove faulting and, as the dip of the vein is from 45' to 60° the faulting is apparently of the overthruat type, vhich type predomi- nates in this part of the Appalachian region.
General character of the vein. — The vein consists esaentially of pyrrhotite with disseminated particles and stringers of chalcopjrite. It
Fig. 86. — Profile of "Ooasan Lead" from Betty Baker mine to Sirkbride mine. Bhowing goeMn (Hmonite) reMires. CarroU count;. {Aft«r Werd and Watson, unpublished report.)
is not in every place a solid mnse of pyrrhotite from wall to wall, but rather a series of layers, partly of pure pyrrhotite admised with more or less micaceous material, an altered form of the country-rock. The pri- mary ore is exposed at the openings of the Pulaski Mining Company at rhestnut Yard (fireat Outburst) at the southwest end of the "lead." (Plate XXX.) Projecting masses or intercalations of the schiate occur in the vein and. in places, where the fresh materia! is observable, a eonsiii- erable proportion of the vein consists of coarse biotite schist, impregnated with chalcopyrite and interleaved masses of pyrrhotite. Figure 86 shoTS the inlcrlcavinfT of pyrrohotite with talc at the Pulaski Mining Company's openings on riicatmit creek at the "Great Outburst," At the !ani« openings considerable hornblende is associated with the pyrrhotite in places as shown in figure 87. Quartz lenses occur on the hanging-wall of tbe
Fig. 88.
! pyTi
e talc. Chestnut Yard, Carroll county. Two-thirda tiatural (After Weed and Watson.)
The vein varies in width from 22 feet to perhaps 100 feet. A diamond drill hole wa» put down to a depth of 634 feet on the vein at the Bettj' Baker mine, proving the deposit to a depth of 734 feet below the outcrop. Other bor- ings , proved the width of the vein at Betty Baker to be 35 feet. The strike of the vein varies in accordance with that of the countrj'-rock ; at Betty Baker it is N. 35° E., and it shows various deviations from this when traced southward, reaching as much as N. 60' E. in places. It has not only Buffered from strike faulting, but shows sharp folding or change of strike southwest of thr Cranberry mine; and at the Betty Baker mine a horizontal displacement of 62 feet was measured close to the point where the wagon road crosses the ledge. The dip varies somewhat but averages about 45°. Marked discordance in the dip of the vein and that of the enclosing schists is observed in places.
In places, the vein-tilling comprises rock fragments of varying character cemented by the sulphides, principally pyrrhotite. Those fragments are often well rounded, sometimes subangiilar and include rock types not seen on the surface either at the vein or nearby.
Fig. 87. — Pyrrhotite with columnar horn- blende and ehalcopyrite. White is pyrrho- tite. Blacic is chalcopyrite. Pnralld lines are hornblende. Chei^tnut Yard, Carroll county. (After Weed and Watson.)
514 MINERAL RESOURCES OF VIROINIA.
Description of Mines.
The mines which were most extensively worked on this "lead'^ are: the Betty Baker, Cranberry, Kirkbride, Vaughn, Copperas Hill, and Chest- nut Ridge at the "Great Ontbnrst/' The location of these mines and the general trend of the "Gossan Lead" are shown on the accompanying map, figure 88. In addition to these^ numerous other smaller mines were opened in different places on the ^^ead," the principal ones of which were the Ann Phipps, Wolf Pit, and Wild Cat mines.
Carroll County.
Vaughn mine. — As indicated on the map, figure 88, the Vaughn mine is southwest of the Kirkbride, and has not been worked for many years. The shafts are numerous and they occur at such frequent intervals that there can be but little doubt of the continuity of the vein. As determined by the old shafts, the direction of the vein was about 66** east with a dip of 45°. The workings of the Vaughn mine and those on the adjacent properties made a continuous drift of 4 miles long. The ore from this mine was pounded up and put in boxes, and hauled to Max Meadows, where it was shipped to Baltimore. Mr. H. E. Vaughn reports that the ore was 75 feet wide in some places.
Cranberry mine. — The location of this mine is given on the accom- panying map, figure 88. The mine was closed down in 1859 after working for a period of about 7 years. A copper smelter was once operated at this locality and there was at that time a considerable settle- ment. The old workings for black copper consisted of long tunnels, with drifts along the vein, and frequent air-shafts along the surface, some of which were used for hoisting. The strike of the vein is north 55° (Nist. A shaft 104 feet deep, located in the creek bed, was worked for yellow copper ore. This mine was reopened again about 12 years ago by Edgar C. Moxham, Mining Engineer of New York City. In 1902 some diamond drill holes were put down by the Virginia Iron, Coal and Coke Company.
Wild Cat mine. — Crossing Cranberry creek to the southwest from the Cranberry mine is the Wild Cat mine, which was developed by a series of sliafts. These are still open down to the water level and show the strike of the vein to be north 65° east, and a dip of 45°.
The B villi Baler mine. — This mine is located about 3 miles southeast of Sylvatus and a short distance west of Big Reed Island creek. It has been
616 MINERAL RESOURCES OF VIRGINIA.
extensively operated, as indicated by the numerous cuts, shafts, and drifts, extending over a considerable northeast-southwest distance. Many of the older workings are in poor condition and little conld be seen from an examination of the walls. At the time of my visit in 1905 the shafts were filled with water and could not be entered. The narroweat place encountered on the vein was reported at No. 7 shaft, about one mile west of the otTice of the Betty Baker mine. At this point the vein was squeezed to 5 feet. At the east end of the Betty Baker property the snrface shows a width of about 300 feet of liinonite.
Before closing down the Betty Baker mine in 1900, 1,800 tons of the **mundic" (pyrrhotite) were shipped to the Southern Chemical Company at Winston-Salem, North Carolina, where it was used in acid-making. The ore contained 33 per cent, of sulphur, and after roasting it carried 68 per cent, of iron. Shipments to the Winston-Salem works were stopped when the plant was absorbed in the consolidation of the Southern Fertilizer Manufactures. Plate LXXV shows views of shaft and open cut at this mine.
The Gardner and Ooad mines. — These are separate mines, located close together in the northeastern part of Carroll county, about 10 miles from Betty Baker and not far from the Floyd county line. The openings are made in a dike of alten'd (schistose) hornblende rock, which cuts across the normal schists of the region. Occasional specks or nuggets of native copper have been found along the weathered outcrop and the dike has for this reason been referred to as a native copper vein. The strike of the count rv-r(Kk (seliists) near tlie mines varies from north 50** to 65** east, and (lips al)out G()° south. The mines have been opened by shafts and tunnels of moderate depth and length. The ore is chalcopyrite in more or loss rounded nodules ranging in size up to that of a hickory-nuL Post- mi n(Tal movement has squeezed these out into pyrite mirrors and streaks.
The "Great Outburst/' — The openings on this property are located near the Carroll-Oruyson county line, near Chestnut Yard, on the Cripple Creek extension of the Norfolk and Western Railwav, between Chestnut creek and New river. The gossan of the vein has been extensively mined from numerous shallow workings for iron. The pyrrhotite vein is very wide here. Tt is not a continuous mass of pyrrhotite from wall to wall, but the ore is interleaved with micaceous and talcose schist Plate XXX is a view of the vein as opened in 1905. The pyrrhotite contains stringers and small masses of chalcopyrite through it, usually not in large enough quantity to make it a workable copper proposition alone. The Pulaski Mining Company has been and is mining the pyrrhotite for add-making* with occasional shipments of the secondary black copper concentrated below the gossan.
UIXKKAL HKSorncES OF VIIKJISIA.
PLATE LXXV.
Fig- 2. — Open cut at Better Baker mine. Carroll ooiinty. ( Unpubliitbed re- port b; Weed and Watson.)
II
COPPER. 617
Orayson County.
As indicated on the map, figure 88, the "Gossan Lead" extends from Carroll into Grayson county, and, in the vicinity of Old Town, other probable ones are shown, but, so far as I am aw.are, the mining of copper along these belts has been largely, if not entirely, limited to Carroll county.
In the extreme western and southwestern portions of Grayson county, strong indications of copper exist in places. Less than a mile south of Troutdale, on the Greer place, the qua.i;t55-feldspar porphyry on Fox creek contains large granular masses and small grains of chalcopyrite. In the Siouthwestern corner of the county, near the North Carolina line, some prospecting for copper has recently been done on the Douglas Land Com- pany's property. Good specimens of the sulphides, bornite and chalco- pyrite, and the green carbonate, malachite, were obtained. The openings are made in a green schist not far removed from the porphyry contact.
Floyd County.
The Toncray mine, — The Toncray mine is located about 8 miles south southeast of Floyd court-house. It was last operated by the New York and Virginia Copper Company. For several years past this company was actively engaged in prospecting the property and large sums of money were expended in buildings and machinery, and the employment of a large force of men. The property has been developed by several tunnels and shafts. Work had just been suspended at the time of my visit in 1905. The vein is, like that described above in Carroll county, pyrrhotite. It was opened in search of the black oxide of copper, a large amount of which was reported found. Intermingled with the unaltered pyrrhotite is con- siderable chalcopyrite, which seems to be present here in amount larger than at other mines in Carroll county. It is reliably reported that in the upper tunnel a band of the yellow copper sulphide, chalcopyrite, was found which measured 6 to 8 inches wide. The rock inclosing the vein is the usual gray-colored mica schist.
Franklin County.
The Howell mine, — This mine, so-called^ is near the Rocky Mount- Tloyd court-house road, and is located about 1.5 miles from -Huffs store, in the extreme western edge of Franklin county. Very little work has l>een done. The ore is pyrrhotite, carr}'ing a small amount of intermingled chalcopyrite. The "vein'^ is found in tlie altered micaceous schists. Other deposits similar to this one are reported a short distance to the northeast and southwest of the Howell mine.
518 MINERAL RESOUBOES OF VIBGIKIA.
THE COPPE& O&ES OF THE &ED BEDS OF THE THIASSIC.
Several of the Virginia counties covered by the red sandstones and shales of the Triassic formation contain deposits of copper ores of too low grade to permit of profitable working. Numerous attempts have been made to mine these ores at many different points, but as yet without success. During the early part of the last century attempts were made to mine the ore over parts of Loudoun, Culpeper, and Orange counties.
Londonn County.
Five miles east of Leesburg and near Sugar Run in Loudoun county, the Triassic series contains greenish or bluish calcareous sandstones and shales intercalated in the lead rocks. The light-colored beds contain fihns or thin coatings of malachite on joint surfaces, and sometimes carry specks of the phosphate of copper and of copper glance. The area of mineraliza- tion is, according to Keith, extensive, and considerable work has been done; but the ore is too generally diffused to be profitably worked.
Culpeper County.
Near Stevensburg, 10 miles east of Culpeper, copper-bearing shales were worked. The conditions here are more or less closely similar to those described in Loudoun county. Rich specimens of copper ore are reported to have been frequently obtained during the early history of this region.
Professor Rogers' observations on this region seem to be applicable at the present time. He says: "Unhappily these indications have kept alive the hope of discovering in these shales veins of a workable copper ore and has led to repeated enterprises in mining, from which no really profitable result appears ever to have been derived. Most of the openings, either ancient or modem, have disclosed nothing more than a calcareous shale slightly filmed with the green carbonate, and making in some cases a superficial show of richness where analysis discovers only an insignificant amount of the enticing mineral."
Orange County.
Orange county contains areas of copper-stained rocks in the Triassic sandstones. Taylor's copper mine is mentioned by Professor Rogers, who says, "though opened with high expectation of profit, has long been abandoned."
COPPER. 619
Eeferences.
Boyd, C. R. The Mineral Wealth of Southwestern Virginia.
Transactions American Institute of Mining Engi- neers, 1876-77, V, 81-92.
The Mineral Resources of Southwestern Virginia. Transactions American Institute of Mining Engi- neers, 1879-80, VIII, 338-348.
The Utilization of the Iron and Copper Sulphides of Virginia, North Carolina and Tennessee. Trans- actions American Institute of Mining Engineers, 1885-86, XIV, 81-84.
Fontaine, Wm. M. Notes on the Sulphuret Deposits of Virginia. The
Virginias, 1882, III, 154-166.
Moxham, Edgar C. The "Great Gossan Lead" of Virginia. Transactions
American Institute of Mining Engineers, February, 1892, 6 pages.
Phalen, W. C. Copper Deposits Near Luray, Virginia. Bulletin No.
286, U. S. Geological Survey, 1906, 140-146.
Watson, Thomas L. Copper-Bearing Rocks of Virgilina Copper District,
Virginia and North Carolina. Bulletin Geological Society of America, 1902, XIII, 353-376.
The Copper Deposits of Virginia* The Engineer- ing and Mining Journal, 1906, LXXXII, 824-826.
Watson, Thomas L. and Weed, Walter H. The Copper Deposits of Vir- ginia, Bulletin No. IV, Virginia Geological Sur- vey. (In press.)
Weed, Walter H. Types of Copper Deposits in the Southern United
States. Transactions American Institute of Mining Engineers, 1901, XXX, 449-604.
Copper Deposits of the Appalachian States. Bidletin No. 213, U. S. Geological Survey, 1903, 181-186.
Weed, Walter H. and Watson, Thomas L. The Virginia Copper Deposits.
Economic Geology, 1906, I, 309-330.
Rogers, Wm. B. A Reprint of the Geology of the Virginias, 1884, 832
pages.
520 MINERAL RESOURCES OP VIRGINIA.
m. znrc anb lead.
Historical.
The first authentic records of lead mining in Virginia date back more than 150 years, and the old lead mines at Austinville on New river, in Wythe county, were the first to be worked. Colonel Chiswell, a native of Wales and one of the earlier adventurers in southwestern Virginia, was one of the first operators of the Austinville mines. ChiswelPs operations at Austinville commenced in the year 1750 and closed shortly after the beginning of the Revolutionary War in the year 1776, covering a period of about 25 years. From that time to the present mining has been carried on almost continuously in the Virginia area.
For many years after the Virginia mines were operated, mining was confined exclusively to the lead ores. The zinc ores seem not to have been recognized at the Austinville mines until sometime during the Civil War, when several tons were shipped to the smelting works at Petersburg.
Zinc ores were first discovered at Bertha near Austinville, in Wythe county, during the year 1886. Mining of zinc ores in Virginia properly dates from the opening of the mine at Bertha in 1879, at which time a small shipment of ore was made to Providence, Rhode Island. The metal obtained from these ores proved to be of such rare purity that attention \7as directed at once to them and a smelting plant was built at Pulaski, which was later remodeled and enlarged and is owned and operated at present by the Bertha Mineral Company. The "Bertha" spelter is of exceptional purity and has a world-wide reputation.
Much if not most of the ores yielding the lead made into bullets, for use by the Confederate soldiers in the Civil War, was produced by the Virp^inia mines, principally those of Wythe county, with some from the mines near Faber, in Albemarle county. Ore was first discovered on the property near Faber in Albemarle county in the year 1869.
Distribntion.
Excepting the single deposit in the extreme southwestern part of Albemarle county, the known commercial deposits of lead and zinc in Virginia are limited to the Valley province, west of the Blue Ridge. All mining and prospecting for lead and zinc ores in this province have been confined to the western half, extending from and including Roanoke county on the east to and including Scott coimty on the southwest. Ores, both of lead and zinc, are known to occur either sparingly or in quantity
ZINC AND LEAD.
621
in the following southweEtera counties of the State: Roanoke, Mont- gomer}', Pulaski, Wj-the, Smyth, Bland, Tazewell, Kussell, and Scott. Of this number only one county, Wythe, has shown as yet producing mines. More or less prospecting has been attempted in a majority of the counties named above and very small amounts of the ore have been mined in a number of them.
Geologically the occurrence of lead and zinc ores in southwest Vir- ginia is limited to the magnesian limestone of Cambro-Ordovician age, known as the Shenandoah or Valley limestone. The known commercial
Fi^. 89. — Map of southwest Virginia and east Tenneaaee, shoving distribu- tion of lead- and Eioc-orea. Lead- and zinc-depoaitH indicnted by heav; dots. Scale, 1 inch = 120 miles. (After Watson, Trans. A. I. M. E.)
deposits of these ores occur near the eastern side of the Valley though several promising prospects are opened near the western side. Map, figure 89, shows the location of the principal opoiings worked for lead and zinc in southwest Virginia and east Tennessee.
General Geology.
Only those features of the general geologj', which are essential to the nnderstanding of the ore-deposition, will be considered here. The rocks included within the limits of the zinc and lead region of Virginia-Ten- nessee range from Lower Cambrian to Carboniferous in age. They are. without exception, of sedimentary origin; and include shales, sandstones.
522 MINERAL RESOUBCES OF VIBGINIA.
conglomerates, and limestones, presenting considerable variety in compo- sition and in appearance. They have been more or less metamorphosed, and in consequence are considerably changed, as a rule, both lithologically and structurally.
The ore-bearing formation in Virginia is the Shenandoah limestone, of Cambro-Ordovician age. The formation is a magnesian limestone, dark to light gray or nearly white in color, usually fine-grained and massive, and containing much chert distributed through parts of it in the fonn of nodules and layers. Wide variation in composition is noted from shght siliceous marble to calcareous sandstone.
Folds and faults characterize the entire area of the Great Valley of the Virginia-Tennessee district. The folds have a general trend paralleling approximately the axis of the Valley, which is noriiheast-southwest in direction. The dips on the western side of the anticlines are frequently veri;ical, and in places overi;umed, and many of the folds have been com- pressed until broken. The usual dip on the southeast side of a fold is from 30° to 45® to the southeast. The faults are associated with the anticlinal folds, the breaks occurring usually on or near the noriihwestern side of the anticlines. The faults are of the overi;hrust type, with the fault-planes usually dipping from 30** to 50° southeast, with an estimated displacement, by Keith, in some of the faults of the Tennessee area, of nearly 3 miles. The faulted zone is usually characterized by much brecciation, and it is along these zones that localization and concentration of the load- and zinc-ores have taken place.
The Appalachian Valley has been a land-area since early Mesozoic time, during which time the field-evidence indicates several periods of uplift, followed by intervals of quiescence. The periods of quiescence, which followed each uplift, were sufficiently long to enable the streams <o establish a system of base-levels over the entire r^on, and the region was also stationary for a time sufficient to admit of the interstreara areas being lowere<l to an approximately uniform level. The harder and more resistant rocks, such as sandstone and quartzite, were nev?r eiitliely reduced, but they mark partly unreduced residuals, which stand in relief above the general level of the erosion-plane.
Accordingly, evidence favoring several periods of base-leveling and planation is recorded over the area. The oldest and most extensive peneplane was probably formed in Cretaceous time. Subsequent uplifts were followed by shorter periods of quiescence, which record other pene- planes cut during the Eocene and Neocene periods.
ZINC AND LEAD. 523
The Ores and Associated Minerals.
The ores include (1) the original sulphide forms sphalerite, sulphide of zinc, gelenite, the sulphide of lead, pyrite, the sulphide of iron, and in several places chalcopyrite, the double sulphide of iron and copper; and (2) the secondary or oxidized forms which have been derived from the original sulphides and occur in the residual decay of the limestone. These include calamine, hydrous silicate of zinc, smithsonite, carbonate of zinc, and cerussite, carbonate of lead.
The associated non-metallic minerals, named in the order of their importance, are dolomite, calcite, barite, fluorite, and quartz. Of tiiese dolomite and calcite constitute the principal ones and they occur in vastly the largest amount. Barite, fluorite, and quartz are not always present but are confined to several of the mines in southwest Virginia.
The Lead Ores.
Odlenite, — The principal occurrence of galenite is in association with the zinc ores in the zinc mines. At the principal Virginia zinc mines galenite occurs in fairly large amounts in intimate association with sphalerite. Its usual occurrence is granular and massive-granular less frequently in the form of crystals. Selected specimens from the Austin- ville mines in Wythe county gave the following results on analysis:
Per cent.
Lead 73.89
Iron 0.22
Zinc 9.31
Sulphur 16.20
Silica 0.54
Total 100.16
eqniyalentB in
PbS 85.29
ZnS 13.87
FeSa 0.46
Cerussite. — This mineral has been found in more than a trace only at the Austinville mines in Wythe county, where it is not altogether an uncommon ore among the altered forms. It occurs distributed through the residual clays of the limestones as stringers and small irregular masses. The earthy form greatly predominates, the clayey admixture being readily identified by its weight. Crystals grouped in clusters and aggregates of white and light grayish color distributed through the clay are not uncom- mon. It also occurs as white powder-like coating on the crystals and masses of granular galena.
524
MINERAL RESOURCES OF VIRGINIA.
The Zinc Ores.
Sphalerite. — This mineral, forming the most important ore over much of the Virginia area, was the original zinc mineral from which the secondary zinc ores concentrated above ground water-level have been derived. It is found usually below the ground water-level, and in some of the mines not yet worked to this depth it has been found but sparingly. It varies in color from yellow, through brown to nearly black, the black color being due to impurities, particularly iron. In some of the larger mines sphalerite is associated with much galenite in places, some pyrite and very occasionally with scant chalcopyrite.
The sphalerite occurs in the form of disseminated graiui?, masses and stringers in the magnesian limestone and similar form, but mostly as stringers in quari:z-fluorite lenses intercalated in a talcose schist in Albe- marle county. At Cedar Springs, Wythe county, and Rye Valley, Smyth county, the blende is of exceptional purity, as indicated in the analyses below. It is of yellow color, massive in form, with perfect cleavage, but not preserving outward crystal form. Analyses made of the blende in the laboratories of the Virginia Polytechnic Institute on selected pieces col- lected by the writer from the mines in Albemarle, Wythe, and Smyfli
counties gave:
Wythe county Wythe county Smyth county Albemarle
Austinville Cedar Springs Rye Valley county
Per cent. Per cent. Per cent. Per cent.
Zinc 65.01 66.76 66.94 62.11
Sulphur 31.93 33.44 33.26 34.45
Iron 1.94 0.50 0.30 3.44
Lime 0.08 trace trace 0.05
Magnesia none trace trace none
Silica 0.33 0.10 0.08 0.20
Total 99.29 100.80 100.58 100.31
'^^"^\ . , } 99.94 99.56 99.86 92.70
Smiihsonite, — In some of the mines smithsonite forms a fairly im- portant ore of zinc. It occurs in the residual clays derived from the magnesian limestone concentrated, usually, in the bottom portions of the clays and resting immediately on the irregular weathered surface of the limestone, as shown in figures 90 and 92. It is intimately associated with calamine.
Smithsonite occurs both in the granular and earthy forms, principally the latter, as crystalline incrustations, and as a porous or spongy material with the cavities frequently filled with the powder\^ and earthy form of the ore. In color it varies from light gray through yellow to brown accordiug to the impurities present.
ZING AND LEAD. 525
The calculated amoimts of smithsonite and calamine^ from analyses made by F. P. Dewey, on specimens of the ore of the Falling Clii! zinc mine at Bertha, Wythe county, gave the following results :
Per cent. Per cent.
Smithsonite 75.52 70.99
Calamine 22.22 12.05
Calamine, — This mineral formed originally the principal secondary ore of zinc mined in the district. It is much more abundant than smithsonite. In occurrence it is closely similar to that of smithsonite with which it is intimately associated. It is indeed very diflBcult and in some cases impossible to separate the two ores, so intimately admixed are they.
Calamine occurs in the residual clays, usually in the bottom portions, immediately on and next to the irregular weathered surface of the under- lying limestone, as shown in figures 90 and 92. Beautiful white incrusta- tions of the mineral presenting mammillary and stalactitic surfaces have been observed in places between layers of the more solid massive ore. Granular masses and honey-comb forms of calamine were quite common. Much of the calamine formerly mined at Bertha, in Wythe county, is re- ported to have been in sheet-form, rarely in contact with the limestone but concentrated several inches away from the limestone surface and having the intervening space filled with a mixture of loose powdery calamine and smithsonite.
The following chemical analyses of specimens of calamine from the mines of Wythe county, indicate the general character of the ore :
I II III
Per cent. Per cent. Per cent.
Zinc oxide 67.88 67.42 67.15
Silica 23.95 25.01 25.33
Water 8.13 8.32 7.47
Total 99.96 100.75 99.95
Specific gravity 3.338 3.40
I. Maclrby. Chemical News, 1873, XXVIII, 272.
II. Genth, F. H. Proceedings of the American Philosophical Society, 1885, XXXIII, 46. III. Jones, A. Journal of the American Chemical Society, 1892, VI, 620.
Calculated amounts of calamine and smithsonite from analyses made by F. P. Dewey on specimens of the ore from the Falling CliflE zinc mine at Bertha, Wythe county, gave the following results:
Per cent.
Calamine 88.52
Smithsonite 3.26
526 MINEBAL RE80UB0ES OF VIBGINIA.
'^BiLckfat" — "Buckfat^^ is the name applied by the miners to a mixture of clay with the minerals calamine and smithsonite. It is not a defildte mineral but is a lean ore generally too low in zinc to be profitably used in the present practice of smelting. The zinc content shows wide varia- tion, however, ranging oftentimes much higher than given in the analysis below. It is both hard and soft and is accordingly called by the miners **hard buckfat'^ and "soft buckfat." Its separation from the rich ores is effected by hand-sorting and by subsequent washing and jiggiiig. The treatment practiced at the Bertha mines previous to the conversion of the ore into spelter consisted in violently washing "soft buckf at*' in water and crushing and jigging the 'Tiard buckfat."
Heyward gives the following analysis of a zinc-bearing clay from the neighborhood of the Bertha mines:
Per cent.
Silica 37.38
Alumina 24.67
Ferric oxide 6.34
Zinc oxide 12.10
Magnesia 0.27
Potash 0.47
Soda 0.27
Water 100° C— 6.69
Water 100*» C.+ 10.35
ToUl 98.54
Associated Ores.
Over the southwest Virginia area iron-ores and manganese-ores, especially the former, are very abundant in some of the larger zinc mines. The iron-ores have been somewhat extensively mined in some places and in several instances mines formerly worked for zinc ores are now being worked for iron. Pyrite is rather a frequent associate of galenite and sphalerite in some of the mines. It occurs in the fresh limestone below the belt of oxidation. It is by no means uniformly distributed through the rock, but in places it is sufficiently concentrated to be noticeable, and rarely, if ever, is it present in quantity large enough to be hurtful to the lead and zinc ores. Limonite comprises the principal iron ore mined in association with the zinc ores. Hematite is less common than limonite. Black oxide of manganese is a frequent associate in some of the mines.
Associated Minerals.
Named in the order of their importance, the associated minerals arc dolomite, calcite, fluorite, quartz, and barite. Of these dolomite and
ZING AND LKAD. 5\}T
calcite comprise the dominant minerals, with some barito and leas fluorito« Fluorite and quartz make up the gangue minerals at the z.no and load n\ino in Albemarle county. Calcite occurs only sparingly at this mine wl\ile fluorite is the dominant mineral. Over the southwwt Virginia area dolomite and calcite fill fractures between the magnesian limestone frag^ ments in the form of crystalline masses, forming a limestone bnx»cia. The relative proportions of cement (recrystallixcd calcite and dolomite) to rook fragments vary widely. Numerous analyses of specimens of the calcite and dolomite collected over the southwest Virginia district gave nearly pure calcium carbonate for the former and a ratio of calcium to nuvufnosium of 1 :1 for the latter, which is the ratio of normal dolomatc. The fluorito found at the Albemarle county mines is usually of white color though the violet shade is fairly common, which latter is sparingly found at several localities in the southwest Virginia zinc mines.
Alteration of the Lead and Zino Ores.
The important secondary ores comprise colamine, smillisoniio, and cenii<site, which have been derived from the original fuilphidcs, Kphiilcrito and galenite, by the usual processes of weathering. Until rorontly only the oxidized or secondary ores have been mined, but f)roparaiion Ih now being made to mine the original sulphide ores in the fresh limcstono.
Mode of Ooonrrenoe.
The sulphide ores, — The bulk of the sulphide ores belong to tho disseminated replacement breccia type. As a rule the process of replace- ment has played an important part in the ore formation, but in some instances very little replacement of the limestone by the ore is indicated. In the latter case the ore would be more properly designated a straight breccia tpye in which practically no replacement has occurred. On the other hand the ore has originated at several ploceq largely through a replacement process.
The breccia is usually made up of sharp-angler] fragments of the country-rock, magnesian limestone, cemented by a matrix of white crystal- lized calcite and dolomite and blende, with or without replacement of the limestone fragments. The breccia-zones are associated with faulting and folding. Xot all parts of the breccia-zones are minerali7/jd, but the ore is distributef] at somewhat irregular interval.^. WlKrre minera lizard and so far as can be judged from developments the ore continufn with dej^th.
528 MINERAL RESOUBCES OF VIROIKIA.
When occurring in the same mine the blende and galenite are inti- mately admixed. Many parts of the limestone, both small and large, show all blende with only here and there sparing dissemination of galenite through the rock, closely intermingled with the blende. Other parts of the limestone usually much smaller in area show a preponderanoe of galenite with little or no disseminated blende. The same relation holds true for the very small amount of pyrite present in the rock which may be intermingled with the galenite or blende or both.
The oxidized ores, — ^Where sufficient developments have been made^ as in the mines of Wythe county, the oxidized ores usually show much richnesB and they are often concentrated in massive form as large irr^;iilar masses and layers. This is especially true of the calamine which fonns the dominant oxidized ore. So massive was the calamine in places in the dd Bertha mines that blasting is reported to have been necessary at the time for its removal.
Concentration of the oxidized ores has taken place principally at and near the bottom of the residual clays, closely hugging the irr^;nlar weathered surface of the limestone, as shown in figures 90 and 92. Frequently several inches separate the massive form of the ores, calamine and smithsonite, from the limestone. This space is filled oftentimes with a loose, p«)wden' mixture of the two ores. At times the partly decayed limestone in pul- verulent granular form partly or entirely fills the space. Much galenite is intermingled in places with the concentrated calamine and smithsonite in the lower portions of the clays. Usually when associated with the oxidized ores in the way mentioned the galenite is observed to diminish in quantity upward more rapidly than the calamine and smithsonite.
Smithsonite, which is present in much smaller quantity than calamine, is ordinarily admixed with the calamine and the two concentrated in the basal portion of the clays next to the limestone surface. Cerossite occurs largely in stringer form penetrating the clays and as a coating on the nodules and masses of galenite. These stringers vary much in thicknesa and extent but in the larger ones a nearly vertical position in the clays is often assumed.
As a rule the residual clays are highly ferruginous. Ldmonite com- poses the principal part of the clays in some of the mines and it was derived in part at least from the oxidation of the original pyrite dissem- inated through the limestone in association with galenite and sphalerite. It is usually of good grade and several of the mines formerly worked for zinc ores are now being worked for iron ore. The relations between the ores, the limestone and the clays, as described above, are shown io figures 90 and 92.
HINKKAL RKS)OrR('B»
LIMESTONE WEATHEUlNXi. 7.1SC MISER. WYTHE COl'NTY, VIRGINIA.
* •. '
I
ZINC AND LEAD. 529
Belation of the Ores to Oeolog^o Stmctnre.
The lead and zinc district of the Great Valley region of Virginia- . Tennessee is one of intense deformation — folding, faulting, and brecciation. Moreover, the localization and concentration of the ores follow closely these structural lines. Mineralization has not taken place through all parts of the breccia-zones which follow the anticlines, but only along some of the zones in places and at irregular intervals have the or(*s accumulated. Wherever the ores have been found they hay© been tioted in some part of an anticlinal fold in or near a faulted bireccia-zone. The ores are accord- ingly of the breccia type, as shown in figures 94, 95, and 96. At Austin- ville, Wythe county, the ores appear in well-defined ore-bodies which have resulted largely from a replacement process, mostly where the joint and bedding planes of the limestone intersect and on the limb of a faulted anticline.
Origin of the Ores.
The statements here made concerning the genesis of the zinc and lead ores apply only to the Great Valley region of Virginia and Tennessee. So far as known there are no igneous intrusions found within the limits of this region with which to connect the ores. There appears no good reason for regarding the ores as having been derived from profound depths as indeed the evidence is against this source of the material.
The field evidence favors the original deposition of the ores in the Cambro-Ordovician limestone in disseminated form, but so very sparsely disseminated as to render subsequent localization and concentration of them by underground waters along certain structural lines, previously indi- cated, in their present workable form. In some of the Virginia deposits the ores are intimately associated with the more carbonaceous layers of the limestone, which indicates that the ores were probably introduced as sulphates and were reduced by the organic matter in the limestone and deposited as sulphides.
In addition to the sulphide cycle, it seems probable that there was a second or sulphate cycle, in which the metals were transported as soluble sulphides and were deposited as such. This was pr6bably the process of deposition at Austinville and in some other of the Virginia deposits. Many of the deposits show little or no replacement of the limestone substance by the ores. The mingling of the ore-bearing solutions with other solutions in the faulted breccia-zones, and the reaction of the ore-bearing solutions
530 MINERAL RESOURCES OF VIRGINIA.
on the wall-rock, limestone, largely resulted in the precipitation of the ores, where not connected with reduction and precipitation by organic matter.
Description of the Mines.
The production of lead and zinc ores in the State has been almost exclusively from the Valley region of southwest Virginia, The ores have been worked in the following counties of the Valley region: Botetourt, Roanoke, Montgomery, Pulaski, Wythe, Smyth, and Hussell. Of these Wythe has been the important producing county. Work in the other counties has been largely in the nature of prospecting.
THS GREAT VALLEY &EGIOH.
Boanoke and Botetonrt Counties.
Ores of zinc and lead have been opened at two places in the vicinity of Hoanoke City, namely, on the Martin property 2% miles southwest of Hoanoke City, in Hoanoke county, and just across the county-line in Botetourt, a half mile northeast of Bonsack station. The openings on both places are of long standing and will not exceed 50 feet in depth. The developments here comprise some half dozen small openings in the lime- stone.
The Martin prospect, — An examination of the dumps at the openings showed the occurrence of the sulphides of lead, zinc, and iron in close association. No ore was seen in place.
The Bonsack prospect, — The development consists of a single shaft less than 50 feet deep. At the Bonsack prospect the dump showed some p}Tite, a little chalcopyrite and sphalerite, the former predominatiDg. So galenlte was noted. Neither of these properties has passed beyond the prospecting staffe.
Ifontgomery County.
More or less prospecting for zinc and lead ores has been done in a number of places in this county, but as yet no productive areas of the ores have been found. The localities at which prospecting has been done are as follows: In the extreme southwestern pari; of the county on Bon/s creek; several miles southeast of Shawsville on the Langhom estate; on the Walker and Vaughn properties south of the Norfolk and Western Eailway between Shawsville and Big Tunnel; about 2 miles south of Christiansburg ; and on the Cloyd property on New river, about 8 niilea south of Blacksburg.
ZIKO AND LBAD. 531
Pnlasld County.
The known occurrence of zinc ores in Pulaski county is limited to the extreme southwestern part of the county, near the Wythe county line and in the vicinity of Allisonia and Delton along New river. The ore com- prises zinc blende occurring in the unaltered limestone and the oxidized ores, calamine and smithsonite, concentrated in the residual clay derived from the limestone. Openings have been made at 3 places only, one of which has produced ore in sufficient quantity to be workable.
The Delton mines, — The Delton mines are located about one mile soutb of Delton and about the same distance west of New river, where crossed by the Cripple Creek branch of the Norfolk and Western Railway. These mines were opened by the Bertha Mineral Company in May, 1902, and were continuously worked until December, 1903, when it is claimed that the ore pinched out, about 8,000 tons of ore having been mined. The entire output from these mines was of the oxidized ores, comprising zinc silicate, calamine, and zinc carbonate, smithsonite. After concentration the product contained 40 per cent, metallic zinc, 0.5 per cent, lead, and 5 per cent. iron.
The Forney openings. — Two openings were. made in the limestone, several years ago by Mr. B. S. Forney, on the opposite side of New river from each other and about one mile northeast of Allisonia. The op^iing on the south side was a shaft sunk to an unknown depth, and that on the north side of the river comprised a tunnel driven into the limestone slope at an elevation of about 300 feet above the river level. Beautiful specimens of light yellow zinc blende were noted on the dump at the tunnel. Zinc blende was observed in the limestone in the bed of New river, during the construction of a coffer dam across the river, at a position nearly oppositr; the shaft and timnel on the two sides.
Wythe County.
Wythe county has been and is at present the main producing county of lead and zinc ores in Virginia. At least nine-tenths of the lead and zinc ores produced in the State has been from the Wythe county mines. The mines at Bertha and Austinville in the extreme southeastern corner of Wythe county have produced practically the entire output in these ores. It was here that the first mining of lead and zinc ores in the State was done, dating back more than 150 years. Until about 2 years ago the ores mined included the oxidized forms concentrated at only slight depths
532 MINERAL RESOURCES OF VIRGINIA.
below the surface. Recent exploitation below this level has developed the presence of original sulphide ores in the fresh rock, which, at Auatinville, appear to be sufficiently concentrated in places to be workable. At Cedar Springs, 22 miles west of Austinville, and in the southwest corner of Wythe county, zinc blende is being mined and milled.
The ores mined include calamine, smithsonite, sphalerite, galenite, and cerussite. Pyrite occurs sparingly in some of the mines in asBodation with sphalerite and galenite.
The Bertha Zinc mines, — The old Bertha zinc mines, located abont one mile south of Bertha, a station on the North Carolina extension of tlie Norfolk and Western railroad and 20 miles southwest of Pulaski, have produced a larger quantity of zinc ores than any other mines in the State. These mines were regularly opened in 1879 and were systematically mined for zinc ores until 1898, since which time the property has been worked for iron ores by the Pulaski Iron Company. The annual output in rinc ores from these mines was large and comprised only the oxidized fonns, silicate and carbonate of zinc. Mining was confined entirely to the residual clays between and around the limestone chimneys, with a depth in some places of nearly 100 feet. (Figure 90.) Plate LXXVI, figures 1 and 2, are views of the limestone chimneys in the Bertha mines after the stripping of the residual clays. Figure 91 shows the relations of the soft ore to the limestone chimneys and the residual clay, and the method of mining the ore.
The Austinville Lead and Zinc mines, — The Austinville Lead and Zinc mines, owm'd by the Bertha Mineral Company, are located in the south- eastern corner of Wythe county, '29 miles southwest of Pulaski by rail and 10 miles west of the Bertha mines described above. They are further located about a quarter of a mile south of New river on the limestone ])lateau, at an clovalion of 290 feet above the river. These mines were first worked more than 150 years ago when lead ores were mined by Colonel Chiswell, in 1750. The ores occur in a metamorphosed zone along the southeast limb of an anticline, which trends northeast-southwest and is cut through by New river at this point. The limestone along this zone ha* been cnislu^l and broken and cemented, and, in many places, recrystalli^- So extensive has been this metamorphism in places that the original lime- stone bedding is obscured. In many places, however, the bedding planes are sharply defined, dipping on an average of 45° southeast. Jointing i' rather strongly emphasized in the limestone at the mine openings.
UINBRAL UESOrnCES OF VIRGINIA.
ri.ATK l.XXVII.
LIMESTONE WEATHER1N(;, ZIKC MINES, WYTHE COUNTY. VIRGINIA.
\
ZINC AND LEAD.
HINE&AL RB80DB0EB OF VIBOINIA.
ZINC AND LEAD.
536 MINERAL RESOURCES OF VIRGINIA.
Until recently the ores mined at Austinville were of the oxidized type, concentrated for the most part near the bottom of the residual clays wi tlie irregular surface of the limestone, as shown in figure 92. Plate LXXVII, figure 2, is a view of the weathered limestone surface at the Austinville mines, in which the bedding is obliterated by the recrystallitt- tion of the limestone. The soft ores mined included the silicate and ca^ bonate of zinc and the carbonate of lead. Much galena^ lead sulphide, was associated in places w ith the oxidized ores. During the early period of mining the ore was largely won by open cut mining. The lead ores were then followed down by stoping when found. At that time the flue (^ei were discarded.
Considerable underground work has been done in the fresh limestone,
and the Bertha Company has been largely engaged, during the part aeiveni
years, in exploring and developing the original sulphide ores in the fieBh
rock. The sulphide ores include zinc blende, galena, and some pyrite, all
more or less closely associated. In some places, zince blende predominatea
with a little galena and less pyrite, and in others, galena predominates with
but little blende and pyrite. Pyrite, as a rule, is not abundantly distributed
through the limestone and is not in quantity sufBcient to be harmful to
the ores of zinc and lead. The purity of the zinc blende at the Austinville
mines is indicated in the following analysis, made by Mr. J. H. Gibbonej»
on selected pieces collected by the writer:
Per cent.
Zinc 65.01
Sulphur 31.98
Iron 1.94
Lime 08
^lagnesia none
Silica 38
Total 99.29
Zinc sulphide 96.94
As sliown in figure 03, a sketch map of the Austinville mineB, mining of the orts lias been by open cuts, shafts, and tunnels. The ores have been worked on 3 principal levels at the following depths below the surface?: 90, 180, and 238 feet. An elaborate concentrating plant for milling the ores is in operation at the mines. In addition to this milliBg plant, oxide furnaces have been built, which utilize all tailings and low c^rade ores that formerly were claimed not to be usable, and therefore were discarded. Tlie oxide furnaces supply a zinc oxide which averages from 70 to 80 per cent, zinc, used for charging in the smelting fumaceB at Pulaski for making spelter.
MINERAL RESOURCES OF VIRGINIA.
PLATE LXXYIII.
Fig. 1. — Zinc milling plant of the Bertha Min
:-n
k • ■
__ .„ ..)
ZINC AND LEAD.
537
Not only are the zinc and lead ores mlDed at AustiiiTille, but the waste } washed for iron and the ore shipped to the iron furnaces, and the lime- tone of the chimneys of the open cuts is quarried and nsed for fluxing, bos utilizing practically everything.
Fig. S3. — Sketch map of the Austinville lead and z tion and general character of workings, and tin- ■tone and limestone.
538
UINERAL RB80ORCK8 OF TIBQINIA.
The New Biver Mineral Companjf't mines. — The mines of the New River Mineral Company, located near Ivanhoe, have been extensively worked for limonite or brown iron ore. Much zinc ore, comprising cala- mine and smithsonite, is reported to have been mined from these openings, from time to time, in winning the iron ore. Similar conditions are re-
cALcrre AHDDOionrTE
Fig. 04. — Limestune breccia from Cedar Springs, Wythe county, showing relations of eplialn- itc to ca I cite- dolomite fllling and to the limeBtone. Some replacement of the )jinestoD« ii ahown. Natural size.
ported to have obtained in the Simmernian iron ore pita nearby. The zinc oreB mined are reported to have been shipped to Trenton, New Jersey.
The Cedar Springs Zinc mines. — The mines of the Cedar Springs Zinc Miiiinjr and Development Company are located in the extreme southwest corner of Wythe county, about 5.5 miles south of Rural Retreat on the main
ZIKC AND LEAD.
539
line of the Norfolk and Western Railway, The property comprises 387 acres of land, located along the headwaters of Cripple creek, on which nnmerouB openings are made, extending from Cedar Springs eastward for a distance of one or more miles. The openings comprise oprai cute, shafts and tonnela, and in addition to these some drilling haB been done, the deepest of which reached a depth of S50 feet. The ore ie of the breccia type composed of zinc sulphide, practically, without galenite and pyrite. (Figures 94 and 95.) The blende is in massive form, of light yellow color, and is of exceptional purity, ae shown in the analysis made by Mr. J. B. £off, Jr., on pieces collected by the writer:
Per eeot
Zinc 86.76
Sulphur 33.44
Iron J»
Insoluble nwtter \
Calcium carbonate I < a
Munwium carbouate f "^'
Water 110' C. J
Lead )
Sdmiumi ■^«
Total 100.70
Zlno nilphid« 99.63
|5P«AIim[^aU0IIITE |i^UHE5T0H[[:^ ^&m.
S40 MINERAL BE80URCEB OF VIRGINIA.
A commodious concentrsting plaat bas recently been built at the mines by the company for concentrating and milling the ore.
Smyth County.
Much prospecting for zinc ores has recently been carried on in Rve Valley in the south central portion of Smyth county. Operations hare been almost exclusively confined along the South Fork of the Holston riier in Eye Valley, extending in a general east-west direction.
The Rye Valley Mining Company's mine*. — The largest operation in the county is that of the Bye Valley Mining Company, the mines of which
Fig. se. — Sketch showing relations of uphalprite and pileon to fluorspar and caleite-doloniite. Kye VhUpv Mineral Com- j)an_v, Sugar Grove, Smyth county, Virginia.
are located a quarter of a mile north of Sugar Grove post-office, and about 200 yards from and on the north side of the South Fork of the HoIsiod river. The openings comprise 2 main shafts and a number of small t«t- pita. The depths reached by the shafts are 100 and 300 feet respectivelv. on the dip of the rock, 60° southeast. The shafts are connected under- ground by a drift at the 100-foot level. The ore is chiefly galenite, leaii sulphide, with zinc blende in close association at the bottom of the 300-foot shaft. (Figure 96.)
The total production from this mine is reported at about 25 carloads ol ore, which nns hand picked, there being no concentrating mil! on thi! property.
Other properties in Smyth county, which have been considerably pros- pected hut which have not yet produced ore. are: The CaJhoim. located
ZINC AND LEAD. 541
about 2 miles west of Sugar Grove post-office ; the Virginia Lead and Zinc Company on the Scott place, located about one mile south 80*" west from the Calhoun openings ; the Livesay, situated about 2.5 miles south 70** west from the Scoit openings; the McCarter place, located about three-quarters of a mile southwest of the Livesay place; the Martin prospect, located about 4 miles north 80° west of the McCarter openings; and the Van Hoy prospect, located about one and three-quarter miles south 80° east of the Martin place.
The openings on the above places comprise in part shafts, open cuts, pnd pits, some of which have been dug to a depth of 60 feet and more. An examination of these during the spring of 1905 showed, at that time, fairly encouraging indications of workable zinc ore on several of the properties.
On the Scott place the blend closely resembles that described above at Cedar Springs, in Wythe county. An analysis of selected pieces of the ore from this place, collected by the writer, gave Mr. J. H. Gibboney the fol- lowing results :
Per cent.
Zinc 66.94
Iron 30
Sulphur 33.26
Silica 08
Lime trace
Magnesia trace
Total 100.58
Zinc sulphide 00.86
Bussell County.
Zinc ores have been mined at only one locality in Russell county, namely, en Copper creek, about 7 miles south of Castlewood, a station on the Clinch Valley division of the Norfolk and Western Railway. Developments have thus far been entirely limited to the Oshorn place, although ore is re- ported on several of the adjoining properties. The developments include one large main pit and numerous small test-pits, with an average elevation above Copper creek of about 350 feet. The property has been worked at several different times by different parties, and much money has been spent in developing it. The ore comprises calamine, sphalerite, and some admixed galena. The chief difficulty in mining this ore is the distance from the railroad and the rough mountainous area over which the ore must be hauled for shipping.
MIXERAL RESO0BCE8 OF TIROrNl
THE FIEDXOin; OS CEYSTALLIVE K
Albemarle Coonty.
The single dcpoeit of lead and zinc ores in Albem only tj'pe of its kind yet known in the south. The Albemnrlc 7Anc and Ivcad Company, and is located S
Kifj, 1)7. — .Spei'iaien from fluors[jnr Icnn, allowing ilietril pliide minerals, sphalerite and galenite. Albenmr. Campn-ny'a mine, near Faber. About one-third ni
ea.«t of Faber, a station on Ihc Southern Railway, in I foot-hills. The main developments t-omprist' 3 shaft depths of 25, 50, and 120 feet, and separated by a d feet between the two extreme shafts. In addition t(
ZING AND LEAD. 543
level has been run into the ridge from the valley bottom, and a cross-cut lun from the adit on and along the vein for a distance of 140 feet.
The rocks in which the lead and zinc ores occur are metamorphosed crystalline schists, cut by a series of basic igneous rocks of the diorite and diabase tjrpes. The metalliferous vein is traced for a distance of several miles. It is of variable width, with an average of 4 feet; the strike is north 46*" east, exactly paralleling the diorite dike 26 feet distant, on tbj northwest side; and it dips 80® to 86*" northwest. Where opened the vein is of the lenticular type, composed of bulbous bodies of fluorspar mixed with some quartz, through which the ore, blende and galena, is distributed.
The ore, consisting of blende and galena, occurs chiefly in the fluorspar lenses, although the schists next to the lenses is often more or less min- eralized. Figure 97, a drawing of a large mass of the ore-bearing fluorspar- quartz broken from one of the lenses, illustrates the typical occurrence of the ore. Some chalcopyrite and smithsonite occur in addition to the principal minerals, blende and galena. Cerussite and azurite were reported Kome years ago from the dumps. The galena is argentiferous, and arsenic and antimony are reported in very small quantities. Fluorspar is the principal gangue mineral.
Specimens of the mineral collected by the writer gave Mr. J. H. Gib- boney the following results on analysis :
Per cent.
Zinc 62.11
Iron 3.44
Sulphur 34.45
Lime 0.05
Silica 0.26
Total 100.31
Zinc sulphide 92.70
The following analysis was made by Professor W. H. Seamon on a sample of the ore collected by him and believed to represent an average of
the vein at that time:
Per cent.
Zinc 32.00
Lead 4.02
Iron 1.88
Calcium 9.09
Insoluble residue 2 to 3 oz.
Copper trace
Arsenic trace
Through the kindness of Mr. Wilkens U. Greene, Mining Engineer in
544 MINERAL B£S0UaC£8 OF VIBQINIA.
charge of the plant, several bags of the lead and zinc concentrates were sent to me and were separately analyzed with the following results:
Lead Zinc
concentrates concentrates
Per cent. Per cent.
Lead 63.05 6.02
Zinc 12.12 47.88
Iron 3.16 7.26
Copper trace 0.94
Sulphur lft.32 29.62
Calcium fluoride 1.31 4.74
Insoluble residue 1.08 2.90
Total 100.04 99.26
Equipment and treatment, — ^The equipment includes a concentrating mill of 80 tons copacity per 24 hours, recently completed; 8 sets of dry jigs ; crusher, dryer, rolls, and screens ; and steam power of sufficient horse- power for operating the entire plant, including hoist, tram-cars, and cable for conveying the ore from the shaft to the mill. Compressed air drill* are used in the underground mining.
The dry process for separating the ore is employed in milling, which diflFers essentially from the wet process in the form of jig used. The Krom jig is used, made of screens of different size meshes, substituting air for water. These can be set to 700 puffs of air per minute. At the Albemarle plant the ore is crushed and sized to pass a IC-mesh screen. All ore above this size is passed back to the rolls and crushed until properly sized. The ore o^oes thence to 4 rough jigs, and from here to 4 finishing jigs. It is claimed that the tailings are practically freed from all ore by this process. If not the jigs can be so regulated as to make a nearly complete separation. The trials so far made at the mill required the jigging process to be re- peated several times on the same ore before a clean concentrate was obtained.
Methods of Mining the Ore.
Until very recently the mining of lead and zinc ores in Virginia was limited entirely to the surface belt of weathering — the residual clays. The mode of occurrence and the character of the ores to be mined demanded the employment of methods used in mining secondary concentrated ores. Accordingly, a system similar to that practiced in mining brown iron ores was employed, modifications being made to meet the changed conditions. Practically all the ores mined are oxidized forms, concentrated chiefly in the lower portion of the clays and are won within a depth of 100 feet. The mining has largely been by open cuts, tunnels and shafts. The
ZING AND LEAD. 545
open cut method differs from that of mining the iron ores in that the former is one essentially of stripping, while in the latter the ores and en- closing clays are mined together and sent to the washer for separation. The open cut method was later changed to that of shaft and drift as shown in figure 91, page 534.
The mining of sulphide ores in the fresh limestone has only recently begun at Austinville, in Wythe county.
Preparation and Smelting of the Ores.
The preparation and treatment of the ore can best be explained by outlining the method used at Austinville. The run-of-mine ore at Austin- ville averages in composition from 28 to 30 per cent, of metallic zinc, from 8 to 10 per cent, metallic lead, and from 8 to 10 per cent, metallic iron. The method of treating the Austinville ore from the time the ore is mined until it is ready for the furnace at Pulaski is, briefly, as follows:
The ore as mined, is carried by trolley to tipples, from whence it is carried by tram-cars to the mill, and dumped on a 4-inch grizzly; thence to a log washer, through a 9x24-inch Blake breaker set at 1.5-inch; and thence to a 14x24-inch corrugated rolls, set at 6 millimeters. From the corrugated rolls the ore is carried to a second log washer, thence to elevator and sizing screens of 6-mm., 2-mm., and 1-mm. mesh, respectively.
The oversize from the 6-mm. screen goes to smooth rolls, 12xl8-inch in size, and is returned to the system or second log washer. The undersize from the 6-mm. on 2-mra. screen goes to the 4-compartment Cooley jigs; Ist hutch and side draw making clean lead ; 2d hutch and side draw, mid- dling, recrushed and returned to the system or second log washer; 3d and 4th hutches, clean zinc. Tails are passed to settling boxes; head of boxes reworked. Lighter material goes to the oxide furnace.
Undersize from 2-mm. on 1-mm. screen goes to the 5-compartmcnt jigs ; 1st and 2d hutches and side-draw making clean lead ; 3d hutch and side- draw, middling; 4th and 5th hutches and side draw, clean zinc. Tails go to boxes.
Undersize from 1-mm. screen goes to 3-corapartment classifier; 1st and 2d draw to 6-compartment jigs; 1st and 2d hutches and side draw, mid- dling; 5th and 6th hutches and side draw, clean zinc. Tails go to boxes.
Third draw from classifier and overflow goes to the 3-compartment double jigs ; 1st and 2d hutches clean lead ; 3d hutch, middling, reworked. Tails go to boxes.
The middlings and tails from all jigs are treated in 4-compartment jigs
546 MINERAL REBOURGES OF VIRQINIA.
as described above. The overflow from Ist and 2d log washer, except the lower end or lighter material, goes to settling boxes, 25 feet long and 8 feet wide; thence to the oxide furnace.
The lead concentrates, averaging lead, 57 per cent.; zinc, 4.8 per cent.; and iron, 3.29 per cent., go to the Scotch hearth furnace, which makes metallic lead and gray slag, the latter averaging lead, 31 per cent.; zinc, 26 per cent.; and iron, 13.3 per cent. This slag goes to the slag furnace, which makes metallic lead and slag, averaging 3.5 per cent. lead.
The zinc concentrates are carried by tram cars from the mill to the separators, where they are put through a revolving dryer to expel moisture and combined water to the amount of 7 per cent. Thence to a water-cooled scraper-conveyor to the top of the building by elevator to sizing screens of 0.5-mm., 1-mm., 2-mm., and 0.25-nim. holes. Oversize from 0.25-incli screen is returned to 12xl4-inch rolls set close. Undersize re-enters the system. From screen to bins, four sizes.
The four sizes, which pass through screens, go to Wetherill magnetic separators, one 4- and one 6-magnet machine ; the smallest sizes going to the smaller machine. Heads from separators, containing iron, 47 per cent., and zinc, from 5 to 7 per cent., are shipped to the iron furnace. The capacity of the mill is about 90 tons of raw ore per day of 10 hours.
Zinc oxide plant, — This plant, consisting of 12 furnaces, has only re- cently been added for the purpose of utilizing the low-grade ore and tail- ings, which were formerly discarded. The grade of ore, including tailings, used for making the oxide will average from 15 to 20 per cent, metallic zinc. The zinc oxide made is sent to the Pulaski furnaces where it is used for making spelter. The oxide made is white, and contains about 4 per cent. of lead, and averages from 70 to 80 per cent, of metallic zinc. The sll^ cessfiil operation of this plant at Austinville is of great importance, since it furnishes a ready method for utilizing low-grade zinc ores, which have elsewhere been claimed not to be profitable for making spelter.
The Bertha Zinc Smelting Plant.
The only zinc smelting plant in the south, located at Pulaski, Virginia, is owned and operated by the Bertha Mineral Company. This plant ^^ built sliortly after the beginning of zinc mining at Bertha, Wythe county, Virginia, in 1879. It was remodeled and enlarged in 1886, and, at present, it consists of 10 large smelting furnaces, ore-sheds or bins, refiners, coal-pJt» engine room, pottery, metal storage houses, and a roasting furnace. Sui-
\ *
MINERAL RESOCBrGfl OF VIROIMA.
PLATR LXXtX.
Fig. 2.— Vii^w of disuiBDtled Einc furnace, Bertha Mineral Company, PuU&lfi- ZINC SMELTING PLANT AND FURNACE. PULASKI. VIRGINIA.
ZINC AND LEAD. 547
ficient railroad trackage is in operation around the plant for shifting the cars ; and a narrow-gauge road is operated between the plant and the com- pany's coal mine at Altoona. Plate LXXIX, figure 1, is a view of the smelting plant.
Spelter.
The high grade spelter made by the Bertha Mineral Company, at Pulaski, has a world-wide reputation. Three grades of spelter are made, branded according to purity : ^^ertha Pure Spelter,'^ *'01d Dominion,^' and "Southern.'^ The "Bertha Pure Spelter^' is sold under a guarantee of 99.98 per cent, of metallic zinc. The following analysis gives an idea of the composition of this grade of spelter :
Per cent.
Zinc 99.981
Iron 0.019
Lead trace
Sulphur trace
Silicon none
Carbon none
Arsenic none
The "Old Dominion^^ brand of spelter contains from 0.2 to 0.4 per cent., and the "Southern" brand from 0.8 to 1 per cent of lead.
Beferences.
Boyd, Chas. E. The Wythe TiCad and Zinc Mines, Virginia. Engi-
neering and Mining Journal, 1893, IV, 661-662, 666.
The Mineral Wealth of Southwestern Virginia. Trans- actions American Institute of Mining Engineers, VIII, 338-348 ; also V, 81.
The Ores of Cripple Creek, Virginia. Transactions American Institute of Mining Engineers, XII, 27- 40.
The Mineral and other Eesources of Southwestern Vir- ginia. The Virginias, 1880, 1, 39.
Case, William H, The Bertha Zinc ]Mines at Bertha, Virginia. Engi- neering and Mining Journal, 1893, LVI, 292-294 ; Transactions American Institute of Mining Engi- neers, XXII, 611-636.
Clerc, P. L. The Mining and Metallurgy of Zinc in the United
States. Mineral Eesources of the United States, 1883, 368-386.
Dewey, P. P. Note on the Falling Cliif Zinc Mine. Transactions
American Institute of Mining Engineers, X, 111- 112.
548
KINERAL RES0UBGE6 OF YIRQINIA.
Dunnington, F. P. Analysis of Aragonite Containing Lead from the Aiw-
tinville Mine, Wythe County, Virginia. Proceed- ings American Chemical Society, II, 14.
Bertha, Virginia, Zinc Ore and Spelter. The Vu> ginias, 1881, II, 147.
Fontaine, Wm. M. Notes on the Geology and Mineral Besonrces of the
Floyd, Virginia, Plateau. The Virginias, 1883, IV, 186-193.
Genth, F. H. Heyward, B. H.
Contributions to Mineralogy. Proceedings American Philisophical Society, 1886, XXIII, 30-47.
On a Zinc-Bearing Clay from the Neighborhood of the Bertha Zinc Mines, Pulaski County, Virginia. Chemical News, 1881, XLIV, 207 ; The Virginias, 1883, IV, 4.
lliggins, Edward, Jr. Zinc Mining and Smelting in Southwestern Vir- ginia. Engineering and Mining Journal 1906, LXXIX, 608-610 ; 658-659.
The New Eiver — Cripple Creek Mineral Begion of Virginia. Harrisburg, Pa., 1887, 18, 24, 40, 61. 54- 58, 70-76, 82, 89.
Stripping Ore Deposits. Transactions American In- stitute of Mining Engineers, XVIII, 627-633.
Zinc Smelting at the Bertha Works, Virginia. Engi- neering and Mining Journal, 1893, LVI, 544.
The Zinc Ores of Virginia. Engineering and Mining Journal, 1904, LXXVII, 544.
The Faber Lead and Zinc Mines. The Virginias, 1885. VI, 47.
A Geological Eeconnaissance of Bland, Giles, Wythe and Portions of Pulaski and Montgomery Counties, Virginia. Proceedings American Philosophical So- ciety, 1887, XXXIV, 61-108.
Watson, Thomas L. Lead and Zinc Deposits of Virginia. Geological Sur- vey of Virginia, Bulletin No. 1, 1905, 156 pages.
Lead and Zinc Deposits of the Virginia-Tennessee Region. Transactions American Institute of Min- ing Engineers, 1906, XXXVI, 681-737.
The Mining, Preparation and Smelting of Virginia Zinc-Ores. Transactions American Institution of Mining Engineers, 1907, XXXVII, 304-318.
McCreath and d^Invilliers.
McDowell, E. H.
Moxham, E. C.
Payne, C. Q.
Seamon, W. H.
Stevenson, J. J.
GOLD AND SILVER. 549
IV. OOLD AND SIL7EB. Historical.
The earliest reference to gold in Virginia, so far met by the author, is by Thomas Jefferson, in 1782, in which he describes a lump of ore weigh- ing about 4 pounds, taken from the north side of the Bappahannock river, about 4 miles below the falls. The lump is reported to have yielded 17 pennyweight of gold. Jefferson heard of no other indications of gold in the neighborhood.
The first discovery of gold in Virginia, after the date of Jefferson^s note referred to above, is reported in 1831. The Virginia Mining Company of New York, operating between the years 1831 and 1834, the Grasty tract of land in Orange county, was the first gold mining company incorporated in Virginia. The date of the incorporation was March 10, 1832. The Orange county, Virginia, deed books show that a one-half interest in a 20-year lease on the 5-acre mining tract, dated 1829, was purchased in 1831 for $30,000 in cash. In 1836 there was considerable activity in gold mining in the State, and the production was reasonably steady from the rediscovery in 1831 to 1850, the annual value being given between $50,000 and $100,000. Increased activity in gold mining in the State was manifested in the early fifties, but the Civil War almost completely stopped mining opera- tions both in Virginia and in the South generally.
The first mint returns from Virginia date from 1829. Considerable activity was again manifested in the Virginia gold fields after the close of the Civil War, and milling and reduction plants were erected at various points. Many of these attempts met with only small success and in most cases they were abandoned, not because of the lack of ore but because, largely, of bad management and inexperienced mining, together with th(» refractoriness of the Virginia ores.
Distribution.
Map, figure 98, shows the location of principal areas in Virginia from which gold has been mined. The principal gold deposits of Virginia are found east of the Blue Ridge and occur in the crystalline rocks of the Piedmont plateau. These are arranged in a belt which begins in Mont- gomery county, Maryland, and extends across Virginia in a southwesterly direction to the North Carolina line. The belt varies in width from 16 to 26 miles and is 200 miles long, covering an area of some 4,000 square miles, with its best developed portion in Fauquier, Stafford, Culpeper,
UINERAL HE80UH0EB OP VtHQlNlA-
GOLD AND SILVER. 561
Orange, Spottsylvania, Louisa, Fluvanna, Goochland, and Buckingham counties. Gold is also found in Appomattox, Prince Edward, Charlotte and Halifax counties, which mark the southwest extension of the principal belt. Excepting Halifax no developments have yet been made in these last named counties. Gold is found in Franklin county between Pig river and Eocky Mount in quartz veins enclosed in micaceous schists. Some alluvial gold has also been noted.
A smaller belt is situated on the west side of the Blue Eidge in Arontgomer}', Floyd, and Grayson counties, but as yet it is undeveloped and has proved of little economic importance. The work in Montgomery county has been mostly in the nature of sluicing and panning.
Many of the mines in the principal belt have produced large quantities of gold, as shown in the United States mint returns tabulated below, and have been rather extensively worked. So far as is known at present very few of the mines are actively producing, although considerable prospecting is in progress and at some, extensive preparations for mining are being made.
The mines in Fauquier, Stafford, Culpeper, Orange, and Spottsylvania counties are grouped about and near the junction of the Eappahannock and Eapidan rivers in a belt about 15 miles wide. This principal belt is crossed by innumerable streams bordered by placers.
Oeneral Oeology.
The couniry-rocl's, — The principal rocks of the Virginia gold bell are micaceous schists and gneisses, often garnet if erous and chloritic, and in places homblendic. They include both altered sediments and igneous masses. The prevailing strike is north 20°-30° east and the dip is toward the east and southeast at varying angles, frequently steep, and in many cases nearly vertical. Granite masses and dikes of basic igneous rocks occur in the region, sometimes sheared from dynamic causes.
The veins, — The gold-bearing veins are quartz, which vary in texture from large crj'stalline masses to very fine saccharoidal grains. In structure they vary from massive to thin platy or schistose bodies, both usually penetrated by closely spaced irregular fractures. The principal metallic content is auriferous pyrite which, at times, is copper-bearing and contains more or less admixed chalcopyrite. Within the weathered zone, which extends from the surface down to local water level and accordingly is variable in depth, the quartz is rendered more or less porous or cellular and discolored or stained with iron-oxide from the oxidation of the
552 KINEEAL RESOUBOSS OF YIBOINIA.
sulphide xninerak, and the liberation of free or elem^taiy gold. d('gree of porosity and staining is proportional to the amonnt of sulphide minerals present and the stage of oxidation. Below the water level the veins are fresh, the sulphides are unaltered, and d gold is less frequent in occurrence.
From the general descriptions of the mines given below, it wilF observed that the principal and early operations were confined to the oxidized portions of the veins, which yielded a free miUing that was easy of treatment. Since then operations include the mming sulphurets or the sulphide bodies, which require a different metall treatment of the ores, in order to extract and recover the gold. The occurs both as free milling ore within the weathered zone and as phurets below the local ground water-level.
The auriferous quarts veins conform in the main to the strike and dip, of the enclosing rocks; a fact which has caused explanations to be advanced by differ^! observers. They were roga by some as contemporaneous with tt^l^^Qfteations in which they occur; others as true veins of injection, andiionnad subsequent to the schis of the enclosing rocks ;^:by still . othetlB as beds; and lastly by some veins of segregation. * As pbinted out )3g|r Prof essor W. B. Bogers, in that although in the.iiuiin'-the dio.ia^d^^trike.bf the veins confcmn those of the enclosing rOcks, the oAMipbndence is far from being for they frequently cut the scbli^ at small angles both in dip and s' This evidence is sufficient to establish the fact that the formation of the veins post-dates the schistose structure of the enclosing rocks.
The vein structure is irregular lenticular, varying in width frrm • few inches to as many feet. Often the lenticular stringers are dipcontinuoa& One stringer may dwindle to a thread or disappear and is replaced Ijf another or by others. Some of the veins are remarkable for their pe^ sistcncc and continuity, conditions best illustrated perhaps by the Fishe* Jj lode in Tjouisa county, which has been opened along the strike for t J (listanro of some 5 miles and to a maximum depth of 250 feet, by at leeafc . 5 mines.
The gangue minerals. — ^Excepting quartz and pyrite, the gangue minerals in the gold veins of Virginia comprise the following species: ■ Chalcopyrito, native copper, galena, mispickel (arsenopyrite), pyromorphits» tetrahedrite, tourmaline, vanadinite, sphalerite, pyrrhotite, and sideritei - According to S. F. Emmons the telluride of bismuth, tetradymite, is found \ in several of tho Virginia gold mines. So far as the gangue minerals
\
4 1
THE NEW YORK
PU I? JJC LIBRARY
A:-TCh, LENOX AND TlLDtN FOUNDikT'OHIb
GOLD AND SILVER. 653
concerned the Virginia gold ores are entirely typical in character. The ores are quartzose deposits in which pyrite is usually present, chalcopyritc common, galena, mispickel, and sphalerite are not rare.
DESCEIPTION OF KINES.
Fauquier County.
Map, plate LXXX, shows the location of the known mines in the principal gold belt of Virginia. The mine description which follows below by counties amounts, in most cases, to hardly more than the naming and location of the known gold mines in the State. This is made necessarj' l>ecause of the fact that a majority of the openings are of very long stand- ing, and are at present in such condition that the geological relations are practically obscured.
The gold mines are located in the southern part of Fauquier county, near Morrisville, about 8 miles southeast of Bealeton, a station on the main line of the Southern Railway. The principal mines are the WyJcoff, Kelly, Bancroft, Franlclin, and Kirk. Of these,- the Franklin mine was the most extensively worked and ' comprised a 20-stamp mill. An average of 10 assays of samples of ore taken from this mine gave a reported gold value of $24.24 per ton. In 1901 and 1902 about 1,000 tons of tailings were leported cyanided from this liiine, but d satisfactory extraction was difficult, presumably, because of 1»e f>Fe8ence of selenium. According to Lindgren, the deposit is a strong fisBure in. diorite, accompanied by an intrusion of diabase, and was worked to a depth of 80 feet for a continuous length of 700 feet. The Kelly and the Kirk mines both operated 10-stamp mills.
Stowe described 3 veins at the Wykoff mine, one of which, known as the "Mill-House," is given as 20 feet thick. The assay values of the 3 veins are given as follows: "Mill-House," $41.28 per ton; "Tunnel" vein, same value as the "Mill-House"; "Slate" vein, $89.19 per ton. An assay of a sample of ore taken from still another outcrop gave $30.00 per ton. None of the Fauquier county mines were operating in the summer of 1906. The Kelly mine is reported to have been the one most recently worked. The Virginia Mining and Development Company is working the Liepold mine. Preparatory to opening the mine, a 10-stamp amalgamation mill vas worked on the property.
Stafford County.
The principal mines are located in the western part of the county near the Rappahannock river. The Eagle mine, located 12 miles north- west of Fredericksburg, was extensively worked until 1894 by the Rappa-
554 MINERAL RESOURCES OF VIRGINIA.
hannock Gold Mining Company. Its length of workings is 600 feet and its greatest depth is 250 feet. The Monroe, Lee, and Rattlesnake mines are in the same vicinity; the Monroe and Rattlesnake mines adjoin the Eagle on the northwest. The Rattlesnake mine was worked as a placer and lerge quantities of nuggets are reported to have been taken from it, which weighed from one-half to 5 dwts., and some ranging as high as 125 dwts. The Rappahannock mine, 14 miles northwest of Fredericksburg, is situated in the Hartford district, near the Rappahannock river, and was operated both before and after the Civil War. This mine was worked t^ a depth of more than 200 feet.
Culpeper County.
The Culpeper mine is located on the Rapidan river, 18 miles west of Fredericksburg. In a report made by Professor Silliman in 1836 it is stated that the average value of this ore was $25.00 per ton. Other mines in the district are the Richardville and Ellis. The Powhatan Land and Mining Company operated a mine in Culpeper county in 1894, treating the ore in Crawford mills and a 10-stamp mill in connection with Fme vanners.
Spottsylvania County.
The oldest mines worked in this county were those operated by the United States Alining Company, located near the Rappahannock river, in the extreme northwest corner of the county. A 2-foot vein was operated by adits and shaft?, tlie deepest of which was 80 feet. The value of the ore mined was roporfed to have been $25.00 per ton and the cost of milling 80 cents per ton.
The following description of some of the earlier milling methods, as practised at the mine near the Rappahannock river, is taken from a report of the Supervising Committee of the United States Mining Company in 1835, as quoted by Nitzc and Wilkens in Bulletin No. X of the North ('arolina Geohxjuvl Survey: "The plant consists of a crushing (rolls) and a vertical mill (stamping-mill) in a building 26x36 feet. Both mill^ are located on the ground floor and are propelled by a water-wheel 11 feot in diameter, with a 11-foot face. The crushing-mill has 3 sets of cylinders 2 feet in length and 15 inches in diameter, the first or upper set fluted, the other smooth. The ore is thrown into a hopper on the upper floor, from which it is conducted over an inclined shaking-table to the tinted cylinders by which it is crushed to a size from ^4 ^^ 1 inch in dianuli r. The crushed material is equally divided and goes to the two
EXPLANATION OF PLATK LXXXI
S
•i ''E^
•p g _ V cc ^ .5 o j3 a
= «*-*, .5
GOLD AND SILVER. 565
sets of smooth cylinders. By them it is further greatly reduced, ranging from impalpable powder to grains as large as coarse hominy. From these cylinders it falls into a sifter having the fineness and motion of the common meal-sifter, from whence the material which passes through is con- ducted to 12 amalgamators, constructed upon the principle of the Tyrolese bowls, making from 90 to 100 revolutions per minute. They perform the office of washing and amalgamating. The sand discarded by them, after being washed, is conducted through troughs to the vertical mill, where, being reduced to an impalpable powder, it passes in the shape of turbid or muddy water to another set of amalgamators similar to those above- mentioned, and thence to the river. The portion of the ore reduced by the cylinders which pass over the sifters is conducted to the vertical mill, and is treated in the same manner."
West of the central portion of the county is a group of mines among which the Whitehall is the most prominent. Gold was first found at the Whitehall mine in 1806, and it was worked from 1848 until just before the Civil War and subsequently as late as 1884. Returns from the Philadel- phia mint show that this mine produced $1,800,000 in gold from the be- ginning of operations down to 1881. At a depth of 28 feet a pocket 3 feet square is reported to have yielded $160,000 of .gold. Some of the ore from the shaft of the Chicago-Virginia mitie assayed $30.00 per ton in gold. An average assay value of 12 samples was $14.00 per ton. Prior to 1880 considerable placer work was done. Other properties in this group are the Higgins, Johnston, Pulliam, and Grindstone Hill mines.
Farther south on Pigeon Run are located the Mitchell and the Good- wyn mines. In the earlier days considerable placer work was done along Pigeon Run. The placer workings of the Pocahontas Gold Mining Com- pany at Andrews in the south central part of the county comprised 150 acres in the eighties.
Orange County.
The gold mines of Orange county are located in the northeast corner of the county, near the Rapidan river, and along and north of the narrow- gauge railroad, operated between Fredericksburg and Orange. The first gold mining company incorporated in Virginia was the Virginia Mining Company of New York, operating between the years 1831 and 1834 on the Grasty tract, near St. Just post-office in Orange county.
The Vavclvse mine, discovered and opened in 1832, is the most promi- nent one among the mines of Orange county. In 1843 its plant was valued at $70,000. A description of the milling practice at this mine in
556 MINERAL RESOURCES OF VIRGINIA.
1847 is quoted from Bulletin No. X of the North Carolina Oeological a^lurvey : "The machinery consists of a condensing Cornish mining engine of 120 horse-power; the mill-house contains 6 large Chilean mills; the cast-iron bed-plate of each is 5 feet 6 inches in diameter, and on it are two cast-iron runners of the same diameter, the total weight of the mill being 6200 pounds. The ores, on arriving at the surface, are divided into two classes : 1. The coarse and hard ore for the stamps; 2. Slate and fine ore for the Chilean mills. This is done by means of a large screen. The very large pieces are first broken by a hammer before they are fed to the stamps. All of "the ores are ground with water, each mill being supplied with hot and cold water at pleasure. Twelve inches from the top of Ihe bed-plate there is a wide, open mouth, from which the turbid water escapes to tanks. On the south side of the steam engine is the stamp liouse and amalgamation mill, containing 6 batteries of 3 stamps each; these stamps, with the iron head of 125 poimds, weigh 350 to 380 pound? each. Each battery is supplied with water, and at each blow of the stamp a portion of the fine ore passes out of the boxes through the grates to the amalgamation room. Here are stationed 18 small amalgamation bowls c»f cast iron, 30 inches in diameter. The bowls are supplied with runners which move horizontally; in the center of these runners is an eye or opening like that in the runner of a corn-mill. The ground or finely- stamped ore, gold and water pass into this eye, and by the rotary motion c»f the same are brought into contact with the quick-silver deposited in the center, forming amalgam. From the amalgamators the pulp passes through 3 dolly-tubs or catch-alls, acting as mercury and gold tubs. After this the whole mass passes to the strakes or inclined planes, where the sulphiirets are deposited and the earthy matter washed away. These sulpluirt'ts were formerly treated in two heavy Mexican drags or arrastras; but not answering so good a purpose, they have been altered into three heavy Chilean mills."
A 14-foot vein at the 60-foot level was reported in 1880 at the Chicago- Virginia mine at Mine l?un. Other mines in the vicinity are the Randolph, Oranfje Grove, Grornwood, Melville, and the Orasty.
The Pied rn out Mining and Metallurgical Corporation of Philadelphia, Pennsylvania, incorporated under the laws of Virginia, recently obtained 930 aercs of the desirable gold-bearing lands, stretching northward from St. Just post-oflice, near Clark^s Mountain and about 8 or 10 miles west of the Vauclvsr mine, in Orange county. Several of the tracts included in tliis property were extensively worked and were large producers in the <arly flays of gold-mining in Virginia. One of these, the Orasty tract, was
IflN'KIUI. ItRSOIRrRS OF
PLATE LXXXII.
l;. I.^K\]iii^uic' i r hir;;!' i;iilil- niiil i'i>]i]»'r-l)i-jirinj: vi'ins ii«ir the iiorthcrn j>iirl uf (Iw '■Aimiiiiiii Tnii't,"' cm l,uil;;i' Xo. 1. iihoiit ',i *"'!* """th of Ihe '■X<>rth-Ka>l"' -liiift. Chiuiiii'v of tlic olii Virj.'iniii Mining Com- i»iiiv's mill. IniJIl. in IH:t2. ^iKmii' in t\«- l>ii.-k;-ri»iiiil. ()niii|.«? <-<nintv. iTIiV' I'ifKliMoil Miiiint' niul MtMi<lliir}!i<-ol t '..r|->r:ili<>ii,l
ll
,1
Ij
I
GOLD AND SILVER. 557
the first gold mine incorporated in Virginia. Five different mining com- panies formerly operated on 3 of the tracts now owned by the above corporation. These were: The Virginia Mining Company of New York, operating between the years 1831 and 1843; the Chancellorsville-Freehold Oold Mining Company of London, England, operating between the years 1853 and 1857; the Chicago-Virginia Oold Mining Company, operating between the years 1879 and 1881 ; the American Oold Mining Company, operating between the years 1881 and 1883; and the Oold Run Mining Company of New York, which sank the shaft north of the branch on Mine Eun. The mining work done by these companies comprised a total of 578 feet of shaft-sinking, 11 shafts of which were on the Orasty tract, 3 on the Chicago-Virginia tract, and 1 on the Dickey tract; more than 1.000 feet of drifting on the veins; and about 400 feet of undergroimd cross-cutting, tunnelling and surface open-cut work, the largest part of which was on the Orasty tract. This work proved all the veins to be gold-bearing, of good width, and carried good ore values.
It is reported that the above mining companies mined several thousand tons of ore during the time of their operations, which embraced several periods of workings between 26 to 75 years ago. The reported gold values of the ore mined varied from $6.00 to $32.00 per ton. Recent develop- ment work on these properties, to a depth of 40 feet, by the Piedmont Mining and Metallurgical Corporation, show gold values made on many tons shipped to reduction works ranging from $4.13 to $201.67. Sorted ores gave assay values as high as- $41.34, while concentrated ores ran as high as $103.00. The estimated probable cost of mining and milling these ores will not exceed $2.25 per ton, in a 100-ton per day plant.
Louisa County.
The gold-bearing rocks of Louisa traverse the central portion of the county, in a southwesterly direction, in the form of a narrow but well- defined belt. Near the center of the county and in the gold belt, 2 to 5 miles northeast of Mineral, are the famous Louisa county pyrite mines described on pages 198-202 of this volume. These large bodies of pyrite are probably contemporaneous in origin with the gold veins. The ore lenses of pyrite and the quartz veins carrying gold observe similar strike, dip and pitch. Traces of gold are found in the pyrite and small gold- bearing quartz veins which, according to W. H. Adams, formerly manager of the Arminius mines, are gold-bearing to the extent of from $4.00 to $16.00 per ton, are reported encountered in the mines on the hanging- and foot-wall rocks.
558 MINERAL RESOURCES OF VIRGINIA.
The Tinder Flat placer deposits, located along and on both sides of >^orth Contrary creek, at the north end of the pyrite mines, were perhaps the best known and most productive source of placer gold in the early days of Virginia gold-mining. These placer bottoms were tested again in 1895 with a view to putting in the necessary modern machinery for working them on a large scale. The silver content of the Allah Cooper mine, 2 miles northeast of the Tinder Flats, is reported to have been un- usually large. A half-mile southwest of the Arminius pyrite mine and on the same line of strike is the Walton gold mine. According to Nitze and Wilkens this mine produced some very rich ore from a shoot or chimney developed to a depth of 150 feet. No recent mining has been done as the mine has been tied up for many years in litigation.
The Walton mine is located south 10** west about half a mile from the Arminius p3rrite mine. Considerable pit prospecting has been done on the property and one shaft has been worked to a depth of 150 feet. The country rock is mica schist of the same character as that enclosing the pyrite lenses at the Arminius pyTite mines. This mine has not been operated for some years, but during the period of its operation, its is reliably I'eported to have been one of the best producers in the area. A most creditable exhibit of the ores from this mine was made at the Philadelphia Centennial.
The Cooper mine, located about a quarter of a mile south 10** west of the Arminius pyrite mines, is developed by a principal shaft about 100 feet deep sunk on an incline of 56° south 80° east. The property has been further prespected quite extensively by numerous open pits. The country- rock is the same as that at the Arminius pyrite mines. It contains thin Quartz stringers which in turn contain some admixed calcite with pyrite, and a little chaloopyrite. Work was suspended here in 1903.
The Lvce gold mine is located about one mile south 25° east of Mineral end about a quarter of a mile south of the Chesapeake and Ohio Eailway. The coiintr}-rock is a crinkled mica schist containing some garnets. The property has been developed by 2 shafts about 300 feet apart and aligned along a north 30° east direction. These shafts dip 60° and 70° nearly southeast. Nimierous smaller openings are made over all parts of the property. A 20-stainp mill was operated at this mine, but from neglect it is rapidly going to wreck and ruin. Indications point to a period of considerable activity at this mine some years back. Much ore was mined and milled. It was probably the most extensive gold operation in the district.
GOLD AND SILVER. 559
The Chick mine, situated about 1.5 miles east of Mineral, is a recent development in the district. At the time of my visit in July, 1906, opera- tions had been suspended and the development work comprised an open cut and tunnel about 50 feet long and 10 to 15 feet wide. This opening is made in a gametiferous mica schist, the schistosity of which strikes north 15** east and dips nearly vertical. The vein where exposed consisted of thin stringers of quartz interleaved with the schist, the thickest one of which did not exceed 4 feet. A 2-stamp mill had been built and the total pro- duction was $65.00.
Two miles east of and parallel to the pyrite ore-bodies, and about one mile east of Mineral, the veins known as the Fisher lode have been opened and developed by the Harris, Luce, Slate Hill, Louisa, and Warren Hiil mines. The Luce and Slate Hill mines were operated as late as 1895. Thi? I/uce mine was developed to a depth of 200 feet with the total lenglh of drifting on the vein more than 1,000 feet. Width of the vein is from 3 to 8 feet. A 20-stamp hand-feed mill was operated at the mines. The Slate Hill mine was first opened in 1850 and was extensively worked for a while. It joins the Lu^e mine on the southwest, of which it formed a part. Two veins were developed to a depth of 150 feet. According to a report made in 1853 the average value of the ore is given at $4.00 per ton and the cost of mining and milling at $1.40 per ton. In 1895, a Huntington mill had been erected and the mine was being developed in the lower levels.
Fluvanna and Ooocliland Counties.
The gold belt traverses the boundary of Fluvanna and Goochland counties, crossing the James river at Bremo Bluffs into Buckingham county. Some of the mines in this belt are located partly in both counties, and for this reason the two counties are treated together. Among the principal properties are the Tellurium, Bowles, Payne, Page, Hughes, Moss, Fisher, Bushy, Taugus, Gilmore, Collins, Snead, Marks, Fades, Bertha and Edith, Waiters, Manning, Big Bird, and the Behora. From 1830 to 1860 this belt was extensively operated but at present the district is comparatively quiet and but little work is in progress.
The Tellwrium mine, located 6 miles from Columbia, lies partly in Fluvanna and partly in Goochland counties. It was discovered in 1832 and was continuously worked until 1857. It was operated again as late as 1886 and during its several periods of activity is reported to have yielded $1,000,000.00 Three gold-bearing veins, the "Big Sandstone," "Middle," and 'Tjittle," trending northeast-southwest and dipping 20° to 30** east have
560 MINERAL RESOURCES OF VIRGINIA.
been traced for a distance of more than a half mile. It is reported that the average value of the ores mined from the ^Tiittle** and "Middle" veins during the 14 years was $100.00 per ton, the minimum being $6.00 and the maximum $300.00 per ton. The value of the ore mined from the '^ig Sandstone" vein during the 9 years of operating is estimated at $20 per ton. This vein was developed by numerous shafts, the deepest one of which is reported to have been 120 feet. A 10-stamp mill was operated at the mine.
The Bowles mine adjoins the Tellurium. Lying partly in Fluvanna and partly in Goochland county, within a half mile of the Tellurium and Bowles mines are the Fisher, Moss, and Busby mines, all on the same lode. In 1882. the Bertha and Edith mine was worked chiefly as a placer deposit. The Snead mine, located 2 miles north of Fork Union, Fluvanna county, has not been worked for 20 years.
The Fisher mine was opened in 1860 and in 1896 had been developed by a 40-foot shaft and 176 feet of levels. The vein varies from 3 to 15 inches in width but carries reported values of from $26 to $300.00 per ton. One mile northeast of the Fisher is the Moss mine, which was dis- covered in 1835. It was worked to a depth of 65 feet and the vein, which according to Nitze and Wilkens is 2 feet in places, carries values from $15.00 to $65.00 per ton. This mine is located 2 miles west of Caledonia, Goochland county, and is leased by the Telluric Gold Mining Company. Recent developments at this mine have been very encouraging.
Two veins traverse the Moss property for a distance of about 2,500 feet along the strike. One of the veins is described as composed of lentic- ular masses of highly laminated quartz enclosed by micaceous schists and (lipping about 45° southeast. The ore is practically free-milling down to a depth of 130 feet on the dip, when the sulphides appear. Recent sampling of the workings is reported to have given an average value of $16.00 per ton. Recent developments comprise 2 shafts, one of which is 118 feet deep on a 55° dip, with a total of 285 feet of drifts in ore milling $15.00 ]>er ton. A small shoot was cut in the west level which averaged about $150.00 per ton of gold and 40 ounces of silver. The second shaft is down 130 feet with 60 feet of drifts in ore yielding $14.40 per ton. A milling plant is in operation.
Work at the Bushy mine a half mile northeast of the Moss has been of a superficial nature. According to an early report by Professor Silliman this ore gave values of $160.00 per ton. The Page mine is located a half mile west of Wilmington on Long Island creek in Fluvanna county.
UtKBRAL RBSOUKCRS OF VIHGIXIA. PLATE LXXXlll.
GOLD MILLING PLANT ASD OPEN GUT, ViaGlSli..
Figure 1.— General view of the Hughes Qold Mining and l^lHwg Ooni|Nuij*i plaati near Foric Union, Fluvanna county, Virginia.
Figure 2. — Open cut a few feet south of the old Viiginia iflnfag CSom|MnT's miB shaft The gold-bearing quartz ledge No. 1 is uiowii at the lear end of the open cut. The Piedmont Mining and Metallurgical Gorpormtloiiy Oraqge eovBtj, Virginia.
UlNERAL nESOUncBS OF VIUQINlA
PLATE LXXXllI.
GOLD MILLING PLANT AND OPES C\3T, Nl^JOVS^^..
GOLD AND SILVEB. 561
Mining of the quartz vein was begun in 1856 and an 8-stamp mill was built. Considerable prospecting work was reported in progress prior to 1895.
The Hughes mine, owned and operated by the Hughes Gold Mining and Milling Company, comprises a tract of 275 acres, located 5 miles north of Bremo, a station on the Chesapeake and Ohio Railway. This mine was first opened in 1836. Operations conducted by the Hughes Gold Mining and Milling Company for the past several years have been very encouraging.
The developments comprise shafts, drifts and open-pit work. Shaft No. 1 is sunk to a depth of 40 feet on the large ore-body. A level is driven southwest for a distance of 140 feet from the bottom of the shaft and more than 50 feet of ore have been stoped and milled above this level. Test-pits sunk to the northeast of the shaft have proved the vein for a distance of 1,500 feet, with a thickness of from 1 to 5 feet. According to the general manager, Mr. William Bugbee, a mill run on 585 tons of ore stoped from this vein gave a gross value of $9.00 per ton of gold.
Shaft No. 2 is sunk on a second vein 800 feet southwest of the former one to a depth of 110 feet. Two levels at depths of 60 and 110 feet, respectively, are driven from this shaft. The ore-body stoped out from the surface to the first level, 60 feet, varied from 1 to 3 feet in width and showed an average value of $20.00 per ton. Some favored spots are reported to have averaged as high as $711.00 per ton. This ore-body has been opened for a distance of about 230 feet and shows an average thick- ness of 2 feet, varying between 1 and 4 feet. The average value of the ore is given at $13.00 per ton of gold, based on most careful sampling and assa3dng.
In addition to these, pits have been sunk on 4 other gold-bearing leads, 3 of which are from 2 to 3 feet thick and assay at or near the surface about $5.00 in gold per ton. The fourth is a 15-inch vein which assays $23.00 per ton of gold at a depth of 18 feet.
The milling plant, comprising stamp mill, concentrating, cyaniding, and furnace departments, is commodious and modem in all respects. The 3 following facts have been demonstrated by Mr. Bugbee: (1) That more than 90 per cent, of the gold in the ore can be saved. (2) That the ore will average nearly $11.00 per ton of gold. (3) That the total cost of mining and treating the ore is a fraction over $4.00 per ton based on the present capacity of the plant.
The Belzora mine, discovered in 1832, is located 7 miles from Columbia, in Goochland county. It was worked by surface washings until 1849, after
562 MINEBAL RESOURCES OF VIROINIA.
which time the veins were opened. Adjoining the Belzora are the Maria, Collins, Fades and Big Bird mines.
Buckingham County.
Buckingham is the most southwesterly county of the Virginia gold belt in which mines have been actively worked. As stated above, the occurrence of gold is known still farther to the southwest in Appomattox, Prince Edward, Charlotte, and Halifax coimties but, as yet, no developments hare been made, except in the last named county, Halifax.
The principal mines operated in Buckingham county were the Booker, sometimes called the Morrow; London and Virginia, Buckingham, Oamei end Mosely, Morton, Ford, Philadelphia, Willis CreeJc, Piedmont, Apper- son, Duncan, Anaconda, and the Lightfoot. All of these were actively worked at one time. The largest ones were operated extensively before the Civil War and are reported to have produced large amounts of gold. Some of these have been worked since the War and a few within recent years.
The Booker mine is located 4 miles southwest of Dillwyn and was extensively worked prior to the Civil War by an English Company. The mine is developed by numerous shafts and drifts, the deepest of which is 106 feet. The work is of such long standing and the dumps so entirely cleaned up that very little could be seen at the time of my visit in August It is reported that the ore was treated in a Howland mill and yielded $13.00 per ton.
The London and Virginia, and the Buckingham mines join each other and the oponings extend from one on to the other, along a north 40** east direction. These mines are located one mile northwest of Dillwyn. They were developed by shafts and open-cuts, the deepest of which will not exceed 160 feet. The principal opening is a cut which extends nearly entirely across both properties. It is variable in both width and depth, with a probable average of about 12 feet wide and from 20 to 80 feet deep. It follows the dip and strike of the vein which closely conforms with the structure of the enclosing mica-schists. The schists vary from biotite-muscovite to sericite and finely laminated quartzose rocks. These properties were large producers before the Civil War, but at the beginning of the War they were closed down and practically no work has been done since. Some placer gold was mined in the early days in the vicinity on Turpin's creek.
At the Anaconda mine, three-quarters of a mile southwest of Johnston,
GOLD AND 8ILVEB. 563
development work on a small scale was in progress in Augnst, 1906^ by the Anaconda Gk)ld Mining Company. This property was worked as a placer deposit some years ago.
The Lightfoot mine, situated 2 miles northwest of Arvonia, on the east side of the Slate river, was worked in 1861 and again developed by an 86- foot shaft and drifts some 5 or more years ago for copper. Preparations are now in progress for the further development of this mine.
The Apperson mine, 12 miles southwest of New Canton and 10 miles northeast of Buckingham court-house, comprises 3 veins, one of which measured 10 to 15 feet wide of gold-bearing rock.
Halifax County.
In the Virgilina copper belt of Halifax county, gold-mining is engaged in and 2 mines have been opened up, situated close together, about 6 miles directly north of the town of Virgilina. One of these, the Ooldbahk mine, incorporated under the name of the Virgilina Oold Mining Company, is an active producer of gold at the present time.
The vein is parallel and similar to the numerous other veins in the district worked for copper, except that besides a little copper its chief value is in gold. The vein material is quartz enclosed by highly altered andesite, resembling somewhat a sedimentary slate. It is nearly vertical, and has a nearly due north-south strike. The elementary gold is very finely divided and is contained in both the quartz-filling and the enclosing country-rock. Sulphides of copper occur in subordinate amount but no attempt is made to save them. The value of the vein is said to average $8.00 per ton of gold across it^ width of 6 feet.
A vertical shaft has been sunk to a depth of 160 feet and drifts have been run along the vein at this level for a distance of 100 feet to the north and 300 feet to the south, taking out the entire width of the vein. A mill containing 2 batteries of 5 stamps each is operated at the mine. Two more batteries are contemplated. The stamps weigh 750 pounds each. No attempt is made to save or treat the tailings which are known to be rich in gold. During 1906 about 10 tons of ore per day were being milled.
The Howard gold mine, located only several himdred yards from the Ooldbank mine of the Virgilina Mining Company, has temporarily sus- pended operations. A milling plant has been built at the mine carrying a battery of 5 stamps. The underground developments comprise some c»haft and drift work.
564 MINERAL RB80UR0E8 OF VIBOINIA.
Hontgomery and Floyd Counties.
On the west side of the Blue Bidge and at the southeast base of Pilot Mountain, placer deposits were opened in 1879 along Brush and Laurel creeks, in Montgomery and Floyd counties. Most of the tributaries to Brush and Laurel creeks show some gold and prospecting has extended over an area 20 miles wide by 4 miles long, a total of 80 square miles. The area is further traversed by numerous white and mottled gold-bearing quartz veins.
According to Professor Fontaine, the average yield for the best of the earth in 1882 was about 5.5 grains of gold per pan of 25 pounds of earth. The gold contains about 32 per cent, of silver. The quartz veins and stringers charged with pyrite are in gneiss and specimens of the vein and of the gneiss were sampled by Professor Fontaine and separately assayed with the following results:
Veins 64.6 grains per ton of which 27.1 grains were silver.
Gneiss 6.7 grains per ton of gold and silver.
Gneiss 6.4 grains per ton of gold and silver.
In 1880, $2,500 worth of gold is reported panned out in 2.5 months. One assay is stated to have yielded $94.00 per ton of gold and $3.00 of silver. Nuggets were taken from the loose deposits that sold for $2.00 and more a piece. An analysis made by Mr. Porcher of a specimen of native gold from the workings in Montgomery county gave :
Per cent.
Gold (by cupellation and parting) 65.31
Silver (by cupellation and difference) 34.01
Copper 0.14
Iron 0.20
Quartz 0.34
Total 100.00
Specific gravity 15.46
Gold occurs in Patrick, Carroll, and Grayson counties in small quan- tity in association mostly with copper ores.
Production.
Records of actual production from mining operations in Virginia date from 1829. The XJ. S. Mint returns from 1829 to 1854 show that nearly one and a half millions of gold were deposited during that period from Virginia mines. The following tables are compiled from the produc- tion reports of the XJ. S. Mint. The figures represent not only the amounts
GOLD AND 8ILVEB.
565
deposited at the XT. S. Mint and Assay Offices but such other amounts as were produced and not turned into the Mint of which records could be obtained:
Production of gold and silver in Virginia by years.
Year Value
1799-1879... $3,091,700
1880. 1881. 1882. 1883. 1884. 1885, 1886. 1887. 1888. 1889. 1890. 1891. 1892.
11,500
10,000
15,000
7,000
2,500
3,500
4,000
14,600
7,500
4,113
6,496
6,699
5,002
Year Value
1893 $ 6,190
1894 7,643
1895 6,325
1896 4,466
1897 not given
1898 4,500
1899 7,160
1900 3,200
1901 6,720
1902 6,227
1903 18,630
1904 7,686
1905 5,122
The following results show the U. S. Mint returns for the first 6 years of production of gold in Virginia, from 1829 to 1833, inclusive :
Year Value
1829 $ 2,600
1830 24,000
1831 26,000
1832 34,000
1833 104,000
The following table shows the distribution of gold and silver in Vir- ginia, annually, as to sources of production, from 1900 to 1906, inclusive:
Gold
Silver
|
Year |
Quartz Fine ounces |
Placer Fine ounces |
Quartz Fine ounces |
Copper ores Fine ounces |
|
1900 1901 1902 1903 1904 1905 |
78 185 181 216 202 |
94 128 27 — 39 |
96 617 173 |
|
|
427 1,344 17,073 |
||||
In 1904, the production of gold and silver in Virginia was contributed to by eleven counties. From the XJ. S. Mint returns for 1906, Lindgren estimates that for Virginia, gold increased in value over 1904, $1,182 ; and silver decreased $3,779. In 1905, 7 mines were reported producing, 3 of which were placer mines. According to Lindgren the 4 deep mines yielded an estimated tonnage of 800, giving an average of $5.36 per ton in gold and sflver.
566
MINERAL RESOURCES OF VIRGINIA.
Becker, G. F.
Campbell, J. L.
Credner, H.
Delrio, A.
Emmons, S. P.
Hotchkiss, Jed.
Johnson, W. R.
Judd, Edward K.
l^ocke, A. G. Maury, M. F.
Morton, J. H.
Xitze, H. B. C.
References.
A Reconnaissance of the Gold Fields of the Southern Appalachians. 16th Annual Report, U. S. Geologi- cal Survey, 1894-6, Part III, 251-331.
The Montgomery County, Virginia, Gold Fields. The Virginias 1880, I, 127.
The Virginia Gold Belt, near the Richmond and Alleghany Railway. The Virginias, 1882, III, 120-121.
On the Gold Mines of Virginia. American Journal of Mining, 1867-69, VI.
Transactions Geological Society of Pennsylvania, 1834, I, 59-166.
Notes on the Gold Deposits of Montgomery County, Maryland. Transactions American Institute of Mining Engineers, 1890, XVIII, 391-412.
The Gold Regions of the Atlantic States. The Vir- ginias 1880, I, 136.
Tellurium Gold Mine, and Virginia Gold Mining. The Virginias, 1881, II, 85.
Some Observations on the (Jold Formations of Mary- land, Virginia and North Carolina. Proceedings American Association for Advancement of Science, 1850, IV, 20-21.
A Virginia Gold Mine. Engineering and Mining Journal, 1907, LXXXIII, 342.
Gold, Its Occurrence and Extraction, 1882, 182.
Notice of the Gold Veins of the United States Mine, near Fredericksburg, Virginia. American Journal of Science, 1837, XXXII, 183-185, 325-330.
The Gold Mines of Fauquier County, Virginia. Engi- neering and Mining Journal, 1877, XXIV, 345.
Gold Mines in Virginia. Engineering and Mining Journal, 1878, XXV.
The Present Condition of Gold Mining in the Southern Appalachian States. Transactions American Insti- tute of Mining Engineers, 1896, XXV, 661-797, 1021-1025.
GOLD AND SILVER.
567
Porcher, S.
Spilsbury, E. G.
Tajflor, J. W.
Silliman, B.
Nitze, H. B. C. and Hanna, G. B. Gold Deposits of North Carolina. North
Carolina Geological Survey, Bulletin No. Ill, 1896, 16, 17.
Nitze, H. B. C. and Wilkens, H. A. J. Gold Mining in North Carolina,.
and Adjacent South Appalachian Regions. North Carolina Geological Survey, Bulletin No. X, 1897, 13-14, 26, 40-42, 71-76, 32 et seq.
On an Interesting Specimen of Native (Jold from Montgomery County, Virginia. The Virginias, 1882, III, 3.
Notes on the General Treatment of the Southern Gold Ores, and Experiments in Matting Iron Sulphides. Transactions American Institute of Mining Engi* neers, XV, 767.
The Gold and Silver Mines East of the Eocky Mount- ains. American Journal of Mining, 1867, II, 390;. Mineral Besources of the United States, 1867, 323- 350.
Remarks on Some Gold Mines, and on Parts of the Gold Region of Virginia, Founded on Personal Observations Made in the Months of August and September, 1836. American Journal of Science, 1837, XXXII, 98-130.
Culpeper Gold Mine, Virginia. American Journal of Science, 1837, XXXII, 185.
T\Tiitney, J. D. Metallic Wealth of the United States, 1854.
See also reports on Precious Metals issued by the Director of the Mint;: Tenth Census, Precious Metals, XIII ; the Mineral Resources of the United States ; the Mineral Industry ; and Census Report on Mines and Quarries- in 1902.
V. TIN.
Mineralog^cal and Chemical Character.
The tin-bearing mineral, cassiterite, is an oxide corresponding to the foimula SnOj and contains theoretically 78.6 per cent, of metallic tin. When pure, cassiterite is nearly white, but it usually contains more or less ferric oxide which imparts a reddish to brown or black color, pro- portionate to the percentage of iron present. The mineral sometimes occurs in prismatic crystals of Tetragonal form, though when found ixk commercial quantity it is more often granular and in rough masses. Three varieties of the mineral are recognized: (1) ordinary or tin-stone-
568 MINERAL BESOURCES OF VIRGINIA.
obtained directly from the vein; (2) wood-tin having the color and ap- pearance of dried wood and of botryoidal and renifonn shapes; and (3) stream-tin found along stream courses in the loose sand and gravel deposits.
Historical.
The existence of tin ore on Irish creek, in Rockbridge county, was known for a long time prior to the first prospecting in 1883, when active operations were begun. The tin ore from this locality was first tested by Professor Armstrong of Washington College, Lexington, in 1846; he claimed that the specimen contained both tin and silver. Only two openings had been made prior to 1883. Since that time prospecting for tin ore has been reported along the eastern edge of Rockbridge county, extending parallel to the Blue Ridge, from a few miles north of the James river into Nelson county. Thus far the most favorable portion of the region in which tin has been found is that known as the Irish creek area, located in the northeastern comer of Rockbridge county, in the crystalline rocks of the Blue Ridge, about 7 miles distant from Vesuvius, a station on the Shenandoah division of the Norfolk and Western Railway, and at an average elevation of about 2,800 feet. A company known as the Virginia Tin Mining and Manufacturing Company was organized in 1883 for the pur- pose of working the tin deposits along the headwaters of Irish creek. The work of sinking a shaft commenced in November, 1884.
Occurrence.
The Irish creek area is about 4 miles long in a northeast-southwest direction and is 3 miles wide, embracing a total area of 12 square miles. The immediate rocks of the area are crystallines, of granitic composition, composed principally of a coarse aggregate of quartz and feldspar (ortho- clase and acid-plagioclase, albite), with hornblende. The rock is porphyritic ill places, the large feldspar crystals measuring as much as an inch and more in length. The coarse granite enclosing the tin veins is reported to be often rich in tourmaline. The granitic rock is generally much decayed at the surface to a mottled clayey mass which is as much as 50 feet thick. A finer textured facies of the granitic rock is quite common. Further variation is shown in lenticular masses of a flesh-colored granitoid facies of the rock, consisting of orthoclase, quartz and epidote, which closely resembles unakite and has been so designated by some.
Dikes of fine-grained altered diabase traverse the granitic rock in all directions and apparently they are frequently associated with the veins of
TIN. 669
tin ore. Sedimentary rocks are commonly developed along the western flank of the ridge and lower down the slope they pass beneath the Valley limestone.
The tin ore occurs principally in well-defined quartz veins which traverse the granite in all directions and have steep though varying dips. The veins are banded and contain pyrite and arsenopyrite in addition to cassiterite. The walls of the enclosing granite are changed to greisen (quartz and fine scaly muscovite) containing a small amount of cassiterite. The veins are usually narrow not exceeding a foot and less though a greater thickness is frequent and some of the veins measure several feet across, in the veins proper, the gangue is quartz in which the cassiterite occxirs as crystals, nodules, and stringers. According to Winslow, the general char- acter of the gangue is a dark earthy rock, composed largely of quartz with pyrite, mica and various earthy minerals, among which cassiterite is disseminated in small crystals and in fine grains indistinguishable to the naked eye.
Near the surface, the vein rock is much altered and softened from weathering and is of a reddish to yellow-brown color from the oxidation cf the iron-bearing minerals. In its undecomposed or fresh condition it is readily distinguished from the enclosing country-rock. The location and character of the veins have been proved by numerous openings usually of shallow depth. Analyses have proved nearly every vein to contain tin but in many cases the quantity is reported to be very small. On the other hand many of the veins show rich returns. Through some of these, ^-einlets of solid cassiterite an inch or more thick and pockets composed of nodules of tin-stone are reported. Winslow describes numerous nodules of cassiterite the size of a hen's egg; and in one of the veins at a depth of 6 feet below the surface, he describes a block about a foot in diameter of nearly pure cassiterite.
The associated minerals so far discovered comprise wolframite, mis- pickel (arsenopyrite), pyrite, and beryl. In addition to these, siderite, limonite, chlorite, muscovite, damourite, and fluorspar have been reported found. The mispickel is reported by McCreath to contain both gold and silver.
Opening No. 1 on the Cash lands of Irish creek showed the crystalline rocks to dip nearly vertical, consisting mostly of an aggregate of quartz, feldspar and hornblende and, in places, mica-schist. The vein was com- posed of white quartz with tin ore, the largest piece of which did not exceed 2 inches in thickness and much of it was not over 1 inch. The samples assayed, showed an average of 31.60 per cent.
570 MINERAL RE80UBCE8 OF VIROINIA.
According to the prospectus of the Virginia Tin Mining and Manu- facturing Company, there is a continuous and well-defined vertical yem of crystalline cassiterite, averaging 1 inch in thickness, in one of the two trenches at opening No. 1 on the Cash lands. About a ton of ore was reported removed which yielded on assay about 76 per cent, metallic tin.
According to Professor Henr}' D. Campbell, who visited the Martha Cash mines in 1883, secured a specimen from one of the veins, which he analyzed with the following results:
Per cent.
Tin (metallic) 63.683
Iron (metallic) 1.680
Silica 416
Sulphur 0.066
Arsenic 0.301
Titanium distinct trace
In 1885, Massie described the character of the ore on the Cash lands as occurring in the form of cassiterite or black tin in sheets, strings and nodular masses, in the gangue of veins. The color of the cassiterite is from light yellowish-brown to dark brown and the ore is free from injuriou!} minerals.
Operations stopped in the Irish creek area as early as 1886, owing to the tin lands becoming involved in litigation. In 1889, a party of Boston capitalists obtained control of the Cash mines and, in 1890, they b^an operations by erecting a small concentrating plant, Sturtevant mill, a set of jigs and a vanner. At the close of 1891, the mill, located near Vesuvius, on the Norfolk and Wiestem railroad, which cost $50,000.00, was relidy. At the same time the development work put about 290 tons of rock, averaging about 3.3 per cent, of metallic tin, on the dumps. About 240 pounds of the black tin concentrates were shipped to Boston to be smelted. These are reported to have averaged only 43 per cent, of metallic tin be- cause of the arsenopyrite and ilmenite. The property again became in- volved in litigation and operations were again suspended. The vein from which the ore was obtained by the Boston parties for the above tests was 6 to 8 feet wide. The tin ore impregnates the granite on the two sides of the vein but in such small quantities as not to be workable.
The late Major Hotchkiss examined the Irish creek tin area for the I/Cxington Tin Company in 1885. A part of his report follows which is quoted from the Mineral Resources of the United States for 1886 :
"The tin ore of this region is found in the form of crystals, threads, or stringers, and in masses of varying size, disseminated in fissure veins traversing, in all directions, the granitic and other Archaean rocks that
TIN. 571
here constitute the crest and the immediate westerly slope of the Blue Bidge^ and that disappear beneath the Potsdam rocks 1 or 2 miles to the northwest of the tin-bearing field.
"The tests to prove the existence of these ores were made by sinking, driving, or cutting pits, trenches, shafts or tunnels, at the points indicated, as hereinafter described in detail, mainly in a territory about 1^^ miles long and I14 niiles wide. At other points, outside of this territory, the existence of tin ore has been proved. The character of these test works and of the ore found at each, and therefore the present condition of information about these tin ores, based on what has been actually ascer- tained about them, can best be learned by a brief statement about each of these trial works.
"No. 1. This is known as the "Cash No. 1 mine," as it is at the point on the Cash land where tin ore was first found in this region. This is an open cut about 60 feet long and from 3 to 10 feet deep, driven into the base of the spur of Cash Mountain a few feet above the level of Painter branch. The tin-bearing vein here has an average thickness of about 84 inches; this consists of tin-stone disseminated in small grains arid small pockety masses throughout a gangue of quartzose and micaceous rock that can be easily mined and crushed, and next to the wall, a per- sistent vein of solid tin-stone, or cassiterite, that averages one inch in thickness, and is sometimes 6 inches thick. Several branchings of veins from the main one, penetrating the crevices of the adjacent rocks, have also been discovered here. Portions of this large vein are occupied by masssee of quartz rock.
'Trofessor Campbell sampled 72 inches of the thickness of this vein, including the wall rock involved with the ore, and found it to contain 66 pounds of metallic tin to the ton. Mr. McCreath analyzed a sample of this ore selected by Mr. Bittenhouse 'representing all grades, from pure tin crystals to quartz and rock containing little or no tin,^ and found in it an average of 3.160 per cent, of metallic tin. The cassiterite will yield, by itself, from 66 to 70 per cent, of metallic tin.
"No. 2 embraces four openings; the second opening is a shaft 40 feet deep, said to include a vein of tin ore that is 36 inches thick at the surface and 120 inches thick in the bottom of the shaft where sinking was sus- pended. Mr. Cabell Whitehead found in an average sample of the ore of this vein, representing its whole thickness, after repeated assays, an average of 6 per cent, of metallic tin, or from 126 to 130 pounds of tin to the ton of ore. Professor Campbell made the percentage larger.
572 MINERAL RESOURCES OF VIRGINIA.
"About 3,000 pounds of the ore from this shaft were sent to England as a trial lot; the purchaser reported a considerable yield of metallic tin. I requested Mr. Massie, who selected the ore for that shipment^ to sample the ore lying scattered around this shaft for me, so as to give me what would fairly represent the ore that was shipped to England. I wit- nessed the sampling, and am satisfied that it was fairly done. This sample of several pieces I submitted to Dr. Prank W. Traphagen, analytical and consulting chemist of the Staunton Male Academy, and he found in it, after repeating his analysis, 17.64 per cent, of binoxide of tin, or 13.79 per cent, of metallic tin. Nodules of cassiterite, from small sizes up to some 12 inches in diameter, have been found in this vein ; there is no question about its richness. This shaft is on the slope of Painter mountain, and more than 400 feet above the level of Irish creek at the foot of the mountain 10 the north. No. 2a is a pit uncovering a large bowlder of quariz that is veined with crystals of tin-stone; that will probably yield as well as the vein at the shaft, or No. 2, which is 70 feet above this in altitude, the intermediate ground being strewn with tin ore. No. 2b is an open drift, at a level 90 feet below No. 2, cut for 60 feet into the slope of the mountain^ ending there about 15 feet deep, where a vein of tin ore, apparently averaging with that at No. 2, had been cut and found 108 inches thick. No. 2c is a trench on a tin-ore vein of about the same character as the preceding.
"No. 3 is some 600 feet above the level of the creek opposite, is a long tvench, about 6 feet deep, exposing some 10 feet of a vein of tin- stone that is 48 inches thick. An average sample of this ore, assayed by Prof. H. D. Campbell, yielded 0.292 per cent, of metallic tin; a sample acsayed by Prof. M. B. Hardin, at Virginia Military Institute, yielded 0.41 per cent. A quartz vein is exposed near this, resembling the one near No. 2. Traces of ore extend from this to No. 2.
"No. 4 is a shallow cut, about 1 foot deep, exposing a tin vein 12 inches thick that yielded 0.19 per cent, when assayed by Prof. M. B. Hardin.
"No. 5 consists of three pits connected by a trench. The tin vein in the middle pit is 18 inches thick; samples from this yielded 5 per cent, metallic tin in an analysis by Professor Hardin. A sample from the upper cut, or pit, an average of the ore from 6 feet of length of vein, gave 0.799 per cent, of binoxide of tin on analysis by Prof. H. D. Campbell. In the upper cut the vein is one-half inch thick at the depth of 10 feet; it be- comes thicker as it goes down, and will average 7 inches. A good many ciTstals of tin-stone are found here.
TIN. 573
"No. 6 is a pit exposing a vein 12 inches thick; it widens in going down. An average sample yielded 0.28 per cent, of metallic tin as analyzed by Professor Hardin.
"No. 7 is a pit showing a vein 18 inches thick ; it is much like No. 6 but poorer.
**No. 8 is a pit showing a vein 36 inches thick of lean ore.
"No. 9 is a pit showing a vein 4 inches thick ; ore not assayed.
**No. 10 is a shaft 40 feet deep, sunk on a vein 36 inches thick. A sample taken at the depth of 3 feet, before the shaft was sunk, representing an average of the exposed vein, yielded 1.12 per cent, of metallic tin to an assay by Dr. Dabney, of North Carolina; at a depth of 10 feet, 2 per cent, of cassiterite was found in an assay of the vein by Mr. A. D. Robert^ son. This vein is in trap rock. Three or four threads of ore come together in the bottom of the shaft.
*rNo. 11 is a pit exposing a vein 43 inches thick containing a trace of tin.
'^No. 12 exposes a vein 12 inches thick containing a trace of tin.
/^No. 13 exposes a vein 8 inches thick containing a trace of tin.
*^o. 14 is a vein 48 inches thick of lean ore between trap and granite.
"No. 15 is a trench exposing a 6-inch vein in quartz in which crystals of tin-stone are found.
"No. 16 is a tunnel in rotten granite 30 feet long, cutting a vein of lean ore from 3 to 12 inches thick.
*rNo8. 17, 18, 19, and 20 are pits exposing a 6-inch vein of lean ore.
*rNo. 21 is a tunnel driven in rotten granite some 60 feet along an 18- inch vein. Professor Hardin assayed picked samples from this vein and obtained 3% per cent, of metallic tin. Professor Campbell assayed a sample, averaging 25 feet of the length of the vein, and obtained 0.582 per cent, of metallic tin. In a pit sunk above this tunnel this vein is also 18 inches thick.
**No. 22 is a vein exposed by the roadside that is from 3 to 4 inches thick in solid rock; it is regarded as an offshoot thread from No. 21.
"No. 23 is a pit and a short tunnel on a lean 10-inch vein.
*rNo. 24 consists of two parallel veins about 10 feet apart, from 3 to 6 inches thick, which meet No. 25 ; this ore assays next to that of No. 21.
"No. 25 is a vein about 12 inches thick, which crosses and dips towards No. 24; it assays about 0.25 per cent.
**No. 26 is a tunnel about 30 feet long in a vein 24 inches thick in places; this assays 0.10 per cent.
574 MINERAL RES0UBCE8 OF VIBGINIA.
"No. 27 is a pit exposing two parallel veins about 6 feet apart^ one 4 to 6 inches and the other 12 inches thick of lean ore.
*TN'o. 28 is a pit exposing a 24-inch vein of lean ore.
"No. 29 is a drift cut some 30 feet long and over 30 feet deep at the end, exposing a vein of lean ore averaging 24 inches thick. Assays 0.10 per cent. This vein has been exposed for 400 yards, to the top of the mountain, where it is 120 inches thick; in places in the drift below it is 240 inches thick. The tin-stone here is associated with quartz and iron pyrites. It is believed that this and Nos. 30, 31, and 32 will finally come together.
"No. 30 is a vein 12 inches thick in very hard rock ; an assay of a sample gave 1 per cent., but the average will be less.
"No. 31 is a vein averaging 24 inches in thickness (36 in places). Professor Hardin obtained 0.17 per cent, of tin from an average of tiie whole vein. It also carries $1.86 of gold to the ton.
"No. 32 is a vein 48 inches thick, averaging in richness between Nos. 30 and 31.
"Nos. 33 and 34 are cuts on a quartz and pyrites vein containing traces cf tin.
"No. 36 is an outcrop of veins from which an 8-inch cubic block of crystals of tin-stone was obtained. Not opened as yet.
"No. 36 is a quartz vein 60 inches thick that yielded an average of 0.12 per cent, of metallic tin to assay of Mr. A. D. Robertson.
'^o, 37 is a vein 36 inches thick, on Mount Nettle, some 1,200 feet above Irish creek, in micaceous granite.
"No. 38 is a 10-inch quartz vein containing iron pyrites and a trace of tin.
"In the above notes the measurements of Messrs. Winslow and Robertson have been accepted and used, and the assays of Messrs. McCreath, Camp- bell, etc., as reported in published articles and as furnished to Mr. Robertson.
"The forty odd testing pits, trenches, shafts, tunnels, etc., above men- tioned, are distributed over a territory nearly 10 miles wide and 4 miles long in the north and middle spurs. Mount Maria, Cash mountain, Painter mountain, Mount Elizabeth, Little Hill and Big Hill, and Mount Nettle, all spurs of the Blue Ridge projecting between the northeasterly and the easterly head branches of Irish creek. In all of these more or less metallic tin has been found, ranging from "traces^^ up to 70 per cent. Those that have been assayed may be recapitulated as follows :
"No. 1, 0.292 to 65 or 70 per cent., 66 pounds to the ton average. "No. 2, 5 to 13.79 per cent., 126 to 130 pounds to the ton.
TIN. 575
'rNo. 3, 0.292 to 0.41 per cent.
"No. 4, 0.19 per cent.
"No. 6, 0.799 ; 17.68 poTinds of '^lack^' tin to the ton.
"No. 6, 0.28 per cent.
'No. 10, 1.12 to 2. per cent., 35 pounds of *'T)lack^* tin to the ton.
'No. 21, 0.682 to 3.26 per cent., 18 pounds of "black'' tin to the ton. "No. 25, 0.25 per cent.
'No. 26, 0.1 per cent. "No. 29, 0.1 per cent.
^^0. 31, 0.17 per cent, of tin and $1.86 of gold to the ton. "No. 36, 0.12 per cent.
"The localities of the above and the per cents, of tin are: "No. 1, on Cash mountain, 31.60 to 70 per cent. "Nos. 2 and 3, on Painter mountain, 0.292, 0.41, 13.70 per cent, '^os. 4 and 6, on Mount Elizabeth, 0.19, 0.799 per cent. '^0. 6, on Little mountain or hill, 0.28 per cent. "No. 10, on Big Hill, 1.12, 2 per cent.
"Nob. 21, 25, 26, 29, and 31, on Mount Maria, 0.17, 0.25, 0.582, 0.1, and 3.25.
**No. 36, on North Spur, 0.12 per cent.
"Omitting from the above the deposit on Cash and Painter mountains assays Nos. 1, 2, and 3, the averages of yields from the other localities do not vary greatly among themselves, showing that these ores range in rich- ness from 0.1 to 3.25 per cent.; the eleven assays of these localities averaging 0.806 per cent., or nearly 18 pounds of 'Tt^lack'* tin to the ton. 1 see no reason why an abundance of ore should not be had from these. Mount Elizabeth, Little mountain, Big Hill, Mount Maria, and North Spur veins, that will yield this average result.
"The assays of the Cash and the Painter mountain ores range in rich- ness from 0.292 to about 70 per cent., making an average for the five given of 23.218 per cent. This is probably too high an average for all the well-picked tin stone that could be obtained from these localities; and yet it would not, in my opinion, be very diflBcult to obtain from them a large quantity of ore that would run such an average. The prospecting that has been done, the condition of the veins as exposed, and their rich- ness in metallic tin, I think, warrant the conclusion that an abundance of high-grade ore can readily be obtained from these localities.
**While the developments that have been made here are by no means extensive, and are not such as one would like to see, still they cover a very
Ill
576
MINERAL BE8OOB0E8 OF TIB8INIA
coDBiderable area and fairly well expose the tin Teinf from the surface, and so that their character can be s than this, the openings that have been made are so 1 expose to inspection fully 600 feet of the vertical dt of this region, some of them having been made net creek and others near the top of the spurs more than level: horizontally these openings are many of them apart; consequendy, it ie fair to say that we have and steeply eroded or naturally trenched region, the of varying depths, iip to over 600 feet in a level coi numbers 1 and 2 are but 1,600 feet apart horizontal over 300 feet apart vertically. It is considered that their surroundings there are nearly the same data for be obtained if the shaft at No. 2 were sunk to a dep some may be said of the other localities where the posed. This knowledge has led me to the favorable pressed in reference to the quantity and the quality o
"The geological and mineralogical conditions of bearing region are similar to, if not even identical Cornwall (England) and other noted tin-producing the same crystalline and metamorphic rocks, broken, by dikes of trap, basalt, and other igneous rocks, thi conditions for the formation of tme, profitable, metall such as are cnuscd hy profound movements of the ear veins as those in which stanniferous ores of the Irii found.
"The exposure of the Irish Creek tin veins, both i unmistakably leads to the conclusion that these veins character, extent, thickness, and richness in metallic V, ith those of the famous Cornwall district of Englai conditions are better. I may add that no region ci ^■antagee for extensive mining and metallurgical ope i? all the year round salubrious and favorable for w( proper of Virginia, unlike most mountain chains, fertility and varied productiveness, and the same may Virginia, that flanks it on the east, and of the famous flanks it on the west. The forests of this region for charcoal ; and it is not far by direct railway to th and coking coals in the United States. ■
TIN. 577
*T!n conclusion, this report is emphasized by the opinion that this Irish Creek tin-bearing district, as above described, will prove abundantly productive in tin/'
Other Localities.
The occurrence of tin is reported from Nelly's Ford, near Rockfish river, in the northern portion of Nelson county. No prospecting has yet been attempted.
Bruce in his book entitled, Southwest Virginia and Shenandoah Valley, published in 1891, makes the following statement concerning tin in Clarke county (pages 234-5) : "Along the foothills of the Blue Ridge, in this county, fine specimens of copper and lead have been discovered east of the Shenandoah river, and tin has been reported to have been found on the Capon Springs property by Mr. Bale, who shipped a cargo of the ore to Wales.**
References.
Blake, W. P. Ores of Tin. Mineral Resources of the United States.
1883-84, 592-640.
Brown, W. G. On Cassiterite from Irish Creek, Rockbridge County,
Virginia. American Chemical Journal, 1884, VT» 186-187.
Occurrence of Wolframite at Irish Creek, Rockbridge County, Virginia. American Chemical Journal, 1884, VI, 185.
Campbell, H. D. Tin Ore (Cassiterite) in the Blue Ridge in Virginia.
American Journal of Science, 1884, XXVII, 411 ; The Virginias, 1883, IV, 151.
Campbell, J. L. On Dufrenite from Rockbridge County, Virginia.
American Journal of Science, 1881, XXII, 65-f>7.
Hotchkiss, Jed. The Tin Ore of Virginia. The Virginias, 1884, V,
38; Mineral Resources of the United States, 1885, 371-376.
McCreath, A. S. and Piatt. Description of Locality of Tin Ore, Rock- bridge County, Virginia. Bulletin Iron and Steel Association, 1883, 207.
Robertson, Dr. W. On Virginia Tin. Mining Journal, 1884, Oct. 18.
Rolker, Chas. M. The Production of Tin in the Various Paris of the
World. 16th Annual Repori, U. S. Geological Survey, 1894-5, Pari Til, 458-538.
/..
578 MINERAL RE80UB0E8 OF VIRGINIA.
Ulke, T. The Occurrence of Tin Ore at Kings Mountain, North
Carolina^ and Cash Mine Near Vesuvius, Virginia. Mineral Resources of the United States, 1893, 178- 183.
Whitehead, Edgar. Beport on the Martha Cash Tin Mines. Prospectus
of the Virginia Tin Mining and Manufacturing Company, 1885.
Williams, A., Jr. The Virginia Tin Mines. The Virginias, 1885, VI,
169-170.
Winslow, A. Tin Ore in Virginia. Engineering and Mining Journal,
1885, XL, 320.
The Virginia Tin Mines. The Virginias, 1885, VI, 168.
71. NICKEL AND COBALT.
General Statement.
Nickel and cobalt can best be treated together, for most of the orw containing one are apt to carry some of the other. Virginia has not, as yet, produced any appreciable quantity of either of these metals, but there are occurrences in certain localities of the State which afford promise of commercial quantities of the metals, especially nickel.
The existence of nickel in Virginia has been reported from a number of localities in the Piedmont region or crystalline area, especially in asso- ciation with many of the extensive pyrrhotite bodies of the Floyd-CarroP- Grayson plateau in southwest Virginia (map, figure 29), and in Amherst county near and to the east of Lynchburg. In Amherst county the pyrrho- tite is somewhat sparingly developed as small grains and moderate size granular masses, in crystalline schists, partly homblendic, of doubtful origin. More recently, nickel, in association with peridotite masses, has been reported from near Broadrun station, in Fauquier county, northern Vir- ginia; but this locality has not yet been investigated.
Reliable analyses of the southwest Virginia pyrrhotite bodies, giving the exact percentage of nickel and cobalt, are unfortunately not available. Recent developments in northern Floyd county, near the boundaries of Montgomery j!nd Roanoke counties, give very encouraging results of the existence of nickel in commercial quantities. This area is described belov in some detail.
In addition to the above occurrences and associations, cobalt is found in association with some of the impure earthy manganese (wad) deposit?
NICKEL AKD OOBALT.
579
of the Valley region, especially on the east side of the Valley along the western base of the Blue Bidge. The following analysis of manganese ore from the Church Mountain mine in Rockingham county, made by Professor
AkrKulut^
Fig. 99. — Map showing location of nickel and arsenic mines in Floyd coun- ty, Virginia.
580
MINERAL RB80URCE8 OF YIBOINIA.
F. W. Clarke of the TJ. S. Geological Survey, shows a noteworthy percentage of cobalt:
Per cent.
Metallic manganese 39.20
Cobalt 2.48
Iran and aluminum oxides 5.14
Insoluble matter 22.1 1
Ignition 11.30
The Floyd Connty Area.
The property, controlled by the Virginia Nickel Corporation, as indi- cated on the accompanying map, figure 99, is located in the extreme
^Small Opening O
Shop Eaclne Home
Fig. 100. — Ground plan showing location of opening^ at nickel mine on Lick Fork, near Hemlock, Floyd county, Virginia.
northern part of Floyd county, along the boundaries of Montgomery and Koanoke counties. The openings thus far made are wholly in Floyd county, the principal ones being directly on Lick Fork, within a few hundred feet of its confluence with Flat Run (figure 100), southeast head- waters of the South Fork of the Roanoke river. The Lick Fork openings' are furi;her located in a direct line from Shawsville, the nearest railway station, 7 miles nearly south-southeast
Prom 1904 until recently, the Virginia Nickel Corporation exploited the area under the name of Fidelity Exploration Company. Openings have been made at four different places, aligned along a neariy northeast- fiontliwest direction, for a distance of about 4.6 miles. Some of these are in schists and contain pyrite instead of pyrrhotite as the ore.
NICSEL AND COBALT.
681
At the Lick Fork openings, the principal ones in the area, the ore is chiefly pjrrhotite with some intermingled chalcopyrite. This occurrence ot pjrrhotite has been known for many years. The ore was dug and copperas made from it in a very crude way before the Civil War. The Lick Pork openings, shown in flgure 100 and comprising shafts and drifts, wore begun in the hard rock out-cropa at the base of a high and steep ridge, a few feet above the stream level. At the time of my visit, in May, 1907, a largo amount of ore on the dumps was reported to average by actual assays not less than 1.75 per cent, of nickel, and a fraction of 1 per cent, of copper. As mnch as 0.4 per cent, of cobalt was reported, but the average is
IT?:^
DIABWE DIKE.
NORITE DIKE,
WITH PVRAHOTrTE
AND NICKEL.
Fig. 101. — Section Bhowins structural relations of tbe rocks at uickel
mine, near Hemloclc, Hoyd county, Virginia.
considerably less. Assays of (lie pyrite from other openings in the area are reported to yield from ,3 to 4 per cent, of nickel.
Arsenopyrite (mispickel), pages 810-211, is mined less than 4 miles conthwest of the Lick Fork openings, but numerous analyses made of the ore do not show the presence of either nickel or cobalt.
The area is composed exclusively of crystalline metamorphic rock-, derived in part from original sedimenls and in part from igneous massea. The country-rook is chiefly made up of a complex of micaceous quartz- schists and gneisses of variable composition, and usually of a ])ronounced thinly foliated type. The rooks immediately associated with the ore are without exception of igneous origin, and range in composition from a pyroxene syenite to a very basic gabbro. These comprise pyroxene syenite, diabase, and gabbro. They are intruded into the schists and gneisses. The
HlNERAi BBSODRCEB OF VIKOINU
gabbro and diabase penetrate the pyroxene syenite ii are accordingly younger in age The structural rel (liabaae, and gabbro, as indicated in the larger openi sliown in figure 101. The diabase is in direct conta with the gabbro, has an average tbicknesB, so far as in depth, of from 8 to 10 feet, and an outer contac its own hanging-wall.
The mica gabbro is the ore-bearing rock, has an present main opening on Lick Fork of from 18 to diabase dips from 46° to 60° east-southeast. The rhotite chiefly and some chalcopyrite, is quite freely ont striking r^ulari^ ot uniformity, through the ge of the gabbro, Ihe proportion of sulphides is very si make np 60 per cent, and more of the total rock-mas between.
Thin sections of the ore studied under the microsi that the ore is chiefly of secondary origin. Micro6CO| from the relations of the sulphides to the rock m followed, principally, the lines of weakness in the i considerable replacement of them.
Uses. — The principal use made of cobalt is as a constituent in glass and earthen wares. Cobalt st high elastic limit and breaking strength, cannot steel on account of its high cost.
Probably the principal use made of nickel is in nickel and nickel-chromium steel. Some of the otht for large forginga, marine engines, wire cables, elec in alloys.
Keference.
Watson, Thomas L.
The Occurrence of Nickel in Vi American Institute of Mining
pages.
INDEX
Albemarle county, copper, 502-503.
Stony Point copper vein, 502-503. Albemarle county, iron, 460-470.
Stony Point mine, 469. Albemarle county slate belt, 46-47. Albemarle county, eoapstone, 291. Albemarle county, dnc and lead, 542-544. Albemarle-Nelson counties soapstone belt,
293-295. Alexandria area and vicinity, clay, 174. Allanite, 387-388.
Analyses of, 388. Alleghany county, iron mines, 438-442. Bess mine, 441. Dolly Ann mine, 439. Double Ridge mine, 441. Fancy Hill mine, 440. Given mine, 441. Horse Mountain mine, 441-442. Iron Mountain mine, 439. Iron Gate fossil ore mine, 44^. Low Moor mine, 440. Potts Valley mine, 441. Rich Patch mine, 440. Rumsey mine, 439. Stack mine, 440. Alteration, lead and zinc ores, 527. Amazonstone, 389. Ambler property, copper, 608. Amelia county area, mica, 279-284.
Amelia court-bouse district, 280-283. General geology, 280-282. Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282. Jetersville district, 283-284. Schlegal mine, 283-284. Amelia county, soapstone, 291-292. Amelia court-house district, mica, 280- 283.
General geology, 280-282.
Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282. Amethyst, 386.
Amherst county deposits, copper, 503. Amherst county, iron mines, 470-471.
Maud vein, 471.
Riverville mines, 470-471. Amherst county, manganese, 230.
Analysis of, 239. Amherst county slate belt, 47-48. Ammonia, gas, tar and, 383-384. Anaconda mine, copper, 498. Analyses, allanite, 388.
Athens shale, 135.
barite, 316-317.
calamine, 525.
calcareous marls, 399-400.
carbonite (natural coke), 379.
cement material near Harrisonbuxg^ 113.
Cbambersburg formation, 98, 99.
coal, 348-352.
coal, Richmond coal basin, 343.
coke, 381-382.
diabase, 37, 38, 39.
diatomaceous earth, 217-218.
dufrenite, 302.
feldspars, 277.
greensand marls, 398.
gypsum, 334.
helvite, 391.
Holston formation, 136-137.
iron ores, 414, 453, 457, 462.
Knox dolomite, 132-133.
T^noir limestone, 134.
Lewistown limestone, 154, 155, 156.
Liberty Hall limestone, 122.
|
limeaWne. 71. 72, 76, 80, 81, M, »8, |
Shenandoat |
|
09, 101. 104, lOB, 109, 110, US, |
sphalerite. |
|
117, IID, 122. )U3, 128, 130, 182. |
Stones Riv. |
|
134, 136. 137, 138, 139, 140, 141. |
Trenton lii |
|
151, 154, 155. 156, 167. 168, 181, |
Trenton shi |
|
182, 214. |
Analysis, apaUt |
|
liniMtone and marble, 76, 77. 80, 81. |
anhydrite, |
|
limestone (rom Covington. 156. |
Mbeatoa. 2( |
|
liiuestoncB from L«iiiigton, 122. |
BayB eanda |
|
limestone, VVsrm Springs, 154. |
bertha ipeli |
|
linieslone and ahals iie»r CraigBville, |
beryl, 387. |
|
166. |
"bucklat," , |
|
clay, gypsu |
|
|
118, lie. |
coal, 348. |
|
rieh. 167-158, |
diabaM, 38. |
|
emery, 224. |
|
|
burg, 100. |
galenite, 62 |
|
glass sand. |
|
|
gypsum, 33 |
|
|
248. 249. 250, 251, 262, 253, 264, |
baUt« (wit |
|
255. |
iron ores, 4 |
|
432. 433, |
|
|
mineral waters, 2(11-207. |
441, 442, |
|
448, 440, |
|
|
moldiDK sunds. 394-395. |
466. 460, |
|
monaj^ite, 303. |
'4«4, 466. |
|
Murat liiiiestDiie, 104. |
472, 473, |
|
natural cement rofk. Balcony Falls, |
lead coDcen |
|
101. |
Lewistown |
|
natural ceiiientB, West Virdinia- |
limestone, t |
|
Marjland, 181. |
118. 120, |
|
Newman limestone, 168. |
limestone e |
|
limestone, i |
|
|
71, 72. |
limestone, ' |
|
Ordovicinn lime^^lpnes at Ben Hur. |
manganese. |
|
151. |
680. |
|
Ordovician limestone near Stokes- |
microlite, 3 |
|
ville. 120. |
Natural Br |
|
Penriaburg limestone, 138-130. |
Nolichueky |
|
pyrile, IBS. |
ocher. 228, |
|
pyrrhotite, 208-208. |
pebble pboB |
|
residual clays. 170-172. |
Bandst«n^ 1 |
|
Bogeraville sbaie, 130. |
sipylite, 20E |
|
Russell shales, 120. |
smithsonlte, |
|
Bphalerit«, 1 |
|
|
•alt brines, 213. 215. |
atrengite, 3i |
|
Sevier shale*. 140 111. |
aysnite. 33. |
INDEX.
587
tin ore, 670.
travertine, Staunton, 160. unakite, 31. Utica shale, 102. zinc concentrates, 644. Andis mine, iron, 469. Andradite, 387. Annandale, granite, area, 29. Ann Phippe mine, copper, 614. Anthony barite mine, 311. Apatite, 387.
Analysis of, 387. Apatite and phosphatic marl, 299-302. Nelsonite (phosphate rock), 300-802. Nelson county, 300-301. Roanoke county, 301-302. Pebble phosphate, 302. Analysis, 302, Appalachian Mountain province, ooal,
347-374. Appalachian Mountain province, 7-12. Appalachian Mountain region, barite, 320-325. introduction. 320. Occurrence, 320. Russell and Tazewell counties, 822-
326. Smyth county, 321-322. Washington county, 322. Wythe county, 320-321. Appalachian Mountain region, manga- nese of, 244-266. Augusta county, 246-260.
Analyses of, 248, 249, 260. Botetourt county, 261-262.
Analyses of, 252. Description of individual areas, 244-
255. Frederick county, 252. Introduction, 244. Other Valley deposits, 264-266.
Analyses of, 154, 266. Page county, 244-246.
Analysis of, 244, 246. Rockbridge county, 263-264.
Analysis of, 253, 264. Rockingham county, 260-261. Analyses of, 261.
Shenandoah county, 262-263. Analyses of, 263.
Appalachian Mountain region, sanditonea of, 69-63.
Appomattox county, iron, 471.
Appomattox county, manganese. 239. Analyses of, 239.
Arcadia mine, iron, 446.
Area, Alexandria and vicinity, clay, 171.
granite, Annandale, 29.
Bedford county barite, 310-320.
BelEeld, clay, 186.
Bermuda Hundred, clay, 182-183.
Broadway, clay, 183.
Chester, clay, 182.
City Point, clay, 184.
Curie's Neck, clay, 181-182.
Fairfax county, granite, 28-29.
Floyd county, nickel and cobalt, 680- 682.
Fort Lee, clay, 180-181.
Fredericksburg, clay, 176.
Fredericksburg, granite, 26-28.
gneiss, Lynchburg, 33-34.
granite. Falls Church, 29.
Layton, clay, 177.
Louisa county barite, 318-319.
Milford, clay, 177.
Norfolk and vicinity, clay, 186-186.
Nottoway-Prince William counties granite. 29-30.
Oldfield, clay, 186.
Petersburg, clay, 183.
Petersburg granite, The, 19-21.
Richmond, clay. 177-180.
Richmond granite. The, 21-26.
Sturgeon Point, clay, 184.
Suffolk, clay, 186-187.
Triassic, barite, 308-309.
Wilmont, clay, 176. Areas, clay, description of, 174-187.
granite, description of, 19-33.
manganese, description of, 239-243, 244-265.
other gneiss, 34-35.
slate, description of, 42-51. ArminiuB pyrite mine, 199-201.
588
INDXX.
Arsenopyrite ( mispickel ) , 210-211. References, 211. Uses of, 211. Artesian waters, 268-275.
List of Coastal Plain formmtiona,
268. References, 276.
Water horizons in eaatem Virginia, 269-272. Chesapeake, 270-272. Pamunkey, 270. Potomac, 269-272. Wells in eastern Virginia, 272-274. Arvonia, slate, 44-45. Asbestos, 285-287.
Analysis, 286-287. Composition and character, 286. Distribution, 286-287. Occurrence, 285-286. References, 287. Uses, 287. Associated minerals, 526-527. barite, 317. ores and, zinc and lead region, 628-
527. . pyrite areas, 196-197. Associated ores, 526. Associated rocks, barite, 315-317.
Analyses of, 316-317. Athens shale, 134-135. Analyses of, 135. Augusta county, coal field of, 348. iron mines, 434-436. Bare bank mine, 435. Black Rock mine, 435. Blue bank mine, 435. Buffalo Gap mine, 434. Crozier mine, 435. Ferrol mines, 434. Fisherville mine, 435. Lofton mine, 435. Mine bank mine, 435-436. Augusta county, manganese, 246-250.
Analyses of, 248, 249, 260. Augusta county, ocher, 229-230. Austinville lead and zinc mines, 532-687. Balcony Falls, analyses of natural ce- ment rock from, 161.
Bank, Racor, manganese, 254.
Bare bank mine, iron, 435.
Barite (heavy apar), 306-827.
Appalachian Mountain r^on, SSD* 325. Introduction, 320. Occurrence, 320. Russell and Tazewell counties,
322-325. Smyth county, 321-322. Washington county, 322. Wythe county, 320-321. Composition and properties, 305. Distribution, 307. Historical, 305. Methods of mining, 325. Occurrence, 307-308. Piedmont Plateau region, 309-320. Bedford county area, 319-320. Campbell-Pittsylvania area, 809- 318. Analyses, 316-317. Associated minerals, 317. Associated rocks, 316-317. Mines, 311-314. Mode of occurrence, 314-816. Structure, 318. Louisa county area, 318-319. Preparation, 326-326. Production, 327. References, 327. Triassic area, 308-309. Uses, 326-327.
Barnes place, gypsum, 330. analysis of, 330.
Barr limonite mine, 473-474. Barr magnetite mine, iron, 473. Barren Springs mines, iron, 452. Basalt, Diabase and, 36-39. analyses of, 37, 38, 39.
Bassler, R. S., contribution of paper hj, 86.
acknowledgments to. xxx. Bath county, iron, 438. Bays sandstone, 141-142.
analysis of, 141. Bedford county barite area, 819-320.
IXDBL
591
CambriAc and OrdcTieiui strata mqUi- m^esT^rc VirpinU. difttribiitiaB of.
CambriaR fornuition>, scutbv^eytem Vir> ^nia. 12S-131.
Cambrian <Lcxrer> quartxiteft. shales and sandMones, 93.
Cambrian s^andstone, 60.
Cambro-OrdoTioian, southwestern Vir- ginia, 131.
Campbell countT. iron, 471.
Campbell county, manganese, 23J>-242, analyses of. 240-241,
Campbell county, soapstone, 291. Campbell. H. D.. acknowledgments to. 87. Campbell-Pitt $ylTania barite area. 309- 318.
Associated minerals. 317.
Associated rocks. 315-317. analyses. 310-317.
Mines, 311-314.
Mode of occurrence, 314-313.
Structure, 318. Carboniferous ( Pennsylvanian i ooaU. 353-374.
Age of the coal-l>earing rock"*, 353.
Analyses, coal. 357-358.
Big Stone Gap coal field. 3(U-373.
Character of the coal, 35rt-.'<58. analyses of. 357-358.
Coal, Carboniferous, oharai'ter of, 358-358.
Geologic relations of, 353.
Greologic relations. Carboniferous coals. 353.
Importance, location and. Carbon- iferous coals, 353.
Location and importance of. 353.
Location and importance. Carbon- iferous coals. 353.
Pocahontas or Flat Top coal field, 359-364. Introductory statement, 359. Operators, 359-3C0. The coal. 380-384.
Coals of Dismal formation. 364.
I
CixaU of l\>cahoiiia« formatk«L
C^\*U of Se^^uoyah a»d Tritov*
iVrn;aii\His, 3*4. Ooal* of Welch fonnaticvik
3ifU. i»t!H>U"^c ^K-'tion*, 3AV36L lntr\xluction. 3W. Stratigraphy. 3o4-3«V.V St ra t igra phy . i"* rboni f erou« 354-355. CarboDifer\>us »amistone», (t2 <i3. Mississippian group, ^. Pennsylvanian gnnip, <K-W. Carbonite i natural coke), 3783S0. analyses of. 379. References, 379-.'ISO. Carroll county. t»pper mint**. 51 ■! 5I6. Hotty Riker mine, 5U-51« Cranberry mine. .Ml. Gartiner and lii^ad mines, 516. Great Outburst. 5HV Vaughn mine. 514. Wildcat mine, 514. Carroll i»ounty, iron mino-i. 47»> 4J6. Betty Baker mine. 47rt. Chestnut Yard mines. 475 476. Carroll county, soapstone. 293. Carter bank, iron, 453. Cartwright and Davis, granite, quarries.
28. Castle Hock mine, inm, 446. Catlett, Charles, nokno\vle<lgments to, 87. Cedar Run mine, iron, 453. Cedar Springs zino mines, .'V3H-.540. Cement and cement mntcrials. 86-167. Cement industry in Virginia, 162* KIA. Cement, kinds of, 87-88. Cement materials, 88-89. Cement materials, cement and, 86 167. Cement materials, distribution of, R9. Cement materials near llHrrisonhuri;;, an- alyses of, 1 13. Cement materials. postOrdoviciiin, 151. Cement, natural, 160-162. Central western Virjjinia, analyses Hint-
stones and nhale of, 123. Cerussite. 523.
590
IKDKL.
Gnibb or Lynchburg mine, 443-444.
Grubb specular mine, 445.
Houston mine, 444.
Lemon mine, 445.
Oriskany mine, 443.
Ried mine, 443.
Roaring Run mine, 443.
Sand bank mines, 442.
Wilton mine, 442.
Wood mine, 446. Botetourt county, manganese, 251-252.
analyses of, 252. Bremo, slate, 46. Brines, salt, analyses of, 213-216. Broadway area, clay, 183. Buchanan and Dickenson counties, 463. Buchanan place, gypsum, 330. '•Buckfat,'' 526. Buck Hill mine, iron, 437. Buckingham county deposits, copper, 500-502.
Lightfoot mine, 501-502.
New Canton mines, 501.
United States Mineral Go's mine, 501. Buckingham county, gold mines, 562-563.
Anaconda mine, 562-563.
Apperson mine, 562-563.
Booker (Morrow) mine, 562.
Buckingham mine, 562.
Duncan mine, 562.
Ford mine, 562.
(Jamet mine, 562.
Lightfoot mine, 562-563.
TiOndon and Virginia mine, 562.
Morton mine, 562.
Mosely mine, 562.
IMiiladelphia mine, 562,
Piedmont mine, 562.
Willis Creek mine, 562. Buckingham county, iron, 470. Buckingham county, manganese, 239. Buckingham. Fluvanna and, counties,
soapstone, 290-291. Buckingham-Fluvanna slate belt, 42-46. Buena Vista mines, iron, 436. Buena Vista Plaster and Mining Go's mines, 331-334.
analyses of gypsum and anhydrite
from, 334. analysis of anhydrite from, 334.
clay from, 333. records of well borings, 331-332.
Buena Vista shales, 94.
Buffalo Gap mine, iron, 434.
Bugley mine, manganese, 242.
Buhrstones, see millstones, 401.
Building and ornamental stones, 16-86.
General statement, 16. Building sand, 395-396. Cabell mine, manganese, 242. Cabin Branch pyrite mine, 202-204. Calamine, 625. Calcareous marls, 398-400.
analyses of, 399-400. Callie mine, iron, 442. Cambrian and Ordovician formation of northwestern Virginia, 91. Lower Cambrian quartzites, shalei,
and sandstones, 93. Martinsburg shale group, 99-102. Eden shales and sandstones, 102. Trenton limestone, 100-101.
analyses of, 101. Trenton shales, 100.
analyses of, 100. Utica shale, 101-102. analysis of, 102. Massanutten sandstone group, 102-
103. Shenandoah limestone group, 93-99. Buena Vista shales, 94. Chambersburg formation. 96-99. analyses of. 98-99. Generalized section of, 97. Geologic section, vicinity of Stras-
burg, 95. Natural Bridge limestone, 94. Sherwood limestone. 94.
analysis of, 94. Stones River formation. 95-96. analysis of. 96. Table of, 92. Cambrian and Ordovician formations, southwestern Virginia, 128.
IKDSZ.
591
Cambrian and Ordovician strata south- western Virginia, distribution of, 124-128.
Cambrian formations, southwestern Vir- ginia, 128-131.
Cambrian (Lower) quartsites, shales and sandstones, 93.
Cambrian sandstone, 60.
Cambro-Ordovician, southwestern Vir- ginia, 131.
Campbell county, iron, 471.
Campbell county, manganese, 239-242. analyses of, 240-241.
Campbell county, soapstone, 291.
Campbell, H. D., acknowledgments to, 87. I
Campbell-Pittsylvania barite area, 309-
318. Associated minerals, 317. Associated rocks. 315-317.
analyses, 316-317. Mines, 311-314. Mode of occurrence, 314-315. Structure, 318.
I
Carboniferous (Pennsylvanian) coals, ■ 353-374.
Age of the coal-bearing rocks, .353.
Analyses, coal, 357-358.
Big Stone Gap coal field. 304-373.
Character of the coal, 356-358. analyses of. 357-358.
Coal, Carboniferous, chnrni'ter of, 356-358.
Geologic relations of, 353.
Geologic relations. Carboniferous coals, 353.
Importance, location and. Carbon- iferous coals, 353.
J^rocation and importance of, 353.
Location and importance. Carbon- iferous coals, 353.
Pocahontas or Flat Top coal field, 359-364. Introductory statement, 359. Operators, 369-360. The coal. 360-364.
Coals of Dismal formation, 364.
Coals of Pocahontas formation,
362-363. Coals of Sequoyah and Tellowa
formations, 364. Coals of Welch formation, 88t-
364. Geologic sections. 360-361. Introduction, 360. Stratigraphy, 354-355. Stratigraphy, Carboniferous coalt, 354-356. Carboniferous sandstones, 62-63. Mississippian group, 62. Pennsylvanian group, 62-63. Carbonite (natural coke), 378-380. analyses of, 379. References, 379-380. Carroll county, copper mines, 614-516. Betty Baker mine. 514-516. Cranberry mine, 514. Gardner and Goad mines, 516. Great Outburst, 516. Vaughn mine, 514. Wildcat mine, 514. Carroll county, iron mines, 475-4J6. Betty Baker mine, 476. Chestnut Yard mines. 475-476. Carroll county, soapstone, 293. Carter bank, iron, 453. Cartwright and Davis, granite, quarries,
28. Castle Hock mine, inm, 446. Catlett, Charles, acknowledgments to. 87. Cedar Run mine, iron, 453. Cedar Springs zinc mines, .538-540. Cement and cement materials, 86-167. Cement industry in Virginia, 162-166. Cement, kinds of, 87-88. Cement materials, 88-89. Cement materials, cement and. 86 167. Cement materials, distribution of, 89. Cement materials near Harrisonburg, an- al vses of, 113. Cement materials, post-Ordovician, 151. Cement, natural, 160-162. Central western Virginia, analyses lime- stones and shale of, 123. Cerussite, 523.
592
IKDSZ.
Chamberaburg formation, 96-99. Analyses of, 98-99. Generalized section of, 97. Chappel mine, copper, 498. Character and composition, mica, 278. Character, composition and, asbestos,
285. Character, composition and, feldspars,
275-276. Character and occurrence, Blue Ridge
copper ores, 505-506. Character and occurrence, pyrite ore,
193-197. Character and structure of rocka, Louisa
and Prince William counties
areas, 191-193. Character of vein, gossan lead, 612-513. Charlotte county, Keysville Copper area
in, 500. Chemical analyses, mineral waters, 261-
267. Chert, 216.
Chesapeake (formation), 270-272. Chester area, clay, 182. Chesterfield county, ochcr, 226-227. Chestnut Yard mines, iron, 475-476. Chickamauga limeatone, 76-77, 133-134.
analysis of, 77. Chlorophane (fluorite). 388. Circle mine, iron, 443. City Point area, clay. 184. Clarke county, iron mines. 430.
Berryville mine. 430. Clarks bank. iron. 448-449. Clarks Summit mine, iron. 459. Clasaifjoation of clays. 168-169. Classification of Virginia iron ores, 407,
408. Clay areas, description of, 174-187. Clay, definition and properties of, 167-
1G8. Clay, oripin of. 108. Clavs. 107-187.
Clays, classification of. 168-169. Clavs, roastal Plain, The, 173-187. Clays, residual, 109-172. analyses of, 170-172.
ft
Clavs. sodiiucntarv. ^72.
Clayton mine, iron, 451. Clinch sandstone, 142 Coal, 336-378.
Appalachian Mountain proyince, 347- 374. Lower Carboniferous coals, 347- 352. Augusta county, 348. Bland- W3'the counties field, 352. Botetourt, 348-349. Frederick county, 347. Montgomery - Pulaski counties
field, 349-352. Mountain Falls district, 347. North Mountain coal field, 348-
349. North River coal field, 348. Carboniferous ( Pennsy 1 vanian ) coals, 353-374. Age of the coal -bearing rocks,
353. Big Stone Gap coal field, 364- 373. Location and importance, 364-
365. The coal. 365-373.
Big Stone Gap and western portion of field, 370- 373. Coals of Wise formation,
372-373. Imboden seam, 371-372. Introduction, 370-371. Kelly seam, 372. Seam just beneath Glade- ville sandstone, 372. Eastern portion of the field, 367-370. Edwards seam, 368. Introduction, 367-368. Imboden seam (?), 369. Jawbone seam, 369-370. Kennedy seam, 369. Lower Banner seam, 368-
369. Upper Banner seam, 368. Geologic sections, 366. Operations, 367.
INDEX.
598
Character of the coal, 356-358.
analyses of, 357-358. Geologic relations, 353. Location and importance, 353. Pocahontas or Flat-Top coal field, 359-364. Introductory statement, 359. Operators, 359-360. The coal, 360-364.
Coals of Dismal formation,
364. Coals of Pocahontas forma- tion, 362-363. Coals of Sequoyah and Tel- Iowa formations, 364. Coals of Welch formation,
363-304. Geologic sections, 360-361. Introduction, 360. Stratigraphy, 354-355. Structure, 356. Distribution, 338-339. Historical, 336-338. Methods of mining, 373-374. Piedmont province, 339-347.
Coal beds of the basin, 342-346. Analyses of coal from, 343. Depth of the coal, 345-346. Extent of the coal beds, 342-345. General geology of the basin, 340-
342. Historical, 340. Mines, 346-347. Position and extent of basin, 339-
340. Richmond coal basin, 331-347. Production, 375-376. References, 376-378.
Coal and its by-products, 336-387.
Coal beds, Richmond coal basin, 342-346.
Coal, Big Stone Gap coal field, 365-373.
Coal, depth of, Richmond coal basin, 345- 346.
Coal, methods of mining, 373-374.
Coal. Pocahontas or Flat Top coal field,
3G0-304. Coals of Dismal formation. 364.
Coals of Pocahontas formation, 362-363. Coals of Sequoyah and Tellowa forma- tions, 364. Coals of Welch formation, 363-364. Coals of Wise formation, 372-373. Coastal Plain clays, 173-187. Coastal Plain counties, iron, 477. Coastal Plain fornrations, list of, 268. Coastal Plain limestones, 66. Coastal Plain province. The, 3-5.
Formations of, 4. Coastal Plain region, manganese of, 238. Coastal Plain region, marls, 397-399.
Calcareous, 308-399.
Greensand, 397-398. Coastal Plain region, sandstone of, 54-55. (^obalt {see under Nickel). Coke, 380-383.
Analyses of, 381-382.
Statistics on, 382-383. Coke, natural {see under carbonite). Colunibite, 298, 300.
analysis of, 298, 390. Composition and character, asbestos, 285. Composition and character, feldspars,
275-276. Composition and properties, barite, 305. Composition and properties, garnet, 287-
288. Composition and properties of pjnrite,
190. Composition, character and, mica, 278. Composition, mineral, granites, 18. Composition of pyrite ore, 196. Composition, talc and soapstone, 289. (^ook, granite, quarry, 20. (^)pper, 491-519.
Albemarle county deposits, 502-503.
Amherst county deposits, 503.
Blue Ridge copper deposits, 503-511. Character and occurrence of ores,
505-506. Description of mines, 506-511. Geology, 504-505. Location and history, 503.
Buckingham county deposits, 500-
Copper ores of the Triassic, 518.
Distribution of the ores, 492-494.
594
IKDKL.
Geographical, 492.
Geological, 492-494. General statement, 491. Gossan lead. 511-517.
Description of mines, 514-517. Keysville area, Charlotte county,
500. The Southwest Virginia region, 611-
517. References, 519. Virgilina district, 494-499.
Description of the mines, 496-499.
Geology and petrography, 494.
Introductory statement, 49 J.
Kinds and occurrence of ore, 494- 495.
The veins. 495-496.
Copper ores of the Triassic. 518. Copperas Hill mine, copper, 514. Corundum, 223-224. Corundum and emery, 223-224.
Corundum, 223-224.
Emery, 224.
analysis of, 224.
References, 224.
Uses of, 224. Counties west of the Blue Ridge, 429- 467.
Alleghany county, 438-442.
Augusta county. 434-436.
Bath county, 438.
Bland county, 462.
Botetourt county, 442-446.
Buchanan county, 463.
Clarke county, 430.
Craig county, 445-446.
Dickenson county, 463.
Frederick county, 429.
Giles county, 447-448.
Hif^hland county, 438.
Lee county, 405-467.
Montponiery county, 447.
Pn^e county, 431-433.
Pulaski county, 448-451.
Rcckhridpe county, 436-437.
R<ickin<;baiu county. 433-434.
Roanoko county. 446-447.
Russell county, 463.
Scott county, 463. Shenandoah county, 430-431. Smyth county, 460-461. Tazewell county, 462-463. Warren county, 430. Washington county, 461-462. Wise county, 463-464. Wythe county, 461-459.
Coyington, 166.
analyses of limestone from. 156. Craig county iron mines, 446-446.
Fen wick mine, 446.
Oriskany mine, 446. Craigsyille, 164-165.
analyses limestone and shale near, 166.
Section near, 155. Craigsyille, Portland cement plant at,
163-165. Cranberry mine, copper, 614. Crawford mine, iron, 454. Crigger bank, iron, 460. Crimora manganese mine, 246-249. Crozier mine, iron, 436-444. Culpeper county, copper, 618. Culpeper county, gold mines. 554.
Culpeper mine, 664.
Ellis mine, 554.
Richardyille mine, 554. Curie's Neck area, clay, 181-182. Curran Valley mine, iron, 461. Dayis barite mine, 313. Dayis mine, manganese, 243. Definition and properties, fullers earth,
296-297. Definition and properties, marls, 396. Definition and properties, ocher, 225. Definition and properties of clay, 167-
168. Definition, granite, 17. Delton mines, zinc, etc., 531. Deposits, copper, Albemarle county, 502-
503. Deposits, copper, Amherst county, 603. Deposits, copper. Blue Ridge, 603-611. Deposits, indiyidual, ocher, description
of, 226-231. Depth of coal. Richmond basin, 345-346.
IKDBX.
595
Description of clay areas, 174-187. Description of individual areas, manga- nese, 244-255. Description of areas of granite. 19-33. Description of individual deposits, ocher,
226-231. Description of individual manganese
areas, 230-243. Description of mines, Blue Ridge copper
district, 506-511. Description of mines, copper, southwest
Virginia, 514-517. , Description of mines, gold, 553-564. Description of mines, Virgilina district,
496-409. Description of mines, zinc and lead, 530-
544. Description of slate areas, 42-51. Details of localities, 154-156. Details of localities, northwestern and central western Virginia, 105-120. G^logic section, Wadesville, 114. Harrisonburg and vicinity, 110-113. analyses cement material near
Harrisonburg, 113. Structure sections, 112. Middletown, 107.
Section of Ordovician rocks near Middletown, 107. Mount Sidney and vicinity, 115. analyses limestone, Weyers Cave,
115. Geologic section, Mount Sidney, 115. Riverton and vicinity, 114. Staunton, 115-119.
analyses, shales and limestones, Staunton, 117, 118, 119. Strasburg, 107-109.
analyses, limestone and shales, vicinity of, 109. Wadesville, 113-114. Western edge of Valley, north of Staunton, 110-120. Greologic section, Staunton, 117. Winchester, 105-107. analysis limestone east of Win- chester, 107.
Structure section northwestern Virginia, 106. Woodstock and vicinity, 109-110. analyses of limestone, Woodstock, 110. Details of localities, southwestern Vir- ginia, 142. Developments, mining, gypsum, 329-334. Devonian sandstones, 61. Dewey mine, iron, 472. Diabase and basalt, 36-39.
analyses of, 37, 38, 39. Diamond, 385-386. Diatoraaceous earth, 216-223. Analyses of, 217-218. Distribution, 218-222. Origin and occurrence, 217-218. References, 223. Uses of, 222. Dickenson, Buchanan and, counties, 463. Dickey's Hill mines, copper, 507. Diorite, 39-40.
Dismal formation, coals of, 364. Distribution and description, 279. Distribution and localities, fullers earth,
297. Distribution and localities, gem minerals,
385. Distribution and localities, graphite, 188-
190. Distribution and localities, marls, 397-
400. Distribution and localities, ocher, 225-
226. Distribution and localities, pyrite, 101. Distribution and localities, talc and soap- stone, 200-295. Distribution, asbestos, 286-287. barite, 307. Cambrian and Ordovician strata
southwestern Virginia, 124-128. coal, 338-330.
diatomaceous earth, 218-222. etc., older crystalline limestones, 67-
72. feldspars, 276-277. garnet, 288-289. geographical, iron ores, 425-428.
|
geological, iron ores, 423-425. |
Kelly mine. |
|
gold, S49-551. |
Kirk mine, |
|
gTBDitei, IT- IS. |
Liepold mil |
|
niter, 304-305. |
Wykoff mia |
|
of cement materials, 89. |
Fauquier countj |
|
Features, surtac |
|
|
ginia, 05-68. |
Feldspar, 380. |
|
of the copper ores, 492-4B4. |
Feldspars, 27S-2 |
|
Analyse., 2! |
|
|
Geological, 492-494. |
CompoaitioD |
|
nitile, 232-234. |
Diatribution |
|
zinc and lead or«a. 520-GZl. |
|
|
District, copper, BentonHlleOverall, SOT- |
References, |
|
SOS. |
Ui«, 27T. |
|
Diversity of resources, 16. |
FenwJek mine, i; |
|
Dixie mine, iron, 436-43T. |
Eerrol mines, in |
|
Dolly Ann mine, iron, 439. |
t-isherrille mine, |
|
Dolomite, knoi, 13M33. |
Floyd county *) |
|
Dorothy mine, copper, 498. |
S80-B82. |
|
Double Ridge mine, iron, Ml. |
rioyd county, « |
|
Dressing, ore, iron, 48S-48C. |
Toncray mii |
|
Dufrenite, 302. |
Floyd county, ] |
|
analyses of, 302. |
gomcry cc |
|
Eastern portion of the BJg Ston« Gap |
I'loyd county, ii |
|
coal field, 3aT-3T0. |
Toncray mil |
|
Eden shales and sondstones, 102. |
Floyd county, sc |
|
Edith mine. iron. 444. |
l-'luorite (fluorsi |
|
Edwards coal seam, 368. |
References, ' |
|
EfTecIs of weathering and erosion, 12-14. |
Uses, 215. |
|
Elements, 188-190. |
Fluorite (chloTo |
|
Emery, 224. |
l''luvanna and C |
|
analysis of, 224. |
562. |
|
Erosion and wealherinR, effecta of. 12-H. |
Beli^ora min |
|
E«ing mine, iron, 487. |
Derthn and |
|
Fairfnx coimty area, granite. 28-29. |
Big Bird m: |
|
Annnndale area. 20. |
Bowles mim |
|
Hoffman and Miller quarry, 29. |
Bushy mine. |
|
FalU Church area. 29, |
Collins mini |
|
Trip qmirrj'. 29. |
Eudes mine. |
|
Fairfax county, pTanite. area. 28-29. |
Fisher mine |
|
Fairfax county, soapstone. 202. |
Gilmore mir |
|
Falls Church, firanitc. area, 20. |
Hughes mini |
|
Fancy Hill mine, iron. 440. |
Manning mi |
|
Farris mine, iron, 441). |
Marks mine |
|
Fnuher mine, ninnyanesp, 250. |
Moss mine. |
|
Fauquier county, gold mines. 553, |
Pace mine, 1 |
|
Bancroft mine. 553. |
Payne mine, |
|
Franklin mine, 553. |
Snead mine. |
INDBZ.
697
Tellurium mine, ff50-560. Walters mine, 559.
Fluvanna and Buckingham coimties, soapstone, 200-291.
Formation, Dismal, coals of, 364.
Formation, Holaton, 135-137.
Formation, Pocahontas, coals of, 362-363.
Formation, Welch, coals of, 363-364. Formation, Wise, coals of, 372-373. Formations, Cambrian, southwestern
Virginia, 128-131. Formations, Coastal Plain, list of, 268. Formations, Sequoyah and Tellowa, coals
of, 364. Forney openings, zinc, etc., 531. Fort* Lee area, clay, 180-181. Fossil hematite ore, 416-418. Foster Falls mines, iron, 455. Fox Mountain mine, iron, 434. Frederick county, coal field of, 347. Franklin county, copper mines, 517.
Howell mine, 517. Franklin county, iron mines, 474.
Rocky Mount mine, 474. Franklin county, soapstone, 291. Frederick county, iron, 429. Frederick county, manganese, 252. Fredericksburg area, granite, 26-28.
Cartwright and Davis quarries, 28.
Hazel Run granite, 27-28. Fredericksburg area, clay, 175. Fredericksburg granite area, 26-28. Fullers earth, 296-297.
Definition and properties, 296-297.
Distribution and localities, 297.
References, 297.
Uses, 297. Furnaces in Virginia, list of, 479. Qabbro, 40. Gale mine, iron, 446. Qalenite, 523. Ganaway mine, iron, 459. Gkingue minerals, gold deposits, 552-553. Gardner and Goad mines, copper, 516. Garnet, 287-289, 386-387.
Composition and properties, 287-288.
Distribution, 288-289.
References, 289. Uses, 289.
Gas, tar, and ammonia, 383-384.
Gem minerals, 385-391.
Distribution and localities, 385. Mineral species, 385-391. References, 391-392.
General character, graphite, 188.
General geology and stratigraphy of cen- central western Virginia, 103-105. analyses of Murat limestone, 104. analyses of Liberty Hall limestone, 105.
General geology of Virginia, 1-15. geographic position of, 1.
Generalized section, Chambersburg for- mation, 07.
Geographical distrioution, iron ores, 425- 428.
Geographical position of Vir^nia, 1.
Geological distribution, iron ores, 423- 426.
Geologic relations southwestern Virginia deposits, gypsum, 328-329.
Geologic section at Mount Sidney, 115.
Geologic section in Scott and Russell counties, 148-149.
Geologic section in Smyth county, 146.
Geologic section, Lexington and vicinity, 121.
Geologic section near Craigsville, 155.
Geologic section, north Thompson Val- ley, 144.
Geologic section, Pearisburg, 137-138.
Geologic section, Speers Ferry, 136.
Geologic section, vicinity Ben Hur, 150.
Geologic section, vicinity Lurich, 157.
Geologic section, vicinity Seven Foun- tains, 153.
Geologic section, vicinity of Strasburg, 95.
Geologic section, Wadesville, 114.
Grcologic section, Warm Springs to Mt. Grove, 154.
Geologic sections Big Stone Gap coal field. 366.
Geologic sections, Pocahontas coal field, 360-361.
598
IKDSZ.
Geology and petrography, Virgilina cop- per district, 494. Geology and stratigraphy, general, cen- tral western Virginia, 103-106. Geology, Amelia court-house mica dis- trict, 280-283. Geology, Blue Ridge copper deposits, 504-
505. Geology, general, gold, 551-553. Country rocks, 551. Gangue minerals, 552-553. Veins, 551-552. Geology, general, Richmond coal basin,
340-342. Otology y general, Virginia, 1-15. Geology, general, zinc and lead region,
521-523. Geology, gossan lead, 511-512. Geology of Louisa and Prince William counties pyrite area, 191-193. Character and structure of the rocks, 191-103. Geology of southwestern Virginia, 123. Cambrian and Ordovician forma- tions of, 128. General distribution, Cambrian and
Ordovician strata, 124-128. Major faulU, 123124. Stratigraphy, 128. Structure sections in, 125. Giles county, cement materials, 142. Giles county, iron mines, 447-448. Interior mines, 448. Johnson mine, 447. Porterfield mine, 448. Given mine, iron, 441. Gladeville sandstone, coal seam just be- neath, 372. Glass sand, 393-394. analysis of, 393. Gneisses, 33-35. Gold and silver, 549-567.
Description of mines, 553-564. Buckingham county, 562-563. Culpeper county, 554. Fauquier county, 653. Fluvanna and Goochland counties, 559-562.
Halifax county, 563. Louisa county, 557-5o9. Montgomery and Floyd countits,
664. Orange county, 555-557. Spottsylyania county, 554-555. Stafford county, 553-564. Distribution, 549-561. General geology, 551-553. Historical, 649. Production, 564-565. References, 666-667. Golleher mine, iron, 461. Goochland county, gold mines («ee under
Fluvanna county). Gossan lead, geology of, 611-512. Gossan lead, southwest Virginia, 611-517. Gossan, pyrite, 410. Gossan, pyrrhotite, 419-421. Grabill mine, iron, 466. Grace mine, iron, 443. Granites, 17-33. Definition, 17.
Description of areas of, 19-33. Blue Ridge area, 30-31. Fairfax county area, 28-29. Fredericksburg area, 26-28. Nottoway-Prince Edward counties
area, 29-30. Petersburg area, 19-21. Richmond area, 20-26. Distribution of, 17-18. Kinds of, 18. Mineral composition, 18. Granitp, Hazel Run, 27-28. Granite production in Virginia, 35. Granite quarries, list of, in Richmond
area, 23. Graphite, 188-190.
distribution and localities, 188-190. general character, 188. Occurrence. 188. References, 190. Uses, 190. Grayson county, cn;)ner, 517. iron, 470-477. soapstone. 292-293. Great Outburst, 516.
INDEX.
599
Qreat Valley region, zinc and lead, 530- 541. Montgomery county, 530. Pulaski county, 531. Roanoke and Botetourt counties,
530. Russell county, 541. Smyth county, 540-541. Wythe county, 531-540. Greenbrier limestone, 80-81, 157-158. analyses of, 81, 157, 158. geologic section of, near Lurich, 157. Greene county, copper mines, 510-511. High Top Copper Mining Go's mine,
510-511. Sims mine, 510. Greensand marls, 397-398.
analyses of, 398. Greenway mine, iron, 469-470. Gregory mine, iron, 457. Griffin mine, iron, 446. Griffin specular mine, iron, 447. Grubb or Lynchburg mine, iron, 443-444. Grubb specular mine, iron, 445. Gypsum, 327-335.
General properties, 327-328. Geologic relations southwestern Vir- ginia deposits, 328-329. Mining developments, 329-334. Analysis, anhydrite, 334. Analysis, clay, 333. Analysis, gypsum, 330-331. Analyses, gypsum and anhydrite,
334. Records of well borings, 331-332. Origin and occurrence, 328. Production, 334-835. References, 335. Uses, 334. Hairston mine, iron, 474-475. Halides, 211-216. Halifax Copper Co's mine, 498. Halifax county, gold mines, 563. €roldbank mine, 563. Howard mine, 563. Halite (salt), 211-215. Analysis of, 212-213. Analysis of limestone, 214.
Analyses of brines, 213-215.
Mathieson Alkali Works, 214-215.
References, 215. Hall mine, iron, 463. Happy creek mine, iron, 430. Harrisonburg and vicinity, 110-113.
Analyses, cement material near, 113.
Structure sections in vicinity of, 112. Hatchet barita mine, 313. Hazel Run granite, 27-28. Heiston mine, iron, 433. Helvite, 390-391.
analyses of, 391. Hematite mine, iron, 455. Henry county, iron, 475. Henry county, soapstone, 293. Henson mine, iron, 459. Hewitt barite mine, 311. High Hill mine, copper, 496-498. Highland county, iron, 438. Hightop Copper Mining Co's mine, 510-
511. Historical, barite, 305. Historical, coal, 336-338. Historical, gold, 549. Historical, iron, 402-404. Historical, Louisa county pyrite de- posits, 198. Historical, Richmond coal basin, 340. Historical, tin, 568.
Hoffman and Miller, granite, quarry, 29. Holden, R. J., contribution of paper by, 402-491.
Acknowledgments to, xxx. Holston formation, 135-137.
analyses of, 136-137.
Geologic section, Speer Ferry, 136. Holston mine, iron, 462. Home bank, iron, 460-461. Honaker limestone, 131. Horse Mountain mine, iron, 441-442. Houston mine, iron, 444. Houston mine, manganese, 251-252. Howell mine, copper, 517. Hurst mine, iron, 454. Hydrocarbons, 336-384. Ilmenite (menaccanite), 232. Imboden coal seam, 369, 371, 372.
600
INDBZ.
Importance, location and, Big Stone Gap coal field, 364-365.
Impurities of iron ore, 405-407.
Indian Camp mines, iron, 456.
Individual mines, iron, 428-477.
Interior mines, iron, 448.
Iron, 402-491.
Blue Ridge hematite, 418-410. Blue Ridge limonite ore. 414-416. Classification of Virginia ores, 407- 408.
Coastal Plain counties. 477. Counties west of the Blue Ridge, 429-
467. Fossil hematite, 416-418. Geographical distribution, 425-428. Geological distribution, 423-425. Historical, 402-404. Impurities of iron ore, 405-407. Individual mines, 428-477. Limestone limonite ores, 410-414. Limestone magnetite, 422. List of furnaces in Virginia, 479. List of iron mines in Virginia, 477-
478.
Methods of mining, 470-485.
Minerals and ores, 403-406.
Ore dressing, 485-486.
Origin of iron ore, 407.
Oriskany ore, 408-410.
Piedmont counties. 468-477.
Piedmont magnetites, 421-422.
Production, 487-488.
Pyrite gossan, 419.
Pyrrhotite gossan and pyrrhotite,
419-421. References, 488-401. Titaniferous magnetite. 422-423. Uses, 480.
Irondale mines, iron. 404.
Iron Gate fossil ore mine, 441.
Iron minerals and ores, 403-405.
Iron mines in Vir<;inia, list of. 477-478.
Iron Mountain mine, iron, 439.
Iron ores, analyses, 414, 453, 457, 462.
Iron ores, analysiB, 410, 416, 418, 419,
430, 432, 433, 434. 435, 436, 439,
440, 441, 442, 443, 444, 445, 446,
447, 448, 449, 450, 451, 452, 453,
454, 455, 456, 457, 458, 459. 461,
463, 464, 465. 466, 467, 469. 470,
471, 472, 473, 474, 475. 476, 477.
Ironville mine, iron, 472.
Ivanhoe mine, iron, 457.
Jawbone coal seam, 369-370.
Jefferson mines, mica, 282.
Jetersville district, mica, 283-284. Schlegal mine, 283-284.
Johnson mine, iron, 447.
Johnson shaft, copper, 501.
Jura-Cretaceous sandstone, 54-55.
Kelly coal seam, 372.
Kelly mine, manganese, 250.
Kendall and Flick mine, manganese, 250-
251. Kennedy coal seam, 369. Keystone mine, iron, 464. Keysville area, copper, Charlotte county,
500. Kimball mine, manganese, 245. Kinds and occurrence of ores. Virgilina
district, 494-495. Kinds of cement, 87-88. Kinds of granite, 18. Kinds of ore, manganese, 237-238. Kirkbride mine, copper, 514. Knox dolomite, 131-133.
analyses of, 132-133. Kyanite, 388.
Lassiter, granite, quarries. 20. I^avine mine, iron. 465. Layton area, clay, 177. Lead ( see under Zinc ) . Lead and zinc ores, alteration of, 527. Lead ores, 523.
Cerusaite, 523.
Galenite, 523. Lee county, cement materials, 149-151.
analyses of Ordovician limestonei in, 151.
Geologic section in, 150.
601
Lee county, iron mines, 466-467.
Ben Hur mine, 466.
Boones Path mines, 466-467.
Ewing mine, 467.
Grabill mine, 466.
Lavine mine, 465.
Noes Siding mine, 466.
Pennington mine, 465.
Truro mine, 466. Leets mine, manganese, 240-241. Lemon mine, iron, 445. Lenoir limestone, 134.
analyses of, 134. Lewistown limestone, 77-80, 151-156.
analyses of, 80, 153, 154, 155, 156.
Geologic sections of, 153, 154, 155. Lexington, 120-123.
analyses of limestones from and near, 122-123.
Geologic section, Lexington and vi- cinity, 121. Liberty mines, iron, 431. Lightfoot mine, copper, 501-502. Limestone, analyses of, 214. Limestone, Chickamauga, 133- 134.
Covington, analyses of, 156.
east of Winchester, analysis of, 107.
Greenbrier, 157-158.
Honaker, 131.
Lenoir, 134.
Lewistown, 151-156.
Lexington, analyses of, 122-123.
limonite ores, 410-414.
magnetite, 422.
Marysville, 130.
Moccasin, 139-140.
Newman, 158.
Newman, analyses of, 168.
Ordovician, near Stokesville, analy- ses of, 120.
Pearisburg, 137-139.
Rutledge, 129.
Shenandoah, analyses of, 162.
Weyers Cave, analyses of, 115.
Woodstock at, analyses, 110. Limestones and marbles, 66-86.
Coastal Plain region, 66.
Distribution of, 65-66.
Mountain province limestones, 73-83. Chickamauga limestone, 76-77.
analysis of, 77. Greenbrier limestone, 80-81.
analyses of, 81. Lewistown limestone, 77-80.
analyses of, 80. Marble, 82-83.
Cave (onyx) marbles, 83. Shenandoah (Valley) limestone, 74-76. analyses of, 75. Piedmont Plateau region, 66-73. Newark (Jura-Trias) limestoneB,
73. Older crystalline limestones, 67- 72. analyses of, 68, 70, 71, 72. Distribution, occurrence, etc.,
67-72. General properties, 67. Marble, 69-70. Verd antique, 70. Production, 84.
Properties, composition, etc., 65. References, 86. Uses, 83-84. Limestone and shale near Craigsville,
analyses of, 165. Limestones and shales, central western
Virginia, analyses of, 123. Limestones and shales, Staunton, analy- ses of, 117, 118, 119. Limestones and shales, vicinity Lurich,
analyses of, 167-168. Limestone and shales, vicinity Strasburg,
analyses of, 109. Limestones, Mississippian, 156-159. List of Coastal Plain formations, 268. List of furnaces in Virginia, 479. List of iron mines in Virginia, 477-478. List of producing mineral springs, 260-
261. List of soapstone quarries, 295. Little Wythe mine, iron, 458. Localities, details of, 164-156. Localities, distribution and, fullers earth, 297.
|
LocUitiM, diatributiou and, gem min- |
Location, |
|
eralB, 366. |
Smith mi |
|
Sulphur I |
|
|
400. |
Prince Will |
|
Cabin Bn |
|
|
226. |
Louisa county b |
|
Localities, diatribution and, of pyrite, |
I»uisa county, i |
|
191. |
Louisa county, I |
|
Localities, distribution and, Ulc and |
Low Moor mine, |
|
HoapatoDe, 290-206. |
Lower Banner o |
|
Localities, aouthwegteni Virginia, d<MU |
Lower Cambriai |
|
of, 142. |
sandstonei |
|
Localities, tin, other, 677. |
Lower Carboni |
|
Looation and history. Blue Ridge copper |
coals. 347 |
|
deposits. 603. |
Blaod-Wyth |
|
Location and importance Big Stone Gap |
analyses < |
|
coal fleld. 304.3S6. |
Montgomery |
|
Location t^uixa county pyrite deposits. |
349-362 |
|
1B8. |
analyses < |
|
Locust Hill mine, iron, 46». |
|
|
Lofttm mine, iron. 436. |
Frederick |
|
Loudoun county, copper. 61B. |
North Moui |
|
Loudoun county, iron, 488. |
Botetourt |
|
Loudoun county, ocher. 227-228. |
analysi, |
|
Louisa county. ^Id mines. 667-669. |
North Rivei |
|
Allah Cooper mine. 668. |
AugusU < |
|
Chick mine. 650. |
analyaei |
|
Cooper, 668. |
Lurich. geologic |
|
Harris mine. 666. |
analyses of |
|
Louisa mine. 659. |
I57-15S, |
|
Luce mine. 558559. |
Lynchburg, pnei! |
|
Slate Hill mine, 669. |
Maddox barite i |
|
Tinder ilat« mine, 558, |
Madison county, |
|
Walton mine, 558, |
Blue Ridge |
|
Warren Hill mine. 559. |
610. |
|
Louisa county pyrite deposits. 108-202, |
Stony Man |
|
.ArminiuN mine. 199-201. |
Magnetite limesl |
|
Historical, 198. |
Magnetite, titan |
|
Location. 198. |
Magnetites, Pied |
|
.Smith mine, 201. |
Major faults. IS |
|
Sulpliur mines, 201.202. |
Manassas Gap ci |
|
Louis* and Prince William counties py- |
|
|
rite areas, KPolopj- of. 191-193. |
mines, 25i |
|
Louisa »nd Princ^e William counties py- |
Manganese oxide |
|
rite deposits. 198-204. |
|
|
Louisa county. 108-202. |
266. |
|
-\rminiu3 mine. 199-201. |
Descriptic |
|
HMorioal. 198. |
244-2 |
INDSZ«
608
Augusta county, 246-250.
analyses of, 248, 249, 250. Botetourt county, 251-252.
analyses of, 252. Frederick county, 252. Other Valley deposits, 254-255.
analyses of, 264-256. Page county, 244-245.
analysis of, 244-245. Rockbridge county, 253-254.
analyses of, 253-254. Rockingham county, 250-251.
analyses of, 251. Shenandoah county, 252-253.
analyses of, 253. Introduction, 244.
Coastal Plain region, 238.
Introduction, 235-236.
Kinds of ore, 237-238.
Methods of mining, 255-256.
Occurrence, 236-237. Piedmont region, 238-243. Description of individual areas, 239-243. Amherst county, 239.
analysis of, 239. Appomattox county, 239.
analyses of, 239. Buckingham county, 239. Campbell county, 239-242.
analyses of, 240-241. Nelson county, 242-243. analyses of, 242-243. Pittsylvania county, 243. analyses of, 243. Introduction, 238. Preparation of the ore, 266. Production, 257-258. References, 258-269. Uses, 256-257.
Marble, 69-70, 82-83.
Cave (onyx) marbles, 83. Verd antique, 70.
Marbles, limestone and, 65-85.
Marls, 396-401.
Definition and properties, 396.
Distribution and localities, 397-400. Coastal Plain region, 397-399. Calcareous, 398-399. Greensand, 397-398. Valley region, 399-400. Origin and occurrence, 396-397. References, 400. Uses, 400. Martin prospect, zinc, etc., 530. Martinsburg shale group, 99-102. Trenton shales, 100. analyses of, 100. Mary creek mine, iron, 437. Marysville limestone, 130.
analyses of, 130. Massanutten sandstone group, 102-103. Materials, cement, 88-89. Mathieson Alkali Works, 214-215. Maud vein, iron, 471. May mine, iron, 463. McCloy, granite, quarry, 24. McGowan, granite, quarry, 24. Mcintosh, granite, quarry, 24-25. McKenna shaft, copper, 501. Mease barite mine, 313. Mecklenburg county, iron, 470. Menaccanite (ilmenite), 232. Metallic minerals, 402-682. Methods of mining barite, 325. Methods of mining coal, 373-374. Methods of mining iron, 479-486. Methods of mining manganese, 255-256. Methods of mining pyrite, 204. Methods of mining the ore, zinc, 544-545. Mica, 278-286.
Amelia county area, 279-284. Character and composition, 278. Distribution and description, 279. Occurrence, 278-279.
Amelia court-house district, 280- 283. General geology, 280-282. Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282.
|
Jeteraville district, 2SS-28i. |
copper, K! |
|
SchlegBl rnina, 2S3-2H. |
copper, Li |
|
FroductioD, 284. |
copper, M |
|
copper. Si |
|
|
Vv», 2S*. |
copper, 8t |
|
Mio mines, 282-283. , |
copper, Ti |
|
Uicm »chist, 35. |
copper, T< |
|
MicroliU, 389-390. |
copper, Ui |
|
MAlTxis of, 390. . |
601. |
|
Hiddeadorf, grauiU. qiun?, 25. |
copper, Vi |
|
Middletown, 107. |
copper, Vi |
|
Section or OrdoHcian rooks nasr. |
copper Wi |
|
107. |
copper, W |
|
HidTkle mine, iron, 437. |
Iron, Audi |
|
MJlford ares, clay, 177. |
iron. Area |
|
Milling process, rutile, 234. |
iron. Bare |
|
Milling, p;riU, 206-208. |
iron. Ban |
|
Millstones (buhratones), 401. |
iron, Barr |
|
Production, 401. |
iron. Bell |
|
Mine, bank mine, 436-43H. |
|
|
barite, Anthony, 311. |
iron, Berr |
|
bsrit«, Bennett, 312, 313, 314. |
iron, Beas |
|
barite, Berger, 312, 313. |
iron, Bett; |
|
barite, Davis, 313. |
iron, Beye |
|
bariU, Hatchet, 313. |
iron. Big |
|
barite, Hevitt, 311. |
iron. Big |
|
barite, Maddoi, 314. |
iron. Blad |
|
barite. Mease, 313. |
iron. Blue |
|
barite, Parker, 312. 313. |
iron. Buck |
|
barite, Phillips, 311. |
iron. Buffi |
|
barite, Ramsay, 312. 313. |
iron, Calli |
|
barite. Saunders, 311. |
iron, Cast! |
|
iron, Ceda |
|
|
barite, Wright, Dryden. 312. |
iron. Cirel |
|
barite, Wright. Tom, 313. |
iron. Clay |
|
copper. Anaconda. 498. |
iron. Crav |
|
copper, Ann Fhippi, S14. |
iron. Croi: |
|
copper, Betty Baker, 514-616. |
iron, Curr |
|
copper. Blue Ridge Co's, 609-SlO. |
iron. Dew. |
|
copper. Chappel, 498. |
iron. Dixii |
|
copper. Copperas Hiil, 614. |
iron, Doll] |
|
copper. Cranberry, 614. |
iron, Doul |
|
copper, Dorothy. 400, |
iron, Edit! |
|
copper, Halifax Copper Co"s. 498. |
iron, Ewii |
|
copper, High Hill, 406-498. |
iron. Fane |
|
copper, Hightop Mining Co's, 610- |
iron. Farr |
|
511. |
iron. Fenw |
|
copper. Howell, 517. |
iron, Fieh. |
I, Fox Hountain, 434.
I, Qale, 44a.
1, Oanftwaj', 4SQ.
I, Givfti, 441,
I, Golleher 46l.
I, Orabill, 466.
1, Grace, 443.
1, Greenwaj, 4119-470.
I, Oregoiy, 467.
1, Griffin, 446.
t. Griffin specular, 447.
I, Gnibb or Lynchburg, 443-444.
1, Grubb specular, 44S.
I, Bairaton, 471-475.
I, Hall, 4S3.
I, Happy creek. 430.
I, HeiatoD, 433.
I, hematite, 4S6.
I, Hanson, 4S9.
L, Holaton, 462.
rse Moimlnln. 441-44S.
cm, 444, , •l,'i4.
., lliir^t , Iron Gate fossil ore, , Iron Mountain, 439. 3Tille, 472.
I, Ivanhoe, 467.
I, Johnaoti, 447.
1, Keystone, 464,
I, Lavine, 466.
1, Lemon, 446.
1, Little Wfthe, 468.
I, Loeutt Hill, 45B.
I, Lofton, 436.
I. Low Moot-, 440.
I, Mary creek, 437.
I, May, 463.
I, Midvale, 437.
L, Mine bank, 436-430.
I, Morrii, 463.
I, Noes Siding, 406.
L, Norma, 468.
I, Oriskany, 443-440,
I, Piiinter, 457.
I, Patterton, 464.
I, Pennington, 406,
I, PerciTal, 469.
I, Pit Spring, 433.
3n, PittBville, 472-473. iron. Poplar Camp, 450.
m. Porter, 468.
)n, Porterfleld, 448.
}n, Posey, 466.
m. Potts Valley, 441. iron, Radford furnace, 449. I, Bich Hill, 440-460. I, Bich Patch, 440. iron, Bied, 443. iron, Rileyville, 432-433. iron, Bcuiring Bun. 443. iron. Rocky Mount, 474. , Borer, 440. , Rumaey, 430. iron. SanderB, 463.
>n. Stnck, 440,
)n, gtarkey 447
in. Stony Point, 409.
>n, Tasker, 449.
m, Taylor's Valley, 462.
>n. Tipfcin, 454-4SS.
)n, Toncray 475,
>n, Truro, 460.
in. Under Bock, 460-461.
ID, Vaughn, 433.
in, Walton, 463.
in. West, 431.
m, William Jackson, 460.
m, Wilton, 442.
m. Wood, 446. iron, Teary, or Bunn, 464. manganese. Bishop, 241. manganese. Blue, 260. manganese, Bugley, S4S. msnganese, Cabell, 242. manganese, Crimora, 246-249. manganese, Davii, 243. manganese, Fauher, 260. manganese, Houston, 261-262. manganese, Kelly, 260. manganese, Kendall and Pliek, !
261. manganese, Kimball, 246. manganese, LeetEt, 240-241. manganese, 'N^eHton. 250. manganese, Old Dominion Go's, ' manganese, Paddy Mills, 262.
606
IKDXX.
manganese. Piedmont Manganese
Go's, 240-241. manganese, Saunders, 241-242. manganese, Simpson. 242-243. mica, Berry, 282. mica, Pinchback, 283. mica, Schlegal. 283-284. mica. Winston, 282. pyritc, Arminius, 199-201. pyrite. Cabin Branch, 202-204. pyrite, Smith, 201. Mines, barite, 311-314.
Beverley, Kimball, and Shenandoah
Iron Works, 432. copper, description of, southwest
Virginia, 614-517. copper, Dickey's Hill, 607. copper, (Gardner and Groad, 616. copper, New Canton, 601. description of, Blue Ridge copper
district, 506-611. description of, zinc and lead, 630-
544. gold, description of, 563-564. iron. Barren Springs, 462. iron, Bertha, 462-453. iron, Boones Path, 466-467. iron. Buena Vista, 436. iron, Chestnut Yard, 475-476. iron, Ferrol, 434. iron, Foster Falls, 456. iron, Indian Camp. 456. iron. Interior. 448. iron, Irondale. 464. iron. Liberty, 431. iron, Oreton, 464. iron, Peak Knob, 451. iron. Reed Island, 450. iron, Rivorville, 470-471. iron. Sand bank, 442. iron. Sininierinan, 457. iron, Sisk and Gray. 457-458. iron, Victoria, 436. iron, in Virginia, list of. 477-478. lead and zinc, Austinville, 532-537. manganese. Manganese Corporation
of Virginia, 250. mica. .lefferson. 282.
mica, Rutherford, 282. Richmond coal basin, 346-347. Sulphur. 201-202. Virgilina district, description of,
496-499. zinc. Bertha, 532. zinc. Cedar Springs. 538-640. dnc, Dalton, 631. zinc, New River Mineral Go's, 538. zinc. Rye Valley Mining Go's, 640. zinc, Wythe lead and zinc, 468.
Mineral and Artesian waters, 259-275. Mineral waters, 259-268. Chemical analyses, 261-267. List of mineral springs produeing,
260-261. Production, 267. References, 268. Artesian waters, 268-275.
List of Coastal Plain forroationfl,
268. Water horizons in eastern Vir^ ginia, 269-272. Chesapeake, 270-272. Pamunkey, 270. Potomac, 269-270. References, 276.
Wells in eastern Virginia, 272-274. Mineral composition, granites, 18. Mineral springs, producing, list of. 260-
261. Mineral waters. 259-268.
Chemical analyses, 261-267.
List of producing mineral springs,
260-261. Production. 267. References, 268. Mineralogieal and chemioil character,
tin. 567-568. Minerals and ores of iron. 403-405. Minerals, a^^sociated, 526-527. Minerals, associated, barite, 317. Minerals, associatetl. pyrite areas, 196-
107. Minerals, gangiie, gold deposits. 552-553. Minerals, metallic, 402-582. Mining, barite, methods of, 326. Mining, coal, methods of, 373-374.
INDEX.
607
Mining developments, gypsum, 329-334. Mining, iron, methods of, 479-485. Mining, manganese, methods of, 255-266. Mining, pyrite. methods of, 204. Mining, zinc, methods of, 544-645. Mississippian limestones, 166-169. Moccasin limestone, 139-140.
analyses of, 140. Mode of occurrence, barite, 314-315. Mode of occurrence, pyrite, 190-191. Mode of occurrence, zinc and lead ores, 627-628.
Oxidized ores, 628.
Sulphide ores, 627-628. Molding sand, 394-395.
analyses of, 394-395.
physical tests of, 395. Monazite, 303.
analyses of, 303. Montgomery and Floyd counties, gold,
664. Montgomery county, iron, 447. Montgomery county, zinc, etc., 530. Montgomery-Pulaski counties coal fields 349-352.
analyses of coal from, 362. Moonstone, 389. Morris mine, iron, 453. Mount Sidney and vicinity, 116.
analysis limestone, Weyers Cave, 116.
Geologic section at, 115. Mountain, Appalachian, province, 7-12. Mountain Falls district, coal, 347.
Frederick county, 347. Mountain province limestones, 73-83.
Chickamauga limestone, 76-77. analyses of, 77.
Greenbrier limestone, 80-81. analyses of, 81.
Lewistown limestone, 77-80. analyses of, 80.
Marble, 82-83.
Cave (onyx) marbles, 83.
Production, 84.
References, 85.
Shenandoah (Valley) limestone, 74- 76.
analyses of, 76.
Uses. 83-84. Natural Bridge limestone, 94.
analysis of, 94. Natural cement, 160-162.
analyses of, and rock, 161. Natural cement rock, Balcony Falls,
analyses of, 161. Natural cements, West Virginia-Mary- land, analyses of, 161. Natural coke (see under carbonate). Netherwood, granite, quarry, 26. Nelson-Albemarle counties soapstone belt,
293-296. Nelson county, iron mines, 469-470.
Greenway mine, 469-470. Nelson county (phosphate rock), 300-
301. Nelson county, soapstone, 291. Nelson ite (phosphate rock), 300-302.
Nelson county, 300-301.
Roanoke county, 301-302. Newark (Jura-Trias) limestones, 73. Newark (Jura-Trias) sandstones, 58-69. New Canton mines, copper, 501. Newman limestone, 168.
analyses of, 168. New River Mineral Co's mines, zinc, 538. Newton mine, manganese, 250. Nickel and cobalt, 678-582.
Floyd county area, 580-682.
General statement, 578-680.
Reference, 582. Niobates and Tungstates. 298-299.
Columbite, 298. analysis of, 298.
References, 299.
Sipylite, 298. analysis of, 298.
Wolframite, 299. Niter (potassium nitrate), 304-305.
Distribution, 304-305.
Properties and occurrence, 304.
References, 305. Nitrates, 304-305. Noes Siding mine, iron, 466. Nolichucky shale, 131.
analysis of, 131.
608
Norfolk area and vicinity, clay, 186-186. Norma mine, iron, 468. North Mountain coal field, 348-349. Botetourt county, 348-349. analysis of coal from, 348.
North River coal field, 348. Augusta county, 348. ' analyses of coal from, 348.
Northwestern Virginia, Cambrian and Ordovician formations of, 91.
Northwestern Virginia, structure sec- tions in, 106.
Nottoway-Prince Edward counties area,
granite, 29-30. Wingo quarry, 30. Occurrence, 278-279.
and origin, talc and soapstone, 290.
asbestos, 286-286.
barite, 307-308.
barite, Appalachian region, 320.
etc., older crystalline limestones,
67-72. feldspars, 276. graphite, 188.
lead and zinc ores, 627-628. manganese oxides, 236-237. mode of, barite, 314-316. origin and, diatomaceous earth, 217-
218. origin and, gypsum, 328. origin and, marls, 396-397. origin and, ocher, 225. properties and, niter, 304. proporties and, rutile, 232. pyrite, mode of, 190-191. tin, 568-577. Ocher, 225-232.
Definition and properties, 226. Description of individual deposits,
226-231. Distribution and looalities, 226-226. Origin and occurrence, 225.
Aurnista county, 229-230.
Cliesterfiold county, 226-227.
T.oudoun county, 227-228.
Pa*.'e county, 228. niiMlvsis of. 2*28.
Rockbridge county, 231. Rockingham county, 229.
analysis of, 229. Warren county, 231. analysis of, 231. References, 231-232. Uses, 231. Old Dominion Manganese Go's mine, 249. Older crystalline limestones, 67-72. analyses of, 68, 70, 71, 72. Distribution, occurrence, etc., 67-72. General properties, 67. :Nfarble, 70. Verd antique, 70. Older crystalline quartzites, 55-67. Oldfield area, clay, 186. Operators, Pocahontas coal field, 359-
360. Openings, copper, other, 498. Openings, copper, Stony Man, 510. Openings, zinc, etc., Fom^, 531. Operations, Big Stone Gap coal field, 367. Orange county, copper, 618.
Taylor's copper mine, 518. Orange county, gold mines, 555-567. Chicago- Virginia mine, 556. Grasty mine, 555. Greenwood mine, 556. Melville mine, 556. Orange Grove, 556. Piedmont Mining and Metallurgical
Corporation, 556-557. Randolph mine, 556. Vaiicluse mine, 556-567. Ordovician, Cambrian and, formations of
northwestern Virginia. 91. Ordovician rooks, near Middletown, sec- tion of, 107. Ore dressing, iron, 485-486.
hematite. Blue Ridge, 418-419. hematite, fossil, 416-418. iron, impurities of, 405-407. iron, origin of, 407. iron, Oriskany. 408-410. limonite. Blue Ridge, 414-416. manganese, preparation of, 256. pyrite, 193-107. pyrite, associated minerals, 196-197.
INDEX.
609
pyrite, character and occurrence of,
193-197. pyrite, composition of, 196. zinc, methods of mining, 544-545. Ore-bodies, pyrite, genesis of, 197. Ores and associated minerals, zinc and
lead region, 523-527. Ores, associated, 526.
copper. Blue Ridge, character and
occurrence, 606-506. copper, distribution of, 492-494. copper, Triassic, 518. iron, Virginia, classification of, 407-
408. lead, 523.
lead and zinc, alteration of, 527. lead and zinc, origin of, 529-530. limonite, limestone, 410-414. relations of, to geologic structures,
629. zinc, 524-526.
zinc, preparation and smelting, 545- 646. Oreton mines, iron, 464. Origin and occurrence, gypsum, 328. Origin and occurrence, marls, 396-397. Origin and occurrence, ocher, 225. Origin and occurrence of diatomaceous
earth, 217-218. Origin, occurrence and, talc and soap- stone, 290. Origin of clay, 168. Origin of iron ore, 407. Origin of the ores, zinc and lead, 529-
530. Oriskany iron ore, 408-410. Oriskany mine, iron, 443-446. Ornamental (building and) stones, 16-
85. Other gneiss areas, 34-36. Other localities, tin, 577. Other openings, copper, 498. Other Valley deposits, manganese, 254-
255. Oxides, 216-275. Oxidized ores, zinc and lead, occurrence,
528. Paddy Mills Manganese mine, 252.
Page county, copper mines, 509.
Virginia Consolidated Copper Co's mine, 509. Page county, iron mines, 431-433.
Beverley, Kimball, and Shenandoah Iron Works mines, 432.
Beyer mine, 432.
Heiston mine, 433.
Pit Spring mine, 433.
Rileyville mine, 432-433.
Vaughn mine, 433. Page county, manganese, 244-245.
analysis of, 244-245. Page county, ocher, 228.
analysis of, 228. Painter mine, iron, 457. Pamunkey (formation), 270. Parker barite mine, 312-313. Patrick county, iron mines, 474-475.
Hairston mine, 474-475. Patrick county, soapstone, 293. Patterson mine, iron, 454. Peak Knob mines, iron, 451. Pearisburg, geologic section at, 137-138. Pearisburg limestone, 137-139.
analyses of, 138-139.
Geologic section at, 137-138. Pebble phosphate, 302.
analysis of, 302. Pennington mine, iron, 466. Pennington shale, 158-159. Percival mine, iron, 469. Petersburg area, clay, 183. Petersburg area, granite, 19-21.
Cook quarry, 20.
Lassiter quarries, 20.
Petersburg Granite Go's quarries, 20-21.
Petersburg Passenger Go's quarry, 21. Petersburg Granite Go's, granite, quar- ries, 20-21. Petersburg Passenger Go's, granite, quar- ry, 21. Phillips barite mine, 311. Phosphate, pebble, 302. Phosphate rock (nelsonite), 300-301. Phosphates, 299-304.
610
INDSX.
Physical tests, molding sand, 395.
Piedmont counties, iron mines of, 468- 477. Albemarle county, 469. Amherst county, 470-471. Appomattox county, 471. Bedford county, 471-472. Buckingham county, 470. Campbell county, 471. Carroll county, 475-476. Floyd county, 475. Franklin county, 474. Grayson county, 476-477. Henry county, 475. Loudoun county, 468. Louisa county, 469. Mecklenburg county, 470. Nelson county, 469-470. Patrick county. 474-475. Pittsylvania county. 472-474. Spottsylvania county, 46S-469. Stafford county, 468.
Piedmont magnetites, 421-422.
Piedmont Manganese Co's mine, manga- nese, 240-241.
Piedmont or crystalline region. 542-544. Albemarle eountv, 542-544.
Pi«Himont plateau limestones, 66-73.
Newark (Jura-Trias) linicstones. 73. Older crystalline limestones. (J7-72. Distribution, occurrence, etc.. 67- 72. analyses of. 08. 70, 71, 72. General properties. 67. .Marble, 09-70. Verd antique, 70.
Piedmont plateau province. The. 5-7.
Piedmont plateau region, l)arite. 300-320.
Piedmont plateau, sandstones and quartz- ites of, 55-59.
Piedmont province, coal, 339-347. Piedmont re;iion. manganese of, 238-243. Description of individual areas, 239- 243. Amherst c<mnty, 239. analvsis of, 239.
Appomattox county, 239.
analyses of, 239. Buckingham county, 239. Campbell county, 239-242.
analyses of, 240-241. Nelson county, 242-243. analyses of, 242-243. Pittsylvania county, 243. analyses of. 243. Introduction, 238. Pinchback mine, mica, 283. Pit Spring mine, iron, 433. Pittsville mine, iron, 472-473. Pittsylvania county, iron mines, 472-474. Barr limonite mine, 473-474. Barr magnetite mine, 473. Pittsville mine, 472-473. Pocahontas formation, coals of, 362-363. Poplar Camp mine, iron, 456. Porter bank, iron. 460. Porterfield mine, iron, 448.* Porter mine, iron, 458. Posey mine, iron, 456. Position and extent, Richmond coal
bafiin, 339-340. Position, geographic, of Virginia, 1. Post-Ordovician cement materials. 151. Potomac formation, 269-270. Potsdam sandstone (quartzite), 60. Potts Valley mine, iron, 441. Preparation and smelting the ores, zinc,
545-546. Preparation, barite. 325-326. Preparation of the ore, manganese, 256. Prince William county pyrite deposit, 202-204. Cabin Branch mine, 202-204. Prince William, Louisa and, counties py- rite areas, geology of. 191-193. Prince W^illiam-StafTord counties slate
belt, 51. Production, barite. .327. coal, 375-376. gold, 564-565. granite, 35. gypsum, 334-335. iron, 487-488. limestone, 84.
INDSX.
611
manganese, 257-258.
mica, 284.
mineral waters, 267.
pyrite, 206-207.
sand, 396.
sandstone in Virginia, 64.
soapstone, 296.
slate, 51. Properties and occurrence, niter. 304. Properties and occurrence of rutile, 232. Properties, composition and, barite, 305. Properties, composition and, garnet, 287-
288. Properties, composition and, pyrite, 190. Properties, definition and, clay, 167-168. Properties, definition and, fullers earth,
296-297. Properties, definition and, ocher, 225. Properties, definition and, marls, 396. Properties, general, gypsum, 327-328. Property, copper. Ambler, 608. Property, copper, Rudacill, 607. Property, copper, Sealock, 507. Province, Appalachian Mountain, The,
7-12. Province, Coastal Plain, The, 3-5.
Formations of, 4. Province, Piedmont Plateau, The, 5-7. Pulaski county, iron mines, 448-451.
Clarks bank, 448-449.
Clayton mine, 451.
Farris mine, 449.
Peak Knob mines, 451.
Radford Furnace mine, 449.
Reed Island mines, 450.
Rich Hill mine, 449-450.
Tasker mine, 449.
Under Rock mine, 450-461. Pulaski county, zinc and lead. 531.
Delton mines, 531.
Forney openings. 531. Pyrite, 190-207.
Composition and properties, 190.
Distribution and localities, 191.
General geology of areas of, 191-193.
Genesis of ore-bodies, 197.
Louisa county pyrite deposits, 198- 202.
I
Anninius mine, 199-201.
Historical, 198.
Location, 198.
Smith mine, 201.
Sulphur mines, 201-202. Methods of mining, 204. Milling, 205-206. Mode of occurrence, 190-191. Prince William county, 202-204.
Cabin Branch mine. 202-204. Production, 206-207. References, 207. The ore, 193-197. Uses, 206.
Pyrite, analyses of, 196.
Pyrite, gossan, 419.
Pyrrhotite, 208-209.
analyses of, 208-200. References, 209.
Pyrrhotite gossan and pyrrhotite, 419- 421.
Quarries, granite, Cartwright and Davis,
28. Quarries, granite, Lassiter, 20. Quarries, granite, list of. in Richmond
area, 23. Quarries, granite, Petersburg Granite
Go's, 20-21. Quarries, Richmond Granite Go's, 26. Quarries, soapstone, list of, 295. Quarry, granite. Cook, 20.
granite, Hoffman and Miller, 29.
granite, McCloy, 24.
granite, McGowan, 24.
granite, Mcintosh, 24-26.
granite, Middendorf, 25.
granite, Netherwood, 25.
granite, Petersburg Passenger Co*s, 21.
granite. Trip, 29.
granite, Wingo, 30.
granite, Winston and Co., 26.
granite, Wray, 26. Quartz, 216, 386. Quartzites, sandstones and, 52-64. Radford furnace mine, iron, 449. Ramsay barite mine, 312-313.
612
INDEX.
Rappahannock county, copper mines, SOS- SOD.
Ambler property, 608.
Manassas Gap copper mine, 508-509. Razor bank, manganese, 254. Records of well borings, gypsum, 331-332. Reed Island mines, iron, 450. Reference, nickel and cobalt, 582. References, arsenopyrite, 211.
artesian waters, 275.
asbestos, 287.
barite, 327.
carbonite (natural coke), 379-380.
cements and cement materials, 165- 167.
clay, 187.
coal, 376-378.
copper, 519.
corundum and emery, 224.
crystalline siliceous rocks, 40-41.
diatomaceous earth, 223.
feldspars, 277.
iluorite (fluorspar), 215.
fullers earth, 297.
garnet, 289.
gem minerals, 391-392.
gold, 566-567.
graphite, 190.
gypsum, 335.
halite (salt), 215.
iron, 488-491.
limestone, 85.
manganese, 258-259.
marls, 400.
mica, 285.
mineral waters, 268.
niobates and tungstates, 299.
niter, 305.
ocher, 231-^32.
phosphates. 303-304.
pyrite, 207.
pyrrhotite, 200.
rutile, 235.
sandstone, 64.
slate, 52.
soapstone. 206.
tin. 577-578.
zinc and lead, 547-548.
Relation of ores to geologic structure,
529. Residual clays, 169-172.
analyses of, 170-172. Resources, diversity of, 15.
Value of, 15. Rich Hill mine, iron. 449-450. Rich Patch mine, iron, 440. Richmond area, clay, 177-180. Richmond coal basin, 331-347.
Coal beds of, 342-346.
Analyses of coal from, 343. Depth of the coal, 345-346. Extent of the coal beds, 342-345.
General geology of, 340-342.
Historical, 340.
Mines, 346-347.
Position and extent, 339-340. Richmond area, granite, 21-26.
McCloy quarry, 24.
McCrOwan quarry, 24.
Middendorf quarry, 25.
Netherwood quarry, 25.
Richmond Granite Go's quarries, 25- 26.
Winston and Go's quarry, 26.
Wray quarry, 26. Richmond area, list of granite quarries
in 23. Richmond granite area. 21-26. Richmond Granite Go's quarries, 26. Hied mine, iron, 443. Hies, H., acknowledgment to, xxx.
Contribution of paper by, 167-187. Rileyville mine, iron, 432-433. Riverton and vicinity, 114. Riverville mines, iron, 470-471. Roanoke county, iron mines, 446-447.
Castle Rock mine, 446.
Gale mine. 446.
Griffin mine, 446.
Griffin specular mine. 447.
Rorer mine. 446.
Starkey mine, 447. Roanoke county (phosphate rock), 301-
302. Roanoke and Botetourt counties, zinc, etc., 530.
INDEX.
613
Bonsack prospect, 530.
Martin prospect, 630. Roaring Run mine, iron, 443. Rockbridge county, iron mines, 436-437.
Buck Hill mine, 437.
Buena Vista mines, 436.
Dixie mine, 436-437.
Mary creek mine, 437.
Midvale mine, 437.
Victoria mines, 436. Rockbridge county, manganese, 253-264.
analysis of, 263-254. Rockbridge county, ocher, 231. Rockingham county, iron mines, 433-434.
Fox Mountain mine, 434. Rockingham county, manganese, 260-261.
analyses of, 251. Rockingham county, ocher, 229.
analysis of, 229. Rogersville shale, 129-130.
analyses of, 130. Rocks, associated, barite, 316-317. Rocks, coimtry, gold area, 661. Rocks, siliceous crystalline, 17. Rocks, trappean, 36-41. Rocky Mount mine, iron, 474. Rock salt, analysis of, 212-213. Rorer mine, iron, 446. Rudacill property, copper, 607. Rumsey mine, iron, 439. Russell and Tazewell counties, barite,
322-325. Russell county, iron mines, 463.
Hall mine, 463. Russell county {see Scott and Russell
counties). Russell county, zinc, 541. Russell shales, 128-129.
analyses of, 129. Rutherford mines, mica, 282. Rutile, 232-235.
Distribution, 232-234.
Milling process, 234.
Properties and occurrence, 232.
References, 235.
Uses, 234-235. Rutledge limestone. 129.
analyses of, 129.
Rye Valley Mining Go's mines, zinc, 540. Salt, rock, analysis of, 212-213. Salt brines, analyses of, 213-215. Sand, 392-396.
Building, 395-396. Glass, 393-394. Molding, 394-395. Production, 396. Sand bank mines, iron, 442. Sanders mine, iron, 453. Sandstone, Bays, 141-142. Sandstone, Clinch, 142. Sandstones and quartzites, 52-64.
Appalachian Mountain region, 59-63. Cambrian sandstone, 60. Potsdam sandstone (quartzite), 60. Carboniferous sandstones, 62-63. Mississippian group, 62. Pennsylvanian group, 62-63. Devonian sandstones, 61. Introductory statement, 59-60. Silurian sandstones, 61. Coastal Plain region, 54-65.
Jura-Cretaceous, 54-55. General properties, 52-53. General statement, 53. Piedmont Plateau region, 66-69. Newark (Jura-Trias) sandstones,
58-69. Older crystalline quartzites, 55-67. Production, 64. References, 64. Uses, 63. Saunders barite mine, 311. Saunders manganese mine, 241-242. Schlegal mine, mica, 283-284. Scott and Russell counties, cement ma- terials, 148-149. Geologic section in, 148-149. Scott county, iron, 463. Sealock property, copper, 507. Seam, Edwards, coal, 368. Seam, Imboden, coal, 369, 371, 372. Seam, Jawbone, coal, 369-370. Seam just beneath the Gladeville sand- stone, 372. Seam, Kelly, coal, 372.
Section. OrJovii
Kennwly, coal, 389. S«am, Lowpr Banner, coal, 368-309. Seam. Upper Banner, coal, 368. Section, (^neralized, Chambersburg tor-
97.
- Middle-
107.
Sections, geologic, Big Stone Qap coal
field, 3sa. Sedimentnry clajB, 172. Sequoyah nnil Tellowa foimations, coala
of, 304. Seven Fountains, analfeis of limestone
Geologic section, vicinity of, 1S3. Sevier shales, 140-141.
nnalyses at, 140-141. Shale, Athens, 134-135. Shale, limestone and,
nnalyses of. 165. Shale. lim^Blones and, central western
Virginia, analyses of, 123. Shale, Noiiehiicky, 131, Shale, Pennington. 158-160. Shale. RogerBville, 120-130. Shales, limestone and. vie
(inalyses of, 157-168. Shales. liiiTfKtones and, Staunton.
ACS of. 117, 118. 110. Shales, limestones and,
burg, analyses of. ShnlcH, RuBsell. 128-12!t. Shalen, Sevlei. 140-141. Shenandouh rounly, iron
' Craigsville,
nity Lurich,
inaly-
Stras-
I. 430-431.
, 431.
Shenandonh county, manganese. 252-253.
analyse-, of, 253, Shenandouh (Valley) limestone. 74-78.
nnalysBH of, 75. Shenandonh timestone, analyses of, 102. Shenandouh limestone group, fi3-9fl. I Vista =:iales, 84. Chnmbersburg formation, 96-00. Genernlined section of, 97. analyses of. 08-99. Geologic section, vicinity of Stras- burg. 05.
Natural Brid{
Sherwood limi
Stones Kiver
analyses of,
Sherwood limestoi
Silica, 216-223.
Chert, 216.
DiatomaceouB
Analyses of;
DistribuUon
Origin and
References,
Uses of, 221
Quartz, 216.
Silicates, 276-297.
Siliceous erystsillii
Silurian sandstone
Silver (see under
Simmennaa mines
Simpson mine, ma
Sims mine, copper
Sipylite, 208.
analyses of, 2 Sisk and Gray mi Slate, 41-62.
Description ol Albemarle c Amherst coi Buckingham
Bremo, 41
Fauquier re
Prince Wii
biOt, 51.
Pn.duction, 51
References, 52
Smith pyrite mint
Smithsonite, 524-6
.Smyth county, bai
Smyth county, cen
Geologic seelii
Smyth county, iro
Crifrper bank.
Curran Vallpi
Home bank, 4
Porter bank, -
INDSX.
616
Smyth county, zinc and lead mines, 540- 541. Rye Valley Mining Go's mines, 540. Virginia Lead and Zinc Co., 541.
Soapstone, Albemarle county, 291. Amelia county, 291-292. Bedford county, 291. belt, Albemarle-Nelson counties, 293-
295. Campbell county, 291.
distribution and localities, 290. Carroll county, 293. Fairfax county, 292. Floyd county, 293. Fluvanna and Buckingham counties,
290-291. Franklin county, 291. Henry county, 293. Louisa county, 292. Nelson county, 291. Patrick county, 293. Production, 296. Quarries, list of, 295. References, 296. Talc and, 289-296. Uses, 295-296.
Southern Gypsum Co*s mine, 330-331.
Southwestern Virginia, Cambrian and Ordovician formations of, 128.
Southwestern Virginia, details of locali- ties, 142.
Southwestern Virginia, structure sections
in, 125-145. Southwest Virginia copper region, 511- 517. Description of mines, 514-517. Carroll county, 514-516. Floyd county, 517. Franklin county, 517. Grayson county, 517. General character of the vein, 512-
513. General geology, 511-512. General statement, 511. Gossan lead, 511-617. Speers Ferry, geologic sections, 136. Spelter, 547.
Sphalerite, 524. Spottsylvania county, 468-469. Spottsylvania county, gold mines, 554- 555.
Chicago- Virginia mine, 555.
Goodwyn mine, 555.
Grindstone Hill mines, 555.
Higgins mine, 555.
Johnston mine, 655.
Mitchell mine, 555.
Pulliam mine, 555.
United States Mining Go's mine, 554- 555.
Whitehall mine, 555. Springs, mineral, producing, list of, 260-
261. Stack mine, iron, 440. Stafford county, iron, 468. Stafford county, gold mines, 553-554.
Eagle mine, 553-654.
Lee mine, 554.
Monroe mine, 554.
Rappahannock mine, 554.
Rattlesnake mine, 554. Staples mine, copper, 501. Star key mine, iron, 447. Statistics on coke, 382-383. Staunton, 115-119.
analyses, limestones and shales at, 117, 118, 119.
Geologic section at, 117. Staunton, analysis of travertine from,
160. Staunton, north of, western edge Valley,
119-123. Stones River formation, 95-96.
analyses of, 96. Stony Man openings, copper, 510. Stony Point copper vein, 502-503. Stony Point mine, iron, 469. Strasburg, 107-109.
analyses, limestones and shales, vi- cinity of, 109. Strasburg, geologic section in the vicinity
of, 95. Stratigraphy, southwestern Virginia, 128. Strengite, 303.
analysis of, 303.
structure, Campbell-Pitt^lvania bariU
area, 318. Structure, geologic, relation of ores to,
SZ9. Structure aectiona in vicinity of Harri-
aonbuTg, 112. Structure sections, north weatern Vir- ginia, 106. Structure eections, south western Vir- ginia, 126-146. Sturgeon Point area, clay, 164. Suffolk area, clay, 1B6-187. Sulpha raen idee, Bulphides and, 100-211. Sulphates, 306-336.
Sulphides and sulph arsenides, 190-211. Sulphide ores, zinc and lead, occurrence,
627-628. Sulphur mines, 201 202. Surface, features of, 1-12.
Appalachian Mountain province, 7-
12. Coastal Plain province. 3-5.
Formations of, 4. Piedmont Plateau province, 6-7. Syenite, 31-33. Table of Cambrian and Ordovician for-
matione, 92. Talc and soapstone, 280-296. Talc and soapstone, composition of. 289. Tale, distribution and localities, 290. Tar, (Gas), and ammonia, 383-384. Ta«kcr mine, iron. 449. Tassin, Wirt, acknowledgments to. 87. Taylor's copper ni
■on, 462. t materials,
144.
Geolo);ic section in, 144. Tawwell county, iron mines, 482-483. Belt Hilt mine. 463. May mine, 463. Titzewell. KubscII and. counties, bariti
322-326. The Virgilina copper district, 494-499. Description of the mines, 496-499. Historical. 496. Individual mines. 496-499. Geology and petrography, 404.
4»S. The veins, * Thompson barit« Thompson Vallej
of, 144. Tin, 687-678.
Hiatorical, 6
Mineralogies
ter, 667-6(
Occurrence, I
Other localit
References, I
Tipton mine, iro
TitaniferouB ma(
Toneray mine, o
Toncray mine, ir
Trappean rocks,
Diabase and
Diorite, 39-4
Gabbro, 40.
References, 4 Travertine depos
analysis of, Trenton limes ton
Trenton shales, :
Trip, granite, qu
Triassic area, ba
TriasBtc copper (
Culpeper coi
Loudoun coi
Truro mine, iron Tungstates, Niob Unakite, 30-31. Under Rock min United States M
501, Upper Banner « Uses, arsenopyri asbestos, 28' barite, 326-; corundum a diatomaceou
INDBX.
617
feldspars, 277.
fluorite (fluorspar), 216.
fullers earth, 207.
garnet, 289.
graphite, 190.
gypsum, 334.
iron, 486.
limestone, 83-84.
manganese, 256-257.
marls, 400.
mica, 284.
ocher, 231.
pyrite, 206.
rutile, 234-235.
sandstone, 63.
soapstone, 295-296. Utica shale. 101-102.
analysis of, 102. Valley deposits, other, manganese, 254-
266. Valley region, maris, 399-400. Value of resources, 15. Vaughn mine, copper, 514. Vaughn mine, iron, 433. Vein, copper. Stony Point, 602-503. Vein, gossan lead, character of, 612-613. Veins, copper, Virgilina district, 496-496. Veins, gold, 551-562. Verd, antique marble, 70. Victoria mines, iron, 436. Virginia, cement industry in, 162-166. Virginia, central western, general geology
and stratigraphy of, 103-106.
Virginia, central western, limestones and shale, analyses of, 123.
Virginia Consolidated Copper Co*s mine,
509. Virginia Lead and Zinc Co., 541. Virginia, list of furnaces in, 479. Virginia, list of iron mines in, 477-478. Virginia, nortnwestem, Cambrian and
Ordovician formations of, 91.
Virginia, northwestern, structure sec- tions in 106.
Virginia, Portland cement plant, 163-165.
Virginia, western, clay, 187.
Wadesville, 113-114.
Geologic section at, 114.
Walton mine, iron, 453. Warm Springs to Mt. Grove, geologic section along, 154.
analyses of limestone from, 164. Warren county, copper mines, 506-608.
Bentonville-Overall district, 607-508.
Dickey's Hill mine, 507.
Rudacill property, 507.
Sealock property, 507. Warren coimty, iron mines, 430.
Big Ike mine, 430.
Happy creek mine, 430. Warren county, ocher, 231.
analysis of, 231. Washington county, barite, 322. Washington county, cement materials,
144-146. Washington county, iron mines. 461-462.
Golleher mine, 461.
Holston mine, 462.
Taylor's Valley mine, 462. Water horizons in eastern Virginia, 269- 272.
Chesapeake, 270-272.
Pamunkey, 270.
Potomac, 269-270.
Weathering and erosion, effects of, 12-14.
Welch formation, coals of, 363-364.
Well borings, gypsum, records of, 331- 332.
Wells in eastern Virginia, 272-274.
West mine, iron, 431.
West Virginia-Maryland natural cements, analyses of, 161.
Western edge of Valley, north of Staun- ton, 119-120. analysis limestone near Stokesville,
120. Structure sections near Stokesville, 120.
Western Virginia, clay, 187.
Wild Cat mines, copper. 514.
William Jackson mine, iron, 456.
Wilmont area, clay, 176.
Wilton mine, iron, 442.
Winchester, 105-107.
analysis of limestone east of, 107.
Wingo, granite, quarry, 30.
WiDston a Winaton i
id Co.. ({TuiiiM, quarry, 2S.
Irondale mines, 464.
Keystone mine, 4S4.
Oreton mines. 464.
Veary or Bunn mine. 464. Wise formation, ronii of, 372-3(: Wolf Pit mine, copper. 514. Woltnimite. 2i>0. Wood mine. iron. 445. Woodalopk nnd vicinity, 100-110.
Hnalysen of limpxtone at, 110 Wray. jirHnitc. quarry. 26. Wright, Dryiirn. bar Wriphl. Tom. bnrite tiiitie. 313. Wythe I'oiinty, liarite, ;i20-32I. Wytlie poinity. IphiI nnd r.inc mi
312.
r>4n.
Aii-lin
e Ipnd and z
Bcrlha /inc mines. 532. Cedar sprlnf,'" line mineti. 638-6 New RiviT Sliiiernl Co's miiicii. ; Wythp eoiinty. iron mines, 461-460.
Barren Pimnpi mines, 452. Berthn mine', 4rr2-4.'i3. CiiilPr bnnk. 45:i.
Cedii Chirks
liiir
. -1.13,
■. 45it,
Painter mine, Patterson min
Poplar Camp
Sanders mine,
Sim merman n
Sisk end Grai
Tipton mine.
Walton mine,
William Jacki
Wythe lead ai
Wythe lead and zi
Veary or Bunn mi
Zinc and lead, 620
Alteration of
Bertha line si
DeM'ription ol
The Great
The Piedmi
Distribution,
(lenernl g«olo.
Historical, 52
Mode of oceui
MHliods of m
Orfs and a?$
527.
.Vwociated •
Oriyin of the Preparation a Iteferenees. 54 Relation of o) Spelter, 547. rir ores, 624-520 ■■lluekfat," 52
Calaii
«S'