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PHYSICAL SCIENCES LIBRARY
UNIVERSITY OF CALIFORNIA
DAVIS, CALIFORNIA 95616
STATE OF CALIFORNIA
DEPARTMENT OF NATURAL RESOURCES
GEORGE D. NORDENHOLT, Director
DIVISION OF MINES
Ferry Ruilding, San Francisco
WALTER W. BRADLEY
State Mineralogist
San Francisco]
BULLETIN No. 108
[November, 1934
Mother Lode Gold Belt
of California
By CLARENCE A. LOGAN
'""^Z':!'^
4156
CALIFORNIA STATE PRINTING OFFICE
HARRY HAMMOND, STATE PRINTER
SACRAMENTO, 1935
O.CD. LIBRART
TABLE OF CONTENTS
Page
LETTER OF TRANSMITTAL 5
INTRODUCTION 7
Foreword 7
Definition 8
History 8
Acknowledgment __- 12
MINES ____13-190
El Dorado County 13
Introduction 13
Lode Mines 15
Seam Mines 43
Table of Mines and Prospects 48
Amador County 55
Geology 55
Geography, Climate, Water, Timber, Power __ 58
Mines 59
Table of Quartz Mines and Prospects __ 117
Calaveras County 125
Geology __ 125
Geography, Climate, Water, Power, Timber 125
Transportation __ 126
Mines 127
Tuolumne County __ 153
Geology __ 153
Ores 154
Geography, Climate, Water, Timber __ 155
Mines 155
Table of Mines 174
Mariposa County 180
Foreword 180
History — The Fremont Grant 180
Geology — __ 181
Geography, Climate, Water, Power, Timber 182
Mines 183
METALLURGY 191
BIBLIOGRAPHY 214
INDEX 221
(3)
PLATES
Page
I. Geologic Map of Mother Lode Gold Belt In pocket
II. Map of Mother Lode Gold Belt in El Dorado County, showing Min-
ing Claims and Areal Geology — __ In pocket
III. Map of Mother Lode Gold Belt in Amador County, showing Min-
ing Claims and Areal Geology — In pocket
IV. Section through Patton Shaft, Keystone Mine, Amador County, look-
ing south __ Facing page 94
V. Longitudinal Section in the plane of the Empire Vein, Plymouth
Mine, Amador County Facing page 110
VI. Map of Mother Lode Gold Belt in Calaveras County, showing Min-
ing Claims and Areal Geology In pocket
VII. Claim Map, Angels Camp Section of Mother Lode, Calaveras County
Facing page 144
VIII. Map of Mother Lode Gold Belt in Tuolumne County, showing Mining
Claims and Areal Geology In pocket
IX. Plan and Sections, California General Mining Co., Ltd., Jumper :Mine,
Tuolumne County Facing page 168
X. Map of Mother Lode Gold Belt In Mariposa County, showing Mining
Claims and Areal Geology In pocket
ILLUSTRATIONS
Page
Index map, showing location of Mother Lode __ 10
Hadsell Mill at Beebe Mine, Georgetown 16
Open cut, Beebe Mine, Georgetown 18
Montezuma-Apex Mine, Nashville 32
A view of the Mother Lode in Amador County 56
Argonaut Mine and Mill, near Jackson 64
Headframe, Central Eureka Mine, showing skip runway in form of a bridge truss 76
Headframe, Old Eureka Mine, Sutter Creek 79
Headframe, Kennedy Mine 86
Kraut 6-cell flotation unit in mill of Kennedy Mine, Jackson, Amador County__ — 89
Underground scene, Old Eureka Mine of Central Eureka Mining Co., Amador
County . 100
South face, 8th floor, 1635 ft. on 2300 ft. level, Old Eureka Mine, at Sutter Creek,
Amador County __ 102
Distribution of gold and structural features of tvpical quartz vein enclosed in
slate, Plymouth Mine 108
Generalized geological map of Carson Hill, Calaveras County 124
Open cut or glory hole on Morgan Claim of Carson Hill Co 130
Mill of Carson Hill Gold Mines Co., Inc., at Melones, Calaveras County 132
Open cut on Santa Cruz Claiin of Calaveras Group of Carson Hill Gold Mines,
Inc., looking southerly 136
Mill of Senator Mining Co., at Quartz Mountain, Tuolumne County, Table Moun-
tain skyline in background 172
Section across veins in New Pine Tree Tunnel 188
Flow sheet of Amador Metals Reduction Co 194
Flow sheet of Amador Consolidated Mill 196
Flow sheet, Dutch-App Mill, Tuolumne County 198
Flow sheet, Treasure Mill, Amador County 200
Flow sheet, Belmont-Shawmut Mill, Tuolumne County 201
Flow sheet. Central Eureka Mining Co., Amador County 202
Tailing disposal from mill of Central Eureka Mine, Sutter Creek, Amador County 203
Flow sheet, Amador Star Mill, Amador County 204
Flow sheet, Montezuma-Apex Mill, El Dorado County 206
Flow sheet, Carson Hill jMines, Calaveras County 208
Flow sheet, Beebe Mill of Pacific Mining Co., El Dorado County 209
Flow sheet, Kelsey Mining Co., El Dorado County 210
Flow sheet, Senator Mine, Tuolumne County 211
Flow sheet, Pacific Mining Co.'s Pine Tree and Josephine Mill, Mariposa County. 212
(4)
LETTER OF TRANSMITTAL
To His Excellency,
The Honorable Frank F. Merriam,
Governor of California.
Sir: I have the honor to herewith transmit Bulletin No. 108 of
the Division of Mines, State Department of Natural Resources, on the
subject of "Mother Lode Gold Belt of California."
In all of the important placer-gold producing districts of Cali-
fornia in the 50 's and 60 's search was early begun to find the so-called
' ' mother ' ' vein or lode as the source from which the gold in the gravels
had been derived by Nature's process of erosion. Success rewarded
these searches in many places. One of the two most productive dis-
tricts came to be known as the ''Mother Lode Gold Belt," extending
through the counties of El Dorado, Amador, Calaveras, Tuolumne and
Mariposa. It is not a single vein or lode, but a zone or belt up to a
mile wide for a distance of 120 miles from northwest to southeast,
within which are separate and discontinuous veins of gold-bearing
quartz.
This belt has been described and mapped in previous publications
by both the California State Mining Bureau and the U. S. Geological
Survey ; and so great has been the demand and interest in these reports
that none of them are any longer available for distribution and second-
hand copies are at a premium. For this reason and to record recent
developments the within bulletin is presented, w^hich is the result of
some six years of records researching as well as field examinations by
Mr. Clarence A. Logan, district mining engineer, in the Sacramento
office of the Division of Mines. It is accompanied by geological and
claim maps. It is particularly opportune at this time of renewed and
expanding economic interest in gold mining in California and the West.
Respectfully submitted.
George D. Nordenholt,
Director, State Department of Natural Resources.
(5)
P«>'SICALSCIC..C«,,=
UNIVERSITY OE A.? ^'''"'>'
'^^'^CA^.^H.^M^'S-
INTRODUCTION
Foreword
Of the numerous reports published upon the geology and mines
of the Mother Lode, none have covered its entire length with sufficient
detail. The first official report was that of Dr. John B. Trask, the first
State Geologist, published in 1853. Others by the same author fol-
lowed in the next three years. They describe a few of the principal
mines.
The Second Geological Survey, headed by Professor J. D. Whitney,
began work in 1861. His valuable contributions to science were halted
in 1874 by refusal of the Legislature to allot more money for the
survey, or to even approve printing results of the work of his staff;
these books were later printed by Harvard University. From 1867
to 1876 the U. S. Commissioner of Mineral Statistics prepared reports
of mine production. In 1880 the State Mining Bureau was established.
From that time its reports have given a partial record of the State's
mining industry, interrupted and restricted by lack or curtailment
of funds and by changes in political policy. Notably, between 1896
and 1914, a period of great activity in the State's gold quartz and
drift mining, only one small bulletin on quartz mines, that dealing
with the Mother Lode, was published. During the period from 1880 to
1900 the U. S. Geological Survey mapped the principal gold mining
regions of California in its geologic folios and covered the geology
in some of the annual reports. The field covered was so large, how-
ever, that very little detailed treatment of individual mines was given.
Since 1914 the State Mining Bureau (now State Division of Mines)
has published a fairly continuous record of the principal mining opera-
tions, but as is usual when changing legislatures must be depended on
for funds, the appropriations, especially since 1922, have not been
adequate to do justice to the industry. At present, everything pub-
lished on the Mother Lode except a few of the later county chapters
published by the State Division of Mines in Mining in California is
out of print, including the recent excellent work by Knopf. The
mass of information on the subject is therefore only obtainable piece-
meal in the larger libraries; and even after perusing everything avail-
able there, the searcher will feel a lack of those details so much sought
after by the mining investor looking for new fields.
The present bulletin is intended to supply such details as grade and
character of ores, working costs and production figures. Some atten-
tion will be given to geologic factors which seem to have had a bearing
on vein formation and ore deposition. It seems strange that in spite
of the mass of published data on this lode, several of these factors have
been ignored. The report will be an exposition of the actual results
of mining and such value as it may prove to have will be due to the
effort made to give the mining investor, engineer and mine manager
those data so essential in forming judgments.
(7)
» INTRODUCTION
Definition
The geologic aspects of the Mother Lode are so varied that only one
definition, that based on geologic structure, is generally applicable
to the entire lode. This may be stated as follows :
The Mother Lode is a belt of country from a few hundred feet to
two miles wide, on the western slope of the Sierra Nevada, where the
forces of mountain making, batholithic intrusion and subsequent adjust-
ment in a great mountain system have led to extensive folding and
faulting, of which the surface traces and shallower aspects follow lines
of structurally weak rocks or contacts in most places. These struc-
turally weak sections have been especially favorable for deposition
of ore which has occurred as a result of repeated movements, and the
incursions of mineralizing solutions.
In length, the Mother Lode has been proven by the finding of
payable mines for a distance of 120 miles in a direction about parallel
to the main axis of the Sierra Nevada, north of northwest. That the
same geologic formations conspicuous on the Mother Lode continue on
the strike northwest after being interrupted in Placer, Nevada and
Yuba counties by outliers of a granitic batholith, has been noted by
the present author in Butte and Yuba counties in mine workings
where the surface is covered by andesite, but these limited exposures
have not so far shown payable orebodies.
The distinguishing characteristics of the Mother Lode are uniform
strike, north to northwest; uniform dip east or northeast at a rather
steep angle, 50° to 80°, and association with certain rocks of slaty
or schistose character, particularly Mariposa clay slate (Jurassic),
altered andesites (in part Jurassic) and altered peridotite and serpen-
tine all of which have been subjected to great compressive stresses or
hydrothermal alteration along the distinct overthrust fault zone which
has given access to mineralizing solutions from deep-seated sources
(probably granitic batholiths) at the time of the great batholithic
invasion of the upper crust when the Sierra Nevada were formed, in
Cretaceous time. The term lode is particularly applicable to this vein
system as most of the mines show two or three practically parallel
veins, often with subordinate spurs, all occurring within generally
definite walls, but with no vein traceable as a rule for any great length
on the strike. See Plate I (in pocket).
History
According to J. T. Wheeler, who was one of the original locators of
the Granite State claim, quartz mining history on the Mother Lode
in Amador County began with the location of the Original Amador
Company's claims by Thomas Rickey on the north side of Amador
Creek, followed by the location of the Spring Hill Mine on the south
side of the same stream by two preachers named Herbert and Davidson.
The location of the Granite State Company's and Pleasant Ridge
Company's claims came next. At that time the size allowed by miners*
rules for an individual's claim was 120 feet long by 60 feet wide.
These locations were made in 1850 ; gold quartz had been found and
worked in Mariposa County in 1849. Mexican arrastres were used
for several months to crush selected ore, which, in the case of the
Granite State, Wheeler reported as yielding $100 a ton. Several
MOTHER LODE GOLD BELT U
localities claim the honor of having the first stamp mill; in Mariposa
County the Mariposa Mine had one in 1849 and in Amador County
apparently the first was at the Spring Hill followed closely by an.
improved one of 12 stamps at the Granite State, for which the six
owners gave a one-half interest in the mine in 1851. Mining had
begun also on the lode in other counties in 1850.
In several localities the mining conditions were substantially
similar, and the same evolution of mining and milling methods went
forward. Mexicans built hundreds of arrastres which were used to
crush selected ore, notably at Nashville and at the Union Mine in
El Dorado County and at Carson Hill, Calaveras County. The amount
of such bonanza ores was limited and the process was too slow and
expensive to suit the Americans. With 150,000 white miners in the
gold regions in the early 1850 's, it is only natural that the crude
stamp-mill known in the southern Appalachians should have been
introduced in the different counties of the gold belt from Nevada
County southward to Mariposa almost simultaneously. The first crude
mills with wooden stems had much greater capacity than arrastres,
but were in general failures. With few exceptions the quartz mines
went into eclipse after a few years. The exceptions were those which
had ores rich enough to pay with then-existing high costs, from $7.50
to $15 a ton.
One well-known engineer has stated his opinion that claims on the
lode without ore-shoots outcropping at the surface are not likely to
make valuable mines. As a matter of fact, nearly all of the largest
and most profitable producers, including the mines at Angels Camp,
the Kennedy, Old Eureka, Keystone, Plymouth Consolidated, Raw-
hide and Princeton were not profitable until depths of 100 feet or more
had been reached, and many of them did not pay enough to keep
running until sinking had reached several hundred feet, as in the
case of the Utica. This mine and the Kennedy were worked inter-
mittently for over 30 years before becoming consistently payable.
The kernel of truth in the above-mentioned dictum is that a mine
known to have paid well at the surface may be expected to repeat at
lower levels ; but the examples quoted are enough to show that no claim
should be condemned solely for low surface assays.
The Mother Lode was a challenge to the courage and imagination
of the bolder pioneer miners who saw the shallow placers being rap-
idly depleted before 1855. After the first set-backs which were shared
alike by quartz miners at Grass Valley and on the Mother Lode,
these men set about solving the problem of profitably working low-
grade ores. The successful history of most of the Mother Lode mines
is wrapped up closely with the lives of a few sturdy individuals, hard
fighters and not too conscientious with those opposed to them, but
generally men of their word. Such men as Alvinza Hayward, Senator
Gwin, Colonel Nevills, C. D. Lane and W. F. Detert and their mine
foremen and superintendents have left a record for the profitable work-
ing of low-grade ores which will tax the capacities of modern mining
corporations to even approach. From 1865 to 1900 there were few
to oppose the quartz miner and little in the way of embarrassing laws to
hamper operation. On the other hand, the Mother Lode remained a
pioneer country until 1900 or later. There were no railroads. Water
10
INTRODUCTION
was freely available for power as long as the natural run-off lasted,
but provisions for storage were limited or absent so that most mines
had to close down from July or August until the first heavy rains,
usually in December. They could of course use steam for power
if grades of ore warranted, and many did, the last remaining steam
hoists having been displaced only about 15 years ago. Wagon roads
were abominable and became impassable with the first heavy rain
so that it was necessary to lay in during the dry season nearly a
year's supply of timber, powder, steel and other necessities. The
quartz mines of this lode were the trial ground for many of the new
processes, new machines and methods. The stamp-mill was steadily
enlarged from a weight of 200 or 250 pounds per stamp to 1250 or
1500 pounds each. Frue and Johnston vanners were introduced about
1870-1875 and remained standard equipment to the almost complete
exclusion of other concentrators as late as 1920. Dynamite was first
Index map, showing location of Mother Lode
used in 1868. This and the air drill had a great influence in increas-
ing tonnage, lowering gold content of mill-heads and necessitating
larger mill capacities. Electric power was first used for mine and
mill operation in California in 1890 at the Dalmatia Mine, El Dorado
County. Chlorination of sulphides was widely practiced until the
introduction of the cyanide process in 1896 ; and a few chlorination
plants were worked as late as 1915. Cyanide treatment was not as
widely used as might have been expected; there were difficulties in its
application to some ores, and the advent of railroads after 1900 and
the building of pyritic smelters at San Francisco Bay led to shipment
of much concentrate.
The cost of mine labor remained almost stationary on the Mother
Lode from about 1870 until the World War— $50 to $60 a month with
board in the early days became $2.25 to $3 a shift in later years as
mine boarding houses were dispensed with and men moved to hotels
in the nearby towns. The earlier miners were Americans for the
MOTHER LODE GOLD BELT 11
most part. Although Chinese miners were used in some drift placer
mines and for surface work at quartz mines, they never liked deep
quartz mining and did little of it. The Americans had been almost
entirely superseded by Austrians, Montenegrins, Italians and other
Southern Europeans before 1912. Up to the time of the late war, it
was not uncommon to see only five or six Americans in an under-
ground crew of 200 or more. The Europeans left during the war
and lately the underground crews of some of the larger mines are
mostly Mexicans.
Attendant conditions are now favorable for mining. Railways
run directly to the lode in several places, and practically every mine
is either on a lateral State highway or has a short road connecting
with one. Electric power is available within short distances for most
of the idle mines; all the active ones use it. Timber is abundant
usually within a short truck-haul; some operators use ''Oregon pine"
(Douglas fir) for shaft sets. Ample water for milling is available in
most sections. The elevation, ranging from 700 feet in southern
Tuolumne County to slightly over 1800 feet in El Dorado County
and 1932 feet at Mariposa insures fine climatic conditions, with only
a little snow at the higher elevations.
As regards size of operations, depths reached and gross and net
outputs, the mines of Amador County have been most important.
The quartz ores in the Mariposa slates have been the most profitable.
Vertical depths of a mile have been reached at the Kennedy and
Argonaut, with the workings still in this slate. At some other mines,
the ore channels have passed out of the slate at shallow depth into
the greenstone or hydrothermally altered schists. 'Schist ore' or
'gray ore' has been found at a depth as great as 4850 feet on the
dip but has not been mined to that depth. El Dorado and Mariposa
counties have also had their best Mother Lode mines in the Mariposa
slate, but depths less than one-half those in Amador have been reached.
Present operations in these counties are in few places over 1000 feet
deep. In Calaveras and Tuolumne counties the ores are almost entirely
'gray ore' or 'schist ore' though the Gwin Mine in northern Cala-
veras is in the typical Mariposa slate. The mines here range from a
few hundred to 4000 feet deep, but few have exceeded 3000 feet.
The World War, by increasing material and labor costs, put most
of the low-grade mines out of business. Just how serious this was,
will be indicated by the comparison of tonnage and value of ores for a
few years before and after the war. What may be called this state
of suspended animation in quartz mining continued until 1929. In
that year, gold production (which for some time had been coming
mostly from a few dredging companies and half a dozen of the larger
quartz mines) had dropped to only $8,526,703 the lowest for the
State since 1848, and not much more than one-third of the 1915
output. A revival of interest in gold mining was manifest in 1930,
and substantial improvement was indicated by an increase of nearly a
million dollars production that year. This rate of gain was held
during 1931 and 1932, in which latter year hand placer operations
of 'depression miners' were credited with one-half the increase.
The necessarily slower increase from quartz mining, due to the time
needed in opening or rehabilitating the mines or increasing operations
12 INTRODUCTION
in those alreadj^ producing, showed in 1933 even before the price of
gold was raised, in spite of recessions from other sources. The ten-
dency to treat lower grade ore partly offsets the effect of higher gold
price, so that added output is not a true index of increased activity.
Acknowledgment
The writer wishes to express appreciation of the courtesies
extended by the managers and superintendents of the mines visited
during the field work for this report. The other sources of informa-
tion drawn upon have been so numerous that it would be difficult to
give individual credit by footnote in every case, although the effort
has been made to list all pertinent publications in the bibliography.
The assistance received from the following men must be particularly
mentioned: A. V. Udell, president and Byron Rowe, general super-
intendent, Pacific Mining Company; the late James Richards and
J. C. Heald, for many years owners and operators of mines in El
Dorado County; J. A. Norden, manager, and S. P. Holt, superintend-
ent, Montezuma-Apex Mining Company; Wm. J. Loring, Robert J.
Duncan, and T. S. O'Brien; E. A. Stent, managing director and Alex
Ross, superintendent. Argonaut Mining Company ; Albion S. Howe and
James Spiers, former and present manager, respectively. Central
Eureka Mining Company: E. S. McCurdy and A. C. Wilson of Utica
Mining Company ; 0. A. McCraney, Stanley Arnot and A. D. Stevenot,
former Mother Lode mine superintendents; Phil Cox, superintendent.
Pine Tree and Josephine Mines, and James Kelly. Miss Helen M.
Gaylord and Victor C. Heikes of the U. S. Bureau of Mines gave
cordial assistance in obtaining gold production statistics and special
thanks are due to that Bureau and to them.
MOTHER LODE GOLD BELT 13
MINES
EL DORADO COUNTY
Introduction
While the Mother Lode follows the Mariposa slates through the
entire length of this county, there are marked variations in the char-
acters of the numerous gold deposits along it. In the southern part
of the county as far as the Church Union Mine on the north, the
veins occur in the Mariposa slate area and share many features with
the mines of Amador County. The slate belt is comparatively narrow
and is flanked on the west, and for some distance on the east, by the
diabase or amphibolite schist which seems to have had such an impor-
tant influence on Amador's mines. Topographically, the lode here
occupies a narrow stream valley for four miles where the North Fork
of Cosumnes River has forsaken its usual westward course to follow
the soft rocks.
Near the Church Union, a granitic intrusive has entered the foot-
wall of the slate, which changes its course to northeast and begins to
widen. From there north, the gold deposits are found largely in the
igneous rocks which have intruded the slates, or in the contacts. These
intrusives vary in character through the entire scale of increasing
basicity from granitic to ultra-basic dikes which latter have yielded ser-
pentine. The variations of these intrusiA^es and the increased width
of the Mariposa slate have given to the section a wider distribution
and a greater variety of gold deposits than anywhere else on the lode.
There are quartz veins in slate and schist, impregnations, dolomitic
veins, pocket veins and seam deposits.
^Mariposite and dolomitic rock are seen in mines near Placerville
and Kelsey, and bring to mind the mines on the lode in Tuolumne
County where serpentine is a wall rock. Beginning north of Placer-
ville is a type of deposit called 'seam diggings' where gold occurs in
quartz veinlets and seams in the decomposed schist of the greenstone
dike series and in places in the slate. The soft, rotten upper portions of
these deposits have been worked in many places, between Placerville and
the Middle Fork of American River. Beginning near Garden Valley, a
dike of amphibolite occupies the center of the Mariposa slate, which from
here northward is split into two branches, one running north through
Georgetown and Georgia Slide, the other northwest through Green-
wood and Spanish Dry Diggings. Mining of the * seam diggings ' by the
hydraulic process was carried on most actively near Garden Valley,
Greenwood and Georgia Slide.
Mining on the Mother Lode in El Dorado County has nowhere
reached such depths as in the counties to the south. The mines that
have been worked successfully to the greatest depths have been those
in the black Mariposa slate, as the Nashville, Montezuma, Church Union
and Springfield. In some other mines where wide deposits were
worked by open cut, probably the lowest operating costs for mining
14
EL DORADO COUNTY
and milling with white labor anywhere in California were achieved.
Electricity appears to have had its first application here to the opera-
tion of mining and milling machinery in California. Many of the
deposits in El Dorado County, in common with those of other counties
on the lode, have been low-grade, and there has been little done with
this type since 1915. But among the mines in the black slate are
many which have produced in the past ore comparable in value to that
taken from Amador's mines. Conditions unfavorable to gold mining
generally in recent years have perhaps been the principal reason
why the deeper levels of some of these mines have not been explored.
For fifteen years the mines of El Dorado County have remained
neglected by mining engineers and the better class of promoters. It
can not be denied that a prejudice has grown up, which appears to
be unwarranted, against the mines here. To this feeling must be added
the fact that records of many companies have been lost or were
destroyed in the San Francisco fire, so that tangible proofs of exact
conditions underground are usually lacking. As a final unfavorable
condition, it must be admitted that improper promotion methods and
inadequate financing have hurt some prospects.
The present year is witnessing the reopening of several of these
mines and there has been a resumption of prospecting all over the
county which has led to the bringing in of a few new producers.
Gold an
d Silver Production o1
El Dorado County, 1880-1933
Year
Gold,
value
Silver,
value
Year
Gold,
value
Silver,
value
1880
1881
$389,383
550,000
600,000
530,000
575,000
35,000
619,992
706,871
650,000
427,638
204,583
173,279
198,321
294,610
366,707
700,101
812,289
674,626
501,966
404,497
368,541
292,036
335,031
277,304
474,994
384,735
431,746
319,177
S208
900
1908-.
1909 -- -
342,033
238,284
171,304
133,967
105,565
62,688
133.886
401,288
361,821
24,758
28,352
30,121
13,379
34,109
47,340
30,264
28,207
40,212
91,789
82,254
122,017
57,680
78,019
85,322
182,043
540,939
5,504
1,299
1882
1910
1911
1912
1913
1914
967
1883
1,010
1884
1885
16,000
843
250
1886
1,822
365
500
408
275
359
654
1887-.
1888 .
1915
1916
1917
1918
1919..-
1920
1921
1922
1923 .---
1924
1925
1926
1927
1928
1929
1930
1,353
1,496
1889.
85
1890
1891
1892
722
279
155
1893
1894
1895
1896
1897
1898
1899
1900
1901
1,220
356
448
534
886
4,174
8,414
25,129
5,977
52
301
376
185
153
238
472
383
697
236
1902
250
1903
1931
283
1904
1932
438
1905
2,525
2,690
2,301
1933
1,458
Total value
1906-
1907
$15,766,078
$95,838
The natural conditions and the facilities available favor cheap
operation along the lode. A State highway traverses most of it,
passing within a short distance of nearly all the mines and good
branch roads are found everywhere. Electric power and water are
generally available nearby, and lumber and timber are produced in
MOTHER LODE GOLD BELT 15
abundance in the mountains which are within easy trucking distance
on the east. Placerville, Diamond Springs and Auburn are shipping
points on the Southern Pacific Railroad, from which supplies and
machinery can be delivered cheaply to the mines, the first two named
places being directly on the Mother Lode. Many experienced American
miners make their homes in the district, and the good roads permit
driving to and from work, so that in many cases camps do not have to
be maintained. Funds available can therefore be devoted almost
entirely to actual prospecting, with a minimum of the incidental, pre-
paratory and 'dead' work so necessary in remote sections.
Lode Mines
Adams GtUch Mine contains 40.68 acres two miles north of Nash-
ville in Sees. 25 and 26, T. 9 N., R. 10 E. It was developed through
adits by the former owner, J. C. Heald. Between 1902 and 1911 inclu-
sive, small lots of ore were hauled from this place to another mill
for crushing. The total yield during that time was $9,482.
The vein is reported to be about four feet wide in Mariposa slate.
The adits were 180 and 220 ft. long. Notliing is known to have been
done on the property since 1914. In 1931 it was one of several
mines leased to J. S. Rex Cole, but no new work has been started on it.
Adjuster Mine is on Martinez Creek a short distance above the
Union Mine. A crosscut adit was run years ago 250 ft. to the vein,
and short drifts followed the vein less than 100 ft. each way, north
and south. Both walls are Mariposa slate ; the vein is reported to
average 5 ft. wide, but could not be examined at time of visit, as the
adit was in bad shape. There is an old mill of 10 light stamps,
formerly operated by steam.
Alpine Mine in Sees. 15 and 16, T. 12 N., R. 10 E., is in the south-
erly part of the large amphibolite schist area which separates the
Mariposa slate into two belts in northern El Dorado County. It was
worked in the late 1860 's through an adit and ore was crushed in an
arrastre. By 1888, the Union Consolidated Company had reached a
depth of 140 ft. and was running a 10-stamp mill. From then until
1902, the shaft was deepened to 300 ft. The vein was reached by
crosscuts at 200-ft. and 300-ft. levels. Production stopped, so far as
available records show, in 1902 when an output of $6,800 was reported.
Some 10 or 12 years later the shaft was extended to 400 ft. in depth,
and drifts were extended south on the vein or parallel to it on the three
levels at 200, 300 and 400 ft. From a map, it appears that about 600
ft. in length was explored on the 200-ft. level; about 456 ft. on the
300-ft. level, and 475 ft. on 400-ft. level, with several hundred feet of
crosscuts.
In 1933, this mine was taken over by Pacific Mining Company.
Their work has been done on the 200-ft. and 300-ft. levels. The main
vein, striking northwest and dipping 60° to 65° NE., was found to
have been crossed by a series of faults dipping 25° S. According to
Byron Rowe, general superintendent, three ore-shoots, each about 100
ft. long horizontally and up to 30 ft. thick have so far been found at
these intersections. Former operators, who failed to appreciate the
16
EL DORADO COUNTY
MOTHER LODE GOLD BELT 17
geologic conditions, ran drifts through these ore-shoots but in raising
soon passed out of the fiat-lying orebodies. Although the ore-shoots
show a length of 100 ft. on the levels because of the flat pitch, the stope
length is about 30 ft. The vein has two strands, most of the work
being on the footwall section and to the south of the shaft. In 1934
a crew of 16 men w^as producing 75 tons a day. Ore is hauled by truck
to the Beebe mill at Georgetow'n. It is white, sugary quartz with only
about one-half of one per cent of sulphides. A mining cost of $2.19 a
ton was reported early in 1934.
Argonaut Mine had a 10-stamp mill previous to 1890, but had
produced principally from pockets. It lay idle thereafter until 1921.
when it was made the subject of a questionable promotion called
Golden Unit Mining Company. A Gibson mill was installed and a
few tons of rock crushed is alleged to have yielded a little gold which
was used to promote sale of units. No important new w^ork was done.
Later, in 1927, it was again the subject of a promotion, and 60 tons
of low-grade rock was milled. In 1928, a small tonnage of rock yielded
about $15 a ton.
The workings have been superficial, consisting of an adit 405
feet long giving a depth of 171 feet from the apex at time of last visit.
The vein was exposed for a length of 110 feet and the face at the time
Avas in amphibolite schist.
Beebe Mine is on a town lot at the north side of Georgetown;
other land under agricultural patent, the Woodside, the Eureka and
Eureka mill site claims adjoin and all are being operated by Pacific
Mining Company, A. V. Udell, president, Crocker Building, San Fran-
cisco.
The Beebe was prospected about 1917 by Bulkley Wells to a
depth of 250 ft. but remained unworked thereafter until 1931, when
Alexander Wise took it over. Beebe Gold Mining Company, a Nevada
corporation, was formed and a plant was erected containing two Had-
sell mills and eyaniding equipment. Mining had been, goifig on only
a .short time when Wise died and the property was shortly after taken
over hy the present operators.
The Beebe vein is a silicified and mineralized zone averaging 25
ft. wide but having a maximum width of 50 ft., in amphibolite
schist. It appears to be very similar to the 'gray ore' of Amador.
On the footwall of the ore zone there is a dike 10 inches to 2 ft. wide.
There is reported to be only a commercial hanging wall, gold content
gradually decreasing in that direction. The ore shoot was reported to
have been opened for 600 ft. in length in June, 1934.
The Eureka vein is producing a somewhat higher average grade
of ore than the latter. The Eureka claim was opened in early days
and some work was done at intervals until 1908. The deeper shaft
was sunk 235 or 240 ft. Levels called 85-ft. and 200-ft. levels were
turned, and on the latter short drifts were run north and south.
Another old shaft is reported 180 ft. deep. The present operators
have extended the Beebe 250-ft. level under the Eureka and have sunk
a winze to the 500-ft. level on the Eureka vein, and are drifting back
from there to the Beebe vein. Ore had been stoped previously in the
2—4156
18
EL DORADO COUNTY
Eureka to 130 ft. in depth but the output from this is not definitely
known.
The Woodside claim in Georgetown was a producer of specimen
ore in early days. It was opened to ai depth of 210 ft. In 1867 it had
Open cut, Beebe Mine, Georgetown.
Photo by C. A. Logan.
a 5-stamp mill and had produced considerable 'high grade,' one
wheelbarrow load of which was said to have yielded $12,000. By
1866 at a depth of 110 ft. the ore was showing so much sulphide that
the owner had invented a concentrator made of "a sheet of India-
rubber cloth 22 inches wide and about 8 feet long, sewed together at
MOTHER LODE GOLD BELT 19
the ends and stretched over two wooden rollers four inches in diameter
and three feet apart." This was mounted with one end three inches
higher than the other, was supplied with water through a pipe per-
forated with small holes, and dumped the sulphides into a box after
passing the upper roller. Perhaps it was the parent of the vanners
later used in such numbers. The only essential difference appears to
be the lack of a shaking motion.
Considerable water was reported in the Woodside workings and
this was giA'en as the main reason for stopping work. Nothing has
been done there in late years. The vein is reported to be two to three
ft. wide, in slate, and to carry over $3 a ton in free gold, besides an
unknown amount in the sulphide.
The Beebe mill, illustrated and described under Metallurgy (post)
is of interest. A crew of about 45 men was employed at the Beebe
and Eureka mines in June, 1934. and were producing and milling 325
tons a day or 7 tons per man-shift. This high efficiency results in a
low mining cost, reported at $1.17 a ton early in 1934. This included
overhead and general expense. The Beebe ore is a low grade, high-
sulphide ore (see under Metallurgy) and only efficient and economical
practice permits working it.
Big Chunk patented claim is one-half mile east of Kelsey on one of
the veins in the hanging wall of the Mother Lode. It took its name
from a large piece of 'specimen' quartz which contained $28,000 in
gold and which was found in placer mining the bed of Big Chunk
Eavine, a branch of Texas Ravine. This gold was supposed to have
come from the Big Chunk vein at the head of the gulch. This vein
has a width of about three feet at the surface and is of bluish quartz.
It has been worked to a depth of 100 ft. by a shaft, and has an adit
150 ft. long, both caved. It produced a number of pockets beside the
one mentioned.
Big Four joins the Isabel on the east and contains 16 acres in a
nearly square piece covered by agricultural patent.
A vein which is 30 inches wide at the collar of the shaft, outcrops
in the black IMariposa slate and strikes N. 10° W., dipping 55° E.
A shaft has been sunk 96 ft. on the vein, \\ith drifts 50 ft. long in
each direction at the 50-ft. level, where an ore-shoot 75 ft. long is
claimed. Forty tons of ore was reported to have yielded $10 a ton in
free gold, and another lot of 50 tons produced $13 a ton, not including
sulphides, regarding the amount and value of which nothing is known.
Big Sandy Mine is at Kelsey and is one claim 300 ft. by 1500 ft.,
patented. Grey Eagle claim adjoins on the north.
The claims are of historical interest, having been located by James
W. Marshall when he moved to Kelsey. He did considerable work,
especially on the Grey Eagle where he ran an adit which is still open.
The Big Sandy claim was a producer of low-grade ore for several
years but lately has been worked only for pocket gold which has been
produced by James Kelly, lessee. Occasionally very beautifully crys-
tallized gold specimens are found. They resemble those taken out in
Placer County near Forest Hill and at the R^d Ledge i\Iine near Wash-
ington, Nevada County.
20
EL DORADO COUNTY
The low-grade ore was worked in an open cut 750 ft. long, 25 ft,
to 30 ft. deep and 8 ft. to 15 ft. wide. James Kellj^, former superin-
tendent, states the ore averaged $1.75 to $2.25 a ton, in free gold and
that about $66,000 was produced. A vertical shaft was sunk 340 ft.
which cut the footwall vein of the Mother Lode at 240 ft. and again in
the bottom, as the vein stands nearly vertical. On the 60-ft. level, a
crosscut was run 60 ft. west and drifts were run 50 ft. north and 60
ft. south. On the 120-ft. level, the crosscut is 40 ft. long with drifts
15 ft. north and 80 ft. south. A rich stringer was found and a winze
was sunk 40 ft. on it, when it was lost. Aside from this, the ore was
low grade. The bottom of the shaft is said to be in ankerite two to
three feet wide. On the surface near shaft, the footwall rock is an
amphibolite schist dike, and the section across the claim shows in order
going east, bands of porphyry (altered, obscure) soapstone and
ankerite, talcose schist, vein matter 15 ft. wide composed of stringer
leads of quartz and carbonates in altered schist, and Mariposa slate
50 ft. wide. The hanging wall of the vein has not been explored, but
on the Harlow claim, 600 ft. east, there is a vein which has been
slightly prospected.
The specimen gold lately produced came from surface workings
south of the shaft, in seams crossing a thoroughly altered rock evidently
a dike.
Black Oak 3Iine in the NE14 of Sec. 34, T. 12 N., R. 10 E., near
Garden Valley school, is; one of the small mines which has been paying
well during the past year. Previously it had been worked only as a
pocket mine and had produced little. Edwin W. and Russell J. Wilson,
a partnership, have recently been employing 18 to 20 men and have
met with success after only a short period of operation and a moderate
investment. It is a good example of how chance figures in mining.
Neither partner had previoiLs mining experience, and the property lies
in a district peopled largely by pocket-hunters.
The amphibolite schist in which the deposit occurs is the southerly
end of the large lens containing the Alpine Mine, which lies two
miles north. Here the schist has narrowed to a width of only a few
hundred feet. The vein and the schistosity of the schist both strike
N. 20° W. and dip steeply northeast, the vein forming small quartz
lenses up to 3 ft. wide. At the time of "\dsit late in June, 1934, work
was being done at a depth of 55 ft. Here the writer noted that a
mud slip or bedding plane in the schist crosses the vein, striking N. 53°
W. and dipping 37° NE. This mud slip is only one to three inches
thick but it appears to have been the principal agent in localizing the
deposition of gold. A length of 50 ft. along the strike of vein had
been worked at the time, and the operators reported that the gold had
been taken entirely from a depth of about three ft. directh^ under the
slip. Still in the zone of surface oxidation, the ore carried mossy
concentrations of free gold, at times rich enough for recovery by
hand ; some ore rich enough to ship to a smelter, and more of milling
grade which was being trucked to the Hart mill near by for crushing.
The mill ore varied from 2 to 10 ft. wide, extending into the schist walls
on each side of quartz. This claim contains seven acres and the plant
is very simple, with a small hoist, shop and compressor.
MOTHER LODE GOLD BELT 21
The same operators have a lease on the Davenport property con-
taining 320 acres immediately south. The amphibolite schist traverses
this land which contains a deposit similar to that at the Hart Mine
(which see, post, under Seam Mines). In previous operations a series
of open cuts and a crosscut 280 ft. long had been run. In the crosscut
Russell Wilson reports that a width of 30 ft. gives assays high enough to
permit mining at present. A width of 5 ft. was stoped 90 ft. long by
40 ft. high and is said to have yielded a fair return. A shaft was
being sunk to further prospect the deposit in 1934.
Blue Lead claim joins the Big Four on the south and the Isabel on
the east. At an early date, previous to 1867, this claim was opened to
a depth of 250 ft. and an unknown amount of drifting was done. A
20-stamp mill was erected and a total outlay of $250,000 was said to
have been made. The large dump indicates that the work must have
been done entirely in the black Mariposa slate, with a large proportion
of waste compared to the amount of ore handled. Although the work-
ings yielded some fine specimens, it is said operations did not pay, and
work had ceased before 1868.
Chaparral or Golden Queen claim, two miles southwest of Kelsey,
was discovered in 1872 by Willets. From then until 1875 the property
had a mill and was a small producer of ore reported to have yielded
from $7 to $15 a ton. By 1875 the shaft, which had been sunk on the
middle vein, was 150 ft. deep. The company then operating the mine
was also trying to work the Gopher-Boulder mine but evidently lacked
funds to carry on any new development. After taking out such ore
as was available, they quit both properties. In 1901, the Golden Queen
Mining Company was formed, but apparently did very little work on
the mine. The shaft finally reached 200 ft. in depth.
The west vein on this claim has been only slightly prospected.
"Where it was mined, the middle vein was reported two to four feet
wide. In depth, the footwall is said to be slate and hanging wall
diorite ; but workings have been inaccessible for years. It has been
estimated that a lower adit 820 ft. long would tap the ore 195 ft. below
the bottom of the old shaft. This distance might possibly be shortened
because of the southward rake of the ore-shoot.
Church Mine (El Dorado or Church Union) was worked as a quartz
mine first in 1886 and was 500 ft. deep in 1887. The ore-shoot was rich
but not long, and the period of principal operations was about 13 years.
Records of the company, like those of so many others, are said to have
been destroyed in the San Francisco fire in 1906.
The principal work and production was from the middle or
'kidney' vein. In July, 1890, the ore is stated to have averaged $8 to
$9 a ton in the 10-stamp mill ; in August, $13 ; and in September, better
than that, exclusive of sulphides. In 1894, a new 10-stamp mill was
built which had a duty of 20 tons in 24 hours. The mine is in the
Mariposa clay-slate.
The following notes are from a statement made to the writer by
James Richards, who was superintendent of the mine for many years.
There are no maps nor other exact details available.
"The main shaft was vertical and was 1200 ft. deep, in the foot-
wall below 400-ft. level. There was a poor place in the mine between
22 EL DORADO COUNTY
350 and 500 ft., where the ledge cut out and we had only the gouge,
then ore came in again. The vein below this averaged six feet wide,
with the rich ore in the middle. The 600-ft. and 1200-ft. levels were
run clear to the propertj^ line. The crosscut from shaft to vein on the
1200-ft. level was 670 ft. long and from this level we sank a winze on
the vein to the 1400-ft. level. The ore milled dovm. as far as the 1300-ft.
level had averaged $17 a ton. At 1300-ft. the gouge came in, five to
six feet wide; the ledge became so soft and broken that it could be
shoveled. It carried about $4' a ton here. On the 1400-ft. level, we
drifted 80 ft. The ground ran and swelled over night so that it could
not be held with tight lagging. There was gouge on both walls.
"There was a great d^eal of $2 to $3 rock in the mine that should
have been mixed with the rich ore to give a mill feed worth $6 to $7
a ton. ' '
Sulphides formed 1|% to 2^% of ore and assayed up to $140 a ton.
The quartz made in lenses or kidneys up to 250 ft. long, but the best
ore was said to be a chimney about 75 ft. long. To a depth of 300 ft.,
the mine made about 20,000 gallons of water in 24 hours, and later
made 75,000 gallons daily when opened to 1350 ft.
It is the opinion of the present owner that the orebodies in both
the Church mine and the Union or Springfield, were formed at the
points where a side vein called the Klondike left the main lode wall
and returned to it.
The east vein was worked in the Union (Springfield) mine just
south of the Church. From different levels in the Church, prospecting
was done on the west vein by running crosscuts during the operations
described above. The mine was unwatered in 1900-1901 with the idea
of checking up on the reported results of that previous work. There
is no information regarding what was found, but work was not con-
tinued. The west vein, however, is known to be quite low grade.
Bihliographv : Cal. State Min. Bur. VIII, p. 191; X, p. 171;
XII, p. 106 ; XIII, p. 137.
Cincinnati Mine, four miles north of Kelsej^, covers a stringer lead
deposit in a decomposed dike in the INIariposa slate ; it is not certain
that the open cut from which the last rock was milled previous to time
of visit in March, 1932, had reached the hanging w^all, though a
width of 10 feet had been cut. Older open cuts and shallow shafts
extend south along the vein probably 600 ft. to the propertj^ line.
No record remains of the results of earlier work. In 1917 the
claim was equipped with a light 5-stamp mill and the first clean-up
early in 1918 is reported to have given an average return of $3.82
a ton by amalgamation alone. Later tests have given better results but
no recent production has been reported.
Coe Hill Mine {Gold Star or Bathurst) is a mile south of Garden
Valley. Shallow shafts have been sunk on several veins. Late in
1921, A. Tetrault and associates milled 50 tons from a dump and from
an adit, which is reported to have plated $7 a ton. In 1925, Ed
Bathurst, the owner, reported production of some $6 ore, and the next
year a smaller lot of much higher grade, containing over an ounce of
gold per ton. Since then, there has been no record of production.
MOTHER LODE GOLD BELT 23
A small 2-stainp mill was formerly operated. This property adjoins
the Oro Fino.
Crown Point and Gold Queeyi Consolidated. These two patented
claims cover 3000 ft. in length and 600 ft. in width along the Mariposa
slate 2^ miles from Diamond Springs.
The Crown Point has a shaft 500 ft. deep which is intersected at
a depth of 300 ft. by a drain tunnel 600 ft. long. The 400-ft. level was
run 250 ft. along the east vein of the Mother Lode. This vein was 8
to 20 ft. wide. A crosscut was run from this level westward through
the schist for 60 ft. to the west vein, which showed a thickness of 7 ft. ;
it was followed 50 ft. by drifting. Mill tests of quartz from both these
veins are reported to have been satisfactory; but there is no written
record of them available.
Another shaft was sunk 150 ft. south of the first, to a depth of
150 ft. Here the ore was reported in small lenses. Several small lots
are said to have jdelded $20 a ton or more. All of this work was done
near the north end of the propert3^ About 1000 ft. south some shallow
shafts, tunnels and trenches have been run in search of pockets.
Dalmatia Mine, east of Kelsey on the hanging-wall side of the
Mother Lode, has the distinction of being the first mine in California
to employ electric power for the operation of mining and milling
machinery. Hydroelectric power generated on Rock Creek was sent
to the mine over a line one mile long and was first used in February,
1890, to run Huntington mills and other equipment.
The property before that had been known as the Kelly mine and a
shaft had been sunk 260 ft. upon a vein two feet wide, crossing the
main seam belt lode at an acute angle and producing ore which is
said to have yielded $16 a ton. After the sale of the mine to an English
company the preparations for working the low-grade orebody began
with the driving of an adit 1200 ft. long to furnish an outlet for ore to
be mined in a glory-hole above. AVhile this adit was being run, a
flat or 'blanket' seam was struck from which $14,000 in pocket gold
was taken in two days. The main low-grade orebody was later mined
by open pit, dropping ore through raises to the adit level, and crushing
in Huntington mills.
Two miners working on contract mined the ore at a cost of only
7^ cents a ton as it was soft and very easily broken. It is believed
that the cost of mining and milling here, which is claimed to have been
only 43 cents to 56 cents a ton, set a low record that has not been sur-
passed in California. These operations extended from 1890 to 1894.
An open cut about 500 ft. long averaging about 40 ft. wide and 80
ft. or more in depth was made. The gold occurred free in the seams
and quartz stringers in the rotten amphibolite schist characteristic of
the seam belt.
Esperanza (Garden Valley) Claim is one mile northwest of Garden
Valley on a narrow dike of amphibolite schist altered from igneous
rock that intruded the Mariposa slate or was contemporaneous with it.
In 1890 the claim was being developed and was supposed to have a
deposit of low-grade ore. A 20-stamp mill was erected and a sale made
later to an English company. In 1898, after the shaft had been sunk
24 EL DORADO COUNTY
600 ft. vertically and 700 ft. of drifts had been run, this company
crushed about 1000 tons of rock. Thereafter, they quit work and
sold the machinery in 1900.
Falls Mine. Jos. Drechsler, owner. It is in the NE^ of Sec. 1,
T. 9 N., R. 10 E., mineral survey 5815. An adit has been run 235 ft.
and the OM^ner has been sluicing the surface to find the vein from which
gold has come.
Golden Gate (McNulty or Oakland) Mine. This comprises two
patented quartz claims and 40 acres of patented placer ground. It
is reached from El Dorado and lies just south of the Springfield mine.
This was one of the older mines, having been located about 1852
by W. J. McNulty and having been worked before that by Spaniards
and Mexicans using arrastres. It was formerly known as the McNulty.
On the claim of that name a tunnel was run about 300 ft. to the vein
giving backs of 200 ft. on the middle vein, and having been continued
from there as a crosscut for 300 ft. farther in the direction of the
east vein, which here shows immense outcrops on the surface. The
tunnel was never completed as far as the east vein and it would be
necessary to run it about 200 ft. farther to reach that vein. It is
estimated that if this were done there would be about 500 ft. of backs
above the tunnel on the east vein. Where this tunnel struck the middle
vein an internal shaft was started and was sunk to a depth of 600 ft.
Most of the ore was stoped out from this shaft below the tunnel for a
length of about 300 ft. According to James Richards, who was formerly
engineer of the property, this ore averaged $15 a ton in a 10-stamp
mill then located on the mine. This vein had an average thickness
of ^ ft.
On the St. Louis mine, which lies east of the McNulty, the only
work done has been three or four small shafts which show the east
vein to have a width of from 8 to 12 ft. with assay values reported to
run from $4 to $8 a ton. This was the vein toward which the tunnel
from the McNulty was run.
Goplier-Boulder Mine is a mile and a half north-northwest of
Kelsey and covered 3611 ft. in length along the lode as originally
surveyed.
The Gopher mine proper w^as worked in 1858 when it produced
$15,600 but the mill was removed before 1868. Ore was mined in two
open pits and dropped through raises to a lower adit. Ore averaged
$2.50 a ton and made in flat quartz stringers making into the main
lode with a low dip to east. The open pits were 40 ft. wide. The upper
tunnel followed a vein four feet wide for about 200 ft. This also
was worked at an early date for a length of 120 ft. and 100 feet high and
is supposed to have been rich, as pillars assayed $16 a ton. A lower
tunnel 850 ft. long has a drift 150 ft. northwest on a vein four to five
feet wide which has been stoped in places. A drift northwest struck
and followed a flat vein of 'ribbon quartz' for 100 ft. It assayed $2
a ton for 50 ft. and $3.50 a ton for 50 ft.
A transverse gully crossing the line of the lode between the
Gopher and Boulder workings indicates a fault, and this is confirmed
by the relative positions of the workings which are on the hanging-
wall side in the Gopher and on the footwall in the Boulder. The
Gopher vein strikes N. 23° W. and the Boulder N. 11° W.
MOTHER LODE GOLD BELT 25
The Boulder vein is a large 'bull quartz' outcrop, 50 ft. wide at
the Boulder shaft and in green amphibolite schist, showing mariposite.
The shaft is an incline on an angle of 35°, 260 feet deep starting in
the hanging wall, but the best pay was found near the footwall.
Levels were run at 50-ft. intervals but no stopiug was done below
the 100-ft. level. The ore shoot was followed 130 ft. north and 120
ft. south from the shaft and was mined 7 ft. wide. Old records indicate
it paid $6 a ton in free gold and show a production of $40,000 from
it. On the 200-ft. level the ore shoot was lost, but 43 ft. north of the
shaft ore assayed $3.10 and was followed 42 ft. and is said to have
improved up to the face. In the 250-ft. level north the ledge was cut
35 ft. from the shaft on the footwall and is said to assay $3.30 a ton
for a width of 7 ft. On the south in the 200-ft. level the ledge was cut
but not followed, and on the 250-ft. level it appeared that the ore was
pitching north.
Most of the work was done on the property before 1900, and ore
was cheaply mined, and milled with 20 stamps and two Huntington
mills. The company also operated the Dalmatia (which see) and was
the first user of electric power to run mine machinery in the State.
In April, 1931, F. "W. Grosjean had an option on the property
and did some prospecting work on the surface, milling some low-grade
schist in an old Huntington mill. Only the fine decomposed material
was worked. The venture was short-lived.
Griffith Consolidated includes the Griffith and Bryant which is
2999 ft. long and 600 ft. wide and several other unpatented quartz
claims giving the total length of about 4500 ft. along the course of the
Mother Lode. The claims are a half mile southeast of Diamond Springs.
Most of the work has been done upon the Griffith and Bryant
which formerly consisted of two claims. At the time of the original
discovery a small shoot of very rich ore was taken from near the surface
of the Bryant claim. This ground was worked in a small way for quite
a long period during which time several shallow shafts and tunnels
were run. The work begun by Griffith and Bryant in the fifties had
been carried down to a depth of only 150 ft. when the Jumper Syndi-
cate took the property about 1896. They sank the Griffith shaft to a
depth of 700 ft. At the 350-ft. level the vein was 5 ft. wide and is
said to have milled $8 a ton. The company was no doubt too hasty in
putting a mill and other expensive equipment on the property before
it had been well prospected. After fully equipping the claims and
putting in electric power they continued sinking. At 500 ft. the vein
was 12 ft. wide and was running with the schistosity of the slate.
Under such conditions it was difficult to obtain clean ore and the ore
taken out at that level was said to go $4.50 a ton or less on account of
the large amount of wall rock jarred do^\Ti by the heavy drills and
blasts. The ore there contained about 3% of sulphides which assayed
$36 a ton in gold. On the 350- and 500-ft. levels the work was done
mostly north of the shaft prospecting a length of nearly 500 ft. along
the vein.
The shaft was continued to the 700-ft. level and on that level on
the north end it is stated that conditions began to improve as the vein
began to cut at a slight angle across the schistosity of the slate and the
walls hardened. When the 700-ft. level was reached an order was given
26
EL DORADO COUNTY
by the company to mine 2000 tons of ore and mill tests of this ore,
according to the former superintendent, went $4.25 on the plates and
3% sulphides worth $42 a ton. The company closed the mine shortly
thereafter and nothing has been done in those workings since.
About 1000 ft. north of this shaft the Klondike shaft has been
sunk 150 ft. It is tapped at a depth of 100 ft. by the Klondike tunnel
which is 300 ft. long and ^vhich follows the vein. The vein here shows
in the form of small lenses from one foot to four feet in thickness. Two
or three lots of ore from these workings milled from $20 to $65 a ton.
A lot of about 100 tons taken out in 1903 is reported to have yielded
$32 a ton, but there is no written record of this.
About 1200 ft. south of the Grifath shaft, No. 2 shaft was sunk
253 ft. In the bottom of this shaft it is said that the rock still assays
well but is broken into stringers and frozen to the walls.
Harmon Group includes the Van Hooker, Young Harmon, Old
Harmon, Gross No. 1 and No. 2 and Eureka patented claims on the
Mother Lode just north of Placerville.
The work at time of visit was mostly on the Van Hooker claim,
where an old adit was reopened and extended, having a total length of
1200 ft. from portal to north face at time of visit, and giving a vertical
depth of 200 ft. on the vein. The ore occurs as a stringer lead and
lenses of quartz in Mariposa clay slate, both having been greatly
crushed by movement along the course of the vein, which has a wadth
of from 2 to 12 ft. A pay shoot 50 ft. long had been stoped and raised
upon to a height of 80 ft. and for an average thickness of 5 ft., at time
of visit. The best ore shows pyrite, galena and coarse free gold. The
ore that had been milled up to that time had yielded $7.25 to $27 a
ton. Production began in 1928, and continued for three years.
Further prospecting has since been done on the north, where the
adit level was turned to follow the vein, but new orebodies had not been
found at time of last visit. A winze was also being sunk from adit
level late in 1931.
There is a mill of 10 light stamps and one concentrator, capacity
24 tons daily. Electric power is used to run the mill and air com-
pressor.
At the Old Harmon, a new collar was put on the shaft, which was
560 ft. deep in ,1931, preparatory to reopening it to 115 ft., where a
prospect was claimed. The mine produced considerable gold (some
estimates being as high as $250,000) during early operations. It
was worked between 1870 and 1890, ha^^ng been a part of the True
Consolidated Mining and Milling Company's holdings, which were
developed by a long adit in 1887 and 1888, running the length of the
Harmon claims. About 1895 these claims passed into the hands of
Placerville Gold Mining Company and little has been done on them
since. Nothing was done in 1931 below the surface.
The vein running through the Old Harmon and Young Harmon
claims averages 15 ft. wide and in places is 45 ft. to 70 ft. wide,
occurring as stringers in slate.
BihliograpMj : Calif. St. Min. Bur. R. VIII, pp. 180-191;
XII, p. 125.
MOTHER LODE GOLD BELT 27
Havilah (Nashville) Mine, at Nashville is said by early authors
to have been the first quartz mine worked in California; but else-
where^ it is stated that it was the first one worked in El Dorado
County (1851), and is credited with an output of $150,000 from sur-
face and shallow ore, first worked in arrastres. ''The first systematic
work" was done in 1868 and the same authority states that "in three
vears the mine paid for all of its development work, and plant costing
$100,000 and paid $50,000 dividends" from ore yielding $3 to $15
a ton. Litigation closed it in 1871 ; Joshua Hendy obtained a patent
in 1880 and by 1882 had sunk the shaft to a depth of 642 ft., the
ore from the last 100 ft. of shaft being reported as yielding an
average of $8.50 a ton. After producing $45,500 the Hendy interests
quit. The mine then lay idle until 1894, when a 20-stamp mill Avas
erected and during 1895 and ,1896, G. E. Williams and Hendj^ pro-
duced $20,000 from ore mined between the 500-ft. and 600-ft. levels.
No further work was done until 1903. Between then and August,
1906, the shaft was sunk to the 1200 ft. level with drifts 500 ft. south
and 1285 ft. north from the shaft crosscut on that level. The north
drift explored the vein under the Montezuma IMine, where a short
ore-shoot was found. At that time it was equipped with a good plant
including a 20-stamp mill. The only production figures at hand for
this period were for 1904, when the shaft was 1000 ft. deep, and when
4000 tons yielded $15,325. If there was production in 1905 and 1906,
the separate figures for this mine are not available as it was being
operated jointly with the Montezuma, and the later work through the
Havilah shaft was in the Montezuma. Although the mine was under
option in 19,13-1914 with the Montezuma, no further work was done
until the present year, except the milling of part of the dump, which
yielded $2 a ton or more. At present, the property is being reopened
by Montezuma-Apex Mining Company, who are also operating the
Montezuma Mine, adjoining on the north. The Havilah shaft has been
reopened and during the past . summer the milling of ore from the
upper levels was started.
Geologically, the Havilah is similar to the Montezuma, with the
same vein in black Mariposa slate walls. The maximum width of vein
is 20 ft. but it averages about 5 ft. wide, and in the new work on the
200-ft. level was being mined 6 ft. M'ide in June, 1934. The former
operators had stoped for a length of 100 ft. there on the south side of
the shaft. The present company was carr^dng on stoping there in
June for an additional length of 80 ft.
Hines-Gilhert Mine is 20 miles from Auburn via Spanish Dry
Diggings, the last mile being steep trail. The five claims lie partly in
El Dorado and partly in Placer County in the steep canyon of Middle
Fork of American River, but recent, work has been in El Dorado
County.
Two veins occur between Mariposa slate and amphibolite schist,
where the slate belt is split by intrusives or interlayered extrusives.
The slate bodies here are comparatively small. The hanging-wall vein
has been traced about 400 feet on the surface. It strikes N. 20° W. and
dips 80° NE. The development work on it consists of short adits and
^California Mines and Minerals: Cal. Miners' Assoc, 1899, p. 310.
28 EL DORADO COUNTY
open-cuts, mostly superficial. This vein averages five to six feet wide
and the unoxidized ore is reported to assay well. A crosscut was run
to the footwall vein from near the river level, but this had caved and
was inaccessible at time of visit. The veins are about 200 ft. apart.
By 1924, one adit had been driven 450 ft. giving a depth of 110
ft., and small tonnages of good-grade ore were produced annually
from 1921 to 1924 inclusive. In 1925, ore was low grade, but in 1928
improved again. Since then there has been no production. The output
since 1921, less than 2000 tons in all, has varied from $3 to $40 a ton
recovered.
The property has a 10-stamp mill, a 3-drill compressor, etc.,
operated by water power, using water from Canyon Creek, under
600 ft. fall. Work was resumed in 1934.
Ida Livingstone patented claim one mile north of Kelsey has a
vein striking N. 50° E. and dipping 80° east at the main shaft,
between hard slate walls. For a distance of about 400 ft. on the north
end, the vein outcrops as a solid body of white quartz reaching a
width of 25 ft. or more, and with little sign of mineralization. An
old shaft on the north is of unknown depth, probably less than 100 ft.
The south or main shaft was 150 ft. deep, in the creek where water
caused trouble. An ore shoot 50 ft. long on top tapered to a length
of 10 ft. and thickness of only six inches at the bottom. It paid $26
a ton in a custom mill.
Isabel claim in the Garden Valley district, is traversed by a vein
striking N. 30° W. to N. 45° W. and from 2 ft. to 8 ft. or more in
width. The vein w^as worked to only a few feet in depth for a length
of several hundred feet, and rock was crushed in arrastres at first and
later in the mill on the Blue Lead, adjoining (which see). Reported
value of ore, $3 a ton on north end on hanging wall side. The vein is
in black slate in the shaft which was probably not over 30 ft. deep and
was the deepest working on the claim.
Joseph Skinner (Fisk) Mine adjoins the Lemon claim on the south.
It is one of several small claims known as seam mines and pocket pro-
ducers, and is on the east or hanging wall side of the main lode. The
dip of formations here is nearly vertical and steeply west, probably
due to hillside drag. In earlier days the surface was hydraulicked.
Later workings are reached through a cross-cut 90 feet deep at the
face, and running west 232 feet, from which drifting had progressed
76 feet north when visited. On the west of vein, a crosscut shows
ankerite to be at least 60 feet thick. Strips of altered gray dike-rock
alternate with the black Mariposa slate across the north face. On
the east side of fissure a dike 18 inches wide is succeeded by 6 inches of
slate full of pyrite ; the latter is followed by 11 inches of dike rock.
Gold was observed to occur in a quartz seam in the dike where the
quartz comes in contact with the lower (east) side of the slate. Three
men were taking out a little specimen ore when visited in 1932.
The Skinner and Lemon claims together M^ere credited with a
production of $80,000 before 1897 from a length of 1700 feet. In a
few months in 1897 and 1898 a further output of $10,000 was reported
from the claims, then known as the Empress Josephine Mine. Again,
in the period 1901-1903, nearlj^ $9,000 was produced. Most of the
yield was from specimen ore, though some small lots were milled.
MOTHER LODE GOLD BELT 29
Kelly Mine. Miss Margaret Kelly, owner. This prospect is on
the hanging wall side of the Mother Lode, on the Kelly Ranch one-
half mile north of Kelsey. It is in the Mariposa slate. A heavy vein
of quartz outcrops here.
Thirty years ago shallow shafts were sunk, probably in search of
pockets, but no ore was milled. In 1932, one shaft was cleaned out and
extended and another was sunk, both having depths of 50 ft. at time
of visit. They are 150 ft. apart, and both on the vein. In the north
shaft, vein is over 6 ft. wide, striking nearly due north while the
schistosity of slate strikes N. 15° W. In short drifts from the bottom
of south shaft, the vein increased from a width of six inches on the
north to four feet on the south in a distance of 33 ft. A flat seam of
quartz 10 inches wide enters here from the w^st, and may be connected
with the formation of ore. After favorable assays were had, a small
mill run was made, but results were vitiated by a mill accident, and
work has since been suspended. The gold is very fine, but the prospect
;!ppears to have some promise.
Kelsey Gold and Silver Mine is six miles north of Placerville and
was propected many years ago. Kelsey Mining Company, Incorpo-
rated, w^as formed in 1926 to reopen it. An old adit was cleared and
has since been extended, having a length at present of ,1700 feet, fol-
lowing the vein north to N. 32° W. Several footwall crosscuts have
also been run.
The claims, which extend for nearly a mile along the contact of
narrow dikes of amphibolite schist and serpentine with the enclosing
Mariposa slates, show the characteristic ankerite and grey schist ores
which appear everywhere on the Mother Lode w^here these formations
occur. A cross section of formations from west to east, shows a schist
footwall, six inches of mixed carbonates, 8 ft. of grey schist mineral-
ized with quartz, pyrite and galena, forming low-grade ore in places ;
then 6 ft. of slate 'ribbon rock,' containing much pyrite and some
galena ; and the black Mariposa slate hanging-wall. AVithin this lode
zone, the formations have been much disturbed by faulting. Another
section exposed by crosscuts shows a total width of 46 ft. with the
footwall and hanging wall veins as mentioned above.
The company put up a second-hand 10-stamp mill with two Wilfley
tablegi in 1928. Some oxidized 'gray ore' from the ankerite zone near
the adit portal yielded coarse free gold but this was in only small
amount. Beginning about 800 ft. from the adit portal, stoping was
carried on at intervals for a length of 320 ft. and to a height of 30
to 50 ft. above the adit. In the four years from 1928 to 1931, inclu-
sive, about 15,000 tons was crushed and yielded average returns from
$1.80 to $6.40 a ton. This was mostly from the footwall vein. During
the next two years, little work was done.
Early in 1934, C. T. Palladine became superintendent and activity
was resumed. In June, 20 men were employed. Numerous surface
improvements were made, including changes and additions in the
milling plant, which was altered to handle ore by flotation, retaining
the stamps for intermediate crushing. The flow sheet as it stood June
28, 1934, is illiLstrated under Metallurgy, post. Milling had not been
started at that time.
30 EL DORADO COUNTY
Larkin Mine, one mile east of Diamond Springs had been opened
to a depth of 250 ft. by 1896 and had three levels. It was a producer
until 1903, first having 5 stamps and later 10. The shaft was sunk
800 ft. vertically. The footwall is schist; the vein worked is in the
hanging wall of a wide ankerite vein or zone, similar to those so com-
mon in El Dorado and Tuolumne counties. The vein and accompany-
ing altered igneous rocks are in the Mariposa slate east of the great
intrusion of granitic rocks which here has displaced the slates so
that the veins strike north or northeast. The principal productive vein
was from 4 to 12 ft. wide, contained 11% of concentrate and the
meager figures available indicate a yield of $5 a ton in the later work.
A 'west vein' was prospected on the 400-ft. level and was reported
7 ft. wide. The total production was estimated by C. H. Dunton,
former superintendent, to have been about $125,000.
Lookout Mine, in the Mariposa slate one-half mile southwest of the
Union Mine, was located about 1860 and has been worked intermit-
tently in a small way since. It has been a small producer of gold
pockets. Since 1912, when a production of over $2,200 was reported,
there had been no recorded output until early in March, 1933, when
Arthur Seymour, lessee, reported a production of $15,000. The mine
has been worked through an adit over 600 feet long. Seymour reported
the strike was made in the roof of the adit, where a raise was started
520 feet from the portal, and 270 feet below the surface.
Lucky Marion Mine, a mile west of Greenwood, occupies part of
the contact of a dike of serpentine with the Calaveras formation. It
was worked in 1896 and 1897, and had an incline shaft 112 ft. deep
and a 20-stamp mill. From 1897 to September, 1899, it was shut down
on account of litigation. Thereafter, in 1901, it produced $3,860.
No tonnage figures are available, but the ore is believed to have been
'high-grade' from a greenish quartz stringer 18 inches to 2 ft. wide.
There is no further record of production.
Martinez Mines (formerly Hillside Group, with some later loca-
tions). The claims are on Martinez Creek, 4^ miles by road south-
east of El Dorado and south of the Union Mine. The workings are in
Mariposa slate east of the 'bull quartz' vein. Holdings cover 4500 ft.
in length on the strike.
Little work has been done on the claims since 1926. During that
year, a few men were working through a short adit, winze and drifts
reaching a depth of 86 ft. below the outcrop on Hillside No. 3 claim.
The slate there dips west and ore is found in small stringers, seams
and floors which lie nearly flat, with a slight dip west. Ore was
hoisted by hand in a small bucket and taken about one-half mile by
sled to a small 5-stamp mill beside the creek. The scanty water
supply in summer permits of milling only a few tons of ore at a time.
The returns from the small tonnages milled from 1923 to 1926 inclu-
sive varied widely, as might be expected, ranging from less than $4
to over $80 a ton.
In 1926 an adit was run 900 ft. into the lower part of the hill and
this adit would have to be extended 300 ft. further to be directly
under the workings first described. This would give 230 ft. greater
MOTHER LODE GOLD BELT 31
depth than that in 1926. There is a compressor and other equipment
at this adit.
At a distance of 700 ft. south of the recent work, an old adit
600 ft. long crosscuts the vein. Between the two, another crosscut
70 ft. long reveals low-grade quartz and is thought to be on the Red
Top spur vein. The 'bull quartz' vein of the Mother Lode traverses
the Martinez claim, 300 ft. west of the Hillside No. 3 workings. Still
farther west, on the Climax claim, are early-day Mexican workings.
Miller (Rihhon Rock) Claim adjoins the Superior Claim on the
north. Hayward and Lane prospected the two claims in 1900. The
shaft reached an inclined depth of 400 ft. (320 feet vertical). As this
work was done at a time when the State published few records, noth-
ing definite is known of the results. The vein in the shaft is said to be
2 to 4 ft. wide. There is no record of production.
Montezuma Mine near Nashville had supplied ore for many
arrastres in the early days of California mining, but the principal
shaft was flooded from 1871 to 1899. The ore that came from the
property during that period was from numerous other shallow work-
ings which prospected the vein for a length of 1200 ft. Production
was about $2,000 in 1890 and a 5-stamp mill was operated irregularly
during the next ten years.
In 1899 the old shaft was unwatered and the mine was active until
1907, with 10 stamps in irregular operation. From 1901 to 1907, not
including 1905 and 1906, the Montezuma produced $41,071 and the
recovery varied from $1.70 to $12 a ton. In 1905 and 1906, Gross and
Kleeburg of New York had this mine and the adjoining Havilah under
option. They crosscut 47 ft. on the 1200-ft. level of the Havilah and
drifted north a reported length of 1285 ft. It is claimed that ore was
found, but details are lacking.
Meanwhile, a new shaft had been sunk 360 ft. on the Montezuma
300 ft. south of the old 360-ft. shaft. In the old shaft, ore had been
stoped to a depth of 120 ft. and a maximum length of 250 ft. In the
new one the principal stope was 100 ft. long and extended from No. 3
level upward for about 175 ft. just south of the shaft. The vein here
was reported 8 ft. to 20 ft. wide ; but the dimensions given must be in
error as the tonnage indicated would be greatly in excess of actual
production.
In 1914, California Exploration Company leased the mine and
sank the new shaft from 360 to 1000 ft. inclined depth (899 ft. vertical),
starting in the hanging-wall slate. Three new levels were turned, called
500-, 800-, and lOOO-ft. levels. No. 5 or 800-ft. level, which showed
the most promise, was drifted 315 ft. north and 100 ft. south and east,
with assays indicating possibilities on the north side for about 150 ft.
in length. The 500-ft. level explored a total length of 250 ft., partly
in each direction, and the 1000-ft. level was run south 200 ft. The war
is said to have caused cessation of work.
In 1927 and 1928 a production of a few hundred tons of $10
ore was reported from the Montezuma. In 1931 W. Price and asso-
ciates formed the Nashville Mines, Ltd., and reopened the shaft and
levels down to and including the 1000-ft. level. A 10-stamp mill was
started February 3, 1932, and during part of that year crushed 35
tons of ore daily. On the 800-ft. level a length of 180 ft. was opened.
32
EL DORADO COUNTY
MOTHER LODE GOLD BELT 33
A raise was made from 1000-ft. to 800-ft. level and a drift started
about midway between was called the 900-ft. level. On the 1000-ft.
level, ore was found in a spur vein after running a new crosscut
125 ft. south of the old one. Where this spur entered the main
fissure good ore was found and had been followed 40 ft. on the
spur vein at time of visit in 1932. Later this spur was found to give
about 100 ft. of stoping length on the 900-ft. level. Ore was reported
12 ft. wide on the 900-ft. level and 8 ft. wide on the 1000-ft. level.
The main Mother Lode fissure, however, did not show much pay in
this section. This company crushed over 3000 tons of ore which
yielded about $8 a ton, with tailing carrying $1 to $2 a ton.
In January, 1933, they were succeeded by Montezuma-Apex
Mining Company, a subsidiary of Utah-Apex Mining Company. The
latter has greatly expanded the scale of operations, erected and put in
commission a new mill (see fl.ow sheet under Metallurgy), and has
operated steadily since with results which they state are satisfactory.
From 60 to 100 men have been employed and in June, 1934, about
2| tons of ore per man-shift was beingi produced.
The vein dips on an average of 60° E. with Mariposa slate walls
in most places, though in some parts the hanging wall is a gray schist
or 'mashed sandstone,' and small strips of greenstone are interbedded
with the slate. The shaft has been extended to 1300 ft. inclined depth,
and 1100-ft., 1200-ft. and 1300-ft. levels opened. The shaft dips about
66° E. and at 1300 ft. is 148 ft. from the vein in the footwall. The
Havilah and Montezuma shafts are about 1000 ft. apart, and both
mines are being worked ; the .1200-ft. level was being driven south
toward a point under the Havilah shaft. The 1200-ft. level of the
Havilah, driven years ago under the Montezuma (see ante) corre-
sponds to 1050 ft. inclined depth in the Montezuma. Besides the work
on the spur vein which was stoped 100 ft. long between 900- and
1000-ft. levels and less than that below, a new ore shoot has been found
and is being worked in the main vein. On the 1200-ft. level, this
showed 570 ft. in length, most of it ore, in June. For 250 ft.
this is reported to be 6 ft. wide, and the balance 4 ft. wide besides a
heavy gouge, varying from 2 to 5 ft. thick on the footwall. The gouge
is said to carry about 0.1 oz. of gold along the ore body. This ore body
extends from 100 ft. north of shaft to over 400 ft. south of it. On
the 900-ft. level, two faults moved the ore westward going south ; one
strikes N. 60° E. and the other east, but ore is found south of them.
An anticline was also noted which arched up the spur vein between
1000 and 1050 ft. depths, as if the hanging wall had moved upward.
A system of modified shrinkage stoping is used where the gouge
is not too heavy. In starting stopes timbers are put three sets high
(two above the drift). Grizzlies with 10-inch spaces are installed
every three sets (18 ft. center to center) on top of the second set with
bulldozing chambers, protected by heavy timbering on top of third set,
and chutes 18 ft. apart. Above in the stopes stulls are used as
required. With wide gouge or faulted ground square sets are used.
On the surface, a 12 by 16 in. Knight crusher and Gyrex screen
reduce ore to 1^ inches for the Marcy mills. The hoist is driven by
125-h.p. motor. Two compressors are operated by 150-h.p. and 75-h.p.
motors. About 240 tons of ore was being milled daily in June, 1934.
3—4156
34
EL DORADO COUNTY
Very creditable costs were reported from this mine for early 1934.
The total for extraction, exploration, hoisting, tramming, milling, and
amortization, including indirect costs, was given as less than $4 a
ton. With increased tonnage, using both Marcy mills full time, it
was believed this could be lowered. Poles for timbering are bought
locally, costing about one cent per linear foot per inch of diameter,
but it was stated that sawed Douglas fir could be brought from Coos
Bay at less than local dealers quoted.
Ophir mine and mill, two miles south of El Dorado.
Courtesy of The Sacramento Bee
Ophir Mine is two miles south of El Dorado in the footwall of the
Mother Lode. The workings are in and near the brecciated zone at the
contact of diabase and its various phases with quartz porphyrite. A
vein from a few inches to 14 inches wide had been followed 98 ft. west
on a very flat dip. Near the face the dip steepened and a wdnze was
being sunk here. In this winze, high-grade ore occurs in narrow
stringers where a dike showing flow structure and containing iron
sulphide and arsenopyrite occupies the contact of basic porphyry on
east and agglonierate on the west. This agglomerate forms the ridge
running north on the west of the workings. It contains corroded
MOTHER LODE GOLD BELT 35
fragments of the basic porphyry, others of a more nearly granitic
phase, and some of the dike rock, all cemented by a greenish gray
breccia.
About 100 ft. east of the adit portal a shaft had been sunk 36 ft.
on a quartz seam that had widened to 18 inches with a reported value
of $7.50 a ton.
A 2-stamp mill was put on this property early in 1933.
Oro Fino Mine is a mile south of Garden Valley in a narrow strip
of amphibolite schist. The vein where seen was 4 ft. wide, strikes
northwest to north and had been opened to a depth of 80 ft. with a
dip of 50° when visited. Ore was hauled to the Frog Pond mill in
1926 and the small tonnage crushed gave good returns. In 1930 a few
tons of high grade was reported.
Orum Mining and Development Company 's property was idle when
last visited, and the shaft was full of water to the collar. There was
a mill of 5 stamps, one concentrator, two gasoline engines, an old com-
pressor and a jackhead pump. It is on Martinez Creek near the
Union Mine.
Pacific Quartz Mine at Placerville is one of a large group of min-
ing claims owned by Placerville Gold Mining Company, extending for
three miles along the Mother Lode, from a mile south of American
River to Weber Creek ; numerous placer claims are also owned, hold-
ings comprising 1400 acres in all. Many of the claims were early-day
producers of which only a fragmentary history remains.
Pacific mine was found in 1852 and had a 2-stamp mill in 1854.
From then until 1861 the production was $480,000 the mill having
been increased to 4, 10 and finally 20 stamps. The production up to
1883 was about $1,000,000, and some production was made up to
1889 when $6,000 output was recorded. It then lay idle 20 years;
reopening started in 1910 but was suspended. In 1914 a 5-stamp
mill was built and small tonnages of ore that yielded about $5 a ton
were crushed then and in 1915. This was partly from the dump
and partly from the talc orebody.
The principal productive vein was the Pacific on the west side
of the lode. The Pacific shaft was sunk 700 ft. vertically and ore was
stoped from the 500-ft. level to the surface. This vein was thought
to have been lost by being faulted eastward between the 300- and
400-ft. levels. Later work in that direction failed to reveal any
ore. As described in 1888, this ore-shoot was 150 ft. long and the
average width of vein was 12 ft. Professor Thomas Price stated
the ore milled from $6 to $18 a ton with a tailing loss up to 75 cents
a ton. The concentrate made up one-half of 1% of ore and con-
sisted of "arsenical pyrites or iron, containing 3% nickel and assaying
$85 per ton in gold and $2 per ton in silver," according to him.
The shaft is in the black slate of the footwall at the 700-ft. level,
where a crosscut east 85 ft. cut a talcose orebody 75 ft. long by 7 ft.
wide. The black slate hanging-wall was encountered 130 ft. farther
east in the crosscut. From the 700-ft. level 200 ft. north of the shaft
a winze was sunk at an angle of 70° for an inclined depth of 1365 ft.
This winze entered the footwall slate at 1600 ft. in depth and con-
tinued in it to the bottom.
36
EL DORADO COUNTY
The vein here was in an ankerite zone and was ribbon rock in
places colored by mariposite. This zone was 300 ft. wade at the 700-ft.
level and 125 ft. wide on the 2000-ft. level where cut in drill-holes.
Extensive diamond drilling was done from the 1700-ft. and 2000-ft.
levels, but over 8000 ft. of holes drilled are said to have failed to
show ore.
There is a 5-stamp mill and other equipment at the Pacific shaft
in Placerville.
Pocahontas Mine, three miles south of El Dorado was opened in
1854 and in 1867 had a 10-stamp mill. The mine was then yielding
ore averaging $15 a ton from a vein 4 ft. wide, and had repaid all
expenses of opening and equipment. Work continued intermittently
until 1896. Two veins occur, the Pocahontas being 4 to 9 ft. wide
and the Empire, 300 ft. distant and 20 inches wide. Both dip east, the
Empire being the steeper ; the strike is curving, about northwest. The
mine workings are in a feldspathic porphyry variously classified as
diorite-porphyrite or quartz porphyrite. This rock is a phase of the
large body of granitic rocks of varying composition lying to the north
and northwest, around which the Mariposa slates take a curving course
northeast and north. The body of rock enclosing the veins on this
property has intruded the Calaveras rocks and the diabase on the foot-
wall of the Mother Lode. On the surface, the contact of the Mari-
posa slate is about a mile east. The claims cover 3000 ft. on the strike.
The mine was worked through two shafts, the Burlingham incline
400 ft. long (205 ft. vertical depth) and the Burke 45° incline 300 ft.
deep, south of it. They are 157 ft. apart on the surface but diverge
in depth. The Pocahontas vein was drifted north 500 ft. and south
200 ft. on the 100-ft. level and a total of about 1000 ft. on the 300-ft.
level of the Burlingham shaft. The ore was stoped out to a depth of
400 ft. on dip and for a length of 300 ft., being 10 ft. wide between
300-ft. and 400-ft. levels. From the 400-ft. level about 150 ft. south
of shaft a winze was sunk 125 ft. which is said to have struck a gouge
5 ft. wide carrying pieces of ore, and this may indicate a dip slip or a
contact ; the walls changed to slate near the bottom of winze ; this
is probably Calaveras slate.
The ore varied in value from $4 to $25 a ton. The amount of water
was moderate in the mine.
Poverty Point (Guildford) Mine, two miles north of Placerville,
covers nearly a mile along the course of the Mariposa slate. Claims
in this group are Iowa, Hidden Treasure, Bantam, Baltic, Humming
Bird, Poverty Point, Brighton, Bell and Fortuna. The ground is
on the south side of the the river canyon and the topography made
possible development through adits, of which four have been run.
These have permitted low operating cost. It is claimed locally that
the mine has produced about $500,000. There is a record of a little
over $200,000 output since 1901, of which nearly all was produced
between 1912 and 1917.
Two ore-shoots formerly' mined were stated to be 420 ft. and 200
ft. long. The former was mined for a width of from 3 ft. to 20 ft.
Recently a body of low-grade 'schist ore' from 2 ft to 10 ft. wide has
been stoped for about 200 ft. in length. Ore shoots occur in a zone
of schist and slate 30 ft. wide wdth a footwall of altered amphibolite
MOTHER LODE GOLD BELT 37
schist or similar greenstone, which intrudes the slates in a long narrow
dike. So-called east and west veins have been distinguished about
30 ft. apart. The hanging-wall or east vein had the larger shoot.
Ore is composed of 'stringer leads' in the slate or schist. The average
Avidth is said to have been 5 ft. During the principal recent period
of operation, under Guildford Gold Mining Company, the ore aver-
aged during favorable years from $4 to $5 a ton. The concentrate,
chiefly pyrite, ranged from 3% to 3^% of ore in such years, and
carried about six-tenths of the gold and silver ; this concentrate
varied from $40 to $88 a ton in yield.
The Guildford Gold Mining Company quit work in 1917, after
running the River adit level (150 ft. above American River) 600 ft.
In 1919 the mill containing 15 stamps burned, and the property was
idle except for a short time in 1920, until 1923 when El Dorado County
Mining and Development Company began work, and advanced the
River adit level 685 ft. They installed ten 1000-lb. stamps but milled
only a little ore in 1925. Some time later the Golden Horseshoe Min-
ing Corporation took the property and have been working it in a small
way since. They have sunk a winze below the old 500-ft. level adit
which was 127 ft. deep in February 1932. They made a small pro-
duction in 1931.
River Hill Group covering 178 acres of mining claims and mineral
rights 1? miles north of Placerville, includes the Gentle Annie mine,
which was a producer previous to 1899. Its shaft had then reached a
depth of 600 ft. and there were 4000 ft. of drifts. This mine had a
10-stamp mill. After the death of Melton, the owner, the property
was enlarged by adding adjoining ground and the River Hill shaft was
sunk and connected at 400 ft. with the old Gentle Annie workings
from which ore was taken in 1901 to supply the new 20-stamp mill.
In the next three years this new shaft reached a depth of 1050 ft. and
finally was sunk to 1550 ft. A drainage adit 2400 ft. long also con-
nected with the 735-ft. level. There are five veins on the property,
including the so-called dolomitic vein, similar to the second one men-
tioned under Pacific Mine. The shaft was between two of these
veins, which were opened by crosscuts from the 300-, 400-, 500- and
700-ft. levels. The River Hill was an important producer from
1901 to 1906 inclusive, yielding from $2.50 to $4.80 a ton.
The hanging and footwall veins were separated by a horse of
slate 5 ft. thick, according to "W. E. Christian. "With a width of 30 to
40 ft. between walls, ore was sometimes 20 ft. wide. Below the 1000-ft.
level, a fault crossed the veins from the footwall to the hanging Avail
and is said to have cut off ore. Ore-shoots were 200, 150 and 80 ft.
long, according to Christian.
Eolert Veerkamp prospect is in NW^ of Sec. 33, T. 12 N., R. 10 E.,
six miles north of Kelsey by road. It is on and near the contact of
Mariposa slate and a long, narrow diabase dike which runs northwest
along the west side of the Mother Lode, about one mile west of the
main lode. The land has been farmed for many years and only shallow
prospecting has been done.
Two veins occur here — one a heavy barren or low-grade, Avhite
quartz vein striking N. 25° W., which is faulted to the west, looking
north, by a smaller vein of bluish quartz carrying sulphide, and strik-
38
EL DORADO COUNTY
ing N. 15° E, The latter vein is claimed to assay well in places. The
reddish soil on the summit of the hill, and in the obtuse angle between
the veins carries gold and some shallow drill holes are reported to have
indicated possibilities of a considerable tonnage of ore. The material
is so much decomposed and the work is so shallow that it can not be
determined whether this gold comes from weathering of one or both
quartz veins, from ore at the intersection of the veins, or is from the
upper, oxidized part of a disseminated sulphide orebody or stringer
lead in the diabase; the latter appears probable.
The land had been taken under option in March, 1932, and some
work was planned.
Sherman Mine is a mile north of Placerville, south of Big Canyon
Creek. The principal period of production began in 1908 (though
there had been some output in 1905) and continued through 1911. The
total production during that period was about $136,000. The yield
per ton varied from $3.15 to $6.50 and average width of vein was
reported to be 5 ft., with two ore shoots 60 ft. long, between walls of
Mariposa slate.
A shaft was sunk at an angle of 74° (the dip of vein) to a depth
of 750 ft. and at a point 1250 ft. north of shaft on the 750-ft. level a
winze was sunk on the vein 350 feet deep. Most of the drifts were run
north, the total length drifted on vein varying from 250 ft. on 100-ft.
level to 1400 ft. on 400-ft. level. Most of the gold and silver were
obtained from the concentrate, which was principally pyrite and
formed 3^% to over 4% of ore. It was worth from $66 to $91 a ton.
The plant comprised a double-drum hoist, large compressor and
ten 1000-lb. stamps with 2 crushers and 5 concentrators.
Sliger Mine was found in 1864, and was known as a producer of
specimen gold ore, though the gold was more evenly distributed than
in many nearby mines. By 1874, an adit had been run 375 ft., cutting
the vein at a depth of 200 ft., and a shaft was sunk to connect with it.
The ore then was said to come on the footwall side of the quartz vein,
in north-raking shoots. The ore was crushed in a small mill and the
production was estimated at $125,000 to a depth of 170 feet. Later
operators sank to 300 ft. and are supposed to have produced $100,000
more but made no accounting.
Little was done thereafter until 1922, when Sliger Gold Mining
Company was organized, and the shaft was sunk to a depth of 500 ft.
on the dip of vein. Milling began in January, 1929, and good ore was
produced during the two following years. In the attempt to make
the mine pay its way, the shaft was not properly protected and caved
in early in 1931.
The country rocks are amphibolite, slate and serpentine, the latter
forming a narrow dike. The mine is at the contact with black slate
on the footwall and ankerite and serpentine on the hanging wall. A
strip of slate was probably caught up in the intrusive from which the
amphibolite was derived.
On the 350-ft. level, the crosscut was driven in a curved course
for 33 ft. throueh ankerite or similar mixed carbonates, stained by
mariposite. and likeAvise on the 500-ft. level. At the time of visit, a
raise had been put up in ore between these two levels, and ore had
MOTHER LODE GOLD BELT 39
been stoped for a length of 60 ft. and a maximum width of 19 ft. and
a height of 30 ft. above the 500-ft. level.
The principal orebody seen is on the footwall side and is a replace-
ment of an igneous member of the amphibolite schist series, probably
a dike. It is now highly silicified, with some carbonates,- and is thickly
impregnated with fine crystals of sulphides disseminated through the
rock. The ore has no definite wall but merges into low-grade rock.
There are two classes of ore in this part of the mine — so-called black
slate or schist ore and grey-schist ore. On the 350-ft. level, a drift had
been run 260 ft. north and was claimed to be in ore for 110 ft. ; on the
500-ft. level, the drift was 220 ft. long on the north side of shaft at
time of visit, of which 120 was claimed to be ore, which varies in width
from 14 inches to 19 ft. wide. This ore is hard and requires little tim-
ber. Most of the pay is in the sulphides which make up 3.7% of ore, and
contain from $75 to $375 a ton, nearly all gold. The concentrate con-
sists almost entirely of pyrite. The smelter assay of one lot of con-
centrate was:
Au 10.71 ounces
Ag 0.6 ounce
Sb 0.7%
Insoluble 23.2%
Iron 31.0%
Sulphur 32.5%
As 0.6% (in some lots)
Freight and smelter charges were $22 a ton. The operating cost
was low at that time. Ore was being milled with 15 stamps of a total
of 25. A 40-mesh screen was used, and a discharge only 2^ inches high.
Recovery was said to be about 80%. Ore value ranged from $5 to $15
a ton. Seven men employed were producing and milling 18 tons of
ore in two shifts.
In October, 1931, C. L. Wright of New Jersey and associates took
a lease on the mine and reclaimed the shaft. A 100-ton ball-mill and
flotation plant were installed late in 1932. Early in 1933, Middle Pork
Gold Mining Company was formed to continue work which has been
carried on continuously since. The underground workings have not
been visited by the writer since ,1930. In 1932, a winze was sunk 100
ft. from the 500-ft. level and a drift 200 ft. long on the 600-ft. level
was reported by Charles Mayotte, then superintendent, to be all in
ore, which crosscuts showed to be 32 ft. wide. He believed over
100,000 tons of good ore was reasonably assured, of an average grade
of about $10 a ton.
In that year, work was started on the surface outcrop of the vein
near the south boundary of the Sliger claim. Shortly after, suit was
started by Paul Ricci, the owner of the adjoining South Sliger claim.
This was terminated in 1934 by the purchase or lease of the latter claim
in July, 1934, by Middle Fork Mining Company.
Stamps have been displaced in the present mill, which uses a ball-
mill, flotation and gravity concentration. Two-stage crushing with
Blake and S.>Tnonds crushers is used ahead of the ball-mill, which
works in closed circuit with two Dorr rake classifiers. From the mill,
pulp passes over a Deister Overstrom concentrator which saves per-
haps 75% to 80% of the gold in a high-grade concentrate. The table
tailing is sent to a conditioner, then to six Kraut rougher cells and
40 EL DORADO COUNTY
two cleaner cells. Concentrate is hauled by truck to Selby smelter.
Mill capacity is about 70 tons a day. A high recovery is being made.
In 1934, a crew of 40 men in mine and mill was producing about
50 tons a day. This property should be a profitable producer for
several years.
St. Lawrence Mine. The following claims are included in this
group : North St. Lawrence, St. Lawrence, St. Lawrence No. 2, Guada-
lupe and the St. Louis, which is adjacent to the St. Lawrence on the
east, and the St. La^vrence mill site. The property is about eight miles
north of Placerville on a good road at an elevation of about 2000 ft.
The original location was made in June, 1867, by placer miners
who had followed the rough coarse gold upstream on Irish Creek and
Dutch Creek until they found the vein. The locators worked the mine
until March, 1871, when it was bought by Bateman and Company,
who put up a 20-stamp mill and continued the sinking of the shaft and
the opening of levels at intervals of 100 ft. The mine at the time of
this sale had reached a depth of about 600 ft. on the dip of the vein.
In a contemporary description of the property it was stated that
the quartz in the St. Lawrence occurs in lenticular forms not continuing
for any great distance but invariably found to come in again in similar
veins lying along the main fissure. At a depth of 550 ft. in the main
shaft the quartz is said to have entirely given out and gouge took its
place, following the well-marked footwall. At the 500-ft. level, 160 ft.
north of the shaft, the quartz gave out and there was in its place a 5-ft.
gouge showing slickensides on both walls. Before giving out in this
direction, the quartz jumped several times from the hanging wall to
the footwall and vice versa. The underground aspect appears to have
been similar to that of other mines in the Mariposa slate as the apparent
hanging wall is said to be repeated two or three times in parallel
slickensides.
In sinking the shaft from the 500-ft. level to the 780-ft. or eighth
level the work was in this broken-up ground.
The English company failed to supply money to carry on pros-
pecting work when the grade of rock taken out of the lower levels
became too low to pay expenses. The mine was attached by creditors
in September, 1874, and was sold to persons who started mining in
May, 1876, and after reaching the ninth level sank a A^dnze 200 ft.
deeper in the search for the continuation of the upper orebody. In
the eighth level north of the shaft they found the apex of a rich lens
of ore which proved to be very small. The deeper work from the ninth
level do'^\Ti resulted in the discovery of no new ore Avorth mentioning.
The record of the value of ore and the total production of the mine
is not complete. The original discoverers took out ore worth $10 a ton.
The English company could not work at a profit ore that went less than
$8.54 per ton, as is shown by a letter A\Titten by their superintendent
in 1874 when he advised against running the mill on ore of that grade.
For the year 1873 this company's reports showed 8062 tons milled:
bullion p^roduced, $141,002.13; average per ton, $17.49. The small
lens of ore below the eighth level is claimed to have paid $27 per ton
and to have yielded about $18,000. In a statement by Lieutenant
George M. Wheeler in 1878. he says the St. Lawrence up to that time
had produced .$465,000 and had cost $300,000. The mijie has been
MOTHER LODE GOLD BELT 41
idle since. This vein was explored: for a total length of about 200 ft.
north of the discovery shaft and 194 ft. south and so far as known
liractically no crosscutting was done after the pay-shoot disappeared.
The recoveries noted above were of free gold only.
Sunrise Mine, one mile northeast of Kelsey, near the Dalmatia
and supposed to be on the same vein, was another low-grade deposit
that made a record for low operating cost. Although equipped with a
10-stamp mill in the 1890 's, it was worked only in a small way and
irregularly". Though several crushings of ore were made, and an
operating cost of 63 cents a ton was claimed, there is no record of the
amount of gold produced.
Superior (Tin Cup) Mine, one mile east of Diamond Springs and
adjoining the Larkin on the north, was located in 1867 as the Reid
mine. It is described in detail in Report VIII of the State Mineralo-
gist. At that time it had been explored to a vertical depth of 160
ft. by a steeply inclined shaft 180 ft. long, and two adits, one 250 ft.
long and one 700 ft. long. It had a 10-stamp mill. The yield of ore
varied from $5.80 to $15 a ton, and concentrate worth $130 a ton
made up 5% of ore. The tonnage of ore was, however, small and the
mine was closed soon after. It remained idle until prospecting work
Avas started in 1900 by Hayward and Lane upon it and the adjoining
Miller claim on the north. Hayward purchased the Superior claim,
but nothing is known of his short-lived operations beyond the fact
that prospecting finally reached an inclined depth of 400 ft.
Taylor (Idlewild) Mine on the westerly section of the lode three
miles southeast of Greenwood was found in 1865. At the surface the
vein was two feet wide, but increased with depth and an average width
of 14 ft. was stoped during the best days of the mine. The footwall
is hard greenstone which runs through the property in the form of a
narrow dike. Mariposa slate forms the hanging wall. A well-defined
gouge occurred on the hanging wall, and considerable trouble was
caused by swelling ground. Stopes were filled with mine waste and
with surface rock dropped through a chute. The shaft for the first
300 feet was sunk in the vein then passed into greenstone.
The mine was reopened in 1888 after lying idle ; in that year it
had a 10-stamp mill and produced $4,000. In 1890, 10 more stamps
Avere added, and the 500-ft. level was opened and was producing 20
tons of ore a day, which averaged $6 a ton. The orebody was reported
30 feet thick on that level, consisting of "quartz, lime, feldspar, slate,
etc." Within two years the mine became the principal producer of
the county. The levels, 100 ft. apart, explored and developed an
ore-shoot 400 ft. long. Below the 500-ft. level, according to E. J.
Kendall, superintendent of the mine for 13 years, the orebody decreased
in size with no quartz below the ninth level. Crosscuts were run about
100 ft. on the 10th and 11th levels without results, and drifts were
run southeast 600 to 700 feet (probably to the property line) on the
200- and 300-ft. levels. The shaft was "sunk to 1225 ft. on an incline
of about 50° before work ceased.
Apparently there is no complete record of the mine's output, the
owner claiming tonnage records were lost by fire in 1906. Beginning
in 1893 and continuing several years, the annual output was from
42 EL DORADO COUNTY
$146,000 to $150,000. The mill capacity in 1893 was 110 tons a day
with 40 stamps. Estimating an average monthly run of 3000 tons
would indicate an average recovery of about $4.16 a ton. This, how-
ever, is at wide variance with the statement of E. J. Kendall who said
ore averaged $8.40 to $8.55 a ton. It is known the best ore was on
the hanging wall. The gold was finely divided as a rule, but at times
in sheets. Ore is described as typical 'ribbon rock.' Sulphides which
were of good grade in the earlier operations became too poor to ship
and concentrate was later cyanided at the mine. The mill capacity
was increased again in 1896, and the value of heads dropped because
of increasing tonnage handled. There is no record of output after
1900. The total production has been estimated at about $1,000,000.
The amount of dividends, if any, is unknown. But with production
averaging about two tons per man-shift for all employees, and with
cheap water power and timber, there should have been a fair return,
for a few years at least.
Union (Springfield) Mine. Although this mine is credited with
being the largest gold quartz producer in the county, there has been
little definite information available concerning it. Most of the work
was done upon it many years ago by operators who refused to divulge
results of their operations, and part of this activity was during a
period when the State was not publishing reports on mines. In the
period since 1916, the property has been idle and has belonged to
nonresident owners who have kept the records outside the State and
have failed to supply information requested. It is believed that the
production has been overestimated, as is common in such cases.
The surface of the present holdings (see claim map) supported
a large mining population in the early 1850 's, and the float ore was
worked in arrastres after the stream placers were exhausted. Professor
Silliman induced his relatives and friends to finance quartz mining and
the Union and Church (later worked as separate mines) were con-
solidated. A pay shoot north of the Union shaft is said to have yielded
$450,000 from 15,000 tons of ore mined before 1868. The Cosumnes
vein croppings and shallow workings on it west of the Union to a depth
of 120 ft. are said to have produced $150,000 more. In spite of the
good grade of ore found, the project failed and the mine lay idle
several years until Alvinza Hayward and Hobart purchased it. They
changed the name to Springfield and operated about 15 years. They
had a mill of fifteen 600-lb. stamps with a capacity of only 26 tons a
day. Concentrate worth $150 a ton was saved on Frue vanners and
treated by chlorination. In ,1886, near the latter end of these opera-
tions, it was stated'^ that the ore-shoot (probably meaning series of
shoots) was 800 ft. long and the vein averaged three ft. in width.
The Springfield shaft was finally sunk to a depth of 1640 ft. (vertical),
and the Clement shaft 900 ft. deep on an incline of 70°. Over 21,000
ft. of drifts and crosscuts are reported to have been run.
After an idleness of about 10 years, Union Gold Mining Company
began work and a 30-stamp mill was built. In 1897, a production of
$36,000 was reported. From then until 1909, only estimates of pro-
duction were made public. These indicate that from 20,000 to 40,000
tons of ore was crushed annually, yielding from $5 to $7 a ton. In
1909, the last year for which a figure is at hand, 12,000 tons yielded
1 Sixth Report of the State Mineralogist, pt. 2, p. 43, 1886.
MOTHER LODE GOLD BELT 43
a little over $5 a ton. During this period, the same company operated
the Schoolgirl workings, west of the Union, and separate figures for
the two are not available. The latter had a 20-stamp mill.
The Union was again reopened in 1914-1916 and some prospecting
was done, but the results of this were disappointing.
Five veins striking about N. 16° E. occur in the Mariposa clay
slates on this property. They dip 60° to 79° E. and are reported to
be 5 ft. to 10 ft. in average width. The main or Springfield shaft is
320 ft. east of the hanging-wall vein at the surface, crossing the vein
at the 1200-ft. level. The west gouge vein was also crossed by this
shaft about 60 ft. above the 1600-ft. level. Four ore-shoots, varying
from 100 to 250 ft. long, are said to have been worked out from the
1300-ft. level to the surface. The work done up to the time Hayward
and Hobart quit had been done almost entirely on the southernmost
1000 ft. of the property. When they drifted farther north, it is said
the vein broke into stringers. Under Harpending (1896-1909) a
crosscut was run east to search for the vein which had either been
faulted or had turned east. They struck a vein 1400 ft. north of the
north end of the Springfield old workings and 700 ft. south of the
Church line. Ore was opened here 230 ft. long in a winze and it was
from here that much of the later production came.
Late in 1934, Gold Fields American Development Company began
unwatering the Springfield workings for the purpose of further pros-
pecting under ground. About 30 men have been employed. An
electric power line was built and pumps were started at the end of
July. J. T. Boyd is manager.
War Eagle Claim is the south extension of the Big Chunk. It has
been a pocket producer only. There is an old shaft believed to be
80 feet deep with which an adit 150 feet long connects. This adit
shows a vein about 18 inches wide.
Seam Mines
Along the Mother Lode in El Dorado County beginning at Placer-
ville and extending into Placer County, a peculiar kind of gold quartz
deposit has been extensively worked by the hydraulic process. They
liave been known from the earliest days of mining in that region as 'seam
mines' or 'seam diggings.' These deposits occur in both the Mariposa
clay slate and in the amphibolite schist. They consist of broad and rather
well-defined lodes in which the gold occurs generally in narrow veinlets
of quartz and at times in the gangue rock itself. In these lode zones,
which are sometimes nearly 100 feet wide, there may be several systems
of quartz veinlets, each system having a definite strike and dip within
the main lode. Generally these stringer systems are bounded by
the main lode walls which are often quite definite. At times in such
a lode the quartz stringers may increase in size to solid lenses several
feet wide. In such cases it may be difficult to say whether a mine
should be called a 'seam mine' or a quartz mine. The pay in the seams
occurs as a rule at the intersections of two such stringer systems or
perhaps where the stringers of such a sj^stem intersect one of the
larger lenses of quartz. At Georgia Slide, for example, there are
three systems of seams. One system strikes northeast and dips 45°
northwest; another stands nearly vertical with a northwest strike and
the third which follows the strike of the schistosity of the schist and
44 EL DORADO COUNTY
slate a little north of northwest, dips 75° east. The principal pay
in this property was found at the junctions of the first and third seam
systems and on the side of the quartz away from the so-called sand
streaks.
The peculiar circumstances found by the early miners who first
investigated these deposits led them at once to experimentation with
the only methods of mining they were acquainted with at the time.
They found that these seam zones were decomposed to such an extent
that a large part of the gold in the upper portions of the deposits
could be saved by the ordinary sluicing and hydraulicking methods,
as there was available at the time considerable water for mining. This
method of operation came into quite extensive use through that entire
section even during the decade between 1850 and 1860 and continued
up to the time of the prohibition of hydraulic mining. There are few
definite records of actual results of these operations but such figures
as are available are extremely interesting. The following are some
of the results as reported in 1874 by Amos Bowman :
The Grit mine at Spanish Dry Diggings from 1860 to 1867 pro-
duced $100,000 but a great deal more had been taken out as early as
1852 and it was estimated that the mine had produced in all $300,000.
The Beatty mine at that time had been worked for 17 years and was
producing at the rate of $1,000 a month clear of all expenses to the
owner of a one-eighth interest. The Frerich claim of Greenwood had
produced about $100,000.
Some of these properties, as nearly as can be figured, produced
over a dollar a cubic yard and were worked at a cost only a little
higher than the ordinary hydraulic mine. As work progressed, how-
ever, in these mines it was found the method of operation had a
strictly limited application at depths varjdng from a few feet to 60 feet.
The seam zones began to show the fresh rock not decomposed by
the agencies which had softened the upper part and this hard rock
could no longer be worked by the hydraulic method. Due also to the
slabby and angular character of the material, these mines had to be
equipped with sluices having a much higher grade than the ordinar\^
placer mining sluices so that in mining for any length of over a few
hundred feet along one of these seam zones the miner would eventually
find the upper end of his sluices coming up to the surface and work
would have to be stopped on account of lack of grade.
The most important group of 'seam mines' is that at Georgia Slide,
an old mining camp 2 miles north of Georgetown. In its course north-
westward through El Dorado County the main belt of the Mariposa
slate is separated into two branches by a large lens of amphibolite
schist and the Georgia Slide mines are in this schist and on the eastern
branch of the slate where Canyon Creek has cut a deep trench across
the gold-bearing formations exposing them in cross section in such
a way as to facilitate cheap hydraulic mining. The mines here will
be de-scribed under the heading of Georgia Slide mines.
The following is a list of the principal 'seam mines' that have
been worked in the regions mentioned :
Blasdel seam mine is on Dark Canyon north of Georgetown. This
seam belt runs about 2000 ft. in a northerly direction but has not
been extensivelj^ worked.
MOTHER LODE GOLD BELT 45
Carrol claim is on the east slope of Greenwood Hill. The pit here
was 80 feet long by 40 ft. wide and 15 ft. deep, but the production
is unknown. There are three systems of quartz seams of which one in
particular has produced gold.
Castile mine between Empire and Manhattan canyons, near Garden
Valley. This contains two quartz veins separated by 3^ ft. of slate
lying in a seam zone which has been hydraulicked for a length of
100 ft. by 70 ft. wide and 18 ft. deep.
The Cedarherg mine, about a mile south of the Sliger on the east
side of American Canj'on had an interesting history. Cedarberg and
his partners had prospected without success until thej- had exhausted
their funds. Thej' then applied to the water company for one day's
free supply of water which was given them, but their flume was in
such poor condition that it broke when the water was turned into it
and the water in running to waste down the hillside uncovered a
quartz vein three inches wide with some parallel veinlets. The part-
ners mined out here 90 cubic yards which yielded $45,000 to a depth
of 25 ft. As work went deeper on the vein it increased in size to a
width of 2 ft. at a depth of 200 ft. An ore shoot 50 to 80 ft. long
was worked and the mine was famous for a time as a producer of
beautiful gold specimens, the free gold occurring in white quartz and
the sulphides in a bluish quartz. Some attempts have been made in
later years to bring this property into operation as a quartz mine
but these have not met with success.
West of Cedarberg is a seam belt which is cut through by the
American Canyon and which contains the George, Smith, American,
Conner, and Mauley seam mines concerning which there is nothing
of particular interest available.
The Cranes Gulch or Whitesides mine had produced $100,000
from a pit 150 ft. wide by 250 ft. long by 70 ft. deep before 1874. This
would indicate an average yield of over one dollar per cubic yard.
French or Nagler claim, which adjoins the town of Greenwood,
has an old hydraulic pit of probably two acres in area which has been
worked out to a depth of nearly 100 ft. The seam belt here was about
200 ft. wide with porphj^r}^ on the M^est and decomposed slate on the
east. From the figures quoted by Bowman it would appear that the
production of gold from the hydraulic mining operations here pre-
vious to 1874 had amounted to about $100,000 or an average of about
$3 a cubic yard but this figure seems excessive. The largest amount of
pay is supposed to have come from the intersection of a cross vein
with the main vein. A shaft was sunk at this intersection in early days
and the ore taken out is said to have milled extremely well. This
vein shows mineralized schist with two feet of solid quartz. The
record of the water company which sold water to this mine showed
that from the total production mentioned over $20,000 had been paid
for water or an average of $80 a week.
The Fisk or Porphyry ledge is one-fourth mile north of Placer-
ville and has produced large sums. In 1870 Fisk took $3,000 out of
a space 8 ft. by 10 ft. hy 20 ft. and the claim produced considerable
ore carrying $100 to the pan with pieces weighing as much as 25
to 40 ounces each.
46 EL DORADO COUNTY
Georgia Slide Mines. In this group are the Bhie Rock claim con-
taining 27 acres, the Pacific claim of six acres, the Bcatty claim of
26 acres and the Parsons claim of 20 acres. The Beatty claim was
operated continuously from 1853 and the Pacific and Blue Rock from
1856 until 1895 when the operators were notified to discontinue min-
ing by the hydraulic process. The geology of these claims has already
been mentioned. In later years when the rock began to be a little
firmer than in the early workings powder was used in large quantities
to break down the bank previous to washing with the hydraulic
giants. Quartz specimens containing gold Avere sorted out by hand as
far as was possible and were crushed in a hand mortar. It has been
stated that these properties produced from $2 to $3 a ton in gold which
was worth $18.50 an ounce. After 40 years of operation the bank on
these properties was 150 ft. deep and an immense amount of tailings
had accumulated in Canyon Creek. The various operators had a work-
ing agreement by which the grade was lowered at the different prop-
erties in such a way as to permit all of them to continue work.
The deposit at Georgia Slide is essentially a large lenticular body
some three-fourths of a mile long and nearly 400 ft. wide at the widest
point. No close estimate can be made of the total amount of gold
which has come from this deposit. Oregon Canyon, which is claimed
to have produced $2,000,000 in a length of three-fourths mile, and
the lower course of Canyon Creek, which produced $1,500,000, derived
their gold from this seam belt. Several millions more were produced
by the seam mines mentioned above and there are still remaining a
million tons left unworked in the deposits above the level of Canyon
Creek. In recent years the deposit has been extensively sampled with
the idea of making a large low-grade quartz mine. These plans, how-
ever, were never carried out. Several small stamp mills were operated
on seam mines here after the prohibition of hydraulic mining. These
handled selected ore in a small amount.
Grit mine at Spanish Dry Diggings was first worked by Spaniards,
who carried the dirt down the steep canyon to American River to wash
it. It was most productive in 1852. Between 1860-1867, it produced
$100,000 and in 1865 a mass of beautifully crystallized gold whicli
weighed 101.4 ounces Troy, and came from a shaft sunk a few feet
below the bottom of the hydraulic pit, which was 50 ft. by 150 ft.
by 60 ft. deep. No particular vein was noted until a depth of 40 ft.
was reached, where lenses of quartz were found with a maximum
width of 3 ft. over a length of 30 ft. These were followed 100 ft.
deeper, and the mine then lay idle many j^ears after a reputed produc-
tion of $300,000.
In 1919, two men struck rich specimen ore in the vein at the
bottom of the old workings and a stock company was formed with
the idea of developing milling ore. Although several thousand dollars
was produced in crystallized gold, the venture was not a success. The
gold occurs in quartz and calcite, with amphibolite schist and slate
walls 3 ft. apart, and the lens of ore was 30 ft. long, with the richest
values at one end. Both walls here carry considerable pyrite in
coarse crystals.
The Sliger mine in Sec. 25, T. 13 N., R. 9 E., and the Hines mine
half a mile north of it were both worked in the early days as seam mines
and then lay idle for a long time until a few years ago when work was
MOTHER LODE GOLD BELT 47
resumed and both of them have shown promise of developing into good
quartz mines. They are mentioned elsewhere in this report.
The Hart mine near and north of the Castile has a seam zone
which has been hydraulicked for a length of 175 ft., a width of 50 ft.
and a depth of 40 ft. After the fresh rock had been reached in this
pit considerable prospecting was done to see if the ore was rich enough
to be handled in a quartz mill. An adit was run for a length of 320
ft. which encountered four separate stringer systems or veins all
parallel in line within the seam zone. On the first of these veins a
drift was run 175 ft. south and on the fourth a drift 70 ft. long was
driven. This property has lately been taken under option by J. A.
Flink and others. Underground these veins appear as stringer leads in
the amphibolite schist. An 8-stamp mill was put on this property in
1930 and a mill test of 11 tons was made from the first vein. Although
it was reported that this gave satisfactory results there has been
nothing further done with the property until 1933, when work was
resumed and is being continued.
The Hodge and Lemon mine is a north extension of the Fisk and
is on the north end of Quartz Hill. The seam zone here has been
mined for a length of half a mile on these adjoining claims and for
several hundred yards there is an old open cut which was 30 to 40
ft. deep, with underground workings of unknown extent below the
pit. The cross veinlets in this mine dipped 40° north and rich pay w^as
found where these veinlets strike the east wall zone. This zone con-
tinues on through Poverty Hill.
The Spanish mine on the hill west of Greenwood has a seam belt
100 ft. wide. An area 400 ft. long by 24 ft. wide when hydraulicked
went 800 ounces gold worth $17 an ounce or a total value of $13,600.
Much work has been done on this property in later years in the
endeavor to develop it into a quartz mine but so far this work has
not been successful. The pay was followed 80 ft. below the bottom
of the pit and the vein was drifted on 20 or 30 ft. in each direction.
The St. Lawrence seam mine produced $23,000 in 10 months with
a crew of four men using 100 miner's inches of water which cost for the
above period $8,000.
In the Spanish Dry Diggings district there are three seam belts,
the one farthest west having been worked at the Waion mine, the one
at Spanish Dry Diggings containing the Grit and the Barr and Cross-
ton and the third, a quarter of a mile east of the Grit, called the
Fargo belt.
The Waun mine is a half mile west of Spanish Dry Diggings.
Four series of seams have been worked, first by the hydraulic method
and two of these were followed into the hill by tunneling. This seam
belt is 50 ft. wide. The gold occurred in quartz veinlets running
parallel to the strike of the seam zone and also intersecting veinlets
crossing the seam belt.
The French Hill mine near Spanish Dry Diggings is on this seam
belt, one-half mile south of the Waun mine.
The Sivift and Bennett claim at the southern edge of Georgetown
paid a good profit in the 1870 's; some of the rock yielded a dollar
to the pan.
48
EL DORADO COUNTY
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MOTHER LODE GOLD BELT 55
AMADOR COUNTY
Geology
Most important of the Mother Lode counties from, the standpoint
of gold production and mine development, Amador County has also had
the highest percentage of successful lode mining operations of any
region in the State. With a length of 20 miles traversed by the Mother
Lode formations, the section between Jackson and Plymouth, ten miles
long, has been most intensively developed and has yielded most of the
gold produced in the county.
It is believed that the geologic notes herein under the individual
mine descriptions are sufficient to emphasize the most important points,
which are only briefly alluded to in these introductory paragraphs.
By far the greater part of the production has been from mine
workings in the Mariposa (Jurassic) clay-slate, in the vicinity of
contemporaneous, interbedded greenstones now having the aspect of
dikes due to the tilting of the entire series, but originally deposited as
mud flows of volcanic ash and breccia and other extrusive rocks,
formerly called augite porphyrite, later known as meta-andesite. As a
matter of fact, the alteration of such originally igneous members found
in the mine workings has often advanced so far that even the expert
petrographer can not positively name the original rock.
Veins in the slate are typically fissure fillings of white quartz,
often ribboned with thin slate layers. The gold in such ore is mostly
free; the percentage of sulphides is uniformly small, 1% to 2%; and
the amount of gold associated with the sulphides so closely that it
is recovered only after smelting or cyanidation, is not generally over
20% of the total. There has been little variation in the character of
these ores in the range of about 6000 ft. on the dip so far explored.
The ribbon ore of course indicates repeated reopening of the fissure
along the walls of the veins, with additions of vein matter.
At depths varying from a few hundred to several thousand feet,
the veins pass on the dip from the Mariposa clay-slates into the altered
igneous rocks (meta-andesite, amphibolite schist, or as commonly called,
greenstone). When this happens, the vein commonh^ flattens in dip,
takes on a more massive character, and becomes itself of lower grade,
often too lean to make ore; but lenses of a different variety of ore are
usually found in the nearby greenstone walls, close to the vein. These
are the 'gray ore bodies' or 'schist ore.' They consist of hydro-
thermally altered greenstone, or amphibolite schist, containing 2% to
4% of disseminated auriferous sulphide, mostly pyrite. This ore is
largely ankerite, but with considerable silica and some albite. Often
such ore in the schist is traversed by a network of quartz stringers and
is called a 'stringer lead.' From 50% upward of the gold in it is
associated with the sulphides. Commonly, though not always, it is of
lower average grade than the slate quartz ore.
These gold deposits have been classified as mesothermal, therefore
as having been deposited at moderate depths. How much deeper they
must be proven to extend before they may be considered deep-seated
56
AMADOR COUNTY
MOTHER LODE GOLD BELT 57
is an interesting question. Of the 'true fissure' type, they have been
distinguished from the younger, bonanza type of gold deposit by the
persistence of the ore in depth and by the repeated occurrence of ore,
usually in lenticular form, particularly on the dip. As a corollary of
this, so-called barren zones may be expected sooner or later, through
which sinking may have to be carried several hundred feet in low-grade
material before another orebody is found.
The ore-shoots are generally so much longer on the dip than on the
strike that the old empiric rule regarding these relations cannot be
applied. Many of the better ore-shoots can be quite definitely cor-
related with the junction of a spur vein or link or cross vein with the
main fissure.
In Amador County especially, experience has shown that ore is not
necessarily confined to any particular channel in the slate, but may
occur in either the footwall or hanging-wall sections or in the middle
of the slate, if bodies of interbedded greenstone of sufficient size
are there and if other conditions are right. The whole width of the
slate, under these favorable conditions, must be crosscut from massive
footwall greenstone to hanging-wall greenstone before the possibilities
of finding ore can be safel}' considered as exhausted. Massive contact
quartz veins however are seldom themseh-es important ore producers.
The general location of the lode was determined by the course of
an ancient, pre-mineral major fault zone along which compressive
strains (caused by the growth of the Sierra Nevada with the intrusion
of its granitic batholith) found relief in rupture with reverse faulting.
This fault zone, following here a belt of weak rock (Mariposa slate)
and weak contacts (slate-greenstone) was a locus of movement over a
long period, favoring the formation of ore by the building up of ribbon
veins b}' additions of vein matter on the side next the wall. After
the period of compressive stresses there must have occurred subsidence
on the hanging-wall side sufficient to open tension fissures, which in
many cases helped form orebodies at and near their junctions with the
main veins. Some important oblique faults, crossing the strike of the
lode, have in several cases limited ore deposition in particular mines.
"Whether or not such oblique faults are merely a phase of the post-
mineral adjustment, which cut off orebodies, or are pre-mineral faults
whose gouges dammed up the ore-bearing channels, is not always clear ;
but there has certainly been post-mineral moA'ement on some of them.
The definition, extent and importance of post-mineral faulting are
debatable and hard to arrive at because of the homogeneous nature of
the slate and the absence of characteristic bands or beds that might be
used as markers; also to the relatively small extent of vein opened at
one time, and the rapidity with which old workings close.
Although the Mother Lode follows the Mariposa slate across the
entire county, the developments north of Plymouth and south of Jack-
son have so far not brought in any mines as important as those in the
10 miles between these towns. A little north of Martell the Mariposa
slate is separated into two sections by a lens of the altered andesite
from a few hundred feet to one-fourth mile wide and from Jackson
southward Calaveras (Carboniferous) rocks are in places in contact
with the eastern strand of the Mariposa slate. The Zeila and the
Hardenberg have been the principal developments on this side, lying in
58
AMADOR COUNTY
the region of the easterly amphibolite schist contact. Between these
two mines, there are five or six veins, the Zeila Mine being on the most
easterly, the Amador Queen No. 1 occupying several of them of which
the 'main vein' showed a width of 60 ft. or more of stringer lead
material in the amphibolite schist. There are four such veins or leads
in a width of 800 ft. here. No important ore-shoots have been found in
this section, between the Zeila and Hardenberg. Quartz is typically
in small lenses in the schist here.
The western strip of Mariposa slate running from the Kennedy
and Argonaut southeast and south is a very narrow band which carries
gold deposits of a kind entirely different than those on the east. South
of the Moore Mine this westerly band is known as the Black Metal Belt,
containing the Valparaiso, Mammoth and Amador Queen mines, pro-
ducers of high-grade ore, much of it in specimen form, with arseno-
pyrite which gives rich concentrate. Besides these three mines which
have been the larger producers, the McKinney, Crannis, St. Julian and
Marlette claims have also yielded pockets.
Geography, Climate, Water, Timber, Power
Amador is the central county of the Mother Lode group, extending
from the lower foothills bordering Sacramento Valley on the east, to
the summit of the Sierra Nevada. The Mother Lode occupies a rolling,
park-like area dotted with small scattered oak trees, crossed by the
Cosunines River on the north county -line and the Mokelumne River on
the south, and varying in elevation from 700 to 1600 ft. A broad-
gauge railroad from lone to Martell, the latter directly on the Mother
Lode, connects wdth main-line railroads, and a fine road, part of the
State highway system, traverses the length of the lode with good paved
highways entering also from Sacramento and Stockton, both about 50
miles distant in the great central valley on the west. The annual rain-
fall at the Kennedy Mine ranged from 16 to 55 inches during a period
of 30 years, with a mean of 33 inches. Snow is nearly unknown. Most
of the rain falls between November 1 and April 30 and the other
months are dry. The growing season, averaged 262 days for 17 years.
Summer temperatures of 100° or more are not unusual in July or
August, but the humidity is so low that heat prostrations are almost
unknown.
ANALYSIS OF GOLD PRODUCTION OF MOTHER LODE MINES IN AMADOR COUNTY FOR
CERTAIN YEARS*
Year
Number
of mines
Tons of ore
Gold and
silver,' aver-
age per ton
Tons cone.
Value cone.
per ton
Total value,
gold and silver
3915
13
19
14
8
7
12
7
815,675
492,103
1£9,076
311,462
286,659
233,675
213,865
182,650
$4 74
6 03
8 31
8 25
8 02
7 12
6 63
6 67
17,155
23,657
3,624
2,844
5,836
4,182
3,962
$79 91
44 71
104 65
114 01
79 63
78 18
75 17
$3,870,010 00
1918 - -
1920 - -
2.968,526 00
1,653,825 00
1924
2,555.625 00
1928
2,2f8,490 00
1930....
1931
1.664.895 00
1,417,836 00
1932
1,219,794 00
* From compilations made by the U. S. Geological Purvey and U. S. Bureau of Mines.
' With silver at $1 an ounce, the silver content of these ores averages only 5 to 6 cents a ton; in 1932, with silver
averaging 2S.2 cents an ounce, it amounted to 2 cents a ton.
MOTHER LODE GOLD BELT
59
Though some companies have water rights, the supply comes prin-
cipally from a public utility which also controls electric-power distri-
bution. The water, used also for generating electricity, comes from
reservoirs in the high Sierra Nevada to the east.
Good pine timber is obtainable 15 to 30 miles to the east. Electric
power lines, fed from a hydroelectric plant a few miles east of the lode,
serve the Mother Lode mines.
Gold ar
d Silver Production
af Amador County, 1880-1933
Year
Gold,
value
Silver,
value
Year
Gold,
value
Silver,
value
1880
$1,495,053
1,450,000
1,500,000
1,590.000
2,000,000
2,145,591
1,874,062
1,979,956
1,750,000
1,560,975
1,459,952
1,395,962
1,210,383
1,505,973
1,331,916
1,391,929
1,523,351
1,324,472
1,806,363
1,544,868
1,373,788
1,823,827
1,629,151
1,609,744
2,060,574
2,445,815
2,260,373
2,116,182
11,953
1,500
1908
1,878,175
2,298,785
2,646,246
2,832,395
2,796,104
2,901,898
3,082,002
3,894,125
3,660,550
3,664,164
3,249,385
2,920,492
1,788,793
2,167,443
2,241,100
1,734,133
2,706,508
2,338,101
2,167,275
1,922,714
2,236,922
1,601,861
1,840,191
1,549,073
1,307,760
1,945,261
13 '39
1881
1882
1909
1910--.
16,701
20,916
28 899
1883
1911
1912
1884
2,000
3,700
6,136
2,069
3,500
6,398
9,357
13,895
8,008
5,230
280
1,089
3,767
3,477
1,742
6,902
14,915
7,444
2,686
4,336
4,055
17,930
14,579
13,515
32,037
18,097
17 032
1885
1886 -
1913
1914--.
1887--.
1888
1915
1916
1917
1918--
20,409
18,705
21,358
29,590
33,254
19,780
35,460
32,287
15,153
18,251
16,123
1889
1890.--
1891
1892
1893
1894- .
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933- _-.
Total values
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
13,422
11,319
14,317
9,392
7,100
4,783
3,865
6,471
1110,529,806
$638,323
Alpine ("Wheeler) prospect adjoins the Plymouth on the north,
the shaft being only about 300 ft. north of the north end line of the
Empire. This claim was opened in the 1860 's and the stock was traded
in at San Francisco in the earlj^ 1870 's, when there was a 10-stamp mill
on the claim. After a depth of 400 ft, had been reached and $78,000
had been paid in assessments with no dividends, work was stopped.
A few thousand dollars was produced in 1895, after which the claim
was idle until 1910. The deeper shaft was subsequently sunk to 600 ft.
on an incline of 55°, the deeper levels being at 500 and 600 ft. There
was also another shaft, 200 ft. deep. No important orebody was found
and work stopped in 1914.
The Mariposa slate on this claim is cut by the Alpine greenstone
dike, which here dips about 52° SE. and strikes nearly NE. The shaft
struck this dike at a depth of about 200 ft. and followed the green-
stone on its hanging-wall side to the bottom. A vein called the Alpine
was found at this contact and followed on a curving course 700 to
800 ft. northeast. It may be a spur of the Empire vein. At a point
80 ft. west of the shaft on the 500-ft. level, the Alpine vein joins and
is terminated by a vein striking north, persumably the Empire vein, on
which considerable prospecting was done.
60 AMADOR COUNTY
The greenstone-slate contact is near the Plymouth end-line on the
600-ft. level.
Amador Gold (Aetna) is 1^ miles south of Jackson. Most of the
work was done before 1900. A wide vein of quartz occurs at the
contact of Mariposa slate (footwall) and amphibolite schist (hanging
wall). An inclined shaft was sunk 700 ft. by 1890. Levels were turned
at 350, 450, 550 and 650 ft. and some stoping was done, but production
was evidently small, that of record amounting to only a few hundred
dollars. At least 750 ft. had been drifted by 1890 on the 550-ft. level.
There was a 60-stamp mill on the Aetna.
The Moore Mine lies a little west, and when it was last worked the
Aetna vein, or one so named, was prospected. (See Moore.)
Amador Queen No. 1, two miles south of Jackson, was extensively
prospected between 1890 and 1901 by Jackson Gold Fields and Jackson
Exploration and Development Company. The only recorded production
was a few hundred dollars a year during the above period from rock
taken out in the course of prospecting.
The shaft was sunk 1250 ft. on an incline of about 65° on the
contact zone, with amphibolite schist hanging wall and slate footwall,
there being first Calaveras rocks, and farther west Mariposa slate on
the footwall side. Hunts Gulch is believed to be the surface expression
of a strike fault. Drifts were run north 500 ft. or more on the 400-,
500-, and 800-ft. levels, and drifting was also carried south on these
levels for an unknown length. A west crosscut was also run 250 ft.
on 500-ft. level, where a vein 28^ ft. wide was reported, but too low
grade there to pay. The workings were said to be nearly all in amphib-
olite schist, closely folded and twisted, and with many seams and lenses
of quartz. Average grade must have been quite low.
Amador Queen No. 2 is two miles south of Jackson on the narrow
band of Mariposa slate called locally the 'black metal belt.' The
Valparaiso and Mammoth mines are similar geologically, lying on the
same belt, all three being known as producers of 'specimen' ore with
arsenopyrite.
The Amador Queen No. 2 was opened by a crosscut adit 1200 ft.
long which reached the slate-greenstone contact. From here a drift
was run 1000 ft. south and 460 ft, north. An internal shaft was also
sunk 900 ft. on the dip of the slate, 62° E., giving a total inclined
depth of 1212 ft. Levels were run at 500 and 700 ft. in depth in the
shaft. In late years, however, the shaft has been under water and the
work at time of last visit was in a raise near the end of the south drift
on the adit level. This mine has been worked every year in a small
way since 1918; before that, operation appears to have been irregular,*
although the greater part of the underground workings had been run
by 1900. The production reported in late years has been mainly from
high grade and often from 'specimen' ore and has averaged a few
thousand dollars a year.
The interlayered schist and slate seen in the accessible workings
showed no pronounced fissures or gouges. The formation being mined
at the time near the south end of the workings was a very hard, blocky,
siliceous schist. The band said to carry gold there was a strip of slate
MOTHER LODE GOLD BELT 61
about 4 ft. wide, containing gold-bearing stringers of white quartz
which terminate at the walls of their immediate slate band. The gold
occurs with arsenopyrite and the concentrate sometini,es is worth several
hundred dollars a ton, although occurring in only small quantity.
Amador Star (Rhetta) Mine, 3 miles north of Plymouth, covers
130 acres (agricultural patent) in Sec. 23, T. 8 N., R. 10 E. Previous
to 1900, it had been worked through a shallow crosscut adit, which
struck the vein 422 ft. from the portal, going nearly due west ; thence
running south 37 ft. and south of southwest 137 ft. Some ore was
mined about this adit (to a depth of 100 ft.) and crushed at the Bay
State mill; the amount and value are not known as the two were
worked by the same company. Two veins were reported ; one at the
contact of Mariposa slate hanging wall and greenstone (altered diabase)
footwall, and the other branching from it and running nearer north in
the slate. The mine map, however, shows only one, although Storms
reported that "Both of these veins have been explored with satis-
factory results."
After the adit mentioned was driven, a vertical shaft was sunk
about 1917 to a depth of 580 ft. with one level at 500 ft. from which
a crosscut was driven 150 ft. to the greenstone and slate contact.
Along this a drift was run 470 ft. north and 150 ft. south, following a
small vein which gave low assays. These workings did not connect
with the old adit, although the north drift runs almost 100 ft. beyond
the old adit. Several crosscuts were run west to the greenstone on the
500-ft. level without finding ore.
The assays on the adit level indicated that a length of a little over
100 ft. showed promise of producing ore below. The fact that the
downward extension of this ore was not encountered on the 500-ft.
level raises a question as to whether the ore passed into a fissure in
the slate, or raked away from the lower workings. In 1931 Amador
Star Mining Company began work from the 300-ft. point in the shaft
and reported striking a promising prospect 225 ft. west. On account
of lack of funds, water had been allowed to rise again above this point
at time of visit, so it could not be seen.
Since the above was written, the property was leased with option
to purchase to Arthur Hamburger, who did considerable work under
the title of Hamburger ]\Iines. This included a crosscut run about
1000 ft. eastward on the 500-ft. level in search of a hanging-wall vein.
No such vein was found, the rocks penetrated consisting of Calaveras
schists with the interbedded igneous rock showing flow structure in
places, which is occasionally seen in this formation. Some work was
also done on the 300-ft. level which was 670 ft. long early in 1933 ; and
on 500-ft. level, mostly clearing old workings or running new ones
parallel to the old. A mill was erected using the flotation system (see
under Metallurgy). Hamburger later formed the West American
Consolidated Gold Mines and about 40 men were employed when the
place was visited June 15, 1934. Work in the levels had been
stopped pending the sinking of the .shaft to a depth of 900 ft. The mill
was also to be closed temporarily.
The vein on the 500-ft. level is reached by a crosscut 150 ft. north.
On this level former operators had drifted ,150 ft. south and 750 ft.
62 AMADOR COUNTY
north. The present company ran a drift parallel to the old one on the
south, and are reopening the old north drift. In the south drift, two
raises for stopes have been started. The vein in the face shows 2^ ft.
of quartz, a small fault there showing the upper segment thrown its
\\idth horizontally eastward and onlj^ about one foot vertically down-
ward. Elsewhere it shows greater width, increasing northward to a
maximum of 8 to 9 ft. in a distance of 400 ft. Where it has this width,
it consists of a strand of quartz on each wall separated by several feet
of slate and quartz stringers with considerable pyrite. The superin-
tendent claims heads worth about $6 a ton from the small amount of
rock milled.
Anita or Bright Mine is one-half mile southwest of Jackson. The
surface was worked in early days, but no depth was reached until Anita
Gold Mining Company began sinking in 1895. They sank an inclined
shaft at an angle of 63° in and near the contact of the footwall green-
stone and the narrow strip of Mariposa slate which extends south from
the Argonaut Mine and carries the western branch of the Mother Lode.
The shaft was started in slate but at 125 ft. struck the altered green-
stone. At the 500-ft. level it required a crosscut 75 ft. long to the
vein, and below there was in very hard greenstone.
Levels were run but details of these are lacking except for the one
at 500 ft. Here, after the crosscut was run, drifts were extended
north and south a total length of 700 ft. An ore-shoot 114 ft. long
was claimed by the promoters on that level, but on account of a heavy
flow of water encountered there, the level was closed by bulklieading
and the shaft was continued to a depth of 770 ft., where work appears
to have stopped, without any record of production.
Argonaut Mine
History
Originally known as the Pioneer, this mine was first worked in
1850, but received little attention for many years; in 1876 the depth
reached was only 150 ft. and there was no mill, although the adjoining
Kennedy workings had been brought up to the property line, where
the Pioneer ore-shoot was known to be 18 ft. wide. Most of the early
work on the Pioneer was through an adit on the northern end of the
claim. Argonaut Mining Company was incorporated in 1893. Oper-
ation has been continuous since except for interruptions caused by
fires. In the sping of 1919, one started which was not brought under
complete control until the lower workings of the Kennedy and Argo-
naut had been flooded. This caused a loss of a year's time. Again, on
August 27, 1922, a fire from some unexplained cause began near the
3350-ft. level and caused the loss of 47 lives on the 4650- and 4800-ft.
levels. Milling of ore was interrupted again for about a year at that
time.
Production
The total production reported by Argonaut Mining Company has
been about $19,000,000. The tonnage of ore handled yearly since 1910
(except for 1920, 1921 and 1923) has been from 62,000 to 91,000 tons.
MOTHER LODE GOLD BELT 63
The best section of the mine was between the 3400-ft. and 4800-ft. levels,
where mining between 1914 and 1920 yielded ore which averaged from
$10 to $13 a ton. The average value both before and since that period
has been lower; a total of 914,466 tons of ore yielded $7,702,705
between 1913 and 1926. The production until 1932 has been entirely
from the Pioneer claim. Dividends paid have exceeded $3,000,000.
Geology
The geology of the upper one-third of the mine has been described
in past publications of both the State Mining Bureau and U. S. Geo-
logical Survey, which both stated that the vein occupied a fissure
apparently opened by a reverse fault in which the hanging wall had
been thrust up about 125 feet as indicated by displacement of the
Mariposa slate in the raise from the 470-ft. level to the old Pioneer
adit. Here should be mentioned the argument of Kennedy Extension
Mining Company in their suit with the Argonaut Mining Company.
About 1200 ft. in depth on the Argonaut fissure, a vein branched into
the hanging wall. The former company contended that this was the
older vein, which had been displaced about 700 ft. by normal faulting
as measured along the Argonaut fissure. The plaintiffs lost this suit.
The upper part of the vein to a depth of 290 ft. is in altered green-
stone, which has been classified variously as diabase, meta-andesite and
augite-melaphyre tuffs and breccias. Near the vein the greenstone has
been rendered schistose, and is locally termed amphibolite schist, a term
sanctioned not only by local usage but by geologists. Knopf prefers
to accent the changes in the greenstone due to hydrothermal alteration,
and points out that it is merely a facies of the greenstone. He found
much ankerite in it. From 290 ft. to about the 470-ft. level, the vein
traversed a narrow belt of Mariposa slate, and from there to 2500 ft.
deep was on or near the contact with Mariposa slate footwall and the
schistose altered-greenstone hanging wall. From there downward for
the most part the footwall country rock is hard gray schist, but
with a casing of black slate between it and the vein, and the hanging
wall is Mariposa slate. Where seen on the 4800-ft. level the slate
casing on the footwall was 10 ft. thick but in places is from 20 ft. to
40 ft. thick, varying with the weaving courses of the footwall contact
and the strike of the vein. On the 4350-ft. level the vein strikes
N. 18° W. and dips 63° northeast, with slips in both the walls about
parallel to the strike of the vein, but those in the hanging-wall slate
dipping about 80° northeast. On the 4500-ft. level the footwall con-
tact strikes N. 20° W. and dips northeast 60° to 63°. On the 4800-ft.
level the shaft crosscut to the vein crosses a pronounced slip with hard,
blocky gray schist on the hanging-wall side and slate on the footwall.
This slip is 125 ft. east of the true footwall, strikes N. 30° W. and dips
75° northeast. The vein, close to the footwall, has the normal strike
of about N, 18° W. and dips 60° northeast. To properly correlate the
geology of the Argonaut and the neighboring Kennedy on the north, it
should be remembered that the Argonaut has the main footwall vein
only, while in the Kennedy the breaking away of an immense horse
of rock led to the formation of a hanging-wall vein also. Sills of
greenstone, now standing nearly vertical, and entirely altered to schist,
64
AMADOR COUNTY
MOTHER LODE GOLD BELT 65
occur within the Mariposa slate and on certain levels, as a result, the
immediate hanging wall is greenstone and the footwall slate, as on the
3700-ft. level.
On that level the fissure was seven to ten feet wide and was one-
half filled with gouge and half with quartz. Between the 3600- and
4200-ft. levels, because of its north pitch, the north ore-shoot was in the
Kennedy, then returned to the Argonaut. On the 4200-ft. level the vein
was 20 feet wide ; on the 4350-ft. level it was 30 feet wide, and continued
wide in the south drifts in the deeper levels. Though most of the earth
movements have resulted in crushing the slate, the footwall schist is in
places shattered, and traversed by numerous quartz veinlets and occa-
sional slips about parallel to the main vein, the schist being reduced
nearly to gouge along these slips. The complete tracing out of the faults
in this or any of the other large mines on the lode would require careful
study at frequent periods over a number of years as the development
work went on. Besides the pre-mineral strike fault of the lode, and the
accompanying slips, there have been important oblique faults in the
Argonaut property, and post-mineral faulting within the vein. The
4500-ft. north drift 150 ft. south of the Kennedy line showed the vein
15 ft. wide with a width of six ft. next the hanging wall dragged down.
On the south on many levels the ore had been considered as bounded
by an oblique fault. This strikes northwest and its trace on the plane of
the vein dips 70° to 75° northeast, judging from the positions where
it was encountered on many levels. On the 4500-ft. level, about 200 ft.
south of the shaft crosscut, there was a length of about 200 ft. of broken
and crushed ground as a result of this fault. On the 4650-ft. level,
the vein was stoped 480 ft. in length when the crushed ground was
encountered. This extended for 75 ft., and ore was found south of it,
showing, when visited, 25 ft. of quartz of which the hanging-wall part
was solid white quartz, with the best ore consisting of a few feet of
ribbon rock on the footwall side. On the 4800-ft. level the vein
widened rapidly south of the region where the fault had been found on
the levels above. From a width of a few feet on the north, the vein
increased in width to 60 ft. on the south, and there was stoped 30 to
60 ft. wide. The stope length on this level was over 1000 ft. On the
4950- and 5100-ft. levels the vein is reported much narrower, and the
ore-shoot has apparently shortened and become flatter, approaching the
shaft, which is in the hanging wall of the vein. The manager reported
also a lower average grade of ore and ground increasingly hard to hold
open, resulting in an operating loss in 1926. The ore conditions did
not improve materially again until the 5550-ft. level. Here a junction
of two veins gave a large, low-grade quartz body on the north. Some
ore was found on the south, however, this being the top of a new ore-
body. On the 5700-ft. level, the north drift showed ore from 6 to 17 ft.
wide for a length of 200 ft. up to the Kennedy line. In the south drift
on this level, three ore-shoots, 158 ft., 235 ft., and 170 ft. long respec-
tively, varying from 5 ft. to 12 ft. in width and from $3 to $12 a ton
in value, were found, the last still showing in the face. At the time
of \dsit in 1932 the 5800-ft. level had been opened for 1100 ft. and the
ore being mined from day to day from both drifts showed many vari-
ations, but held up well in value on the north shoot.
^~"*^^^ PHYSICAL SCIENCES LIBRARY
UNIVERSITY OF CALIFORNIA
DAVIS, CAUFORNIA 95616
66 AMADOR COUNTY
The recent work in the Argonaut has given such encouraging
results that at the middle of 1934 the operators were optimistic about
the future and were planning prospecting work to determine the pos-
sibility that hitherto unsuspected ore reserves might exist in the unde-
veloped section above the present bottom.
The winze from the 5500-ft. level, 300 ft. south of the shaft, has
been deepened and levels have been opened at 5500, 5700, 5800 and
6000 ft. inclined depth. Late in June, the 6000-ft. level had been
drifted 950 ft. and the 5800-ft. level 600 ft.
The upper ore-shoot, which had been the mainstay of the mine for
so long, split into two branches near the 5400-ft. level, and these were
worked separately below there. The southerly limit of this ore on the
5700-ft. level was 500 ft. south of the winze. From there the south
drift was advanced on the footwall side, and at 250 ft. a crosscut
was run toward the vein, entering a section of faulted ground carrying
some good ore in the drag. The fault conditions at that time were not
understood. Later work brought out the fact that this crosscut was
in what is now called No. 3 fault, the southernmost of three such so
far discovered. No. 1 fault had been known since the early history of
the mine, and had generally been regarded as a boundary for ore.
This fault had a horizontal throw at the most of 80 ft. on the 2880-
and 3000-ft. levels, and has persisted with depth. No. 2 fault, south
of No. 1, was found to have a horizontal throw of 50 ft., or 80 ft. on
the drag on the 5700-ft. level, and No. 3, which is 200 ft. south of
No. 2, has about the same horizontal throw of 50 ft. Each of these
faults have moved the vein segments east, looking south. In June the
company reported 200 ft. in length of ore between No. 2 and No. 3
faults, and 200 ft. between No. 3 fault and the south face, where the
vein was 9 ft. wide. In this drift the vein was reported from 9 to 16
ft. wide. The grade of ore in this shoot so far is reported about the
minimum that could have been worked at the old price of gold, i.e.,
$6 to $7 a ton.
On the 6000-ft. level, the assays in the region of the old ore-shoot
are low-grade, but in a raise which was 40 ft. above this level in June,
1934, some very good ore was being found. This was 9 ft. wide and
shows strands of heavy sulphide (pyrite and galena chiefly), suffi-
cient to raise the sulphide content far above average. Ore recently
has been coming from levels between 5500 and 6000 ft.
A crew of 225 men in all was employed in 1934 up to the time of
the strike, October 2. About 180 of these were working underground.
The mill has been crushing 8000 tons a month. There does not appear
to be much change in the character of ore at this depth except as noted
on the 6000-ft. level. About 150 tons of sulphide concentrate is pro-
duced monthly. Both walls in the bottom are still reported to be Mari-
posa slate.
A storage battery locomotive, hauling six 1-ton cars, has been put
in use lately on the 5500-ft. level between the winze and main shaft.
An Eimco mucking machine (the first used in a Mother Lode quartz
mine) has also been installed and has been operated chiefly in drifting
on the 6000-ft. level.
MOTHER LODE GOLD BELT 67
Ore
The ore is generally best within a few feet of the footwall where
it is of a ribboned structure which indicates repeated reopening move-
ments and filling along that wall. Specimen rock is found at times.
Some of the ore in the south shoot which had the appearance of massive,
barren quartz gave surprisingly high assays. The ore has of course
considerable admixed black slate as it goes to the niill, but due to the
width of the quartz vein in this mine the proportion is less than in
many cases where stringer leads are mined. Ore has remained free
milling to the great depth reached, in the sense that most of the gold
is released by proper crushing and can be saved by amalgamation.
In 1931, when 61% of ore came from the 5700-ft. level and 32% from
the 5550-ft. level, the concentrate formed 2.4% of ore milled, and
yielded 22% of the gold saved and 28% of silver. The gold content of
concentrates has ranged from 2.6 oz. to 5 oz. per ton, varying with the
grade of ore. As the grade of ore decreases the amount of silver
in the concentrate, never important, appears to increase to about 1 oz.
per ton, possibly due to a little higher proportion of silver in the
sulphides of the wall rock, of which more is likely to be milled when
the vein narrows. Pyrite is by far the most plentiful sulphide.
Galena is always favorably regarded, as is also arsenopyrite, Pyr-
rhotite, chalcopyrite and tetrahedrite also occur sparingly. Three
periods of sulphide mineralization are noted; 'paint' sulphide, which
is worthless, another with a glossy look, is low grade. Over a long
period, there is no such thing as an average grade ore in these Mother
Lode mines. The paper average of $8.42 a ton for the Argonaut
between 1913 and 1926 on a total of nearly a million tons conceals
variations of several dollars a ton. As noted, ante, under Production,
the best ore found in large quantity, was between the 3400-ft. and
4800-ft. levels and averaged $10 to $13 a ton.
Mining Conditions and Methods
The inclined shaft of the Argonaut has three compartments, one
for manway, pipes, etc., and two for hoisting, each being 4 ft. 1 in.
by 5 ft. 9 in. in the clear. Dip of the shaft is 63° to the 1650-ft. level.
The vein was flat for the first few hundred feet from the surface and
there lies under the shaft which crosses it at the 290-ft. level. From
the 470-ft. level downward, however, the vein steepened so that the
shaft crossed it again at 1650 ft. and below there is in the hanging
wall. From 1650 ft. to 4050 ft. the shaft has an inclination of 57°,
then steepens again to 63°, so that it remains at about a constant dis-
tance from vein in the deeper levels; the crosscuts from shaft to vein
are 215 ft. long on the 4950-ft. and 5250-ft. levels. The nature of
formations required heavy shaft timbering and 'Oregon pine' (fir)
20 by 20 inches was used for most of it, but lately somewhat smaller
sizes have been thought sufficient, where the ground is not hea^^ or
broken. This shaft is 5700 ft. inclined depth. On the 5550-ft. level, 225
ft. south of the main shaft and in the footwall, a station was cut,
another hoist installed and sinking was resumed, with the 6200-ft. level
as an early objective, although the hoist will permit going much deeper
if desired. Levels are 150 ft. aparL
68 AMADOR COUNTY
The ground is heavy, particularly along the vein, so that very little
space can be left open while stoping. Parts of shaft crosscuts in hard
schist are the only exceptions to the heavy timbering which forms one
of the principal items of mining expense. Drifts to prospect the vein
and prepare for stoping are usually run one set wide along the foot-
wall with a pillar left along the hanging wall, which is later taken from
the next lower level. Posts of drift sets are of local round pine, from
12 to 24 inches in diameter and caps are 12 in. by 12 in. Posts are
spread to withstand side pressure. In lagging, space is left to permit
gouge and fine rock to squeeze out and relieve pressure. Modified
square-setting with waste filling was standard practice until 1925-
1927 when a form of vertical slicing was tried. This had to be
abandoned and the old method resumed. In these square sets round
posts 14 in. to 18 in. in diameter, caps 12 in. by 12 in. and girts from
8 in. to 12 in. are used. Waste filling taken from chambers in the
walls is kept up to within one set of the stoping work. Even with this,
the ground will soon begin to squeeze. The heavy ground discourages
much advance development, and induces as rapid stoping as possible,
once a block is opened. These ore blocks are generally worked in
sections about 100 ft. in length above the drift at a time, with ore
chutes 25 ft. apart.
Ore is drilled with 1-inch stopers, blasted with 30% gelatin dyna-
mite, and hand trammed to shaft ore-pockets in 1-ton cars. Skips
running in the main shaft are operated in balance so far as possible,
by a geared hoist having drums 8 ft. by 47 inches using wire rope
1^ in. in diameter, and made of 6 strands of 19 wires each of crucible
steel with a hemp center. Power is furnished by a 500 h.p. 60-cycle,
8-phase induction motor, operating at 440 volts, with a master switch
and liquid rheostat. Though the hoist is of 72 cubic feet capacity, the
average load of ore hoisted in 1931 was 7464 pounds.
Milling Methods, Recovery
Ore generally, because of its friable nature and the blasting
practice, reaches the surface grizzley rather fine ; oversize plus 2^-inch,
is broken in a jaw crusher in the headframe, is weighed and taken to
the mill bins by a tramway. These bins hold 2200 tons. Ore is fed
by Challenge feeders to the 60 stamps, weighing 1285 lb. each newly
shod. Battery screens are of No. 30 brass wire with openings of 0.0277
inch. Stamps drop 8 inches 96 times a minute, and discharge averages
7 inches high. These stamps were made in 1916 by Knight & Com-
pany of Sutter Creek. An 85 h.p., 60-cycle, 440-volt induction motor
is used for each 20 stamps.
Some years ago (1922-1928) this company installed Dorr classi-
fiers, Deister and Wilfley concentrators, cones and tube mills for
regrinding. Lately they have taken all this equipment out of use and
have returned to the simpler flow sheet. After inside and outside
amalgamation, pulp passes to spitzlutte, one for each 5 stamps, and
each of these deliver different sized products to each of two improved
iron-frame Allis Chalmers vanners. Overflow from spitzlutte goes to
a Callow cone from which underflow passes to a third vanner ; three
vanners thus handling the product of each 5 stamps. Vanner tailing
MOTHER LODE GOLD BELT 69
and overflow from cones pass through a pipe to the cyanide plant of
Amador Metals Reduction Company. Vanners require about 1 h.p.
each. Concentrate is shipped for smelting. In the long run over a
period of many years, the mill extraction under the method described
does not appear to have varied materially from the more elaborate one
using tube mills, late model concentrators, etc. Recovery in the mill
has ranged from below 84% to 91%. Both of these extremes were
had when using the tube mills. When using vanners, the average
extraction was from over 85% to 89%. Metallurgists are prone to
account for this condition by assuming that foremen and millmen
accustomed to nothing but vanners cannot or will not get maximum
results with machinery which requires more attention and greater skill.
But the difficulty is also largely due to the association of most of the
gold lost with carbonaceous slimes. In the cyanide plant of Amador
Metals Reduction Company the sand and slime are first separated in
a Dorr classifier, and are separately cyanided, as described in more
detail in the chapter on Metallurgy.
Costs for 1931
Mining cost, per ton mined (operating costs) :
Item Amoutit
Mining $1,913
Development 1.033
Hoisting .511
Surface .448
Repairs, maintenance .859
Total $4,764
Distribution of mining costs (operating) :
Atnount,
per ton
Account mined
Labor $3,307
Timber .353
Power and water .336
Explosives .139
Hardware and supplies .437
Insurance .015
Accidents .111
Freight, etc. .066
Total $4,764
70 AMADOR COUNTY
Distribution of milling costs :
Amount,
per ton
Account milled
Power, water, lights $0,196
Labor .266
Treatment of concentrate .349
Hauling .024
Hardware and supplies .081
Insurance .015
All other expense .026
Total $0,957
Recapitulation :
Mining cost, operating $4,764
Milling cost, operating .957
General .488
Total $6,209
Ballard Mine (Ballard and Martin). Mrs. Maria Ballard, owner.
Leased to John F. Ratto with option to purchase. Comprises E^ of
AV^ of Sec. 14, T. 8 N., R. 10 E., containing 160 acres under agricul-
tural patent.
Although considerable work was done in early days here, including
the sinking of several shafts and some stoping there is no available
record of results. In 1928, Lopez Mining Company put a 10-stamp
mill at the main shaft and reopened that shaft and the 200-ft. level,
extending the latter south. They failed and the property lay idle until
late in 1932, except for some shallow work by lessees. Early in
February, 1933, about 10 men were employed. The south drift on the
200-ft. level was then 175 ft. long and being extended ; on the north,
an old drift had been reopened on the same level for 80 ft.
The west vein is reached by a crosscut 430 ft. long from the shaft
on the 200-ft. level. The workings are in Mariposa slate. An ore
shoot about 50 ft. long is claimed in the south drift, near the crosscut.
It has not been explored except on this level, so far as known. Farther
south, the drift was turned away from the apparent course of the vein,
as indicated by holes lately put in the west side of the drift. The
quartz so revealed is to be prospected. The Spanish shaft is 70 ft.
deep and is about 150 ft. ahead of the south face ; and some large out-
crops of quartz could be prospected at depth by running this level
350 ft. south. On the north, 500 ft. from the shaft crosscut, an old
adit cut a vein 16 ft. wide which is said to offer inducements to carry
the north drift ahead on the 200-ft. level to prospect it.
A light 5-stamp mill with one concentrator was being completed
at time of visit, on a hillside 600 ft. south of the main shaft, and
above it. This will permit mill tests of quartz from nearby outcrops
and from old shafts sunk years ago. At main shaft there is a portable
compressor, two 4-cylinder gasoline engines and a single drum hoist.
Early in 1934, a decision in favor of Ratto was rendered in a
quiet title action against H. L. Berkej' and Ballard-Plymouth Gold
Mines Co.
MOTHER LODE GOLD BELT 71
Bay State Mine, four miles north of Plymouth, was opened in the
early 1890 's, the shaft having been 300 ft. deep in 1892. Water was
struck in such quantity that the drifts on the 300-ft. level were closed
with concrete bulkheads in 1893, and shaft-sinking was continued.
A 10-stamp mill was erected and early in 1895 was running steadily
on ore stoped between the 600-ft. and 500-ft. levels. Late that year
ore was being mined from four places on those levels and was said to
be pajang a little more than expenses. This ore was stoped from the
600-ft. to 400-ft. level by Bay State Mining Company. The total
reported production from 1892 to 1897, inclusive, was about $34,000.
This company quit work at 750 ft. in depth about July, 1897. Work
was resumed in 1899 but no more production was made until 1900
when Globe Mining and Milling Company took control. From then
until 1905 production was small and irregular, amounting to about
$24,000 in all. The main shaft reached a depth of 1065 ft. on an incline
of 81°. and was 44^ ft. bv 9 ft. in the clear. Levels were run at 300,
400, 500, 600, 750," 830 and 1030 ft. The last production was in 1909
but the exact amount is unknown as it was worked in connection with
the Rhetta.
The shaft was sunk between the West and Middle veins, and the
principal work was on the latter, also called the Bay State vein. The
Kretcher or West vein was reported to have been reached by a crosscut
350 ft. long from the 300-ft. level, and by longer crosscuts on the
750-ft. and 1030-ft. levels. The Bay State vein was opened for a
length of about 300 ft. on each side of the shaft on the 1030-ft. level,
and Kretcher vein was prospected for a length of 200 ft. in each direc-
tion on 750-ft. level, also 250 ft. north and 300 ft. south on 1030-ft.
level. If any ore was stoped from the latter, there is no separate
record of it at hand. It is stated that a raise was run from the
1030-ft. to 700-ft. level on this vein. The veins are said to average 4 ft.
thick but in places reach 12 ft. in thickness. It has been stated that
work in 1899 on the C. Kretcher property south of the Bay State indi-
cated that these two veins join there. The strike of main vein is N. 15°
W. and dip'76° E.
There is also stated to be an east vein, called the Vaughn, which
was struck in a crosscut from the bottom level, but water caused trouble
at this face also. Definite details are lacking, but considerable low-
grade rock is claimed to exist in the mine.
There is no equipment on the property. It is on an agricultural
patent.
Late in 1934, this mine was being unwatered by AVest American
Consolidated Gold Mines.
Bellwether Mine, one-half mile north of Jackson on an agricultural
patent 600 feet by 3200 feet on the East (or Zeila) vein, was developed
by Bellwether Mining Company between 1895 and 1900. Previously
it had been prospected by several shallow shafts, the deepest 180 feet
deep. The later work included an inclined shaft 320 feet deep with
crosscuts and drifts to prospect the wide vein, which is the east or
hanging-wall branch of the Mother Lode, carrying ore similar to the
Zeila Mine, on the south. On the 282-ft. level, a crosscut was run east
130 feet, and it was claimed the lode was found to be 85 feet wide and
was reported to show fairly good assays for a width of 40 feet. Noth-
72 AMADOR COUNTY
ing more is known of the claim, which later w'as bought by the Ken-
nedy Mining and Milling Company.
Bunker Hill Mine {South Mayflower)
History and Production
Originally called the Ranchoree or Rancheria Mine, under which
name work started in 1853, the Bunker Hill claim was first worked
by open cut, then opened through the south shaft, 350 ft. from the
Little Amador line. In 1863, Bunker Hill Quartz Mining Company
was organized and the south shaft was sunk to 450 ft. on the incline
in the next few years. Later the north shaft was started 360 ft. from
the first and both were in use many years. Soon after the beginning
of work a 12-stamp mill had been built. The ore in the upper workings
was often rich, as between the 170-ft. and 270-ft. levels, where it is
said to have yielded $50 to $75 a ton. Most of the ore came from the
vein in slate, although a drift on the hanging-wall vein in greenstone
is said to have yielded in one place "$2,000 in gold for every barrel
full." At 350 ft. the vein was reported 6 ft. wide and yielded $10 a
ton with a working cost of $7 a ton. A 40-stamp mill and a chlorina-
tion plant were built in 1880, and the next 10 years were devoted to
working out the ore in the Mariposa slate. By 1888, the north shaft
reached a depth of 800 ft. on the incline (680 ft. vertical). The mill
was crushing an average of 99 tons a day. Mining cost $3.35 a ton,
milling 60 cents and chlorination treatment of sulphides (then 2%
of ore) $14.61 a ton. Knopfs quotes Elisha Hampton, former Super-
intendent, as saying the mine produced $1,272,000 prior to 1891. In
that year only $7,386 was taken out.
By 1893, the mine had been idle long enough to permit the main
shaft to cave and the plant to deteriorate. It was re-named the South
Mayflower and a reopening was begun, the Mayflower and Nevada,
claims being consolidated with it about this time. In 1894 the group
produced $30,000 and in 1895 a claim on the hanging-wall greenstone
known as the East Mayflower yielded $5,000. In 1899, Bunker Hill
Consolidated Mining Company was organized and worked steadily until
late in 1922.
At 800 ft. in depth, the principal channel of mineralization entered
the greenstone and the larger part of ore thereafter was 'grey ore,'
entirely different from and much lower in average gold content than the
slate-quartz ore mined above. During this period, 887,585 tons of ore
yielded $3,834,550. The last production amounted to $5,446 in 1925.
This gives a grand total of $5,154,382. During 11 years prior to Sep-
tember, 1916, this mine paid 123 dividends, said to have amounted to
about $1,000,000 or about 5 times the amount of the capital stock
($200,000 par value). Assessments were levied after 1916 but their
amount is unknown. Profit stopped with ore at $4 a ton.
Mine "Workings and Geology
The most profitable operations at this mine, as at most of those on
the lode, were on orebodies in the black Mariposa slate at the metande-
site contact, known here as the hanging-wall vein or Bunker Hill Vein.
lU. S. Geol. Survey, P. P. 157, p. 55.
MOTHER LODE GOLD BELT 73
The footwall of this vein was usually the soft, swelling slate, and hang-
ing-wall greenstone (meta-andesite) although the wall rocks were in
places both slate, or the footwall greenstone, due to the vein crossing
interlayered bands of slate and greenstone. The work between the
1950-ft. and 2800-ft. levels is on the hanging-wall vein, and this same
vein was being prospected in the winze workings below 2800 ft., where
the hanging wall is hard meta-andesite, in places altered to schist. The
ore in this vein is a black gouge ore with quartz stringers. This vein
Avas stoped above the 2400-ft. level, where the orebody was of a max-
imum length of 800 ft. and a maximum width of 10 ft., averaging
five to six feet. There is still considerable low-grade ore left above the
2800-ft. level.
The upper slate orebody, as noted above, had been worked out by
1891 down to the 800-ft. level. The 'grey ore' body was first found
on the 1400-ft. level and was worked for a length of 420 ft. there,
extending 280 ft. south of shaft. Where first found it was 40 ft. west
of and about parallel to the Bunker Hill vein. The ore lenses occupied
a wedge-shaped section, entering the hanging-wall vein on the north.
It had a maximum length of 850 ft. and average width of 30 ft. but
was in places 125 ft. wide. It was worked down to the 1950-ft. level.
This 'grey ore' was formed by the hydrotliermal alteration of the
greenstone. It contained up to 4% of sulphides principally pyrite.
It furnished the bulk of profitable tonnage during the last company's
operations.
Most of the later work was north of the shaft, and below the
1950-ft. level on the hanging-wall vein. . This vein here is a crushed
gouge of slate and quartz stringers with some large bodies of low-grade
massive quartz. In the 2200-ft. level north drift there was a width
of 30 ft. of barren quartz on the hanging wall, with 4 ft. of ore on the
footwall, the two sections being separated bv a gouge seam. From the
1950-ft. level to 2800-ft. level, lengths of from 1450 ft. to 1778 ft. (by
co-ordinates) were drifted northward on the hanging- wall vein, all
the later operations having been devoted to a search for more high-
grade ore in it. At the time of last visit the 3200-ft. level had been
run 100 ft. each way and the 3400-ft. level 350 ft. north and 100 ft.
south on the same vein. It was found to vary from a few inches to
over 30 ft. in width. Near the shaft this gouge of slate and quartz
occupies what may be a spur in the footwall of the main Bunker Hill or
hanging-wall vein, the junction of the two being 860 ft. north of the
shaft. The large 'grey ore' body occupied the wedge between them.
The hanging-wall vein .showed a length of 800 ft. and an average width
of 5 to 6 ft. of material where opened on the 2400 ft. level, but the
assays generally on this vein between the 800-ft. and 2800-ft. levels
were too low to make ore, and much of it was left unstoped.
Ore and Concentrate
About two-thirds of the gold saved from ore and "near ore"
mined in later years, was from concentrate. Over a period of several
years the concentrate averaged 3.14% of ore and yielded an average
of $77 a ton. The recovery was 80% to 82% before a ball mill was
added to regrind sand tailing. This was used only about 2 years.
For some years a cyanide plant was operated on tailing, but the
saving with this went as low as 25 cents a ton.
74 AMADOR COUNTY
Mining and Milling
On the Bunker Hill vein square-set timbering was used with filling.
Timbering cost 30 cents a ton. On the 'grey ore bodies' the shrink-
age system of mining was followed, using some stulls and butt
caps. The average production of ore per man-shift for underground
workers was 1| tons and for the entire crew about 1^ tons during
years of full operation. The total operating cost then was $3.34 a ton,
of which $1.66 was for mining, 25 cents for treatment and 45 cents for
development.
There was a 150-gallon electrically driven pump on the 800-ft.
level, one of 50 gallons capacity on the 2100-ft. level and an air driven
pump on the 2400-ft. level. About 50 skips of water a week was
hoisted from the bottom of the shaft (2800 ft.) and about 10 skips a
day from the winze (3440 ft.).
Ore was hoisted in 2|-ton skips by a double-drum hoist with
300-h.p. motor. The reduction plant had a simple flow sheet, equip-
ment having been as follows : Knight crusher, forty 1050-lb. stamps,
24 vanners, 5 other concentrators, and 5 ft. by 6 ft. Hendy ball mill.
Milling practice when at full capacity in 1915-1916 included stamping
and amalgamation, followed by concentration on Deister tables after
which the sands were ground in the Hendy mill and the entire pulp
was concentrated on the Frue vanners.
Centennial claim is in W^ of SWi Sec. 13, T. 7 N., R. 10 E., a little
east of the Dry Creek claim of Detert Group. The vein is in the altered
greenstone of the hanging wall of the Mother Lode. An inclined shaft
was sunk in 1900 to a depth of 630 ft. It passed into the footwall and
crosscuts were run to the vein on the 150-, 250-, 350- and 630-ft.
levels. Width of the vein is reported from 2 to 18 ft. There is no
record of production.
Central Eureka Mine
History and Production
Originally located as the Summit Mine in 1855, the claim yielded
a 'chimney' of ore at a depth of 165 ft. which produced $30,000.
Two shafts were carried down to depths of 550 and 700 ft. respectively,
without any more production, and work had been stopped by 1875.
The mine lay idle thereafter until 1896 when Central Eureka Min-
ing Company began operations. The later history has been highly
interesting. The south shaft, which was 700 ft. deep when this com-
pany started, was sunk to a depth of 2500 ft. by 1907. A 10-stamp
mill was built in May, 1900, but production had started before this,
some ore having been crushed at the Zeila mill. During this period,
ended in 1907, the operations were on the hanging-wall vein between
1000-ft. and 2500-ft. levels, but a little ore was taken from the inter-
mediate vein. Very good profit was realized from this section of the
mine, but the best ore had been mined by 1907.
After closing down in that year, the mine was reopened in July,
1908, but for the next ten years results were discouraging. The extrac-
tion dropped to an average below $4 a ton and many assessments were
levied. The retiring directors in April, 1916, concluded the mine was
exhausted, and wanted to quit. Conditions at the time appeared to
MOTHER LODE GOLD BELT 75
warrant this. The shaft had been sunk an additional 1000 ft. and for
several years the ore-shoots had been shortening and of low grade. The
plant was getting old and the shaft was in dangerous condition, with
the skip still being run on strap iron. Due to the convergence of the
end-lines in the direction of the dip, the length of the holdings along
the contact vein was shortening on each successive level. All 3 veins
had been mined and had proved disappointing. But although the
48th assessment had been levied, it was fortunate for all concerned
that the new directors determined to continue.
Early in 1919, the 3500-ft. level was reached. The shaft crosscut
on this level showed signs of ore. On the north, also, a good shoot was
found and was stoped to the 3425-ft. level. In a winze below the
3500-ft. level a sub-level was turned and was run both ways in fine ore.
Then followed a period of 11 fortunate years during which the shaft
was carried to a depth of 4965 ft. on the incline and every year wit-
nessed the payment of dividends. During this period the adjoining
Old Eureka mine comprising the Amador, Maxwell, Alpha and Rail-
road claims and 136 acres of adjoining land was bought and paid for ;
a new steel head-frame was erected and many other replacements and
improvements were made.
Below the 4500-ft. level the ground was found to be badly broken,
and shaft and drift maintenance and other underground repairs cost
more than breaking ore. These conditions, together with a lowering
of gold content in the ore, led to a substantial operating loss during
the calendar year of 1930. The lower workings of the Central Eureka
were therefore abandoned and all pipe, rails, pumps, etc., were removed
from the deeper levels and the track in the shaft below the 3900-ft.
was taken up. This closed, at least for the time being, the productive
history of the Central Eureka or Summit claim. Since then attention
has been turned to the development of the Old Eureka section, sep-
arately described under that name.
The production of the Central Eureka claim has been about as
follows, including the year 1930:
From 1869-1871 $30,000 (ore $16 to $32 a ton)
From 1896-April, 1901 223,470 (tonnage not known)
April, 1901-1907 1,945,000 from 287,175 tons
July, 1908-April, 1918 923,455 from 269,056 tons
April, 1918-end of 1930— 5,200,000 from @ 607,000 tons
Total— $8,321,925
Dividends paid up to April 25, 1929, amounted to $3.21 a share
or a total of $1,263,973. Total assessments levied up to 1929 amounted
to $500,000.
Since 1930, the production has been coming from the Old Eureka
section of the property.
Mine Workings
The Central Eureka shaft is 4965 ft. long on an average dip of
70°. It struck the hanging-wall or east vein at 500 ft. and followed it
to about 2000 ft. in depth, where it passed into the slate in the foot-
wall of that vein. It cut the intermediate vein below 2700 ft. and
76
AMADOR COUNTY
25 ft. below the 3425-ft. level entered the altered andesite, but below
4000 ft. again entered the slate. The footwall is black Mariposa slate
nearly all the way. This shaft, like many other old ones on the Mother
Lode which were sunk to follow the vein, has been expensive to keep
open. The swelling footwall shoves shaft timbers out of line. Below
the 4500-ft. level, espe-
cially difficult conditions
were found, with frac-
tured and moving
ground. From the 4500-
ft. level down, the shaft
sets are of spruce logs 2
ft. in diameter with
jacket S3ts behind them.
These jacketed sets were
tightly lagged to keep
the ground from run-
ning. The shaft has
three compartments each
3 ft. 9 in. by 5 ft. in the
clear. Two are skip-
ways and one a man-
way. Skips of 3 tons
capacity operate on 52-
Ib. rails laid 27 inches
apart on the footwall
plates of the shaft. The
hoist in use was first
installed at the Gwin
Mine in Calaveras
County in 1900 and was
brought to the Central
Eureka in 1920 and re-
built. It is operated by
a 300-h.p. motor.
Central Eureka
shaft has been aban-
doned below the 3350-
ft. level. If experience
with the nearby Old
Eureka shaft is any
guide it will be only a
matter of time when the
lower part of the aban-
doned section and the
lower levels collapse be-
cause of hea^^ ground
pressure, if this has not already occurred. Levels were turned at inter-
vals of about 100 ft. to 200 ft. depending on conditions. The deepest
level was at 4855 ft. (on 70° incline). From 1919 to 1930 the mine
was deepened from 3500 ft. to the bottom with levels at 3500, 3600,
3760, 3900, 4100, 4250, 4400, 4550, 4700 and 4855 ft. During this
Headframe, Central Eureka Mine, showing skip
runway In the form of a bridge truss.
Photo by C. A. Logan.
MOTHER LODE GOLD BELT 77
time the South Eureka ground was under option and was prospected
on the 3350-, 3900- and 4100-ft. levels. The 3900-ft. level was run
south 1180 ft. from the shaft, extending some distance into the South
Eureka, and a crosscut was run 740 ft. east in the slate from this
level through several vein formations and gouge seams, without finding
ore. The 4100-ft. level was also extended into South Eureka ground.
Due to shortening of the Central Eureka claim on the contact vein
with increasing depth, an account of the converging end-lines, the
purchase of the Old Eureka was important. The 4450-ft level was the
most important in the mine, but on this level and on the 4400-ft. on
the south end of the mine the ground became badly broken and had
much gouge. Yery heavj^ timbering was required in drifts as well as in
the shaft. Booms and lagging had to be used in places. On the 4855-
ft. level a crosscut was run 240 ft. east and this struck a large body
of 'gray ore' on which considerable prospecting was done, besides
which the footwall drift was carried north 800 ft.
Geology and Ore Shoots
The Mother Lode belt at the Central Eureka is about 1600 ft. wide
and composed mostly of Mariposa (Jurassic) black clay slate, in which
occur in the westerly or footwall section, several beds of andesite or
andesite porphyry. It is in that section that ore so far has been found.
This series of rocks dips east at a steeper angle than elsewhere on the
lode. The principal vein worked in the earlier operations was the
so-called hanging- wall or east vein, which had an andesite bed for its
immediate hanging wall. The ore shoot on this vein extended from
near the 1000-ft. level to 2540-ft. level, was from one to 12 ft. thick
and had its greatest stope length about the 1500-ft. level. The exact
tonnage from this shoot is unknown but was probably about 300,000
tons which was worked with results noted (ante) between 1896 and
1907, averaging $7.16 a ton up to 1905.
Between the 2540-ft. and 3425-ft. levels, the mine showed most of
those aspects which conservative engineers use as criteria of a worked
out property. The most of rock milled did not pay expenses, and if
ore were encountered it soon gave out. Contact, footwall and inter-
mediate veins were all explored and mined with similar discouraging
results. The average yield between 1908 and 1919 was only $3 to $4 a
ton. The size of bodies of even this grade kept decreasing. The east
vein was mined down to the 3350-ft. level with unsatisfactory results.
The intermediate vein also fell off in grade and the stope length short-
ened below 3000 ft. A crosscut was run 774 ft. east on the 700-ft.
level without finding ore ; and on the 1800-ft. level, a footwall crosscut
717 ft. long gave no encouragement.
The first indication of better times was the occurrence of small
lenses of good ore in the footwall gouge on the 3350-ft. level. Good
ore two ft. wide was found on the 3425-ft. level. On the 3500-ft. level
in 1919 a contact between slate and 'greenstone' (altered andesite)
was struck 28 ft. southwest of the shaft. This contact was followed
215 ft. south by drifting and revealed from 2 ft. to 5 ft. of rock
and ore assaying $2 to $7 a ton. A crosscut run 30 ft. west from, this
drift revealed 3 ft. of fine ore. The main crosscut westward from
the shaft was in crushed slate and quartz stringers. In this crosscut,
78 AMADOR COUNTY
33 ft. west of the greenstone contact, quartz was cut on the north side
and on being followed it proved to be a good ore-shoot. From this
north drift, a crosscut northeast to the 'greenstone' contact failed to
show ore ; but 30 ft. farther north, another hanging-wall crosscut struck
a small ore-shoot. In the floor of this north drift on the 3500-ft. level,
a winze was started and at a depth of 85 ft. drifts were turned. The
first 50 ft. on the north had an average width of 14 ft. and assayed $20
a ton ; for 80 ft. on the south it was even better. This ore was ribbon
rock carrying a good deal of pyrophyllite. Thus what appeared to
be two ore-shoots, separated by 160 ft. of low-grade vein filling, were
found. In depth, however, the south shoot pitched north and they
joined at the 3760-ft. level. On the 3760-ft. and 3900-ft. levels this
footwall ore-shoot (which is difficult to correlate with previous ore
bodies because of inaccessible workings, but is not believed by Albion S.
Howe to be in the same vein mined above the 2540-ft. level) was 340 ft.
long and averaged 9 ft. to 10 ft. wide, consisting of ribbon rock and
gouge on both walls.
The most important and productive level in the mine was at 4550 ft.
inclined depth on this ore-shoot. The shaft crosscut (running north-
west) crosses a width of 60 ft. on that level that should probably be
considered vein matter. North of this, the main vein (footwall vein
so-called) was a stringer lead of crushed quartz and slate striking N.
40° W. and dipping 71° E., and the orebody had an average pitch of
45° NW. in the plane of the vein. On the east side, a spur vein striking
N. 25° W. makes into the vein at this ore-shoot. This spur vein itself
formed stoping ground for a length of 165 ft. from its junction with
the main ore vein, which it entered about the center of the main ore
shoot, here having a length of 425 ft. In cross section, west to east, the
writer observed the following sequence in the stope above the drift :
high-grade quartz ore in black graphitic schist, perhaps a phase of an
altered dike; next, 8 ft. of quartz ore, on the hanging wall of which
appeared the point of a 'greenstone' dike, 18 inches wide, separated
from the ore by a small slaty gouge. This had on the east more of the
graphitic schist. Here we have a fine example of the occurrence of
an important orebody at a junction. Here the ore vein (footwall vein)
and the contact vein meet or are linked by veins like this spur.
Schistose altered greenstone appears close by in the footwall, and on
the hanging wall are layers of slate interbedded with greenstone dikes
or sills. A very rich streak of high-grade quartz, so finely crushed that
it could be rubbed to powder in the fingers, traversed the spur vein
diagonally to its junction with the main shoot. On the north and
separated from the main ore body by 130 ft. of low grade, a quartz
orebody 80 to 100 ft. long was found. This level yielded over 100,000
tons of ore, carrying $10 to $14 a ton. A width of 25 ft. was stoped
in places.
The broken, heavy and moving ground encountered first in the
south workings about 4400 ft. deep, passed downward through the
4700 ft. level station and the bins there were in it. It faulted the ore-
body farther north with greater depth. The increasing cost of work
when this cross fault entered the ore zone already crushed by subsidence
or tension Assuring from the hanging wall, and the lower grade of ore,
ended profits from this shoot on the 4855-ft. level. This vein gave
out on this level 800 ft. north of the shaft, according to Albion S. Howe.
MOTHER LODE GOLD BELT
79
- o
- f^
80 AMADOR COUNTY
Crosscuts were run to the hanging wall 'greenstone' on the 4855-ft.
level and one that penetrated it showed it to be crushed and badly
shattered. Next to the slate hanging wall this greenstone is well min-
eralized, and carries bunches and stringers of quartz. On the north
end of this level, 600 ft. to 700 ft. north of the shaft the 'gray ore'
formed in this greenstone is reported by James Spiers, superintendent,
to be 60 ft. wide. While it was prospected only at intervals, there
were indications of a large body of it which gave great variations in
assay returns. This body appeared to have its apex along the 4700-ft.
level and a little above it.
Milling, and Ore Characteristics
The 40-stamp mill has a capacity varying from 146 to 160 tons in 24
hours, depending on the condition of feed. The stamps weigh 1280 lbs.
each fully shod, drop 96 times a minute and crush ore through 24-mesh
screen. Concentrate is saved on Frue vanners. Kecovery has varied
from 89.37% to 94.31% of mill-heads since 1920. The latter figure was
obtained when mill heads averaged $13,148 a ton for a year, and was
probably due to the greater proportion of coarse free gold, as compared
to gold in sulphides. This proportion has varied considerably from
year to year, having been nearly 6 to 1 from 1920 to 1925, 4 to 1 in
1926 and less than 3 to 1 in 1930. Crushed ore, unavoidably diluted
by gouge and wall rock, lowered ore grades, and also recovery due to
loss of fine sulphides. The percentage and value of concentrate ranged
from 1.69% worth $107 a ton on the 3700-ft. level, to 2.8% worth $68
a ton at the 4700-ft. level. Tailing has varied in value from 64 cents
to $1.12 a ton.
Information Circular 6512 of the U. S. Bureau of Mines, written
in 1931 by James Spiers, superintendent of the mine, gives an excellent
account of mining methods and costs at this mine.
Chicago, Conville, Giant and Reeves (Bartlett, Accident, A & B)
claims are on the hanging wall side of the wide Mariposa slate belt a
little southeast of Plymouth. There is little available concerning the
results of work on them. The Chicago claim has a shaft reported to
be 400 ft. or more in depth. Some of these claims have been pocket
producers. The principal vein on the contact, with slate footwall and
amphibolite hanging wall, does not appear to have been productive.
A & B claim had a shaft 175 ft. deep, two crosscut adits and an
open cut 200 ft. long, run in search of pockets.
Creek Ledge prospect, a mile north of Plymouth on an agricultural
patent, has a shaft 100 ft. deep sunk on the vein between the slate
footwall and greenstone hanging wall. Vein varies from 4 ft. to 10 ft.
wide. Only about 50 ft. of drifting was done on the 100 ft. level. No
work has been done for over 20 years.
Detert Estate Group comprises 17 quartz claims in Sees. 11, 13, 14,
23 and 24, T. 7 N., R. 10 E., between Plymouth and Amador City,
belonging in whole or in part to the estate of the late W. F. Detert.
These claims, on which no work has been done in late years, were
gradually accumulated over a long period by the late owner, who has
left no record of the past operations, and apparently the only informa-
tion concerning them is that appearing in past State Mining Bureau
MOTHER LODE GOLD BELT 81
reports and the notes gathered for the present paper. Names of the
claims and acreages are :
Atlantic Q. M., 15.46 acres. California Q. M., 10.81 acres. Chili
Jim Q. M., 4.56 acres (f interest). Cosmopolitan Q. M., 15.90 acres.
Dry Creek Q. M., 5.5 acres. Eureka No. 2 Q. M. @ 10 acres. Gov-
ernor Bradford Q. M., 12.091 acres (| interest). Henry Clay Q. M.,
6.49 acres. Hercules Q. M., 15.59 acres. Joe Davis Q. M., 8.27 acres.
New London Q. M., @ 18 acres (^ interest). North California (Web-
ster) Q. M., 6.99 acres. North Eureka No. 2 Q. M., @ 5 acres. North
Henry Clay Q. M., 11.89 acres. Pocahontas Q. M., 10.25 acres (f inter-
est). Providence Q. M., 16.33 acres. South Cosmopolitan (Worley)
Q. M., 14.29 acres.
The California, also called the Potosi, was the earliest of these
mentioned. In 1867 it was said to have been worked since 1852 and
had a vein 4 ft. wide. It was equipped with a 16-stamp mill. In 1876
it was idle, the shaft having reached a depth of 200 ft. It is reported
locally that this claim produced $82,000 near the surface, but there is
no definite record to substantiate this. In 1880, a new company
repaired the mill, and the claim was said to have good ore. In 1884,
nine miners took the mine "on a lay" under which they were to be
paid wages if the company took the property back within a certain
time. They made three 'crushings' of ore which averaged according
to report $3.50 a ton. This came from an adit.
The California was also partly prospected from the Pocahontas
shaft which was sunk vertically on the latter claim near the common
side-line (See Pocahontas).
Cosmopoliian Group, before its purchase by Detert, included the
Cosmopolitan, Dry Creek, South Cosmopolitan, Henry Clay, Provi-
dence, and 142 acres of agricultural land. Between 1850 and 1890
considerable work was done on these claims. Cosmopolitan shaft was
sunk 750 ft. on 67° incline with levels about 100 ft. apart from 200 ft.
to 700 ft., inclusive. On the 200-ft. level, a drift was run north 185 ft.
and on 400-ft. level, south 500 ft. On the 200-ft. level, a crosscut was
run 107 ft. in the footwall and one 45 ft. west. Below this level, the
greenstone of the hanging wall was reached only on the 400-ft. level.
The vein is reported to have had an average width of 5 ft. with a slate
footwall. The shaft was sunk in a faulted or crushed zone and struck
the slate at about the 200-ft. level. Mo.st of the work is said to have
been done in this disturbed area. There was a stamp mill on the claims
in the 1890 's, but there is no record of production, though some mill
tests were made.
Henry Clay claim has an old shaft 200 ft. deep, in which it is
reported a vein 6 ft. wide was cut, with 4 ft. of gouge.
South Cosmopolitan claim has an adit 200 ft. long.
Pocahontas claim was prospected by a vertical shaft 620 ft. deep
with levels at 74, 145. 310. 400 and 585 ft. in depth. This shaft was
near the California claim's side line and the latter claim was partly
prospected by the longer crosscuts, of which the following were run :
On 74-ft. level, west 178 ft.
On 145-ft. level, west 330 ft. to footwall vein, and east 120 ft.
6—4156
82 AMADOR COUNTY
On 310-ft. level, 561 ft. east cutting hanging-wall vein 150 ft. east
of shaft.
On 400-ft. level, 200 ft. east.
On 585-ft. level, a drift was run south on the vein 230 ft. from a
point 252 ft. west of the shaft.
In 1898, a lO-stamp mill was erected and the first bullion was
shipped in February, 1899. There was also a small production in 1900,
after which year there is no further record of activity.
So far as can be learned, most of the work done on these claims
showed broken or disturbed conditions. Details of geological conditions
underground are lacking, although current claims made during the
progress of work indicated some good assays. In the work done through
the Pocahontas shaft the country was explored from the massive diabase
hanging wall to the Mariposa slate footwall.
El Dorado {May on) claim is on a narrow lens of slate lying in the
hanging-wall greenstone immediately east of the Keystone claims, this
slate being the north extension of the east belt of slate separated from
the main slate by a large interlayered mass of greenstone, as mentioned
under the Lincoln.
This claim was prospected by a shaft 300 ft. deep, on 45° incline
with levels 100 ft. apart, and a length of 400 ft. was drifted. Vein is
reported to have an average width of 5 ft. There is no record of
production.
Fremont and Gover Mines cover 4200 feet along the strike of the
Mother Lode, including Fremont, Gover, Loyal Lode Mine and mill site.
North Gover, Bona Esperanza Quartz Mine and mill site, one-half
interest in Bona Fortuna Quartz Mine and mill site and several parcels
of non-mineral land.
History and Production
The Loyal Lode had a 20-stamp mill before 1867 and at an earlier
date the quartz on the surface had been worked in arrastres; but by
1876 a depth of only 100 ft. had been reached and the claim was idle.
Work was resumed in the 1880 's and in 1886 it was producing ore that
yielded $7 to $8 a ton in free gold. In 1888, two ore-shoots were
reported, one 200 ft. and one 80 ft. long between 'diorite' walls.
Fourteen men were working and the 10-stamp mill was crushing 15
tons a day. The 200-ft. ore-shoot had been opened its full length and
was reported 20 ft. wide. The work was done through 3 adits, the
deepest 600 ft. long and 120 ft. deep at the face. There are no later
records, and no details of the output.
The Fremont and Gover were consolidated at an early date and
the company formed in 1872 worked principally in the Gover claim.
The north or principal shaft finally reached an inclined depth of
1500 ft. (1050 ft. vertical). The only figures available indicate an
annual output of from $50,000 to $70,000 in the late 1880 's and early
1890 's, with the last reported production in 1894. In 1888, ore yielded
$9 to $13 a ton.
The Fremont shaft was started in 1900 and a new mill was built
in 1903, containing forty 1000-lb. stamps and 16 Frue vanners. Fre-
mont Consolidated Mining Company worked to a depth of 2950 ft. on
MOTHER LODE GOLD BELT S3
51° incline. They quit in December, 1918. Late in 1920, Metals
Exploration Company began unwatering the property, and prospected
it from 1921 to 1923. In the latter year, 20 stamps were put in oper-
ation, but work was stopped in August. A new company, Fremont-
Gover Mines Company, was incorporated at once by former employees,
but they were unable to finance work long, and quit in 1925. Shortly
after. Black Hills Fremont Mines Company did a little work in a shal-
low adit and a winze 100 ft. deep on North Gover claim 600 ft. north
of Gover shaft. This venture also was short-lived.
The only public record of the production of these mines previous
to 1900 is for the period 1888-1894 during which Gover Improvement
Company produced $259,389. Between 1900 and 1925, there was a
reported output of about 930,000 tons which is said to have averaged
about $4 a ton recovered ; in the later years of work by Fremont
Consolidated Mines Company the mill-heads averaged between $5 and
$6 a ton. There has never been much publicity about the earnings of
the property, but in later years at least the margin of profit was small.
Dividends are said to have amounted to $316,000. A total of $200,000
stock was issued.
Mine "Workings and Geology
The Fremont shaft was 2950 ft. long on an incline of 51°, with
levels about 200 ft. apart. Drifting was extensive and aggregated
several miles, the vein having been followed for 2500 ft. north from
this shaft. The deeper of the Gover shafts, 1500 ft. long on the incline,
is 1430 ft. north of Fremont shaft. Most of the work at this property
had been done before the owning company quit in 1918. They had
hoisting plants at both the above shafts, which were connected. The
sinking of Fremont shaft to 2950 ft. was finished in 1918. The geology
of the Gover mine and Loyal Lode was covered in Reports VIII, X,
XI and XII of the State Mineralogist. As the Fremont is described in
detail in U. S. Geological Survey P. P. 157 only a short summary is
given here.
The Loyal Lode has already been mentioned. It is a claim over
2000 ft. long on the hanging wall of the main mine, and within the
greenstone. In the Gover, two veins were developed which were sep-
arated by a reef of black slate, sometimes only a gouge but elsewhere
90 ft. or more wide, and having greenstone as its hanging wall. The
contact vein, next to the greenstone, produced the best ore, which often
occurred in pockets as stringers extending into the greenstone, and
contained arsenopyrite. The other vein was of slate-quartz ore. The
contact ore shoot was over 300 ft. long. The slate-quartz shoot (having
slate for both walls) was 280 ft. long. On the 500-, 600-, and 700-ft.
levels, the veins were 15 ft. to 60 ft. wide. The contact vein pinched
at 775 ft. and according to the Twelfth Report of the State Mineralogist
it was not until the ninth level was reached that the shaft left the slate-
greenstone contact, entering the greenstone. This point of departure
(placed at a depth of 600 ft. by Knopf) marked the beginning of the
principal 'gray ore' or schist orebodies, associated with the East
vein after it passed into the greenstone. Here the low-grade orebody
was reported to be 300 ft. long with an average width of 30 ft. The
lode was explored for 1100 ft. south and 400 ft. north of the Gover
84 AMADOR COUNTY
shaft. At a distance of about 1000 ft. south of Gover shaft on the
fourth level, the hanging-wall vein passed into the hanging-wall green-
stone. A little south of this, the vein and wall rocks were faulted west.
The 1500-ft. level of the Gover, running south, connected with the
1350-ft. Fremont north drift, both being on the 'gray ore' zone, con-
taining wide bodies of low-grade white quartz and lenses of 'gray ore,'
which is hydrothermally altered greenstone containing from 3% to 5%
of auriferous sulphide, mostly pyrite, which carried three-fourths to
live-sixths of the gold. The largest 'gray ore' body extended do-wai
to the 2300-ft. level, had a width up to 70 ft. and was in the angle
between the slate-quartz vein and hanging- wall vein. Other lenses of
'gray ore' also were mined between the 800-ft. and 2500-ft. levels,
among these being the 19 No. 2 South Shoot, 700 ft. south of shaft, and
the 19 North Shoot under the shaft. These varied in width, their wider
sections being 10 ft. to 25 ft. thick, with stope lengths up to 160 ft.
The average value of m,ill-heads concealed wide variations. The upper
levels of the Fremont shaft had developed the quartz-slate and pocket
veins.
The mill operated by the Fremont Consolidated Mining Company
handled about 200 tons daily and produced about 200 tons a month of
concentrate which was worth $65 to $100 a ton. Concentrate was saved
on Frue Vanners, and as mentioned before, carried from three-fourths
to five-sixths of the gold. This mill saved 85% of assay value. Cali-
fornia Slimes Concentrating Company worked the tailings on royalty,
recovering about one-third of remaining gold by regrinding, concen-
tration and cyanidation.
By way of contrast, it may be noted that in the early operations
on the slate-quartz ore (Mother Lode vein) in the Gover, the concen-
trate formed 2% of ore and was worth from $115 to $200 a ton.
Mining was partly done by square setting and partly with stulls,
all stopes being filled. Toward the end of the owning company's
operations, a total of 140 men were employed.
Good Hope Mine is on the west side of Jackson townsite, adjoining
the Anita. It was held by one owner 34 years, during which time little
was done. In 1896 a 10-stamp mill was built by Good Hope Mining
Company and a shaft 130 feet deep on 80° incline was sunk by 1897,
with a level at 70 feet from which drifts had been run 136 feet south
and 40 feet north. The vein in the shaft is said to show 10 inches
or more of auriferous quartz and four or five feet of slate with quartz
stringers. In the drifts, the width of ore was reported to be seven feet
or more, assaying well enough to pay, had it been in sufficient quantity.
A second level was turned at a depth of 115 feet. The claim has been
idle a long time, and there is no record of further work, if any was done.
Hardenherg Mine was worked through a shaft 500 ft. deep in early
days, but details of the results are not available. It was reopened in
1890 and equipped with 10 stamps. In 1892, $23,500 was produced
between the 300-ft. and 600-ft. levels, and in 1894, when work had
reached the 800-ft. level $12,002 more was taken out. Work stopped in
1895 at a depth of 1000 ft. The last ore milled in 1895 averaged
$4.19 a ton.
In April, 1911, the stockholders of the South Eureka Mining Com-
pany began reopening and sank a vertical shaft 1100 ft. deep and in
MOTHER LODE GOLD BELT 85
1913 and 1914 reported production of 26,478 tons which yielded $65,970
or $2.49 a ton, principal!}^ from the 850-ft. and 1000-ft. levels. In
both of the above operations the ground was found to be heavy, badly
shattered and with a wide gouge on the black slate foot wall. At 800 ft.
in the earlier workings the fissure was 15 ft. to 20 ft. wide and filled
with slate, gouge and some quartz, and in the later work the heavy
hanging wall and the gouge prevented mining clean ore.
In spite of these experiences a third reopening was begun late in
1916. About one year was spent in underground prospecting during
which time the shaft was deepened to 1500 ft. and a level turned near
the bottom. There is no record of production during that period. In
March, 1918, the property was sold for the benefit of creditors and
has been idle since. A 20-stamp mill put up for the use of the mine
was found to be on ground outside the holdings.
Italian Claim is a patent of about two acres between the Seaton
(Peerless) and Loyal Lead Claims. As originally located, it contained
302 ft. along the strike. The vein lies between slate footwall and green-
stone hanging wall. In the early 1860 's it had a 6 stamp mill, and
some 2000 tons of quartz from surface workings was crushed. About
1890 work was begun again and a crosscut was open giving a reported
depth of 150 feet. From this a small quantity of rock had been
crushed in the Seaton mill, with results now unknown. In 1932 the
present owners started work through an adit level with its portal about
50 ft. south of the north line of the claim. This enters the footwall
side of the wide vein. From it a crosscut was run 125 ft. to the
greenstone of the hanging wall. Good assays have been obtained for
a width of 10 to 15 ft. near the footwall ; also in a short drift started
45 ft. from the footwall in a southeasterly direction. Work was
being continued late in 1933 with encouraging results.
Kennedy Mine holdings embrace, besides the original Kennedy
claim located in 1856, the Bellwether, Clyde, North Clyde, North Clyde
Placer, and Silva quartz claims and other land, 156 acres in all. The
Zeila Mine, including the Coney and Bigelow, Blue Jacket claims and
several agricultural tracts, 260 acres in all now belong to the same
owners.
History and Production
Until 1871, the Kennedy was worked in only a small way, with a
whim for hoisting. In 1871 the first hoist and a 20-stamp mill were
erected. From then until November, 1873, the production was $183,427
from ore of an estimated average yield of $16.67 a ton. In 1873, two
ore-shoots were being worked. On the north end, the Kennedy ore
shoot was 150 ft. long and 2 to 12 ft. wide and had been worked to
400 ft. in depth. The Pioneer (Argonaut) ore-shoot was on the south
end-line and at that time had been opened for a stope length of 170 ft.
in the Kennedy. It was 18 ft. wide at the Pioneer line. Only four
miners were employed in stoping to produce 20 tons of ore a day, the
capacity of the mill. ]\Iining cost $4 a ton and milling $2.46 a ton.
The mine produced $300,000 to a depth of 600 ft. up to the latter part
of 1874. Soon after, the workings must have struck a lean zone as
ore is said to have given out in the south shaft, with the raking of the
86
AMADOR COUNTY
ore shoot into the Pioneer claim. No ore was milled in 1875, when the
deeper shaft was down 850 ft.
Evidently little was done thereafter until late in 1885, when the
present owners, Kennedy Mining and Milling Company, took the mine.
Unwatering began in January, 1886, and by October of that year a
new 40-stamp mill with 16 Frue vanners had been erected, and 32
stamps were in operation. In an article published locally in July, 1886,
it was stated there were large bodies of ore in the mine, "that could
not be made pay under the expensive mlethod of working 15 years ago. ' '
It was also stated that an examination of the books "shows that the
last 2000 tons of ore crushed yielded an average of over $6 a ton in
Headframe, Kennedy Mine.
Photo by Walter W. Bradley.
free gold. As the property was then fixed, running mill and mine by
steam, and using 12 or 13 cords of wood per day, and crushing with
20 stamps of 400 lb. each not more than 20 tons per day, it cost about
$16 per ton to mine and mill the rock, representing a loss of $10 on
every ton crushed."
The new mill and hoist were designed to run by water power,
and it was believed a profit could be made on the ore. The shaft was
a little over 900 ft. deep, but the 900-ft. level had not yet been turned.
That the expectations of the company were realized, was shown
by a statement published early in 1897, that in the past ten years the
Kennedy had produced $3,580,000, of which $2,000,000 was claimed
to have been paid in dividends. Approximately 36,000 tons of ore is
MOTHER LODE GOLD BELT 87
said to have been milled annually during this time (the mill having
been erected under a guarantee to crush 100 tons a day). An interest-
ing sidelight was throAvn on the grade of some of the ore mined during
this period by evidence in two suits of Argonaut Mining Company
versus Kennedy Mining and Milling Company, the first started August
11, 1894, and the second August 5, 1897, with a decision dated March
13, 1899. Testimony was given that 2604 tons of ore mined from
ground south of the Kennedy south line on the 1450-, 1550-, 1650- and
1750-ft. levels had yielded ^$62,218.45 or $23.89 a ton. A cost of
$6,119.40 or $2.35 a ton was allowed for mining and milling this.
The company has maintained a policy of secrecy and few authentic
data have been published in 30 years about the results of mining.
Storms in 1900 estimated the total cost (not including depreciation and
depletion) to be $4.50 to $5 a ton. Work had then reached a vertical
depth of 2300 ft. About that year the new vertical shaft was started
1950 ft. east of the north shaft. This eventually struck the two veins
and has been the main working entry since 1904. In that year, a new
60-stamp mill was in full operation at this (east) shaft, as well as the
old mill of 40 stamps at the north shaft. Ore was coming from levels
between 1800 and 2550 ft. deep and 250 men were employed. From
then on the mine was the deepest and largest producer on the Mother
Lode for many years until the Argonaut began to vie with it. The'
larger mill was increased to 100 stamps and for 12 years up to 1916,
from 140,000 to about 170,000 tons of ore was crushed annually. This
was taken mainly from the section between 2250 and 3450 ft. deep.
The veins ranged from 5 to 30 ft. wide, the usual width being from 5
to 12 ft. Sometimes high-grade quartz was struck, but yearly average
mill returns were reported to be $4 to $5 a ton.
With increasing depth (4050 ft. vertically in 1920 and over 5000 ft.
by 1932) and increasing cost, it has in late years been necessary to mine
more selectively, with a resultant decrease in tonnage milled, and an
increase in gold content of ore to one-third or two-fifths of an ounce
per ton. The workings have reached a depth of about a mile vertically.
Since the last report (in 1927) the mine suffered a disastrous surface
fire September 7, 1928, which destroyed all surface plant except the mill
and main office, and resulted in damage underground. The plant was
replaced and work in the mine resumed by the middle of 1929. In
1931 as a result of successful experiments, the flotation process was
installed to handle plate tailing. Since 1929 work has been done in
the lowest levels through a 65° 3-compartment inclined winze sunk from
the 4650-ft. level with the last level at 5250 ft. This last level has not
so far proved as productive as might be wished, and output has been
curtailed lately.
Figures given in a report by Waldemar Lindgren (Mineral
Deposits, 1919) for the production of the Kennedy Mine to the close
of 1915, and quoted by the present writer in a previous report appear
to be erroneous. The mine had produced over $14,500,000 up to that
time, and its total output to the close of 1933 has been approximately
$25,000,000. As the stock has been closely held, the amounts of divi-
dends and assessments have never been published. Dividends of about
$5,000,000 have been reported from reliable sources. Between 1918
and 1924 due to the expense and loss of time incident to unwatering
88 AMADOR COUNTY
the mine after the Argonaut fire, the operations are alleged to have
resulted in heavy assessments. Thereafter, some profit was possible
for several years. The company was started with a capitalization of
only $100,000 which was never increased.
Recently, a cyanide plant has been built to treat the large accumu-
lation of tailings.
Geology and Mine Workings
The Twelfth Report of the State Mineralogist (1894), gives a good
account of the geologic conditions found to an inclined depth of 2000 ft.
A cross-section at the south shaft, beginning with the footwall green-
stone and going east, shows : Vein 4 ft. wide, black slate 80 ft. ; green-
stone 200 ft. ; black slate 250 ft. ; greenstone 30 ft. ; black slate 35 ft. ;
greenstone 300 ft. and so on, slate and interlayered bands of greenstone
alternating. The slate and greenstone were contemporaneous in the
narrow bands and the gradation from one to the other so gradual as
to make a classification arbitrary. The quartz of the vein continued
in the west greenstone-slate contact to a depth of about 300 ft. near
the north shaft and 750 ft. at south shaft. Below this, in crossing the
slate, the fissure is said to have shown only crushed and foliated black
.slate, with quartz in small seams and broken fragments. It struck the
contact of the next easterly band of greenstone and began to make
quartz again at 950 ft. near the south shaft and at the 1450-ft. level
opposite the north shaft, forming from these depths another ore zone
to about 2000 ft. in depth where another strip of slate was encountered,
with poor returns in it.
The Kennedy vein continued in this manner, crossing the various
layers, as its eastward dip is at a smaller angle than that of the rock
layers through which it passes. Due to the breaking away of an
immense 'horse' or lens of country rock from the hanging wall an
east vein was formed, starting between 1700 and 2200 ft. in depth and
separated from the west or footwall vein by a maximum thickness of
about 150 ft. of the 'horse.' Both north of the deep vertical shaft on
the 3900-ft. level and south of it on the 4300-ft. level, these veins began
to merge, and in the adjoining Argonaut workings on the south there
is only one main or footwall vein through this entire depth. Another
important factor was the irregular downward course of the Pioneer
(Argonaut) north orebody which occurred near the end-line separating
the two mines. In places it was partly in each mine ; elsewhere, it raked
north or south far enough to carry it entirely into one property, as
between the 3600-ft. and 4200-ft. levels of the Argonaut, where its
north pitch carried it into the Kennedy ; below there it returned to the
Argonaut, furnishing a large tonnage of ore in the deeper levels of that
mine.
The veins swelled abruptly into lenses which furnished ore. Both
branches furnished orebodies near and at their north junction to form
the main vein but the footwall vein was more important. In later
years a length of from 1400 to 1600 ft. along the strike was explored
on some levels. In the middle levels, now closed, the ore was reported
in lenses over a length of 800 ft. ; with from 7 to 11 ft. of ore on one
vein and 6 ft. on the other, the lenses of ore lying en echelon. On the
3900-ft. level, where the two veins joined 140 ft. north of the shaft, a
MOTHER LODE GOLD BELT
89
large orebody was formed and was followed northward several hundred
feet. On the 4350-ft level south of the shaft they were separated by
33 ft. of filling, and on the 4500-ft. level they were separated by only
a few feet of slate. Here the footwall ore body lengthened to 700 ft.
and gave fine assays. The grade of ore had begun to improve in 1924
and probably more selective mining from then on had improved mill
heads. Ore from the 4350-ft. level in 1926 averaged $10 a ton and
since that time the average grade of mill heads has continued higher
than previousl5^
The average thickness of ore mined has ranged from 8 to 15 ft.
In places 30 to 40 ft. in thickness was worked and Knopf mentions a
Kraut 6-cell flotation unit in mill of Kennedy Mine, Jackson, Amador County.
Photo by Walter W. Bradley.
maximum stope width of 112 ft. The lenses of ore pinch and swell
abruptly both on the strike and dip. The superintendent distinguished
the ore from the hanging-wall vein as more slaty and with more
sulphide than that in the footwall vein which showed more free gold
and pyrophyllite (hydrous silicate of aluminum) possibly the same
mineral called by Knopf damourite (hydrous silicate of aluminum and
potassium). Generally the best ore was the banded or ribbon rock,
of hard white quartz with numerous ribbons of finely ground slate and
often ribbons of fine-grained pyrite and galena, showing building up
of the vein by repeated opening. Wliere coarse free gold occurred it
was generally associated with the light green pyrophyllite ( ? ) .
1)0 AMADOR COUNTY
Carlton D. Hulin in 1930^ published the results of a study of some
specimens of high-grade ore mined in 1925 from the 3900-ft. level. He
found the principal gangue mineral in these was fluor-apatite. The
minerals which he classified in the specimens and the order in which
he decided they had been deposited were : quartz, apatite, strengite,
pyrite, sphalerite, sericite, carbonates, galena, chalcopyrite and gold.
He concluded the apatite was here the common host for gold because
apatite has well-developed cleavages and tends to fracture easily, and
quartz was the least favorable of these minerals for gold deposition
because it lacks cleavage and is tougher than the others. Galena and
chalcopyrite were favorable, and often showed gold.
The recovery of concentrate in late years (up to the time the
flotation plant was installed) was less than 1% of ore milled. The
flotation tests (described under Metallurgy herein) emphasized that
the ores from different parts of the m;ine varied and that the apparently
low sulphide content was due at least in part to ore not being crushed
fine enough to release all gold and sulphide. The concentrate has been
high grade for a Mother Lode mine, carrying six to seven ounces of
gold a ton, which might indicate loss due partly to table adjustment in
the effort to make a very clean product.
In late years milling was done with 100 stamps and later with 60,
followed by 40 Frue vanners for rough concentrate and two Frues for
cleaning concentrate, with tailing from these last two vanners returned
to the stamps. Up to about 1915 or later a canvas plant was used to
treat tailing, with Gates concentrators and bumping tables ; a chlorina-
tion plant was also in use many years. The stamps crushed 4^ to 5
tons each daily through 24-mesh screen and though definite figures are
not available, recovery was probably 83% to 90%. Tucker gave the
lower figure in 1914
The vertical shaft, started about 1900 at a distance of 1950 ft. east
of the vein and old north shaft, has been the main working entry. It
has three compartments each 4 ft. by 5 ft. in the clear. It cut the east
vein at a depth of 3680 ft. ; and west vein at about 4000 ft. It is
4764 ft. deep, being the deepest vertical shaft in the State, and has
vindicated the judgment of the operators, giving very little trouble.
Hoisting in this shaft was done by steam, using oil for fuel from 1906
to 1926. A total of 1800 h.p. was available but normally 1200 h.p.
was used, with a maximum hoisting speed of 2200 ft. per minute with
4-ton skips. In 1927, electricity was substituted for steam, using
800 h.p. and reducing the hosting speed to 1500 ft. per minute. A new
surface plant except mill and office had to be installed after the 1928
fire, including a new steel head-frame. Three compressors at this shaft
are each operated by a 225-li.p. motor.
The recent work underground has been through a 3-compartment
inclined winze sunk on an angle of 65° from the 4650-ft. level 200 ft.
from the vein. The deepest level late in 1933 was at 5250 ft. Mining
has been done with square-set timbering, filling with waste from cross-
cuts and chambers.
About 80,000 gallons of water daily has been hoisted with 1100-
gallon water skips from the sump and from tanks on the 500-, 1000-
lEconomic Geology. Vol. XXV, No. 4, June, 1930.
MOTHER LODE GOLD BELT 91
and 1900-ft. levels. Though generally dry in the lower levels, a pocket
of water may occasionally be struck in watercourses on either wall.
Tailing has been stored for 20 years behind a concrete multiple-
arch dam 455 ft. long by 43.8 ft high as originally built, but planned
to be raised to 50 ft. To reach this about 2000 ft. of flume was built
and 4 tailing-elevator wheels were used. These are 68 ft. in diameter,
with 176 buckets each and each was run by a 15 h.p. motor. In 1933,
a new earth-fill dam was built.
Keystone Mines Corporation now owns the Keystone, Spring Hill,
Geneva, Niagara and East Keystone comt)rising the Keystone group ;
and Medean, Talisman and South Spring Hill, formerly called South
Spring Hill Mine. These claims cover over a mile in length on the
Mother Lode at and near Amador City, and contain 280 acres.
History and Production
Spring Kill Mine was the second group of quartz locations made
on the Mother Lode in the county, and was locally called the Ministers'
Mine, from its locators, who were preachers. It failed to realize the
extravagant hopes of its finders. They lost it in 1854, and the new
owners in 1855 produced 2221 tons of ore which yielded $21 a ton at
an operating cost of $10.50 a ton. Although the shaft was 350 ft. deep
and 50,000 tons of ore had been crushed in the 30-stamp mill by 1867,
it was said it had paid little, if anything, above expenses. The Talis-
man (Herlertville) claim likewise, with a 600-ft. shaft and a 30-stamp
mill before 1860, had not done so well. It remained a separate mine
until the late 1890 's and between 1890 and 1892 produced $48,316.
The Medean claim also was listed as a separate producer in 1894 and
1895, with an output of $26,600.
South Spring Hill Mine, like all those in the holdings, was located
in 1851, but apparently did not become an important producer until
the late 1880 's. In 1887 it had been opened to a depth of 800 ft. and
the 30-stamp mill was crushing 70 tons of ore daily. From 1888 to
1902, inclusive, a production of $1,092,472 was reported. There are
no figures of tonnage available, but the ore was stated in 1887 to vary
in gold content from $3 to $40 a ton and in width from 1 ft. to 50 ft.
This is one of the mines about which very little has ever been pub-
lished, and over 30 years have elapsed since the last work was done.
In 1897, previous to which year most of the production was made, it
was locally reported that about $250,000 had been paid in dividends.
The South Spring Hill shaft was sunk 1200 ft. on 60° incline with 11
levels 100 ft. apart, and over 14,000 ft. of drifts were run.
Talisman and South Spring Hill shafts are about 2300 ft. apart
and connected underground. Both have the Mariposa slates on the
w^est and greenstone on the east. The principal ore shoot is reported
to have had a stope length of 500 ft. and an average width of 5 ft.
The South Spring Hill group became important to its neighbor, the
Keystone, when it was found tlie Keystone orebodies were trending in
depth toward the South Spring Hill. This was given as one of the
reasons for closing the Keystone in 1920. Thereafter, the group was
sold to the Keystone.
92 AMADOR COUNTY
Keystone Mine grew up about the mining locations of the Granite
State and Pleasant Ridge Companies, themselves formed from several
claims located in 1851. The Granite State claims were the third group
of locations made on that section of the lode, and there were six
original locators forming the company, each claim being 60 ft. wide
by 120 ft. long. One claim showed particularly rich outcrops, and
four arrastres were built to crush selected ore which paid $100 a ton
for a few months. A one-half interest was then given in the claims
for a 12-stamp mill, but within two years the project failed, and the
claims were purchased at sheriff's sale by A. H. Rose of the Pleasant
Ridge Company and the Keystone Mine thus came into existence
in 1853.
In 1854 a total crew of 18 men produced 2204 tons of ore which
yielded $21 a ton, or a gross of $46,284. The total operating cost was
nearly $15 a ton, and monthly dividends of $200 a share were declared.
By 1867, a total of 44,000 tons had been worked, giving an average
yield of $16 a ton or $700,000 in all. The mine had been sold to Gash-
wiler and McDonald for $102,000 and like so many other of the
California gold mines remained practically a one-man or family affair
for many years, with only a partial record of results of operation pub-
lished. Some of these were :
From December 8, 1865, to December 21, 1866, production $135,-
333.30, dividends $51,300. Average recovery, $16 a ton.
For the year ended July 31, 1868, production $154,354.87 from
about 12,000 tons of ore, average yield $12.86 a ton ; dividends $75,000.
For the fiscal year of 1870, estimated $25,000 gross and $15,000
net production monthly.
For the fiscal year of 1871, estimated gross output $300,000 ; divi-
dends during calendar year of 1871, $20,000.
For 1872, from $35,000 to $40,000 gross a month during the
greater part of the year was estimated, but the record of dividends on
the San Francisco Exchange showed only one of $5,000.
For 1873, dividends of $185,000.
In 1874, 25,146 tons of ore yielded $452,507 or $18 a ton at a cost
of $7.16 a ton for mining and milling.
In 1875 it was said that since 1870 the production of the Keystone
had averaged $1,000 for each working day. As the mill then in use
contained forty 750-lb. stamps and had a capacity of 90 tons a day,
this average, if correct, would indicate a yield of over $11 a ton for the
period. The mine had then been opened to a depth of 750 ft. and for
a length of 900 ft. The details of output from 1875 to 1888 are not
at hand. However, the good grade of ore for which the mine had been
noted gave out about 900 ft. in depth when the vein entered the green-
stone. From 1888 to 1919, inclusive, the production was about $4,400,-
000. Keystone IMining Company were the last operators and ran the
property from 1911 until October, 1919. They worked ore which
yielded as little as $2.40 a ton.
Mine "Workings and Geology
The first official mention of the geology of the Keystone was by
Dr. J. B. Trask, first State Geologist of California, in 1854. He
reported the vein 3 ft. wide at a depth of 9 fathoms from the surface
MOTHER LODE GOLD BELT 93
in an adit 100 ft. long. At the end of this adit a shaft had been sunk
through the lode 7 fathoms. There was a level 94 ft. long at the
bottom of the shaft "with a power in the lode of five feet." The same
writer in 1855 stated that "The lode at the depth of twenty-one fathoms
has a power of nine feet for one hundred feet in length" and also that
"At the depth of seventeen fathoms the ores lose the character of
porosity which in the superficial ores was a striking characteristic, the
cavities containing free gold. ' ' The Keystone vein in the upper levels
had an average width of 10 ft. and the Geneva vein, 280 ft. east of the
Keystone, was from 3 to 7 ft. wide. In 1867 a depth of 375 ft. had
been reached and a length of 450 ft. on the strike had been drifted, all
in ore. Professor Ashburner, in an early report on the Keystone vein,
stated "The ground in many places is loose and the vein seems to have
been subjected to great pressure, crushing the quartz to powder." The
contact vein, with black slate footwall and altered greenstone hanging
wall was a massive vein 12 to 200 ft. wide, but generally low grade.
The pay occurred where side stringers made into the main vein from
the footwall slate. These dipped 47° east. This massive barren vein
occurs on the hanging-wall side of an important fault that has been
traced 2000 ft. and dips east 35° to 65°. The vein is composed of frag-
ments of greenstone and slate. The appearance of the mine in 1875
when it was known as the leading mine of the Mother Lode, is graph-
ically described by Raymond :
•'* * * The ore bodies in the slate which form the principal source of the
company's revenue are of variable extent, sometimes expanding- to a width of 20 ft.
and again contracting to a mere seam. It has been noticed that the expansion
generally occurs when the vein flattens, and contracts where it approaches a vertical
dip. In consequence of this marked peculiarity in the west veins, the ground is
prospected by vertical winzes which answer the purposes of horizontal crosscuts in
more regular veins. By this means the mine always presents large bodies of
reserves which would almost invariably have remained undiscovered by the usual
system of prospecting. The Keystone has been explored to a depth of 750 ft. and
a length of 900 ft. The longest crosscut is about 300 ft. On the east is found a
well-defined wall of greenstone, carrying with it a vein of low-grade quartz. There
is properly no footwall but a well marked line of fracture is found presenting the
peculiar feature known as slickensides about 300 ft. west of the greenstone. Beyond
this, exploration has failed to disclose bodies of quartz although a crosscut has been
run 120 ft. beyond the line of fracture. The yield of quartz in this miine varies from
110 to $20 a ton."
On the hanging-wall side of the low-grade vein and separated from
it by a dike of diabase, a small vein was found in a strip of black slate.
This carried arsenopyrite and pockets of gold, the largest of which was
found between the 800- and 900-ft. levels and was reported to contain
over $100,000. The banded slate ore of the west vein was finally stoped
for a maximum length of 800 ft. and an average width of 15 ft. down
to the 900-ft. level.
Below 900 ft. in depth the main fissure passed into the greenstone,
dipping flatter than the contact and traversing the greenstone to a point
estimated to be somewhat below the 2100-ft. level, where, if it main-
tains its observed dip, it is presumed it will enter the east slate. This
vein varied greatly in width however, being in one place 54 ft. wide,
and only a seam on the 1400-ft. level ; so its possibilities and its positive
identification below may be uncertain. All workings have been inac-
cessible since 1920, and notes below are from the management.
The main or Patton shaft was sunk 2680 ft. on 52° incline, being
in greenstone from 1400 ft. to the bottom. On the 1200-ft. level, 800 ft.
north of the main crosscut, an ore shoot parallel to main vein was found
94 AMADOR COUNTY
which was reported 130 ft. long by 8 ft. wide, of 'gray ore' assaying
$8 or more a ton. On 1400-ft. level, 150 ft. north of main crosscut,
the vein branched. A drift was run 650 ft. on the west branch, which
was reported to show ore 8 ft. wide at this place. A drift 270 ft. long
on the east branch was in low-grade material. The gray orebody
pitches south, being 400 ft. or more north of Patton shaft on the
1400-ft. level and 600 ft. south of it on the 2100-ft. level, where the
orebody was 100 ft. long and was mined for a width of 18 ft. This
'gray ore' is mineralized greenstone on the hanging- wall side of the
main contact vein. Ore was formed by the hydrothermal alteration
(ankeritization) of the greenstone, during which gold-bearing sulphides,
principally pyrite, were deposited forming a disseminated orebody in
which most of the gold is associated with the sulphide.
On the 2100-ft. level, 1700 ft. of crosscuts were run and on the
2650-ft. level crosscuts were driven to both contacts of the greenstone
and several hundred feet of drifts were run, but no ore was developed
on this level within the Keystone ground. A block of ore remains above
the 2100-ft. level on the gray orebody. The owners estimated in 1927
that there was 200,000 tons of proved ore that would yield $3 a ton at
the old price of gold. The vein flattened on entering the greenstone to
a dip as small as 20°, and this carried it far east of the original contact
it had occupied. The crosscut west on the 2650-ft. level was run 690 ft.
through greenstone and drifts were run 350 ft. north and 450 ft. south
without developing ore. It was supposed that this work was on the
downward extension of the so-called west vein so profitable above 900 ft.
but this was of course not absolutely certain. Only a gouge-filled
fissure was found in the slate. The crosscut was then run 500 ft.
farther west, crossing a body of slate 380 ft. wide. In the south drift,
400 ft. south of the crosscut, another crosscut was run 275 ft. in the
slate without finding ore. There was also a crosscut on the 900-ft. level
150 ft. east to Spring Hill vein, with a drift north on the vein 800 ft.
and south 300 ft. At the 1200-ft. level a crosscut was run 320 ft. to
the east vein and considerable work was done upon it, connecting with
the old workings. There is an old south shaft 1124 ft. long on an
incline of from 42° to 55° which was used for pumping.
The ore, as already noted, varied a great deal in value; the best
of it in the deeper section of the west vein workings in the slate in the
1880 's was several hundred feet west of the greenstone, was from
3 ft. to 40 ft. wide and yielded as high as $40 a ton. It carried from
11% to 1|% of sulphides, principally pyrite with some arsenical and
antimonial sulphides, which yielded $110 a ton. On the basis of ore
averaging $11 a ton this would mean about 15% of the gold in the
sulphides. In 1906 at a depth of 1000 ft. with ore that yielded $2.43
a ton there was 2% of concentrate worth $63 a ton and carrying 52%
of the gold and silver. In 1917 with ore of nearly identical yield,
sulphides formed 4.3% of ore, yielded $53 a ton and contained 95%
of the gold and silver. This last was the "gray ore" or ankeritized
greenstone.
The last mill (still on the property) contained 40 stamps which, in
the later operations, gave a reported capacity of 6 tons a day per stamp
for an entire year. There seems to be a reasonable doubt that the mil]
gave an average capacity of over 4 tons per stamp per day. This
ACCOMPANYING BULLETIN 108. BY C.A.LOGAN
MOTHER LODE GOLD BELT 95
would give an average recovery of about $3.80 per ton crushed from
1914 to 1919 inclusive. Vanners were used for concentration and no
tailing was saved, as their gold content was verv small. Recovery was
about 90%.
During the last three vears of operation most of the ore came from
the 900-, 1000-, 1200-, 1400-, and 1800-ft. levels, the last three being
most important, with little from the 2100-ft. level.
Krueger and Vaughn claims are near the Amador Queen No. 1 on
the south. These claims were worked in 1852 using arrastres, and in
1855 some ore was milled, yielding about $7 a ton. Little appears to
have been done after the work necessar}- for a patent was complete.
These claims are on the east side of the main slate belt two miles south
of Jackson.
Lincoln Consolidated Mines include the Lincoln, Belmont or Iowa,
Stewart, "Wildman, Mahoney, South Malioney and South Lincoln pat-
ented claims, 11 small unpatented claims, mineral rights under town
lots in Sutter Creek and other adjacent lands, 380 acres in all and
covering about 5900 ft. in length along the Mother Lode. The hold-
ings formerly were three separate mines, the Lincoln, Wildman and
Mahoney.
History and Production
The Lincoln was located about 1851, and the others about the same
time. All three were worked during the 1860 's. The Wildman had a
shaft 530 ft. deep and a 12-stanip mill in 1867. It lay idle from then
until 1887, when it was reopened by Wildman Gold Mining Company.
The Lincoln had two shafts by 1867, one 669 ft. deep and another
270 ft., and was said to have produced 3500 tons of ore annually from
1851^ to 1867, except for two years. There was a 20-stamp mill and
some of the ore was worth $15 a ton. The Mahoney had been opened
to a depth of 500 ft. by 1873. The vein was 45 ft. wide then. It had
been profitable to a depth of 250 ft., but below there was in low-grade
material. The early-day production from the Wildman to a depth of
500 ft., the Mahoney to a depth of 300 ft., and from the Hector portion
of the Stewart is estimated to have been about $1,500,000. The
Mahonev was 900 ft. deep when bought bv the Wildman Company in
1894.
The Wildman and Mahoney were worked by the Wildman Gold
Mining Company until 1906, then closed down until 1910, when they
were reopened and prospected until 1912, since which year they have
been idle. The Wildman shaft reached a depth of 1400 ft. on 72°
incline; Mahoney shaft, 1200 ft. deep on 62° incline, and Emerson
vertical shaft 616 ft. The Lincoln, after lying idle about 30 years,
was reopened in 1898 by Lincoln Gold Mine Development Company.
The three groups were taken over by the Lincoln Consolidated Mining
Company after 1906. The Lincoln shaft reached a depth of 2000 ft.
on an incline of 63°. The Lincoln was not productive below the 500 ft.
level, but the Wildman was stoped to about 1400 ft. and the Mahoney
to 1200 ft. deep.
1 Browne, J. Ross, Mineral Resources of U. S., West of Rocky Mountains, 18C8.
h\^
^^N^^f^,0^0^
oN
XJ\S
MOTHER LODE GOLD BELT 95
would give an average recovery of about $3.80 per ton crushed from
1914 to 1919 inclusive. Vanners were used for concentration and no
tailing was saved, as their gold content was very small. Recovery was
about 90%.
During the last three vears of operation most of the ore came from
the 900-, 1000-, 1200-, 1400-, and 1800-ft. levels, the last three being
most important, with little from the 2100-ft. level.
Krueger and Vaughn claims are near the Amador Queen No. 1 on
the south. These claims were worked in 1852 using arrastres, and in
1855 some ore was milled, yielding about $7 a ton. Little appears to
have been done after the work necessary for a patent was complete.
These claims are on the east side of the main slate belt two miles south
of Jackson.
Lincoln Consolidated 3Iines include the Lincoln, Belmont or Iowa,
Stewart, Wildman, Mahoney, South Mahoney and South Lincoln pat-
ented claims, 11 small unpatented claims, mineral rights under town
lots in Sutter Creek and other adjacent lands, 380 acres in all and
covering about 5900 ft. in length along the Mother Lode. The hold-
ings formerly were three separate mines, the Lincoln, Wildman and
]\Iahoney.
History and Production
The Lincoln was located about 1851, and the others about the same
time. All three were worked during the 1860 's. The Wildman had a
shaft 530 ft. deep and a 12-stamp mill in 1867. It lay idle from then
until 1887, when it was reopened by Wildman Gold Mining Company.
The Lincoln had two shafts by 1867, one 669 ft. deep and another
270 ft., and was said to have produced 3500 tons of ore annually from
1851^ to 1867, except for two years. There was a 20-stamp mill and
some of the ore was worth $15 a ton. The Mahoney had been opened
to a depth of 500 ft. by 1873. The vein was 45 ft. wide then. It had
been profitable to a depth of 250 ft., but below there was in low-grade
material. The early-day production from the Wildman to a depth of
500 ft., the Mahoney to a depth of 300 ft., and from the Hector portion
of the Stewart is estimated to have been about $1,500,000. The
Mahonev was 900 ft. deep when bought by the Wildman Company in
1894.
The Wildman and Mahoney were worked by the Wildman Gold
Mining Company until 1906, then closed down until 1910, when they
were reopened and prospected until 1912, since which year they have
been idle. The Wildman shaft reached a depth of 1400 ft. on 72°
incline; Mahoney shaft, 1200 ft. deep on 62° incline, and Emerson
vertical shaft 616 ft. The Lincoln, after lying idle about 30 years,
was reopened in 1898 by Lincoln Gold Mine Development Company.
The three groups were taken over by the Lincoln Consolidated Mining
Company after 1906. The Lincoln shaft reached a depth of 2000 ft.
on an incline of 63°. The Lincoln was not productive below the 500 ft.
level, but the Wildman was stoped to about 1400 ft. and the Mahoney
to 1200 ft. deep.
1 Browne, J. Ross, Mineral Resources of U. S., W^est of Rocky Mountains, 18C8.
96 AMADOR COUNTY
There were three periods of production for these mines, of which
the first was the production from the shallow zone to a depth of 500 ft.
in the Lincoln, 500 ft. in the "VVildman, and about 250 ft. in the
Mahoney. The exact figure for the total output for this period is
unknown, but has been estimated at $2,000,000 for the Lincoln (prob-
ably excessive), and $1,500,000 for the Wildman and Mahoney, prior
to 1887.
In 1898 and 1900 in the course of cleaning out the old workings
and prospecting, $22,000 was produced from the second, third and fifth
levels of the Lincoln.
The Wildman Gold Mining Company started with a 10-stamp mill,
which was enlarged to 20' stamps, then to 30. From 1887 to May 1,
1894, they produced from the AVildman Mine 94,206 tons of ore which
yielded a gross output of $417,561, after deducting freight and smelting
charges on concentrate, and bullion refining charges.
From 1894 to October 1, 1901, they produced from the Wildman
property 234,945 tons of ore of a total gross value of $834,671, or
$765,347 after deducting for freight, smelting, etc. In the same period
they produced from the Mahoney 269,681 tons which yielded a gross
output of $518,037, or $439,471 after deduction of freight and treat-
ment. Between 1895 and 1899, inclusive, the total average cost of min-
ing- and milling, including development and other improvements except
enlarging mill, was $2.59 a ton. During this time, the operations at the
Wildman yielded a net profit of $211,712. The operating loss at the
Mahoney was $144,040. Each mine was equipped with a 40-stamp mill,
containing 750-lb. and 950-lb. stamps. There is no record of any
production between 1910 and 1912.
Geology and Mine Workings
The Mariposa slate between the Old Eureka Mine and Amador
City is interbedded with several narrow bodies of greenstone and the
mines of the company are grouped around the slate-greenstone con-
tacts. The andesite has been in part altered to amphibolite schist.
Going north from the Wildman the vein increased to 45 ft. in width
on the surface, and is said to have supplied much rich ore in the
early days. It branched, or was split by a greenstone horse, at the
north end of the Mahoney, one branch turning eastward into the Hector
portion of the Stewart, with greenstone on the footwall, the other
branch passing into the Lincoln with schist, and farther off, greenstone
on the hanging wall. There was usually a heavy gouge, with ore at
times on both sides of it. The ore in the Wildman and Mahoney was
in the contact vein, along the schist-slate contact, in the upper levels.
At depths reached in the earlier operations, namely about 500 ft. deep
in the Wildman and 250 ft. in the Mahone}^ the mineralization began
to pass from the contact into the schist, where large bodies of low-
grade altered schist, impregnated with pyrite, were found. The gray
schist ore was on the footwall of the solid quartz vein. The wide
section of rock on which mineralizing solution acted resulted in dis-
persal of the gold to such an extent that it was necessarily lower grade
than if it had been confined to a narrow fissure. The schist dike was
from 60 to 295 ft. thick. Mining in the contact vein continued to the
1300-f t. level, in the period between 1895 and 1899, the ore coming from
MOTHER LODE GOLD BELT 97
that vein between the 500- and 1300-ft. levels and being of low average
grade. In 1899 the development of small ore-shoots found by diamond
drilling in the schist dike began. As they had no dump room for waste
on the surface, they milled everything that would pay for crushing,
and the average grade was far below that needed to make ore, even at
the low cost of operation.
After the Lincoln shaft was sunk to 2000 ft. a drift was run south
over 2200 ft. passing through the Mahoney claim and to a point under
the Wildman 1400-ft. shaft. Long crosscuts were run into the footwall
from the 500-, 1200- and 1950-ft. levels of the Lincoln shaft, and on the
1200-ft. level one Avas run into the hanging wall, all apparently without
finding ore.
In the Wildman Mine, the north drift on the 1400-ft. level was
run 437 ft. and the south drift 666 ft. For a length of 250 ft. on the
north, the vein averages 5 ft. wide, but the assay value is not known.
In the south drift, according to information furnished from owners'
records, ore began to make 193 ft. south of the shaft and increased to
25 ft. in width within 185 ft. A horse of ground had slipped into the
fissure here, causing a pinch in the vein for about 75 ft. Beyond this,
the vein began to widen again, increasing from 10 ft. just south of the
horse to 100 ft. wide at the face. This latter width was sampled in
sections of 5 ft. each, and the resulting average of the 20 samples was
reported to be $3.62 a ton. The general pitch of the Lincoln-Mahoney-
Wildman orebodies appears to be southward, as is true also in the
mines nearby on the south.
Little Illinois Mine is on the J. H. Thomas Ranch containing 537
acres, lying to the south of the Pocahontas mine. Some work is
reported to have been done here in the 1860 's, but no record remains
of it. It was reopened between 1908 and 1914, and a few tons of very
good ore was reported crushed. The shaft was 147 ft. deep late in
1914 when last visited, and only 150 ft. of drifting had been done,
100 ft. of it in a shallow tunnel. It was closed down soon after, and
has been idle since.
The workings are reported to have shown a vein with an average
width of 5 ft., between slate footwall and greenstone hanging wall.
Nothing is known regarding the prospects, as the last operator, Little
Illinois Mining Company, left no records.
Mammoth Mine is on the 'black metal belt' in Spanish Gulch,
adjoining the Valparaiso on the south. Its earliest history is unknown,
but in the early 1880 's it produced some rich ore. Between 1885 and
1888, a tunnel 8 bj^ 8 ft. in cross section was run 3500 ft. northerly.
For 3300 ft. no ore worth speaking of was found, except some small
seams. AVhen a point was reached about under the earlier strike,
and 800 ft. below the surface, quartz increasing from small stringers
to nearly the width of the tunnel was entered, and this carried some
of the typical rich ore of the belt, containing arsenopyrite and gold.
In 1886 there was a 10-stamp mill on the mine, but the rich ore was
mortared by hand.
Little appears to have been done at this property in late years, the
only recent record of production being of a few thousand dollars in
7—4156
98 AMADOR COUNTY
1924. Knopfs states the ore occurs "in horizontal veinlets of quartz
that are restricted to the vicinity of the contact of black slate and green-
stone. The veinlets follow horizontal joint surfaces, and most of them
are but a few inches thick."
Moore Mine. This old mine (on agricultural land a mile and a
half south of Jackson) had been idle over 30 years when Moore Mining
Company began reopening it under option to purchase in August, 1921.
There is no record of the results of the operations in the 1880 's, during
which the mine had been opened to 640 feet, on an incline of 52°.
When the shaft was reopened it was found that the fifth level
(435 ft. inclined depth) which had been drifted 400 ft. in the heavy,
crushed black slate in the main fault, was caved full. It was reopened,
but did not carry pay. The black slate there is about 60 ft. wide. In
a fissure branching from the main fissure, and striking nearly due east
into the greenstone on the hanging-wall side a vein of quartz ribbon
rock was found which carried from 4 to 12 ft. of ore. This gave such
flattering prospects that a new 20-stamp mill and other buildings were
erected in 1922 and the first ore was crushed in October of that year.
Work continued thereafter until June, 1929. It was found that
the former operator had stoped down to the 340-ft. level. The shaft
was deepened to 2291 ft. and a great deal of prospecting work was done,
but resulted in one disappointment after another. Only small lenses
or faulted segments of ore were found in the main fault fissure (Moore
vein system) which had been relied upon to furnish tonnage of the
character mined by Nevills in the old operations. Several other veins
were prospected from the Moore shaft without revealing ore.
The total production reported from the Moore from 1922 to 1929.
inclusive, was 92,935 tons yielding $564,624.
Geology and Mine Workings
The ground embraced in the Moore options covered on the west
a narrow band of Mariposa slate traversing greenstone in a northwest-
erly direction, and on the east a complex of Mariposa and Calaveras
slates, wider than the first belt of slates mentioned and parallel to it.
The shaft is sunk on the easterly strip. The deeper work showed the
Moore vein system, in and near the contact, badly broken by the
contact fault. Ore was cut off about 750 ft. deep, and below there little
ore was developed. Levels were opened at 640, 950, 1100, 1200, 1800,
1950 and 2100 ft. Small amounts of ore were found along the fault on
the 1100-ft. north drift near the shaft and 500 ft. north of it. On the
1800-ft. level the Moore vein was found 170 ft. northeast of the station,
and a length of 150 ft. gave some good assays, though it was not all of
payable grade. This section was cut off on both ends by faults. When
opened at 1500 ft. depth this shoot was found to be short. On the
1950-ft. level it was 50 ft. long by 8 ft. wide with an average value of
$7 a ton, but was not found on the 2100-ft. level. The northwest drift
on 1800-ft. level was run over 1200 ft. in search of further orebodies
on the Moore vein, without success. The theories of several geologists
as to the direction and amounts of movement of the supposed faulted
orebodies on the dip and strike along the main fault were tried out
1 Knopf, Adolph, The Mother Ix>de System of California: U. S. G. S., Prof.
Pap. 157, p. 70, 1929.
MOTHER LODE GOLD BELT 99
unsuccessfully. Several other veins which cross the property were
given names to identify them with veins in other properties, of which
they were presumed by the Moore operators to be extensions. These
included the 'South Jackson,' 'Aetna,' 'Zeila' and 'Kennedy-
Argonaut,' and prospecting crosscuts and drifts were run to and
along all of them. On the 640-ft. level a drift was run on the 'Aetna'
vein. On the 1800-ft. level a long crosscut was run westerly to the
'South Jackson' vein from the north drift. On the same level a
crosscut was run 1800 ft. to the 'Kennedy- Argonaut' fissure, the
latter occupying at the surface the narrow band of Mariposa slate first
mentioned hereunder. None of these disclosed ore.
The net result of the venture was a substantial loss to stockholders.
New London {Lucille) Mine, adjoining the Plymouth on the south,
had been worked to a depth of 1130 ft. in 1888, and no record is avail-
able to show the production, probably because of the o^vners' refusal to
give information. It was at that time part of a group covering 12,000
ft. on the Mother Lode. By 1890, the main shaft was 1340 ft. long on
%o° incline and another shaft was 300 ft. long. The lower levels were
run as follows :
1300-ft. level, 550 ft. south, 150 ft. north.
1200-ft. level, 630 ft. south.
1000-ft. level, 600 ft. south.
The 200-ft. and 300-ft. levels were also opened to work the upper
ore-shoot. This shoot was reported 200 ft. long by 7 ft. wide. The
lower shoot apexed at an inclined depth of 930 ft. and lay 400 ft. south
of the shaft on 1000-ft. level but from what can be learned must have
been short, as it seems to have been stoped for a length of only 50 ft.
on that level.
After 1890, the property was idle until 1894 when the Lucille
Mining Company reopened it and put up a 40-stamp mill, but shut
down in a short time.
North Star, Mclntire, Boyson, Occident, Granite State and part of
Beatrice claim were iinder option in 1926 and 1927 to California
Mclntire Mining Company for which Fletcher Hamilton was agent.
A shaft about 1000 ft. deep on the North Star claim was unwatered
to the 600-ft. level and considerable new work was done. The claims
are on the Mother Lode north of Sutter Creek. The greenstone lies on
the footwall, followed on the east by Mariposa slate containing the usual
greenstone dikes or sills. Most of the work was done on the North
Star and IMcIntire claims. The old work on the North Star, besides
the shaft, included a crosscut southwest on the 600-ft. level and a drift
2500 ft. northwest into adjoining claims on a gouge and scattered quartz
seams in the slate in search of a possible continuation of the South
Spring Hill orebody, which is said to have occupied the same fissure.
No ore was found.
The new work included a crosscut 100 ft. northeast to a contact
of greenstone and slate with drifts 400 ft. each way on the contact,
which was found to be frozen and barren ; the southwest crosscut was
also extended 500 ft. farther, making it 800 ft. long. Here the footwall
contact of greenstone and slate was prospected. Two gouge-filled fis-
sures, 50 ft. apart, were encountered. Going in a northerly direction
100
AMADOR COUNTY
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MOTHER LODE GOLD BELT 101
from this crosscut for a distance of 550 ft., the face reached a point
180 ft. from where the bottom of the 200-ft. Mclntire shaft would have
been, had this shaft been deepened. Southwest, these gouge-filled fis-
sures were cut at several points, 400 ft. of new work having been done
in that direction. The gouge and black slate showed only small scat-
tered bunches and seams of quartz, and Roger Beals, who was superin-
tendent, stated that assays showed nowhere over a few cents in gold,
although it had been claimed that there was a prospect in the Mclntire
workings, on the 200-ft. level. This work off the southwest crosscut
prospected the Mclntire ground for 950 ft. The work on the hanging
wall contact first mentioned prospected that contact on the east side of
the North Star claim for 800 ft. Three crosscuts into the greenstone,
each about 60 ft. long, developed nothing. The greenstone there is
about 300 ft^ tliick. The old drift, 2500 ft. long, prospected the Boyson
and South Keystone claims and a crosscut from it is said to have pros-
pected part of the South Spring Hill claim.
Two conditions are noticeable in the workings on the 600-ft. level —
first, the dryness of the ground, and second, the absence of any cross
veins. The slate is plicated in small broken folds in places, and ground
to gouge along the fissures with considerable quartz intermixed ; but
the very low reported assays indicate that the absence of ore is not due
to faulting. The gouge has so completely dammed the fissures that
although considerable water enters the shaft from the surface, and a
small stream also runs along the lode, the workings are dry away from
the shaft.
The company quit work about the middle of March, 1927.
Old Eureka (Amador Consolidated or Eureka) Mine was opened
in 1852 and the first mill, of 10 stamps, was erected the same year.
The mention made of this mine by Dr. J. B. Trask in his report for
1855 is interesting. This refers to the Eureka claim.
"The whim shaft A has been carried from 7 to 16 fathoms during the past
year. The adit enters from the west and is about 100 feet in length. The upper
gallery has been carried south of the adit 114 feet, and north 75 feet. The level
at the bottom of the 16 fathom shaft is 144 feet in length. The rocks are a graphic
slate, very firm and often charged with pyritic crystals.
"The rich thread, which commenced at the surface, and for fifty feet in depth,
was highly pyritiferous ; is found at the bottom of the main shaft much more pro-
ductive. The pyrites have ceased entirely at this depth, and the hilo is composed
of metallic gold, not disseminated, but forming a true vein, at times exceeding
three-eighths of an inch in thickness. The vein has been struck in an adjoining
mine about 1000 feet to the south. This is the only instance of a true vein of
metallic gold having been found in this state."
The adjoining claim on the south was the Badger on which 10
stamps were built in 1854. A new 20-stamp mill was put on the
Eureka in 1856 and 20 stamps more in 1857. Alvinza Hayward finally
obtained control of both mines in 1859 and consolidated them. In 1867
the north shaft was 1230 ft. deep, middle shaft 960 ft. and the southern
one 760 ft. deep. There were 56 stamps dropping in the two mills,
crushing 80 tons a day, and ore was also sent to custom mills. Hay-
ward, always secretive, refused to give details of production, but local
report placed the output at $6,000,000 up to 1867. In 1866 it was said
30,000 tons had yielded $27 a ton at a working cost of $5 a ton. In
March, 1868, the mine was sold for $750,000 to the Amador Mining
Company. For 13 months ended October, 1868, the total yield Avas
$566,945.92 or $21.88 a ton. For the year ended July 1, 1869 (over-
lapping the last period) 30,361 tons yielded $617,542 or $20.34 a ton.
102
AMADOR COUNTY
3
H
O
MOTHER LODE GOLD BELT 103
In 1870 the yield was $341,701 and in 1871, on account of a labor
strike, only $201,357. For 14 months, December, 1872, to January,
1874, a total of 22,465 tons yielded $402,294 or $17.91 a ton. For 14
months ended April 1, 1875, the yield was $239,717 in bullion and
$20,254 from concentrate, from 22,098 tons, indicating a marked drop
in gold content of ore. In 1874 the 'boulder ledge' on the west of the
'true ledge' was being mined 30 ft. wide and was yielding $10 a ton
on the 800 level. In 1875 it was evident from the superintendent's
report that the upper shoot on the 'true ledge' was being bottomed
at 1700 to 1750 ft. in depth. The shaft was continued as a prospect
shaft to 1965 ft. At that time a large reserve of low-grade ore was
claimed. Work finally stopped in 1881. A total of $12,000,000 to
$13,000,000 seems a fair figure for the production during the 30 years
of operation.
In 1916, a well-financed company bought the property and began
unwatering it. The shaft was found in very bad shape on account of
having been sunk in the Mariposa slate. It was deepened to 3500 ft.
and levels were turned at 1700, 2125, 2950 and 3500 ft. and 1200-ft.
level was reopened. On each of these except the lowest, from 1450-ft.
to 1640 ft. of drifts M^ere run. A crosscut was run west 800 ft. on
3500-ft. level. All of this exploration failed to reveal ore that would
pav under conditions then existing, and the work was stopped late
in'l920.
In 1924 Central Eureka Mining Company purchased the Old
Eureka holdings and have done considerable work in it since, although
this was mainly incidental to the working of its principal orebody on
the south line of the Old Eureka until 1930, when the lower levels of
Central Eureka were abandoned. Since then, Old Eureka has been
more actively explored.
Geology
The main vein was found to have had a slate footwall with heavy
gouge and greenstone (altered andesite) hanging wall in those workings
that had furnished ore. The andesite extends for 800 ft. on the strike,
and the ore was stoped for 450 to 500 ft. on the strike and evidently
gave out, both on dip and strike, with the thinning out of the andesite,
about the 1700-ft. level. The shaft and most of the other workings
between 1700 and 3500 ft. in depth were in Mariposa slate, which is
soft and swelling ground. The andesite lens thinned out to such an
extent that it was no longer a factor in controlling fissuring, and the
vein so far as explored was for the most part a mass of barren or low-
grade stringers in the slate between these levels. Wide veins of
]ow-grade quartz were coming in at the south faces of the 2950-ft. and
3500-ft. levels. The former level was run to the Central Eureka end-
line. A number of crosscuts were run without striking ore, although
many think that the possibilities in this exploration of the walls of the
main vein had been far from exhausted when work was stopped. The
longest crosscut was 800 ft. west on the 3500-ft. level. No ore of milling
grade was found except a few small pockets.
The following are the positions of other veins with relation to the
main Old Eureka vein.
104 AMADOR COUNTY
Central Eureka lowest ore-shoot is reported about 300 ft. west of
Old Eureka vein at the common end-line at 3500 ft. in depth. Due to
the direction of this end-line the length of the original Central Eureka
claim along the strike shortened rapidly in depth. This vein was
reported low grade where crosscut in the Old Eureka. As the later
developments in the Central Eureka on this ore-shoot have been prin-
cipally below the 3500-ft. level and have extended to date to 4850 ft.
in depth, and several hundred feet north of their shaft, this is an
example of the uncertainties of mining. The purchase of the Old
Eureka prevented possible expensive litigation.
The Kailroad vein is about 500 ft. east of the main Old Eureka
vein. It produced $70,000 to a depth of 340 ft., the reported grade of
ore being good.
The Wolverine vein is probably a little in the footwall of the Old
Eureka.
The Wildman-Mahoney vein and the Lincoln vein are several
hundred feet west.
Original Amador Mine is said to comprise the first group of loca-
tions made in Amador County on the Mother Lode. It was opened in
1852. At present it contains the Original Amador, East Amador,
Amador Wedge, Great Eastern, Eclipse Extension and Last Chance
claims, covering 4400 ft. on the Mother Lode. The geology and mine
workings were described by James D. Hague in 1872, and his report is
outlined in the next two paragraphs.
The underground workings extended 650 ft. northwest from the
south boundary. There were three shafts, of which the south shaft was
175 ft. deep, the middle one, 196 ft. northwest from the first, was
356 ft. deep, and the third shaft was just started. The vein, having
hanging and footwall seams, varied from one to 20 ft. wide, had a
hard, slaty-greenstone hanging wall and black-slate footwall. The
hanging-wall vein was usually the larger, was of hard, white quartz,
frequently mixed with greenstone and sometimes joined to the green-
stone of the hanging wall with no gouge nor well-defined limit between.
The footwall vein was narrower, and in the black slate. It showed an
abundance of clefts or crevices in which were seams of sulphurets and
visible free gold. This vein was always the richer of the two, and was
stoped in the old workings (above 356 ft. in depth), while the hanging
wall vein was left. The veins at times were together, at times separated.
Below the third level the vein pitched east into the greenstone, with
50 ft. of greenstone between the vein and the footwall slate.
A 40-stamp mill was completed in 1872, an English company
having purchased the property. About 3600 tons of ore crushed
yielded from $4 to $6.50 a ton, and the tailing loss was $2.50 to $3.26
a ton. This company spent considerably more than they took from
the mine during the next two years, but no complete record of their
work remains.
The later work by Original Amador Consolidated Mines Company
began in 1908. The property was one of the smaller producers of the
lode until 1918, since which year it has lain idle. The production
between 1910 and 1918 was between $90,000 and $130,000 a year. The
operations were profitable in spite of the general low gold-content of
ore, and permitted the purchase of the claims adjoining the Original
MOTHER LODE GOLD BELT 105
Amador. From 1909 to 1915 a mill of twenty 1000-lb. stamps and
8 Deister concentrators was operated. This had a capacity of 90 tons
a day. The ore crushed during this period came largely from, develop-
ment work and averaged $3.44 a ton with a reported average operating
cost of $2.56 a ton.
In 1915 the capacity of the mill was trebled, with the installation
of two 8-ft. by 3-ft. Hardinge mills, classifiers, etc. There was some
falling off in average grade of ore thereafter. A large tonnage of low-
grade ore was claimed to have been blocked out. About this time some
landowners began to complain of alleged damages to their land from
tailing and in some cases to demand payment therefor ; and in 1917 the
California Debris Commission addressed protests to several mine own-
ers about tailing entering streams. Both the Keystone and Original
Amador companies were put under bond in June, 1917, in this connec-
tion. The latter closed in 1918 after having made a greater production
in 1917 than in any previous year. The last full year's output was
low grade.
Mine Workings and Geology
The mine is opened by an inclined shaft 1238 ft. long with 9719 ft.
of drifts, 7023 ft. of crosscuts and 27,465 ft. of raises. The geology of
the upper section has already been mentioned. The main vein left the
contact of Mariposa slate and greenstone and entered the greenstone
about the 300-ft. level and assumed a much flatter dip below there.
The shaft, which had followed the vein to 300 ft., was in the footwall of
it below there, and also in the greenstone. The ore on the hanging
wall vein below the 300-ft. level was partly from the vein itself and
partly altered greenstone lying on the hanging-wall side of the quartz.
The vein proper is said to be 15 ft. thick or more, and because of its
flat dip showed a width on the level up to 90 ft. according to Knopf.
East of this vein, parallel veins of 'gray ore' consisting of quartz
stringers and altered greenstone, have yielded ore. According to
Tucker, these are from 12 to 20 ft. wide. As the mine was not visited
by a representative of this division between 1914, when the shaft was
780 ft. deep, and the time of closing in 1918, the details of geology
below there are not at hand.
The footwall vein which was chiefly worked in the earlier oper-
ations on the upper levels is reported narrower and better grade than
the main vein, which it joins north of the shaft. It is a stringer lead
in slate, 6 to 8 ft. wide.
In the main vein shrinkage stoping (top slice and fill) was used
because of the firm walls and width of ore, and this, with the moderate
depth, permitted low-cost operation.
The mill made a recovery of 90%. Concentrates formed from
li% to 2^% of ore. They ranged from $40 to $75 a ton in value and
contained usually from one-third to one-half of the gold.
Little stoping was done below the 700-ft. level, the ore milled
from below there having come from drifts and raises run in the course
of development work. The 700-, 800- and 1200-ft. levels were each
run several hundred feet north and south of the shaft, it being claimed
that low-grade ore is exposed for a length of 1000 ft. on the 700-ft.
106 AMADOR COUNTY
level. This leA^el corresponds nearly in elevation with the 800-ft. level
of the Keystone.
The work of unwatering the Original Amador was started in
August, 1934. It is reported that the same company may also take
over the Bunker Hill Mine, adjoining on the north.
Pioneer Mine adjoins the New London on the south about one-half
mile south of Plymouth, and like the latter lies about midway in a
mile-wide area of Mariposa slate. The period of principal activity
appears to have been in the middle 1890 's, when the largest recorded
annual production was $15,000. The shaft was 550 ft. long on an
incline of 60° and five levels were turned, 100 ft. apart.
It contains two veins, the east vein of massive quartz and a west
vein of banded quartz which is said to have contained the best ore. The
shaft was sunk on the latter. "While some good ore was produced in
the upper levels, it is said that in the bottom the quartz was low grade.
Plymouth Mine
The holdings include the Southerland, Oaks and Pacific, Simpson
and Aden, Reese, Phoenix East, Plymouth, Phoenix Mill site, Reese and
Woolford, fractions of the Indiana, Rising Star, Conville and lode
claim 5181, the Beta claim and 22.77 acres of other land, a total of 126.3
acres, all in Sec. 11, T. 7 N., R. 10 E. Most of the ore was produced
under the Simpson and Aden and Oaks claims.
History
The claims forming the present Plymouth Mine were originally
taken up in 1852. The Southerland, Simpson and Aden claims
were known as the Phoenix Mine, which was opened in 1859. Up to
1875, this had been worked steadily and in the latter year had two
shafts, 200 ft. apart and each 900 ft. deep. Ore occurred in a ''large
body of low-grade quartz" and was worked at a cost of $5.50 a ton.
Soon afterward the Phoenix holdings were sold to the Empire Com-
pany, and by 1879 the shafts now called the Empire north and south
shafts, were'l200 and 1280 ft. long, respectively, or 1020 and 1100 ft.
deep vertically, where sinking stopped. Ore averaging $9 a ton was
then being mined between the 1000-ft. and 1100-ft. levels, on the main
Empire ore-shoot. The North Empire ore-shoot was found in 1881
in a drift run north on the 900-ft. level, and was stoped from the
900-ft. to 1200-ft. level.
The Pacific vertical shaft (which became the main working entry
in later years) was started in May, 1880, and was 1000 ft. deep by
October, 1880. The southward rake of the main Empire ore-shoot
carried it under the Oaks claim of the Pacific Mine, where it was mined
by the Empire Company. The resulting lawsuit was won by the
Pacific Company, and this led to the consolidation on June 1, 1883,
under the name of Plymouth Consolidated Mining Company. The
Woolford shaft was sunk 400 ft. deep in 1885.
The production of these mines prior to consolidation was reported
about $2,500,000. Soon after they were grouped, the property became
the principal producer of the county. As many as 147 stamps were
operated by water power. From June 1, 1883, to January 1, 1888,
MOTHER LODE GOLD BELT 107
the company produced $3,804,499 from which 55 dividends totaling
$2,200,000 were paid. On January 24, ,1888, a fire was reported on
the 1200-ft. level and was not finally reported as being extinguished
until the mine was flooded. This fire is alleged by some to have
occurred just when good ore appeared to be giving out. The Pacific
workings were reopened in 1889, and in the four years following pro-
duced $215,518. From the above figures it would appear that the total
l)roduction by the old companies up to the complete r>essation of work
in 1892, was "^$6,520,017. In a report by Albert Burch in 1911. it was
stated, however, that the old companies up to 1891 produced $7,123,-
009.56 from 877,000 tons with a net profit of nearly $3,000,000 and
that bullion produced amounted to $6,659,079.11, the balance pre-
sumably having come from concentrate and tailing. Between 1898
and 1902, about $44,000 was produced from the old tailing dumps.
The mine lay idle from 1892 to 1911, when the Pacific shaft was
reopened and a winze was sunk from below the 1600-ft. level to 2000 ft.,
developing ore enough to result in the formation of Plymouth Con-
solidated Mines Company, Limited, in London, with a capital of 240,000
shares of one pound sterling ; 204,482 pounds sterling was paid for the
property. From August 1, 1914, to the end of 1924, a total of 1,037,373
tons of ore was milled and yielded $5,718,889. Dividends paid from
these later operations amounted to $758,000. After 1920, however, the
cost of operation increased until it equaled or at times exceeded yield.
In February, 1925, the mine was forced into receivership to protect a
local loan, and was sold to Argonaut Mining Company. The workings
had by that time reached an inclined depth of 4300 ft. (the shaft below
1600 ft. having been turned to an incline of 60°.) The principal known
orebodies had been worked out to this depth.
Argonaut iMining Company sank the shaft from the 4300-ft. level
to the 4450-ft. level and milled some ore which added $515,292 to the
production, from 1925 to 1928, inclusive. They decided, however, not
to appropriate the sum needed to put the mine in proper shape and
sink another 150 ft. The only work done since 1928 has been some
prospecting on the upper levels, which stopped in 1931. Taking the
larger of the figures quoted for production prior to 1889, the Plymouth
holdings have produced $13,357,190 from 2,029,710 tons of ore. From
this, if we estimate dividends of $750,000 for the operations prior to
June 1, 1883 (when ore of much better grade was handled than later)
the total dividends were about $3,700,000 or nearly 28% of total pro-
duction.
Geology
The Mariposa slates at Plj^mouth are a mile in widtli and it is
entirely within these slates that the paj'able ore has been found. On
the east, the Mariposa formation is separated from an outlier of one
of the granodiorite domes of the Sierra Nevada batholith by a strip
of amphibolite schist only one-fourth mile wide. This schist has been
referred to tlie Calaveras formation (Carboniferous), and it is believed
to have been originally andesite. The andesite cut in some of the mine
workings is believed to have had an important influence on the position
of ore. Some sandstone, formed of chert fragments, and some con-
glomerate are found in the Mariposa formation, but it is typically a
108
AMADOR COUNTY
3,655' LEVEL
„r.' tf-r(5)t30a Ml»'lQ)i36/iO. ^)»-!>)t (G) 45 60
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■«'(6>$700
,g 0'-3'(S)40C. 3'-4' (61436
- 0-3(Q)tl2 88 A'g)tl2u
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6'(® fi 14 60
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' 7<^'lS>in20 ,
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0-1(0184300. i'3ia'i4e4a y-shiatofa. hn-ArJileoo
7' is 82765
M 0'-r(g8400. l-6'la)t900. 6'-7t2'[ia8l?80
' 7te'ia»925
.^i 0-3fe'(Ql 8?2 60. 3^2'- 7fe" (018500
'- 7J'2'®»1335
-3^50' LEVEL
Distribution of gold and structural features of typical quartz vein inclosed in
slate, Plymouth Mine. Reproduced from U. S. G. S., Prof. Paper 157,
p. 28. Geology by Robt. J. Duncan.
MOTHER LODE GOLD BELT 109
black, carbonaceous clay slate with small iutrusious of basic igneous
rocks and beds of clastic volcanic material which originally were
spread out as mud flows of andesite or similar volcanic ash on the
ocean floor at the time the Mariposa beds were being deposited. The
present dip of the schistosity of the slate is nearly vertical, but unlike
the usual dip in most sections it is to the west. Though tilted and
telescoped, and rendered slaty by pressure, the Mariposa beds are other-
wise little changed.
The Calaveras formation (Carboniferous) on which the Mariposa
beds rest, is another complex of altered rocks, which were in part
originally sedimentary and in part igneous. All the members of this
formation have been intensely altered and the igneous members have
been so completely changed both in physical structure and chemical con-
tent that they are now greenstone schists, locall}^ called amphibolite
schist. Malcolm Maclaren regards the contact between the Mariposa
slate and the amphibolite schist on the east as a fault contact, dipping
east at an angle of probably about 60°.
The Veins and Ore-Shoots
Three systems of lodes have been found, comprising main veins and
spurs, and called the Empire, Reese and "Woolford and hanging-wall
contact veins. The most important, the Empire, is believed to occupy
a fissure opened by a reverse fault, on the footwall side of the mine.
In the deeper levels it is the tj'pical slate-quartz stringer leads or
'ribbon rock' of the lode. This is the vein opened in the Phoenix
workings and followed to a depth of 1200 ft. in their old shafts prior
to consolidation. It does not outcrop prominently except on the New
London claim. Its strike is generally north and dip 62° east, cutting
across the schistosity of the slate at a small angle in dip and strike.
The Phoenix or Empire ore-shoot was in this vein, having its apex in
the Simpson and Aden claims. It raked at a flat angle, 40° to 50°,
to the south, and this carried it into the Oaks claim which was being
worked by the Amador Pacific Company through the Pacific shaft.
From the surface to about 400 ft. it was of only average grade, and
from there to 1000 ft. even lower, so that between 600 ft. and 900 ft.
much of it was left unstoped. From 1000 ft. to 1500 ft. it was richer,
and in 1886 out of a gross production for nine months of $447,547.13
there was a profit of $254,402.13 above operating expenses, and divi-
dends of $225,000 were paid. The ore-shoot was claimed at that time
to be 800 ft. long. The 1500-ft. level was just being opened and no
ore had been stoped there ; but it is not certain if the 800 ft. in length
referred to the Empire shoot alone, or to the combined length of it and
the Pacific ore-shoot. The vein was reported averaging 30 ft. wide and
containing 1^% of concentrate worth $135 a ton. The average value
of this ore was $6 to $8 a ton. In the upper levels this ore-shoot was
450 ft. in horizontal length. It is said to have lain on the footwall
down to the 1000 ft. level, and below that on the hanging wall.
Pacific vein is considered as a spur of the Empire leaving it a little
north of the Empire north shaft and striking a little east of south to
near the Indiana shaft, where the Indiana vein has the appearance of
a hanging-wall spur. Maclaren connects this vein with the New
London. Three ore-shoots were worked in tlie Pacific between the
no Amador county
1600-ft. level and 835-ft. level, above which they are said to have died
out. All three were on the south side of the Pacific shaft. Their
occurrence is attributed to the junction of the two veins. They rake
toward the Empire shoot, and the vein in which they lie dips 80° E.,
so that the Pacific and Empire shoots merged about the 2000-ft. level.
Below there the rake of the ore becomes perpendicular. No details are
at hand regarding the Pacific operations, but some interesting items
were observed when the shaft was unwatered in 1912.
Main Ore-Shoot in Depth
From the 1140-ft. leve}, ore had been stoped for nearly 200 ft. in
length and the back gave an assay of $19.34 over a width of 41 inches.
On the 1600-ft. level, a vein 16 ft. wide was exposed in the old work-
ing, but it was too low-grade to make ore. This drift was extended
south. Finally, ore 5 ft. wide was developed for a length of 255 ft.
and with an average value of $6.96 a ton on this level. On the 1850-ft.
level, the ore-shoot proved to be 334 ft. long, with an average width of
4^ ft. and average value of $6.32 a ton. There was a heavy post-
mineral gouge on the hanging-wall side on this level. Below there, the
orebodies decreased in size but held up in value to about the 2450-ft.
level. From there to the 3050-ft. level, the main vein was poor or
unpayable, and was also disappointing between the 3235- and 3650-ft.
levels. From the 3400-ft. level about 380 ft. north of the shaft, a
winze was sunk and in 1922 struck ore which developed a stope length
of about 100 ft. to 180 ft. and a thickness up to 9 ft. Some 20,000 tons
of ore mined from this ore-shoot averaged $10 a ton. In the workings
above 3835- and 2925-ft. levels this ore was crushed 'ribbon rock'
with gouges on both walls varying from a seam to 1| ft. in thickness.
In the 3925-ft. level it showed 9 ft. of ribbon quartz, broken and sugary
in texture from faulting, and containing visible gold in places. In
spite of the good grade of this ore, the expense of working through the
winze was too high to permit a profit. The shaft was eventually sunk,
after this ore had been mined.
The Reese and Woolford vein has not contributed payable ore.
A shaft was sunk on it to a depth of 400 ft. in the 1880 's. The Chicago
or hanging-wall contact vein likewise has no productive history here.
The Indiana vein, hy some regarded as a cross vein cutting off the
Pacific vein on its southward strike and by some as a spur from the
latter, has a shaft connecting with the 950-ft. level of the Pacific shaft,
nearly 1000 ft. south of the latter. Part of the Pacific south ore-shoot
was worked through this Indiana shaft which is kept equipped now
with a hoist.
The ore in the Empire ore-shoot has always been bounded on the
north by a meta-andesite dike entering from the footwall side. This
outcrops 2850 ft. north of the Pacific shaft, and had a thickness of about
100 ft. where crosscuts have passed through it. The gouge and ore
stop at this dike which persists to the greatest depth yet reached. In
the lower levels the andesite turns away from the shaft on a curved
course indicating that it may be lens-shaped. On the 4450-ft. level the
northern end of the orebody is now 800 ft. north of the main shaft.
Ore-shoots appear to have occurred at and near vein intersections
or the junctions of spur veins. Contact zones between the slate and
PHYSICAL SCIENCES LIBRARY
UNIVERSITY OF CALIFORNIA
DAVIS, CALIFORNIA 95616
WALTER W. BRADLEY, STATE I
Manposd (Jurassic) C/ay S/a^e
■:;:;:;:;:;:;:;:i fmp/re Locfe Ore Shoofs.
>' Afp//7G Ancfesffe Df^e or 5///.
MOTHER LODE GOLD BELT 111
interbedded andesites seem to have been a controlling factor in
determining the location of veins, as well as of ore-shoots. The acci-
dental occurrence of open spaces in the main fault fissures or adjacent
spurs was another factor.
Equipment
Some of the equipment for mining and milling formerly in use
has been removed or has deteriorated, but larger items are intact.
These include 30 stamps, 4 Hardinge mills, Nordberg hoist with 500 h.p.
motor, 3 compressors with motors of 400, 75 and 160 h.p., respectively,
steel head-frame, rock breaker, 3 air receivers, 7 transformers, about
20 electric motors, timber framing equipment, drill sharpener, etc.
The hoist building and some others are in good shape, but the mill is
not. There are 5 dwellings belonging to the company. The method of
ore treatment has often been described and is alluded to under Metal-
lurgy.
Seaton (Peerless) Mine, a mile east of Drytown and adjoining the
Maryland on the south, covers 1260 ft. along the east side of the lode,
in the strike of the Loyal Lead. Previous to 1868, the Seaton had been
opened to a depth of 500 ft. and it was stated had produced 10,000
tons of ore that yielded $9 a ton. The 40-stamp mill was later burned
and the mine lay idle for many years; in two later short periods of
activity it was reopened and the shaft was sunk to a depth of 950 ft. on
an incline of 65° and a length of 600 ft. was prospected. Another shaft
was sunk 500 ft. There is no record of further production, though
the total up to 1885 is claimed to have been important. The vein at
the surface has a Mariposa slate footwall and greenstone hanging wall.
On the 800-ft. level the width was reported two ft.
South EureJia Mining Company owns 401 acres, including practi-
cally all mineral rights between the Kennedy and the Central Eureka
and covering the Oneida and South Eureka Mines.
History and Production
The Oneida was one of the richest of the early-day producers. The
ore on the hanging-wall side was the best, yielding $30 to $40 a ton,
according to J. Ross Browne.^ The average yield in 1867 was $22 a
ton and in 1868 it was $16 a ton.- In 1871 there were three shafts,
300, 700 and 800 feet deep, respectively. The vein was drifted for a
length of 800 ft. on the 700-ft. level, and the ore-shoots were said to
have been 700 ft. and 400 ft. long. These old workings finally reached
a depth of about 1000 ft., after which the property lay idle until 1896.
In that year a new vertical shaft was started and it was expected this
would strike the vein at a depth of 1750 ft., but on account of the vein
assuming a steeper dip, it was not struck until the 1900-ft. level. This
shaft reached a depth of 2280 ft., and an inclined winze was sunk 250 ft.
deeper at a point 280 ft. north of the shaft. The mine was worked
extensively from the 1200-ft. to the 2200-ft. level. On the 1200-ft.
level, the vein was drifted 2700 ft., on the 1500-ft. level 2050 ft., and
on the 2000-ft. level about 2300 ft. Ore was stoped from the latter
1 Mineral Resources of the U. S., West of the Rocky Mountains, 1868.
2 Raymond, R. W., Mineral Resources of the U. S., West of the Rocky Moun-
tains, 1869.
MOTHER LODE GOLD BELT 111
interbedded andesites seem to have been a controlling factor in
determining the location of veins, as well as of ore-shoots. The acci-
dental occurrence of open spaces in the main fault fissures or adjacent
spurs was another factor.
Equipment
Some of the equipment for mining and milling formerly in use
has been removed or has deteriorated, but larger items are intact.
These include 30 stamps, 4 Hardinge mills, Nordberg hoist with 500 h.p.
motor, 3 compressors with motors of 400, 75 and 160 h.p., respectively,
steel head-frame, rock breaker, 3 air receivers, 7 transformers, about
20 electric motors, timber framing equipment, drill sharpener, etc.
The hoist building and some others are in good shape, but the mill is
not. There are 5 dwellings belonging to the company. The method of
ore treatment has often been described and is alluded to under Metal-
lurgy.
Seaton (Peerless) Mine, a mile east of Drytown and adjoining the
Maryland on the south, covers 1260 ft. along the east side of the lode,
in the strike of the Loyal Lead. Previous to 1868, the Seaton had been
opened to a depth of 500 ft. and it was stated had produced 10,000
tons of ore that yielded $9 a ton. The 40-stamp mill was later burned
and the mine lay idle for many years; in two later short periods of
activity it was reopened and the shaft was sunk to a depth of 950 ft. on
an incline of 65° and a length of 600 ft. was prospected. Another shaft
was sunk 500 ft. There is no record of further production, though
the total up to 1885 is claimed to have been important. The vein at
tlie surface has a Mariposa slate footwall and greenstone hanging wall.
On the 800-ft. level the width was reported two ft.
South Eurelia Mining Company owns 401 acres, including practi-
cally all mineral rights between the Kennedy and the Central Eureka
and covering the Oneida and South Eureka Mines.
History and Production
The Oneida was one of the richest of the early-day producers. The
ore on the hanging-wall side was the best, yielding $30 to $40 a ton,
according to J. Ross Browne.^ The average yield in 1867 was $22 a
ton and in 1868 it was $16 a ton.^ In 1871 there were three shafts,
300, 700 and 800 feet deep, respectively. The vein was drifted for a
l^^ngth of 800 ft. on the 700-ft. level, and the ore-shoots were said to
have been 700 ft. and 400 ft. long. These old workings finally reached
a depth of about 1000 ft., after which the property lay idle until 1896.
In that year a new vertical shaft was started and it was expected this
would strike the vein at a depth of 1750 ft., but on account of the vein
assuming a steeper dip, it was not struck until the 1900-ft. level. This
shaft reached a depth of 2280 ft., and an inclined winze was sunk 250 ft.
deeper at a point 280 ft. north of the shaft. The mine was worked
extensively from the 1200-ft. to the 2200-ft. level. On the 1200-ft.
level, the vein was drifted 2700 ft., on the 1500-ft. level 2050 ft., and
on the 2000-ft. level about 2300 ft. Ore was stoped from the latter
1 Mineral Resources of the U. S., West of the Rocky Mountains, 1868.
2 Raymond, R. W., Mineral Resources of the U. S., West of the Rocky Moun-
tains, 1869.
112 AMADOR COUNTY
level to the old workings. A GO-stamp mill was used. Operations con-
tinued until 1913, since when the mine has lain idle except for some
work done through the South Eureka shaft.
Only fragmentary figures are at hand for the earlier production.
For eight months prior to June 1, 1867, a yield of $135,000 from 7710
tons of ore was reported, at a cost of $5 a ton. For less than four
months in 1868 the output was $60,400 from $16 ore. The mine at that
early date had 60 stamps ; 40 weighed only 450 lb. each and 20 were of
650 lb. weight. By 1872 the average yield had dropped to $10 a ton.
For the period from 1898 to 1910, inclusive, the production was
about $1,500,000. The yield during this time was from $2 to $3.75 a
ton. The total production before sale to the South Eureka Mining
Company has been estimated at $2,500,000.
The South Eureka lay undeveloped until 1891, due probably to the
fact that most of the surface along the course of the Mother Lode fissure
through the property is covered by andesite cobbles. In that ^''ear an
inclined shaft was started which finally reached a depth of 2785 ft.
To a depth of 900 ft. the fissure was filled principally with crushed
slate and gouge, containing only a little quartz. The ground was very
heavy and the shaft expensive to keep open on account of having been
sunk in this crushed slate. On the 900-ft. level, a crosscut revealed
some ore on the east contact (hanging wall) of black slate and green-
stone, but for the most part the ore was scattered in bunches in the
gouge-filled fissure and did not make a good-sized or profitable ore-shoot.
For ten years assessments were levied to continue prospecting. During
this period a 20-stamp mill was in use part of the time. After 58
assessments had been levied and the 2740-ft. level had been reached,
a crosscut to the footwall encountered an important ore-shoot. This
was subsequently developed by crosscuts from the higher levels, and
was stoped up to about the 2000-ft. level. The mill was increased to
80 stamps and the property for several years was one of the largest
producers of the county, employing from 200 to 250 men. They quit
in 1918.
In 1921, the Central Eureka Mining Company took an option on
the property and extended several of their deeper levels into the South
Eureka. The 3350-ft. level south drift was run to a point 120 ft. north
of where the South Eureka shaft would be if continued. A west
crosscut was run in greenstone near the north end-line of the South
Eureka on this level. On the 3900-ft. level, the drift was extended
about the same distance into the South Eureka, and a crosscut was run
east in slate 740 ft. This cut several gouge seams and vein formations
but no ore was found. The 4100-ft. level was also run into the South
Eureka. The result of all this work was disappointing.
Since the South Eureka Mining Company quit, the shaft as far
far down as the 2740-ft. level, and the workings connecting the two
mines on that level (Central Eureka's 2540-ft. level) and on the 1800-ft.
level (Central Eureka's 1600-ft. level) have been kept in repair by the
Central Eureka Mining Company. Water from the lower part of the
Central Eureka Mine is pumped to their 2540-ft. level and piped thence
to the South Eureka pump station which is maintained and operated
by the Central Eureka Mining Company. The South Eureka shaft,
MOTHER LODE GOLD BELT 113
over wliich the hoist is kept in running order, also serves as a second
exit.
From 1895 to 1908, inclusive, the property was only a moderate
producer from the small orebodies of the hanging-wall vein. This
ore ranged from $2 to $6 a ton in yield and the total output was about
J^l,200.000 for this period, representing the exploitation of the hanging-
wall vein from the 900-ft. to 2700-ft. level.
Following the discovery of the footwall vein system in 1908, the
mine at once became an important producer. The 20-stamp mill not prov-
ing sufficient, at first 10 stamps of the Central Eureka Mill were rented,
and then the South Eureka mill was increased to 80 stamps. Dividends
began in 1909 or 1910. There was a gross production of about $4,100,-
000 from over 980,000 tons of ore from 1909 to the time of closing in
1917. The total amount of dividends is not known, but if local reports
are to be relied upon, must have been about $1,000,000. Operating
costs were relatively low. In 1911 mining and milling cost was said
to be $2.63 a ton and monthly dividends of $21,000 were reported.
In 1915, operating cost per ton milled was $3,275 and dividends for
the year were said to be $125,354.
Geology and Mine "Workings
On account of the outcrop of the lode being covered on the South
Eureka by the capping of an ancient stream channel, the surface gave
little encouragement for quartz prospecting. The sinking of the shaft
was therefore a speculative venture, based on the position of the claims
between known producers on a well-defined gold-bearing structure.
Two lines were surveyed across the property following the direction
of strike of the lode as exposed in the Eureka mine on the north and
in the 1650-ft. level of the Kennedy on the south. These proved to be
about parallel and 100 ft. apart on the surface of the South Eureka.
Midway between the lines an inclined shaft was started in the black
slate which was soft, crushed and hea^'y. It proved to be expensive to
keep open, requiring continuous retimbering and realigning. Cross-
cuts were run to the hanging-wall greenstone at 500, 600 and 900 ft.
inclined depth. The work to a depth of 900 ft. gave little ore, as
previously noted. The crosscut at 900 ft. showed an ore-shoot up to
5 ft. wide at the contact. The greenstone on the hanging-wall side
of this had been sufficiently mineralized to become ore, and on the
footwall side of the vein there was also a "rich pay streak from 1 inch
to 10 inches in width, heavily sulphuretted and high grade." In 1900
the shaft had reached 1800 ft. in length. The vein was reported much
disturbed by faults, with rich ore occurring in bunches in the slaty
gouge.
The beds of Mariposa slate in which the ^Mother Lode occurs here
lie between two belts of greenstone. The shaft cut the hanging wall
vein at the 1700-ft. level and followed it to the 2000-ft. level, near
which this vein entered the greenstone and the shaft passed into the
slate. The slate belt is several hundred feet wide. The so-called
footwall vein is one of several worked in the lower levels. It was
found by following a spur or link vein from the contact region into the
slate where it joins the footwall vein which is about 250 ft. west of the
8 — 4156
114 AMADOR COUNTY
contact. It was followed upward from the 2740-ft. level to above the
2000-ft. level.
In winzes and drifts below the bottom of the shaft it was found
the main ore body was only 60 ft. long on the.2900-ft. level. It raked
north and crossed the line into the Central Eureka on the latter 's
2700-ft. level, but went only 30 ft. below there.
The mill contained eighty 1,150-lb. stamps, dropping 6^ inches 100
times per minute and crushing five tons each daily through 24-mesh
screen. After outside amalgamation, the pulp passed to 48 six-ft. Frue
vanners. The saving was from 85% to 91%. Concentrate formed
from 1.7% to 2% of the ore, and carried from $60 to $72 a ton in gold
and 40 to 65 cents in silver. •
South Jackson Mine, one-half mile south of Jackson, was worked
by a company of the same name from 1912 to 1915. It is on an agricul-
tural patent (Meek Ranch) covering part of the eastern band of
Mother Lode slates. Three stringer leads were prospected. A vertical
shaft was sunk 577 ft. with levels at 210, 345 and 500 ft. On the
210-ft. level a crosscut was run 90 ft. west. On the 345-ft. level a west
crosscut 280 ft. long cut a vein 80 ft. from the shaft, and this was
followed north 312 ft. and south 383 ft. showing 5 ft. of quartz in each
face. On the 500-ft. level a crosscut was run 1035 ft. east cutting the
middle vein 20 ft. from the shaft ; this vein was drifted on 260 ft. north
and 130 ft. south. A vein which they called the Zeila was struck in
this crosscut 750 ft. east of the shaft and a drift was run north 100 ft.
on it.
In January, 1915, South Jackson Mining Company announced
they had spent $104,000 but were disappointed with the results of their
work, as the amount of ore found did not justify a plant. After crush-
ing less than 200 tons of ore at a custom plant that year, they closed
the property which has since been idle.
South Keystone Consolidated Mining Company. This was the
company which did considerable work in 1917 and 1918 on the North
Star (which see), Boyson and South Keystone claims. They made no
production.
Valparaiso Mine is on a narrow strip of Mariposa slate enclosed in
the greenstone and extending from the Argonaut Mine to Spanish Gulch
where it joins the main slate belt. The mineral zone along this slate
and its contacts is locally called the 'black metal belt' because the
gold is coated black and possibly because of the rich sulphides, often
carrying much more gold than usual on the lode. The Mammoth Mine
adjoins on the south. The gold occurrence is pockety.
An adit 1300 ft. long was completed on the Valparaiso claim in
January, 1888, and the three men who drove it were each given a
one-twelfth interest in the claim for their work. It extended to within
200 ft. of the south line. A Huntington mill was put on the claim the
same year. It was thought at the time that a rich and well-defined
ledge lay in the hanging wall of this adit. The later production, how-
ever, was in the form of small tonnages of fair to high-grade ore. No
record is at hand of the first ten years' output after 1888. From 1898
to 1931, inclusive, the Valparaiso is credited with a production of over
$100,000. The estimated value per ton of the ore milled ranged from
$9 to $500, as much of the gold came out in the form of 'pockets' or
MOTHER LODE GOLD BELT 115
'specimens' and the ore crushed was the residue mined in cleaning
up around such bunches. Some winze workings and exploratory cross-
cuts were driven in later years. The concentrates from this mine are
reported to have carried at times as much as 37 ounces of gold per ton
and formed 5% to 6% of ore.
The geology is very similar to that of the Amador Queen No. 2 and
Mammoth Mines.
Zeila Mine (originally called the Coney) is at the southeast side
of Jackson, and the original mining claims with mineral rights acquired
on ranch lands cover a mile along the contact of greenstone and Cala-
veras schist.
In the 1860 's it had been worked to a depth of 200 ft. and for
300 ft. on the strike. There was a 16-stamp mill in 1867 and the ore
at that time was said to be yielding $13.50 a ton, of which $6 a ton
was said to be in free gold. A chlorination plant had already been
erected to treat concentrate, which was said to form 5% or more of ore.
By 1875, however, after a depth of 600 ft. had been reached, work had
been stopped and the mill had been dismantled, because of * ' refractory
rock." It was reopened about 1880 and was a producer every year
until 1914, since which date it has lain idle and has passed into the
possession of the Kennedy Mining and Milling Company.
Few details were ever given out concerning the results of operation
and as is natural in such cases the output of the property has been
overestimated. Because of the low grade of ore and the size of ore-
body, there was a certainty of performance which made for low cost of
operation, and if the figures for the Zeila were obtainable, they would
probably prove as low as, if not lower than any others for operation at
any considerable depth on the Mother Lode. W. F. Detert boasted that
although the Zeila was never even a $4 proposition (during his time)
it had been a steady dividend payer ever since it was placed under his
management. The output was about $5,000,000 for the 34 years ended
in 1914, and in the later years at least, the average recovery was
between $3 and $4 a ton. The stock was closely held and the amount
of dividends was never revealed. A 40-stamp mill was operated most
of the time.
Geology and Mine "Workings
No reports on the mine have been printed since about 1900. In
1890, Fairbanks stated (Report X of the State Mineralogist) that
"At the Zeile there are several veins worked. The hanging walls are usually
of decomposed dikes. The character of the rock worked Is somewhat similar to
that of the Amador Queen — alternations of gray slates, small veins, and a decom-
posed crystalline rock. The whole of the rock is filled with stringers of quartz and
the greater part of it is milled. The gouge on the footwall of the main vein of the
Zeile varies from a few feet to fifty feet. There is no gouge on the lianging wall,
and the horse is always from that wall. The best paying portion is the ribbon
quartz."
According to Folio 63 of the U. S. Geological Survey,
"The vein is essentially a stringer lead in amphibolite schist and has a general
dip of 50° to 60° E. It is separated from the black slates (Calaveras formation) of
the footwall by a hea\'y gouge. The width of the vein where sloped is 40 to 50 feet,
but the general average is somewhat less. A fine-grained, altered dike, from 4 to 6
feet wide, probably originally a diorite, accompanies the vein. The ore is of low
grade — less than $4 per ton. Pyrite is the principal sulphide, but there is sometimes
a little molybdenite, and small quantities of galena and zincblende are said to occur
and to indicate good ore. Calcite is quite abundant, both as stringers and crystal-
lized with the quartz."
116 AMADOR COUNTY
The shaft was sunk 1700 ft. on an incline of 65°. The 1570-ft.
level drift was run nortli 3000 ft., and on that end a winze was sunk
458 ft., with levels at 157 and 295 ft., which were also drifted north,
the latter 450 ft. At the time of closing it was stated the mine con-
tained 360,000 tons of ore averaging less than $4 a ton. It was stoped
out from the 1200-ft. level to the surface, north of the shaft, where the
ore-shoot was 600 ft. long and averaged 20 ft. wide.
The mill of 40 stamps in the most productive years crushed from
60,000 to 65,000 tons of ore annually with an annual output that only
once exceeded $200,000. The concentrate formed from 2% to 2.3%
of ore, and yielded from $68 to $93 a ton. This concentrate carried
from one-half to over tw®-thirds of the gold, and was treated by
chlorination at the property.
MOTHER LODE GOLD BELT
117
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AMADOR COUNTY
Mother lode gold belt 125
CALAVERAS COUNTY
Geology.
The most productive sections of the Llother Lode in this county are
the ones extending from Stanislaus River to the north slope of Carson
Hill, and that within the townsite of Angels Camp. In the first, the
ores occur in or near altered intrusives occupying contact areas
between the amphibolite schist and the Calaveras formation. At
Angels Camp the mines were found in profoundly altered and silicified
amphibolite schists. (See Utica and Gold Cliff Mines.) The more
important mines of Angels Camp were all in a block of country bounded
on the north by a fault crossing the course of the lode and dipping
southeast. West and northwest of Angels Camp, mineralization occurs
over a width of more than two miles, in which many small mines but
5^0 large orebodies have yet been ft)und. Characteristic of this
zone are 'stringer leads' of quartz and calcite, with occasional pockets,
in amphibolite schist. A few miles northwest of Altaville, there is a
group of small mines in the Calaveras slates which show well-defined
veins. Among these are the Shotgun, Demarest and Thorne. From
Altaville to the vicinity of San Andreas mines and prospects are
scattered along a northwestward course in amphibolite schist. It is not
until the Gwin Mine is reached, near the northern end of the county,
that the lode re-enters the Mariposa clay slate. This mine is on the
extreme west side of the slate belt, in a lens of slate about one-quarter
of a mile wide, with altered andesite on both sides, and is similar geo-
logically to the important mines at Jackson and Sutter Creek.
Mokelumne Hill district, which is at the southeast end of a batho-
lith of diorite with an area of about six square miles, is east of the
course of the Mother Lode, but has many quartz mines, some of which
have been important producers.
Geography, climate, water, power, timber.
Calaveras shares with the counties north and south a gently rolling
topography in the Mother Lode section. There are no important
streams crossing the lode between the north and south county-lines,
which are formed by the Mokelumne and Stanislaus Rivers respectively.
Occupying as they do, deep canyons w^hich they have cut transversely
across the course of the Sierra Nevada 's western slope, they have neces-
sitated expensive installations for water and hydroelectric power sup-
ply. Carson Hill, the principal outstanding topographic feature of the
lode in this county, rises to an elevation of about 1900 feet, over 1100
feet higher than Stanislaus River which flows by it on the south.
This hill and Chaparral Hill owe their heights to the resistant character
of the massive 'bull quartz' outcrops so common farther south. Else-
where the lode traverses rolling land carrying sparse digger pine, small
oaks and some brush.
Angels Camp, elevation 1535 feet, has a rainfall varying from 20
to 54 inches annually, most of this falling as a rule between November
first and May first. Orange trees have grown and borne fruit for many
126
CALAVERAS COUNTY
years at Mokelumne Hill, 1550 feet elevation, where the mean minimum
temperature over a period of 17 years never dropped below 36.8° F.
Water for mining has been supplied in the Angels Camp district
by Utica Mining Company. The same company, and Pacific Gas and
Electric Company, supply electric power to the mines, the latter com-
pany having a hydroelectric plant near the north county-line.
The lode is below the line where good timber grows, and nearby
stands on the foothills have been cut ; but there is plenty of good pine
(largely yellow pine) in the higher hills within a short truck-haul to
the east.
Transportation.
Sierra Railway of California serves the Carson Hill and Angels
Camp districts with a branch line from Tuolumne County. The north-
ern end of the lode is served by a branch of the Southern Pacific Rail-
road to Valley Spring.
Analysis of Gold Production, Calaveras County, 1914-1933, Inclusive
County's
total
gold*
Mother Lode mines
Year
Tons ore
Average
per
ton
Gold per
ton of
concentrates
Mother
Lode
gold
19)4
$1,336,875
1,391,134
1,356,120
1,471,442
871,263
1,550,574
1,439,745
1,495,758
1,413,465
1,205,784
853,961
652,433
576,889
219,217
162,372
103,843
112,913
152,771
186,378
358.231
358,436
369,569
402,278
393,883
306,510
152,862
126,800
182,015
183,733
172,237
142,078
107,542
92,798
792
1,516
Pockets
576
Pockets
Pockets
'36,000
$2 22
2 28
2 13
2 04
2 08
8 14
9 13
5 92
5 76
5 76
5 OS
4 96
5 07
17 69
9 87
$23 99
37 92
36 10
13 44
20 20
45 08
57 51
56 77
54 91
52 43
68 22
65 62
77 45
93 36
$797,267
1915
844,610
1916
857,583
1917
805,323
1918 --- ---
638,626
1919
1,244,130
1920
1,157,983
1921... .
1,078,698
1922 --
1,058,920
1923
992,625
1924 ---
722,847
1925
533,803
1926—
470,844
1927
14,017
1928
14,976
1929
5,388
1930
6 63
3,820
1931
5,472
1932
1933
■1 80
'65,000
* All gold values in this report are figured on a value of $20.67 a Troy ounce.
' Estimated, 1933.
MOTHER LODE GOLD BELT
127
Angels Mine at Angels Camp is an interesting example of a small
Mother Lode mine which was operated at low cost on varying grades
of ore over a lengthy period, because of careful management.
The claim from which the later consolidation took its name was
first worked in the late 1850 's and before 1870 had been worked to a
depth of 186 feet and for a length of 350 ft. The ore in 1867 was
said to yield only $8 a ton though assaying $15 to $20.
Gold and Silver Production of Calaveras County, 1880-1933
Year
Gold,
value
Silver,
value
Year
Gold,
value
Silver,
value
1880
1320,865
800,000
670,000
500,000
485,000
527,538
639,457
640,417
580,000
592,243
618,821
738,883
794,531
1,669,192
2,119,365
1,717,916
1,546,398
1,439,861
1,019,023
1,265,564
1,649,126
2,024,685
2,072,939
1,904,125
1,789,184
1,836,816
1,644,234
1,097,974
1643
1,200
1908
1909
$1,378,511
1,440,511
1.147,705
1,112,315
962,145
1,175,208
1,336,875
1,391,134
1,356,120
1,471,442
871,263
1,550,574
1,439,745
1,495,758
1,413,465
1,205,784
853,961
652,433
576,889
219,217
162,372
103,843
112,913
152,771
186,378
442,980
$62,727
1881
71,418
1882
1910.
82,866
1883
1911
1912
67,032
1884.
70,748
1885
1886.
2,558
4,926
1,477
1,500
1,071
2,499
4,860
24,441
122
5,183
77
500
1,745
3,462
9,813
80,762
44,687
46,234
68,280
65,611
78,859
74,099
54,420
1913
1914
1915
1916
1917... ...
61,076
60,442
1887
53,298
1888
83,643
1889 .
87,984
1890
1918
84,150
1891
1892
1919
1920
1921
35,876
16,701
1893
10,232
1894
1922
1923 --
11,648
1895
7,316
1895
1897-
1924 -
1925..-,
1926..
7,463
8,324
1898 -.
6,229
1899
1927
1928
1929---
3,982
1900
1,469
1901
3,444
1902
1930 -
1,555
1903.-
1931
989
1904
1932
763
1905
1933
1,937
1906..
1907
Total values
$56,916,469
$1,482,341
The Doctor Hill claim had also been worked seven years between
1857 and 1867. Although it was said it had yielded $250,000 this was
less than had been spent on it. Both these mines were working a vein
15 ft. wide in the schist. By 1884 the Doctor Hill had been opened to
a depth of 150 ft. where the vein was reported 13 ft. wide, of which 3 ft.
was said to be verv^ rich and the balance worth $10 to $12 a ton.
Billings, Crystal, Oneida, Doctor Hill, McCormick, Beda Blood,
and Angels claims were grouped by Angels Quartz Mining Company in
1886 and this company operated continuously until March 1, 1918 since
which date no work has been done. The total production of the prop-
erty is not known. From 1900 to 1918 inclusive the output was about
$2,000,000 from ore averaging from $2 to $10 a ton.
The later work was through the Angels shaft 850 ft. deep, from
the lowest level of which a winze was sunk 200 ft. and the vein
developed on the 1050-ft. level. The ore found on that level was con-
sidered to be too far from the shaft to be worked at a profit. A cross-
cut was run east 800 ft. from the 850-ft. level and a rich, narrow vein
was mined for a length of 400 ft. It was followed both up and down
until it pinched to a seam. Although the ore from this vein did much
to 'sweeten' the mill-heads, the bulk of tonnage came from the
stringer leads in the amphibolite schist. Two of these, called Mother
Lode and East veins, were worked. The former was worked in places
128 CALAVERAS COUNTY
20 ft. wide by shrinkage sloping. The footwall was hard diorite and
hanging wall heavy, talcose schist. During the last operations ore was
taken from the 200-, 400-, and 500-ft. levels. Stopes were from less
than 100 to 200 ft. long. Crystal shaft, 600 ft. deep, on the west vein
had been sunk 600 ft. but in the later years was used principally as
a second entry.
The so-called talc or 'bull quartz' barren zone was cut in the
Angels shaft at a depth of about 400 ft. It dipped east 45° and was
cut again in the east crosscut on the 850-ft. level 400 ft. from the shaft.
The ore from this mine was crushed in a mill of forty 850-lb.
stamps and Frue vanners were used for concentration. An extraction
of 90 per cent was claimed.' Concentrate formed 1^ to 2 per cent of
ore and yielded $38 to $70 a ton. The mill handled about 200 tons
a day.
This company claimed an operating cost of $2.25 a ton in 1913.
Big Spring (Graham) Claim covers 1200 ft. in length on the Bull
Quartz vein IJ miles south of Angels Camp, This vein strikes about
N. 20° W. and outcrops continuously throughout the length of the
claim. The work has been superficial, in search of pockets, and the
greatest depth reached was only 75 to 100 ft. in a shaft long since
caved,
Demarest, McCauley, Pioneer, Martinusen, Johnson, Hale and
Smyth claims, composing the old Brovm-Smyth-Ryland Consolidated
and adjacent ground, was last prospected in 1920-1921 by Angels
Camp Deep Mining Company. The claims adjoin the Lindsay claim of
Utica Mining Company on the east and northwest. The early-day
production of these claims, from shallow workings, is unknown. From
1889 they made some small and irregular output. The Pioneer shaft
was 187 ft. deep with 487 ft. of crosscuts and Smyth shaft was 140 ft.
deep, with two levels and 692 ft. of crosscuts, before the last company
started work. They deepened Pioneer shaft to 500 ft. on an angle of
83° with levels at 300, 400, and 500 ft.
The stringer lead formation was from 5 ft. to 32 ft. wide in
different workings. About 1600 ft. of new drifts and crosscuts were
run, but the small tonnages of material milled were not on the average
of payable grade.
A 20-stamp mill which had been put on the claims in 1921 was sold
in 1929 and removed to the Osborne property.
Bruner, St. Lawrence or Bald Hill Mine, two miles south of Angels
Camp, comprises eight claims. Apex, Evening Star, De Wet, Spring
Gulch, Cold Hill, Eomaggi & Costa, Bald Hill and New Discovery. In
1897, the Bald Hill was worked in a small way by F. Bruner, who
hauled ore to the TuUoch mill. Previously, this claim had been pros-
pected to a depth of 300 ft. (incline) but there is no record of the
results. In 1899, it was taken over by others and named the St,
Lawrence. By 1900, ihe shaft had reached a depth of 400 ft. on an
incline of 64° with levels at 100 ft. and 400 ft. in depth. There are no
records of the results obtained. More work was done in 1913-1914
when mining equipment was installed but no ore was crushed.
The property was worked for placer and gold pockets in early
days.
MOTHER LODE GOLD BELT 129
Carson Hill Mines, now being operated by Carson Hill Gold Min-
ing Corporation, include Melones, Morgan and Calaveras mines all
with separate former histories, extending from the Stanislaus River
at Melones to the Bright Star claim of the Chaparral Hill group,
including the Morgan, Union, Kentucky, Iron Rock, Relief, Reserve,
Enterprise, Irvine, McMillan, Santa Cruz, Calaveras and other claims,
covering about a mile and a half on the strike of the lode.
History and Production.
Morgan Mine was discovered in 1850 by Hance who took in six
partners, one named Morgan. The claim lies on the northwest side of
Carson Hill and was only 550 ft. long, but was so rich that it attracted
thousands to the camp. The largest single piece of quartz gold (va^ue
$43,534)^ ever reported is claimed to have come from this mine. It is
said to have been about five inches in diameter and four to five feet
long, and was part of a $300,000 pocket. The ore that was not rich
enough to be worked in hand mortars was crushed in arrastres run by
Mexicans, who were the only miners there who had had any previous
experience in such work. In 1868 - it was stated that the mine was
locally credited with a known yield of $2,800,000 between February,
1850, and December, 1851, besides which large sums were supposed to
have been stolen by Mexican 'high-graders.' In 1852 a band of several
hundred outlaws seized the mine, drove off the owners, and worked it
nine months until stopped by injunction. Thereafter, not much mining
was done until 1867. This report stated the claim contained two veins
which united 100 ft. below the surface. They were the stratified vein
(ribbon rock) 6 ft. wide, and the boulder vein ('bull-quartz' vein)
40 ft. wide. The mine in 1867 had been opened only to a depth of 100
ft. where the ore-shoot was 200 ft. long. The boom had collapsed with
the exhaustion of the specimen ore.
By 1898, a total depth of 500 ft. below the outcrop had been
reached, with an adit and a winze sunk 200 ft. from its floor. The ore
found in this work was reported worth only $3 to $5 a ton. Little
more was heard of the mine until 1919, when Carson Hill Gold Mines,
Inc., which had been working the adjoining Calaveras Mine, made a
discovery in the Morgan. In crosscutting through the hanging wall
of the 'bull quartz' vein they found a rich vein on the 300-ft. level.
They began milling in 1919, stoping up to the 200-ft. level, and sinking.
For 1919, the millheads were reported to have averaged $14.95 a ton
for the first 60,000 tons crushed. Development was rapid. A new,
large mill was built at Melones and after 1921 it handled from 9,000
to 15,000 tons of ore a month. Melones mine, which had been closed
down by its former owners in 1918, was taken over, and its workings
were utilized for handling the Morgan ore; and, as the Morgan ore-
shoot passed into the Melones Mine because of its southerly pitch,
the scene of operations moved into the latter mine below the 1450-ft.
Morgan level. The former company had previously mined on the
hanging-wall side of the 'bull-quartz' vein from their 1350-ft. to 3500-
ft. levels. The later operations of Carson Hill Gold Mines, Inc., were
on lower-grade ore than had been mined in the Morgan. 'Flat veins
1 Hanks, H. G., Report of the State Mineralog-ist, Vol. II, p. 148, 1882.
2 Browne, J. Ro.ss. Mineral Res. of IT. S., West of the Rocky Mountains.
9 — 4156
130
CALAVERAS COUNTY
which cut at a flatter angle across the hanging-wall vein and 'bull
quartz' vein, furnished part of the tonnage in later work.
The production from the Morgan ore-shoot can not be exactly
stated without examination of the company's detailed records, as part
of the time ore w^as mined and milled from the Morgan and Melones
Open cut or g-lory hole on Morgan claim of Carson Hill Co.
Upper bench is site of old Fair shaft near which famous
$300,000 pocket was taken out in November. 1854, including
one mass weighing 2340 ounces Troy, valued at $43,534
(State Mineralogist's Report II, 1882). Note figure of man
in lower center.
Photo by Walter W. Bradley, May 2i, 193.'t.
mines simultaneously, including a good deal from the 'flat veins'; and
the Calaveras mine produced small tonnages during several years up to
1925. From the beginning of 1919, when milling of the Morgan ore-
shoot started, to the end of the company's operations in 1926, the
production was as follows. Probably $4,500,000 or more of this was
from the Morgan ore-shoot.
MOTHER LODE GOLD BELT 131
Work finally reached an inclined depth of 4550 ft. (see under
Geology and Mine Workings) under Melones Mine. There is no record
of any dividend having been paid and stockholders lost their equity
when the bondholders ordered sale of the property, bonds amounting
to $499,200. The combined properties were again formally placed
on production September 4, 1933, by the present company. The first
bullion was shipped in October. During October, 10,581 tons of ore
was milled and was reported as yielding 870 fine ounces of gold. In
November, 11,355 tons is said to have yielded 1026 fine ounces. During
Production of Carson Hill Gold Mines, Inc., 1919-1926
Year Tons Ore Gold Silver
1919 77,ST1 $1,024,616 $6,525
1920 105,152 1,093,900 7,195
1921 175,755 1,059,989 7,257
1922 183,733 1,058,920 8,776
1923 172,066 990,716 5,371
1924 140,098 716,112 3.528
1925 107,440 531,699 2,898
l;»26 92,698 460,846 2,131
1,054,813 $6,936,798 $43,681
eight months since reopening the production is reported to have been
over $300,000. The ore being milled in September was reported as
coming from four flat veins between the 875- and 1600-ft. levels in the
Morgan and Melones mines ; the 500-ft. level of the Calaveras mine and
the Morgan glory hole. Later a gasoline shovel was placed on the Santa
Cruz claim of the Calaveras Mine, and has been supplying a large part
of tonnage milled. This ground had been extensively sampled by the
former operators, before they discovered the rich Morgan ore-shoot.
The old 1100-level Melones tunnel has been repaired and connected
with the upper workings and electric haulage with a 5-ton locomotive
has been installed in it, capable of handling a load of 100 tons. A total
crew of about 160 men has been employed during the spring.
When the property was visited late in June, 1934, ore was coming
from wdthin the limits of the development work done by former
operators.
On the Santa Cruz claim, a width of 20 to 40 ft. of schist was
being mined by power shovel on the hanging wall side of the Calaveras
vein. This was supplying from 150 to 200 tons in 8 hours which was
hauled in trucfe carrying 3J tons about one mile to a loading chute.
Thence it went by trolley locomotive to the mill in trains of 56 tons
each.
The Morgan glory hole was reported to be supplying 300 tons a
day to an ore-pass which dropped it to the 1100 level adit. From
there it was being hauled by trolley locomotive a mile to the mill.
Ore was also reported in the hanging wall vein on the 675-ft. level
on the Morgan claim north of the old high-grade ore-shoot, and on the
hanging wall of the 'bull quartz' vein from the 800- to 1600-ft. level.
The mill used by the last company has beeen rearranged in part
and it was claimed it was handling ore at the rate of 20,000 tons a
month in June, 1934. This mill retains tlio practice of coarse crushinsr
w'ith stamps followed by Ilardinge mills, introduced by Loring. The
approximate flow sheet is shown under Metallurgy, post.
132
CALAVERAS COUNTY
Geology and Mine Workings.
Rich milling ore was found in the Morgan Mine in 1919 on the
hanging-wall side of a 'bull quartz' vein on the 300-ft. level. The
veins on the Morgan have been regarded as a branch of the Mother
Lode, the main section passing through the Calaveras claims. This
vein system, entering the Morgan from the Reserve claim of the
Melones group, with a nearly westerly strike, curves and strikes nearly
north on the Morgan and Union claims, dipping east 50° to 70°. The
Morgan orebody occurred on the inside or trough of this curve. It
had a southerly pitch which carried it over the south end-line of
the Morgan into Melones ground about the 1450-ft. Morgan level.
The section of this ore-shoot in Melones Mine had been previously
worked between their 1600-ft. and 3000-ft. levels. It was pinched
Mill of Carson Hill Gold Mines, Inc., at Melones, Calaveras County.
(Old Robinson's Ferry.)
PJioto by Walter W. Brndlei/.
below 3000 ft. When opened later by Carson Hill Gold Mines, Inc.,
between 3000 and 4375 ft. inclined depth, it did not show either ton-
nage or gold content comparable to the upper section above the 1450-ft.
level. Though locally termed an altered amphibolite schist, and so
mapped by the U. S. Geological Survey, more detailed study has shown
that on Carson Hill there are various gradations from pyroxene-rich
rocks and others of basic igneous origin to amphibolite schist, chlorite
schist and ankeritized sericite-schist. Knopf ^ states the Morgan ore-
shoot "was not restricted to rock of any one type * * *, The ore con-
sists of sericitic schist composed largely of ankerite with less pyrite,
1 Knopf, Adolph. U. S. Geol. Survey P. P. 157, p. 176.
MOTHER LODE GOLD BELT 133
sericite, quartz and albite." Some galena, chalcopyrite, tetrahedrite,
petzite and free gold occurred. Knopf also mentions molybdenite, and
graphite was seen in places where the vein contained Calaveras schist
or slate.
This ore-shoot had a length of from 140 to 200 ft. to the 425-ft.
level ; was 350 ft. long on the 550-ft. level, and below there to the 1450-
ft. Morgan level had a stope length of from 140 ft. to 315 ft. It
had a maximum thickness of 31 ft. on the 550-ft. level, and the
better-grade ore was there 165 ft. in stope length ; and on the 675-ft.
level, the maximum thickness was 41 ft. This vein dipped on an
average of about 70° to 1350 ft. inclined depth, where one of the
'flat veins' faulted the 'bull quartz' vein 210 ft. eastward. Below there,
the 'bull quartz' and hanging-wall veins had a dip of 50°.
'Flat veins,' filling fault fissures dipping northeast at an average
of about 30° were first struck at 985 and 1350 ft. inclined depth on
the 'bull quartz' vein. They strike N. 70° W. Eventually five such
'fiat veins' furnished ore. The one found at 1350 ft., the so-called
1100 'flat vein,' was the most important. The average stope length
on it from 1100- to 1600-ft. level was 300 ft. or more and the average
width stoped was 10 to 12 ft. This ore in 1924—1925 was yielding an
average of $4.50 to $5 a ton and these veins were then furnishing
about one-third of tonnage milled. This ore differed from that in
the hanging-wall vein, carrying more quartz, but showing altered
schi.st and coarse pj-rite cubes in places.
Other workings on the Morgan mine included the foot wall glorj*
hole, 205 ft. long on the surface and extending to the 200-ft. level where
it is 30 ft. long; and work on the footwall vein, on which a stope
was opened 200 ft. long on the 550-ft. level. The Morgan levels were
from 115 to 125 ft. apart, finally connected by the hanging-wall glory-
hole, 1400 ft. deep. Many thousand feet of north drifts and crosscuts
and raises were run. Below 1450 ft. the work, being in Melones ground,
though now a part of the same property, is described thereunder.
Melones Consolidatecl Mines originally comprised 7 claims, named
Stanislaus, Mineral Mountain, Reserve, Last Chance, Melones, Enter-
prise and Keystone. Most of these claims had earlier histories of
operation before their consolidation about 1895. Stanislans 3Iine,
when worked in the 1860 's, yielded rich ore carrying several tellurides,
including hessite, petzite, altaite, sylvanite and calaverite, apparently
in greater quantity than known elsewhere at the time. The vein,
reported to have had a width of from 20 inches to 6 ft. on and near
the surface, was worked through adits and shallow shafts to a depth of
about 200 ft., where it was said to have broken into stringers.^
Reserve Mine was opened in 1860 and was rej)orted to have pro-
duced $130,000 by 1868, from an adit and a shaft 135 ft. deep. Later
an open cut was made to a depth of about 100 ft. Finally this claim
became the site of the immense open cut through which Melones Min-
ing Company drew so much loAV-grade ore, down to the 1100-ft. adit
level. This was the farthest north of the claims of the latter company,
being nearly a mile north of the river, near the top of Carson Hill.
Here also, in early days, were found several of the tellurides mentioned,
1 Fairbanks, H. W., R. X, State Mineralogist.
134 CALAVERAS COUNTY
ante. Melonite, the telluride of nickel, Nio Teg (with Co, Pb and Ag)
was found only on this claim and was named for it. Tetradymite,
telluride of bismuth, BigTeg also was identified here and in the Morgan
Mine.
Melones Consolidated Mining Company had, in 1898, a length of
5166 ft. on the Middle Vein and 1407 ft. on the Bast Vein. They had
begun prospecting on the Stanislaus claim about 1895 through an adit,
but in 1897 were evidently working principally on the Reserve. A
shaft was sunk there on the East Vein, within 230 ft. of the Morgan
line, to a depth of 200 ft. Drifts and crosscuts gave indications of a
large orebody. The South Cgrolina Mine, adjoining Melones Consoli-
dated on the south on the East Vein, was taken under option. A tunnel
had previously been run 1080 ft. on the South Carolina. Melones Com-
pany continued this to a length of 3030 ft., reaching a point within 40
ft. of the Morgan line, and giving a depth 425 ft. below the 200-ft.
level of Reserve shaft.
In 1899, a mill was started and in 1900 work was well advanced on
the 1100-ft. level tunnel. In October, 1901, this tunnel was 4200 ft.
long, having reached the vein 4000 ft. from the portal. A large project
was also under way to supply water for power designed to operate
under low head, with a flume 3f miles long having a capacity of 5000
miners inches. The first 60 stamps of the mill began crushing rock in
1902. The main adit (1100-ft. level) was eventually extended to 5000
ft. At the place where the adit crossed the vein, an internal shaft 5 ft.
by 17 ft. in the clear was sunk in the footwall on an inclination of 70°
to 1350-ft. level, at which depth one of the 'flat veins' faulted the main
vein 210 ft. into the hanging wall, and the dip of the main vein system
flattened to 50° E. From there to the bottom (3000 ft. under that com-
pany) the shaft was on 50° inclination.
Melones Mining Company operated the mine until 1918 and quit
milling in February, 1919. The footwall vein (on footwall of bull
quartz vein) was worked by caving from surface to 1100-ft. level, the
glory hole having been open this entire depth. From 1350 ft. to 3000
ft. mining was done by shrinkage stoping and mostly on the hanging
wall vein, with ore chutes 40 ft. apart. For some years it was the prac-
tice to take ore during the dry season from the glory hole, and in wet
weather from the lower levels. Melones Company apparently never
discovered the upper part of the hanging-wall orebody ; when this fine
shoot was discovered in the Morgan Mine in 1918-1919, it was separated
from some of the Melones footwall workings by only the thickness of
the 'bull quartz' vein, about 6 ft.
The footwall orebody worked by Melones Mining Company was
stoped for the following lengths: From 200-ft. level, 480 ft. long to
865-ft. level, where stope was 660 ft. long. On 1100-ft. level, 380 ft.
long and on 1350-ft. level, 290 ft. long. It shortened below there and
gave out at 2170 ft., where there was a stope 80 ft. long. The maximum
width of this vein was 65 ft. but the average stoped was 25 ft. to 30 ft.
wide. This orebody was what is commonly called a stringer lead, com-
posed of hydrothermally altered amphibolite schist, charged with pyrite
and traversed by numerous quartz stringers.
The hanging-wall vein (previously described under Morgan Mine)
was shorter in stope length and leaner in gold content after entering
MOTHER LODE GOLD BELT 135
Melones Mine and below the fault wliicli threw the lower part of vein
system eastward.
Carson Hill Gold Mines, Incorporated, took Melones property in
1920. They sank a new internal shaft from the 3000-ft. level, 225 ft.
south of the bottom of Melones shaft, on a 57° incline to 4600 ft.
(including 50-ft. sump). From this, levels were turned at 3275, 3375,
3500, 3620, 3750, 3875, 4000, 4125, 4250, 4375 and 4550 ft. For some
distance below the 3000 ft. level the hanging-wall vein was pinched.
From 3500 ft. downward it widened somewhat. On the 4125 ft. level,
it was stoped 150 ft. long and 19 ft. thick; on the 4375-ft. level, the
stope was 70 ft. long and 20 ft. wide in 1924. In that year, of a total
of 140,098 tons milled, about two-thirds came from the Morgan Mine
and one-third from Melones. Though the latter was somewhat higher
grade than the ore from the Morgan, neither the tonnage available nor
gold content were sufficient to encourage deeper work. Operation was
continued on the three mines (Morgan, Melones and Calaveras) until
December, 1926, the last named receiving most attention during the
final year.
Production of Melones Mine.
]\Ielones Mine was always known as a low-grade producer, and
during the operations of Melones Mining Company was worked prob-
ably at lower per-ton cost than anj^ other large lode mine in the State.
So far as. can be learned, the average recovery for an entire year only
once exceeded $2.70 a ton ; and during only a few years was it over $2
a ton. The total production was about $4,500,000 under Melones Min-
ing Company. There is no public record of dividends.
The mill, originally of 60 stamps, but increased to 100 stamps by
1905 and 120 in 1914 reached a maximum output of over 245,000 tons
in 1917. Stamps weighed 1050 lbs. each and dropped 7 inches 102
times a minute, crushing through 20-mesh screen, with oiitside amalga-
mation. For concentration, 20 Frue vanners and 27 Wilfley tables were
used, with reclassification and reconcentration of middlings. Concen-
trate was cyanided in a 20-ton plant. Later, the sand was cyanided
by percolation and slime was treated by counter-current decantation.
The total average recovery was 83 per cent to 85 per cent, with 92
per cent saved from the concentrate. The concentrate yielded from $25
to $44 a ton in gold and silver (the latter being present in very small
quantity) and formed from 2^ per cent to over 4 per cent of ore. The
operating cost was reported to be $1.60 a ton in 1913, but increased
during the war so that the company reported it was costing about $20
an ounce to produce gold.
Calaveras Coiisolirl-afed Mine (Calaveras, Santa Cruz, Ivanhoe,
Mexican, Extension, Relief, Stevens and Brown and other patented
claims, 17 in all), also a part of the present Carson Hill holdings, had
a separate history under previous owners. In the early 1890 's, an adit
1400 ft. long had been run northward from a point 50 ft. above the
river on the Calaveras claim. Later a shaft was sunk 600 ft. deep,
north of this and ore was milled with 20 stamps, but work stopped about
1895. Nothing more was done until about 1913. In April, 1917, the
Calaveras became a producer again under Carson Hill Gold Mining
Company, but after the discovery of the Morgan ore-shoot, and because
136
CALAVERAS COUNTY
of the lower grade of the Calaveras ore, attention was devoted prin-
cipall}'^ to the Morgan shoot and little further production was made
from the Calaveras until near the end of the operations. In 1926 a
large part of the production came from this mine. (See ante). The
production between 1917 and 1920 was 82,591 tons which averaged
almost exactly $3 a ton yield.
The Calaveras vein, often regarded as the main strand of the
Mother Lode, was developed in later years through an adit entering the
hill near Melones and following the lode nearly north for 2050 ft.
Ahead of this the vein outcrop was extensively prospected by trenching.
This main adit was called 1000-ft. level, all levels on this and adjoining
claims being referred to apex of the vein on the New Year claim on the
summit of Carson Hill. Trenching at intervals of 15 to 40 ft. when in
Open cut on Santa Cruz Claim of Calaveras Group of Carson Hill Gold Mines,
Inc., looking southerly.
Photo hy Walter W. Bradley, May 23, 1934.
ore was done from coordinate 850 north to coordinate 2350 north. The
trenching across the lode generality showed two strands but in places
three of low-grade ore separated by rock too low in gold content to
make ore. Over 1500 samples were taken from these trenches. The
width of the different strands that gave assays high enough to be of
interest varied from 6 to 20 ft.
From the 1000-ft. level the lode was extensively prospected bj
raises to the surface, crosscuts east and west, and a winze (at a point
950 ft. north of adit portal) from which levels were turned at 1123,
1250 and 1375 ft. in depth. The first two of these levels were each run
about 500 ft. north on the lode, but only a short distance south. Stopes
were worked above all of these levels, a length of 210 ft. on the 1250-ft.
MOTHER LODE GOLD BELT 137
level, 316 ft. on the 1123-ft. level and 370 ft. on the 1000-ft. level, hav-
ing been prospected in this way to a height of 40 ft. above each level.
A poor zone nearly 800 ft. long separated two ore shoots, each about
250 ft. long, on the 1000-ft. level. This work had been done before the
discovery of the Morgan ore-shoot, and we have no record of the work
done in 1926.
The vein averaged 15 ft. wide in parts of these workings but
generally about 7 ft. in width was classed as ore. It was in lenses and
stringers of quartz in the altered amphibolite schist. In the 1130 stope,
about 4 ft. of a total of 15 ft. was of stringer leads in the schist on the
hanging-wall side; the rest was quartz containing small lenses and
irregular bunches of schist. The sugary, crushed quartz showing a thin
casing of schist was the best part of vein ; the hard, glassy quartz con-
tained only 60 to 70 cents a ton in gold. The footwall was swelling and
hanging wall heavy and the workings were hard to hold open long, even
with heavy timbering.
The sulphide content of ore was 2 per cent and in 1918 it averaged
$68 a ton in gold. Ore was handled in a mill containing twenty 1250-lb.
stamps, 2 Hardinge mills, amalgamating plates and Deister concen-
trators.
Chaparral HUl Grovp includes seven patented claims and two
mill-sites three miles south of Angels Camp, the Bright Star claim of
this group joining the Relief claim of Carson Hill Mines on north.
There is one of the massive quartz outcrops forming the backbone
of the hill, and having a thickness of over 100 ft. in places. A series of
shallow shafts and several adits have been run on these claims. On
the Vanderbilt claim an adit was run 500 ft., mostly on the vein, and
on Chaparral Hill claim a crosscut diagonally across the formation was
464 ft. long, giving a depth of 300 ft. below the apex. About 1922,
Chaparral Hill Operating Company, a subsidiary of Carson Hill Gold
Mines, Incorporated, began work and did considerable prospecting on
these claims through the nearby Hardy shaft. No important ore
discoveries were reported as a result.
The vein prospected is one of the schist stringer leads on the hang-
ing-wall side of the massive 'bull quartz' vein. It had an average width
of 15 ft.
So far as known, no production has been made in late years from
these claims.
Colnnihia Mines Company prospected the Columhia claim 2| miles
south of Angels Camp in 1914-1916. A 2-compartment shaft was sunk
250 ft. on 62° incline. Levels were turned at 100 and 200 ft. and short
drifts were run. The above company installed a 5-stamp mill, com-
pressor and a gasoline hoist. A few hundred tons of ore was milled in
1914, but there has been no recent activity.
Commodore {Golden Gate) Mine is a mile north of San Andreas.
Under the latter name it was reported as being worked in 1870 through
an adit 450 ft. long. Apparently little more work was done until 1899,
when the shaft was sunk 300 ft., the first 80 ft. vertically and balance
on incline of 75° in the footwall. Crosscuts were run east to prospect
the 'Commodore vein.' and drifts were run several hundred feet north
on this on both the 200- and 300-ft. levels.
138 CALAVERAS COUNTY
The 'Commodore vein' is reported to be a mineralized quartz
diorite intrusive, with a crushed zone about 4 ft. wide on its hanging
wall side also carrying some gold. Both walls are serpentine.
In May, 1900, a mill-test of 200 tons from these workings was made,
with the announcement that if this averaged $4 a ton a 60-stamp mill
would be built. There has been no further record of activity until July,
1933, when the work of reopening was begun by Best & Belcher Min-
ing Company. A fire interrupted work in October, but progress has
been made since and early in 1934 the 200-ft. level was being prospected
by a crosscut.
Demarest Mine, though ^omewhat west of the line of the Mother
Lode if projected on a uniform strike north, may be considered here
because of its geologic associations. It is on Cherokee Creek in Sees.
9, 10, 15 and 16, T. 3 N., E,. 12 E., about six miles south of San Andreas,
on an agricultural patent.
It was first worked in the 1850 's. An elaborate scheme for treating
the sulphide by steam was a failure and it was 1898 before the prop-
erty became active again. The shaft was deepened from the 100-ft. level
at an angle of 60° in the footwall slates to 690 ft. and levels were run
at 100, 300, 400 and 600 ft. From 1898 to 1901, inclusive, ore was
stoped from the 400-ft. level to within 80 ft. of the surface. The total
production for these years is claimed to have been about $40,000 from
ore that averaged slightly over $8 a ton.
After 1901, the Demarest lay idle until 1924, since which year it
has been the subject of several promotions, including Bear Mountain
Development Company, Cherokee Development Companj-, and finally,
during 1934, Alaska B. C. Gold, Incorporated. The first two of these
did some underground work and milled less than 1000 tons of ore which
yielded about $9 a ton.
Three veins occur in a width of 350 ft. but all work has been on the
middle vein which lies at the contact of a strip of Mariposa slate about
150 ft. vride on the west, and one of the Calaveras formation some 200
ft. wide on the east. The average width of middle vein on the 600-ft.
level is said to be 6 to 10 ft., but this could not be verified as the lower
part of mine was under water at time of visit. The last work done by
Cherokee Development Company was the extension of the 100-ft. level
southward along the vein under Cherokee Creek, to a total length of
325 ft. Here the vein is reported to have widened from a few inches
to a good workable width in the last 25 ft., with encouraging assavs.
The 300-ft. level is 300 ft. long; 400-ft level 400 ft. long and 600-ft.
level 420 ft. long, all drifts having been run southward.
There are 20 stamps of which 10 have been erected in a wooden
building; rock breaker, electric motors, 3 Frue vanners, hoist, 10 by
12 in. air compressor and 6 by 8 in. triplex pump.
Fellowcraft Mine, one-fourth mile north of San Andreas in the
Calaveras slate is one of the old prospects on which no work has been
done in late years. It has a shaft reported to be 230 ft. deep on an
incline of 54°, with three levels, the deepest at 200 ft., from which the
first vein, reported to average 2 ft. wide, has been drifted 100 ft. each
way, north and south. Crosscuts were run east from the 100-ft. and
200-ft. levels to a zone of amphibolite schist and quartz reported 4 to
8 ft. wide, the crosscut on 200-ft. level being 135 ft. long. Some stoping
MOTHER LODE GOLD BELT 139
was done above 100-ft. level. The last production, less than $1,000, was
reported in 1907.
Finnigan Mine covers 2100 ft. on the Mother Lode on north side
of Carson Hill, adjoining Reserve and Enterprise claims of the former
Melones Mine.
The vein mined in the past is on the footwall of the 'bull quartz'
vein, and is the same ore mined by Melones Mining Company in their
glory hole adjoining the Finnigan. The orebody, consisting of a
stringer lead and mineralized amphibolite schist, has a maximum width
of 100 ft. in the glory hole. It has a hard greenstone footwall, and the
massive 'bull quartz' vein for hanging wall.
This mine is said to have been worked since 1872, but no record of
production previous to 1897 is at hand. Since that year, the total out-
put reported has been over $120,000. This has been partly obtained
from milling the low-grade ore, and partly from pockets. Milling ore
yielded from about $2 to $4 a ton. Mining from an open cut and tun-
nels gave low operating cost, estimated to have been as little as 90 cents
a ton before the war. The old open-cut workings were on an ore-shoot
about 200 ft. long by 70 ft. wide. The Hawkins tunnel was at a depth
of 465 ft. below the outcrop. The Talbot tunnel ran 400 ft. eastward
from the glory hole. The open-cuts of this and Melones Mine finally
formed one immense pit and a suit against the latter company for
trespass resulted.
The 10-stamp mill used before 1913 was replaced in 1920 by Lewis,
Gilman and Moore and a few thousand tons of ore was milled in 1921.
This yielded about $3 a ton in gold, one-half of it in concentrate, which
formed 3 per cent of ore. In June, 1923, the glory hole caved in and
it was reported the caA^e had crushed the Finnigan workings. Since
then the tonnage handled has been small but there has been some pro-
duction every year to and including 1931.
Ford Mine, at San Andreas, is another of those which have been
prospected quite extensively in recent years without fulfilling the
hopes of its operators. Geologicallj^, it is an extremely interesting
claim and this is undoubtedly the reason it has received generous
attention from previous writers. For the details of geology, the reader
is referred to past reports of the State Mining Bureau, particularly
Bulletin 18 ; and to Professional Paper 157 of the U. S. Geological
Survey.
The Ford has an inclined shaft 750 ft. deep with levels at 100,
200, 300, 400 and 700 ft. During the past 10 years it has been in
the hands of several companies and each has been active a short time.
The production record is meager. In 1895 and 1896 a small yield was
reported, and it was said at that time that in earlier years considerable
gold had been sluiced from the surface. Again, in 1899, a little over
$3,000 output was reported. In 1924 a few hundred tons of low-grade
was milled, and all the gold saved was contained in the concentrate,
which formed 3% of ore, and carried some copper and lead.
There are reported to be four veins on the property, but later
work has been devoted to two — the east and west veins. The main
vein, where the present shaft was sunk carries some telluride ore
and rich specimens have been taken from it on the 100-ft. level, at times
well sprinkled with free gold, but limited in quantity. This vein,
140 CALAVERAS COUNTY
according to Knopf is wide on the 300-ft. level, divided into stringer
leads of 30 and 25 ft. in width by 30 ft. of dolomitized amphibolite
schist. The country rock is amphibolite schist containing some layers
of black slate.
Gold Cliff Mine includes the Pilot Knob, Gold Cliff, Madison,
Fairfax, Excelsior and Peachey No. 1 and No. 2 claims, the last two
being placer claims. The group covers 5400 feet along the course of
what has commonly been called the main Mother Lode, because of
the occurrence of bold outcrops of quartz so commonly associated
with the main lode elsewhere. The distinction loses its significance
here because the best producers of the camp do not show these out-
crops and lie east of the Gold Cliff, the two branches being 3000 feet
apart on the surface but the veins meeting at a depth of 2700 feet.
The upper part of the Gold Cliff was worked by an open cut.
In these workings the hanging wall dips east at a steep angle and
generally shows the massive barren quartz vein, forming the imme-
diate hanging wall of the ore. The ore zone was over 100 feet wide
near the surface on the north end. The footwall converges toward
the hanging wall going south and in depth. The ore in this trough-
like bodj" was crushed amphibolite schist, traversed by nearly flat seams
of quartz which are from a few inches to three feet wide. The entire
mass in this crushed zone is said to have averaged $2 to $2.50 a ton, and
was cheaply mined and yielded a profit.
Later a shaft was sunk from the bottom of the open cut and the
mine and mill were operated until April, 1920. The orebody devel-
oped and worked in these later operations is a thick chimney of solid
white quartz and crushed mineralized wall-rock lying at the junc-
ture of two veins. The footwall is amphibolite schist, broken, highly
mineralized and not well defined. The hanging wall is smooth, hard
amphibolite schist, deeply grooved by movement. This firm and nearly
plane hanging wall was preserved in the deepest workings of the
Gold Cliff, and w^as one of the principal factors which permitted cheap
operation.
The ore-shoot varied in dip from 30° to 65°, averaging 45° N.,
to the 1600-ft. level. Between the 1600-ft. and 1700-ft. levels there
was a nearly horizontal fault, throwing ore several hundred feet north.
For 800 feet the vein is nearly flat. A drift was run north that
distance from the bottom of the 1700-ft. shaft and a winze had been
sunk from near the face to a depth of 270 feet late in 1919. The
ore-shoot on the 1700-ft level was comparatively short but was 25
feet thick. The white sugary quartz was said to be of no value, usually,
the gold being in the crushed schist, and 65 per cent of it in the fine
sulphides which formed as high as 10 per cent of ore. Coarse cubes of
pyrite, probably representing the primary pyrite of the original
igneous rock from which the schist was derived, are said to carry only
$5 a ton. The fine crystals of pyrite yielded a valuable product, as
the concentrate was worth from $50 to $80 a ton. The 1900-ft. level
was the lowest being stoped, but the Gold Cliff vein had previously
been prospected from the Utica workings at a depth of about 2700
feet from the collar of Utica (Cross) shaft, at the place where it
intersected the Utica vein. It had been hoped that ore would be found
at this intersection but results of the work were disappointing.
MOTHER LODE GOLD BELT 141
The Utica Mining Company operated a 40-stamp mill with 16
Frue vanners, and crushed 225 tons a day up to April, 1920, when
adverse economic conditions and falling off in working efficiency of
miners are said to have hastened closing. The owners report that the
total production was $2,834,000.
Great Western claim (not to be confused with others of same name
on East Belt) is at Altaville and contains about four acres. In Novem-
ber, 1896, a test run yielded well in gold. The shaft was then 70 ft.
deep and the fissure or vein reported 6 ft. wide. AVork was resumed
in April, 1897, and stopes were opened on the 50-ft. and 100-ft. levels.
That year over $10,000 production was reported. The shaft finally
reached a vertical depth of 220 ft. and the 200-ft. level was turned,
all levels running south. No further output was recorded after 1897.
Gvnn Mine was located in 1851, and an inclined shaft 200 feet
deep was sunk soon after. Some rich ore was found near the surface,
but most of the ore to a depth of 400 feet was reported low-grade.
About 1867, the mine passed into the control of Senator Gwin and
from then until the end of 1882 was worked as a family property
with only scanty records kept, and few of those available. In 1871,
the Alexander Mine on the north was purchased. The property covers
a length of 4989 feet along the lode. From the 400-ft. level to 900-ft.
level, the average of ore milled was better than above ; but no details
of this period of work are to be had. From 1867 to 1871, forty stamps
were in nearly steady operation. From April 7, 1871, to August 4,
1882, the total bullion output (including only one lot of concentrate,
$11,565) was $1,399,146, and a contemporary report^ said the mine
had produced over $2,000,000. In 1882, and for many years previous,
two mills with a total of 60 stamps, were operated. The stamps weighed
only 500 lb. each, dropped 75 times a minute and crushed an average
total of only 120 tons of ore a daj'. The ore evidently ranged in average
value from $3 to $7 a ton in free gold and the best of it appears to have
come from depths of 1300 to 1400 feet, where the vein reached a thick-
ness of 20 to 30 feet. The average jueld in 1882 was reported at $6
a ton and cost of mining and milling $3 a ton. On the 1400-ft. level
the ore was drifted on for 1040 feet, and the south shaft had reached
a depth of 1530 feet, before the mine was closed in 1882. The shaft
was crooked and the mill and other equipment worn out; money was
needed and gold mining at the time was in a slump.
The mine lay idle until 1894, when reopening began under Gwin
Mine Development Company. In two years the shaft was sunk 1000
feet. By January, 1897, work had reached a depth of 1400 feet and
the new 40-stamp mill was started. The following is a partial record
of the results of this period of operation: Januarv, 1897, to April 1,
1900—171,748 tons vielded $702,003.81; April 1,' 1900, to April 1,
1901—99,211 tons vielded $419,421.48; dividends 1897-November 30,
1901, $266,000.
Soon after, the mill was enlarged to 100 stamps with 24 Fruo
vanners. In the year ended March 31, 1903, when 138,383 tons of
ore was milled, the cost per ton for mining and development was
$1.9443; for milling and concentrating $0,306 and for hauling, freight
iCal. state. Min. Bur. R. VI, pt. 2, pp. 30-34.
142 CALAVERAS COUNTY
and smelting charges on sulphide concentrate $0.1588 per ton of ore,
a total of $2.4091 a ton. Wages at the time averaged $2.50 an 8-hour
shift. Among the conditions responsible for low costs were the size
of vein and length of orebody, and the utilization of water twice for
power. After using about 200 miner's inches daily, purchased at
15 cents an inch for 24 hours, for running the hoist and mill, it was
dropped down the canyon a vertical distance of 380 feet and used to
compress air.
The mine was finally worked to a depth of 2850 feet, the last shaft
having been sunk 2400 feet vertically with a winze 450 feet deeper,
which was sunk from the 2400-ft. level at a point 450 feet south of
main shaft. This deepest work is said to have revealed ore-shoots of
a combined length of 450 feet and "hundreds of feet" of lower grade.
The main ore-shoot above this had been as much as 1400 feet long.
The property has been closed since 1908, and as no state reports
were published on the Mother Lode mines from 1900 until 1914, the
following notes are taken from Report XIII of the State Mineralogist,
written in 1896 when the shaft had reached 1335 feet.
"A vertical shaft was started in the hanging-wall slate 485 feet from the
vein » * * on May 1, 189 4. * * * The 8' hy 15' shaft is 5' by 12' in
the clear, divided into three compartments and timbered from top to bottom
with 12" by 12" Oregon pine. * * * A station was cut at the 300' level and
a tank of 4000 gallons capacity constructed under the floor for the purpose of
taking up surface drainage. At the 700' level a station was cut and a reservoir
of 12,000 gallons capacity constructed. * * * At the 1000' level a crosscut
was run 69' west through the vein, 15' 6" wide horizontal measurement, the
footwall being 58' W. of the shaft. A drift was run 125' on this level, the
vein being found to be 15' wide; the material is somewhat mixed, but con-
taining some good ore. At 1195' the shaft reached the hanging wall of the
vein, which at that point has a gouge 1' thick. At 1245', the footwall, hard
black slate, was cut. * • * The development of the mine shows the strike
to be N. and S. and the dip 77° E., and that the vein conforms very nearly
in both strike and dip with the enclosing black slates. A dike of igneous rock
is occasionally found accompanying the vein. It is light gray, fine grained,
and appears to be a type of diabase."
Hardy Mine, comprising the Hardy and McCreigh and Reed
claims, 9.05 acres in all, belonging to Hayward and Hobart Estates
et al; lies on the north slope of Chaparral Hill three miles south of
Angels Camp. In years past it produced a number of pockets from a
large white quartz vein. From 1914 when 59 tons was crushed, until
1922, there is no record of work. In 1922 and 1928 the claims were
prospected by Chaparral Hill Operating Company, a subsidiary of
Carson Hill Gold Mines, Incorporated. It had formerly been worked
through an adit 360 ft. long and a winze giving a depth of 300 ft. on
dip. The old shaft, 170 ft. deep, was used as an entry for the later
work. A small production was reported in 1923, since when no further
work has been done.
Jolly Tar Mining Company was a promotion based on a lease and
option to purchase Jolly Tar Q. M., a patented claim one-half mile
north of Altaville on the Esmeralda Road.
Between 1920 and 1924 an inclined shaft was sunk about 300 ft..
with short levels at 150 and 280 ft. The country rock is blocky, amphi-
bolite schist with meager seams of calcite and quartz. The dump indi-
cates that all the work was done in rock of this kind. No ore was found.
The last activity so far as known was in October, 1926.
MOTHER LODE GOLD BELT 143
Kirhy Development Corporaiion owns the Baehman Mine and the
Wells property and have an option to buy the Thorpe Mine, all near
Fourth Crossing on the Mother Lode highway.
Baehman Mine was prospected under option by California Explora-
tion Company for some time after 1894, but evidently without
important results. Work was started again in 1921 when some 40 tons
of ore was crushed and paid well. The present company took it about
that time. A new shaft was started 65 ft. southeast of the old 70-ft.
one and was sunk 305 ft. on an angle of 75° with levels at 110 and 285
ft. The work on the 110-ft. level consisted of drifting and crosscuts
on a quartz vein between a greenstone footwall and hanging wall of
interbedded slate and schist. The south drift was about 70 ft. long;
on north some 300 ft. of work was done, exploring a length of 130 ft. on
the strike and a wadth of 60 ft. Assays were generally low on this level.
On 285-ft. level, a drift was run 160 ft. west and northwest largely in
a fault, and about 135 ft. southeast. Good assays w^ere reported near
the face of southeast drift, and at shaft. About 20 ft. north of shaft,
a fault striking west is reported to cross vein and throw it north and
west; another segment of vein 45 ft. long was later found on north
between this fault and a second minor one. The sections of vein
sampled ranged from 1 ft. to 5-| ft. wide; several other veins run from
the Thorpe into the Baehman.
Thorpe Mine was worked by Thorpe in a small way before 1894.
It is located on several small veins, showing on the surface material
which carried some gold for a width of 50 ft. of mixed amphibolite
schist, quartz and slate. Thorpe Mining Company began work about
1894 and produced a few thousand dollars in 1895, sinking the shaft
to 637 ft. on angle of 73°. California Exploration Company erected a
30-stamp mill in 1898 and enlarged part of the shaft. They quit soon
after, wdth no record of production. Nothing more was done until
1927 w'hen the present company cleared and repaired the shaft and
spent considerable time and money in reopening and sampling the
workings, and doing some new work.
According to Alfred G. Kirby, ore was found "mostly where the
margins of the main fissures are cut by zones of oblique minor fissuring.
Usually only marginal parts of main fissures are ore-bearing, the central
parts being too low grade to mine unless a cross-fissure causes enrich-
ment." The veins are mostly in schist, and strike N. 60° W., with a dip
of 53° NE., flatter than the dip of the schistosity of the schist. Accord-
ing to an old map, stopes had been worked to a height of 70 ft. above
the 300-ft. level and from 30 to 40 ft. above the 400- and 500-ft. levels
before July, 1899. Though most assays on the 500- and 600-ft. levels
are low, there are several short sections showing fair values, notably
one behind the shaft on 600 north drift where the wudth sampled varied
from 14 inches to 5| ft., and one on the 600 south drift.
The equipment on the Thorpe includes thirty 1000-lb. stamps,
100-h.p. double drum hoist, capacity 2000 ft. deep, compressor, electric
motors and pumps. No work has been done since 1930. There is
another old shaft on the Thorpe about which information is lacking.
Lightner Mine at Angels Camp, between the Utica and Angels
Mines covers only 420 ft. on the Mother Lode. It was first opened and
144 CALAVERAS COUNTY
equipped with a 10-stamp mill about 1860, but the material milled from
an open cut to a depth of 70 ft. did not repay the cost of operation.
Production was resumed, at first from surface ore, in 1896. From then
until 1910 it was in steady operation and a producer annually; and
after an interruption in 1910 due to the caving of the old shaft, was
productive until 1915, since which time there has been no underground
work.
The Lightner produced between 1896 and 1915 over $2,500,000.
Lightner Gold Mining Company was incorporated in 1896 with a capital
of $125,000 in $1 shares, of which 62,287 shares were issued. Dividends
amounting to $550,000 are reported, and when the property was closed
the management claimed the' mine still contained 200,000 tons of ore
above the 300-ft. level.
Geologically, the deposit is the same as those in the Angels and
Utica mines. The main vein was reported 120 ft. wide between the
4th and 6tli levels but split into three strands on the 6th level, 100 ft.
north of the shaft. The 'talc' or 'bull-quartz' vein cut across the
main vein between the 500- and 600-ft. levels. The ore vein is claimed
to have been picked up below the 'talc vein' in a crosscut run 150
ft. on the 900-ft. level, but its dip had steepened to 80° E. The walls
of the vein are hard, but the country considerably broken by movements
caused by the removal of large orebodies in this and the adjoining
mines, so heavy square-set timbering had to be employed.
After the old shaft had caved in 1910 a new one was sunk 255 ft.
from it and levels were turned at 100-ft. intervals to a depth of 600 ft.
This shaft was finally sunk to 1050 ft.
The drainage problem would have to be considered carefully in
connection with any plan to reopen and deepen this or Angels Mine,
due to the great amount of ground opened in past years in the adjoining
mines now standing idle.
Madison Mine, adjoining the Gold Cliff on the south and also
belonging to Utica Mining Company, is similar geologically to the Gold
Cliff. It was opened many years ago by an inclined shaft 1500 feet
deep with levels 100 ft. apart, the longest connecting with the Gold
Cliff. Other long drifts were run south. These drifts which were run
for prospecting purposes with the intention of opening a large low-
grade producer, were from 6 to 20 ft. wide and 10 to 20 ft. high and
the rock from thousands of feet of such work is said to have paid when
milled. The material was so low-grade, however, that it was decided
that it would not pay for extensive stoping, considering the expense
that would have been incurred for the lieavj^ square-set timbering or
filling that would have been needed to support large openings.
The auriferous rock was the chloritic amphibolite schist similar to
that in the Gold Cliff, lying on the footwall side of a massive quartz
vein from four to 60 feet thick, which was found to be low-grade in
gold content everywhere in the mine. The auriferous schist was from
five to 20 ft. wide with 4 per cent auriferous sulphides, and was in
places in contact with the massive quartz vein, but elsewhere separated
from it. The big quartz vein was crushed in places and carried a heavy
gouge on its hanging wall.
A 40-stamp mill was operated at intervals on this mine, which has
not been active since about 1888.
,ty UJ
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CLAIM MAP
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MOTHER LODE
CALAVERAS CO., CALIFORNIA
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ACCOMPANYING BULLETIN 108, BY C.A.LOGAN.
MOTHER LODE GOLD BELT 145
^ Maltman Mine is another of the small ones between Angels Camp
and Altaville, northeast of Angels Mine. It was worked to a depth
of 75 ft. before 1900, and had a 4-stamp mill. By 1903, the shaft had
been sunk to the 200-ft. level and in that year the last production of
record was made, reported as averaging $5 a ton.
Melones Mine (See under Carson Hill Mine).
Mohawk Mine is two miles from Angels Camp on the Copper-
opolis road. It has a shaft 200 ft. deep, from which a crosscut 300
ft. northwestward on the 100-ft. level cut a black slate gouge with
3 ft. of broken quartz 50 ft. from the shaft; then 100 ft. of black
slate or schist, followed by hard green schist. 'High grade' was
found in small quantity 200 ft. from the shaft and 4 or 5 tons yielded
$600. In all, the claim has produced about $8,000, mostly from
shallow holes 20 to 50 ft. deep. There is a 2-stamp mill, small hoist
and pump and electric power. Last work was done in 1924.
Morgan Mine (See under Carson Hill Mine).
Narth Star Mine, including North Star, Albany, New Discovery
and other claims and mineral rights, is on a short westerly branch
of the Mother Lode southeast of the Gold Cliff Mine. The deposit
worked was in the characteristic altered and mineralized amphibolite
schist of the district. The strike is nearly west and dip north. No
record of the early history is available.
It was reopened about 1909 by Dolling Gold Mining Company
who sank the shaft 480 ft. on 60° incline, opened levels 100 ft.
apart and ran drifts reported to range from 60 ft. long on 400-ft.
level to 300 ft. on 100-ft. level. A 40-stamp mill was erected and
production was reported from 1911 to 1913 inclusive. The material
milled was mostly low grade. An average width of 15 ft. was worked
and ore was reported broken and scattered by faulting. The total
production for the above period was less than $90,000. A large part of
the gold was in the sulphide Avhich formed lh% to 2^i of rock milled
and as.sayed about $50 a ton.
Oriole Mine (also called Harris or Big Bonanza) a mile west
of Angels Camp produced gold reported to have amounted to over
$30,000 from pockets near the surface. In 1897, the Oriole Mining
and Milling Company took out about $8,000 from a shallow shaft.
A shaft in July, 1898, had reached a depth of 175 ft. In October,
1898, at a depth of 200 ft., the vein Avas reported 10 ft. wide. At
300 ft. depth, it was stated the vein was 50 ft. wide and on 400-ft.
level was reported 30 ft. wide. The shaft finally reached a depth
of 850 ft. while the Gould Mining Company was working there, with
the first level reported at 130 ft. and others from 200 ft. down at
]00-ft. intervals except at 700 ft.
This is another of the small mines of wiiieli we liave only a frag-
mentary record. It made some production in 1903 under the latter
company and this appears to be the last of record. The vein had been
explored for 500 ft. south and 400 ft. north on the 500-ft. level, accord-
ing to a statement published in 1903, but the State kept no records at
the time and the full extent of work is unknown. A 10-stamp mill was
10—4156
J
MOTHER LODE GOLD BELT 145
Maltman Mine is another of the small ones between Angels Camp
and Altaville, northeast of Angels Mine. It was worked to a depth
of 75 ft. before 1900, and had a 4-stamp mill. By 1903, the shaft had
been sunk to the 200-ft. level and in that year the last production of
record was made, reported as averaging $5 a ton.
Melones Mine (See under Carson Hill Mine).
MohaivJc Mine is two miles from Angels Camp on the Copper-
opolis road. It has a shaft 200 ft. deep, from which a crosscut 300
ft. northwestward on the 100-ft. level cut a black slate gouge with
3 ft. of broken quartz 50 ft. from the shaft; then 100 ft. of black
slate or schist, followed by hard green schist. 'High grade' was
found in small quantity 200 ft. from the shaft and 4 or 5 tons yielded
$600. In all, the claim has produced about $8,000, mostly from
shallow holes 20 to 50 ft. deep. There is a 2-stamp mill, small hoist
and pump and electric power. Last work was done in 1924.
Morgan Mine (See under Carson Hill Mine).
North Star Mine, including North Star, Albany, New Discovery
and other claims and mineral rights, is on a short westerly branch
of the Mother Lode southeast of the Gold Cliff Mine. The deposit
worked was in the characteristic altered and mineralized amphibolite
schist of the district. The strike is nearly west and dip north. No
record of the early history is available.
It was reopened about 1909 by Dolling Gold Mining Company
who sank the shaft 480 ft. on 60° incline, opened levels 100 ft.
apart and ran drifts reported to range from 60 ft. long on 400-ft.
level to 300 ft. on 100-ft. level. A 40-stamp mill was erected and
production was reported from 1911 to 1913 inclusive. The material
milled was mostly low grade. An average width of 15 ft. was worked
and ore was reported broken and scattered by faulting. The total
production for the above period was less than $90,000. A large part of
the gold was in the sulphide whicli formed 11% to 2^r of rock milled
and assayed about $50 a ton.
Oriole Mine (also called Harris or Big Bonanza) a mile west
of Angels Camp produced gold reported to have amounted to over
$30,000 from pockets near the surface. In 1897, the Oriole Mining
and Milling Company took out about $8,000 from a shallow shaft.
A shaft in July, 1898, had reached a depth of 175 ft. In October,
1898, at a depth of 200 ft., the vein Avas reported 10 ft. wide. At
300 ft. depth, it was stated the vein was 50 ft. wide and on 400-ft.
level was reported 30 ft. wide. The shaft finally reached a depth
of 850 ft. while the Gould Mining Company was working there, with
the first level reported at 130 ft. and others from 200 ft. down at
100-ft. intervals except at 700 ft.
This is another of the small mines of wliicli we have only a frag-
mentary' record. It made some ]n'oduction in 1903 under the latter
company and this apjoears to be the last of record. The vein had been
explored for 500 ft. south and 400 ft. north on the 500-ft. level, accord-
ing to a statement published in 1903, but the State kept no records at
the time and the full extent of w'ork is unknown. A 10-stamp mill was
10—4156
146 CALAVERAS COUNTY
operated that year and stoping is believed to have been done as deep as
the 600-ft. level.
Osborne Prospect is 3^ miles west of Angels Camp in Sec. 30,
T. 3 N., R. 13 E., on one o£ the mineralized zones characteristic of
the amphibolite schist in that region. In earlj^ days this ground was
worked superficially but no record remains of the output. The deep-
est old work was a shaft 101 ft. deep. In 1929 and 1930 Belmont
Osborne Mining Company put down a new shaft which was 150
ft. deep when visited in January, 1930. The two shafts are 330 ft.
apart and at that time a drift had been run 220 ft. southeast from
the old toward the new shaft. This shows stringer lead material
in sections from 9 to 15 ft. in length alternating with mineralized
schist along the course of the drift. The face at the time revealed a
width of 5 ft. in which there were two systems of quartz and calcite
stringers — one system nearly parallel and the other about perpendicu-
lar to the strike of schistosity, which is a little nearer north than the
course of drift.
A second-hand 20-stamp mill was erected and a small tonnage of
rock was milled in 1930, since when there is no record of activity.
Pioneer Chief Mine is Lot 37 in Sec. 29, T. 4 N., R. 12 E., about
two miles south of San Andreas. Other adjoining lands under agri-
cultural patent belong to the same owners. No record remains of the
early operation. Two shafts were sunk, one 125 ft. and the other 300
ft. and work had ceased by 1884. Fairbanks described it as "remark-
able for having a gouge of forty feet on the hanging wall. ' ' He classi-
fied the footwall as a dike of chloritic felsite and the hanging waU as
serpentine.
This claim has been unwatered and the workings have been
extended laterally and in depth at least twice in recent years. The
results of this work have been disappointing. Early in 1931, the
deeper shaft (535 ft. long, or 415 ft. deep vertically) was unwatered.
At that time, the 200-ft. level was 125 ft. long; 350-ft. level was 230
ft. long and 500-ft. level had been run 60 ft. Some further drifting was
done on the 260-ft. level that year. The results of sampling did not
substantiate claims made by the promoter and work stopped in a few
months. The only record of production in late years was in 1928.
when a small sum was realized from material yielding less than $2
a ton.
QuaJcer City Mine, Lot 44 in Sec. 26 T. 5 N., R. 11 E., four miles
southwest of Mokelumne Hill is in the section where the Mother Lode
Assuring I'e-enters the slate after having been in the greenstone for
several miles. This claim was located about 1868 and opened in 1887
but was worked for only a short time.
The walls are black slate, but the slate on footwall side is said to be
from only 6 inches to 5 ft. thick with a lens of greenstone next to it
on that side. There is a heavy black slate gouge, said to be 30 ft. thick
in the old workings, on the hanging wall of vein. The width of vein
was said to vary from a few inches to 4 ft. and there is a gouge
4 to 12 inches thick on the footwall.
The claim was opened by a drain tunnel 640 ft. long connecting
with a vertical shaft at a depth of 103 ft. The shaft was 108 ft. deep
MOTHER LODE GOLD BELT 147
in 1888, after which year no definite details are at hand. A Hunting-
ton mill was built, but there is no record of the production or gold
content of ore.
Rathgeh Mine is three miles southeast of San Andreas, adjoin-
ing the Union Mine on the northeast. It had a 5-stamp mill in 1870,
when the earliest production, amounting to $5,000, was recorded. By-
July 1, 1873, the shaft had reached a depth of 70 ft. and 150 ft. of
drifting had been done, with 600 tons of ore on the dump which the
owner reported was worth $7 a ton, containing 5% sulphides and
coming from a vein averaging 4 ft. in thickness. During the next
year 300 tons was crushed, probably of the above ore. The mill mean-
while was increased to 10 stamps. The shaft finally reached a depth
of 220 feet, with short drifts on the 120-ft. and 200-ft. levels.
T. A. Rickard^ has given an excellent account of the conditions
under which a large pocket was taken from this mine in 1887 and
excerpts are given.
"These pockets appear to be confined to the zone between the surface
and the water-level and to be dependent upon the results produced by the
small cross-veins which encounter the main lodes. In 1887 I had the pleasure
of extracting, in two hours, a little over 170 ounces of gold, worth about
$3,000, from one of these pockets. It was at the Rathgeb Mine, near San
Andreas in Calaveras County. The main lode consisted of 5 to 8 feet of mas-
sive "hungry-looking" quartz, the foot-wall of which was a beautiful augite-
schist and the hanging-wall a hard diabase. The water-level was 160 feet
below the surface. Down to this point, the country was oxidized, the hanging-
wall exhibiting only slight alteration, while the schist of the foot-wall was
softened and decomposed almost to a clay. This was traversed by numerous
small veins, which appeared to act as "feeders," forming bunches of rich ore
where they encountered the main lode. At the 120-foot level, south from the
shaft, there were some old workings ; and the examination of these led to the
discovery of a small seam, about one-sixteenth of an inch thick, filled with red
clay which carried a good deal of native gold. * * * It varied in thick-
ness and occasionally opened out into small lenticular cavities, containing a
clay in which the gold was distributed like the raisins in a pudding. Each of
these "pockets" yielded several hundred dollars worth of gold. At length the
streak widened to 6 or 8 inches of quartz, lined with clay. The amount of
red clay commenced to increase ; coarse gold became more frequent ; and a
big discovery was hourly expected. It was finally made. The vein suddenly
became faulted, and at the place of faulting, there was a soft, spongy, wiry
mass of gold and clay — more gold than clay * * * iWithin the next two
hours this pocket gave us $3,000, and during the following week it yielded
over $20,000, an amount which was obtained at a total cost of less than $200.
* • * The vein, AC, had been faulted about its own width, namely, 10
inches, by a small cross-seam, DE, and at this intersection, B, the pocket lay.
The gold was spong>' and was intermixed with quartz. The clay which pene-
trated the whole mass was partly red and ocherous, and partly a gray gela-
tinous material. In the quartz, and associated with the gold, there were
acicular black crystals of pitch-blende (uraninite) together with uranium
ochre. This association of gold with uranium is uncommon."
Incidentally, it may be said that this appears to be the only
reported occurrence of pitchblende in the State.
Shotgun Mine joins the Demarest holdings on the south. There
are several shallow shafts, the deepest 125 ft. long, on the footwall
vein, composed of quartz and slate ribbon rock and dike rock. This
claim has produced some high grade ore, and a small crushing of low-
grade ore was made in 1930.
In 1931 there was a hoist operated by a 12-h.p. gasoline engine,
{ind a 10 by 12-in. compressor with a 4-cylinder gasoline engine housed
in a corrugated iron building.
Sultana (first called the Winters or Marshall and later Bovee
Mine) includes Bovee and Fritz claims, Bovee mill-site and Fritz Pur-
1 The Formation of Bonanzas in Gold-Veins. Trans. A. I. M. E. 1901.
148 CALAVERAS COUNTY
chase, lying on both sides of the main street adjoining Angels Mine on
the north, at Altaville.
Winters Brothers found it in 1852 and worked by open cut, sort-
ing the rock and crushing the best in an arrastre. They were locally
reported as having obtained as high as $2,000 to $3,000 a ton, and were
supposed to have produced about $200,000 before selling to Wm. Bovee.
In the 1860 's a 10-stamp mill and much other equipment was operated
and the mine was opened to a depth of 300 ft. It was said the ore
yielded from $6 to $26 a ton. The mill was burned down about 1870,
but by 1884 a new one had been built and the property was being
worked by Captain Gushing, "with fair results," but no details of this
work are to be had. In 1899, Bultana Mining Company was formed
and worked until 1905. They produced some ore that yielded over
$6 a ton but most of the tonnage handled was low-grade. Their work-
ings reached a depth of 700 ft. All ore from the 300-ft. level to surface
has been stoped but it is said little was taken out below 300 ft. deep.
The next and lowest level was at 700 ft. where the west vein was drifted
150 ft. and east vein 75 ft.
This property contains the Mother Lode veins. Near the surface
four veins were mentioned as occurring in a width of 200 ft., with a
'main vein' of white, barren quartz. In the later workings only two,
called East and West veins, were distinguished. They are separated by
a layer of soft schist and lie between hard schist outer walls. They are
essentially stringer leads, and are reported 5 ft. and 14 ft. in average
width, respectively.
Thome {Illinois) Mine is the next one north of the Demarest in
the group lying on the west of the greenstone. It is the southermost
of several claims, having a dike of serpentine on the hanging-wall side.
It was worked principally during the period 1896-1900, when the State
published only one short report on gold mines. A 5-stamp mill (later
increased to 10 stamps) was put in operation in December, 1898, but
nothing is known of the output. The footwall is slate and immediate
hanging wall is schist. Two veins occur, one of 'ribbon rock' at the
contact, and one of 'gray ore' in the schist. They converge going
north.
The shaft was 200 ft. deep with two levels in 1900. There is no
later record, but the shaft is said to have been sunk deeper.
Tollgate Prospect (Port Arthur, Mar.shall, Beaker and Prince agri-
cultural patents), half a mile southwest of Altaville on the Copper-
opolis road, has an inclined shaft 150 ft. deep Avith levels at 100 and
150 ft. Less than 100 tons milled is reported to have assayed well and
to have yielded about $4 a ton in free gold, with an unknown amount
in the .sulphides. This came from the 100-ft. level, but about 50 ft. of
work on the 150-ft. level is said to have given assays too low to make
ore. There is a 3-stamp mill, 1 vanner, small hoist and buildings on
the property, which has not been worked for nearly 10 years.
Triple Lode Mine {Blair Consolidated and El Dorado, the latter
a consolidation of El Dorado, Emeline and Jumper claims). It is 1^
miles southwest of Altaville and contains 53.6 acres, patented.
The Blair Consolidated made some production from ground sluic-
ing in the .1880 's. In 1893 a mill was operated and two small stopes
about 20 ft. bv 30 ft. were worked from the 150-ft. and 200-ft. levels
MOTHER LODE GOLD BELT 149
in the old shaft. The ore was low-grade. No further record of activity
appears after 1898 until 1920 when Triple Lode Gold Mines, Incorpo-
rated, was formed.
The old shaft had been sunk 450 ft. with the above levels and one
at 400 ft. This work was done on the west vein. A new shaft was sunk
in the footwall about 700 ft. from the old one, to prospect other veins,
and it finally reached a depth of 560 ft. Levels were turned at 150,
250 and 500 ft. and it is stated about 3000 ft. of drifts and crosscuts
were run, of which 1500 ft. was on the 250-ft. level, where the middle
vein is said to have been followed 200 ft. and the east vein is reported
to have been crosscut about 200 ft. north of the .shaft. On the 500-ft.
level, all three veins are reported to have been cut. The hoist was not
running when the writer visited the place and the workings could not
be examined. The work was done in a northerly direction, away from
the old shaft.
The company fell into financial difficulties in 1924 on account of
labor liens, and a second-hand mill of 20 stamps which had been pur-
chased was not erected. J. Gianera, 670 Greenwich Street, San Fran-
cisco, has numerous assays of samples from the later workings. The
new shaft has a double-drum hoist, compressor, etc., but the old one is
not equipped.
This is another of the group of claims in the amphibolite schist
west of the main course of the Mother Lode.
Tulloch Mine, 2i miles south of Angels Camp on an easterly branch
of the Mother Lode, has been prospected at intervals over a long period.
The production has come principally from small tonnages crushed at
irregular intervals, and from pockets.
About 1917 the Lane interests deepened the shaft to 800 ft. and
milled a small lot of ore. Again in 1921, W. A. Bisbee did some mill-
ing for the owners. 1\\ 1922, Chaparral Hill Operating Company
unwatered the shaft for examination. The owners continued work on
a small scale thereafter for several 3'ears. Since 1926 it has been in
the hands of different promoters for short periods but they accomplished
little new work. There was a little production in 1928 and 1929 from
pockets.
Utica Mine comprises the Utiea, Stickles, Raspberry, Brown, Wash-
ington, Dead Horse, Jackson, Confidence and Little Nugget, covering
6135 feet along the lode. The Utica, 300 feet wide and 634 feet long,
and the Stickles, 300 feet by 600 feet, were worked before 1884 as
separate mines. Their history had not been particularly interesting
before that, and several failures had been made in attempting to work
them, but they became part of the most important and most profitable
group in the county and under the Utica [Mining Company were
operated until December 25, 1915, when the crew of 100 men then
employed were paid off and the operations ceased. The fifteen years
from 1890 to 1905 was the most important period in the company's
history. As many as 500 men were employed at one time and the
mines are said to have made a record in one month of $200,000 net pro-
duction, exceeding the nearest competitor, Stratton's Independence, by
$10,000. The gross output in the month of [May, 1895, is reported to
have greatly exceeded the previous record of $600,000 made by the
Standard mine at Bodie in July, 1878. Many stories ascribe to these
150 CALAVERAS COUNTY
mines a greater production than they actually made, as is usually the
ease where no figures are given out. However, during litigation Hay-
ward, a one-third owner of the Utica, had to qualify as a bondsman
and was required to show in court that he was worth $1,000,000. He
produced a record of the operation of the Utica and Stickles properties
from January, 1893, to September, 1895, showing that the gross pro-
duction during that period, which included an idleness of two to three
months, was $4,154,026.52. The expense was $1,683,414.24 and the net
income was $2,470,612.28. The total production of the Utica and
Stickles mines, according to figures furnished by the company, was
$13,635,000. The net profit is hard to arrive at, because the three
partners, Hayward, Hobart and Lane, spent very large sums in pros-
pecting and developing mines throughout the length of the California
gold belt and this money came in part from the profits of the mines at
Angels Camp. They also spent a great deal on the development of the
hydroelectric plant which still serves that region.
From a contemporary description of the ore occurrence by Lind-
gren, the following is quoted:
"The ore body of the Utica mine is in the form of a stringer lead, con-
sisting usually of numerous lenticular stringers lying nearly in the planes of
schistosity of the amphibolite schist, and separated by various thickness of
fissured and veined country rock. The stringers are largely quartz but car-
bonates are also abundant, especially in the smaller fissures. The wall rock
near the stringers is impregnated with pyrite, but the gold is said to occur
chiefly within the quartz of the veins. The stringers dip easterly, as a rule,
but are nearly vertical. Some rich specimens were seen in which the gold was
embedded in a gangue of calcite. Pyrite was the only sulphide noted in the
ore. Unfortunately, the attitude of those having the mine in charge was such
that no satisfactory scientific examination of it could be made in 1897.
"The Stickles mine adjoins the Utica. on the south and is under the same
management. As in that mine, the country rock is amphibolite-schist, but
it is in general more sheared and fissile than in the Utica. The ore body is
a complex network of small stringers inclosing more or less impregnated coun-
try rock. True walls are lacking, and stringers occur in the country rock
many feet away from the auriferous lead. The greater number of stringers
follow approximately the planes of schistosity, but others traverse the schist
in all directions. The ore body is separated into two longitudinal portions or
leads, by a horse of barren schist (and stringers) 30 to 50 feet in width. The
westerly lead is the more important, being from 60 to 90 feet wide, while the
eastern lead is only 20 or 30 feet. The leads and the horse, however, are very
irregular.
"The filling of the fissures is sometimes quartz, sometimes carbonates,
and sometimes a mixture of both. Pyrite and a little chalcopyrite were the
only sulphides noted, the former being usually finely disseminated in small
crystals through the vein material, and particularly through the impregnated
schist between the stringers. The richest ore is said to be the so-called
'brown quartz' which is a fine granular aggregate of quartz, dolomite and
sometimes albite, thickly speckled with small crystals of pyrite. This 'brown
quartz' does not always form well-defined veins or stringers, but is very
intimately associated with the country rock, and is in part an altered form
of the latter. The other vein minerals are free gold, sericite and a little
chalcopyrite. Gold is not visible in most of the ore, but occurs in considerable
masses in certain rich streaks."
In Report XII of the State Mineralogist the method of operating
underground and the character of orebodies being worked in 1893 at a
depth of about 1000 ft. are described. Stopes then were from 10 ft. to
over 100 ft. wide. The report states that
"In these broad portions are found ribs or masses of rock containing
little or no gold. The entire gold bearing zone, as it must be called in con-
tradistinction to a simple vein, consists of a great mass of altered diabase,
which by shearing and pressure has been rendered splintery or slaty and
subsequently altered to chloritic and ta'cose schists, with the infiltration of
much silica into the magnesian rocks and the replacement of large masses of
crushed diabase by solid massive quartz. Both the quartz lenses, bunches,
and veins and the magnesian schists, contain gold and auriferous pyrites."
Square sets of heavy round timber were used varying in diameter
usually from 18 to 30 inches. Timbering then cost 30 cents a ton of
MOTHER LODE GOLD BELT 151
ore. Drifts and other workings were large and all waste rock was
used in filling stopes. Later, when in lower-grade ore in the deeper
workings, the pillar system was used to save timber. The Cross shaft
finally reached a depth of 1470 feet. About 1100 feet north of it on
the l'400-ft. level a winze was sunk 1650 feet, and from the 1500-ft.
level of these workings a crosscut was run to the Gold Cliff. The
Stickles shaft was 1000 feet deep, with a winze from the 1000-ft. level.
The grade of ore in the mine varied greatly and at times rich
'pockets' were encountered in the Utica as well as in the other mines
of the district. Mill-head values were never revealed during the earlier
operations but probably went as high as $15 a ton at times. ^ There
were 120 stamps with a capacity of four tons per stamp daily in com-
mission in 1895 at the Utica and Stickles. The bulk of production came
from above the 1300-ft. level. At about that depth in the Cross shaft,
and at shallower depths to the north, a fault, filled by a talc zone 15
feet wide with a dip south and east, traversed the mines of the district
and although confirmatory details are lacking it appears that this was
the limit of the good ore. In the later operations the ore from the Utica
averaged $3.60 or less per ton. The working cost in 1913 was $2.15 a
ton. At that time 155 men were employed and most of them were paid
$2.50 to $3 a shift. Timber cost $2.30 per stick, and lumber $18 a
thousand feet. Sixty stamps were operated and gave a daily capacity
of about 300 tons, indicating an output of nearly two tons per man
daily. A big item in favor of the company was the fact that they
owned their own supply of water and generated electricity from it for
mine use. They figured this power cost $2 per horsepower per month,
or less than one-half the rate then being charged by a public utility
company near by.
Waterman Prospect comprises two claims, the Fairfax, 600 feet
long, and Centennial, 1500 ft. long, and a millsite, all in Sec. 3, T. 2
N., K. 13 E., adjoining the Madison Mine on the south. The country
rock is the amphibolite schist of the Angels Camp mines.
A shaft 225 ft. deep has been caved for years. The work of the
Waterman Mining Company about 1914 was stopped after some
diamond drilling had been done and a concrete foundation placed
around the shaft collar.
A 'diorite dike' or rib of unaltered rock adjoins the vein on the
hanging wall (east) side of vein and it is claimed the vein can be
traced from the north end of the Gold Cliff through the Madison and
Waterman claims. It is similar to the material mined in the former
properties. The fissure narrows on the surface about 800 feet north
of the south line of the Centennial. The owners report that several
of the diamond drill holes indicated milling ore of good width. Assays
on the surface indicated grades to be expected in the schist ores of the
district with occasional much richer spots. Drill holes giving the
reported good assays reached 300 feet in depth.
ZiegJer and North End claims (later called Etna King Mine)
are between the Gold Cliff and Utica Mines at Angels Camp. Early
in 1897, an adit had been run along the vein for 180 ft., showing a
body of ore which was believed to be from 25 ft. to 40 ft. wide. There
is no record of production at that time, however.
152 CALAVERAS COUNTY
Late in 1904, Etna King Mining Company put a plant, including
20 stamps, on the claims and worked for several years, making some
production in 1904, 1908 and 1909. A vertical shaft was sunk 240 ft.
and levels called 100-ft. and 200-ft. were run 200 and 300 ft. respec-
tively on the vein. A small stope was worked above the 200-ft. level.
The property was closed, it is said, because of financial troubles.
The vein is a westerly branch of the Mother Lode and is said to average
12 ft. wide, consisting of a stringer lead in amphibolite schist. The
recorded amount of ore milled was less than 3000 tons.
In May, 1913 this company sued Utica Mining Company for tres-
pass.
MOTHER LODE GOLD BELT 153
TUOLUMNE COUNTY.
Geology.
The Mother Lode traverses Tuolumne County for a length of
nearly 15 miles, extending from Robinsons Ferry on the Stanislaus
River, through Whiskey Hill, one mile west of Jamestown, through
Quartz Mountain and Stent, thence southeast along the east side of
Woods Creek and Tuolumne River.
The mines along this section of the lode have been found in the
amphibolite schist or along the contact of that rock, or serpentine or
other metamorphosed igneous intrusives, with the Calaveras (Car-
boniferous) rocks. The Mariposa slate lies west of the principal mines
and although it extends the whole length of the county, not a single
important mine has yet been found in it, though some are near its
contact with the amphibolite schist. The region extending from a
mile northeast of Chinese Camp to two miles northwest of Rawhide
Mine, a length of 6^ miles and a width of two miles, is occupied by a
large body of altered diorite, and another, on the east, of serpentine.
The principal mines (except the Eagle Shawmut) follow closely the
contact of this serpentine with the Calaveras rocks. We have here a
condition similar to the case in central El Dorado County, where the
lode has changed its course because of, or has been forced aside by, an
immense body of intrusive rock. The displacement, if such it is,
amounts to about a mile and a half to the east, going north on the lode.
The difficulty in proving a fault here is twofold; the Mariposa slate
maintains its normal course, and the canyon of Sullivan Creek is in
the homogeneous amphibolite schist, where jio contacts exist for
markers.
Although the Mother Lode in this county is found in rocks of
basic igneous nature its course is marked in many places by immense
outcrops of white quartz and silica-bearing ankerite. Such 'bull-
quartz' veins may be seen at Quartz Mountain, Whiskey Hill, Golden
Rule Hill and Eagle Shawmut mine. These outcrops occur with
broad zones of ankerite which are seamed with a network of quartz
veinlets. The ankerite decomposes to a rusty mass with a skeleton of
quartz and though it has often attracted the prospector, it has seldom
been found of value for milling, except at the Rawhide Mine.
The problem of these prominent quartz veins and the immense
quantities of ankerite so highly silicified, between walls of country rock
so loAv in free-silica content is interesting but not necessarily difficult.
One simple explanation for the presence of the silica would be that it
was deposited folloAving the intrusion of granodiorite and similar rocks,
and had its origin in their inagmas, representing deposition from cool-
ing vapors and solutions escaping from the magma into the lode fissures
and depositing silica when temperature and pressure dropped suffi-
ciently to permit. Granodiorite and related rocks outcrop on both
sides of the lode in this region, and these outcrops probably are linked
to a buried batholith.
154 TUOLUMNE COUNTY
Ankerite is an iron-bearing dolomite containing more or less iron
carbonate in solid solution, according to various authorities. Knopf
distinguishes ankerite from the mixture of calcite, magnesite and fer-
rous carbonate by optical differences, and states that optical studies of
some specimens from the Mother Lode indicate the rock there is true
ankerite. Dolomite, however, according to F. W. Clarke,^ is generally
of marine origin, while magnesite most commonly is formed by the
hydrothermal alteration of such easily decomposed rocks as peridotite
and serpentine. The ankerite or mixed carbonate rock of this section
of the Mother Lode is undoubtedly derived from serpentine or peridotite
in most cases, though it may also come from the alteration of other
basic igneous rocks or their derivatives. Whether the rock in question
be a true ankerite or a mixture of carbonates, its manifest mode of
occurrence in the widely separated sections of the California gold belt,
nearly always in association with altered basic igneous rocks which
yield serpentine, corresponds closely to the occurrence of magnesite.
The network of opaline silica and quartz so characteristic of the weath-
ered outcrops of ankerite is another criterion tending to prove this
mode of origin. That the carbonate rock of this type is not uniform
or homogeneous chemically over even a small area is well known to
any field engineer who has made the simple test for solubility with
cold, dilute hydrochloric acid. Ankerite, otherwise white or gray when
fresh, is frequently colored green by the presence of mariposite, a
mica containing chromic oxide derived from serpentine or its parent
rock.
Another feature of the ores of the Mother Lode in Tuolumne
County to be explained is the greater proportion of sulphides here. It
is reasonable to refer this abundance of sulphides to the greater solu-
bility of sulphides in femic magmas, whatever may have been the
processes of alteration, solution and final deposition in the form of ore.
Ores.
The ores of the Mother Lode in Tuolumne County are not free
milling in the same sense as are those of the mines in the Mariposa
slate. A much greater proportion of the gold is associated with
sulphides, principally pyrite, as depth increases. Some exceptions have
occurred, as at the Jumper and Rawhide, but as a rule, the percentage
of sulphide is two to three times as great as in Amador County quartz-
slate ores, and the ores in depth are largely of medium or low grade.
This has affected the methods of treatment used in later years.
There is no complex ore-treatment problem. Generally the con-
centrate is low grade and it would be an advantage if concentrate
could be treated on the properties to save freight and treatment charges.
1 Clarke, F. W. The Data of Geochemistry. Bull. U. S. Geol. Survey No. 770.
MOTHER LODE GOLD BELT
155
Geography, Climate, Water, Timber.
The Mother Lode courses along the -western foothill section of the
county, the elevation varying from 1000 feet in the southern part to
1700 feet at Quartz Mountain. In common with the rest of the lode,
this section enjoys a mild, dry climate. Snow seldom falls and never
lies on the ground more than a few days. Summer temperatures are
often high, but the absence of humidity prevents discomfort, and heat
prostrations are unknown. There is usually no rain from June until
October. The annual average rainfall at Sonora, four miles east of
the Mother Lode, is 35 inches. At Jamestown the average length of
the growing season, over a period of 12 years, was 210 days.
Gold and Silver Production of Tuolumne County, 1880-1933
Year
Gold,
value
Silver,
value
Year
Gold,
value
Silver,
value
1880
$461,861
500,000
400,000
320,000
310,000
320,903
432,438
504,662
475,000
446,300
1,500,629
1,384,950
1,092,549
354,734
547,448
666,754
1,070,141
1,809,572
1,734,953
1,635,769
1,596,891
1,670,368
1,791,829
1,732,572
1,563,907
1,291,726
1,039,675
806,875
$1,071
1,000
1908
1909
$798,752
925,703
615,626
1,093,484
1,113,291
974,409
940,793
1,058,103
868,237
321,085
274,328
471,021
254,569
96,026
222,366
261,936
255,994
155,592
119,873
40,209
36,807
70,957
67,691
77,902
93,939
107,736
$11,732
1881
4,384
1882
1910
5,754
1883
1911
13,243
1884
1912
25,146
1885 . .
1,473
1,551
3,166
3,500
543
13,062
139
911
1,329
1,072
313
328
1,696
15,582
15,111
62,367
39,787
6,580
13,989
12,963
21,348
8,476
6,453
1913
24,381
1886
1887
1914
1915
12,017
13,480
1888
1916
17,039
1889
1890 .
1917
1918
7,808
21,425
1891
1892.
1919
1920
11,076
6,007
1893.. .
1921
2,505
1894...
1922
2,976
1895
1896 _
1897
1898
1899
1900
1923
1924
1925 _
1926
1927
1928
2,801
1,106
614
1,119
302
185
1901.-
1929
2,735
1902
1903
1904
1905
1906
1907...
1930
1931...
1932
1933..
Total values.
300
180
214
280
$38,778,935
$422,619
The Mother Lode is crossed at several places by the Sierra Railway
of California, which connects with transcontinental lines at Oakdale,
30 miles west of Jamestown. The mines are all reached by good roads,
branching from either the Yosemite highway, which enters from the west
and runs near the lode from the vicinity of Jamestown southward to
the county line, or from the Mother Lode highway, entering at the
north.
Water and electric power along the lode are supplied mostly by a
public utility. The three forks of Stanislaus River drain the northern
part of the county and Tuolumne River the southern, but are not well
situated for cheap utilization in mining.
Lumbering is the most important industry in the eastern part of
the county, and large sawmills about 15 miles east of the lode can
supply a variety of pine lumber. Logs for mine timbers are plentiful
within 20 to 25 miles.
Alabama Mine adjoins the Crystalline on the north, covering 2600
ft. along the course of the Mother Lode. It was found in 1856 and up
to 1890 was worked by an open cut 150 ft. long. It had a 40-stamp
156 TUOLUMNE COUNTY
mill which handled 60 tons a day, and the cost of mining and milling
was low, probably about $1 a ton. Later an inclined shaft was sunk
300 ft. deep from the bottom of the cut (which was about 100 ft. deep).
The estimated production was $150,000. The last reported production
was in 1909, when 2302 tons yielded $3,765 gold and $52 silver.
The lode on the Alabama has a width of 60 ft. It is at the contact
of serpentine and Calaveras rocks and shares the characteristics of the
Crystalline.
. The last work done on this property was in 1922 and 1923, when it
was prospected by a drift which was run north from the 600-ft. level
of the Crystalline to a point beneath the Alabama shaft, 820 ft. north
of the south line. After passing out of the grey schist and 'bull
quartz, ' about 80 ft. north of the property line, this adit revealed slate
and schist with several faults crossing the line of adit in a distance of
360 ft. It then encountered the 'bull-quartz' vein which was fol-
lowed about 400 ft. A layer of brown schist two ft. wide lies between
this and the hanging-wall slate.
So far as known, no crosscuts were run and the option was relin-
quished without any ore being crushed.
Alameda Mine is three miles northwest of Jamestown. It is just
north of where the serpentine and Calaveras rocks turn west, and the
lode courses northwest along a narrow dike (originally diabase but
altered to amphibolite schist) which was intruded into the contact zone
between the serpentine f ootwall and the Calaveras formation on the
hanging wall. This dike is an outliner of the large area at Jackass Hill.
No definite details of early operations are to be had. The claim
was worked superficially for a length of nearly 1000 feet. On the
south end of claim the east vein was stoped to a depth of from 40 to 70
feet and a thickness of 18 inches to 2 ft. The south shaft was sunk
400 ft. deep to work this vein. Adits were also run to the vein from
the east, the longest of them reported over 800 ft. long and 500 ft.
deep, but apparently no ore was stoped from it.
Further north, the stringer lead or footwall vein widens to 160 ft.
It is composed of stringers and small lenses of quartz in the typical
ankeritic and talcose material of the region. The north shaft was sunk
there to a depth of 920 ft. and six levels were run, with a total of
about 3000 ft. of underground work. At the 600-ft. level, the vein was
reported two to 12 ft. wide and on the 900-ft. level, 13 ft. wide. No
information about assay values is to be had ; the mine has been idle
over 20 years. The east vein is reported to have milled $20 a ton.
There is no equipment on the property.
App Mine at Quartz IMountain was worked at intervals between
1856 and 1859, and thereafter steadily for many years on a small scale.
The fragmentary records available are interesting. In 1873, the shaft
had reached a depth of 800 ft. Ore that gave an average return of
$15.52 a ton was found in the upper levels, where there were three ore-
shoots 75, 100 and 135 ft. long. These united at a depth of 180 ft.
but gave out at 350 ft. deep and no more good ore was found until the
650-ft. level was run north in 1871-1872 and encountered an orebody
112 ft. long and 8| ft. wide, assaying $14 a ton. During the late
1880 's the product was small. The mine was evidently unproductive
MOTHER LODE GOLD BELT 157
from 1890 to 1897, when it became an important producer and con-
tinued to be one except for short shut-downs, until 1920.
During these years the App was part of three different consolida-
tions. In 1893 in connection with the Heslep Mine, it formed part of
the App & Heslep Mining- Company. A new shaft was sunk and
raised (using the old shaft as a working entry) on the footwall side of
the ankerite and a new 20-stamp mill was erected. Thereafter the two
mines were worked together until 1912 when a depth of 1340 ft. had
been reached. In 1902 and later the operators of the App also worked
the Rawhide Mine, and production figures were not always separated
for the two. Again between 1915 and 1920, the Dutch, App, Heslep
and adjoining claims were grouped and operated by Pacific Coast Gold
Mines Corporation. That company did the last deep work on these
claims. Because of these consolidations, it is impossible to allocate to
each of the mines its exact production. For the App, a few production
figures are informative.
From May 1, 1859, to September 1, 1866, a total of 8027 tons of ore
yielded $124,575 or $15.52 a ton at an average mining and milling cost
of $7.47 a ton. This was between the surface and 350 ft. deep.
In 1906, when the workings were 1300 ft. deep and a 60-stamp
mill was in operation, 57,600 tons of ore yielded about $288,000 in gold
and $3,300 silver including $77,000 gold and $1,200 silver from 1750
tons of concentrate. This indicates an average recovery of $5.06 in
gold and silver, and concentrate of a value of nearly $45 a ton, forming
a little more than 3^/c of the ore.
In 1909, the App Consolidated yielded 87,000 tons of ore which
gave in round numbers $320,000 gold and $1,676 silver including $140,-
000 gold and $223 silver from 4000 tons of concentrate. From a total
recorded production of $1,617,308 from 1888 to 1917 which can be
credited to the App and Heslep with fair certainty, a weighted average
recovery of $3.88 a ton is obtained for the period 1906 to 1912, inclusive,
when 353,600 tons of ore was crushed. (See also Dutch Mine.)
Geology. The Mother Lode, as it passes through the several claims
mentioned above, consists of a series of veins with a total width varying
from 40 ft. on the north to 300 ft. at the south, forming at Quartz
Mountain the central part of a hill 250 ft. high. The eminence is due
to the hard quartz of the 'bull quartz' vein. The lode system is
composed of quartz lenses and stringers, included fragments of wall-
rock, serpentine, dikes, mariposite and ankerite. The weak zone at and
near the contact of the Calaveras (Carboniferous) slaty schists and the
hard amphibolite schist of the hanging wall has been a favorable place
for movement, dike or sill intrusion and hydrothermal action. The
veins in this zone are: West, App or Footwall, ^Middle. Heslep, Whit-
ford (in Heslep claim). Bull Quartz, and Knox & Boyle. The various
veins may pinch and form lenses or break into stringers and are not all
continuous throughout the group of claims. The App (Footwall) vein
was principally worked in that mine, the Heslep and Whitford in the
Heslep, and the App, jMiddle and Heslep veins in the Dutch.
The immediate footwall rocks are meta-andesite and serpentine, and
amphibolite schist forms the hanging wall.
The Pacific Coast Gold j\Iines Corporation working through the
Dutch shaft, explored the App and Heslep veins on the 1350-, 1500-,
158 TUOLUMNE COUNTY
1650-, 2050- and 2300-ft. levels, below depths reached in the old work-
ings. Ore was mined and milled from the 1500-, 2050- and 2350-ft.
levels.
The Footwall (App) vein averaging 10 ft. wide on the 1500-ft.
level has the Bull Quartz vein for hanging wall; the Heslep vein, 15
to 20 ft. wide, is on the hanging wall side of the Bull Quartz. The
Middle vein comes within 5 to 10 ft. of the Heslep vein above the
1500-ft. level and they were mined as a whole, 30 to 40 ft. wide. The
veins strike N. 35° to 45° W. and dip about 65° NE. While the ore
is sometimes solid quartz it is usually a stringer lead between a foot-
wall of gray schist and a hanging wall of black schist, and may show
the varying characteristics of 'schist ore' and ankerite. The per-
centage of sulphides appears to have been higher in the later work;
the last company reported as much as 8% to 10% of sulphides, mostly
pyrite. The apparent increase may have been due in part to release
of more sulphide from the finer grinding for flotation.
At present there is no equipment on the claims.
Atlas Mine, a mile north of Tuttletown, is another of the Jackass
Hill mines in amphibolite schist. The surface was worked for pockets
in early days for a length of 1000 ft. Later a shaft was sunk 375 ft.
and from 1913 to 1916 a few hundred tons of picked ore was produced,
yielding from $13 to $55 a ton. The pay occurs in a stringer lead 10
to 30 ft. wide, and the percentage of sulphides is high, 6% to 10% of
the ore, but the concentrate is low grade as is usual on Jackass Hill.
There is a 10-stamp mill with five concentrators, small electric
hoist and air compressor, and tramway 600 ft. long from the mine to
the mill.
From 1929 to 1931, F. H. Bernard worked the property and
reported substantial production for 1931. There was also some activity
in 1928 when Mark Twain Mining Company worked the Atlas and
Chileno.
Arhona Mine adjoins Tuttletown, east of the main lode and south
of the Patterson in the amphibolite-schist area containing the Jackass
Hill mines. The vein, from 3 to 10 ft. wide, has been prospected by
an inclined shaft 600 ft. deep with four levels at 100, 200, 350 and
500 ft. Two brief periods of activity are recorded — in 1900 and 1901
when about $6,000 was produced, and again in 1908-1909 when about
3000 tons crushed gave a return of $1.92 a ton. The concentrate dur-
ing these two years averaged a little over $18 a ton. A few ounces of
pocket gold was mined here in 1931,
Bell Mine, on the Mother Lode one mile west of Tuttletown, has
been prospected by a shaft 630 ft. deep, sunk on the dip of the vein
70° to 74° E. Six levels were turned, the first at 40 ft. in depth and
others about 100 ft. apart, but most of the work was done on Nos. 3, 4,
and 5. The vein was explored for a maximum distance of 158 ft.
north (on No. 5) and 180 ft. south (No. 4). Crosscuts are reported to
have shown the following as an average cross-section, beginning at the
Calaveras slate footwall: gouge, 5 ft.; ankerite, 6 ft.; 'grey banded
schist,' 8 to 10 ft.; heavy quartz vein on hanging wall, which is
amphibolite schist. The ore is reported to consist of quartz stringers
and mineralized schist.
MOTHER LODE GOLD BELT 159
El Rico Mg. Co. did the last work on this claim in 1902-1904, and
had a 10-stamp mill in which many mill tests were made; but the
present owners claim to have no records of the results of these tests.
There are two old buildings but no equipment on the claim.
Bown Mine is one-half mile south of Robinsons Ferry (Melones).
In 1900, a shaft was sunk 700 ft. on this claim, at an angle of 64°, in
the footwall and the vein was reached by crosscuts on the 200-, 300-,
400- and 600-ft. levels. According to Storms, the vein is 10 ft. wide
between an ankerite hanging wall and schist and serpentine footwall.
On the 400-ft. level, a crosscut was run 128 ft. into the hanging wall.
A 20-stamp mill which was put on the property about 1900 was oper-
ated only a short time, when the mine was closed down and has been
idle since, all equipment having been removed.
The only production of record was less than $500 in 1900, but ton-
nage milled is unknown,
Cliileno, Carrington, Rice, Santissima, Stacker, J. A. Gillis, Wil-
son & Means, Pine Tree, Last Chance and other claims on Jackass Hill
near Tuttletown are near the center of a mile-wide area of amphibolite
schist. They lie about one-half mile east of the course of the main
Mother Lode which passes along the west side of the schist.
The mines on Jackass Hill have been known principally as pocket
mines, and are reputed to have produced about $500,000 from a great
number of shallow holes.
In 1922, the claims named were taken under option by Nevada
Wonder Mining Company. A shaft was sunk on the Chileno claim
to a depth of about 500 ft. on an incline of 74° and levels were turned
at 150 and 450 ft. On the 150-ft. level, encouraging assays were
obtained at intervals over a length of 160 ft. On the 450-ft. level, over
1000 ft. of work was done, of which over 500 ft. was in crosscuts, but
results on that level were disappointing and the option was abandoned
after mill runs of 600 tons had yielded about $1.03 a ton.
The Chileno was then taken under lease and option by others and
by them turned over to Mark Twain Mining Company, incorporated
1924 with $200,000 capital. Although the first few hundred tons of
ore milled in 1925 assayed well, the average yield of about 3000 tons
crushed was too low to pay expenses. To compensate in a measure, the
operations, which had been expanded to take in the Atlas and other
claims, in 1928 yielded nearly $10,000 in pocket gold. Since then the
company has done little and have given up the claims, on some of
wliich work was begun by others in 1933.
The ore occurs as a stringer lead of quartz and calcite in thor-
oughly altered amphibolite schist, with albite and sericite. In the
mineralized zone which is from 4 to 9 ft. wide the schist is nearly white.
Pyrite occurs, often in coarse crystals, and forms up to 15% of the
ore. This pyrite carries most of the gold but assays only about $20
a ton.
Clio Mine is on Tuolumne River one-half mile south of Jackson-
ville. The original holdings included two patented and three unpat-
ented claims. The group was enlarged by leases and options on adjoin-
ing land during the later operations, including the Imperial Gold
Mines, Bell Boy and West Clio claims and E. R. Bolton land, making
160 TUOLUMNE COUNTY
a total of 637^ acres. Much of this land has since reverted to the
previous owners and the Clio and other claims of the original group
have been sold to the State for taxes.
This mine "svas first equipped with a 10-stamp mill in 1862 or 1863
and was worked five or six years, with recurring periods of short-lived
activity up to 1926. The last company began work in November, 1919,
and milled small tonnages of ore at intervals from April, 1920, until
1926. These later operations were unprofitable on the whole.
The northern part of the Clio claims is in the rocks of the
amphibolite schist series. To the east, in the leased ground, and on
the southern end of the claims, the workings entered some members of
the Calaveras series, forming a narrow lens in the amphibolite schist.
The footwall of the vein is serpentine, altered from peridotite. The
hanging w^all is one or another member of the schist series and in part
the Calaveras rocks. The amphibolite schist, about a mile wide here,
encloses the rocks named. To the west of it occurs altered diabase,
then Mariposa slate. The mineralizing solutions found access at the
Clio mine by invading the structurally weak contact zone between the
serpentine on one side and schists or Calaveras formation on the other.
The ore is altered amphibolite schist and as described by Knopf also
included mineralized members of the Calaveras and chloritic schist.
Some of the ore was in the form of quartz stringer leads, and dolomitic
sulphide ore. Ore had a maximum width of 40 ft. but averaged 8 to
10 ft. The footwall serpentine was troublesome on account of sw-ell-
ing, and carried a heavy gouge. The ore was generally low grade,
carrying $3.50 to $6 a ton in gold, mostly in the pyrite which formed
37c to 5% of the ore. Gold bullion was worth $12.68 an ounce.
The earlier work w^as through an adit called the 218-ft. level, and
there was a total of 1100 ft. of drifts on this level. A 3-compartment
shaft on an incline of 67° was later sunk to a depth of 930 ft. with
levels at 306, 361, 473, 565, 700, 800 and 900 ft. The longest drift on
these was 480 ft. on the 565-ft. level, and there was a crosscut 313 ft.
east on the 900-ft. level.
The last reduction plant included 10 stamps, 3 Wilfley concen-
trators and a Vandercook mercuric cyanide outfit of 50 tons daily
capacity. An extraction of 90% to 94% was reported.
Most of the material milled in the later operations was not ore
under then existing costs, as it yielded only a little over $2 a ton on the
average; although some small tonnages, less than 10% of that milled,
paid from $5 up a ton. The deepest stoping was for a length of 160
ft. and width of 8 ft. on the 800-ft. level.
Crystalline Mine is north of the Harvard, a mile and a half west
of Jamestown, on a contact between the Calaveras formation on the
hanging wall and a large dike of serpentine on the footwall. There
are two claims. Crystalline and Shore, parallel and each 1500 ft. long.
The early work was done in an open cut and ore was taken out
through a tunnel and crushed in a 15-stamp mill during irregular
periods of operation previous to 1890. Later a vertical shaft was sunk
625 ft., and an inclined shaft 300 ft. deep, and 750 ft. south of the
first. From these, the vein was explored on the 300-ft. level from the
south shaft to a distance 400 ft. north of the vertical shaft. On the
600-ft. level, the east and west veins were both prospected. The mine
MOTHER LODE GOLD BELT 161
has the three veins of the lode system, showing the usual local aspect
of a central vein of 'bull quartz' with east and west stringer leads, or
schist and sulphide ores.
In 1922 after the claims had been idle for years, the vertical shaft
was unwatered to the 600-ft. level by Tonopah Mining Company and
a drift was run along the vein system from the face of the old workings
to the northerly property line and beyond, to a point under the Ala-
bama shaft. The veins at this level pass on the dip eastward under
the Shore claim. The formations traversed in this drift were the
stringer lead of the 'bull quartz' vein, talc schist, talc mixed with
quartz, and grey and black schist. The time agreed upon for pros-
pecting work was not sufficient to permit of driving crosscuts ; the drift
followed quite closely the 'bull quartz' vein which is practically
always low-grade and the two other veins were not explored to any
extent, though it was found there is a mineralized zone about 150 ft.
wide in the east vein section in the crosscut farthest south of the shaft.
This was low grade along the above crosscut.
The workings at the time of the above work made about 10,000
gallons of water daily, most of which came from the 300-ft. level or
above. It was handled by bailing.
Dutch Mine, at Quartz Mountain, was an early location but was
worked in only a small way until 1891, when production exceeded
$10,000 for the year. In 1892, there were four shafts on the claim,
ranging in depth from 80 ft. to 210 ft. The production that year was
$25,780 and ore was crushed in the App mill. The grade of this ore,
which ranged in reported yield from $3 to $125 a ton, must have been
high on the average, as the mill had only five stamps with an average
capacity of only three-fourths ton per stamp-day. Late in 1896, one
shaft was 430 ft. deep and 10 stamps were in operation on the mine.
From then until 1906 the mine was in steady operation and produced,
according to available figures, $780,662, the mill having been enlarged
to 20 stamps in 1902. In 1906, the shaft had reached a depth of 1720
ft. and the ore decreased in grade. The mine was unproductive from
then until 1910, when it was again put in operation after consolidation
with the Sweeney claim on the north. From then to 1917, a 40-stamp
mill was kept in fairly steady operation. A total length of 1800 ft.
was explored along the strike, and 1867 ft. in depth on an incline of
65° was reached. An ore zone reported 1000 ft. long was stoped
for an average width of 20 ft. Ore occurred in it in shoots running
diagonally.
During this period the gross production was $1,126,689 and yield
varied from $2.20 to $4.40 a ton. Concentrate varied in value from
$35 to $42 a ton and formed from 3^% to 5% of ore. Operating cost
early in 1914 was reported as $2.31 a ton.
In 1917, the Dutch, App, Sweeney, and Heslep were consolidated
by Pacific Coast Gold Mines Company. The Dutch shaft was deep-
ened to 2350 ft. inclined depth (2070"^ft. vertical). About 17,000 ft.
of new development and exploration work was done on the App and
Heslep veins on the 1350-, 1500-, 1650-, 2050- and 2300-ft.. levels. A
large part of the work was done on the 1500-ft. level and ore from there
and from the lowest two levels was milled. The App and Heslep claims
11—4156
162 TUOLUMNE COUNTY
were prospected by some of these levels. The Heslep ore shoot was
reported 400 ft. long on the 1500-ft. level, but at 2300 ft. had shortened
to 40 ft. In the Dutch, ore shoots crossed the lode diagonally from
footwall to hanging wall, and pitched north. The App, Middle and
Heslep veins were worked there. The maximum width stoped in the
Dutch (not by last operators) was 60 ft. between the 600- and 800-ft.
levels. The grade of ore developed in the App and Middle veins by the
last company did not permit working at a profit with their high costs
during war time, and they closed the mines in 1920. During 1919
and 1920 they operated an expensive mill and flotation plant in which
54,433 tons of ore was treated. This yielded $175,447, of which $133,-
516 came from 2616 tons of concentrate. The ore treatment is men-
tioned under Metallurgy.
Eagle Shawnntt Mine (Belmont-Shanmiut) has been described
many times. The Eagle claim was worked at an early date, but no
records of the results remain. The Eagle Shawmut Mining Company
began work about 1895. The earlier operations had been through
shafts sunk on the prominent outcrop. The company reopened the
mine through adits driven from near Woods Creek, the main adit, 1100
ft. long, connecting with one shaft 450 ft. below the outcrop. The
shaft was deepened to 2250 ft. and a winze in later years was sunk 900
ft. farther. In 1916, the mine passed under lease and option to a sub-
sidiary of Tonopah Belmont JMining Company and for seven years
was operated as the Belmont-Shawmut Mine. After being turned back
to the owners in 1923 it was operated until early in 1926. Since then
it has been idle; the mill was cleaned up in 1929 and most of the
machinery has been sold.
The total production of the property from 1897 to 1926, inclusive,
has been nearly $5,380,000. No record of tonnage of ore mined
previous to 1902 is available. From 1902 to 1910 the weighted average
recovered value of ore was $2.20 a ton. From 1911 to 1926, inclusive,
the weighted average recovered value per ton was $3.90. Most of the
gold and silver (the latter very subordinate in amount) was obtained
in the sulphides. In 1906, when the ore returned only $1.84 a ton, the
concentrate formed 3% of the ore, yielded over $41 a ton and contained
70% of all gold recovered. In 1915, when the ore was above the
average, yielding over $5 a ton, 52,382 tons of ore yielded 5985 tons of
concentrate of an average value of $39 a ton, containing 85% of all
gold and silver recovered. This condition led Belmont-Shawmut Min-
ing Company to radically change the method of ore treatment, doing
away with amalgamation entirely, and depending first on flotation
and finally on table concentration. (See Chapter on Metallurgj% where
the flow sheet used is discussed.) In the last three full years opera-
tion concentrate averaged from 5% to 8% of the ore.
The ore occurs in a broad fracture zone, filled with quartz stringers
and with much ankerite or dolomite, on the hanging wall of or within
a basic dike, composed largely of basic feldspars. The 'bull quartz'
outcrop is coextensive on the surface Avith the ore below. The footwall
is a metamorphic complex of the IMariposa formation, largely schist,
slate with narrow bands of sandstone, and limestone. The hanging
wall is the Calaveras formation. Knopf has discussed the geology of
the mine in detail and has summarized the sequence of events leading
MOTHER LODE GOLD BELT 163
to the formation of the ore, as follows: (1) "A basic plutonic rock
(hornblendite, pyroxenite or peridotite) was intruded along a reverse
fault fissure between the Calaveras and Mariposa formations. (2)
Renewed movement on the fault highly sheared the peridotite and con-
verted it into various chlorite schists, and at the same time auxiliary
fractures were formed in the hanging wall rocks; (3) ascending miner-
alizing solutions altered the compact chlorite schist to bodies of sulphide
ore and the other schist to quartz-ankerite rock, in which the quartz is
locally so abundant as to form thick masses such as the Bull vein.
Concomitant with this action the Shawmut vein was formed near or
along the hanging wall of the sheared pyroxenite dike, and the sub-
ordinate or auxiliary fractures in the hanging-wall country rock also
became filled with low-grade gold-bearing quartz."
Several varieties of ore have been worked. Siliceous ores occurred
in stringers in the Calaveras rocks and where silicified masses of the
wall-rock were caught up and held by the intrusive rock; also along
or near the contact of intrusive and Calaveras rocks, where the Shaw-
mut vein produced much of the low-grade ore mined in earlier opera-
tions. This strikes N. 32° W. and dips 70° E. On the footwall side
between 1100 and 1400-ft. levels the ore and gouge were in contact and
gouge swelled badly. Below 1400 ft. they were separated. On the 17th
level the workings entered the dolomite or anker ite for the first time.
In depth the dolomite-sulphide ore was principally mined. It occurred
in well-defined overlapping lenses 8 ft. to 30 ft. wide. The ore was
found on the crests of anticlines in the vein. Its sulphide content
averaged as much as 8% of the ore (mostly pyrite) over a full year's
operation, though locally higher.
The main shaft, long since caved above the adit level, has three
compartments and is on the vein which has an average dip of 68° E.,
to between the 1,1th and 12th levels, then on an angle of 65°, being 80
ft. from the vein in the hanging wall at the 18th level. Its bottom is
one-half way beween the 19th and 20th levels and is 2250 ft. vertically
below No. 2 adit, which is 450 ft. vertically below the surface. The
winze is sunk from the 19th level and the bottom of the 21st level is
3213 ft. on the slope below the surface.
Because of the heavy and caving nature of the vein, drifts were
carried in the firm hanging wall and ore was developed by crosscuts.
When the Tonopah Belmont Development Company took the property
they excavated a large room on the adit level for a headframe and
hoist, and installed pumps on the 16th and 18th levels. In 1918 they
remodeled the mill (see under Metallurgy), retaining 70 stamps for
crushing. For the last half of 1918, their experience gives a good
idea of the reasons why so many low-grade mines closed during the
war period. Wages for miners increased 26% and for millmen and
mechanics 38% over those for 1917. Efficiency of labor at the same
time decreased 65% of normal effort, and the labor turnover reached
280% in one month, although the company furnished very good board
at rea,sonable cost, and working conditions were no worse than at other
Mother Lode mines. The cost of mining supplies advanced 27.7%,
the cost of water jumped from 12^^ to Sliij! per miner's inch daily,
electric power cost increased 36% and freight rates and smelter
charges were raised to such an extent that concentrate, which con-
164 TUOLUMNE COUNTY
tained most of the gold produced, could not be profitably shipped. In
short, what had appeared to be an attractive opportunity had in a
short time been transformed by outside and uncontrollable conditions
into a strenuous struggle to make both ends meet.
Gold Ridge Mines, Incorporated. This is the last of several com-
panies formed to work prospects on the Jones agricultural patent in
Sees. 1 and 2, T. 1 S., R. 14 E., adjoining the Tarantula on the east,
and containing 220 acres. In 1921, Tuolumne Giant Gold ]\Iines Com-
pany had this land but did onl}^ a little work. The ground is on the
east of the Mother Lode proper and covers a series of veins. On the
east or hanging-wall side is the* hanging-wall vein. The Jones vein,
800 ft. west of above, is a zone of quartz stringers 80 to 140 ft.
wide in amphibolite schist. The Reitz vein, 600 ft. west of the Jones,
is a solid quartz vein about 2^ ft. wide where seen. About 650 ft.
further w^est is a stringer lead in black slate (in the hanging w^all of the
Tarantula vein), opened by the old Mexican Hill diggings some 800 ft.
south of the line of the Tarantula adit if this were extended on its
present course.
The last named company planned to prospect these veins by extend-
ing the Tarantula adit eastward, and this would give depths increasing
from 400 ft. at the west property line. Nothing was ever accomplished
in this connection. The only workings are shallow shafts, and numer-
ous old open cuts and pits mostly dug many years ago by pocket-
hunters. The deepest work is the Gage shaft sunk 110 ft. deep 400 ft.
south of the north property line on the Jones vein, with about 100 ft.
of drifting. The present company apparently bases it-s hopes on this
stringer lode. Gold is said to occur where a series of flat quartz
stringers intersect vertical quartz seams, but zones rich in FeSj in the
schist may more probably be responsible.
Construction work on a new milling plant included the founda-
tions and part of the building for a 300-ton ball mill. Other machinery
planned but not installed at time of visit were crushers and concen-
trating tables. There is a good shop building housing a 60 h.p. motor,
420 cu. ft. compressor and drill sharpener.
Hai^riman Mine comprises three patented claims, named M. B.,
Sonora and Hayes on the Mother Lode a mile and a half south of
Jacksonville. The Willieta claim was also under option when the last
work was done by Harriman Mining and Milling Company and with
this the holdings covered nearly a mile in length. Oliver-Harriman
Mining Company, Ltd., is the present corporation.
At this place the Mariposa slates are about 1500 ft. in width and
are flanked on the east by serpentine and the Calaveras formation, with
dikes of diabase. The principal workings are at the contact with
serpentine on the footwall.
There are two shafts, both on the IM. B. claim. No. 1 or north
shaft is 500 ft. deep on 61° incline, with levels at 200, 350 and 500 ft.
inclined depth. This shaft has two compartments to 350 ft. in depth
and the balance has three compartments. Drifts have been run 280 ft.
south and 150 ft. north on the 350-ft. level. The south drift is on the
vein averaging probably 8 ft. wide, with one crosscut showing 35 ft. in
width which is reported by the company to average $4 a ton. This ore-
MOTHER LODE GOLD BELT 165
shoot is believed to be 100 ft. long. It has a soft black serpentine foot-
wall and a hard diabase hanging wall which has been crosscut for 70 ft.
The south drift on the 200-ft. level is 570 ft. long, connecting with
No. 2 shaft. The 500-ft. level was under water at time of last visit in
October, 1927.
The entire mineralized formation is 180 ft. wide, of which the
portion next the serpentine is the footwall or 'bull-quartz' vein. In
the south shaft workings at the 120-ft. level (probably inaccessible
now) the diabase dike and later grey dikes run parallel. A zone of
stringers in the diabase carried free gold where they ran to and were
cut off by the grey dikes, forming small 'pockets' or concentrations of
gold. The amount of such ore was small. A crosscut was run on that
level 116 ft. east.
There is an electric hoist, air compressor of 340 cu. ft. capacity,
10-stamp Straub mill and one concentrator on the property.
Harvard Mine (Whiskey Hill Mine) is one mile southwest of
Jamestown, covering the southeast slope of Whiskey Hill, which owes
its prominence to one of the series of massive quartz and ankerite out-
crops characteristic of the lode in this county. The group of claims
covered nearly a mile along the strike during the period of operation,
including the McCann, Mooney, Trio and Sobrante claims and Mooney
mill-site.
It was discovered in 1850 and was worked at intervals until Octo-
ber, 1916, since when most of the surface plant has been removed. The
Trio and Mooney claims, when worked in early days, produced ore
containing about $4.75 a ton in gold and most of the ore has been
medium- or low-grade, although one narrow vein at the serpentine
contact in the south workings produced a small tonnage of very rich ore.
The claims lie at the contact of serpentine which forms the foot-
wall, and amphibolite schist and Calaveras rocks on the hanging wall,
there being a dike of altered andesite in the contact at this place. The
croppings of the lode are 100 ft. wide near the highway and 300 ft.
wide on the north end of Trio claim on Whiskey Hill. The central or
boulder vein of 'bull quartz' is prominent, but as usual is for the
most part very low in gold content. The ore occurred mostly in the
stringer leads of the east and west veins and was partly black slaty
material but largely the mineralized gray schist resulting from altera-
tion and pyritization of amphibolite.
The principal period of activity began about 1900, the 60-stamp
mill having been built that year. The mine was opened through two
shafts, 1000 ft. apart. The north shaft, 700 ft. deep, was not used in
later work. The south shaft was sunk vertically for 700 ft. Between
there and the 800-ft. level the shaft entered a gouge 15 ft. wide, lying
on the serpentine footwall, which was also so soft as to require special
timbering. Double sets were used, to afford space for taking the swell-
ing ground. To obviate expensive maintenance in such ground, the
shaft was turned to an incline at 700 ft., following the vein on an angle
of 58° and finally reaching a depth of 1850 ft. Levels were 150 ft.
apart in the deeper section. Ore was mined by shrinkage with chutes
20 ft. apart. Seven orebodies averaging 200 ft. long and six ft. wide
were Avorked. The veins were found to be faulted eight to 25 ft. by
166 TUOLUMNE COUNTY
a series of strike faults between the 1150-ft. and 1850-ft. levels. Faults
struck N. 35° W. and dipped NE. 15°.
An operating cost of about $2 a ton was claimed in 1914 with 60
stamps crushing about 300 tons daily and with a total crew of 115 men.
After the war started, costs rose and higher-grade ore was sought. In
the last operations in 1917, an ore-shoot about 200 ft. long was found
on the 1850-ft. level north of the shaft. The small rich shoot on the
south, in contact with the serpentine, helped to 'sweeten' mill heads.
Under the conditions existing during the war, the owners did not feel
justified in sinking deeper, as would have been necessary to fully
develop the new orebody.
Usual Mother Lode practice- was followed in milling. The stamps
weighed 1200 lb. each and 20-mesh and 40-mesh screens were used;
added recovery with the latter did not appear to make up for reduced
capacity. Concentrate was saved on Johnston vanners. It was nearly
all pyrite, assaying $30 to $35 a ton in the last work. Total operating
cost was about $3 a ton. Milling cost 30 cents a ton, which was very
creditable compared with the cost at properties with similar ore, where
more elaborate flow sheets were used. The recovery was 85% to 90%
of mill-head assay value. The production of the Harvard from 1897
to 1916 was over $2,210,000. There is no record of the amount of pro-
duction before 1897 although both the Mooney and Trio were equipped
with stamp mills before 1867.
Very little work has been done on the Pacific and Vulture claims
which adjoin the Harvard Group on the south. This work, in the
form of surface cuts and a shaft 40 ft. deep, shows the characteristic
veins of the lode running through the claims which cover 2700 ft. in
length. The lode begins to narrow south of Whiskey Hill, and little
work has been done for about one-half mile, until the Sweeney claim
is reached.
Heslep Mine was located in the 1850 's and by 1867 the surface
had been mined at intervals for a length of 1200 ft., but nowhere over
90 ft. deep. The vein there was 8 to 20 ft. wide and recovery averaged
$8 a ton. In 1873, at a depth of 270 ft., the ore-shoot in the Heslep
vein was reported 10 ft. wide, 165 ft. long and milling value $9.75 a
ton, including the concentrate which formed 2^% of the ore and assayed
$40 a ton. By 1888, the Heslep shaft was 500 ft. deep and a 25-stamp
mill was in operation. After the consolidation with the App in 1893,
the tM'o claims were worked together until 1912. In that year a cave-in
occurred in the Heslep and 300 ft. on the north end was lost, to the
1000- ft. level.
In 1923, J. A. Keyes and associates obtained a lease on the part
of the mine above the 300-ft. level. They installed 12 stamps, and
for three years milled ore in small quantity. This came from the
Whitford vein, between the Heslep and Bull Quartz veins. The ore-
shoot was reported by Keyes to be 260 ft. long and to average 6 ft.
wide. This had been stoped up to the 400-ft. level before the cave-in
occurred. The remnant worked by Keyes yielded an average of over
$7 a ton in gold and silver. The amount of silver in this ore was
notably higher than in other veins of the district, at times exceeding in
weight the gold content.
MOTHER LODE GOLD BELT 167
The last deep work in the Heslep and adjacent claims was done
between 1915 and 1920 by Pacific Coast Gold Mines Corporation,
"^"^'^cMU mil Mines
^■Tfe^frjvf^: 777f ^-7W-2ji^g( See Cluleno et al.)
Jumper, Golden Rule and New Era Mines. The geology of these
mines, one-half mile south of Stent, is Avell shown in the accompanying
sections.
Golden Bide Mine was operated in the 1860 's and 1870 's, and was
said to have produced $48,500 in 1870 and 1871. At that time it was
worked by means of open cuts and a shaft 200 ft. deep. About 1895
it was reopened and developed by a crosscut adit 528 ft. long from
the footwall side, with drifts north and south for nearly 1000 ft. but
at a depth of only 70 ft. This work was done on a zone of chlorite
schist containing gold and auriferous sulphide ; on the footwall side
of this zone there were said to be narrow veins of quartz and calcite,
rich in gold. A vertical depth of 530 ft. was finally reached in the
shaft and a winze 800 ft. deep was sunk from the 493-ft. level. The
mine produced about $90,000 from 1899 to 1902, but total output
before transfer to the Jumper is unknown.
New Era Mine was also worked as a separate unit, through four
shallow shafts, for some years prior to 1895. The greatest depth
reached was only 100 ft. There is no separate record of production.
Ore was crushed at the App, and it was said the ore-shoot was 750 ft.
long. About 1895 this claim also became part of the Jumper, and as
such was later developed to a depth of 1800 ft. through a shaft 1400
ft. deep and a winze sunk 400 ft. below the 1400-ft. level.
Although the Jumper and above claims were reputed to be particu-
larly rich 'pocket' producers, this did not show in the average grades
of ore milled. The principal operations extended from 1896 to 1914,
when the mines were worked for company account by Jumper Cali-
fornian Gold ]\lines Company. Thereafter, until 1919, the work was
done by lessees. The period of hea^aest production was from 1896 to
1904. For the years when tonnage figures are available, the average
value recovered was $5.25 a ton. As shown on the sections, the mine
was extensively stoped down to the 800-ft. level, but little below there.
In July, 1899, when operations were in the zone from 300-ft. probably
to 600-ft. level, the mill ran 23 days, and crushed 3500 tons of ore
which yielded $27,500 or $7.85 a ton. During the same month, 810
tons from the Golden Rule east vein yielded $4,350 or $5.37 a ton,
whereas 700 tons from the middle vein returned only $1,110 or $1.58
a ton. Average yield of course in such a case, while interesting and
valuable to know, does not tell the whole story ; because from time to
time, as in April, 1895, rich strikes were made in the Jumper. At that
time, one blast on No. 1 level knocked downi $3,000 of 'high-grade'
and for some days very rich ore was found ; a quantity of it was said
to be worth $10 a pound.
While large quartz masses with some gold and auriferous sulphide
occur in the ankerite, the principal ore-bearing vein was in amphibolite
schist on the east of the ankerite. Along the footwall of a silicified
zone in this amphibolite schist, a narrow vein of quartz and calcite
168 TUOLUMNE COUNTY
occurred with a small gouge. This vein was frequently rich in free
gold. A dike of diabase was intruded into this zone and was noticed
to be larger on the Jumper than on the Golden Rule. The dike itself
was often mineralized and filled with quartz and caleite stringers,
forming ore. The superintendent, M. B. Kerr, believed the caleite
stringers were responsible for the presence of coarse gold. This prin-
cipal vein in the Jumper strikes N. 16° W., and dips 70° NE., and the
caleite seams strike northwest across it, and generally dip north. The
width of the principal pay zone is from 5 to 50 ft. Petzite occurs at
times with the gold. The w^est vein contained low-grade material in
large amounts.
The Jumper had a mill of twenty 1030-pound stamps in the 1890 's
and this was later increased to 40 stamps. Sulphides were apparently
too low grade to save.
For several years after the company quit, lessees worked in the
levels above 500 ft. Their total annual output varied from $8,000 to
$85,000, and the value per ton was from $1 to $15, reflecting the uncer-
tain occurrence of 'high-grade.' During the best year, only four sets
of lessees out of seven made wages or better. Since 1919, the mill has
not been operated and only a few thousand dollars production has been
reported.
The incomplete records of output since 1896 indicate a gross of
about $3,000,000.
Mammoth (Webster) Mine (later part of the Republican) is on
the east side of Woods Creek, just north of where it enters Tuolumne
River. The development of this claim was done principally by Sierra
Buttes Mining Company in the middle 1890 's. Four crosscut adits
were run, the lowest and longest being 673 ft. long in 1896, and
reported to give a depth of about 500 ft. below the outcrop on the dip.
From near the face of this adit a winze was sunk 430 ft. in the gouge
on the hanging wall of 'bull quartz' vein. The vein was prospected
for a length of 500 ft. or more, but no exact record of the work
remains. As much as 30 ft. in width carried some gold.
A 10-stamp mill was erected and a production of $40,000 was
reported in 1896. The company gave up the property because of the
low grade of vein, after several years' work.
Mazeppa prospect, adjoining the Jumper on the south has a shaft
800 ft. deep sunk on the vein, which is five to 20 ft. wide. The shaft
was sunk in 1900 to over 500 ft. deep at an average cost of $19.65 a ft.,
and over 1100 ft. of drifts, crosscuts and raises were run at an average
cost of $8.25 a foot. On the 400-ft. level a crosscut 202 ft. east is said
to have shown two other veins. There is no record of value of ore.
Since then an interesting surface prospect has been found, showing
gold in decomposed ankerite.
McAlpine Mine is 17 miles from Chinese Camp and 4 miles
from Coulterville. McAlpine Hill, one of the prominent quartz out-
crops of the Mother Lode, is 2200 ft. high. It is stated that in early
days this ground yielded $75,000 net to a depth of 150 ft. It is
reported stoped out to the level of the adit which has its portal close
to the shaft collar. In the McAlpine the lode is 100 ft. wide, contain-
ing large bunches of quartz ; the best pay, however, is reported in the
DAVIS, <
CROSS SECTION J-K-L
PLAN AND SECTIONS
/CALIFORNIAN GENERAL MINING CO.,LTD.
JUMPER MINE
TUOLUMNE CO.,CALIFORNIA
MOTHER LODE GOLD BELT 169
green talcose vein matter near the hanging wall. The property lay
idle a long time until after 1910 when a vertical shaft was sunk
455 ft. with crosscuts at 200 and 375 ft.
McAlpine Mines Company was formed in 1914 and sank the shaft
to a vertical depth of 670 ft., with five levels. Work continued inter-
mittently until 1923 but nothing is known to have been done since.
The company is no longer listed as active. The property has several
buildings, an electric power line, and an old double compressor and
single-drum hoist, each with a 75-h.p. electric motor.
Norwegian Mine, on the north slope of Jackass Hill east of the
Mother Lode, has been worked in a small way ever since 1851. M.
Lawson, the original owner and family were said to have produced
over $80,000 prior to 1897, when it passed to new owners. For six
years thereafter, it was a producer annually, the output in 1897 having
been over $51,000. In 1898, the shaft was 355 ft. deep ; in the 30 years
thereafter it was sunk only about 200 ft. deeper. Since 1911, however,
it has been a small producer nearly every year, with generally one or
two men working under lease.
This mine is at the north end of the Jackass Hill amphibolite
schist area, close to the contact of the Calaveras slate. The Norwegian
vein was first worked to a depth of 190 ft. where a 'horse' was encoun-
tered. At 275 ft. in depth, this vein was reported 12 to 18 inches
wide; at 350 ft. deep a body of rich ore 20 ft. long and six inches
wide was found. In 1898 it was confidently believed it would develop
into a producer of sufficient tonnage to justify 20 stamps, but this hope
has not been realized. The largest tonnage mined in a single year was
398 tons, with a resultant low value of only about $10 a ton. The ore
is almost entirely 'high grade,' characterized by the presence of
petzite and other tellurides, and the sulphides of iron, copper and lead.
The vein worked in later years is the footwall vein, 12 ft. west of the
Norwegian vein and four to six inches wide. The ore zone containing
these veins is an intensely altered band of amphibolite schist about 50
ft. wide. At places the veins have cut bands of slate and the operators
have found these slate intersections favorable for pockets. The schist
is impregnated with pyrite and carbonates, as is common on this hill,
the pyrite content going as high as 10% or more.
Nynian Consolidafed (Santa Ysabel Group) contains five patented
quartz claims, two mill sites and mineral rights on 44 acres of other
land, adjoining the App Mine on the south. It is a consolidation of
the Nyman, Knox & Boyle and Miller & Holmes mines, which were
grouped as the Santa Ysabel about 1896. Previous to that time, the
Knox & Boyle had an inclined shaft sunk 600 ft. from a station cut in
an adit level run from the south. The ]\Iiller & Holmes shaft was 360
ft. deep, and No. 1 (most southerly) shaft was 250 ft. deep at the same
time, in addition to the older work. The Knox & Boyle ore was
crushed in a 10-stamp mill. This mine had been the principal pro-
ducer of the group but there are no definite details of tonnage or
value of output available, either for it or for the other units. From
1897 to 1900, inclusive, the Santa Ysabel produced a total of about
$115,000. Intermittent small-scale operations were carried on from
1908 to 1922 and the grade of ore varied considerably from year to
MOTHER LODE GOLD BELT 169
green talcose vein matter near the hanging wall. The property lay
idle a long time until after 1910 when a vertical shaft was sunk
455 ft. with crosscuts at 200 and 375 ft.
McAlpine ]\Iines Company was formed in 1914 and sank the shaft
to a vertical depth of 670 ft., with five levels. Work continued inter-
mittently until 1923 but nothing is known to have been done since.
The company i.s no longer listed as active. The property has several
buildings, an electric power line, and an old double compressor and
single-drum hoist, each with a 75-h.p. electric motor.
Norwegian Mhie, on the north slope of Jackass Hill east of the
Mother Lode, has been worked in a small way ever since 1851. M.
Lawson, the original owner and family were said to have produced
over $80,000 prior to 1897, when it passed to new owners. For six
years thereafter, it was a producer annually, the output in 1897 having
been over $51,000. In 1898, the shaft was 355 ft. deep ; in the 30 years
thereafter it was sunk only about 200 ft. deeper. Since 1911, however,
it has been a small producer nearly every year, with generally one or
two men working under lease.
This mine is at the north end of the Jackass Hill amphibolite
schist area, close to the contact of the Calaveras slate. The Norwegian
vein was first worked to a depth of 190 ft. where a 'horse' was encoun-
tered. At 275 ft. in depth, this vein was reported 12 to 18 inches
wide; at 350 ft. deep a body of rich ore 20 ft. long and six inches
wide was found. In 1898 it was confidently believed it would develop
into a producer of sufficient tonnage to justify 20 stamps, but this hope
has not been realized. The largest tonnage mined in a single year was
398 tons, with a resultant low value of only about $10 a ton. The ore
is almost entirely 'high grade,' characterized by the presence of
petzite and other tellurides, and the sulphides of iron, copper and lead.
The vein worked in later years is the footwall vein, 12 ft. west of the
Norwegian vein and four to six inches wide. The ore zone containing
these veins is an intensely altered band of amphibolite schist about 50
ft. wide. At places the veins have cut bands of slate and the operators
have found these slate intersections favorable for pockets. The schist
is impregnated with pyrite and carbonates, as is common on this hill,
the pyrite content going as high as 10% or more.
Nyman Consolidated (Santa Ysahel Group) contains five patented
quartz claims, two mill sites and mineral rights on 44 acres of other
land, adjoining the App Mine on the south. It is a consolidation of
the Nyman, Knox & Boyle and Miller & Holmes mines, which were
grouped as the Santa Ysabel about 1896. Previous to that time, the
Knox & Boyle had an inclined shaft sunk 600 ft. from a station cut in
an adit level run from the south. The Miller & Holmes shaft was 360
ft. deep, and No. 1 (most southerly) shaft was 250 ft. deep at the same
time, in addition to the older work. The Knox & Boyle ore was
crushed in a 10-stamp mill. This mine had been the principal pro-
ducer of the group but there are no definite details of tonnage or
value of output available, either for it or for the other units. From
1897 to 1900, inclusive, the Santa Ysabel produced a total of about
$115,000. Intermittent small-scale operations were carried on from
1908 to 1922 and the grade of ore varied considerably from year to
170 TUOLUMNE COUNTY
year, but the bulk of it is reported to have yielded $4 to $6 a ton.
Part of the time the work was done by lessees.
The claims are on Quartz Mountain, one of the large prominences
on the Mother Lode caused by a wide outcrop of quartz and ankerite.
The Knox & Boyle is on the east side of the 'mountain,' where a
'feeder' vein enters the lode from the northeast. The 'bull quartz'
vein is as much as 150 ft. wide on these claims, and there is an abundant
development of mariposite. Ore may be found in the East and West
veins (so called because of their positions relative to the 'bull quartz'
vein) and in the 'feeder' vein mentioned which is called the Knox &
Boyle. The country rocks are amphibolite schist to the east and Cala-
veras slates on the west. The hanging wall of the East vein is reported
to be an altered diorite dike, and the footwall mixed slate and schist
but the mine has been closed every time a field trip has been made to
the district, and no inspection could be made underground.
The ore-shoot opened by the Knox & Bo^de 800-ft. inclined shaft
is reported to have been continuous from the surface to the bottom
of the shaft. It is said to have been about 100 ft. long by two or three
ft. thick. It was worked down to the 800-ft. level. The Mascot or
Central orebody was found about 200 ft. north of the No. one 850-ft.
vertical shaft (on Miller & Holmes Mine) and mined from the 400-ft.
level nearly to the surface. This also is reported to have been about
100 ft. long and 4 to 9 ft. thick, but was e^adently lower grade
than the first named.
Another shaft, on an incline of 60° and with three compartments
was later sunk to a depth of 800 ft. at a point about 200 ft. north of
No. 1 shaft. All or nearly all of a working capital of $150,000 was
spent in sinking this shaft and running the drifts and crosscuts on the
400- and 600-ft. levels, with only a little production.
Nyman Consolidated Mines Company was incorporated in 1916
with a capital of $200,000 of which 16l",586 shares of $1 par value
were issued. They worked the property until 1918. Some good ore
was stoped on the Knox & Boyle vein, but the average yield, over $6 a
ton, was reported to have been a little less than operating cost. The
last work was done in 1925 and 1926. This was reported unimportant
by the company. Since then all equipment has been removed.
Patterson Mine, in the Tuttletown area of amphibolite schist east
of the main Mother Lode, has been worked at intervals since 1858. In
1868 it was reported that the pay had been "good for 75 ft. from the
surface but not so good below the water level." Like all the mines of
Jackass Hill and the Tuttletown area, it is characterized by mineralized
amphibolite schist containing a high percentage of pyrite, some of it
in coarse cubes. Gold occurs at times within these cubes or as a thin
film on their surfaces. The workings appear to have reached only
shallow depth until later years, in spite of the fact that the property
had several stamp mills. Previous to 1908, available ore had been
stoped for a length of 500 ft. and an inclined depth of 450 ft., although
the shaft was 800 ft. deep on 65° incline. There is no authentic record
of the production during that period.
In 1920 the mine was reopened and equipped with a good plant,
including good air compressors at north and south shafts, a mill of
twenty 1200-lb. stamps, electric power and hoist. Work was done upon
MOTHER LODE GOLD BELT 171
both the Patterson and Lennon veins which are parallel. Such pay
as was found occurred in stringer leads intersecting the Patterson
fissure, which varied from 1 ft. to 12 ft. wide, strikes N. 65° W. and
dips 65° NE. The Patterson vein was prospected over a total length
(not continuously) of 2200 ft. The 160-ft., 260-ft., 400-ft. and 600-ft.
levels were opened on this vein. On the 400-ft. level, about 1000 ft.
was opened in length, including 485 ft. of new north drift from the
north shaft. The Lennon vein was reached from the Patterson 200-ft.
level by a crosscut of 145 ft. A depth of 385 ft. on the dip was reached
on this vein, with a short drift on the 400-ft. level. From the 6th level
crosscuts were run from the south drift and connection made with the
south shaft.
Although the operators claimed some ore had been found, they
suspended work early in 1922 after crushing a small tonnage of $3
rock. This carried a little less than 2% sulphide containing $23 a ton.
Only a little dump material and picked ore has since been milled by
lessees.
Rappahannock claim adjoins the Rawhide Mine on the north. The
prospecting of this claim was stimulated by the successful operation of
the Rawhide. An inclined shaft was sunk 1150 ft. in the serpentina
of the footwall, and crosscuts were run to the vein on the 100-, 350-,
600-, and 1100-ft. levels. Drifts varying in total length from 250 ft.
to 700 ft. were run on these levels, on a fissure said to have an average
width of 10 ft. No ore-shoots were developed, although some prospects
were reported and a heavy gouge was encountered. Some old buildings
and a steam hoist remain.
Rawhide Mine, two miles northwest of Jamestown, is one of the
important Mother Lode producers for which the owners state no
detailed record is available and, due to the secretive policy of the
operators during the principal period of production, the contemporary
reports lack all the most interesting and valuable details of operation
and results.
In 1867, this mine had a shaft 280 ft. deep, and a drift 80 ft. long
had been run, showing a reported width of 12 ft. of ore ranging in
value from $7 to $44 a ton. Malachite and 'argentiferous gray cop-
per' were mentioned as occurring in the ore. Apparently little was
done at the mine thereafter until 1891, when $38,646 production was
reported. Heavy production began in 1894, but no details of output
were revealed from then on. Estimates made at the time place the
annual production at from $300,000 to $500,000, but F. C. Cullers, who
was mill foreman at the property during the period of principal out-
put, has estimated the total production at $6,000,000. Production
continued until 1905 when an inclined depth of 1845 ft. was reached.
The heavy 'bull quartz' vein, which has the characteristic out-
crop of a rough skeleton of quartz, stained by iron oxide from the
weathering of the ankeritic portions, occurs between serpentine on the
footwall and Calaveras (Carboniferous) formation on the hanging
wall. It is as much as 70 ft. wide.
According to J. T. Lane, the ore was on the hanging wall side of
this 'bull quartz' vein to a depth of 500 ft. where the ankerite cut
out, having a rough wedge shape, with the edge down. From there
172
TUOLUMNE COUNTY
down the footwall was serpentine, which was rotten to a depth of two
ft., and the hanging wall was black slate with heavy blue gouge. In
places a thin layer of 'gray slate' was found between the vein and
the black slate. The ore alternated with poor zones. In the earlier
operations the gouge was left but later superintendents milled it as
it carried as much as $2.50 a ton in gold. Lane states the ore-shoot
varied in width from an average of 5 ft. to a maximum of 12 ft. and
was about 150 ft. long. In the upper part of the mine the ore pitched
south and for a time it was believed that it would pass under the Raw-
hide No. 2 claim, which has its north end-line only about 150 ft. from
the Rawhide shaft but at 800 ft. in depth, the pitch changed to
north. The greatest distance drifted north was about 1000 ft. Below
the 1800-ft. level a winze was sunk 45 ft.
Mill of Senator Mining Co., at Quartz Mountain, Tuolumne County.
Table Mountain skyline in background.
Photo by Walter W. Bradley.
The only work in late years has been the search for 'pockets' in
shallow shafts north of the North shaft and between the Rawhide vein
and the footwall serpentine. Here, two systems of stringers intersect
and some 'pockets' have been found in the zone of intersection.
Senator Mining Company is working on what they state is the
footwall vein on the Hitchcock claim, on the west side of Quartz Moun-
tain and south of the App Mine. The ore-shoot was reported about
worked out on the 100-ft. level in June, 1934. Work was going on at
the 150-ft. level, where it was stated ore had been opened for 80 ft.
on each side of the shaft. Six men, all interested as stockholdei's, were
working the property. A single-drum hoist with 35-h.p. motor and a
compressor with 50-h.p. motor are the principal items of the mine
MOTHER LODE GOLD BELT 173
plant. A mill of 10 stamps with a capacity of 40 to 50 tons crushes
ore which is treated by flotation and concentration. (See flow sheet
No. 10 under Metallurgy.) Dan Williams, superintendent.
Tarantula Mime (not to be confused with one of the same name
northwest of the Rawhide) adjoins the Eagle-Shawmut on the north
and is three miles southeast of Chinese Camp. It was worked only
irregularly and in a small way until 1909, when a French company
put a good plant, including 20 heavy stamps, on the property and then
proceeded to prospect it. A crosscut adit was run 1200 ft. cutting a
sulphide zone in the silicified schist at a depth of 400 ft. From this
an internal shaft was sunk 640 ft. on 70° incline, and levels were
turned every 100 ft. with short drifts. The adit, started from the
southwest part of the Tarantula West Extension claim, crossing it and
the Tarantula claim on the east. Nothing except low-grade altered
schist mineralized with pyrite was found, so far as can be learned. A
little of this was milled and the property has been idle ever since,
though several times included in groups on which promotions have
been based.
Wise Claim adjoins the Chileno on Jackass Hill. It is developed
by two adits, which were 100 and 600 ft. long respectively in 1928. S.
J. Davey, one of the owners, put up a mill of three 600-lb. stamps in
1927, which crushes two tons in eight hours through 40-mesh screen.
It is operated by an old automobile engine.
Ore occurs in stringers in amphibolite schist, and 'pockets' are said
to be found where vertical stringers and a system of others with flatter
dip intersect.
174
TUOLUMNE COUNTY
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180 MARIPOSA COUNTY
MARIPOSA COUNTY
Foreword
The mines in this county have never been in the district assigned
to the Sacramento office of the Division of Mines, so that the writer's
opportunities to visit them have been limited. In addition to this, few
of the Mother Lode mines there have been active in the last 20 years,
until the present revival in gold fiaining. Mariposa County has many
mines besides those on the Mother Lode, and in late years these others
have been producing most of the gold credited to the county. Much
of the material herein on Mariposa County except in the few cases
where the mines have lately become accessible for inspection, is there-
fore a compilation of information from the most reliable sources
available.
History — The Fremont Grant
Besides the conditions which have adversely affected gold mining
everywhere since 1916 and until recently, the progress of mining in
Mariposa County has been hampered since earlj^ days by the fact
that some 14 miles in length out of a total of 25 miles on the Mother
liode has been under one ownership since 1856. The Fremont Grant,
"Las Mariposas," containing 44,387 acres, was purchased from its
Mexican owner in 1847 by Colonel John C. Fremont. As was usual
with such grants, its boundaries had not been definitely established.
Soon after the discovery of gold at Coloma in 1848, mining claims
were taken up along the Mother Lode in Mariposa County, and mining
started. When Fremont finally established his lines he swung them
around so as to include the best section of the lode, which had for some
time been in the possession of miners. There was then no U. S. min-
ing law applying to California land under which miners could obtain
patents. They were holding the claims under the local miners' rules
and customs, which everywhere else in the State had public sanction
and the force of law. In turn, the miners contended, and with good
reason, that the Mexican law under which the grant had been made,
and which was derived from Spanish law, was based on the severance
of mining and surface rights and that the grant was only of the latter.
After lengthy disputes and some bloodshed, the miners were dis-
possessed following a court decision in 1859 that the U. S. patent
issued to Fremont in 1856 carried the mineral rights. This grant
extends from the Merced River opposite Bagby (formerly Benton
Mills) to a line 2| miles south of Mariposa. The most noted of the
mines were the Josephine, Pine Tree, Princeton and Mariposa besides
which many smaller ones have been productive. Under the Fremont
ownership, important production began in 1860 and by May, 1863,
had reached $101,000 a month. It was not long thereafter that the
grant became the subject of one promotion scheme after another, and
comparatively little gold was produced (considering the possibilities)
until 1900, when a period of activity started. This ended in 1915 and
MOTHER LODE GOLD BELT 181
the mines of the grant have since been idle until Pacific Mining Com-
pany took a lease on the northern section of it in 1933. Now the
prospect is that the Pine Tree, Josephine and adjoining mines may at
last fulfill the hopes so long held for them.
Next to the Fremont Grant, the largest land holder in the mining
section was the Cook Estate, at one time controlling some 20,000 acres,
including most of the mines on the lode in the Coulterville district.
The Merced Gold Mining Company took over these holdings about
1895 and worked the Mary Harrison, Louisa, Malvina, Potosi and
other claims. Outside of these two large properties, the development
of mines on the Mother Lode has been limited to shallow depths so
far, the deepest being the Virginia, reaching about 1300 ft.
Geology
This most southerly of the Mother Lode counties shows geologic
characteristics similar to those noted in the northerly counties, but
like El Dorado, its Mother Lode mines have not been developed much
below 1000 ft. in depth. The lode enters the county from the north
in the serpentine which flanks the Mariposa clay slates on the east
and which extends for 3| miles from the county-line nearly to Coulter-
ville. The Peiion Blanco and Champion Mines are in that section.
Near that town, where the serpentine pinches, the Louisa Mine lies at
the eastern contact of slate and greenstone. At the western contact
lie the Tj-ro, Potosi and Malvina. Two miles south of the town the
serpentine outcrops again at the easterly contact of the Mariposa
slate, separating it from the Calaveras beds. Here the Mary Harrison
mine was quite extensively worked. The Virginia, another good pro-
ducer is three miles south of Coulterville at the eastern contact of
serpentine and Calaveras (Carboniferous) slate. From there south
to Bagby the serpentine increases to a mile and a half in width and
the Mariposa slates maintain a width of a mile. This section has
so far had no large mines, but many pocket producers. Overlooking
the river north of Bagby a group of claims have been worked in a
limited way, showing more sulphide than is usual on the lode.
South of Merced River on the Fremont Grant, the serpentine
pinches down to a long narrow dike along the east boundary of the
Mariposa slate, the veins of the lode increase in number and the best
mines occur. The Josephine and Pine Tree veins are close to the
slate-serpentine contact, the former being in slate and the latter in
the contact zone in the present workings. Near Bear Valley, however,
Ihe serpentine leaves the slate and fingers out in the hanging-wall
greenstone. From there south the mines are in the slate. The great
number of veins within the boundaries of Fremont Grant may be
realized when it is remembered that the owners have a record of
production from 73 different openings from nearly as many veins. (See
tabulation.)
The southern termination of the Mother Lode is generally placed
near the old town of Bridgeport about four miles south of Mariposa
and near the south boundary of Fremont Grant. "While the Jurassic
slate extends from there nearly 30 miles into Madera County, it is
separated into two bands one lying on each side of an immense mass
182
MARIPOSA COUNTY
of granitic rock forming a part of the Sierra Nevada batholith. No
important mines occur in these sections.
As in the other counties where the Mother Lode is associated
with serpentine, immense outcrops of 'bull quartz' (silica, dolomite
and ankerite) are found at several places. Penon Blanco near the
north county-line, and the May Rock near Bear Valley are the most
remarkable, the latter being 82 ft. high. These great lenses reach
a width of as much as 300 ft. and are similar to the masses farther
north in Tuolumne County at Quartz Mountain, Shawmut and
Whiskey Hill. As in those localities, such ore as may occur is not in
the great vein itself but in veins on either side of it.
Geography, Climate, Water, Power, Timber
Topographically, Mariposa County is similar to all of the other
counties of the Mother Lode in its western portion. The Mother Lode
crosses a series of interstream ridges separated by the canyons of
streams which dissect the lower slopes of the Sierra Nevada as they flow
toward San Joaquin Valley on the west. This section lacks the pleas-
ing, park-like aspect of the lode in other counties, although farther
to the east the typical Sierra Nevada growths of conifers are found.
The county had a population of 2530 in 1930, or an average of less than
two people to each square mile. Stock-raising and mining are the
principal industries.
Gold and Silver Production of Mariposa County, 1880-1933
Year
1880.
1881.
1882.
1883.
1884
1885.
1886.
1887.
1888
1889.
1890.
1891.
1892
1893,
1894
1895
1896.
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
Gold,
value
$150,017
200,000
250,000
220,000
180,000
149,177
197,600
187,165
175,000
145,819
124,265
84,414
81,011
164,116
153,708
216,622
335,637
451,427
336,418
562,829
157,663
504,928
631,478
542,355
429,771
386,380
366,394
405,498
Silver,
value
$1,300
1,200
4,000
3,000
100
250
210
22
67
307
39
7
180
660
993
2,207
13,853
4,787
3,880
3,353
2,839
5,231
3,377
4,500
Year
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919 _
1920 _
1921
1922
1923
1924
1925
1926
1927
1928 -_
9129
1930
1931
1932
1933
Total values
Gold,
value
$439,862
396,465
317,580
172,532
160,541
171,034
131,458
385,577
401,718
313,296
337,682
253,392
261,830
331,295
218,571
141,883
182,099
192,810
182,313
183,805
120,568
91,052
58,985
88,600
169,627
254,663
$13,748,930
Silver,
value
$4,732
2,729
2,364
1,390
6,796
7,430
677
2,175
2,680
3,221
5,083
4,139
4,705
5,251
3,301
1,735
1,608
1,758
1,518
1,376
2,199
651
318
551
636
1,112
$126,593
The treeless aspect of long stretches of the lode here is due largely
to the extensive outcrops of serpentine and related rocks, and not
to aridity, although there is a decrease in rainfall going south. The
mean annual rainfall at Jacksonville, elevation 650 ft. and only a few
miles north of the Mariposa County line on the lode, was 27.04 inches I
MOTHER LODE GOLD BELT 183
over a 10-year period. At Mariposa, elevation 1932 ft. and on the
Mother Lode near its southern end, the annual average precipitation
over a period of 14 years Avas 30.72 inches. As elsewhere on this
mineral belt, snow is a rarity and the summers are warm and almost
completely devoid of rain.
The county supplies water to the city of San Francisco but has
less in its western sections for local use than might be desired. The
present lessee of the principal mines on the Fremont Grant is pumping
water 1200 ft. vertically from Merced River for milling ore at a cost
per ton of ore milled which is not excessive. Many other claims might
be similarly supplied. Electric power is now available on or within
a short distance of most of the Mother Lode. Timber is available from
the region east of the lode, as in the nearby counties.
Champion Mine is on Blacks Creek a mile and a half northwest
of Coulterville. From time to time, small tonnages of rich ore and
pocket rock have been milled by lessees from this claim. No particu-
larly rich rock has been reported as coming from the claim since 1911.
In 1914 and 1918, a few hundred tons of medium to low-grade ore
was milled. The vein is reported 6 to 12 ft. wide. There are two
inclined shafts, one 200 ft. and the other 250 ft. deep, between which
ore has been stoped.
Louisa Mine is on IMaxwell Creek where the Mother Lode crosses
it just south of Coulterville. The lode here, lying on the east side
of the Mariposa slate, has a width of 300 ft. of the dolomitic rock or
ankerite, colored in places hy mariposite and everywhere interlaced
by quartz stringers. Large quartz veins and lenses occur. One lens
is about 300 ft. long and 20 ft. wide, but a shaft sunk on its footwall
showed it thinning out. A vein 10 ft. to 20 ft. wide lies in the center
of the lode, and a cross vein forms junctions with the lenses and veins
running parallel to the lode. Greenstone forms the hanging wall
and a strip or dike of similar rock lies between the ankerite lode and
the Mariposa slate on the footwall.
There is a vertical shaft 375 ft. deep, with 275 ft. of drifting on
the 100-ft. level, 75 ft. on 200-ft. level and 500 ft. of drifting on the
300 ft. level. There are also said to be crosscuts totaling 775 ft. and
winzes totaling 600 ft. as well as an air shaft 150 ft. deep. This work
was done by Merced Gold Mining Company, 1895 to 1900 and ore was
taken to the Potosi mill. There are no separate figures at hand for the
production of the Louisa.
MalvvtKi Group is a mile west of Coulterville in Sec. 4, T. 3 S.,
R. 16 E. on the west side of the Mariposa slate. These claims were
located in 1852. By 1867, Malvina No. 1 claim had been opened to a
depth of 440 ft. by an adit and the lode had been followed 330 ft.
It is stated that 3000 tons of ore mined above this level yielded an
average of $7 a ton, and that the average width of the vein was 10 ft.
There is a strip of greenstone on the hanging-wall side interbedded
with the iMariposa slate, which forms the footwall. The Potosi mine is
on the north and the Tyro on the south. These claims formerly were
part of the holdings of the Cook Estate, at one time the second largest
landowner in the county. In 1895 all their mines passed into the
184 MARIPOSA COUNTY
hands of Merced Gold Mining Company and ore from the dijfferent
workings was crushed in a mill on the Potosi.
The results of two years' work by this company on the Malvina
were reported to be disappointing. In August, 1897, they removed
the machinery and the claims have lain idle ever since until early in
1934, when plans for reopening were announced.
The work done by the former operators includes a 3-compartment
vertical shaft sunk in the hanging-wall slates to a depth of 1000 ft.
with levels at 200, 400, 600, 900 and 1000 ft. A total of 2287 ft. of
drifts are reported, with some drifting on all but the bottom level.
There was also an incline 875 ft. deep and a tunnel about 3000 ft.
long for hauling ore to the Potosi fnill.
Mariposa Mine at the south side of Mariposa was discovered in
the spring of 1849 by Kit Carson, the famous scout, and two associates.
In July of that year. Palmer, Cook & Company were running a stamp
mill on ore from this mine. This was possibly the first stamp mill in
the State; but it was not complete, as the pulp after stamping had to
be washed in rockers to save the gold. It was one of the best known
of the gold quartz mines of early days and had a reported production
of $200,000 before Fremont succeeded in ousting the original owners
when his title to the mineral rights on the grant was confirmed in
1859. Thereafter, it was operated under lease by Barnett until 1864.
He sorted the ore, and made a success of the mine. In 1864, it was
worked by the stock company that had taken over the grant, and
although the ore was claimed to average $25 a ton, no profit was
reported from a gross yield of $84,948 that year. Soon after, the grade
of ore fell off to $10 or $11 a ton and the mine was closed in October,
1870, after three months milling with 25 stamps gave an average of
$9.98 a ton, scarcely enough, it was stated, to pay expenses. Up
to that time, it was claimed to have had an output of $1,500,000 to a
depth of 275 ft. and had had five mills.
In 1898, when control of the grant changed hands, this was one
of the mines reopened. In sinking the new inclined shaft, it was
found the vein passed into the hanging-wall greenstone at about
400 ft. depth. Some good ore was found to have been left on the
275-ft. level in the old workings because it was apparently too hard
for hand drilling. Between December 20, 1900, and the end of 1915,
the mine produced 112,379 tons which yielded $693,205. Work reached
a depth of 1550 ft.
If the old reports, particularly that of J. Ross Browne for 1868,
are accurate, the Mariposa outcrop was extremely rich, as attested
by the extensive placer work below it. The vein, which strikes N. 70°
W. splits near the old shaft, with a fork going N. 50° W. These
branches are said to have contained rich gold pockets, and were
worked in the early days in the usual manner of ' pocket ' mines. Accord-
ing to a contemporary report, "They have not been worked upon
any regular system, but have been much burrowed into by different
parties in quest of these rich pockets." The main vein southeast of
the split was evidently of more uniform gold content. It was here,
some distance southeast of the old shaft, that the new one was sunk.
It had eight levels with drifts as follows :
MOTHER LODE GOLD BELT 185
Level Depths
East Drift
West Dri:
(inclined) Feet
Feet
Feet
275
390
400
475
400
637
625
700
600
800
322
410
970
396
412
1200
250
400
1400
60
50
1550
200
130
Ore is reported stoped out aboTe the 800 ft. level. The walls are
greenstone (diorite porphyrite), and the vein is said to vary in width
from a seam to 12 ft. The tabulation of production herewith shows
the best year's results were had in 1901, when 21,557 tons averaged
$10.25 a ton recovery. In the lower half of the mine (so far as opened)
assay values dropped quite low.
Mary Harrison Mine is two miles south of Coulterville on the east-
ern part of the Mother Lode near the contact of the Mariposa slate and
serpentine. Previous to 1867 it had been opened by an incline 240 ft.
long and an ore-shoot reported 200 ft. long had been stoped to an
inclined depth of 150 ft. When this mine, with the others of the
Cook Estate, passed to Merced Gold Mining Company in 1895, it had
an inclined shaft 400 ft. deep. It became the most important of the
company's mines. Ore was opened on the 400-ft. level for a reported
length of 300 ft. While this was being mined a new vertical shaft was
driven some 750 ft. from the old shaft. The attempt to mine through
the old shaft and transfer ore for hoisting through the new one made
operations expensive and slow, and the output per man appears to have
been only a little over 1 ton per shift. The vertical shaft finally
reached a depth of 1200 ft. and the incline of 800 ft. Levels were
opened at 100-ft. intervals and some 5000 ft. of drifts were driven.
Operation ceased about 1903, and all surface plant has been removed
or burned.
The principal vein in this mine was on the footwall side of the
dolomitic complex common along the lode near serpentine; Storms
called both walls ''diabase," but dumps and outcrops show the char-
acteristic mariposite-stained ankerite. Old company reports released
at the time of operations, and giving about the only information
available locally, indicate an ore-shoot 300 ft. long from the 400-ft. to
700-ft. level. It was reported 10 ft. wide in the upper part, decreasing
to about 3 ft. on the 600-ft. level, and giving there and on the 700-ft.
level very erratic assays, with some ri^h ore, but mill returns in 1897
were about $5 a ton. The mine was represented then as containing
about 60,000 tons of ore that would pay a profit of about $1 a ton.
The record of production is not complete but from 1898 to 1903, inclu-
sive, the yield was evidently between $330,000 and $400,000.
Penon Blanco Mine was the first claim in the county for which
patent was sought under the mining law of 1866, which did not limit
the length of claims. As a result, this claim is 5850 ft. long. North
Peiion Blanco claim on the north, and Old Judge and South Judge
claims on the south, give the group a total length of nearly two miles
186 MARIPOSA COUNTY
on the lode, beginning close to the Tuolumne County line. The claims
are along the large lens of serpentine which traverses the lode in
this region, and which, a little farther north, has entirely displaced
the Mariposa slate.
Peiion Blanco is one of those prominent ridges of quartz and dolo-
mitic rock common in such sections. At the south end of Peiion
Blanco claim the lode formation is 250 to 300 ft. wide, and composed
of this dolomitic rock traversed by numerous quartz stringers. Lenses
or veins of massive quartz of all sizes occur in this formation. In this
claim, such a quartz vein occurs on the east side of the lode. Only a
little work was done on the mine in early days, and no record of out-
put, if any, remains. Some 34 years ago, Oro Rico Mines Company
was organized and began work. The vein was reached through a
crosscut 600 ft. long, giving a depth of 320 ft. below the outcrop, and
1000 ft. or more of drifts are reported as having been run on the
vein. A winze was sunk 350 ft. deep from the floor of the west drift,
and four levels were turned, but the amount of work done on these is
unknown. The company worked until 1912 or 1913, since when the
property has been tied up by litigation and disputes. Vein is reported
3 to 7 ft. wide.
A 20-stamp mill was built by this company but only a little ore
was milled before closing.
Pine Tree and Josephine Mines are on the Mariposa Grant and
are the principal mines in the grant holdings under lease to Pacific
Mining Company which extend from the Merced River at Bagby to
the north line of T. 5 S., R. 17 E., along the Mother Lode. The
River Tunnel and Queen Specimen Mines, less noted than the above,
are also included.
The Pine Tree and Josephine were among the earliest mines
worked on the Mother Lode and their romantic histories have often
been alluded to in past reports. Although J. Ross Browne, Special
U. S. Commissioner for collection of mining statistics, stated in 1866
that these two mines had then been worked for nearly 16 j^ears, he
was unable to give any details of production before 1860, other than
to say that the gross production had been, undoubtedly, very large.
Through the decision of the courts in 1859, fully confirming the title
of John C. Fremont to the grant "Las Mariposas, " including mineral
rights, these mines passed from the hands of previous operators and
work was begun by the Fremont interests. From June, 1860, to May,
1863, the output of the Pine Tree and Josephine was $350,000 from
45,000 tons of ore. In 1864, the Pine Tree yielded $67,940 according
to Browne and the Josephine lay idle, having been temporarily aban-
doned because the ore did not pay $8 a ton in the Benton mill, which
was known to be a very poor gold saver. Experiments with new
methods of milling were carried on for some time thereafter. The
production record is fragmentary; for the fiscal year 1869-1870, the
production of the Josephine, Pine Tree and Mariposa mines was about
$170,000. The Fremont Grant property had become the subject of
stock-selling schemes, debts had piled up and one company succeeded
another for several years. During this time, considerable work appears
to have been done, including the starting of the River Tunnel from
near the level of Merced River and running southward. It finallj'-
MOTHER LODE GOLD BELT 187
reached a length of 3300 ft. with its face under the Queen Specimen
and a depth of 1200 ft. below the present workings. There were also
numerous shorter adits driven at higher elevations.
In 1887, the Mariposa Commercial & Mining Company was formed
by Hayward, Hobart, Mackay, Flood and associates and took over
the title which had been purchased by Donahue at sheriff's sale. From
1888 to 1898. inclusive, only about $10,000 is recorded as coming
from the mines on the grant. In 1898 there was a change in stock
ownership and British capital was supplied for reopening the mines
under the management of John H. Mackenzie. The itemized tabula-
tion of production of the mines on the Fremont Grant (see, post)
from 1900 to October 31, 1915, shows that the Pine Tree and Josephine
produced during that period 20,968 tons which yielded $371,748 giving
an average recovery of $12.40 a ton. Since 1915, the combined pro-
duction of the mines on the grant has been small, usually amounting
to only a few thousand dollars a year from the scattered operations of
lessees, until the north end of the grant was taken over in 1933 by
Pacific Mining Company.
Mine Workings
The work of this company has been principally sampling and
developing the large blocks of low-grade ore in the Pine Tree-Josephine
area particularly. A mill with a daily capacity of about 100 tons has
been built and milling has been going on steadily during the past two
years. A total of 2300 ft. along the strike has been sampled through
the following old adits, which had been driven by previous operators
and are in the order named, north to south : Jacinto, December, April,
September, English Trail and 7 others which cross the lode at
vertical depths of from 75 to 300 ft. below the surface. The New Pine
Tree Tunnel, from which hundreds of samples have been taken and
many thousand tons of ore already milled, is north of those named
and about 224 ft. vertically below them. It was 1200 ft. long in June,
1934, and had then to be driven about 1200 ft. farther south to con-
nect with No. 1 crosscut workings connecting wdth an old adit 560 ft.
long on the Josephine vein from the September adit. The deepest new
w^ork is a winze being sunk from the New Pine Tree Tunnel on the
Pine Tree vein, and this was 433 ft. deep or 783 ft. below the outcrop in
June. In the work directed by Mackenzie about 1900 a winze was sunk
to a depth of 500 ft. on the Josephine vein below the floor of the Eng-
lish Trail adit. He ran the 300-ft. level from this 350 ft. south and 240
ft. north. This showed material similar in average grade to much of
that sampled in the blocks above. It can be entered through the New
Pine Tree Tunnel workings.
The work being done is for the purpose of testing the possibilities
of the property and the character of ores and their amenability to
treatment, with a view of initiating operations on a large scale if results
are satisfactory. At the time of visit in June the work appeared to be
moving successfully. Over 30,000 tons of ore had been milled, the
larger part coming from the Pine Tree vein in the Josephine mine.
The hanging-wall Pine Tree vein and Josephine vein had also given
good results with higher gold content than the average obtained. If
the work is carried through according to present tentative plans, Mari-
188
MARIPOSA COUNTY
posa County will have one of the largest operations on the Mother
Lode, under the direction of a capable and well-financed company.
Mining by block-caving after stripping with a power shovel is con-
templated.
Geology
The sketch showing a cross-section of the veins in the New Pine
Tunnel at crosscuts No. 2 East and No. 3 West gives an idea of the
conditions found in the sections sampled. Much has been written in
the past about the geology of the two mines which were formerly
worked separately. The two veins are separated by a varying width
of the complex mixture so familiar on the lode in the vicinity of
serpentine — ankerite, quartz, mariposite and remnants of igneous
rocks showing flow structure in places. In the section shown, this
complex is 60 ft. wide. The present operators call it the Inter vein.
Section across veins in New Pine Tree Tunnel, looking north, near crosscuts No. 2
East and No. 3 West.
The total width of the lode here from the black Mariposa slate foot-
wall to the greenstone hanging wall is 125 ft. The Josephine vein
is a typical one of stringers and lenses of quartz in the black slate,
and is here 18 ft. wide. The black-slate footwall dips 55° east. The
Inter vein forms the hanging wall of the Josephine vein in the work-
ings visited ; in other parts of the property it varies greatly in width.
The old Pine Tree vein, from which the earlier operators produced
good ore, lies on the immediate hanging wall of the Inter vein. The
old work on this vein is reported to have reached a depth of 500 ft.
on the dip, and a length of 500 ft. on the strike is said to have been
stoped. Its immediate hanging wall is a 'bull quartz' vein 12 ft. thick.
Then comes the hanging-wall Pine Tree vein, 8 ft. to 14 ft. wide, said to
be a new development from which ore recently milled has yielded
very well. On this, and separating it from the greenstone of the main
hanging wall is a layer of serpentine and talc schist of varying thick-
ness, here 10 ft.
OAV,S,CM.FOBN>»«»»
Proifuelion
Of Min.
on the Fremon
Grant, Ma
iposa Co
nty, 1900
lo October SI, 191
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PHYSICAL SCIENCES UBRAAY
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DAVIS, CAUFORNW W(1«
PHYSICAL SCIENCES UBHAflt
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MOTHER LODE GOLD BELT 189
In the River Tunnel 1200 ft. below the level of the New Pine Tree
Tunnel, it is stated by the operators that the Josephine vein appears
but that the Pine Tree vein is not to be seen. Storms in 1900 men-
tioned that the Pine Tree and Josephine veins were close together in
the Josephine Mine on the level of the English Trail drift "about
400 ft. north of the point of meeting on the croppings" and "are sepa-
rated by a mere seam no thicker than a knife blade." He also men-
tioned the divergence of the veins going northward from there. The
occurrence of erythrite (cobalt bloom) was reported by H. W. Turner,
and danaite (a cobalt-bearing arsenopyrite) was reported by the
State ]\Iining Bureau 40 years ago in talc schist between the Josephine
and Pine Tree veins.
Although the work is in the nature of prospecting and develop-
ment in large part, preparatory to operation on a bigger scale by other
methods, it may be noted that a total crew of 36 men were mining
and milling lOi tons of ore daily in June, 1934, or nearly 3 tons per
man-shift, with part of the crew engaged in sinking. Favorable and
creditable costs for mining, development and milling were being
achieved, and an operating profit was being made on ore yielding from
0.2 to 0.3 ounce of gold per ton.
Princeton Mine at I\It. Bullion has probably been the largest gold
producer in the county. It is said to have been opened in 1852, and
was credited for a time with being the heaviest producer in the State,
yielding $90,000 a month. The ore yielded up to $70 a ton within
100 ft. of the surface. By 1867 it had been opened to an inclined depth
of 560 ft. (200 ft. vertical) and had been opened on the strike for
1200 ft. J. Ross Browne in that year recorded the following figures of
production :
Tons Value
.January. lSr.9. to June 1. 1860 2.000 .$36,000
.Tune 1. 1860. to Nov. 1, 1860 23.916 527.633
In 1862 and 1863 121.000 2,000.000
In 1804 243,707
The total production up to 1867 was reported over $3,000,000.
After 1864, when the Princeton was regarded as bottomed, and the
Fremont Grant was in financial difficulties, a creditor took out the
pillars and other ore in sight, dumped waste in the shaft, and left the
mine in such bad shape no one wished to reopen it.
When the mines on the Fremont Grant came under the control
of a British firm about 1899, the Princeton was reopened by a new
inclined shaft. It was found the old company had indeed struck a
lean zone at 600 ft. and the best ore left assayed only $2 a ton. The
new operators, under the management of John H. Mackenzie, sank
deeper and found "long and wide bodies of good ore — $5 and $4.50 a
ton, between 600 and 1000 ft. levels," according to Mackenzie. Soon
after, the Princeton resumed its position as the best producer in the
county, yielding $1,228,273.56 from 350,329 tons of ore between 1900
and 1915, nearlv all prior to 1911. Since then, little has been done.
The shaft had reached a length of 1660 ft. with 8 levels, 11,418 ft.
of drifts and 3127 ft. of crosscuts and raises. The vein was reported
to average 8 ft. wide, in Mariposa slate and dipped 45^^ to 60° NE.
Ore was stoped out as far down as the 1200-ft. level.
190 MARIPOSA COUNTY
Tyro Mine, south of the Malvina, on the west side of the Mother
Lode, was productive principally in the period 1893 to 1897, although
it had been worked previously. The production is estimated to have
been over $110,000 during a period of four years when a 10-stamp mill
was operated.
The vein has Mariposa slate walls and is reported 2 to 7 ft. wide
in different parts of the workings, with gouge on both walls. It
carried finely divided gold and the sulphide content was reported to
be 3%, consisting of iron and copper sulphides, including some covellite.
The last shaft was sunk 700 ft. by 1896, and had six levels with
only 1870 ft. of drifts reported. An orebody is said to have been
stoped for a length of 80 ft. down to the 700-ft. level. There is an
old shaft connected by air passages with the later work. There is no
record of work after 1897.
Virginia Mine, 4 miles south of Coulterville, was one of the first
claims patented in the county. It has been a frequent but not regular
producer and has been worked on a small scale, with a creditable total
output from a small tonnage of ore. There are five patented and one
unpatented claims.
The vein generally ranges from 8 inches to 4 ft. wide, though at
times larger. The hanging wall is greenstone at the south and Cala-
veras formation on the north and footwall serpentine. The ore varies
a great deal in gold content, from low-grade milling ore to 'specimen
quartz,' as is common with veins associated with serpentine. The
mine has been worked in a hand-to-mouth manner, passing from one
stock company or operator to another. The plant is small and build-
ings, though numerous, are old. The total production from 1898 to
1931, inclusive, has been over $660,000 from ore that has averaged
over $10 a ton. In 1932 it was claimed that mining and milling cost
$9 a ton.
At that time a raise was being put up from the 1300-ft. to 1200-ft.
level and a drift was being run in ore on the former level. The shaft
is an incline on the vein. The work in 1932 was in search of the north
shoot, which had been of good width and grade on the 1200-ft. level,
but quite short. The south shoot extended down to the 700-ft. level,
where it was said to shorten to 20 ft. in length, and had not been
found below there, so that ore so far as known was mined out to the
1200-ft. level.
The larger and more productive part of the work was done by the
Procter & Gamble interests between 1915 and 1922 and from the
400-ft. level to 1050 ft. deep. They made some profit.
The mine plant includes an Imperial Type-10 air compressor with
50-h.p. motor, drill sharpener, hoist and 52-h.p. motor. The milling
plant contains a rock-breaker, ten 1050-lb. stamps, with 50-h.p. motor ;
3^-ft. Hardinge mill, two old vanners and several small electric motors.
There are 13 old wooden buildings on the claims.
MOTHER LODE GOLD BELT 191
METALLURGY
From the beginning of quartz mining in California until only a
few years ago progress in ore treatment has been directed largely
along one line, the improvement of the gravity stamp mill and the
increase in its capacity. The stamp, after the arrastre, was the first
ore-crushing machine brought to the attention of the miners. There
are many reasons why it should have intrenched itself in favor, and
maintained its place. The first of these was its simplicity and general
dependability. Stamp stems, shoes, dies, cams and tappets are simple
to make and install. The earliest mills had square wooden stems, and
square shoes and dies, wooden mortar blocks and mortars too large
in capacity. The first improvement was to provide rotation (said to
have been made by George Stanford), in order to give even wear on
shoes and dies. The circular stem, the cam, and the tappet were thus
evolved. The next problem was to increase capacity. This could be
done in many ways — heavier stamps and larger stamping surface, more
drops per minute, higher drop, lower discharge and coarser screening,
and with less space in the mortar. Of all these factors, the tendency
has been to increase stamp weight most noticeably, and increase the
running speed, i. e., number of drops, somewhat, and reduce space
inside the mortar. Other variants have remained quite constant.
Weight of the stamp assembly has thus been increased along the Mother
Lode from 250 lb. to ,1250 lb. The only other radical change over a
long period of years was the adaptation of stamps as intermediate
crushers, followed by Hardinge mills.
Some of the other advantages of the stamp battery as a unit in ore
treatment are: (1) jNIoderate power needed, and no excessive power
required for starting. (2) Quick and simple cleaning up of one
battery at a time, without necessity of stopping the entire mill. (3)
Range in size of ore fed and in reduction. (4) Quick and simple
replacement of worn parts, with wear mostly on cheap parts. (5) Low
operating costs.
An interesting example of the advances made in the evolution of
the stamp-mill was the addition of 20 stamps to the Lightner mill of
40 stamps at Angels Camp. This addition, although it was built
in 1907, shows what good Mother Lode practice was at a time when
large tonnages of low-grade ores were being handled. Its specifica-
tions were :
Stamp weight complete, 1000 lb. Drop 7 inches, 106 times a
minute; height of discharge above die (new) 7| inches. Shoes were of
chrome steel and Pennington hammered steel, weighing 181 lb. new and
25 to 30 lb. when worn out; they lasted 10 months. Dies were of semi-
steel, 5^ inches high, weight 82 lb. new and 30 lb. when worn out;
they lasted 8 months. Thirty-mesh punched screen was used, and each
battery had 308 sq. in. of clear screen. The mortars were of 'close
pattern,' with no surplus room either between the stamps themselves
or between stamp and mortar lining. The stamp stems were held
192 METALLURGY
rigidly in line by Pacific Battery Stem Guides. The mortar blocks
were of sugar pine on concrete foundations. Each battery had 88 sq.
ft. of outside copper plates (2 plates each 2 ft. by 22 ft.) with 2^ oz.
of silver plating per sq. ft. The grade was 2 in. per ft.
There were three 4-ft. Frue vanners for each 5-stamp battery.
The water required for each battery was 8 gallons per minute, and
for each concentrator, 1 gallon per minute additional.
The capacity of these stamps (over 5 tons each in 24 hours) was
10% to 15% more than in the old mill, with no more power required
and no greater tailing loss. The recovery of gold inside the mortar
was 25% as compared with 20% in the old mill. The shoes and dies
also had longer life. The recovery was 92% or better with a tailing
loss of 20 cents to 25 cents a ton on ore ranging in recovered value from
$3 to $4 a ton in 1907 and 1908.
The 20 stamps, 12 Frue vanners, 36 ft. of 4-inch mill line-shaft
and 34 ft. of 2-inch counter-shaft for concentrators required 40 h.p.
The labor cost for milling had averaged 22| cents a ton with the old 40
stamps; with the 20 new stamps added, the cost of this item was
reduced to from 15 to 20 cents a ton.
This mill addition was designed by D. C. Demarest and all of the
iron work was done by the Angels Iron Works, Angels Camp. Here
was another reason why the stamp mill was so popular; there were
(and still are) several such foundries along the Mother Lode that
have done good work in the designing and making of large stamp
mills, and supplying parts which required periodical replacement,
obviating the necessity of going elsewhere, and the delays due to
shipping from a distance, particularly during the many years before
the advent of the automobile, when roads were impassible during the
entire rainy season and until late in the spring.
Companion to the stamp mill in most of the plants was the endless
belt vanner, generally the Frue, although modifications of it, and
others such as the Johnston and Tulloch were also used. The prin-
ciple on which these work is the separation of the heavy minerals
(sulphides and gold) from the lighter (quartz, slate or other gangue)
in a lower layer by mechanical agitation on a shaking and upward-
moving surface, generally a smooth belt of 2-ply rubber with upturned
sides. The dragging action of the upward-moving belt to which the
heavy sulphides cling, permits them to be carried over the upper end
of the vanner and down into a box filled with water, into which they
drop. Meanwhile the lighter, upper layer of gangue is being washed
downward and off the lower end of the belt into a tailings launder
by fine streams of water. The belt travel on these vanners ranges from
2 to 5 ft. a minute. The side shake, with a throw of about an inch,
is made at the rate of from 180 to 216 times a minute. The power
required for a vanner is therefore small, from one-fourth to less than
one horsepower. The capacity depends on speed and grade (slope
of belt) of the vanner and pulp size, varying from 4 to 7 or 8 tons each
24 hours. Excessive belt speed may lower saving.
Originally intended for handling fine sands and slimes, the vanners
in Mother Lode mills have usually been run directly on the pulp from
the amalgamating plates, without classification, and so have really
given excellent results, considering the wide range of screen sizes of
feed. A check of the pulp passing onto the plates and thence directly
MOTHER LODE GOLD BELT 193
to Frue vanners at the Argonaut mill in 1913 showed the following,
using a 16-mesh battery screen :
Screen size Per cent
On 40-mesh 13.33
On 60-mesh 16.67
On 80-mesh 11.67
On 100-raesh 9.33
On 150-mesh 6.67
On 200-mesh 5.84
On 300-mesh 1.50
Through 300-mesh 31.67
At that time, the tailing from the vanners was run over a buddle
30 ft. in diameter and with 16 decks. The 16 vanners were saving 3^
tons of concentrate daily and the buddle less than one-half ton daily.
Sixty per cent of the gold was saved by inside amalgamation, 10% on
the plates and 15% in the concentrate.
Classification had not given any notable or consistent increase in
saving where it had been tried; up to the time of the war the only
companies that tried it seriously were the Original Amador and the
Plymouth. The flow sheet at the former property in 1915 is shown,
post, as one of the steps in Mother Lode metallurgy. The ore at that
mine, however, is 'gray ore,' entirely different from the slate-quartz
ores of the mines working in the Mariposa slates.
The treatment of concentrate by chlorination began at an early
date, and the process survived at the Kennedy Mine until 1915. This
mine also had a large canvas plant for the treatment of tailing after
it passed the vanners and this was the last of its kind in commission
on the Mother Lode. The advent of the cyanide process about 1896
at once drew attention to the tailings from the quartz mines and many
efforts to so treat these tailings (especially those from the slate ores)
were unsuccessful. Concentrate for the most part was shipped to Selby
smelter on San Francisco bay.
For many years re-precipitation or adsorption of gold by the
carbon in the Mariposa slate was believed to be the reason for the
failure of the cyanide process to give satisfactory results on these
tailings and concentrates. The tendency of the slate to form slime in
the stamp mill also was a bad feature. In 1922 it had been noted at
the Belmont Shawmut Mine in Tuolumne County in the course of
experimentation in ore dressing, that the oil-floated concentrate made
at that time (as distinguished from the present-day flotation concen-
trate, produced with the use of many chemicals) responded better to
cyanide treatment than the table concentrate. Accordingly, 8 to
10 lb. of California crude oil was added per ton of concentrate when
regrinding preliminary to cyanidation.
Somewhat later, at the plant of Amador Metals Reduction Com-
pany, a custom cyanide plant treating the entire mill tailings from
the Argonaut mill (see flow sheet, post) the use of certain soluble
coal tars for temporarily inhibiting the precipitating action of the
carbon in the slimes was introduced. About 4 lb. of such coal tar per
ton of slimes is used. An emulsion is formed by agitating the slimes
and coal tar in three tumbling boxes. The effect is only temporary,
and the slimes must be sent within a few minutes to the Devereaux
13—4156
194
METALLURGY
Flow Sheet No. 12.
AMADO/7 METALS PSDUCT/Of/ CO'S CYAN/DE PLAA/r FOR SAND AND SL/ME .
Sanef anof 5//me. TarZ/n^ from Arqorrauf M/// in p/pe
Go/d Su/rrp
\2 Dorr T/r/cZraners T
■^ ' ■40'XS' I
SO/iso/,c(s
\ Zmc Dusf
~ Frecip/faf/'on
J 3 Tumb/zf}^ Soxes
\
X
Acicf Tresfmenf
Cenfr/'fuga/ Pump
Vaci/um Fecs/ysr
A-'x 6'
Q
Coa/ Tar added
L
Ag/Va/or
Cyan/de
added
T
0//yer ////fer
/a'x /z-
Darrotv ////<sr /Z'x/e'
So//ds rspu/p«d tv/fA
~Y barren So/cr//on
A^fifafor
Accompariyrnof Suf/ef/n /OS, by C A Log's n.
MOTHER LODE GOLD BELT 105
agitator for eyanidation, and after 20 minutes treatment there, to the
filter.
In 1930, Leaver and Woolf in Technical Paper 481 of the U. S.
Bureau of Mines, made public the results of some tests on slime tail-
ings from several of these mines. Instead of treatment with coal
tar previous to eyanidation, 3 to 5 lb. of paper-mill waste sulphite
liquor per ton of tailings was used. The tabulation of results shown
below is summarized from their report.
Percentage of gold extracted in eyanidation tests on slimes from
Kennedy Argonaut Central Eureka Plymouth
Untreated slime 67.8* G0.7 14.8 27.7
Treated slime 75.0 71.5 61.0 53.2
* Sample contained 15% fine sand.
These tests also indicated that the cyanide solution acted very
rapidly in dissolving the gold in the Argonaut slimes, only 5 minutes
agitation of untreated slimes giving higher extraction than 2 hours agi-
tation. It can not be definitely stated whether the remaining gold
(34.7%) was entirely lost by adsorption or re-precipitation by the
carbon, or was held in some form insoluble in cyanide.
The practice of u.sing stamp mills and vanners on the Mother Lode
to the exclusion of nearly all other equipment has often been criticized.
But after all, the working of a mine is a business adventure, the sole
aim of which is to make the largest net profit possible with a given
investment. In the case of ores of as low average gold content as
those which have produced most of the tonnage from the Mother Lode,
an increased saving of 5% or 10% of gold content by another method
than stamp-milling might not be enough to pay for the capital outlay
for new plant and increased cost of treatment. There have even
been cases where putting a finer screen on a stamp battery was not
justified because of the reduction in capacity, although such a change
might decrease tailing loss decidedly. With $3 ore, tailing containing
30 cents a ton would not be unsatisfactory. If ore grades increase, or
if costs rise as they did in 1915-1916, when low-grade mines had to
close and only the better ore could be worked, tailing loss becomes
more important. With the background of 65 years of stamp milling
so briefly alluded to, the writer will trace the development of Mother
Lode metallurgy from 1914 to 1934. This can best be done by the
discussion and illustration of flow-sheets. Of those mentioned, 13 are
illustrated.
Plymouth Mill
The Plymouth mill, in 1914, was the first decided break with
precedent on the Mother Lode. It was the first property where ore
was delivered to the mill from the shaft by a belt conveyor, and
another conveyor distributed the ore over the mill-bins which were
flat-bottomed and had a capacity of 1400 tons. Thirtj^ 1250-lb. stamps
dropping 7 inches 104 times a minute crushed the ore to 4-mesh (0.19
in.) and had a capacity of 14 tons a day each. This was another
decided innovation. Classification began with the stamp pulp ; cones
separated the fines and sent them over ten 6 ft. by 12 ft. plates for
amalgamation while coarse feed went to two 8 ft. by 22-inch Hardinge
196
METALLURGY
Flow Sheet No. 1.
FLOW SHEET AMADOR CONSOLIDATED M/LL
AMADOR COUNTY ■ /S/S.
D.
^^* fVey3A>rs
i
Acre/ ''p„^^ Drying
Accompany/nq Bu//ef>/7 /08, iy C A. io^in
MOTHER LODE GOLD BELT 197
mills and after crushing, to the plates. The plate tailing was ele-
vated and again classified. The overflow of a sloughing-off cone went
to 24 Isbell vanners, and its underflow^ was again split into coarse
and fine parts by a Richards hindered-settliug classifier. The coarse
sand was sent to two No. 6 Wilfley tables which handled 35 tons each
and the fine sand was handled on six Isbell vanners.
Some of the results obtained with this mill were listed by Caetani
after it had been in operation two months. If amalgam were kept
soft by plentiful addition of mercury, amalgamation was complete in
the Hardinge mills but on cleaning up the amalgam was found in the
bottom of mill in a "slough of amalgam, iron and sand." When
insufficient mercury was fed, the amalgam hardened, crumbled and came
out of the mill. There was a large mercury loss in the Hardinge mill.
The 2-stage crushing reduced the wide range of screen sizes of
product and was believed to give a lesser percentage of colloidal mate-
rial and to increase recover^-. The mill crushed 95% through 60-mesh
and it was estimated the Hardinge mills were doing work equivalent
to that of 50 stamps at a cost of 11.4 cents a ton.
The largest percentage of total gold loss was in the colloids.
Caetani believed this was probably due to floating of arsenopyrite.
(It is interesting to note here that in analyses of slimes from the
Mother Lode mills reported in U. S. Bureau of Mines Technical Paper
481 that from the Plymouth contained 18.04% AlgOg, 5.15% K2O and
0.20% arsenic, but less sulphur than the Kennedy, Argonaut or Central
Eureka slime).
The percentage of recovery indicated by 45 assays of mill-heads
and 49 of total tailings was between 88% and 89%.
Original Amador Mill (see Flow Sheet No. 1)
This mill was remodelled, with the addition of much machinery
in 1915. Previously it had contained twenty 1000-lb. stamps dropping
105 times a minute and crushing 90 tons daily through 20-mesh wire
screen, with inside and outside amalgamation, and concentration of
sulphides on 7 Deister concentrators and 1 Frue vanner. After the
change, the mill handled 300 tons daily and a recovery of 90% was
claimed. The ore was the 'gray ore' of the lode consisting of hydro-
thermally altered greenstone containing 3% to 5% of sulphide. Most
of the gold was in the sulphide and the ore averaged $3.50 to $4 a ton
in gold.
Inspection of the flow sheet shows the emphasis laid upon classifi-
cation or sizing. This began with screening even ahead of the stamps.
Slime was separated following stamping, and concentrated on Deister
slime tables. Another novelty Avas the Trent Thickener, Agitator and
Replacer combined. Concentrate was ground to -200 mesh in a 4| ft.
by 72-inch Hardinge mill in closed circuit with a drag classifier and
grinding in cyanide solution. A Hardinge amalgamator and small
plate below this mill saved 5% of gold freed in grinding before cyanida-
tion.^ 0 'Brien described the process of cyanidation as follows :
"The overflow from the classifier is pumped to one 18-ft. diameter by
12-ft deep treatment tank equipped with the Trent cyaniding apparatus.
This tank, with a dillution of 70%, has a capacity of 30 tons of concentrates.
When starting to grind a charge, the treatment tank is filled with barren
1 O'Brien, T. S. Eng. & Mg. Jour. Vol. 100. No. 7, p. 256.
198
METALLURGY
solution and the circulating pump started while the valves are set to operate
as a thickener and replacer. Then the pulp from the classifier, having
about 80% dilution and having had about 50% of the values dissolved during
grinding, is pumped into a 12 x 12-in. box hung in the center and submerged
3 feet. While the charge is being ground and thickened in the bottom
of the treatment tank, the clear overflow, with a large percentage of the
dissolved values, goes to the sump tank, which has a filter bottom. After
the charge is ground and previous" to agitation, about 50% of the solution
Flow Sheet No. 2.
FLOiV SHEET DUTCH-APP MILL TUOLUMNE COUNTY ( /3/S)
0/7 F/ofafion" usingr p/ne o//^ i^afei — gss far, sfoye oi/ ancf c^eosofe.
S/uice P/afes
F/ofaf/on Tai/inq
,/7ouq/ier J Concenfrafe
C/eaner Concenfrafe
fo ^ Wi/T/ey
Tab/es
Tabfe Procfucf fo Sme/f^r
Diaphragm Pump
Sme/fsr
Accompanying Bii//ef/n /OS, by C.A togs-
in the treatment tank is replaced with barren solution and the valves on
the treatment tank changed to operate as an agitator. This process is con-
tinued for 6 or 8 hr. after which all the recoverable values are in solution.
The valves are again changed on the treatment tank so as to operate it
as a thickener and replacer and about 10% in excess of the solution in the
treatment tank is replaced with barren solution. Then 20 tons of wash water
carrying about 2 lb. alkalinity per ton, is added and the charge allowed to
settle into the wash water. The solution above the pulp is then decanted
off into the sump tank, and the pulp sluiced to waste."
MOTHER LODE GOLD BELT 199
This plant was closed in 1917 because of trouble with nearby land
owners over tailing disposal.
Dutch-App Mill, 1919 (see Flow Sheet No. 2)
Flotation was introduced on the Mother Lode at about the same
time on this property and on the Belmont-Shawmut. Although the
ores are quite similar, that of the Dutch and App Mines was coming
from shallower depths (between the 1500- and 2300-ft. levels) and
contained more free gold. It contained dolomite (or ankerite) mari-
posite, stringers and bunches of quartz, altered amphibolite schist and
Calaveras (Carboniferous) slate. Ore of a maximum size of three
inches was fed to the Hardinge mills which ground to -80 mesh.
There was ample plate surface for amalgamating both coarse and fine
gold. For flotation, pine oil, water-gas tar, stove oil and beechwood
creosote were used. The concentrate recovered (nearly all pyrite)
made up 8% to 10% of the ore and was worth $40 a ton. A recovery
of 90% to 92% was claimed on ore said to average $5 a ton, and
probably selected.
This plant never reached its rated capacity of 500 tons a day
during the short time it was in operation, so that no representative
cost figures were achieved. While crushing 150 tons a day the milling
cost was higher than such ore could stand, though the method was
technically satisfactory so far as could be learned.
Treasure Mill, Amador County, 1920 (see Flow Sheet No. 3)
This mill represents a transition stage, in which stamps were
dispensed with but the operators were not inclined to go so far as to use
the flotation process. Accordingly they resorted to repeated classifica-
tion, beginning with the screening out of fines from mine-run ore even
before primary crushing, and to 2-stage crushing, as well as to ample
provision of amalgamating plates and the use of proper tables for the
concentration of three different sizes of product. The work of the Frue
vanners, which had in most previous mills been loaded with an unclassi-
fied feed direct from the stamps, was here confined to the treatment
of slimes and very fine sand overflowing from the last classifiers. A
separate bin for fine ore permitted running the small Hardinge mills
when the large one was idle for repairs.
When operating two shifts this mill handled 90 tons, although
rated at 150 tons per 24 hours. The principal motors were one of
35 h.p. on the large Hardinge mill and 75 h.p. on main drive. The ore
was the 'gray ore' of the lode, carrying 3% of pj'rite concentrate worth
usually over $100 in gold (5 oz.) and $1 in silver per ton.
Belmont-Shawmut Mill, 1922 (see Flow Sheet No. 4)
During the long history of this mine various methods of ore
treatment were used. Originally, in working the ores of the shallow
zone where considerable free gold occurred due to secondary enrich-
ment, stamp mills were operated and $18 a ton was recovered by
amalgamation. Later the sulphide zone yielded much lower-grade
ore but still considerable free gold occurred. A 100-stamp mil] with
1000-lb. stamps and 40 Frue vanners was used and the concentrate
200
METALLURGY
was treated by chlorination. This mill was used until Belmont Mining
Company took the property.
Under this company, four types of ore were worked, which were
designated for convenience at the mines as banded quartz, impregnated
schist and dark and light sulphide ores. Pyrite is the chief sulphide.
Flow Sheet No. 3.
fLOW SHEET TREASURE M/LL AMADOR COUNTS ■ /320.
Ama/^amafion ancf Concenfraf/orr yv/Yfy repeafec/ c/ass/f/caf/or?
} ( <^J''3fOfy Crusher
/?eyo/yrnff Screen
^^ Oi'erstze ^ \ '(2) 7">f/0" Dodge C-usfrer
^Z'/e'- /^a'
' ' r-w 5ma/l Msrcf/nqe-
Pump
Bunker M,/r n
Screen (J ^ Fines - BO mesh
Cone oferf/okv fo8 frue y^nners
for Ama/gremahorj
S Sfafionary p/afes
To Sme/fer
Accompanying Suffef/'i7 /OS, by C. />. i.o^an
During the later operations concentrate saved was 7% to 10% of the
tonnage milled. At first the company installed Jones-Belmont flota-
tion cells to supplement the work of the stamp-mill, and made two
grades of concentrate, one on the vanners and the other by flotation.
The low grade of the concentrates and the high cost of shipment
MOTHER LODE GOLD BELT
201
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Oi ^
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^1
ti^
$ it
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202
METALLURGY
and smelter treatment left such a small margin of profit that experi-
ments in cyanidation were begun. In the course of these experiments,
it was found that the oil-floated concentrate responded better to cyanide
treatment than did the straight table concentrate.^ Analyzing the opera-
Flow Sheet No. 5.
FLOyi/ SHSET, CENr/?AL £U/?£/CA M/N/N3 COMPANY.
AMADOR COUNTY , /55^.
Sfamp/n^ J ame/^amafrorr an</ coneenfra/ion .
reed4''^
To^a/ Sfamp
capac/fy /■4C-/SO/C/TS
/rr cV Tirs. through
24- mesh screen
Ml// Bins, s/op/n£f 6o//om
t t t
■40 s/amps, //SO/b. each
Main /n/// e/r/y& /OO/tp. 440 t^o//
/S/ amp. 60 cyc/e e/ec/r/c moh?r
Separafe puZ/sy /or each /o s/amps
Si/^'ar p/a/ec/ ama/^amaZ/rr^
I /6 Frc/e yanners, /B'/orr^,
J I I runrr/pg^ a/
/SO s/ro^ss per mfnL/f»-
Concen/rafa fo custom cyanfcfe. p/arjf
yarrner Ta///hcr i'o s/oracfe- cfam
Accompany/nef Si///e//n /08, iy C^ iocfarr.
tions, it was concluded that the oil used in flotation was responsible for
this. There was enough carbon in the ore to cause the same premature
precipitation of gold experienced in trying to cj^anide slimes from
some of the Amador County mines. The flotation oil was apparently
giving the same action in temporarily coating and de-activating the
carbon, as was later achieved by Amador Metals Reduction Company,
who use water-soluble coal tars. However, if the investigators at the
Shawmut Mine realized what they had discovered, no announcement
was made.
While it was found that flotation was technically successful on this
ore, it was more expensive than results justified. The flotation cells
were therefore removed and the flow sheet outlined was put into use.
There was so little free gold in the deeper ores (between 2600 and
2900 ft. on the dip) that there was no provision for amalgamation.
The advantage from the use of oil was preserved by adding 8 lb. to
10 lb. of California crude oil per ton of concentrate to the tube mill
circuit while grinding for cyanidation. This flow sheet was used until
work stopped in January, 1924. A recovery of 90% to 92% was
claimed and a total milling cost of $1.22 a ton was reported late in
1922.
Central Eureka Mill, Amador County, 1934 (see Flow Sheet No. 5)
This is the only mill of any size on the Mother Lode which retains
simple stamp milling, amalgamation and concentration of unclassified
pulp on vanners. It is an old mill, built by Knight & Company of
1 Logan, C. A. R. XVIII of State Mineralogist, pp. 748-751, 1922.
MOTHER LODE GOLD BELT
203
Sutter Creek and tliougli the 40 stamps have not been in continuous
operation, they have crushed over a million tons of ore since 1911.
The main drive motor is of 100 h.p. (440 volts, 121 amperes and
60 cycles), and there is a separate pulley for each 10 stamps. Stamps
fully shod weigh 1280 lb. and drop 96 times a minute. The load per
vanner averages about 9 tons a day. Most of the ore handled has been
the slate and quartz ore found as lenses and stringers in the Mariposa
slate. An analysis of the slimes from this mill made by Peirc^ R.
Perry of the U. S. Bureau of Mines showed 55.02% SiOg, 19.43%
AI2O3, 3.72% Fe, 2.74% CaO, 2.31% MgO, 4.98% K,0 and 2.24%
carbon, indicating a higher content of alumina and carbon than in the
similar carbonaceous ores of the principal near-by mines. These last
two constituents made a particularly difficult slime to treat by cyanida-
tion, so that in preliminary tests by the U. S. Bureau of Mines (see,
ante) an extraction of only 14.8% of the gold was obtained by cyanida-
tion of untreated slimes. After pretreatment with 5 lb. of paper-mill
waste sulphite liquor per ton of tailing, an extraction of 61% was made.
During the entire period of operation of the Central Eureka claim
this tailing was run to waste or stored in a tailing dam without treat-
ment. Within the last year a cyanide plant has been built to treat
it and it is reported that a recovery of over 70% is being made on the
Tailing disposal from mill of Central Eureka Mine, Sutter Creek, Amador County.
Photo by Walter W. Bradley
slime and still better on the sand, though this has not been substan-
tiated by personal inquiry.
For the period 1920-1930 the company claimed to be making a
recovery of from 89% to 94.31% of mill-heads. The latter figure was
204
METALLURGY
claimed when mill-heads averaged $13,148 a ton for a year, and was
probably due to the larger proportion of coarse free gold as compared
to gold in sulphides. This ratio has varied from 6 :1 to 3 :1. Tailing
assays were reported from 64 cents to $1.12 a ton. The management
believed much of the tailing loss was due to very minute particles of
sulphide in the gouge, and to flakes of gold telluride said to occur
occasionally in high-grade spots.
■ In the Old Eureka Mine, from which mill tonnage has been com-
ing during the past few years, the ore is now 'gray ore,' about 90%
Flow Sheet No. 13.
rLOyv SHEET AMADOf! STAR /HILL WEST AMERICAN CONS. GOLD MINES
.Amac^or Counfy Jun& 133^,
No. S Afc Cully crusher
\ I- Sfaqe Crushmq fo li "
Z Harc/inqe Mills
Tsilinq fo iv3sf&
Dorr DocbiG Class'/ f/er
Oyerl'lotv, €0% f/trou^.h 40- mesh
c* cleaner cells
''■'ack lo S-rie/fer
'Accompanying Su lie fin lOd, iy C A .
quartz, between greenstone walls on some levels. The percentage of
concentrate for the year ended April 1, 1934, was 1.45% and it yielded
$86 a ton. A recovery of 93^% of gold was claimed, with tailing
assaying 60 cents. The ore came from the 2100-ft. and 2300-ft. levels.
This mill is probably working at a lower cost per ton than any
other along the lode except the one at Carson Hill Mines. The total
milling cost (including treatment of concentrate but not overhead,
taxes and depreciation) was less than 90 cents a ton last year.
Kennedy Mill
In Mining and Metallurgy, April, 1932, Max Kraut had the
following to say regarding the experiments that led to the adoption
of flotation at the Kennedy Mine:
"In June, 1931, experiments were made on the ores from the Kennedy mine
at Jackson, Calif. Preliminary results indicated a substantial saving in recovery
and operating expense by replacing the extensive vanner plant by flotation. At
the Kennedy mill the ore was ground through 24-mesh in a battery of 00 stamps
MOTHER LODE GOLD BELT 205
handling about 270 tons of ore per day. The pulp was passed over plates, with
the plate tailing treated on a series of 24 vanners. Vanner tailing losses varied
(considerably, depending on the character of the ore, from $1 to as high as $3
per ton.
"Laboratory experiments were promising, so it was decided to install a 2-cell
flotation machine to test the ore in continuous operation, using the plate tailing
from one 5-stamp battery. This test work covered five months. Two distinct
characters of ore became apparent. From one section of the mine the gold was well
liberated at 24-mesh, at which a flotation tailing as low as 30 to 40c per ton was
obtainable. From other sections the tailing when grinding to 24-mesh was not less
than $1 per ton. Screen analysis of tailing, however, showed that grinding all
through 60-mesh would give a 20c tailing and grinding to all through 80-mesh
would permit a flotation tailing of less than 5c per ton on both types of ore. So a
flotation plant to take care of the entire tonnage of mill plate tailings was built
and went into operation a few months ago. E(iuipment included a 5 by .5-ft. Allis-
Chalmers ball mill in closed circuit with an 8 by 24-ft. Dorr classifier. A Dorr
thickener was installed to eliminate excess water from the plate tailing. A 10-cell
flotation machine, followed by a 2-cell cleaner, comprises the flotation equipment,
with\ a Dorr filter for dewatering concentrate.
"Results have fully justified the new Kennedy installation. Lately, tailing
assayed about 20c per ton and often is as low as 5c. Further reduction in tailing
losses is expected as present higher tailing is due to inefficient gi-inding and classi-
fication which throws oversize into the flotation feed. After these defects are
remedied tailing may be reduced even below 5c.
"Cyaniding at the Kennedy is difficult because the ore contains a large quan-
tity of carbonaceous or gi-aphitic material. This does not interfere with flotation
recovery, but does tend to lower the grade of the concentrate. In the cleaning
operation a good part of the graphitic material is eliminated, which brings the
grade of concentrate up to about $150 per ton. The grade of the vanner concen-
trate averaged considerably less than that.
"Addition to the cleaner cells of 0.1 lb. of soluble starch per original ton
of ore raised the gi-ade of concentrate to over $250 per ton, but these experiments
lasted only a few days on account of lack of equipment to handle the starch solu-
tion conveniently. The necessary equipment for preparing and feeding the starch
will probably be installed shortly whereupon a uniformly higher grade of concen-
trate should result.
"Reagent consumption at the Kennedy mill is about as follows : American
Cyanamid Co., No. 208, 0.03 lb. per ton ; ethyl xanthate, 0.001 ; copper sulfate,
0.01 ; and pine oil, 0.15.
"Although the minerals to be floated are much the same as in the Grass
Valley district, the same reagents can not be used. Xanthate is the only collector
required at the Murchie or North Star mine, but at the Kennedy mine this reagent
does not permit a good, recovery and it was necessary to use Aerofloat No. 208 to
obtain satisfactory i-esults. A small amount of xanthate is being used as a pre-
caution although all tests indicate that it has only a slight effect in reducing tail-
ing loss."
Montezmna-Apex Mill, El Dorado County, June, 1934
(See Flow Sheet No. 6)
This mill was erected by a company that had no previous experi-
ence in treating California Mother Lode ore, but had operated success-
fully elsewhere. It may be said therefore that California practice or
tradition did not influence them. The mill is a complete departure
from former local practice. The previous operator had made a
reported recovery of about 85% with stamps.
The ore (quartz and Mariposa slate) is very similar to that of
the active Amador mines, except that it comes from shallower depths.
At times coarse gold occurs, and ample provision for saving this will
be noted on the flow-sheet. There is considerable gouge on the footwall
side of the vein and this carries enough gold along the ore-shoots to be
206
METALLURGY
MOTHER LODE GOLD BELT 207
milled. The pulp-sifting cloth is an innovation in California. Booth
Agitair flotation cells are also used here for the first time on the
Mother Lode. They use 2 to 3 lb. air and operate on a pulp of which
99% is -65 mesh and which is about 25% solids. Reagents are amyl
zanthate, cresylic acid, Aerofloat 15, copper sulphate and sodium
sulphide. About 240 tons of ore was being handled daily in June and
a satisfactory recovery was claimed. About 70% of gold is saved by
amalgamation and 30% in concentrate, which forms 3% of ore. There
is enough arsenic in the ore to necessitate shipping concentrate to a
Utah smelter. The total milling cost is among the lowest on the Mother
Lode.
Carson Hill Mine, Calaveras County, 1934 (see Flow Sheet No. 7)
This mill is at present handling a large tonnage of low-grade, the
company claiming a capacity of 20,000 tons a month. The plant was
designed and built in 1919-1920 for the original Carson Hill Gold
Mines, Incorporated, and was rehabilitated with some changes in 1933.
This mill crushed most of the ore produced by the former company,
reaching a capacity of over 15,000 tons a month. The period of opera-
tion has not been long enough under the present company to establish
average cost figures, but it seems obvious that these must be lower
than at other Mother Lode plants. This is due both to the scale of
operations and to the fact that a large part of ore is soft, oxidized
and earthy material from open pits.
Beebe Mill, El Dorado County, June, 1934 (see Flow Sheet No. 8)
This is an experimental plant and it is quite possible that the flow-
sheet shown will have been altered before this report is published.
The Hadsell mill is a recent invention which is here having its
first large-scale tryout. As is the rule in nearly all such cases, many
unpredictable changes have been required and other alterations are
indicated, before this mill can be expected to do justice to its inventor's
basic idea. It is essentially a partially enclosed wheel 26 ft. in diam-
eter, revolving at the rate of 2.7 r.p.m. Around its inner periphery is
arranged a series of shelves or open ore scoops (see photograph), which
at the lower part of the wheel's revolution pass into a sump, where
the scoops pick up a load of pulp. Projecting into the space enclosed
by the wheel and at the surface of this sump, are the seven heavy
steel ore-breaking plates. The mill depends entirely on gravity for
ore crushing. As the ore scoops rise from the sump with 600 lb. of
ore each the ore begins to slide off as the bottom of each scoop passes
the angle of repose for the wet pulp. The ore is crushed by falling a
distance of from 11 to 16 ft. upon the breaker plates and the picking
up and dropping of ore continues until it is fine enough to be carried
off through the screen on the side of the sump, the motion of the buckets
through the sump giving enough agitation to prevent packing.
Originally rock as much as one foot in diameter was fed to the mill,
but during the last year 6-inch to 8-inch feed has been used. For a
time a load of two tons of balls was tried, but these have since been
discontinued. In October, 1933, it was said one mill using 85 h.p. was
crushing 11.2 tons an hour of which 85% was finer than 200 mesh. The
two mills are each run by a motor rated at 100 h.p. which is mounted
208
METALLURGY
Flow Sheet No. 7.
F/oiv Sheef- shoyv/n^ pr/nc/p3/ sfeps in crushing, concenfra^/on anof
3m3/q3m3f/on prevfous fo c/an/cfaf/on^ <?/ C3rson M/// M/'nes /n
Ca/syeras Coun^. One s/c/e of m/// s^oi^n.
Ml// capac/Yy @ ^O, Ooo Tons 3 monf/r.
Juns, /93-4:
,kocc^,ooj 31^ s/amps crus/r/nq f/,rougA j-
■T " / /aSO /6.e3c/r, /OO ^rops a
' C/3SSi/'rer '
? barrA-s of
sma/ffama/zn^
p/a/es
Cone unc/erf/otv (coarse') from
esc/7 /O stamps
fo //arc//n^e M//.
Cone overf/o>y
fo p/a/es
Cona \ I Cone. \ Coneoyerf/Oiv /o
Sma// //arcY/n^'e.
Cone unc(erf7oyv
fo shafcna
P-'afes for . i
ema/^famar/on
Sma// //are//nge. A////
€>
C/ass/f/'er oyerf/pyv
[:
-= Ama/giarrt
-- frsps
Dra^
C/ass/f/er
/2f/ 8a// M///
sZ/nres freafea/ by a^/yaf/on
Accompany/n^ Bu//efin /Od /^y CA Lo^an.
MOTHER LODE GOLD BELT
209
Flow Sheet No. 8.
BEBBE M/LL OF PAC/F/C M//V/NG COMPANY, GEOPGETOyVA/ (/S3^)
CF/ofahbn 8r Cy3m'cf3f/on) Cour/es/ of /fo^er Derr/r/s^ Ass/. Sup f.
Ore, from A /pine, SeebS' S^ Eur&A-a M/nes
Coarse, Ore 3/rr
^ 1 B^^x 36' B/3/re CrusAer
^ sef fo 8 /nc/'res
e/ec^r/c moror
3ne( c/rs/n etr/y<e.
on eec/r m///.
Capac/fy of each
77/ ff BOO /ons af3/7y
F/rre Ore B/rr
qi*--/oo /rp. mofor
2- 26' X ^^' //3c/se// M///S
/n c/osea c/'rcu/Y yy/y/r a
~ Cab/e </r3^ c/ass/fer
C/ass/fer
Ovarf/oyv fo 2 banks of f/o/af/'on
ce//s. /2 /Crauf ceUs fo
each barrh.
I I Thickener for
V J Dei^afer/n^ concenfrafC'
^^ Under f /on, SO% so/f'e/s
C/assffi'er oyerfJory '
- 400 mesh
Tyvo SO'Kd
Derereaux
A^f/afors
14 — 415G
FT
S'x8' hfarcy /H///
in c/osec/ c/rcu// >v/Yh c/3SS/f/er
Three /e'x 6' Thic/ceners ^^^^ ^^^^
Prec'pf/gf/on
Fresnanf , I I I I
So/ur/on l I I I
Accompany rncf Su//e//n /OS, by C A. loifgrf
210
METALLURGY
Flow Sheet No. 9.
FLOyy SHEET, KELSEY M/N/rVG COMPANY
EL DO/? A DO COUNTY
June, /934.
Coarse Ors B/'rr
fhrou^n screen^
F/'ne Ore S/rr
9" X /jf-" crusAcr
Coarse Ore S/h
looooo oooooi ^^ sfamps ^ .
crush/n^ fo t ^^C^
£'x5'
m'/f/'amson Ba/f M/71
in c/osecf c/rcaf/
mf/i 3 c/ass/f/er {Traps /or fr(^
_^ Ta/'/mq' fo yyasfe
o. 2 /6. per forr of a m/x^i/re'
J 8a f// Zanf/rafe snc^ -^
Ferr/aso/ Zarr/hafe ,' p/ne o}/^
j^ /6. per fo/7; CuSO^ , A/a^ S
ana sfarc/r.
F/ne pu/p, €0-/7resA
to f/ofaf/orr
fO h.p mofor
/Crauf Foug'her ce/fs
(Sb 3BO np.nr.
C/eaner ce//
Fi/fer
Truc/c fo SnTe/far
Accompany/'n^ SLf//e/-/n /Off, by C. A. Lo^an.
MOTHER LODE GOLD BELT
211
above the mill and runs it by a chain drive. The rated capacity of
mills in the flow sheet as illustrated for June was 200 tons each daily.
Another feature of this plant is the cyanidation of flotation con-
centrate, after grinding to -400 mesh. Combinations of cyanidation
and flotation are being used in other parts of the world, though gen-
erally to dispose of base-metal sulphides or other cyanicides by flota-
tion previous to cj-anidation for gold, rather than bulk flotation of
original ore, followed by cyanidation of concentrate as in this case.
The combination is indicated (if it can be made technically successful)
in this case due to distance from railroad, smelter charges, and grades
of ore handled. A maximum recovery of about 85% was claimed in
June, 1934, but experimentation is still going on.
The ores worked in this mill vary greatly in character. That from
the Beebe Mine is silicified schist yielding 6^% of concentrate. The
Alpine Mine ore is white, sugary quartz carrying free gold and only
one-half of 1% of sulphide, and carries over twice as much gold as that
from the Beebe. Some oxidized surface ore is worked also from other
properties being prospected.
Kelsey Mill, El Dorado County, June, 1934 (see Flow Sheet No. 9)
This mill had just been re-designed and rebuilt at time of visit
and had not been given a real working test, so little can be said about
its efficiency.
The screening of fine ore ahead of the stamps and the separate
fine ore-bin will permit running the ball-mill during stamp shut-downs.
The Williamson ball-mill though much used in Arizona, here makes it
Flow Sheet No. 10.
Sfemp/ng^ , ama/gemahon, f/ofaf/on anc^ £rra\^/i'_/ concenfraf/on
A sma// , simp/e p/anf comb/ningf o/cf and neyv processes .
Sena for M/n&, Tuo/umne Coun/y, June.^ /334:
Capacity, -40 fo £0 fans
a cfay.
o oo o o
o oo o o
/O stamps crusA/n£' fo — ■40-mas/r
screen C 30-/nes/7 screen can ia
t/secfj.
Ama/^ama^/on P/a/es
■4- JO-au/ F/ofaff'on Ce//s
Vanneru.s- — /tccompany/n^ 3t//fefm f08, by C A. Lo^an.
first appearance on the ]\Iother Lode. Another feature is the new high-
speed Kraut flotation machine, running at 920 r.p.m., a pair of
machines using 10 h.p.
212 METALLURGY
Senator Mill, Tuolumne County, 1934 (see Flow Sheet No. 10)
This, the only mill in operation on the Mother Lode in Tuolumne
County in June, 1934, is a small plant erected to treat ore from
shallow levels (100-300 ft.) in the Hitchcock claim, formerly a part of
the Dutch-App consolidation.
Flow Sheet No. 11.
fLOyV SHEET PAC/r/C M/N/NG COMPA/Vy'S P/NE T/?EE AND JOSEPH/NE M/LL.
MAR/POSA COUNTY J934-
A p//of /77/// /?3ncf//n^ bof/; s/afe - Cfuarfz anc/ gray ores.
Coarse refurnecf fo rrri// feeaf
5//me
pump
Sacked and shipped to sme/fer ^
Hand Zing lOl Tons a day, June /334.
Aceomp'ariymff Suf/ehn /OS, iy C.A. Lo^sn
It illustrates what can be done in a small way and at little expense
in combining the old stamp-milling processes with flotation, making
both vanner and flotation concentrate and amalgamating free gold.
Ten medium-weight stamps crush 40 to 50 tons daily through
40-mesh screen, but it was planned to install 30-mesh. Most of the
MOTHER LODE GOLD BELT 213
free gold is caught on the plates, though some escapes to be saved by
flotation. In the preliminary tests reported by Max Kraut, 44.5% of
the gold was saved by amalgamation and 47.4% in the rougher flota-
tion concentrate, with flotation cleaner concentrate giving 4.6% more.
In the mill, as shown, 4 Kraut flotation cells are used to take off the
first concentrate, and flotation tailing is run over two belt vanners.
Both kinds of concentrate are sun-dried and shipped to smelter. In
flotation, pine oil, pentasol zanthate Z-6 and Reagent 301 are used, the
last named being a powerful zanthate promoter. Sodium silicate
is also used in small quantity.
Definite figures of recovery could not be had, but evidently satis-
factory results were being obtained.
Pine Tree and Josephine Mill, Mariposa County, June, 1934
(see Flow Sheet No. ,11)
This pilot mill handles both the types of ore common to the Mother
Lode, producing a good grade of concentrate for shipment. Though
there is nothing complex about the flow-sheet, the differences in the
ores from the two mines require some care m flotation and the use of
more reagents than usual. The Pine Tree ore, carrying serpentine and
talc which tend to froth excessively, requires starch and sodium
hydroxide, and copper sulphate must be used later, improving recovery
and grade of concentrate. Other reagents used are cresylic acid,
zanthate Z6 and sodium silicate. The Josephine ore, carrying fine
gold in a gangue composed partly of graphite-bearing black slate is
easy to treat by flotation but difficult to cyanide effectively. The con-
centrate contains over 2% arsenic and 0.25% antimony, also unfavor-
able to cyanidation. Shipment to a smelter is therefore indicated, and
this makes a good grade of concentrate desirable. Accordingly, the
product made is considerably higher in gold content than other Mother
Lode concentrates. The arsenic content makes it advisable to ship it
to Tacoma smelter, where no penalty is assessed against the arsenic.
214 BIBLIOGRAPHY
BIBLIOGRAPHY
While not claimed to be complete, the following bibliography con-
tains references to most of the publications dealing with the Mother
Lode, its mines, and methods of mining and treating the ores. Gen-
erally speaking, all of these publications are out of print and to be
found for reference only in the larger public libraries, in technical
libraries such as that of the State Division of Mines and in the private
libraries of a few mining engineers. The only exceptions are a few
of the later chapters of the recent reports of the State Mineralogist
on the mines of the Mother Lode counties, which are superseded, so far
as the mines on that lode are concerned, by the present report.
Anonymous — Auriferous zones in the hanging wall of the Mother Lode of California :
Min. & Sci. Press, Vol. 7S, p. 507, 1899.
Anonymous — Physical features of the Mother Lode : Min. & Sci. Press, Vol. 68,
p. 17, 1894.
Arnot, S. L. — Mining methods in the Mother Lode district of California : Am. Inst.
Min. & Met. Eng. Trans., Vol. 72, pp. 288-304, 1925.
Also issued as paper No. 149(>-A., 17 pp., Sept., 1925.
Ashburner, William — Geological formations of Pacific slope : Mineral Resources of
the States and Territories west of the Rocky Mountains for 1866, pp. 41—42,
1867.
Bancroft, H. H.— California inter pocula, 1848-1856, pp. 237-240, 1888.
Becker, Geo. F. — U. S. Geol. Survey Geol. Atlas.
Placerville Folio (No. 3) 1893.
Jackson Folio (No. 11) 1894.
(also republished in part in Placerville, Sacramento and Jackson Folio
Reprints Nos. 3, 5 and 11, 1914).
Notes on the stratigraphy of California : U. S. Geol. Survey Bull. 19, pp.
18-20, 1885.
Bradley, W. W. — Mill of the Melones Mining Co. at Melones, Calaveras Co., Cal. ;
Min. & Sci. Press, Vol. 86, pp. 49, 52, Jan. 24, 1903.
Brewer, W. H. — On the age of the gold-bearing rocks of the Pacific coast : Am. Jour.
Sci., 2d ser.. Vol. 42, pp. 114-118, 1866.
Brown, J. A. — Amador County Mines ; Calaveras County Mines : State Mineralo-
gist's Rept. X, pp. 9&-123, 147-151, 1890.
Browne, D. Y. — The Mother Lode of California : Min. & Sci. Press, Vol. 77, p. 157,
1898.
(abst.) Eng. Index, Vol. 3, p. 462, 1901.
Browne, J. Ross — The Mother Lode of California : in Report on Mineral Resources
of the States and Territories west of the Rocky Mountains for 1868. pp. 14-19.
1868.
Mineral resources of the State and Territories west of the Rocky Moun-
tains for 1867, pp. 14-16, 21-30, 74, 1868.
Mineral resources of the States and Territories west of the Rocky Moun-
tains for 1866, pp. 205, 210, 1867.
Browne, Ross E. — The Mother Lode of California : Min. & Sci Press, Vol. 76, 1898.
Also in California Mines and Minerals (pub. by California Miners' Asso-
ciation) : pp. 57-72, San Francisco, Calif., 1899.
Caetani, Gelasio — The design of the Plymouth mill : Min. & Sci. Press, Vol. 109,
pp. 670-679, 1914.
California Miners' Association — California Mines and Minerals : pp. 305-318 (El
Dorado County) ; pp. 345-359 (Tuolumne County) ; 1899.
California State Mineralogist Rept. II, pp. 148, 175-178, 180, 182, 184-189, Appen-
dix pp. 20S-213, 1882.
Rept. IV, pp. 104 (calaverite), 219, 220, 222-224, 260 (mariposite), 1884.
Rept. VI, Pt. I, pp. 95 (calaverite), 110 (gold), 121 (mariposite), 129
(pyrite), 1886.
Rept. VI. Pt. II, pp. 15-23, 27-34, 43. 61. 18S6.
Rept. VIII. pp. 42-93. 96. 122-131. 141-143. 149. 167-171, 175-17S.
180-195. 34.5-347, 656-658, 660-664, 692-734, 774, 775, 1888.
Rept. IX, p. 37, 1889.
MOTHER LODE GOLD BELT 215
Rept. X, pp. 23-90, 98-123, 147-151, 170-179, 300-310, 734, 741, 857,
869, 871, 874, 880, 1890.
Kept. XI, pp. 139-146, 169-175, 200-204, 207, 493, 507-510, 1893.
Rept. XII. pp. 70-80. 89-99, 101-127. 167-176, 298-307, 1894.
Rept. XIII, pp. 65-81, 96-125, 131-165, 216-225, 472-496, 665-672, 1896.
Rept. XIV, pp. 14-52. 65-113, 135-166, 570, 575-599, 1914.
Rept. XV, pp. 278-300, 1916.
Rept. XVII, pp. 86-99, 105-142, 406^12, 419-428. 479-486, 1921.
Rept. XVIII, pp. 44, 78, 97-101, 124-125, 144, 208-210, 298-301, 365,
366, 739, 748-750, 1922.
Rept. XIX, pp. i;3-19, 59, 144, 1923.
Rept. XX, pp. 1-5, 19, 20, 74, 76, 177, 178, 183, 1924.
Rept. XXI, pp. 144-161, 1925.
Rept. XXII, pp. 409-430. 1926.
Rept. XXIII, pp. 149-197, 1927.
Rept. XXIV, pp. 8-41, 79-121. 124-142, 1928.
Rept. XXVIII, pp. 291, 297, 1932.
Cal. State Min. Bur. — A Review of Mining in California during 1919 : Prelim.
Rept. No. 6, pp. 14-18, 27, 1920.
A Review of Mining in California during 1921 : Prelim. Rept. No. 8,
pp. 21-30, 3^-41, 43, 1922.
Castello, W. O. — Mariposa County mines : State Mineralogist's Rept. XVII, pp.
86-99, 105-142, 1920.
Cloos, Ernst — Structural survey of the grandodiorite south of Mariposa, Califor-
nia : Am. Jour. Sci., 5th ser.. Vol. 23, pp. 289-304, 1932.
Structure of the Sierra Nevada Batholith : XVI Internat. Geol. Cong.,
Guide-book 16, pp. 40-45, 1933.
Collier, J. H., Jr. — Deep Mining at the Utica : Cal. Mines and Minerals (Cal.
Miners" Assoc.) pp. 97-113, 1899.
Also in Trans. Am. Inst. Min. Eng.. Sept.. 1899 (Calif, meeting).
Cronise, T. F., The Natural Wealth of California, 696 pp., 1868.
De Groot, Henry — El Dorado County Mines : State Mineralogist's Rept. X, pp.
169-179. 1890.
Diller, Joseph Silas — Tertiary Revolution in the Topographv of the Pacific Coast :
U. S. Geol. Survey, Fourteenth Ann. Rept., Pt. II, pp. 397-434.
Eakle, A. S.— Minerals of California : State Min. Bur., Bull. 91, 328 pp., 1923.
Eddy. L. H.^The Mother Lode region, Calif. : Eng. & Min. Jour., Vol. 95, pp.
405-410, map, 1913.
(abst.) Eng. Index, 1913, p. 380, 1914.
Emmens, S. H. — The Mayflower mine, California : Eng. & Min. Jour., Vol. 57, pp.
173-174, 1894.
The Mother Lode, Min. & Sci. Press, Vol. 67, p. 419, 1898.
Fairbanks, H. W. — Geology of the Mother Lode region : California State Min.
Bur. Tenth Ann. Rept., pp. 23-90, 1890.
(abst.) Amer. Geol.. Vol. 7, pp. 209-222, 1890.
"The great Mother Lode of California : Eng. & Min. Jour., Vol. 62, pp.
248-250, 1896.
(abst.) Inst. Min. Eng., Trans. Vol. 14, pp. 668-669, 1897-1898.
(abst.) Eng. Index, Vol. 3, p. 462, 1901.
Ore deposits with especial reference to the Mother Lode : Calif. State
Min. Bur. Rept. 13, pp. 065-672. 1896.
Fremont, J. C, and Billings, Frederick — The Mariposa estate. 63 pp.. London. 1861.
Goldstone, L. P. — Tuolumne County Mines : State Mineralogist's Rept. X, pp.
734, 741. 1890.
Hammond, J. H. — The Milling of Gold Ores in California : State Mineralogist's
Rept. VIII, pp. 692-735, 1888.
Mining of Gold Ores in California : State Mineralogist's Rept. X. pn.
852-882. 1890.
Hillebrand, W. F. — The analysis of silicate and carbonate rocks : U. S. Geol. Sur-
vey Bull. 422, p. 151, 1910.
Hittell, J. S. — The resources of California, p. 274, 1863.
Hulin, C. D.— A Mother Lode gold ore: Econ. Geol. Vol. 25, pp. 348-355, 1930
(ann.) Ann. Bibl. Econ. Geol., Vol. 3. p. 67. 1930.
Hyatt. Alpheu.s — Trias and Jura in the Western States: Geol. Soc. America Bull
Vol. 5, pp. 393^34, 1894.
Janin. Chas.— Operating Costs of California Mines : Min. & Sci. Press. Vol 105.
Oct. 26. 1912, pp. 520-523.
Jenkins. Olaf P. — Report accompanying geologic map of Northern Sierra Nevada :
State Mineralogist's Rept. XXVIII, pp. 291, 297, 1932.
Knopf, Adolph — Notes on the foothill c'opi)er belt of the Sierra Nevada : Cali-
fornia Univ. Dept. Geology Bull. Vol. 4, p. 419, 1906.
The Mother Ixxle system of California : U. S. Geol. Survev Prof. Paner
157, 88 pp., 1929.
(Review) Eng. & Min. Jour., Vol. 128, p. 24, 1929.
216 BIBLIOGRAPHY
Jour. Geol., Vol. 38, pp. 377-378, 1930.
(ann.) Ann. Bibl. Econ. Geol., Vol. 2, p. 64, 1929.
(abst.) Rv. Geol. et Sci. conn., Vol. 10, p. 325, 1929; G. Zentralbl 41,
pp. 364-367, 1930.
(Review) Geol. Mag., Vol. 67, p. 36, 1930,
The Mother Lode System : XVI Internat, Geol. Cong., Guidebook 16, pp.
45-60, 1933.
Knowlton, F. H. — The Jurassic age of the "Jurassic flora of Oregon" : Am. Jour.
Sci., 4th ser.. Vol. 30, pp. 49-50, 1910.
Laizure, C. McK. — Mariposa County Mines : State Mineralogist's Rept. XVIII,
pp. 144, 366, 1922.
Mariposa County Mines : State Mineralogist's Rept. XXIV, pp. 79-121,
124-142, 1928.
Lakes, Arthur — The Mother Lode of California: Mines & Min., Vol. 19, pp. 248-
250, 5 figs., 1899.
(abst.) Eng. Index, Vol. 3, p. 462, 1901.
Leach, F. A. — Fineness of California Gold: Cal. Mines and Minerals (Cal.
Miners' Assoc), pp. 175-187. 1899.
Leaver, Edmund S. (& Woolf, Jesse A.) — Re-treatment of Mother Lode (Calif.)
Carbonaceous slime tailings: U. S. Bur. of Mines Technical Paper 481, 1930.
Also same subject in U. S. Bureau of Mines Information Circular 2998,
Apr. 1930.
Lindgren, Waldemar — Mineral deposits, 3d ed., pp. 615-629, 1928.
Two Neocene rivers of California : Geol. Soc. America Bull., Vol. 4, pp.
257-298, 1893.
Lindgren, Waldemar — The Tertiary gravels of the Sierra Nevada of California :
U. S. Geol. Survey, Prof. Paper 73, 226 pp., 1911.
Characteristic features of California gold-quartz veins : Geol. Soc. America
Bull., Vol. 6, pp. 229, 234-235, 1895.
Lindgren, Waldemar (and Turner, H. W.) — U. S. Geol. Atlas, Placerville Folio
(No. 3), 1893.
Also in Geol. Folio Reprints 3, 5 and 11.
Lawson, Andrew Cowper — The Sierra Nevada : Cal. Univ. Chronicle 23, 130-149,
1921.
Logan, Clarence A. — Mother Lode Quartz Mines : Calif. State Min. Bur. Prelim-
inary Rept. No. 6. Jan. 1920, pp. 14-18.
Amador County Mines : State Mineralogist's Rept., XVII, pp. 406-412,
1921.
Calaveras County Mines: State Mineralogist's Rept.. XVII, pp. 419--423,
1921.
El Dorado County Mines: State Mineralogist's Rept. XVII, pp. 425-428,
1921.
Tuolumne County Mines: State Mineralogist's Rept. XVII, pp. 479-486,
1921.
Calif. State Min. Bur. Preliminary Rept. No. 8, pp. 23, 25-27, 29, Janu-
ary, 1922.
in State Mineralogist's Rept. XVIII, pp. 44, 78, 97-101, 124r-125, 208-
210, 298-301, 739, 74S-750, 1922.
in State Mineralogist's Rept. XIX, pp. 13-19, 59, 144, 1923.
in State Mineralogist's Rept. XX, pp. 1-5, 19, 20, 74, 76, 177, 178, 188,
1924.
Calaveras County Mines : State Mineralogist's Rept. XXI, pp. 144-161,
1925.
El Dorado County Mines : State Mineralogist's Rept. XXII, pp. 409-436,
1926.
Amador County Mines: State Mineralogist's Rept. XXIII, pp. 149-197,
1927.
Tuolumne County Mines : State Mineralogist's Rept. XXIV, pp. 8-41, 1928.
Loring, W. J. — Mill practice of the Utica Mills, Calaveras County, California :
Am. Inst. Min. Eng. Trans., Oct., 1898.
Reopening of the Plymouth Mine and the results : Min. and Sci. Press
Vol. 121, pp. 771-772, 1920.
Louderback, (George Davis — General Features of the Structure of the bedrock
complex of the Sierra Nevada: (abst.) G. Soc. Am., B. 24: 98, 1913.
Lowell, F. L. — Mariposa County Mines : State Mineralogist's Rept. XIV, pp. 570,
575—599 1914.
Lyman, S. c'.— Gold of California : Am. Jour. Sci., 2d ser., Vol. 9, pp. 126-129, 1849.
Maclaren, Malcom — The persistence of ore in depth : Cong. Geol. Internat., 12 sess.,
Compt. rend., pp. 300-301, 1914.
Gold, its geological occurrence and geographical distribution : pp. 69, 503-
507, 1908.
McLaughlin. D. H. — Review. The Mother I>ode System of California (Knopf) :
Econ. Geo!., Vol. 25, pp. 225-227, 1930.
MOTHER LODE GOLD BELT 217
Martin, A. H. — California Quartz Mining and its Future: Min. «& Eng. World, Vol.
35, pp. 571-572, 1911.
South Eureka Mine on Mother Ix)de, California : Min. & Eng. World, Vol.
35, pp. 155-156, 1911.
The Pioneer Gold Stamp Mills of Califoraia : Min. & Eng. World, Vol.
37, p. 332, 1912.
McCraney, Orlando A. — Mother Lode Mining Methods, an unpublished manuscript
(talk before Mining Assoc, of Calif., Sacramento, Oct. 19, 1928).
Min. and Sci. Press— Vol. 88, pp. 1, 5, 265, 313, Jan.-June, 1904; Vol. 89, p. 38,
July 16, 1904.
Moody, C. L.— The breccias of the Mariposa formation in the vicinity of Colfax,
Calif. : California Univ. Dept. Geology Bull., Vol. 10, pp. 383^20, 1917.
Moss, Frank A.— The Geology of Carson Hill : Eng. & Min. Jour., Vol. 124, No. 26,
pp. 1010-1012, Dec. 24, 1927.
O'Brien, T. S. — Amador Consolidated milling plant, Amador City, Calif. : Eng.
& Min. Jour., Vol. 100, pp. 255-257, 1915.
Olcott, E. E. — The Limitations of the Gold Stamp Mill : Trans. Am. Inst. Min.
Eng. (discussion), p. 551, 1893.
Parsons, A. B. — The mine and mill of the Belmont Shawmut Mining Co. : Min. &
Sci. Press, Vol. 121, pp. 61^-624, 659-664, 1920.
Penniman, H. W. H. — Mines of Calaveras County: Cal. Mines and Minerals (Cal.
Miners' Assoc), pp. 330-344, 1899.
Petre, R. W. — A few miles of the Mother Lode in California : Eng. & Min. Jour.,
Vol. 64, pp. 635-636, 1897.
(abst.) Eng. Index, Vol. 3, p. 462, 1901.
Phillips, J. A. — Notes on the chemical geology of the gold field of California :
Philos. Mag., 4th ser., Vol. 36, pp. 324, 333, 1868.
Preston, E. B. — California gold mill practices : Cal. State Min. Bur. Bull. 6, pp.
55-58, 64-70, 7^76, 1895.
Mariposa County Mines : State Mineralogist's Kept. X, pp. 300^310, 1890.
Amador County Mines: State Mineralogist's Rept. XI, pp. 139-146, 1892.
Calaveras County Mines : State Mineralogist's Rept. XI, pp. 167-178, 1892.
El Dorado County Mines : State Mineralogist's Rept. XI, pp. 200^207, 1892.
Tuolumne County Mines : State Mineralogist's Rept. XI, pp. 493-513, 1892.
Prichard, W. A. — Observations on Mother Lode gold deposits, California : Am.
Inst. Min. Eng. Trans., Vol. 34, pp. 454-466, 973-974, 1904.
(abst.) Eng. & Min. Jour. Vol. 76, pp. 125-127, 1903.
Ransome, F. L. — U. S. Geol. Survey Geol. Atlas, Mother Lode District folio
(No. 63), 1900.
Sonora Folio (No. 41), 1897.
Raymond, Rossiter W. — Statistics of mines and mining in the States and Terri-
tories west of the Rocky Mountains for 1875, p. 47, 1877.
Mineral resources of the States and Territories west of the Rocky Moun-
tains for 1869, pp. 30-31, 1870.
Statistics of mines and mining in the States and Territories west of the
Rocky Mountains for 1870, p. 30, 1872.
Mineral Resources of the States and Territories west of the Rocky Moun-
tains for 1868, pp. 11-12, 1869.
Statistics of mines and mining in the States and Territories west of the
Rocky Mountains for 1869, p. 456, 1870.
Statistics of mines and mining in the States and Territories of the Rocky
Mountains for 1873, p. 88, 1874.
Reid, J. A. — The ore deposits of Copperopolis, Calaveras County, California : Econ.
Geology, Vol. 2, pp. 380-417, 1907.
The country east of the Mother Lode (in Placer Co., Calif.) : Min. &
Sci. Press, Vol. 94, pp. 279-280, 1907.
R6mond, Auguste — Mining Statistics No. 1. Tabular Statement of the condition of
the Auriferous Quartz Mines and Mills in that part of Mariposa and Tuolumne
Counties lying between the Merced and Stanislaus Rivers: Cal. Geol. Survev.
16 pp., 1866.
Richthofen, F. von — Ueber das Alter der gold-fiihrenden Gange und der von ihnen
durchsetzter Gesteine: Deutsche geol. Gesell. Zeitschr., Band 21, pp. 723-740
1869.
Rickard, T. A. — The reopening of old mines along the Mother Lode, California:
Min. & Sci. Press, Vol. 112, pp. 93.5-9.39, 1916.
Certain dissimilar occurrences of gold-bearing quartz: Proc. Colo Sci
Soc, Vol. 4, p. 328, 1891-1898.
The formation of bonanzas in gold veins : Trans. Am. Inst. Min Eue
XXXI, pp. 214-215. 1901. '
Roesler. A. E. R. — Mining on the Mother Lode of Califoniia : :\Iin. & Soi Press
Vol. 122, pp. 807-809, 2 figs.. 1921.
(abst.) Eng. Index, 1921: p. 258, 1922.
218 BIBLIOGRAPHY
Rolker, C. M. — The lato operations of the ^Slariposa estate : Am. Inst. Min. Eng.
Trans., Vol. G, pp. 145-l(>i, 1879.
Schaller, W. T. — The probable identity of mariposite and allurgite : U. S. Geol.
Survey Bull. GIO, pp. 139-140, 1916.
Silliman, B., Jr. — Notes on three new localities of tellurium minerals in California
and on some mineralogical features of the Mother vein : Calif. Ac. Nat.Sci., Pr.
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Small, G. W. — Notes on the stamp mills and chlorination works of the Plymouth
Consolidated Gold Mining Co., Amador County, Calif. : Am. Inst. Min. Eng.
Trans., Vol. 15, pp. 305-308, 1887.
Smith, James Perrin — The geologic formations of California : California State
Min. Bur. Bull. 72, pp. 31-33, 1916.
Age of the auriferoiis slates of the Sierra Nevada : Geol. Soc. America Bull.,
Vol. 5, pp. 243-258, 1894.
Salient events in the geologic historj' of California : Science, new ser.,
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Geologic Map of California : California State Min. Bur., 1916.
Spiers, James-^Mining Methods and Costs at the Central Eureka Mine : U. S. Bur.
of Mines Information Circular 6512, Oct., 1931.
Stearas, H. T., Robinson, T. W., Taylor, G. H. — Geology and water resources of
the Mokelumne area, California : U. S. Geol. Survey Water Supply Paper
619, 402 pp., 1930.
Storms. W. H. — Some structural features of the California Gold Belt : Min. & Sci.
Press, Vol. 87, pp. 112, 129, 149, 165, 179, 183, 202, 216, Aug.-Oct., 1903.
Amador County's Mines: Cal. Mines and Minerals (Cal. Miners' Assoc),
pp. 319-329, 1899.
Mariposa County's Mineral Wealth: Cal. Mines and Minerals (Cal. Miners'
Assoc. ) , pp. 360-369, 1899.
Consolidation of Mother Lode mines, California : Min. & Sci. Press, Vol.
99, pp. 597-598, 1909.
Mining on the Mother Lode of California : Min. World, Vol. 35, pp. 841-
843, 1911.
(abst.) Eng. Index, 1911, p. 374, 1912.
The great east lode of California (Mother Lode) : Min. & Sci. Press, Vol.
70, p. 100, 1895.
The Mother Lode region of California : California State Min. Bur. Bull. 18,
154 pp., 1900.
Possibilities of the Mother Lode in depth : Min. & Sci. Press, Vol. 103, pp.
646-648, 1911.
Porcupine and the Mother Lode, Min. & Eng. Mag., Vol. 34, p. 448, 1911.
Possibilities of the Mother Lode in depth : Min. & Sci. Press, Vol. 105, pp.
459^62 1912.
(abst.) Eng. Index, 1912: pp. 387, 388, 1913.
The Mother Lode in Tuolumne Co.. Calif. : Min. & Sci. Press, Vol. 89, pp.
189, 210-211, 237, 257, 271-272, 306-307, 326-327, 343, 1904.
(abst.) G. Zentralbl, Vol. 6, p. 728, 1905.
Methods of mine timbering : Cal. State Min. Bur. Bull. 2, pp. 10, 24, 27, 33,
34, 46, 47, 62-66, 1896.
Milling Practice on the California Mother Lode : Min. & Eng. World, Vol.
32, pp. 3-5, 1910.
Types of Head Frames on the Mother Lode : Min. & Eng. World, Vol.
32, pp. 1213-1216, 1910.
Taylor, Bayard, Eldorado : Adventures in the path of empire, p. 110, New York,
1850.
Trask, J. B.- — Report of the geology of the Coast Mountains and part of the Sierra
Nevada, embracing the industrial resources of agriculture and mining : Senate
Doc. No. 9, 1854.
California State Geologist Fourth Ann. Rept., p. 60, 1856.
Tucker, W. B. — Mines and mineral resources of Amador County. Calaveras County,
Tuolumne County, 180 pp.. California State Min. Bur., 1914 ; Rept. XIV of the
State Mineralogist, pp. 3-172. 1915.
Mines and Mineral resources of the county of El Dorado. 37 pp., Cali-
fornia State Min. Bur., 1917 ; Rept. XV of the State Mineralogist, pp. 271-308,
1917.
Turner, H. W.— Mining on the Mother I^de (Cal.) : Min. & Sci. Press, Vol. 98,
pp. 40-^1, 1909.
The nomenclature of the feldspathic granolites : ,Jour. Geology, Vol. 8.
pp. 105-108, 1900.
The rocks of the Sierra Nevada : U. S. Geol. Survey Fourteenth Ann.
Rept., Pt. II, pp. 441-495, 1894.
Observations on Mother Lode gold deposits, California : ( In discussion
of paper of W. A. Prichard). Am. Inst. Min. Eng. Trans. (N. Y. meeting Oct..
1903) 2 pp.
MOTHER LODE GOLD BELT 219
U. S. Geol. Survey Geol. Atlas, Jacksou folio (No. 11), 1894.
Further contributions to the geology of the Sierra Nevada : U. S. Geol.
Survey Seventeenth Ann. Kept.. Pt. I, i)i). 521— 7<>2, 189(>.
Notice of some syenitic rocks from California : Am. Geologist. \'ol. 17,
pp. 379-:J86, 1896.
Turner, H. W., and Lindgren, Waldemar — U. S. Geol. Survey Geol. Atlas, Placer-
ville folio (No. 3), 1894.
Turner, H. W., and Ransome, F. L.- — U. S. Geol. Survey Geol. Atlas, Souora folio
(No. 41), 1897.
Tyson, P. T. — Geology and industrial resources of California, 74 pp., 1851.
Vanderburg, Wm. O. — Mining Methods & Costs at the Argonaut Mine, Amador
County, Calif. : U. S. Bur. of Mines, Information Circular 6311, Aug., 1930.
Von Bernewitz, M. W. — Metallurgy of the Calif. Mother I^ode : Min. Sci. Press,
Vol. 108. pp. 65-69, Jan. 3, 1914.
Whitney, J. D.— Geology of California, Vol. 1, pp. 482-483, 1865.
The auriferous gravels of the Sierra Nevada of California, pp. 34-39, 1880.
The auriferous gravels of the Sierra Nevada: Mem. Mus. Comp. Zool.
Harvard Coll., Vol. 6, 569 pp., 1879.
Winehell, A. N. — Studies in the mica group, II : Am. Jour. Sci., 5th ser., Vol. 9,
pp. 419-430, 1925.
Woakes, E. R. — Recent developments on the Mother Lode : Eng. & Min. Jour.,
Vol. 75, pp. 148-149, 1903.
Eng. Index, vol. 4, p. 576, 1906.
Wolf, J. H. G.— The Mother Lode of California : Min. & Sci. Press, Vol. 106, pp.
934-938, 983-986, 9 figs., 1913.
(abst.) Eng. Index, 1913: p. 380, 1914.
Woolf, Jesse A. (and Leaver, Edm. S.) U. S. Bur. of Mines Technical Paper 481
(Mother Lode tailings, re-treatment of).
also, same subject in U. S. Bur. of Mines Rept. on Investigation 2998,
April, 1930.
Woodwortih, Selim E. — Milling Methods and Costs at the Argonaut Mill, Jackson,
Calif. : U. S. Bur. of Mines Information Circular 6476, July, 1931.
Young. G. J. — Mining in the Mother Lode region of California : Eng. & Min. Jour.,
Vol. 118, pp. 64-66, 1924.
Gold mining at Carson Hill, Calif. : Eng. & Min. Jour., Vol. 112, pp.
725-729, 1921.
Mother Lode District of Califoi-nia still active : Eng. & Min. Jour., Vol.
121, pp. 696-697, Apr. 24, 1926.
DIVISION OP MINES PUBLICATIONS
PUBLICATIONS OF THE DIVISION OF MINES
During the past fifty-four years, in carrying out the provisions of
the organic act creating the former California State Mining Bureau,
there have been published many reports, bulletins and maps which go to
make up a library of detailed information on the mineral industry of
the State, a large part of which could not be duplicated from any other
source.
One feature that has added to the popularity of the publications is
that many of them have been distributed without cost to the public, and
even the more elaborate ones have been sold at a price which barely
covers the cost of printing.
Owing to the fact that funds for the advancing of the work of this
department have usually been limited, the reports and bulletins men-
tioned are printed in limited editions many of which are now entirely
exhausted.
Copies of such publications are available, however, in the offices of
the Division of Mines, in the Ferry Building, San Francisco; State
Building, Los Angeles; State Office Building, Sacramento; Redding;
and Division of Oil and Gas at Santa Barbara, Santa Paula, Coalinga,
Taft, Bakersfield. They may also be found in many public, private and
technical libraries in California and other States and foreign countries.
A catalog of all publications from 1880 to 1917, giving a synopsis of
their contents, is issued as Bulletin No. 77.
Publications in stock may be obtained by addressing any of the
above offices and enclosing the requisite amount in the case of publica-
tions that have a list price. Only coin, stamps or money orders should
be sent, and it will be appreciated if remittance is made in this manner
rather than by personal check.
Money orders should be made payable to the Division of Mines.
Note. — The Division of Mines frequently receives requests for some of the early
Reports and Bulletins now out of print, and it will be appreciated if parties having
such publications and wishing to dispose of them will advise this office.
II REPORT OF STATE MINERALOGIST
REPORTS
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•*E^rst Annual Report of the State Mineralogist, 1880, 43 pp.
Henry G. Hanks
••Second Annual Report of the State Mineralogist, 1882, 514 pp.,
4 illustrations, 1 map. Henry G. Hanks
••Third Annual Report of the State Mineralogist, 1883, 111 pp.,
21 illustrations. Henry G. Hanks
••Fourth Annual Report of the State Mineralogist, 1884, 410 pp.,
7 illustrations. Henry G. Hanks
••Fifth Annual Report of the State Mineralogist, 1885, 234 pp.,
15 illustrations, 1 geological map. Henry G. Hanks
••Sixth Annual Report of the State Mineralogist, Part I, 1886,
145 pp., 3 illustrations, 1 map. Henry G. Hanks
••Part II, 1887, 222 pp., 36 illustrations. William Irelan, Jr
•♦Seventh Annual Report of the State Mineralogist, 1887, 315 pp.
William Irelan, Jr
••Eighth Annual Report of the State Mineralogist, 1888, 948 pp.,
122 illustrations. William Irelan, Jr
••Ninth Annual Report of the State Mineralogist, 1889, 352 pp.,
57 illustrations, 2 maps. William Irelan, Jr
••Tenth Annual Report of the State Mineralogist, 1890, 983 pp.,
179 illustrations, 10 maps. William Irelan, Jr
Eleventh Report (First Biennial) of the State Mineralogist, for
the two years ending September 15, 1892, 612 pp., 73 illus-
trations, 4 maps. William Irelan, Jr $1.00 $0.20
••Twelfth Report (Second Biennial) of the State Mineralogist,
for the two years ending September 15, 1894, 541 pp., 101
illustrations, 5 maps. J. J. Crawford
••Thirteenth Report (Third Biennial) of the State Mineralogist,
for the two years ending September 15, 1896, 726 pp., 93
illustrations, 1 map. J. J. Crawford
Chapters of the State Mineralogist's Report, Biennial Period,
1913-1914, Fletcher Hamilton :
•♦Mines and Mineral Resources, Amador, Calaveras and Tuolumne
Counties, 172 pp., paper
Mines and Mineral Resources, Colusa, Glenn, Lake, Marin, Napa,
Solano, Sonoma and Yolo Counties, 208 pp., paper .50 .10
••Mines and Mineral Resources, Del Norte, Humboldt and Mendo-
cino Counties, 59 pp., paper
•♦Mines and Mineral Resources, Fresno, Kern, Kings, Madera,
Mariposa, Merced, San Joaquin and Stanislaus Counties,
220 pp., paper
♦♦Mines and Mineral Resources of Imperial and San Diego Coun-
ties, 113 pp., paper
••Mines and Mineral Resources, Shasta, Siskiyou and Trinity
Counties, 180 pp., paper
••Fourteenth Report of the State Mineralogist, for the Biennial
Period 1913-1914, Fletcher Hamilton, 1915 :
A General Report on the Mines and Mineral Resources of
Amador, Calaveras, Tuolumne, Colusa, Glenn, Lake, Marin,
Napa, Solano, Sonoma, Yolo, Del Norte, Humboldt, Mendo-
cino, Fresno, Kern, Kings, Madera, Mariposa, Merced, San
Joaquin, Stanislaus, San "Diego, Imperial, Shasta, Siskiyou
and Trinity Counties, 974 pp., 275 illustrations, cloth
Chapters of the State Mineralogist's Report, Biennial Period,
1915-1916. Fletcher Hamilton:
••Mines and Mineral Resources, Alpine, Inyo and Mono Counties,
176 pp., paper
Mines and Mineral Resources, Butte, Lassen, Modoc, Sutter and
Tehama Counties, 91 pp., paper .50 .05
•♦Mines and Mineral Resources, El Dorado, Placer, Sacramento
and Yuba Counties, 198 pp.. paper
Mines and Mineral Resources, Monterey, San Benito, San Luis
Obispo, Santa Barbara and Ventura Counties, 18.3 pp.,
paper .65 .10
**Mines and Mineral Resources, Los Angeles, Orange and River-
side Counties, 136 pp., paper
♦♦Mines and Mineral Resources. San Bernardino and Tulare
Counties, 186 pp.. paper
DIVISION OF MINES PUBLICATIONS III
REPORTS — Continued
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♦♦Fifteenth Report of the State Mineralogist, for the Biennial
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A General Report on the Mines and Mineral Resources of
Alpine, Inyo, Mono, Butte, Lassen, Modoc, Sutter, Tehama,
Placer, Sacramento, Yuba, Los Angeles, Orange, Riverside,
San Benito, San Luis Obispo, Santa Barbara, Ventura,
San Bernardino and Tulare Counties, 990 pp., 413 illus-
trations, cloth
Chapters of the State Mineralogist's Report, Biennial Period,
1917-1918, Fletcher Hamilton :
**Mines and Mineral Resources of Nevada County, 270 pp., paper-
Mines and Mineral Resources of Plumas County, 188 pp., paper_ ,$0..W .$0.10
Mines and Mineral Resources of Sierra County, 144 pp., paper .50 .10
Seventeenth Report of the State Mineralogist, 1920, 'Mining in
California during 1920,' Fletcher Hamilton ; 562 pp., 71
illustrations, cloth 1.75 .25
Eighteenth Report of the State Mineralogist, 1922, 'Mining in
California,' Fletcher Hamilton. Chapters published monthly
beginning with January, 1922 :
♦♦January, ♦♦February, ♦♦March, ♦♦April, ♦♦May, ♦♦June, July,
August, September, October, ♦♦November, December, 1922_ .25 .05
Chapters of Nineteenth Report of the State Mineralogist, 'Mining
in California,' Fletcher Hamilton and Lloyd L. Root.
January, February, March, September, 1923 .25 .05
Chapters of Twentieth Report of the State Mineralogist, 'Mining
in California,' Lloyd L. Root. Published quarterly. Janu-
ary, April, •♦July, October, 1924, per copy .25 .05
Chapters of Twenty-first Report of the State Mineralogist, 'Min-
ing in California,' Lloyd L. Root. Published quarterly :
January, 1925, Mines and Mineral Resources of Sacramento,
Monterey and Orange Counties .25 .05
April, 1925, Mines and Mineral Resources of Calaveras, Merced,
San Joaquin, Stanislaus and Ventura Counties .25 .05
July, 1925, Mines and Mineral Resources of Del Norte, Hum-
boldt and San Diego Counties .25 .10
♦♦October, 1925, Mines and Mineral Resources of Siskiyou, San
Luis Obispo and Santa Barbara Counties
Chapters of Twenty-second Report of the State Mineralogist,
'Mining in California,' Lloyd L. Root. Published quarterly :
♦♦January, 1926, Mines and Mineral Resources of Trinity and
Santa Cruz Counties
April, 1926, Mines and Mineral Resources of Shasta, San Benito
and Imperial Counties .25 .10
July, 1926, Mines and Mineral Resources of Marin and Sonoma
Counties -25 .05
♦♦October, 1926, Mines and Mineral Resources of El Dorado and
Inyo Counties, also report on Minaret District, Madera
County
Chapters of Twenty-third Report of the State Mineralogist, 'Min-
ing in California,' Lloyd L. Root. Published quarterly :
January, 1927, Mines and Mineral Resources of Contra Costa
County; Santa Catalina Island .25 .10
April, 1927, Mines and Mineral Resources of Amador and
Solano Counties .25 .05
July, 1927, Mines and Mineral Resources of Placer and Los
Angeles Counties -25 .10
October, 1927, Mines and Mineral Resources of Mono County — .25 .05
Chapters of Twenty-fourth Report of the State Mineralogist,
'Mining in California,' Lloyd L. Root. Published quarterly :
January, 1928, Mines and Mineral Resources of Tuolumne
County .25 .05
April, 1928, Mines and Mineral Resources of Mariposa County- .25 .05
July, 1928, Mines and Mineral Resources of Butte and Tehama
Counties .25 .05
October, 1928, Mines and Mineral Resources of Plumas and
Madera Counties .25 .05
Chapters of Twenty-fifth Report of the State Mineralogist, 'Mining
in California,' Walter W. Bradley. Published quarterly :
IV REPORT OF STATE MINERALOGIST
REPORTS — Continued
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** January, 1929, Mines and Mineral Resources of Lassen, Modoc
and Kern Counties ; also on Special Placer Machines
April, 1929, Mines and Mineral Resources of Sierra, Napa, San
Francisco and San Mateo Counties $0.25 $0.10
July, 1929, Mines and Mineral Resources of Colusa, Fresno and
Lake Counties .25 .10
October, 1929, Mines and Mineral Resources of Glenn, Alameda,
Mendocino and Riverside Counties .25 .10
Chapters of Twenty-sixth Report of the State Mineralogist,
'Mining in California,' Walter W. Bradley. Published
quarterly :
January, 1930, Mines and Mineral Resources of Santa Clara
County ; also Barite in California .25 .05
April, 1930, Mines and Mineral Resources of Nevada County ;
also Mineral Paint Materials in California .25 .05
July, 1930, Mines and Mineral Resources of Yuba and San Ber-
nardino Counties; also Commercial Grinding Plants in
California .25 .10
October, 1930, Mines and Mineral Resources of Butte, Kings
and Tulare Counties; also Geology of Southwestern Mono
County (Preliminary) .25 .10
Chapters of Twenty-seventh Report of the State Mineralogist,
'Mining in California,' Walter W. Bradley. Published
quarterly :
January, 1931, Preliminary Report on Economic Geology of the
Shasta Quadrangle. Beryllium and Beryl. The New Tariff
and Nonmetallic Products. Crystalline Talc. Decorative
Effects in Concrete .25 .10
April, 1931, Stratigraphy of the Kreyenhagen Shale. Diatoms
and Silicoflagellates of the Kreyenhagen Shale. Foraminif-
era of the Kreyenhagen Shale. Geology of Santa Cruz
Island .25 .10
July, 1931. (Yuba, San Bernardino.) Feldspar, Silica, Andalu-
site and Oyanite Deposits of California. Note on a Deposit
, of Andalusite in Mono County ; its occurrence and chem-
ical importance. Bill creating Trinity and Klamath River
Fish and Game District and its effect upon mining .25 .10
October, 1931. (Alpine.) Geology of the San Jacinto Quad-
rangle south of San Gorgonio Pass, California. Notes on
Mining Activities in Inyo and Mono Counties in July, 1931 .25 .05
Chapters of Twenty-eighth Report of the State Mineralogist, 'Min-
ing in California,' Walter W. Bradley. Published quarterly :
January, 1932, Economic Mineral Deposits of the San Jacinto
Quadrangle. Geology and Physical Properties of Building
Stone from Carmel Valley, Contributions to the Study of
Sediments. Sediments of Monterey Bay. Sanbomite .25 .10
♦♦April, 1932. Elementary Placer Mining Methods and Gold Sav-
ing Devices. The Pan, Rocker and Sluice Box. Prospect-
ing for Vein Deposits. Bibliography of Placer Mining
Abstract from April quarterly : Elementary Placer Mining
Methods and Gold Saving Devices. Types of Deposits.
Simple Equipment. Special Machines. Dry Washing.
Black Sand Treatment. Marketing of Products. Placer
Mining Areas. Laws. Prospecting for Quartz Veins.
Bibliography (mimeographed) .20 .05
July-October. (Ventura.) Report accompanying Geologic Map
of Northern Sierra Nevada. Fossil Plants in Auriferous
Gravels of the Sierra Nevada. Glacial and Associated
Stream Deposits of the Sierra Nevada. Jurassic and Cre-
taceous Divisions in the Knoxville-Shasta Succession of
California. Geology of a Part of the Panamint Range. Eco-
nomic Report of a Part of the Panamint Range. Acquiring
Mining Claims Through Tax Title. The Biennial Report
of State Mineralogist .50 .15
DIVISION OF MINES PUBLICATIONS V
REPORTS — Continued
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Chapters of Report XXIX, 1933 (quarterly) : titled "California
Journal of Mines and Geology," containing the following :
January-April. Gold Deposits of the Redding and Weavei'ville
Quadrangles. Geologic Formations of the Redding- Weaver-
ville District, Northern California. Geology of Portions
of Del Norte and Siskiyou Counties. Applications of
Geology to Civil Engineering. The Lakes of California.
Discovery of Piedmontite in the Sierra Nevada. Tracing
'Buried River' Channel Deposits by Geomagnetic Methods.
Geologic Map of Redding-Weaverville District, showing gold
mines and prospects. Geologic Map showing various mines
and prospects of part of Del Norte and Siskiyou Counties $0.80 $0.15
July-October. Gold Resources of Kern County. Limestone
Deposits of the San Francisco Region. Limestone Weath-
ering and Plant Associations of the San Francisco Region.
Booming. Death Valley National Monument, California.
Placer Mining Districts, Senate Bill 480. Navigable Waters,
Assembly Bill 1543 .80 .10
Chapters of Report XXX, 1934 (quarterly) : titled "California
Journal of Mines and Geology," containing the following :
January. Resurrection of Early Surfaces in the Sierra Nevada.
Geology and Mineral Resources of Northeastern Madera
County. Geology and Mineral Deposits of Laurel and
Convict Basins, Southwestern Mono County. Notes on
Sampling as Applied to Gold Quartz Deposits .40 .10
April-July. Elementary Placer Mining in California and Notes
on the Milling of Gold Ores .80 .10
Subscription, $1.50 in advance (by calendar year, only).
Chapters of State Oil and Gas Supervisor's Report :
Summary of Operations — California Oil Fields, July, 1918, to
March, 1919 (one volume) Free
Summary of Operations — California Oil Fields. Published
monthly, beginning April, 1919 :
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ber, ♦♦November, ♦♦December, 1919
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ber, October-November-December, 1930 Free
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ber. 19.31 Free
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15 — 4156
VI REPORT OF STATE MINERALOGIST
BULLETINS
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**Bulletin No. 1. A Description of Some Desiccated Human
Remains, by Winslow Anderson. 1888, 41 pp., C illustrations
♦♦Bulletin No. 2. Methods of Mine Timbering, by W. H. Storms.
1894, 58 pp., 75 illustrations
♦♦Bulletin No. 3. Gas and Petroleum Yielding Formations of Cen-
tral Valley of California, by W. L. Watts. 1894, 100 pp.,
13 illustrations, 4 maps
♦♦Bulletin No. 4. Catalogue of Californian Fossils, by J. G.
Cooper, 1894, 73 pp., 67 illustrations. (Part I was pub-
lished in the Seventh Annual Report of the State Mineral-
ogist, 1887)
♦♦Bulletin No. 5. The Cyanide Process, 1894, by Dr. A. Scheidel.
140 pp., 46 illustrations
♦♦Bulletin No. 6. California Gold Mill Practices, 1895, by E. B.
Preston, 85 pp., 46 illustrations
♦♦Bulletin No. 7. Mineral Production of California, by Counties,
for the year 1894, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 8. Mineral Production of California, by Counties,
for the year 1895, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 9. Mine Drainage, Pumps, etc., by Hans C. Behr.
1896, 210 pp., 206 illustrations
♦♦Bulletin No. 10. A bibliography Relating to the Geology, Pale-
ontology and Mineral Resources of California, by Anthony
W. Vogdes. 1896, 121 pp
♦♦Bulletin No. 11. Oil and Gas Yielding Formations of Los
Angeles, Ventura and Santa Barbara Counties, by W. L.
Watts. 1897, 94 pp., 6 maps, 31 illustrations
♦♦Bulletin No. 12. Mineral Production of California, by Counties,
for 1896. by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 13. Mineral Production of California, by Counties,
for 1897, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 14. Mineral Production of California, by Counties,
for 1898, by Charles G. Yale .'
♦♦Bulletin No. 15. Map of Oil City Fields, Fresno County, by
John H. Means, 1899
♦♦Bulletin No. 16. The Genesis of Petroleum and Asphaltum in
California, by A. S. Cooper. 1899, 39 pp., 29 illustrations
♦♦Bulletin No. 17. Mineral Production of California, by Counties,
for 1899, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 18. Mother Lode Region of California, by W. H.
Storms. 1900, 154 pp., 49 illustrations
♦♦Bulletin No. 19. Oil and Gas Yielding Formations of California,
by W. L. Watts. 1900, 236 pp., 60 illustrations, 8 maps__
♦♦Bulletin No. 20. Synopsis of General Report of State Mining
Bureau, by W. L. Watts. 1901. 21 pp. This bulletin con-
tains a brief statement of the progress of the mineral
industry in California for the four years ending December,
1899
♦♦Bulletin No. 21. Mineral Production of California by Counties,
by Charles G. Yale. 1900. Tabulated sheet
♦♦Bulletin No. 22. Mineral Production of California for Fourteen
Years, by Charies G. Yale. 1900. Tabulated sheet
**P>ullptin No. 23. The Copper Resoiiifes of California, by P. C.
DuBois, F. M. Anderson, J. H. Tibbits and G. A. Tweedy.
1002, 282 pp.. 69 illustrations. 9 maps _"_
♦♦Bulletin No. 24. The Saline Deposits of California, by G. E.
Bailey. 1902. 216 pp.. 99 illustrations. 5 maps
♦♦Bulletin No. 25. Mineral Production of California, by Counties,
for 1901, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 26. Mineral Production of California for the Past
Fifteen Years, h-^ Charles G. Yale. 1902. Tabulated sheet
DIVISION OP MINES PUBLICATIONS VII
BULLETINS— Continued
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♦♦Bulletin Xo. 27. The Quicksilver Resources of California, by
William Forstner. 1903, 273 pp., 144 illustrations, 8 maps
♦♦Bulletin No. 28. Mineral Production of California for 1902, by
Charles G. Yale. Tabulated sheet
♦♦Bulletin Xo. 29. Mineral Production of California for Sixteen
Years, by Charles G. Yale. 1903. Tabulated sheet
♦♦Bulletin Xo. 30. Bibliography Relating to the Geology, Paleon-
tology and Mineral Resources of California, by A. W.
Vogdes. 1903, 290 pp
♦♦Bulletin Xo. 31. Chemical Analyses of California Petroleum,
by H. X. Cooper. 1904. Tabulated sheet
♦♦Bulletin Xo. 32. Production and Use of Petroleum in Cali-
fornia, by Paul W. Prutzman. 1904, 230 pp., 116 illus-
trations, 14 maps
♦♦Bulletin Xo. 33. Mineral Productioii of California, by Counties,
for 1903, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 34. Mineral Production of California for Seven-
teen Years, by Charles G. Yale. 1904. Tabulated sheet —
♦♦Bulletin Xo. 35. Mines and Minerals of California, by Charles
G. Yale. 1904, 55 pp., 20 county maps. Relief map of
California
♦♦Bulletin Xo. 36. Gold Dredging in California, by J. E. Doo-
Uttle. 1905. 120 pp., 66 illustrations, 3 maps
♦♦Bulletin No. 37. Gems, Jewelers' Materials, and Ornamental
Stones of California, by George F. Kunz. 1905, 168 pp., 54
illustrations
♦♦Bulletin X'^o. 38. Structural and Industrial Materials of Cali-
fornia, by Wm. Forstner, T. C. Hopkins, C. Xaramore and
L. H. Eddy. 1906, 412 pp., 150 illustrations, 1 map
♦♦Bulletin No. 39. Mineral Production of California, by Counties,
for 1904, by Charles G. Yale. Tabulated sheet
♦♦Bulletin Xo. 40. Mineral Production of California for Eighteen
Years, by Charles G. Yale. 1905. Tabulated sheet
♦♦Bulletin Xo. 41. Mines and Minerals of California for 1904, by
Charles G. Yale. 1905, 54 pp., 20 county maps
♦♦Bulletin Xo. 42. Mineral Production of California, by Counties,
1905, by Charles G. Yale. Tabulated sheet
♦♦Bulletin Xo. 43. Mineral Production of California for X'ineteen
Years, by Charles G. Yale. Tabulated sheet
♦♦Bulletin X'o. 44. California Mines and Minerals for 1905, by
Charles G. Yale. 1907, 31 pp., 20 county maps
♦♦Bulletin X'o. 45. Auriferous Black Sands of California, by J.
A. Edman. 11X)7. 10 pp !___
♦♦Bulletin X^o. 46. General Index of Publications of the Cali-
fornia State Mining Bureau, by Charles G. Yale. 1907,
54 pp. ____
♦♦Bulletin X'o. 47.~ Mineral Production of California, by Counties,
1906, by Charles G. Yale. Tabulated sheet
♦♦Bulletin No. 48. Mineral Production of California for Twenty
Years, by Charles G. Yale. 1906
♦♦Bulletin Xo. 49. Mines and Minerals of California for 1906,
by Charles G. Yale. 34 pp
Bulletin X'o. 50. The Copper Re.sources of California, 1908, by
A. Hausmann, J. Kruttschnitt, Jr., W. E. Thome and J. A.
Edman. 366 pp., 74 illustrations. (Revised edition) $1.00 $0.25
♦♦Bulletin Xo. 51. Mineral Production of California, by Counties,
1907, by D. H. Walker. Tabulated sheet
♦♦Bulletin X^o. 52. Mineral Production of California for Twenty-
one Years, by D. H. Walker. 1907. Tabulated sheet
•♦Bulletin No. 53. Mineral Production of California for 1907,
with County Maps, by D. H. Walker. 62 pp
VIII REPORT OF STATE MINERALOGIST
BU LLETl NS— Continued
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•♦Bulletin No. 54. Mineral Production of California, by Counties,
by D. H. Walker, 1908. Tabulated sheet
♦♦Bulletin No. 55. Mineral Production of California for Twenty-
two Years, by D. H. Walker, 1908. Tabulated sheet
♦♦Bulletin No. 56. Mineral Production for 1908, with County
Maps and Mining Laws of California, by D. H. Walker,
78 pp.
♦♦Bulletin No. 57. Gold Dredging in California, by W. B. Wins-
ton and Chas. Janin. 1910, 312 pp., 239 illustrations, 10
maps
♦♦Bulletin No. 58. Mineral Production of California, by Counties,
by D. H. Walker. 1909. Tabulated sheet
♦♦Bulletin No. 59. Mineral Production of California for Twenty-
three Years, by D. H. Walker. 1909. Tabulated sheet
♦♦Bulletin No. GO. Mineral Production for 1909, with County
Maps and Mining Laws of California, by D. H. Walker.
94 pp.
♦♦Bulletin No. 61. Mineral Production of California, bv
Counties, for 1910, by D. H. Walker. Tabulated sheet___l
♦♦Bulletin No. 62. Mineral Production of California for Twenty-
four Years, by D. H. Walker. 1910. Tabulated sheet
**Bulletin No. 63. Petroleum in Southern California, by P. W.
Prutzman. 1912, 430 pp., 41 illustrations, 6 maps
Bulletin No. 64. Mineral Production for 1911, by E. S.
Boalich. 49 pp Free $0.05
Bulletin No. 65. Mineral Production for 1912, by E. S.
Boalich. 64 pp Free .05
♦♦Bulletin No. 66. Mining Laws of the United States and
California. 1914, 89 pp
•♦Bulletin No. 67. Minerals of California, by Author S. Eakle.
1914, 226 pp
♦♦Bulletin No. 68. Mineral Production for 1913, with County
Maps and Mining Laws, by E. S. Boalich. 100 pp
♦♦Bulletin No. 69. Petroleum Industry of California, with Folio
of Maps (18 by 22), by R. P. McLaughlin and C. A.
Waring. 1914, 519 pp., 13 illustrations, S3 figs. [18 plates
in accompanying folio.]
♦♦Bulletin No. 70. Mineral Production for 1914, with County
Maps and Mining Laws. 184 pp
♦♦Bulletin No. 71. Mineral Production for 1915, with County
Maps and Mining Laws, by Walter W. Bradley. 193 pp.
4 illustrations
♦♦Bulletin No. 72. The Geologic Formations of California, by
James Perrin Smith. 1916, 47 pp
♦♦Reconnaissance Geologic Map (of which Bulletin 72 is explana-
tory), in 23 colors. Scale: 1 inch = 12 miles. Mounted
♦♦Bulletin No. 73. First Annual Report of the State Oil and
Gas Supervisor of California, for the Fiscal Year 1915-16,
by R. P. McLaughlin. 278 pp., 26 illustrations ____
Bulletin No. 74. Mineral Production of California in 1916,
with County Maps, by Walter W. Bradley. 179 pp., 12
illustrations Free .15
♦♦Bulletin No. 75. United States and California Mining Laws.
1917, 115 pp., paper
Bulletin No. 76. Manganese and Cromium in California, by
Walter W. Bradley, Emile Huguenin, C. A. Logan, W. B.
Tucker and C. A. Waring. 19l8, 248 pp., 51 illustrations,
5 maps, paper $0.50 .10
Bulletin No. 77. Catalogue of Publications of California State
Mining Bureau, 1880-1917, by E. S. Boalich. 44 pp. paper Free .05
Bulletin No. 78. QuicksUver Resources of California, with a
Section on Metallurgy and Ore-Dressing, by Walter W.
Bradley. 1919, 389 pp., 77 photographs and 42 plates
(colored and line cuts), cloth 1.50 .35
Bulletin No. 79. Magnesite in California, by Walter W. Brad-
ley. 1925, 147 pp., 62 photographs, 11 line cuts and
maps, cloth 1.00 .10
DIVISION OF MINES PUBLICATIONS IX
BULLETINS— Continued
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fBulletin No. 80. Tungsten, Molybdenum and Vanadium in
California. (In preparation.)
fBulletin No. 81. Foothill Copper Belt of California. (In
preparation.)
•♦Bulletin No. 82. Second Annual Report of the State Oil and
Gas Supervisor, for the Fiscal Year 191&-1917, by R. P.
McLaughlin. 1918, 412 pp., 31 illustrations, cloth
Bulletin No. 83. California Mineral Production for 1917, with
County Maps, by Walter W. Bradley. 179 pp., paper Free $0.15
♦♦Bulletin No. 84. Third Annual Report of the State Oil and
Gas Supervisor, for the Fiscal Year 1917-1918, by R. P.
McLaughlin. 1918, 617 pp., 28 illustrations, cloth
♦♦Bulletin No. 85. Platinum and Allied Metals in California,
by C. A. Logan, 1919. 10 photographs, 4 plates, 120 pp.,
paper
Bulletin No. 86. California Mineral Production for 1918, with
County Maps, by Walter W. Bradley. 1919, 212 pp., paper Free .15
♦♦Bulletin No. 87. Commercial Minerals of California, with
notes on their uses, distribution, properties, ores, field tests,
and preparation for market, by W. O. Castello. 1920, 124
pp., paper
Bulletin Is'o. 88. California Mineral Production for 1919, with
County Maps, by Walter W. Bradley. 1920, 204 pp., paper Free .15
♦♦Bulletin No. 89. Petroleum Resources of California, with
Special Reference to Unproved Areas, by Lawrence Vander
Leek. 1921, 12 figures, 6 photographs, 0 maps in pocket,
186 pp., cloth
Bulletin No. 90. California Mineral Production for 1920, with
County Maps, by Walter W. Bradley. 1921, 218 pp., paper Free .15
Bulletin No. 91. Minerals of California, by Arthur S. Eakle.
1923, 328 pp., cloth $1.00 .15
♦♦Bulletin No. 92. Gold Placers of California, by Chas. S.
Haley. 1923, 167 pp., 36 photographs and 7 plates (colored
and line cuts, also geological map) , cloth
Bulletin No. 93. California Mineral Production for 1922, by
Walter W. Bradley. 1923, 188 pp., paper Free .15
♦♦Bulletin No. 94. California Mineral Production for 1923, by
Walter W. Bradley. 1924, 162 pp., paper
Bulletin No. 95. Geology and Ore Deposits of the Randsburg
Quadrangle, by Carlton D. Hulin. 1925, 152 pp., 49 photo-
graphs, 13 line cuts, 1 colored geologic map, cloth 2.50 .15
♦♦Bulletin No. 96. California Mineral Production for 1924, by
Walter W. Bradley. 1925, 173 pp., paper
♦♦Bulletin No. 97. California Mineral Production for 1925, by
Walter W. Bradley. 1926, 172 pp., paper
Bulletin No. 98. American Mining Law, by A. H. Ricketts,
1931, 811 pp., flexible leather 3.00 .15
Bulletin No. 99. Clay Resources and Ceramic Industry of
California, by Waldemar Fenn Dietrich. 1928, 383 pp., 70
photos, 12 line cuts including maps, cloth 1.50 .15
♦♦Bulletin No. 100. California Mineral Production for 1926, by
Walter W. Bradley. 1927, 174 pp., paper
♦♦Bulletin No. 101. California Mineral Production for 1927, by
Henry H. Symons. 1928, 311 pp., paper
Bulletin No. 102. California Mineral Production for 1928, by
Henry H. Symons. 1929, 210 pp., paper .25 .10
Bulletin No. 103. California Mineral Production for 1929, by
Henry H. Symons, 1930. 231 pp., paper .25 .10
Bulletin No. 104. Bibliography of the Geology and Mineral
Resources of California, to the end of 1930, by Solon Shedd 2.00 .15
♦♦Bulletin No. 105. Mineral Production in California for 1930
and Directory of Producers
Bulletin No. 106. Manner of Locating and Holding Mineral
Claims in California (with forms) .25
t Not yet published.
PHYSICAL SCIENCES LIBRARY
UNIVERSITY OF CALIFORNIA
DAVIS, CAUFORNIA 95616
k. REPORT OF STATE MINERALOGIST
BULLETINS— Continued
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Bulletin No. 107. Mineral Production in California for 1931
and Directory of Producers $0.25 $0.10
Bulletin No. 109. Oalifomia Mineral Production and Directory
of Mineral Producers for 1932, by Henry H. Symons, 200
pp. paper .25 10
DIVISION OF MINES PUBLICATIONS XI
PRELIMINARY REPORTS
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♦♦Preliminary Report No. 1. Notes on Damage by Water in Cali-
fornia Oil Fields, December, 1913. By R. P. McLaughlin,
4 pp.
♦♦Preliminary Report No. 2. Notes on Damage by Water in Cali-
fornia Oil Fields, March, 1914. By R. P. McLaughlin,
4 pp.
Preliminary Report No. 3. Manganese and Chromium, 1917.
By E. S. Boalich. 32 pp Free $0.05
♦♦Preliminary Report No. 4. Tungsten, Molybdenum and Vanad-
ium. By E. S. Boalich and W. O. Castello, 1918. 34 pp.
Paper Free .05
Preliminary Report No. 5. Antimony, Graphite, Nickel, Potash,
Strontium and Tin. By E. S. Boalich and W. O. Castello,
1918. 44 pp. Paper Free .05
♦♦Preliminary Report No. 6. A Review of Mining in California
During 1919. By Fletcher Hamilton, 1920. 43 pp. Paper
♦♦Preliminary Report IS'o. 7. The Clay Industry in California.
By E. S. Boalich, W. O. Castello, E. Huguenin, C. A.
Logan, and W. B. Tucker, 1920. 102 pp. 24 illustrations.
Paper
♦♦Preliminary Report No. 8. A Review of Mining in California
During 1921, with Notes on the Outlook for 1922. By
Fletcher Hamilton, 1922. 68 pp. Paper
MISCELLANEOUS PUBLICATIONS
•♦First Annual Catalogue of the State Museum of California,
being the collection made by the State Mining Bureau dur-
ing the year ending April 16, 1881. 350 pp
•♦Catalogue of books, maps, lithographs, photographs, etc., in the
library of the State Mining Bureau at San Francisco, May
15, 1884. 19 pp
♦♦Catalogue of the State Museum of California, Volume II, being
the collection made by the State Mining Bureau from
April 16, 1881, to May 5, 1884. 220 pp
♦♦Catalogue of the State Museum of California, Volume III, being
the collection made by the State Mining Bureau from May
15, 1884, to March 31, 1887. 195 pp
♦♦Catalogue of the State Museum of California, Volume IV, being
the collection made by the State Mining Bureau from
March 30, 1887, to August 20, 1890. 261 pp
♦♦Catalogue of the Library of the California State Mining Bureau,
September 1, 1892. 149 pp
♦•Catalogue of West North American and Many Foreign Shells
with Their Geographical Ranges, by J. G. Cooper. Printed
for the State Mining Bureau, April, 1894
••Report of the Board of Trustees for the four years ending Sep-
tember, 1900. 15 pp. Paper
Bulletin. Reconnaissance of the Colorado Desert Mining Dis-
trict. By Stephen Bowers, 1901. 19 pp. 2 illustrations.
Paper $0.10
Commercial Mineral Notes. A monthly mimeographed sheet,
beginning April, 1923 Free .15
XII REPORT OF STATE MINERALOGIST
MAPS
Register of Mines With Maps
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Register of Mines, with Map, Amador County $0.25 $0.05
Register of Mines, with Map, Butte County .25 .05
**Register of Mines, with Map, Calaveras County
•♦Register of Mines, with Map, El Dorado County
♦♦Register of Mines, with Map, Inyo County
♦♦Register of Mines, with Map, Kern County
♦♦Register of Mines, with Map, Lake County
♦♦Register of Mines, with Map, Mariposa County
♦♦Register of Mines, with Map, Nevada County
♦♦Register of Mines, with Map, Placer County
♦♦Register of Mines, with Map, Plumas County
♦♦Register of Mines, with Map, San Bernadino County
Register of Mines, with Map, San Diego County .25 .05
Register of Mines, with Map, Santa Barbara County (1906) .25 .05
♦♦Register of Mines, with Map, Shasta County
♦♦Register of Mines, with Map, Sierra County
♦♦Register of Mines, with Map, Siskiyou County
♦♦Register of Mines, with Map, Trinity County
♦♦Register of Mines, with Map, Tuolumne County
Register of Mines, with Map, Yuba County (1905) .25 .05
Register of Oil Wells, with Map, Los Angeles City (1906) .35 .05
OTHER MAPS
♦♦Map of California, Showing Mineral Deposits (50x60 in.)
♦♦Map of Forest Reserves in California
♦♦Mineral and Relief Map of California
♦♦Map of El Dorado County, Showing Boundaries, National Forests
♦♦Map of Madera County, Showing Boundaries, National Forests-
♦♦Map of Placer County, Showing Boundaries, National Forests
♦♦Map of Shasta County, Showing Boundaries, National Forests.
♦♦Map of Sierra County, Showing Boundaries, National Forests
♦♦Map of Siskiyou County, Showing Boundaries, National Forests
♦♦Map of Tuolumne County, Showing Boundaries, National Forests
♦♦Map of Mother Lode Region
♦♦Map of Desert Region of Southern California
Map of Minaret District, Madera County .20 .05
Map of Copper Deposits in California .05
♦♦Map of Calaveras County
♦♦Map of Plumas County
♦♦Map of Trinity County
♦♦Map of Tuolumne County
Geological Map of Inyo County. Scale 1 inch equals 4 miles .60 .05
♦♦Map of California accompanying Bulletin No. 89, showing gen-
eralized classification of land with regard to oil possibilities.
Map only, without Bulletin
Geological Map of California, 1916. Scale 1 inch equals 12
miles. As accurate and up-to-date as available data will
permit as regards topography and geography. Shows rail-
roads, highways, post offices and other towns. First geolog-
ical map that has been available since 1892, and shows geology
of entire state as no other map does. Geological details
lithographed in 23 colors. Unmounted .75 .05
Mounted 2.50 .15
♦♦Topographic Map of SieiTa Nevada Gold Belt, showing distribu-
tion of auriferous gravels, accompanying Bulletin No. 92.
In 4 colors (also sold singly)
DIVISION OF MINES PUBLICATIONS XIII
OTHER MAPS— Continued
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Geologic Map of Northern Sierra Nevada, showing Tertiary
River Channels and Mother Lode Belt, accompanying July-
October Chapter of Report XXVIII of the State Mineral-
ogist. (Sold singly) $0.25 $0.05
Map of Northern California, showing rivers and creeks which
produced placer gold in 1932 .20 .05
OIL FIELD MAPS
(Apply to Division of Oil and Gas, Ferry Building, San Francisco.)
XIV REPORT OF STATE MINERALOGIST
DETERMINATION OF MINERAL SAMPLES
Samples (limited to one at one time) of any mineral found in the
State may be sent to the Division of Mines for identification, and the
same will be classified free of charge. No samples will be determined if
received from points outside the State. It must be understood that no
assays, or quantitative determinations will be made. Samples should be
in lump form if possible, and marked plainly with name of sender on
outside of package, etc. No samples will be received unless delivery
charges are prepaid. A letter should accompany sample, giving locality
where mineral was found and the nature of the information desired.
INDEX
I'age
A&B Claim, Amador Oouiity 80, 117
Accident Claim, Amador County 80
Acknowledgments 11
Adams Gulch Mine, i<2l Dorado County 15, 48
Aden JNline, Amador County 106
Adjuster Mine, El Dorado County 15, 48
Aetna Claim, Amador County 60, 117
Alabama Mine, Tuolumne County 155, 174
Alameda Mine, Tuolumne County 156, 174
Alaska, B. C, Gold, Inc 1:18
Albion Cons., Tuolumne County 174
Alexander Mine, Calaveras County 141
Alphi ISIine, Amador County ^ 117
Alpine Claim, Amador County 59,117
Alpine Mine, El Dorado County 15, 48
Alpine Mine, PJl Dorado County (see Black Oak Mine) 20
Altaite 133
Amador Cons. Mine, Amador County . 101, 117
Amador County, analysis of gold production in 58
•black metal belt' in 58, 60
Calaveras (Carboniferous) rock in 57
early locations in__ 8
geography, climate, etc., of 125
geology of 55
gold and silver production of 59
Amador County mines and prospects on Mother Lode 117
A&B Mine
Aetna Mine
Alpine Mine
Amador Cons. Mine
Alphi Mine
Amador Gold and Amador Queen No. 1
Amador King
Amador Queen No. 2
Amador Star
Argonaut
Atlantic ,
Badger Mine
Ballard & JMartin Mine
Bay State .Mine
Bellwether Mine
Blue Jacket Mine
Boro Mine
Bf)na Fortuna
Bright ISIine
Brown Mine
Bryan IMine
Bunker Hill, Mayllower and Nevada
Burlington
Amador County mines iind lu-ospects on .Mollicr Lo<le 118
California
Casco
Caucasian Cons.
Centennial
Central Eureka
Chili Jim
Clyde
Clyde No. Extension
Comet
Cons. McNamara
Cosmopolitan, Dry Creek, Henry Clay
Crannis
Creek ledge
Creosus and St. Martin
Crown
DeSilvia
Dewitt
Dewitt Quartz
Dowling
Doyle
Dry Creek
East Keystone
Easton
lOclipse
El Dorado Mine
Elephantine
Empire
Empire
Eureka
(221)
222 INDEX
Page
Amador County mines and prospects on Mother Lode 119
Eureka No. 2
Evans
Excelsior
Extension
Farrell
Fort John
Forty Nine
Fremont
Giant
Golden Eagle
Golden Gate
Good Hope
Gover
Great "Western
Grey Eagle
Haley (Dewitt Nos. 1 and 2)
Haley Quartz
Hardenberg
Hartford
Hazard
Hector
Hercules
Herbertsville
Amador County mines and prospects on Mother Lode 120
Lucile
Mahoney
Mammoth
Marlotte
Maryland
Massa
Maxwell
May Ella
May Flower
Joe Davis
Kelly
Kennedy
Mclntyre
McKinney & Crannis
McKay & Love
Mechanics
Medean ,
Medean Cons.
Meek
Middle Bar
Middle Bar Q.M.
Little Illinois
Little Sargeant
Loyal or (Loyal Lode)
Keystone
Krueger & Vaughn
Lady Bedford
Last Chance
Law Lottier
Lincoln Cons.
Little Amador
Littlefield
Amador County mines and prospects on Mother Lode 121
Idaho Jr.
Illinois, Green et al.
Indiana
Italian
Jackson
Jackson Gate
Jackson G. M. & M. Co.
Middle Bar Group
Mineral Point
Monte DeOro
Montezuma
Monitor
Moore Mine
Morley Mine
Muldoon Mine
Murray, Vaughn, Kreiiger Mine
Mutual Mine
Nevill Mine
New Albany Mine
New London Mine
Niagara Mine
No. California
North Eureka No. 2
North Henry Clay
North Gover
North Star
Oaks Mine
Old Eureka Mine
INDEX 223
Page
Amador County mines and prospects on Mother Lode — Continued— __ _ 121
Tanner Tunnel, Alpha Mining Co.
Old Oakes
Onieda Mine
A-mador County mines and prospects on Mother Lode 122
Oneta Mine
Original Mine
Osceola Mine
Pacific Mine
Peerless Mine, Coulter, Homestake
Philadelphia Mine
Phoenix Mine
Pioneer Mine
Plymouth Cons.
Plymouth Eureka
Plymouth Rock Mine
Pocohantas Mine
Peclepovich Mine
Prize Mine
Providence Mine
Railroad Mine
Red Cloud Mine
Red Crown Mine
Red Oak Mine
Reese & Woolford
Reeves
Rhetta Mine
Richmond Mine
Sargeant & Marlotte
Seaton Mine
Shakespeare Mine
Sierra Mine
Amador County mines and prospects on Mother Lode ]23
Simpson & Aden
So. Cosmopolitan
Southerland
South Eureka
South Jackson
South Keystone
South Mahoney
South Mayflower
South Spring Hill including Madean & Talisman
Stewart
St. Julian
Stribley Mine
Sutter Creek Mine
Talisman Mine
Udy Mine
Valparaiso Mine
Venture Gold
Victoria Mine
Volunteer Mine
Wabash Mine
West Eureka Mine
Wetzler Mine
Wheeler Mine
White Mountain
Wildman Mine
Worley Mine
Wyomea Mine
Zeile (Zeila)
Amador Gold Mine, Amador County GO, 117
Amador King Mine, Amador County 117
Amador Metals Reduction Co 69
carbon de-activated by 193, 202
cyanide plant of 193
flotation sheet of 194
Amador Pacific Co 109
Amador Queen No. 1, Amador County (10, 117
Amador Queen No. 2, Amador County 60, 117
Amador Star Mine, Amador County 61, 117
American Institute of Mining Engineers, Transactions, cited 147
American Mine, El Dorado County 45
American seam mine. El Dorado County 45, 48
Analysis of concentrate from Sliger Mine .• 39
Analysis of gold production, Amador County 58
Calaveras County 126
Angels Iron Works, mill construction by 192
Angels Mine, Calaveras County 127
Anita Mine, Amador County 62
Ankerite, characteristics of 154
Ankeritization of greenstone 11, 55, 63, 84, 94
Anti-Chinese Mine, Tuolumne County 174
Antimony in Mother Lode ores 94, 213
Apatite in Kennedy Mine 90
Apex Claim, Calaveras County 128
224 INDEX
Page
App Mine, Tuolumne County 156, 174
costs at '. 157
Geology of 157
Arbona Mine, Tuolumne County 158, 174
Argentiferous gray copper 171
Argonaut Mine, Amador County 62, 117
costs at 69, 70
cyanidation tests at 195
dividends from 63
Eimco mucking machines in 66
geology of 63
history of 62
mining methods in 67
ore of 67
production of 62
screen analysis of mill pulp in 193
surface plant of 64
Argonaut Mine, El Dorado County 17, 48
Argonaut Mining Co 107
Arrastres, Mexican, early use of 8, 9
Arsenic in Mother Lode ores 197, 213
Arsenopyrite 34, 35, 39, 58, 60, 61, 83, 94, 97, 189
Ashburner, Wm., cited 93
Atlantic Mine, Amador County 117
Atlantic Q.M., Amador County 81
Atlas and Soldiers Gulch Claims 174
Atlas Mine, Tuolumne County 158
Bachman Mine, Calaveras County 143
Badger Claim, Amador County 101
Badger Mine, Amador County 117
Bald Hill Claim, Calaveras County 128
Ballard & Martin Mine, Amador Co 117
Ballard Mine, Amador County 70, 48, 117
Ballard-Plymouth Gold Mines Co 70
Bald Hill Mine, Calaveras County 128
Barr seam mine. El Dorado County 47
Bartlett Claim, Amador County 80
Barney Mine, Bl Dorado County 51
Bateman and Co 40
Bay State Mine, Amador Countv 71, 117
Bathurst Mine, El Dorado County 22, 48
Beaker Claim, Calaveras County 148
Bear Mountain Development Co 138
Beatrice Mine, Amador County 99
Beatty Claim, El Dorado County 46, 48
Beatty Mine, El Dorado County 44, 46, 48
Beebe Mine, El Dorado County 17
"cyaniding" flotation concentrate at 211
flow sheet of 209
Hadsell mill at 16, 207
mill of 207
open cut at 18
Bell Mine, Tuolumne County 158, 174
Bellwether Mine, Amador County 71, 117
Belmont Mine, Amador County 95
Belmont Osborne Mining Co 146
Belmont Shawmut Mine, Tuolumne County 162, 174
carbon de-activated in mills of 202
flotation at 193
flow sheet of 201
mill of 199
milling cost of 202
Bibliography on Amador County mines and prospects 117
El Doi^ado Countv inines and prospects 48
Mother Lode Gold Belt 214
Tuolumne County mines and prospects 174
Big Bonanza (see Oriole), Calaveras Countv 145
Big Chunk Claim, El Dorado County 1 19, 48
Big Chunk Mine, Tuolumne County 174
Big Four Claim, El Dorado Countv 19, 48
Big Sandy Claim, El Dorado County 19, 48
Big Sandy Mine, crystallized gold from , 19
Big Spring Claim, Calaveras County 128
Black Foot Mine, Tuolumne County 174
Black Hawk Mine, Tuolumne County 174
Black Hills Fremont Mines Co 83
'Black Metal Belt." in Amador County 58, 60, 97, 114
Black Oak Mine, El Dorado County 20
Black "Warrior Mine, Tuolumne County 177
Blasdel Seam Mine, El Dorado County 44, 48
Blue Jacket Mine, Amador Countv 117
Blue Lead Claims, El Dorado County 21, 48
Blue Rock Claim, El Dorado County 46, 48
Blair Cons. Mine, Calaveras County 148
Bona Fortuna Mine, Amador County 117
Bonanza Mine, El Dorado County 48
Boro Mine, Amador County 117
INDEX 225
Page
Boultler Mine, El Dorado County 21
Bovee (Sultana) Mine, Calaveras County 147
Bower Mine, Tuolumne County 175
Bown Mine, Tuolumne County 159, 174
Boyson Mine, Amador County 99, 114
Bradley, Walter W., cited 130, 132, 136, 203
Bright Mine, Amador County 62, 117
Brown Bird Mine, Tuolumne County 175
Brown Mine, Amador County 117
Brown Mine, Calaveras County 149
Diown-Smyth-Ryland Cons., Calaveras County 128
Browne, J. Ross, cited 95, 111, 129, 184, 186, 189
Bi'uner Mine, Calaveras t^)unt.\- 128
Kijant Claim, El Dorado County 25
Buena Vista Mine, Tuolumne County 175, 177
•lUill (luartz' vein li'!l, 137, 139, 14(1, 144, 14S, ir)3, 1511, 1(11, l(i5, 170, 171, 1S2
Hunlver Hill ]Mine, Amador County 56, 72, 117
Bimker Hill Mine, Amadoi' County, costs at 74
dividends from 72
history and production of 7
mine workings and geology of 7
mining and milling at 7
ore and concentrates of 7
Burch, Albert, cited 107
Burlington Mine, Amador County 117
Caetani, Gelasio, cited 197
Calaveras Claim, Cala\'eras County 135
Calaveras Cons. Mines. Calaveras County 135
Calaveras County, geogi-aphy, climate, water, power, timber of 125
geology of Mother Lode in 125
gold and silver production of 127
production, analysis of 126
Mariposa slate In 125
transportation in 126
Calaveras Mine, Calaveras County 129
Calaveras slate, in Amador County 57
in Calaveras County . , 125
in Mariposa County 181
in Tuolumne County . 153
Calaverite 133
Calcite, gold in. in Jumper Mine 168
California Claim, Amador County SI, 118
California Exploration Co. 31, 143
California Jack Mine, El Dorado County 48
California Mclntire Mining Co 99
California Miners' Assoc, cited 27
California Q. M., Amador County 81, 118
California Slimes Concentrating Co 84
Carboniferous rock.s, in Amador Count.v 57
in (r'alaveras County ^ 125
in Mariposa County 181
in Tuolumne County 153
Carbf)n in slate, reprecipitation or absorption of gold b.v 193
Cardinelle Mine, Tuolumne County 17,5
Carrington Mine. Tuolumne County 159, 179
Carrol Claim, El Dorado County 45, 49
Carson Hill Gold Mines Co 142
Carson Hill Mine, Calaveras County, arrastres at 9
Carson Hill mines, Calaveras County 129
flow sheet of 208
.geology of 124, 132
mill of 207
pi-oduction of 131
Castile Mine, El Dorado County 45, 48
(^asco Mine, Amador County 118
Caucasian <^ons. Mine, Amador County 118
Cedarbei-g Mine, El Dorado Count.v 4.1, 49
Centennial Claim, Amador Count\- 74, 118
Centennial Claim. Calaveras Count.v 151
Central Eureka Mine, Amador County 74, 118
costs at 204
c.vanidation tests at 195
dividends froin 75
How .sheet of 202
geology and ore-shoots of 77
licad frame of 76
history and production of 74
milling and ore characteristics of 80
mill of 202
tailing disposal at 203
telluride in 204
Central Eureka Mining Co 100, 102, 103, 112
Chalcopyrite 67, 90, 133, 169
Champion Mine, Mariposa County 183
Chantreau Mine, Tuolumne County 175
226 INDEX
Page
Chance Mine, Tuolumne County '. 175
Chaparral or Golden Queen Claim, El Dorado County 21, 49
Chaparrall Hill group, Calaveras County 137, 49
Chaparral Hill Operating Co 142, 149
Charley Mine, Tuolumne County 176
Cherokee Development Co 138
Cherokee Flat Mine, El Dorado County 49
Chicago Claim, Amador County 80
Chileno Mine, Tuolumne County 159, 175
Chili Jim Q. M., Amador County 81, 118
oji jj-jpg^ in in GTS 11
Chlorination at Mother Lode plants 10, 42, 115, 116, 193, 200
Church Mine, El Dorado County 21, 49
Church Union Mine, El Dorado County 21, 49
Cincinnati Mine, El Dorado County 22, 49
Clarke, P. W., cited 154
Classifiers, use of 193, 199
Climate of Amador County 58
Calaveras County 125
El Dorado County 14
Mariposa County 182
Tuolumne County 155
Clio Mine, Tuolumne County 159, 175
Cloudman Mine, Tuolumne County 175
Clyde No. Extension, Amador County 118
Clyde Mine, Amador County 118
Cobalt minerals in Pine Tree-Josephine veins 189
Coe Hill Mine (Gold Star or Bathurst), El Dorado Conuty 22, 49
Coffee Mill Mine, Tuolumne County 175
Cold Hill Claim, Calaveras County 128
Colloids, loss of gold in 197
Columbia Mine, Calaveras County 137
Combination Mine, Tuolumne County 175
Comet Mine, Amador County 118
Commodore Mine, Calaveras County 137
Coney Mine, Amador County 115
Confidence Mine, Calaveras County 149
Conner Seam Mine, El Dorado County 45
Connor Mine, El Dorado County 45, 49
Cons. McNamara Mine, Amador County 118
Conville Claim, Amador County 80
Conville Mine, Amador County 106
Cook Estate, Mariposa County 181, 183, 185
Copper minerals in Mother Lode ores 169, 171, 190
Cosmopolitan Group, Amador County 81, 118
Costs, early 9, 10
effect of World War on 11
milling 6, 9, 70, 85, 87, 141, 166, 192, 202, 204, 207
mining 17, 19, 40, 69, 70, 74, 85, 86, 87, 111, 115, 139, 141, 147, 150, 163
operating 34, 74,
87, 96, 105, 127, 135, 150, 151, 157, 161, 163, 166, 170, 184, 185, 189, 190
smelter, on concentrates 39, 142
Coulter Mine, Amador County 122
Covellite ^ 190
Cranes Gulch, or Wliitesides Mine, El Dorado County 45, 49
Crannis Mine, Amador County 118
Creek Ledge, Amador County SO, 118
Croesus Mine, Amador County 118
Crosston Seam Mine, El Dorado County 47
Crown Mine, Amador County 118
Crown Point and Gold Queen Consolidated, El Dorado County 23, 49
Crystalline Mine, Tuolumne County 160, 175
Cyanidation at Mother Lode plants
10, 42, 55, 69, 84, 135, 160, 193, 195, 197, 202, 203, 211
Dalmatia Mine, El Dorado County 23, 49
electric power at 10
Damourite in Kennedy Mine 89
Danaite 189
Darrow Mine, Tuolumne County 175
Davenport Mine, El Dorado County 21
Davenport Property, Bl Dorado County 21
Dead Horse Mine, Calaveras County 149
Demarest Mine, Calaveras County 128, 138
DeSilvia Mine, Amador County 118
Detert Estate Group, Amador County 80
DeWet Claim, Calaveras County 128
DeWitt Quartz Claim, Amador County 118
DeWitt Mine, Amador County 118, 119
Dividends from Mother Lode mines
63, 72, 75, S3, 86, 87, 92, 107, 113, 115, 135, 144, 150
Doctor Hill claims, Calaveras County 127
Dolling Gold Mining Co 145
Dowling Mine, Amador County 118
Doyle Mine, Amador County^ 118
Dry Creek Mine, Amador County 118
INDEX 227
Page
Dry Creek Q. M., Amador County 81
Duncan, Robt. J., cited 108
Dutch-App Mine, Tuolumne County, flow sheet of 198, 199
mill of 199
Dutch Mine, Tuolumne County 161, 175
Dynamite, introduction of 10
Dyneta Mine, Tuolumne County 176
Eagle Shawmut Mine, Tuolumne County 162
East Keystone Mine, Amador County 91, 118
East Mayflower Claim, Amador County 72
Eastern Star Claim, El Dorado County 51
Easton Mine, Amador County 118
Eclipse Mine, Amador County.^ 118
Economic Geology, cited 90
Eimco mucking machine, use of 66
El Dorado Mine (see Church), El Dorado County 21
El Dorado Claim, Amador County 82, 118
El Dorado Claim, Calaveras County 148
El Dorado County, geology of Mother Lode in 13
gold and silver production of 14
Mariposa slate in 13
El Dorado County mines and prospects on the Mother Lode 48
Adams Gulch
Adjuster
American Seam
Argonaut
Ballard & Martin
Bathurst
Beattie & Parsons
Blaisdel Seam
Big Chunk
Big Four
Big Sandy
Black Hawk
Blue Lead
Blue Rock •
Bonanza
California Jack
Carrol Seam
Castile Seam
El Dorado County mines and prospects on the Mother Lode 49
Cedarburg
Chaparral
Cherokee Flat
Church
Cincinnati
Coe Hill
Connor Seam
Cranes Gulch
Crown Point Cons
Dalmatia
Epley & Mammoth
Esperanza
Eureka
Falls
Fisk
French Hill
Frog Pond & Marigold Cons.
Garden Valley
George Seam
Georgia Slide
German
Golden Gate
El Dorado County mines and prospects on the Mother Lode 50
Golden State
Gold Mountain & Monitor
Gopher-Boulder
Grey Eagle
Grit Cons.
GriflSth
Gross No. 1
Guildford
Harmon Group
Hart Seam
Havilah
Hodge & Lemon Seam
Idaho
El Dorado County mines and prospects on the Mother Lode 51
Ida Livingston
Independence
Isabell
Ivanhoe, Williamatic, and Barney
Kelly
Kelsej-
Lady Emma (Currie)
LaMoile (Ophir)
16—4156
228 INDEX
Pa^e
El Dorado County mines and prospects on the Mother Lode — Continued 51
Larkin
Lincoln
Lone Jack
Lone Star
Lookout
Loveless
Lucky Jack
Lucky Marion
Mameluke
Manhattan Cons.
Manzanneta
Martinez
Mauley Seam
Mathenas Creek (Schneider & Co.)
McDowell & Wiltshire
Miller
Montezuma
Morning- Star, Lucky Girl, Eve. Star, Lucky Boy
Mountain Boy, Mountain Girl, Mountain Slide, Eastern Star
El Dorado County mines and prospects 52
Mulvey Point & Pacific
Nagler Seam
Nashville
New El Dorado
New Garabaldi (Oakland)
Ohio & Eagle (Sacramento)
Old Harmon
Old Judge
Olive
Ophir
Oriflamme (Ore Plem)
Orum
Pacific
Pacific Seam
Parsons Seam «
El Dorado County mines and prospects r>2
Pocahontas
Porphyry
Poverty Point
Rainbow
Reed & Keyser
Richelieu
River Hill
Rising Sun
Rose
Rosecranz
Rixford
Ryan
Sam Martin
School Girl
Selby
Sherman
Sleeping Beauty
Sliger
Smith Seam
Spanish Seam
Spanish Hill
Santa Claus
El Dorado County mines and prospects 54
Starlight
St. Clair
St. Lawrence
St. Lawrence Seani
Sun Rise
Superior
Swift & Bennett Seam
Taylor
True Cons.
Tunis
Uncle Sam
ITp-To-Date
Vandergrift
Van Hoolcer
Van
Waun Seam
Whiteside
Young Harmon
El Dorado County Mining and Development Co 37
El Dorado Mine (or Church Mines), El Dorado County 21
Electric power, introduction of 10
Elephantine Mine, Amador County IIS
El Rico Mining Co 150
Empire Company 106
Empire Mine, Amador County lis
Emeline Claim, Calaveras County 14S
INDEX 229
Page
Empress Josephine Mine, El Dorado County 28
Engineering and Mining Journal, cited 124, 197
Enterprise Claim, Calaveras County 129, 133
Epley & Mammoth Mine, El Dorado County 49
Erin-Go-Bragh & Cloudman Mines, Tuolumne Countv 175
Erythrite 189
Esperanza (Garden Valley) Claim, El Dorado County 23, 49
Etna King Mine. Calaveras County 151
Eureka Claim, El Dorado County. (See Harmon group.) 26, 49
Eureka Mine, Amador County 101, 118
Eureka No. 2 Mine, Amador County 119
Eureka No. 2 Q. M., Amador County 81
Eureka Vein, El Dorado County 17
Evans Mine, Amador County 119
Evening Star Claim, Calaveras County 128
Evening Star Mine, El Dorado County 51
Excelsior Mine, Amador County 119
Extension Mine, Amador County 119
Extension Claim, Calaveras County 135
Fairbanks, H. W., cited 115, 133, 146
Fairfax Claim, Calaveras County 151
Falls Mine, El Dorado County 24, 49
Farrell Mine, Amador County 119
Fellowcraft Mine, Calaveras County 138
Finnigan Mine, Calaveras County 139
Fisk Mine, El Dorado County 28, 49
Fisk or Porphyry Ledge, El Dorado County 45
'Flat veins' in Morgan Mine 129, 130, 133
Fleming Mine, Tuolumne Countv 175
Flotation at Mother Lode plants 29, 39, 61. 90, 193, 199, 200, 202, 204, 211, 212
Fluor-apatite in Kennedy Mine 90
Ford Mine, Calaveras County 139
tellurides in 139
Fort John Mine, Amador County 119
Forty Nine Mine, Amador County 11<4
Free Lode Mine, Tuolumne County I'ti
Fremont, Colonel John C 180, 186
Fremont Mine, Amador County 56, 82, 119
Fremont and Cover Mines, Amador County 82
dividends from 83
history and production of 82
mine workings and geology of S3
French Claim, El Dorado Countj^ 44
French Hill Mine, El Dorado County 47, 49
French or Nagler Claim, El Dorado County 45, 49
Frog Pond Mine, El Dorado County 49
Frue vanners 192
Galena 26, 29, 66, 67, 89, 90, 133, 169
Garden Valley Claim, El Dorado County 23, 49
Gem Mine, Tuolumne County 176
Geneva Mine, Amador County 91
Gentle Annie Mine, El Dorado County .37
Geography, climate, water, timber, power, in Amador County 58
climate, water, timber, power, in Calaveras County 125
climate, water, timber, power, in El Dorado County 14
climate, water, timber, power, in Mariposa County 182
climate, water, timber, power, in Tuolumne County 155
Geology of Mother Lode in Amador County 55
in Calaveras County 125
in El Dorado County 13.
in Mariposa County 181
in Tuolumne County 153
George Mine, El Dorado County 45, 49
George Seam Mine, El Dorado County 45
Georgia Slide Mine, El Dorado County 44, 46, 49
Georgia Slide, seam mines at 44, 46
German Mine, Bl Dorado County 49
Giant Claim, Amador County 80, 119
Gillis, J. A., Claim, Tuolumne County 159
Gladstone Mine, Tuolumne County 175
Golden Gate Mine, Amador County 119
Golden Eagle Mine, Amador County 119
Gold and Silver production of Amador County 59
of Calaveras County 127
of El Dorado County 14
of Mariposa County 182
of Tuolumne Countv 155
Gold Cliff Mine, Calaveras County 140
Gold Fields American Development Co 43
Gold, largest mass of, fi-om Morgan Mine 129
Gold Mountain Mine, El Dorado County 50
Gold production, analysis of, from Amador County 58
from Calaveras County 126
Gold .Star, El Dorado County 22
230 INDEX
Page
Golden Gate Mine, Calaveras County 137
Golden Gate (McNulty or Oakland) Mine, El Dorado County 24, 49
Golden Horseshoe Mining Corp 37
Golden Key Cons., Tuolumne County 175
Golden Nugget Mine, Tuolumne County 175
Golden Queen Claim, El Dorado County 21
Gold Ridge Mines, Inc., Tuolumne County 164, 175, 179
Golden Rule Mine, Tuolumne County 167, 175
Golden State Mine, El Dorado County 50
Golden Unit Mining Co 17
Good Hope Mine, Amador County 84, 119
Good Luck M & M Co., Tuolumne County 175
Gopher-Boulder Mine, El Dorado County 21, 24, 50
Gopher Mine, El Dorado County 21
Gould Mining Co 145
Governor Bradford Q.M., Amador County 81
Gover Mine, Amador County 82, 119
Graham Claim, Calaveras County 128
Grand Turk Mine, Tuolumne County 176
Granite State Claim, Amador County 8, 9
Granite State Company 92
Granite State Mine, Amador County 9, 99
'Gray ore,' deep mines in 11
Great Eastern Mine, Amador County 119
Great Western Claim, Calaveras County 141
Green, Et Al Mine, Amador County 121
Grey Eagle Claim, El Dorado County 19, 50
Grey Eagle Mine, Amador County 119
Griffith Consolidated, El Dorado County 25, 50
Grit Mine, El Dorado County 44, 46, 50
Gross No. 1 Mine, El Dorado County 50
Gross No. 1 and No. 2, El Dorado County. (See Harmon group) 26, 50
Gross Extension Mine, Tuolumne County 176
Guildford Mine, El Dorado County 36, 50
Gwin Mine, Calaveras County 11, 125, 141
costs at 141
dividends from 141
Hadsell Mill at Beebe Mine 16, 207
Hague, James D., cited 104
Hale Claim, Calaveras County 128
Haley & Wilbur Mine, Tuolumne County 176
Haley Mine, Amador County 119
Haley Quartz Mine, Amador County 119
Hamberger Mines 61
Hanks, Henry G., cited 129
Hardenberg Mine, Amador County 84, 119
Hardy Mine, Calaveras County 142
Harmon Group (includes Van Hooker, Young Harmon, Old Harmon, Gross No. 1
and No. 2 and Eureka), El Dorado County 26, 50
Harriman Mine, Tuolumne County 164, 176
Harris (see Oriole), Calaveras CJounty 145
Harris Mine, Tuolumne County 176
Hart Mine, El Dorado County 47, 50
Hartford Mine, Amador County 119
Harvard Mine, Tuolumne County 165, 176
Havilah (Nashville) Mine, El Dorado County 27, 50
Hayes Claim, Tuolumne County 164
Hazard Mine, Amador County 119
Hector Mine, Amador County 119
Henry Clay Mine, Amador County 118
Henry Clay Q.M., Amador County 81
Herbertville Claim 91, 119
Hercules Q.M., Amador County 81, 119
Heslep Mine, Tuolumne County 166, 176
Hessite 133
Hillside Group, El Dorado County 30
Hines-Gilbert Mine, El Dorado County 27
Hines Mine, El Dorado County 46
Hitchcock Claim, Tuolumne County 172, 176
Hodge and Lemon Mine, El Dorado County 47, 50
Hughes Cons. Mine, Tuolumne County 176
Homestake Mine, Amador County 122
Homestake Mine, Tuolumne County 176
Howe, Albion S., cited 78
Hulin, Carlton D., cited 90
Hydraulic mining in seam diggings 43, 44
Hydrothermal alteration of schists 8, 11, 55, 63, 84, 94
Idaho Jr. Mine, Amador County 121
Idaho Mine, El Dorado County 50
Ida Livingstone Claim, Bl Dorado County 28, 51
Idlewild Mine, El Dorado County 41
Illinois Mine, Amador County 121
Illinois Mine, Calaveras County 148
Imperial Gold Mines Company 159
Imperial Mine, Tuolumne County 176
Indiana Mine, Amador County 106, 121
INDEX 231
Page
Iowa Mine, Amador County 95
Iron Rock Mine, Calaveras County Z 129
Irvine Mine, Calaveras County 129
Isabel Claim, El Dorado County 28, 51
Isabella Mine, Tuolumne County 176
Italian Claim, Amador County 85, 121
Ivanhoe, Calaveras County 135] 51
Jackass Hill Mines, Tuolumne County [ I67
Jackson Exploration and Development Co 60
Jackson Flat Mine, Tuolumne County 176
Jackson Gate Mine, Amador County 121
Jackson G. M. & M. Co., Amador County 121
Jackson Gold Fields Co 60
Jackson Mine, Amador County 121
Jackson Mine, Calaveras County 149
Joe Davis Q. M., Amador County 81, 120
Johnson Claim, Calaveras County 128
Johnson vanners 192
Jolly Tar Mining Co., Calaveras County 142
Jones agricultural patent, Tuolumne County 164
Jones-Tarantula Mine, Tuolumne County 176
Josephine IVIine, Mariposa County ISO, 186
Jumper California Gold Mines Co 167
Jumper Claim, Calaveras County 148
Jumper Mine, Tuolumne County 167, 176
gold in calcite 168
Junction, important ore body at, in Central Eureka Mine 78
Justice Mine, Tuolumne County 176
Kelly Mine, Amador County 120
Kelly Mine, El Dorado County 29, 51
Kelly Mine, Tuolumne County 176
Kelsey Gold and Silver Mine, El Dorado County 29, 51
Kelsey Mine, El Dorado County, flow sheet of 210
mill of 211
Kennedy Extension Mining Co 63
Kennedy Mine, Amador County 11, 85, 120
carbon, effect of 205
costs at 85, 86, 87
cyanidation tests at 195
cyanide plant at 88
dividends from 86, 87
flotation at 204
geology and mine workings of 88
headframe of 86
mill of 89, 204
reagents in, for flotation 205
Kennedy Mining and Milling Co 115
Kentucky Mine, Calaveras County 129
Keystone Claim, Calaveras County 133
Keystone Mine, Amador County 91, 92, 120
antimonial sulphides in 94
arsenical sulphides in 94
dividends from 92
mine workings and geology of 92
Kirby, Alfred G., cited 143
Kirby Development Co., Calaveras County 143
Knopf, Adolph, cited 7, 63, 72, 83, 89, 98, 105, 132, 133, 140, 160, 162
Knox & Boyle Mine, Tuolumne County 169, 176
Kraut flotation unit in Kenndy mill 89
Kraut, Max, cited 204, 213
Krueger Claim, Amador County 95, 120
Lane, J. T., cited 171
Lady Bedford Mine, Amador County 120
Lady Emma (Currie) Mine. El Dorado County 51
LaMoile Mine, El Dorado County 51
Larkin Mine, El Dorado County 30, 51
Last Chance Claim, Calaveras County 133
Last Chance Claim, Tuolumne County 159, 176
Last Chance Mine, Amador County 120
Law Lottier Mine, Amador County 120
Lead and Tam O'Shanter Mine, Tuolumne County 177
Leaver and Wolf, cited 195
Lemon Claim, El Dorado County 28
Lemon Mine, El Dorado County 47
Lightner Mine, Calaveras County 143
dividends from 144
Lincoln Cons. Mines, Amador County 95, 120
costs at 96
geology and mine workings of 96
Lincoln Mine, El Dorado County 51
Lindgren, Waldemar, cited 87, 150
Little Amador Mine, Amador County 120
Little Gem Mine, Tuolumne County 177
Little Illinois Mine, Amador County 97, 120
Little Nugget Mine, Calaveras County 149
232 INDEX
Page
Little Sargent Mine, Amador Countj' 120
Littlefleld Mine, Amador County 120
Logan C. A cited _T6, 56, 64, 76, 202
Lone Jack Mme, El Dorado County 51
Lone Star Mine, El Dorado County 51
Lone Star Mine, Tuolumne County I77
Lookout Mine, El Dorado County 30 51
Lookout Mine, Tuolumne County '_ 177
Lopez Mining Co. 7q
"Los Mariposas" or Fremont Grant 180 ISl
I^ouisa Mine, Mariposa County [ ij^^
Loveless Mine, El Dorado County 51
Loyal or (Loyal Lode) Mine, Amador County I 120
Loyal Lode Mine, Amador County : 82, 83
Lucile Mine, Amador County 99' 120
Lucky Boy Mine, El Dorado County \ 51
Lucky Girl Mine, El Dorado Countv 51
Lucky Jack Mine, El Dorado County 51
Lucky Marion Mine, El Dorado Countv 30 51
McAlpine Mine, Tuolumne Countv " 16s' 177
McArdle Mine, Tuolumne Countv L 177
McCann Mine, Tuolumne County 177
McCauley Claim, Calaveras Countv l^i8
McCormick Mine, Tuolumne Countv 177
McDowell & Wiltshire Mine, El Dorado County 51
Mclntire Mine, Amador County i 99 120
McKinney & Grannis Mine, Amador Countv '. 120
McKay & Love Mine, Amador County 120
McMillan Mine, Calaveras County 129
McNulty Mine, El Dorado County 24
Mackenzie, Jolm H., cited " 189
Maclaren, Malcolm, cited 109
Madison Mine, Calaveras County 144
Mahoney Mine, Amador County 95, 120
Malachite 1 171
Maltman Mine, Calaveras Countv I 145
Malvina Group, Mariposa Countv 183
Mameluke Mine, El Dorado Countv 51
Mammoth Mine, Amador County." 97, 120
Mammoth Mine, Tuolumne Countv 168' 177
Manhattan Mine Cons., El Dorado Countv 51
Manzanneta Mine, El Dorado Countv ' 51
M. B. Sonora & Hayes Claims, Tuolumne Countv 164
Marigold Cons., Bl Dorado County 49
Mariposa County, Calaveras (Carboniferous) slate in 181
early locations in 8
foreword 180
Fremont Grant in ISO
geography, climate, water power, timber in 182
geology of 181
gold and silver production in 182
history of Mother Lode in ISO
Mariposa slate in 181
mills in 9
Mariposa Grant, Mariposa County {See also Tabulation, p. 189), mines on 186
Mariposa Mine, Mariposa County 9, 184
early mill at 9
first stamp mill on 184
Mariposa slate, deep mines in 11
in Amador County 55, 57
in Calaveras County 125
in El Dorado County 13
in Mariposa County 181
in Tuolumne County 153
reprecipitation by carbon of 193
Mariposite 13, 36, 38, 154, 157, 170
Mark Twain Mining Co 15S, 159
Marlette Mine, Amador County 120
Marshall (Sultana) Mine, Calaveras County 147
Marshall Claim, Calaveras County 148
Marshall, James 'V\^., early work by, on Gray Eagrle Claim 19
Martinez Mine, El Dorado County 30, 51
Martinusen Claim, Calaveras County 128
Maryatt Mine, Tuolumne County 177
Mary Harrison Mine, Mariposa County 185
Maryland Mine, Amador County 120
Massa Mine, Amador County 120
Mathenas Creek Mine (Schneider & Co.), El Dorado County 51
Mauley Mine, El Dorado County 45, 51
Mauley Seam Mine, El Dorado County: 1 45
Maxwell Mine, Amador County 120
May Ella Mine, Amador County 120
Mayflower Claim, Amador County 72, 120
Mayflower Mine, Amador County 117, 120
Mayon Claim, Amador County 82
INDEX 233
Page
Mazeppa Prospect, Tuolumne County 168, 177
Mechanics Mine, Amador County 120
Medean Mine, Amador County 91, 121
Meehan Cons. Mine, Amador County 121
Meek Mine, Amador County 121
Melones Cons. Mines, Calaveras County 133
Melones Mine, Calaveras County 129
Melones Mine, Calaveras County, costs at 135
dividends from 135
history of 133, 134
production of 135
Melonite 134
Merced Gold Mining Co 181, 183, 184, 185
Metallurgy on Mother Lode 191, 213
Metals Exploration Co 83
Mexican Claim, Calaveras County 135
Middle Bar Group, Amador County 121
Middle Bar Mine, Amador County 121
Middle Bar Q. M. Mine, Amador County 121
Middle Fork Mining Co 39
Miller & Holmes Mine, Tuolumne Countv 169, 177
Miller (Ribbon Rock) Claim, El Dorado County 31, 51
Mills, early stamp 9
Mineral Mountain, Calaveras County 133
Mineral Point Mine, Amador County 121
Mineral Resources of U. S. West of Rocky Mountains, cited 7, 95, 111, 129, 186
Mining and Metallurgy-, cited 204
Mohawk Mine, Calaveras Countv 145
Molybdenite 115, 133
Monitor Mine, Amador County 121
Monitor Mine, El Dorado County 50
Montezuma-Apex Mine, El Dorado County, costs at 34
cost in 207
flow sheet of 206
mill of 205
mining Co. 27
photo of 32
pulp-sifting cloth in 207
reagents in for flotation 207
Monteziima-Anex Mining Co 27
Montezuma Mine, Amador County 121
Montezuma Mine. El Dorado County 31, 51
Monte De Oro Mine, Amador County 121
Montreal Cons. Mine, Tuolumne County 177
Mooney Mine, Tuolumne County 177
Moore Mine. Amador County 98, 121
Morgan Mine, Calaveras County 129
Morgan Mine. Calaveras County, flat veins in 127, 130
geology and mine workings of 132
gold, large mass of, from 129, 130
history and production of 129
tellurides in 134
Morlev Mine, Amador County 121
Morning Star Mine. El Dorado County 51
Moss. Frank A., cited 124
Mother Lode, branching of, in El Dorado County 13
definition of 8
geologj' of. in Amador County 55
in Calaveras County 125
in El Dorado County 13
in Mariposa County 181
in Tuolumne County 153
history of 8
index map showing location of 10
view of, in Amador County 56
Mother Lode Mine. Tuolumne County 177
Mountain Boy Mine, El Dorado County 51
Mountain Democrat, cited 32
Mountain Oirl Mine, El Dorado County 51
Mountain Plide Mine, El Dorndo County 51
Mountain View Cons. Mine. Tuolumne Coimty 177
Mountain View Mine, Tuolumne County 177
Mucking machine, use of, in Argonaut Mine 66
Muldoon Mine, Amador County 121
Mulvey Point & Pacific Mine. El Dorado County 52
Murray Mine, Amador County 121
Mutual Mine, Amador County 121
Nagler Claim. El Dorado County 45, 52
Nashville Mine. El Dorado County 27, 52
arrastres at 9
Na.<!hville Mines, Ltd 31
Nevada Claim, .\mador County 72
Nevada Mine. Amador County 117
Nevada Wonder Mining Co 159
234 INDEX
Page
Nevill Mine, Amador County 121
New Albany Mine, Amador County 121
New Discovery Claim, Calaveras County 128
New El Dorado Mine, El Dorado County 52
New Era Mine, Tuolumne County 167, 177
New Garibaldi Mine, El Dorado County 52
New Grand Turk Mine, Tuolumne County 177
New London Mine, Amador County 81, 99, 121
Niagara Mine, Amador County 91, 121
Nickel 35, 134
North California Mine, Amador County 121
North Carolina Q.M., Amador County 81
North End Claim, Calaveras County 151
North Eureka Q.M. No. 2, Amador County 81, 121
North Extension, Maryatt Mine, Tuolumne County 177
North Gover Mine, Amador County 121
North Henry Clay Q.M., Amador County 81, 121
North Star Mine, Amador County 99, 114, 121
North Star Mine, Calaveras County 145
North Star Mine, Tuolumne County 177
Norwegian Mine, Tuolumne County 169, 177
tellurides in 169
Nut Pine Mine, Tuolumne County 177
Nyman Cons. Group, Tuolumne County 169, 177
O'Brien, T. S., cited 197
O'Donnell Mine, Tuolumne County 177
Oakland Mine, El Dorado County 24, 52
Oaks Mine, Amador County 106, 121
Occident Mine, Amador County 99
Ohio Mine, El Dorado County 52
O.K. North Extension, Tuolumne County 177
Old Brown-Smyth-Ryland Cons. Group, Calaveras County 128
Old Eureka Mine, Amador County 101, 121
costs at 101
geology of 103
headframe at 79
ore treatment at 204
underground scene in 100, 102
Old Harmon, El Dorado County (see Harmon Group) 26, 52
Old Judge Mine, El Dorado County 52
Old Oaker Mine, Amador County 121
Olive Mine, El Dorado County 52
Oliver-Harriman Mining Co., Ltd 164
Omega Table Mountain Mine, Tuolumne County 178
Oneida Mine, Amador County 111, 121
Oneta Mine, Amador County 122
Ophir Mine, El Dorado County 34, 51, 52
Ores of Tuolumne County 154
Oriflame Mine, El Dorado County 52
Orcutt Mine, Tuolumne County 178
Original Amador Company 8
Original Amador Mine, Amador County 104, 122
Original Amador Mine, Amador County, flow sheet of 196
mill of 197
mine workings and geology of 105
Oriole Mine, Calaveras County 145
Oro Fino Mine, El Dorado County 35
Oro Rico Mines Co 186
Orum Mine, El Dorado County 52
Orum Mining & Development Company, El Dorado County 35
Osborne Prospect, Calaveras County 146
Osceola Mine, Amador County 122
Outcropping ore-shoots, few early ones profitable 9
Pacific Claim, Tuolumne County 166, 178
Pacific Coast Gold Mines Corporation 157, 161, 167
Pacific Mine, Amador County 106, 122
Pacific Mining Co 15, 17, 181, 186, 187, 212
Pacific Quartz Mine, El Dorado County 35, 52
Pacific Seam Claim, El Dorado County 46
Pacific Seam Mine, El Dorado County 52
'Paint' sulphide, in Argonaut Mine 67
Palmer, Cook & Co 184
Parallel Mine, Tuolumne County 176
Parsons Claim, El Dorado County 46, 52
Patterson Mine, Tuolumne County 170, 178
Peerless Mine, Amador County 111, 122
Pefion Blanco Mine, Mariposa County 178, 185
Perry, P. R., cited 203
Pet Cossey Mine, Tuolumne County 178
Petzite 133, 168, 169
Phoenix Mill Site, Amador County 106
Philadelphia Mine, Amador County 122
Phoenix Mine, Amador County 106, 122
Pine Tree Claim, Tuolumne County ^_____^__, 159, 178
INDEX 235
Page
Pine Tree and Josephine Mines, Mariposa County 186
cost in 189
flow sheet of 212
geology of 188
mill of 213
mine workings of 187
reagents used for flotation 213
section across 188
Pine Tree Mine, Mariposa County 180, 186
Pioneer Chief Mine, Calaveras County 146
Pioneer Claim, Amador County 62, 63, 85
Pioneer Claim, Calaveras County 128
Pioneer Mine, Amador County 106, 122
Pitchblende 14V
Placerville Gold Mining Co 26, 35
Pleasant Ridge Co S, 92
Plymouth Eureka Mine, Amador County 122
Plymouth Mine, Amador County 106, 122
cyanidation tests at 195
dividends from 108
equipment of 111
geology of 107, 108
history of 106
main ore-shoot of 110
mill of 195
milling cost at 197
veins and ore-shoots of 109, 110
Plymouth Rock Mine, Amador County 122
Pocahontas Mine, El Dorado County 36, 53
Pocahontas Q.M., Amador County 81, 122
Poclepovich Mine, Amador County 122
Porphry Mine, El Dorado County 45, 53
Port Arthur Claim, Calaveras County . 148
Potosi, Amador County 81
Poverty Point (Guildford) Mine, El Dorado County 36, 53
Power in Amador County ;_- 58
in Calaveras County 125, 126
in El Dorado County 14
in Mariposa County 182
in Tuolumne County 155
Price, Thomas, cited 35
Prince Prospect, Calaveras County 148
Princeton Mine, Mariposa County 180
production of 189
Prize Mine, Amador County 122
Procter & Gamble Company 190
Production of mines on Mariposa Grant (tabulation) 189
Providence Q.M., Amador County 81, 122
Pyrophyllite in Kennedy Mine 89
Quaker City Mine, Calaveras County 146
Quartz, massive outcrop of 129, 137, 148. 153, 182
Queen Specimen Mine, Mariposa County 186
Railroad Mine, Amador County 122
Rainbow Mine, El Dorado County 53
Rancheria Mine, Amador County 72
Ranchoree Mine, Amador County 72
Rappahannock (jlaim, Tuolumne County 171, 178
Raspberry Mine, Calaveras County 149
Rathgeb Mine, Calaveras County 147
pitchblende in 147
Rawhide Mine, Tuolumne County 171, 178
Rawhide Mine No. 2, Tuolumne County 178
Raymond. R. "W., cited 93, 111
Red Cloud Mine, Amador County 122
Red Crown Mine, Amador County 122
Red Oak Mine, Amador County -. 122
Reed & Keyser Mine, El Dorado County .' 53
Reese Mine. Amador County 106, 122
Reeves Claim. Amador County 80
Relief Mine. Calaveras County 129, 135
Relief & surplus Mine, Tuolumne County 178
Republican Mine, Tuolumne County 178
Reitz Group. Tuolumne County 179
Reserve Claim, Calaveras County 133
Reserve Mine, Calavera.*? County 129, 133
Rhetta Mine, Amador County 61, 122
Ribbon Rock (see Miller). El Dorado County 31
Rice Claim. Tuolumne County 159, 179
Richelieu Mine. El Dorado County 53
Richmond Mine, Amador County 122
Rickard. T. A., cited 147
Rising Star Mine, Amador County 106
Rising Sun Mine, El Dorado County 53
River Hill Group (Includes Gentle Annie Mine), El Dorado County 37
River Hill Mine. El Dorado County 53
River Tunnel Mine, Mariposa County 186
236 INDEX
Page
Riverside et al., Mine, Tuolumne County 179
Rizford Mine, EI Dorado County 53
Robin Rock Claim, El Dorado County 31
Romagg-i Claim, Calaveras County 128
Rosecranz Mine, El Dorado County 53
Rose Mine, El Dorado County 53
Ryan Mine, El Dorado County 53
Sacramento Bee, cited 16, 34
Sacramento Mine, El Dorado County 52
Sam Martin Mine, El Dorado County 53
Santa Claus Mine, El Dorado County 53
Santa Cruz Claim, Calaveras County, open-cut on 131, 136
Santa Cruz Mine, Calaveras County 129, 131, 135
Santa Ysabel Group, Tuolumne County 169, 179
Santissima Claim, Tuolumne County 159, 179
Sarah Francis Mine, Tuolumne County 179
Sargent & Marlotte Mine, Amador County 122
'Schist ore,' deep mines in 11
School Girl Mine, El Dorado County 53
Selby Mine, El Dorado County 53
Screen analysis of mill pulp at Argonaut Mine 193
Seam diggings 43
mines in El Dorado County 43
Seaton Mine, Amador County 111, 122
Senator Mine, Tuolumne County, flow sheet of 211
mill of 212
for flotation, reagents used 213
Senator Mining Co., Tuolumne County 172
Shakespeare Mine. Amador County 122
Shaw & ShoUer Mine, Tuolumne County 179
Shawmut et al. Mines, Tuolumne County 179
Sherman Mine, El Dorado County 38, 53
Shotgun Mine, Calaveras County 147
Side Hill Mine, Tuolumne County 174
Sierra Mine. Amador County 122
Silliman, B., cited 42
Silver, high values in A^Tiitford vein of Heslep Mine 166
Silver Production of Amador County 55
of Calaveras County 127
of El Dorado County 14
of Mariposa County 182
of Tuolumne County 155
Simpson Mine, Amador County 106, 123
Skinner, Joseph (Fisk) Mine, El Dorado County 28
Sleeping Beauty Mine, El Dorado Countv 53
Sliger Mine, El Dorado Countv 38, 46, 53
Smith Mine, El Dorado County 45, 53
Smith Seam Mine, El Dorado County 45
Smyth Claim, Calaveras County 128
Sobrante Mine, Tuolumne County 179
Sonora Claim 164
South Carolina Mine, Calaveras County 134
South Cosmopolitan Q. M., Amador County 81, 123
South Eureka Mine, Amador Countv 77, 111, 112, 123
costs at 112, 113
dividends from 113
geology and mine workings 113
history and production of 111
operations of, in Hardenburg mine 84, 111
South Jackson Mine, Amador County 114, 123
South Keystone Cons. Mining Co., Amador County 114, 123
South Lincoln Claim, Amador County 95, 123
South Mahoney Claim, Amador County 95, 123
South Mayflower Mine, Amador Countv 72, 123
South Sliger Claim, El Dorado County 39
South Spring Hill Mine.' Amador County 91, 123
Southerland Claim, Amador County-; 106, 123
Spanish Hill Mine, El Dorado County 53
Spanish Dry Diggings 44, 46, 47
Spanish Mine, El Dorado County 47, 53
Sphalerite 90, 115
Spiers, James, cited 80
Springfield Mine, El Dorado 22, 42
Spring Gulch Claim. Calaveras County 128
Spring Hill Mine, Amador County 9, 91
early mill at 9
St. Clair Mine, El Dorado County 54
St. .Tulian Mine. Amador Countv 123
St. Lawrence Mine, Calaveras County 128
St. Lawrence Mine. El Dorado County 40, 47, 54
St. Lawrence Seam Claim. El Dorado County 47, 54
St. Martin Mine. Amador County 118
Stamp mills, advantages of 191
early 9
use of, on Mother Lode 191
INDEX 237
Page
Stanford, George, early stamp-mill construction by 191
Stanislaus Claim, Calaveras County 133
Stanislaus Mine, Calaveras County, tellurides in 133
Star Light Mine, El Dorado County 54
State .Mineralogist Reports, cited 42, 83, 88, 115, 129, 130. 133, 142, 150, 202
State Mining Bureau reports, cited 7, 80, 83, 115, 139, 141, 189
Steam power, use of 10
Stewart Mine, Amador County 95, 123
Stevens & Brown Claim, Calaveras County 135
Stevens Claim, Calaveras County 135
Stinchfield jNIine, Tuolumne County 179
Stickles Mine, Calaveras County 149
Stocker Mine, Tuolumne County 159, 179
Storms, Wm. H., cited 61, 87, 159, 185, 189
Strengite in Kennedy Mine . 90
Street Mine, Tuolumne County 179
Stribley Mine, Amador County 12:!
Sultana Mine, Calaveras County 147
Summit IMine, Amador County 74, 123
Sunrise Mine, El Dorado County 41, 54
Superior (Tin Cup) Mine, El Dorado County 41, 54
Sutter Creek Mine, Amador County 123
Sweeney Mine, Tuolumne County 179
Swift & Bennett Claim, El Dorado County 47, 54
Sylvanite 133
Talisman Mine, Amador County 91, 123
Tanner Tunnel (Alpha Mining Co.), Amador County 121
Tarantula jMine, Tuolumne County 173, 179
Tarantula Hawk Mine, Tuolumne County 179
Tavlor (Idlewild) Mine, El Dorado County 41, 54
Tellurides 133, 134, 139, 169, 204
Tetradymite 134
Tetrahedrite G7, 133
Thorne Mine, Calaveras County 148
Thorp Mine, Calaveras County 143
Timber in Amador County 58
in Calaveras County 125, 12f.
in El Dorado County 14
in Mariposa County 182
in Tuolumne County 155
Tin Cup jNIine, El Dorado County 41
Toledo Cons. Mine, Tuolumne County 177, 179
Tollgate Prospect, Calaveras County 148
Tonopah Belmont Mining Co 162
Tonopah Mining Co 161
Trio Mine, Tuolumne County 179
Transportation in Calaveras County 126
Tuolumne County 155
Trask. John B., cited 7, 92, 101
Treasure Mine, Amador County 56
classifiers used in 199
flow-sheet of 200
mill of 199
Triple Lode Mine, Calaveras County 148
Tucker. W. B., cited 105
Tullis Mine, El Dorado County 54
Tulloch Mine, Calaveras County . 149
Tulloch vanners 192
Tuolumne County, geography, climate, water, timber in 155
geology of 153
gold and silver production of 155
greater proportion of sulphides in ores of 154
list of mines in or near Mother TiOde 174
Tuolumne County mines on or near Mother Lode 174
Alabama Mine
Alameda Mine
Albion Mine Cons.
Anti-Chinese
App
Arbona
Atlas and Soldiers Gulch Mine
Bell Mine
Belmont Mine
Belmont Shawmut
Big Chunk
Blackfoot and Side Hill
Black Hawk Mine
Bower Mine
Bown Mine
Brown Bird Mine
Buena Visata Mine
Cardinelle
Chance
Chantreau
238 INDEX
Page
Tuolumne County mines on or near Mother Lode — Continued 174
Chileno
Clio
Cloudman Mine
Tuolumne County mines on or near Mother Lode 175
Coffee Mill
Combination
Crystalline
Darrow
Dutch
Eagle Shawmut
Erin-Go-Bragh & Cloudman
Fleming
Gladstone
Golden Key Cons.
Golden Nugget
Gold Ridge Mining Co.
Golden Rule
Good Luck M & M Co.
Tuolumne County mines on or near Mother Lode 176
Grand Turk
Gross Extension
Harriman
Harris
Harvard
Heslep
Hitchcock
Homestake
Hughes Cons. & Dyneta
Imperial
Isabella & Gem
Jackson Flat & Parallel
Jones Tarantula
Justice
Kelley & M. Lode
Knox & Boyle
Last Chance, Free Code, Charley
Haley & Wilbur
Lead & Tarn O'Shanter, Toledo Cons.
Buena Vista
Little Gem
Lone Star
Look Out
Mammoth
Maryatt
No. Ext Maryatt
Mazepa
McAlpine
McArdle
McCann
McCormick
Miller & Holmes
Montreal Cons.
Mooney
Mother Lode
Mountain View Cons.
Mountain View
New Era
New Grand Turk
North Star, Black Warrior, Yellow Jacket
Norwegian
Nut Pine
Nyman Cons.
O'Donnell
O. K. & No. Ext.
Tuolumne County Mines on or near Mother Lode 178
Omega Table Mountain
Omega & West Ext.
Orcutt
Pacific
Patterson, Lennon
Pena Blanco
Pet Cossey
Pine Tree
Rappahannock
Rawhide
Rawhide No. 2
Relief & Surplus
Republican
Tuolumne County Mines on or near Mother Lode 179
Rice
Riverside Et Al
Santa Tsabel Cons.
Santissima
Sarah Francis
Shawmut Et Al.
Shaw & Sholler
INDEX 239
Tuolumne County mines on or near Mother Lode — Continued 179
Sobrante
Stinchfield
Stocker
Street
Sweeney
Tam O'Shanter
Tarantula
Tarantula Hawk
Tarantula-Gold Ridge-Reitz Group
Toledo
Trio
Valparaiso
Victoria
Vulture
Whiskey Hill
Wickam
Willieta
Wilson & Means, Rice, Stocker, Gillis & Carrington
Wise
Tuolumne Giant Gold Mines Co 164
Turner, H. W., cited 189
True Cons. Mines, El Dorado County 54
True Consolidated Mining & Milling Co 26
Tyro Mine, Mariposa County 190
Udy Mine, Amador County 123
Uncle Sam Mine, El Dorado County 54
Union Consolidated Co., El Dorado County 15
Union Mine, El Dorado County, airastres at 9
U. S. Bureau of Mines reports, cited 11, 195, 197, 203
U. S. Commissioner of Mineral Statistics, cited 7, 95, 111, 129, 186
U. S. Geological Survey reports, cited 7, 83, 98, 108, 115, 132, 139, 154
Union Mine, Calaveras County 129
Union (Springfield) Mine, EI Dorado County 22, 42
Up-to-date Mine, El Dorado County 54
Uraninite 147
Utah-Apex Mining Co 33
Utica Mine, Calaveras County 149
Utica Mining Co. 141, 144
Valparaiso Mine, Amador County 114, 123
Valparaiso Mine, Tuolumne County 179
Van Hooker Claim, El Dorado County (See Harmon group) 26, 54
Van Mine, El Dorado County 54
Vandergrift Mine, El Dorado County 54
Vanners, early form of 19
for concentration 192
horsepower required for 69
introduction of 10
Vaughn Claim, Amador County 95, 120
Veerkamp, Robert, Prospect, El Dorado County 37
Venture Gold Mine, Amador County 123
Victoria Mine, Amador County 123
Victoria Mine, Tuolumne County 179
Virginia Mine, Mariposa County 181, 190
operating cost of 190
Volunteer Mine, Amador County 123
Vulture Claim, Tuolumne County 166
Vulture Mine, Tuolumne County 179
Wabash Mine, Amador County 123
War Eagle Claim, El Dorado County 43
Washington Mine, Calaveras County 149
Water in Amador County 58
in Calaveras County 125, 126
in El Dorado County 14
in Mariposa County 182
in Tuolumne County 155
Water power, use of 10
Waterman Prospect, Calaveras County 151
Waun Mine, El Dorado County 47, 54
Webster Claim, Amador County 81
Webster Mine, Tuolumne County 168
Wells property, Calaveras County 143
West American Consolidated Gold Mines 61, 71
West Eureka Mine, Amador County 123
Wetzler Mine, Amador County 123
Wheeler, J. T., cited 8
Wheeler, Lieut. George M., cited 40
Wheeler Prospect, Amador County 59, 123
Whiskey Hill Mine, Tuolumne County 165, 179
White Mountain Mine, Amador County 123
Whiteside Mine, El Dorado County 45, 54
Whitney, J. D., cited 7
Wickam Mine, Tuolumne County 179
Wildman Mine, Amador County 95, 123
Willieta Claim, Tuolumne County 164, 179
Willimantic Mine, El Dorado County 51
Wilson & Means Claim, Tuolumne County 159, 179
240 INDEX
Page
Wilson, E. 'W. & R. J., partnership 20
^\'inters Mine, Calaveras County 147
Wise Claim, Tuolumne County 173, 179
Woodside Claim, El Dorado County, early form of vanner at 19
Woodside Claim, El Dorado County (see Beebe Mine) 17
Woolford Mine, Amador County 106
World War period, effect of, on costs 11
Worley Claim, Amador County 81, 123
Worley Mine, Amador County 123
Wyomea Mine, Amador County 123
Yellow Jacket Mine, Tuolumne County 177
Young Harmon Claim, El Dorado County (see Harmon (Irfiup) 26, 54
Zeila Mine, Amador County 115,123
dividends from 115
geology and mine workings of 115
Ziegler Claim, Calaveras County 151
Zincblende 115
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