Are Om 8 = o> om 9a @ jee em ay rd tit ate te beds ry ty as tie i at ite a - : rf ee ‘ eae ratbate ve ois Alt, rn pe ne ets 3 ee Vi ete nde edtireti tal efeys tet) e+ eile anh rt on ee | 4 +f 7 arerksararac hs reel etaraa? . fe elelelaets erclé ‘fee sale i at SULA sat ale false dla relaresoteejele cits eis erei i 4 ih i . i andahiet ee SSO NN . ist? se We eee i +?) . wae 7 eat istcait ; Bans . si a i tate ae . eine die é se . r in bt : t v aie . bine “f ae itt aly t if ‘i itt Hh WEEN soit hy ort i a rare sith ‘ i ot ed iltehitinins ite ue 74 sare talaraperes é teeatetatiteds iat i rasa +19) ats . “4 | ak hy ete se ty rete " itis ee eis Mie OU ‘e se is sit Eiaatlh ue iit Wee 4 ee es tt a vi i th ath rer tt +4) is ue ah ee wis ap u i ee wile ayes] H, prays {. be 4 ‘ sett ae 4° b wd by ii hist reas ois) se ponarnyt $29) ae i i. . nl eats eb +f y Leth TT The Sete Tbe ie coe i i t cent i a it 2 “ a ace re ele: ‘ is rt asta th Heats hs DORR ty POR tH 219.9) seit! teeth relate! . felettte! ye “a Nis, atl EY ea 4 Neat ' it if uA iit $ii5 - 4; . sats ‘ i ‘ Hun Reimrnoe T ao itt ‘ Le aTtrht when telert ee eee . these Uae ata eesarey ‘ fails} ART } Ea ee iPr9i9,94)¢ th +18 A%9, se) Ag iy bi be ne ny oats -~ > - eel ws 4 7t . | “8 . WH mb ye vit: eh REA a a° 3 se s+. oe . Sin 82 On BSOw~ eos oe ‘ 3 iy ith SHsesaeal i itu ttt aia sha Maa ase Ua i sa _ DEPARTMEN - OF’ THE INTERIOR “GEORGE OTIS Sure, DIRECTOR z CLASSIFICATION OF THE PUBLIC LANDS BY GEORGE OTIS SMITH AND OTHERS “WASHINGTON “GOVERNMENT PRINTING OFFICE : 1913 vu ‘UNITED: STATES GEOLOGICAL SU RVEY co Sees A DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIREcTOR BULLETIN 537 THE CLASSIFICATION OF THE Prgic LANDS. <2 BY GEORGE OTIS SMITH AND OTHERS WASHINGTON GOVERNMENT PRINTING OFFICE 1913 D. CF D, APR 17 1918 A009. Y/22/) The purpose of land classification_____- Development of the Survey’s organizatio CONTENTS. m for land classification_—______—~— Euctory and legal basis for land classification... = 0-2 = _4_-- inieerneulon so) ose Se MBN ESIIN ie ee General divisions__..__-___.-_.__ Peblictang laws 2.2 ..-____~ Agricultural-land laws ____ Prrpeee oo kee ee Homesteads ____---—-- Forest homesteads —___ Enlarged homesteads__ Desers Jand>2-- > Reclamation act __---_- ~bemlated. traets._.....- itumnber sand. stone. lands) oie) marti ela a Seeger Mineral-land laws —_.._---_ CS EE Ae a a Podlland Inws 2222. S2.2l.2 Laws relating to public and quasi-public uses______________ eet PU ARID URES Cartes, Ses ee ee Bie ison? “Wa epee oe Mining and milling —__ Municipal uses_______- CS eo) a re ee Grants: to. States... ...~.- In aid of schools and State institutions______.________ fp. aid of internal improvements... 2232.0 oieul. Prog ACE = b. 2e e Geiicead. rants... .. Necessity for land classification___ Agencies and methods of classification Classification by affidavit of applicant_________________________ Rascsmicaiion. Dy deptity Surveyors. 2.6242 Classification by Land Office fie Classification by the Geological Historical sketch»... Ts | a re OU ee eee ee 1% Phosphate lands __________ PGINRI SGA 2s Par eervyaceo) arid ast ay OR oer eas ce re ee a a a 20 bo we pw to SH SH ON r Pee a a a 4 CONTENTS. History and legal basis for land classification—Continued. Agencies and methods of classification—Continued. Classification by the Geological Survey—Continued. Page. Water-power sites (0 7." "Ua eee ees Un Cee 41 FROSCTVOET SUCES 2 8 a I a he ie 42 Public “waiter: PeServes:. 20 2225 See eee een ere oa oe, 42 Withdrawal acts.2.- 2242.00) 2 Rees a ea eee ee es ree 43 Separation sactSsci 4. feet go8 ey) Y og) es oe ee 45 Desirable new legislation: =28 05. bie Se ee ee eee . 46 Classification. of mineral lands 62220 eee 50 Hield methods 220.0. ee ee 50 Development. o.oo a ee 50 Detailed survey... 5 ee 53 Methods used when a topographic base is available________ a Methods used when a base map must be prepared__________ 54 Methods followed when the Land Office survey affords a base mapec 0 ae 58 Reconnaissance. survey... — =. sya) Sere a eee 60 Publie-land” Surveys. bse. o os ee a 61 Preparation of data. for. classification. — 332 ether bik)? eee 63 Goal . land's 922 3a Be he a ee ee 65 Purpose..of classification... shac\. ae Re eee ea 65 Methods of ‘classification. 2.23 25 = eayat ee ene ee ee 66 Principles. involved 2-52... Sees sore i irene ee 66 Factors. involved 253 4). ee 2 ee 67 Hssentials of: workability 22.22) oc ees eee 67 Quality 2.7252 2 ee a i aa a a eee 68 TRICKNESS - oo ee a ee 69 Depth. 2a a i cee 73 Classification by 40-acre tracts:.or, lois 242) Se eee 78 Outerop coal andi burned: coal si gtw: <= iieles sae Te ee 78 Metheds of valuation. 22 ee eee 79 Cost of coal an, the grounds os eee ei ee 79 “a ctorey Ivo we eo ae 8 81 Liffect, of quality. on price. <= wie Giles. Siphe eeee eS e 82 Effect of mining: cost, of price... Sheu Hin eins yee 82 Value. of. thin coals.) ee ee SS ee ee 83 Value-of irresular beds. 0s eas Futile eee 87 Value. persacteciciahd At nies. ppc Hiei eh ee ae 90. Reduction for deptheseiee2t ii) ieee ey iebey ee ee ee 91 Allowance for. fanlusi (2505 sce se ee ee 93 Effect of IntTusions. 23222 ee See ee ee eee ee ee 94 Allowance for other factors______-____ mt) Seer ye 2) Rae 94 Reduetion for. distance rom) Tratlrogde 233 teen Tels sabe 95 Maximum... prices 222th. i canpitie Tia) RO pe ee eee ee 95 Review .of classification. 22a see 9 Fence ie Sait See ae 95 Regulations for the classification and valuation of public coal Lami a he ee a ake eee eee ed 96 Resto ma tty s ee Cn ot ee gees eS. er 97 Hield .work..on Coal: lami ses 2 ee ee epee ee 98 General nature. of the work 22352222 ee a ees Ie ee 98 TiO CATION «yt oe ee eh a 99 - Stra Lierreen iy, oe te Ss es ee 99 Extent and thickness of coaliheds iba sie ee 100 CONTENTS. Classification of mineral lands—Continued. Coal lands—Continued. Field work on coal lands—Continued. A MMinde and cepth of thevecudiae.. = ee Popeaeiiys OL. CWE COL ee Tee meneame a Mee ee eet = Peer OL Midler ial eo ee ee cn ht ee Procedure in classification and valuation. — 2 Erocress in classification ang valuation." Poe a CL Et SMa TG Stan eceeaiaaaln doa alld al Re ela Bel hy ao ec Biel eR oe Kin miiireniees Or Toll AMO! ast eet eee 2 NE Pe? PirssvireatOun Or ell and pas Vand Dg ELST Sac linea illite es dp eye ei i a A al Sol PLS F6 pay 1 lalalaliii ial I a Le a ee Pe reniratiiins PNOSOMate 2 oo ee ee eee Ege POSE TAY Clg trot ee eee nn ee Settee Aare PN ae TLIC Saati SS) 2 aa iis ease lel i ut dh alah pao a al (ESO R I ACIIERS tig (1 Seated taper eit, OE ala na sa Pimiaey Of PHOSpaate SiLgation. So ote ee Pee OM. OF iOS priate: UsanGs eon ke oe eee ee 1 UE ST ELST SO) ACE! 2 pcm te al a al Rete a Nae dete Rec re Prieiples controlling “classitication= 2 98 DEC H eo ct na ll dae et at tok ete tf Polat dle eee tt Aes teee lOn et Te eek Taiesepearine potash and’ related salines__U_o2 02.2 ee amore Occurrence of the deposits: eo Digeeimeation Of potash-bearing lands. ee Miscellaneous nonmetalliferous mineral lands_____________________ Metalliferous mineral lands_______.._ cts etiaa No § ,5ncrete linoed tid ioe Ren. Rees a Re a ea EST! ig (3 12 Ral it te a ea a a Ear OL “ela esinicaiiOnl = thee ea rane est EGO fee, Yee te in Pn ee ee Sa Toe CLA, ot a Re ee a ee a ae PT ee Cae eee ea LE UCAS Toe RM @ fo ot, 01 een rete Whine eee Pe Cee Ee ee ee OC wRIt ste GuOOP nA yMiy eo em fuvesticatvion of-placer-"deposits.__2 205 SEES SR U8 11s en Ae Se, SRC ere ae tee llpe CPU ger etal eh ar RESTS Cy gato. are cs CPS 5 a a Spare ae CIDVGsbIeahiOM Ol elOGe OCeCDOSIES. 22 2.2 oo a Rings fF @yiaence Avalaple 3 RROnieee eee y . 2 Ske Oe A Oe nk pee carpe SATE) OS Nee ah es ee Pirasions and metamorphism... 0 gee cee OTE So SS Ses a es Be Ee Ber Ginmrons sme tool wr lodges. Ge LE SE SR MR) 2S oe ne car ES Deer Terpeens tart SUNGry Gece ee a Presi TIE ROPIGN LE agi 8 By-pragucts. of mineral-land. classification... 0. 2 Value ot collateral information, obtained... --§ Data of direct interest to the public at large__________________ Date Telawne kG prospecting and mining... 2. PT SEC 0 EE ee Ga cane Te) amen a ne oe 6 CONTENTS. Page Classification in -relation. ta: water. nesourees 222 eee 159 General...prineiples...of. water , wtilizatiens 22 ee ee ee Classification, of, water-power Sile@S=2 22a ae ee eee ee 161 Preliminary ‘withdrawals_-_ = ct Sa ee 161 Methods of field examination_____________ pee SSCs, AS IER Rear re 167 Diversity, of GOmGiL OI oo op 167 Reconnaissance examination. 20-5 ee es 168 Detailed field: tnvestigutions.__ 2. _ 2 ee Li Compilation of results and revision of withdrawals____________ 174 Adverse. claims. 22 220142 ee ee a ee Nonpower. classification.._._-___ 2 eee 176 Additional requirements to make power classification effective-__ 177 Classification of lands as rerards. irrigabiliiy «25. 2 ee 178 Hheld methods. 2.5 es ese ee a ee 178 General. cotisideratious 2522 0k ue ee eee 178 Available. swater: SUDDIY 223 6 te 181 Present utilization of water for irrigation_________________ 182 Duty of water. ee ee 183 Character of lands to be irrigated_________________ pe ee 184 Character of irrigation WwOrke. =: 2-2 ke ee 185 Methods of Classification... 3a.) 2 A ee 185 Procedure. under the Carey. ACh... 22 sos 185 Irrigation |‘ TeSeryoir, SifGS = S22 one ee 187 Procedure under the enlarged-homestead acts__--_---____-- 187 Classification as regards domestic uses. 2-2 eee 190 General - principles 2. ee eee 190 Farm ‘waters: Supply a.2204 2280 3 ee 180 Range water: supply. <2" eee 191 Municipal water supply...) 2 ss ee ee 193 TRO oo a ee ee ee ee 193 ILLUSTRATIONS. Page. Fieure 1. Township map showing classification and valuation of coal lands. a ee ee ee 63 2. Diagram showing split or broken coal beds and their value for classification! 6 eee ee TE 3. Diagram showing depth limits of coals of different B. t. u. and of different thicknesses under 6 feet__-__-___-__-_-------- 76 4. Rates paid in the United States for mining coal of specified thicknesses, and curve showing average relation between mining rate. aiid “EHRICKMeSSs <2" Se ee eee 85 5. Sketch map showing lines along which a coal bed is of equal thickness (isopachous lines), drawn for use in the valuation OL Goal Fear en a er ee ee 89 6. Reduced copy of diagram used by the United States Geological Survey in computing tonnage and value of coal per acre____ 92 7. Diagram showing depth to which phosphate ey are classi- fied ‘under ‘the recwla tions. ee eee 152 8. Typical township card from survey records illustrating action taken by the United States Geological Survey on power sites. 166 THE CLASSIFICATION OF THE PUBLIC LANDS. By Grorce Otis Smiru and others. THE PURPOSE OF LAND CLASSIFICATION. In the latter half of the nineteenth century the spirit of the public- land laws in the United States was settlement and development. With a public domain of one and a third billion acres, acquired in the preceding half century—1803-1853—by purchase, discovery, explora- tion, and cession, and with another. third of a billion acres in Alaska constituting a later purchase, the Nation felt that it could be lavish with its lands. The wilderness called for pioneers of every type, and large premiums were held out to capital enterprise and individual initiative. Development was desired whatever the cost in lands that were intrinsically of little value without settlement. The same cen- tury that saw the creation of this national domain—an-empire in itself—also witnessed the distribution of more than one-half of its acreage. ‘This shrinkage of the national domain has naturally been coincident with national development in all lines of industry. West- ern prairies have become the world’s granary, and western moun- tains, once wholly in public ownership, are now contributing to their private and corporate owners the profits on no small proportion of the world’s output of metals and of mineral fuels. With advancing years a wise nation, like a prudent man, learns _ to husband its resources. Land values are now recognized, the pur- pose in both legislation and administration has changed, and highest development alone is sought. With the most and the best of the Nation’s land already alienated, the national duty is to put to its best use what remains. Utilization of lands for their greatest value necessitates the detcr- mination of that value, which is, briefly, land classification; and, to be adequate, land classification must be based upon first-hand acquaintance with the particular land under consideration. With a national estate including country ranging from salt-incrusted deserts to valleys knee-deep with nutritious grasses or giant forests almost impenetrable because of luxuriant undergrowth, no general statutes ij 8 CLASSIFICATION OF THE PUBLIC LANDS. that may be enacted can be made so definite as not to require the exercise of well-informed judgment in their execution. To this end examination and classification of the public lands constitute an initial step in their disposition for development and settlement. That a few decades ago settlement and development commonly outstripped clas- sification and often far preceded even the legal disposition of the land itself is no good reason for failure to follow the more logical pro- cedure now. } The principle of land classification is inherent in many of the public-land laws, and classification of lands has in late years been specifically recognized by Congress as a step indispensable to the ad- ministration of the national domain. This public estate is even now so extensive and valuable as to demand a business policy. Making allowance for the alienated lands included within the land units de- scribed in the various coal-land areas withdrawn by executive order for classification, and also estimating the expected reduction of these withdrawals by classification of parts of them as noncoal land, the people of the United States possess to-day 44,000,000 acres of coal lands, exclusive of the Alaskan coal fields. A large proportion of this acreage, however, is underlain by the lower-grade coals. In the almost equally important items of oil and phosphate rock the exist- ing withdrawals indicate national ownership of over 2,000,000 acres of oil and gas lands and nearly 3,000,000 acres of lands which will furnish our agricultural regions their future supply of mineral phos- phate. Nor have all the agricultural lands been alienated. Public and private irrigation projects will reclaim several millions of acres of arid land, and dry farming under the enlarged-homestead act will materially add to the area of farm lands. To insure appropriate disposition and to secure highest use of the Nation’s lands, scientific land classification by the United States Geological Survey has been made an integral part of public-land administration. Quantitative knowledge of the land and its re- sources is now made a preliminary, first, to disposition of lands under the various settlement and development laws; second, to reser- vation of lands from present acquisition pending the enactment of adequate legislation; and third, to valuation of lands under a statute which provides for their disposition at prices expressing known value. The purpose of land classification, then, is highest utilization, and to attain this end it has been necessary to coordinate the work of scientific investigation with the administrative functions of the Department of the Interior. The large participation of the Geo- logical Survey in the public-land administration has naturally pre- sented problems involving changes both in office and field organiza- tion and in executive and scientific methods. For these changes PURPOSE OF LAND CLASSIFICATION. 9 there has been little or no precedent. Scientists and public men of older countries have been outspoken in their interest in this new application of science to governmental administration, and requests have been made for more detailed information on the subject than is available in the references appearing in administrative reports of the Secretary of the Interior and his subordinates. A new application of any branch of science necessarily affects the science itself. New use involves added requirements and in turn may contribute in by-products even more than it demands. The general effect of this direct application of the Geological Survey’s investiga- tive work to large problems of public administration is believed to have been beneficial to science itself. It has broadened the outlook of the investigator, but especially it has demanded that results be sought which are quantitatively exact as well as qualitatively true. A full statement of the policy of land classification and a detailed description of the procedure and methods-so far found necessary to carry out that policy, in the stage of development already reached, are presented in this bulletin. This information is believed to be of value both to students of government and to geologists and engineers interested in the application of scientific investigation to practical business. The historical and legal phases of the discussion may be of greatest interest to the citizen concerned in his country’s highest development, while the description of field methods should be of immediate value in indicating new requirements imposed upon sci- entific education, for details of this business policy of the Govern- ment are already being adopted in private and corporate land exam- inations. This bulletin represents contributions by many authors—members of the land-classification board and of the field branches of the Sur- vey. The description of the development of the Survey’s organiza- tion for land classification, which immediately follows this introduc- tion, was written by W. C. Mendenhall, who as chief of the land- classification board has been directly responsible for the preparation of the bulletin. The discussion of the history and legal basis of classification was prepared by M. W. Ball, a geologist who has been identified with the work of land classification from its beginning and is now chairman of the oil section of the board. | . The chapter on the classification and valuation of coal land was written by G. H. Ashley, until recently State geologist of Tennessee and now the chairman of the coal section of the land-classification board. At the time of his earlier connection with the Survey Mr. Ashley, who has made a special study of coal problems in both the eastern and the western fields of the United States, wrote the chapter on “ The value of coal land” which appears in Survey Bulletin 424. In the preparation of the present paper Mr. Ashley has been most 10 CLASSIFICATION OF THE PUBLIC LANDS. efficiently assisted by C. E. Lesher, who is independently responsible for the short section on “ The preparation of data for classification.” Mr. Lesher should be credited with many of the office methods which facilitate the prompt and accurate handling of data contributed by the field men of the Survey. Field methods are discussed by E. G. Woodruff, C. H. Wegemann, R. W. Richards, and F. R. Clark, all of whom are members of the geologic branch and have had wide experience in field work leading up to land classification. Under the topic “ Oil and gas lands,” J. D. Northrop, who has had experience in the California oil fields, and _C. H. Wegemann, a geologist of broad experience in the Rocky Mountain fields, have collaborated in the discussion of the geologic occurrence of oil and gas, while Mr. Northrop has contributed the section on classification. In a similar way, under “ Phosphate lands,” A. R. Schultz and R. W. Richards, the former the chairman of the | phosphate section in the land-classification board and the latter a geologist who has worked out with great thoroughness and detail the complicated structural problems of the phosphate fields in south- eastern Idaho and adjacent parts of Wyoming, have collaborated in the general discussion of phosphate problems, Mr. Schultz being re- sponsible for the section on classification. The description of potash- bearing lands and their classification is the joint contribution of A. R. Schultz and H. S. Gale, Mr. Gale being the geologist in charge of the section of nonmetalliferous deposits of the geologic branch. E. H. Finch, of the land-classification board, who has been closely identi- fied with the cooperative work between the Survey and the General Land Office, has contributed the section on “ Miscellaneous nonmetal- liferous lands,” and F. C. Calkins, one of the experienced economic geologists of the Survey, who has had much to do with the classifi- cation of the lands in the Northern Pacific grant, has written the discussion of metalliferous mineral lands and the problems involved in their classification. The section on “ By-products of mineral-land classification ” was written by G. S. Rogers, a geologist of the geo- logic branch, whose recent work has been done in the western coal fields. The discussion of classification in relation to water resources has been prepared under the direction of N. C. Grover, chief engineer of the land-classification board, M. O. Leighton, Herman Stabler, E. ©. La Rue, and W. B. Heroy collaborating. Messrs. Grover, Stabler, and Heroy have prepared the sections relating to classifica- tion and office procedure, while Mr. Leighton, as chief of the water- resources branch of the Survey, and Mr. La; Rue, one of the ex- perienced field engineers of that branch, have cooperated in prepar- ing the discussion of field methods. | DEVELOPMENT OF ORGANIZATION FOR LAND CLASSIFICATION. BI It is noteworthy that the authors of the sections of this publica- tion describing the procedure employed in the work have themselves originated for the most part the methods that are so essential to successful and authoritative land classification. Mention should also be made here, however, of the important part played by A. C. Veatch, the chairman of the land-classification board at the time of its organi- zation, by C. Willard Hayes and Waldemar Lindgren, former chief geologists of the Survey, and by M. R. Campbell, who has been in charge of the geologic work in the western coal fields continuously since 1906 and has supervised the preparation of the sections on geologic field methods in this bulletin. DEVELOPMEN™ OF THE SURVEY’S ORGANIZATION FOR LAND CLASSIFICATION. The report of the committee of the National Academy of Sciences on the surveys of the Territories, prepared in accordance with the terms of a clause in the sundry civil bill approved June 30, 1878 (20 Stat., 206, 230), contains these statements indicating the opinion of the committee as to the land-classification functions of the bureaus whose organization its members were recommending: The best interests of the public domain require, for the purposes of intelli- gent administration, a thorough knowledge of its geologic structure, natural resources, and products. The domain embraces a vast mineral wealth in its soils, metals, salines, stones, clays, etc. To meet the requirements of existing laws in the disposition of the agricultural, mineral, pastoral, timber, desert, and swamp lands, a thorough investigation and classification of the acreage of the public domain is imperatively demanded. * * * The Land Office shall also call upon the United States Geological Survey for all information as to the value and classification of lands. * * #* The publications of the Geological Survey should consist of an annual report of operations, geological and economic maps illustrating the resources and classi- fication of the lands, reports upon general and economic geology in all its branches, with the necessarily connected paleontology. Maj. J. W. Powell, reporting to the Secretary of the Interior on November 1, 1878, in response to the request of the acting president of the National Academy of Sciences to transmit any information available in the Department of the Interior as to surveys then in existence, after listing the classes of lands recognized under the laws, adds the following comment: An examination of the laws * * * will show that the classes of lands mentioned above are therein recognized, and in the administration of the laws relating to these lands those belonging to each specific class must be deter- mined; but no adequate provision is made for securing an accurate classifica- tion, and to a large extent the laws are inoperative or practically void; for ex- ample, coal lands should be sold at $10 or $20 per acre, but, the department: having no means of determining what lands belong to this class, titles to coal lands are usually obtained under the provisions of statutes that relate to lands 12 CLASSIFICATION OF THE PUBLIC LANDS. of other classes—that is, by purchasing at $1.25 per acre, or by homestead or preemption entry. An examination of the laws will exhibit this fact—that for the classification contemplated therein a thorough survey is necessary, embrac- ing the geological and physical characteristics of the entire public domain. After extended hearings before the House and Senate committees and the publication of many documents bearing upon the questions involved, Congress, in March, 1879, agreed upon a law which em- bodied the recommendations of the Academy of Sciences for the abolition of the Territorial surveys and the establishment of the United States Geological Survey but made no provision for the mensuration survey also recommended by the Academy. Under the law approved March 3, 1879 (20 Stat., 377, 394), estab- lishing the office of Director of the Geological Survey, it is pro- vided— That this officer shall have the direction of the geological survey and the classification of the public lands and examination of the geological structure, mineral resources, and products of the national domain. Clarence King, the first Director, who entered upon his duties May 24, 1879, discusses the functions of the then newly created organization in his first annual report to the Secretary of the Inte- rior dated November 1, 1880. In this discussion he states that— * Two special and distinct branches of duty are imposed upon the Director of the Geological Survey—(1) the classification of the public land and (2) the examination of the geological structure and mineral resources. As regards the classification of the public lands, the text of the law leaves an uncertainty whether this classification is intended to be a scientific exposi- tion of the kinds of lands embraced in the national domain, such as arable, irrigable, timber, desert, mineral, coal, iron, showing the practical values and adaptabilities of the various classes or kinds of soil and surface, or whether, on the other hand, it was intended to furnish a basis of classification upon which the Government should part title to portions of the public domain. * * #* Upon examination of the existing land system, I have assumed that Congress, in directing me to make a classification of the public lands, could not have in- tended to supersede the machinery of the Land Office and substitute a classifi- cation to be executed by another bureau of the Government without having distinctly provided for the necessary changes within the Land Office and ad- justment of relations between the two bureaus. * ; ee I have therefore concluded that the intention of Congress was to begin a rigid scientific classification of the lands of the national domain, not for pur- poses of aiding the machinery of the General Land Office by furnishing a basis of sale, but for the general information of the people of the country, and to produce a series of land maps which should show all those features upon which intelligent agriculturists, miners, engineers, and timbermen might here- after base their operations, and which would obviously be of the highest value for all students of the political economy and resources of the United States. Studies of this sort, entirely aside from the administration of the Land Office, can be made of the highest practical value; and to this end a careful beginning has been made. DEVELOPMENT OF ORGANIZATION FOR LAND CLASSIFICATION. 18 This interpretation by Director King of the duties imposed upon the new bureau by that clause in the organic act charging him with responsibility for the classification of the public lands prevailed in part until about 1906, when the pressing need of the Department of the Interior for an adequate classification of mineral lands for pur- poses of administration led to a revival of this suspended function of the Geological Survey, not, as Director King seemed to think necessary, by superseding the machinery of the General Land Office, but by cooperation, financial and administrative, between that bu- reau and the Survey and by a series of orders from the Secretary of the Interior, to whom both bureaus report. These orders so de- fine the part that each is to bear in public-land administration as to make the Survey chiefly responsible for the physical classifications. At first the work was concentrated largely on the classification and valuation of coal land, and this phase continues to be quantitatively the most important. In the Twenty-eighth Annual Report of the Survey, for the fiscal year ended June 30, 1907, in discussing the work on the coal lands Director Smith makes this statement: Special investigations were conducted last year to determine the extent of the coal lands remaining in the possession of the Government and the quality and value of the coal deposits on these public lands. This work will be contin- ued on a larger scale and under a more comprehensive plan. Special attention will be given to the classification and valuation of the coal lands and their prompt segregation from the noncoal lands. This work is to be provided for by a joint allotment from the appropriations for the geologic and topographic sur- veys and that for testing coals belonging to the Government, and the General Land Office is also cooperating. i The Twenty-ninth Annual Report of the Survey, for the fiscal year ended June 30, 1908, includes with some matter on the special fea- tures of the work of the Survey a discussion of land classification, which contains the following statement: In the last few years the Geological Survey has broadened the scope of its work in the classification of the mineral lands of the public domain. At the time of the organization of the Survey the classification intended by Congress was believed to be general in character and such as could be expressed on maps issued for the general information of the people. The present interpretation of the law is that the classification should be more definite, and therefore, during the last year, the Survey has continued its special field surveys of the coal lands belonging to the Government. * * #* Increased demands have also been made on the mining geologists of the Survey for assistance in determining the mineral or nonmineral character of land for which title from the Government is sought. This work, which has become an increasingly important feature of the Survey’s activities, was definitely recognized by the organization, in December, 1908, of a land-classification board as a section of the geologic branch, and by the reorganization of the board on May 1, 1912, into a branch coordinate in rank with the other Survey branches. | 74 CLASSIFICATION OF THE PUBLIC LANDS. The Geological Survey has been in existence as a distinct organi- zation for about 34 years. The organizations which it succeeded and whose functions it continued to perform and gradually to enlarge upon as new duties were given it by Congress collected engineering material that was epitomized in topographic maps and geologic ma- terial that appeared either as geologic maps, as reports on geologic problems, or as data on the mineral resources of the Territories. Early in the Survey’s history the necessities of its geologic work required the organization of a topographic branch for the prepara- tion of base maps. Although these maps were intended to serve primarily as bases on which to delineate and present geologic mate- rial, they have proved to be of great value for other and wider uses. Not the least. of these uses is that to which they are put in land classification. The thousands of maps issued are graphic engineer- ing reports on the physical and cultural features of the areas they represent. They are essential to the study of drainage areas, irriga- bility of lands, possible power development, and rights of way, and supplemental sheets now prepared give additional data on the dis- tribution of timber and of springs, of desert and of grass land, and of cultivated and irrigated areas. On March 20, 1888, Congress, by joint resolution, directed the Sec- retary of the Interior, through the United States Geological Survey, to make a special investigation of the practicability of constructing reservoirs for the storage of water in the arid regions of the United States. This work was supported for a time by appropriations but was later discontinued by Congress after many reservoir sites had been examined and segregated and a number of reports valuable in the classification of the lands of the arid regions had been published. After the irrigation survey was abolished the division of hy- drography was organized within the Geological Survey, at first as a part of the topographic branch and later with special small appro- priations, its purpose being to continue that part of the work of the irrigation survey that involved the study of the available water resources of the Western States and Territories. As the value of this work to reclamation became manifest, Congress responded by increasing the amount of the funds annually available for this pur- pose until in 1903 they reached the sum of $200,000 a year. On June 17, 1902, the reclamation act (32 Stat., 388) was passed. This act represented the culmination toward which the work of the division of hydrography had up to that time been tending. That work gave definite information as to available supplies of water and the lands on which the water could be used. The reclamation act authorized the construction of works for the application of these waters and the reclamation of the tributary lands. But the reclama- tion fund is not available for general studies of water supplies; it can DEVELOPMENT OF ORGANIZATION FOR LAND CLASSIFICATION. 15 be used only for studies of water available for use on specific projects. The work of the division of hydrography therefore did not cease with the organization of the Reclamation Service but has been continued in the Geological Survey by the water-resources branch. Developments within the geologic branch since its organization have likewise marked a steady evolution from its original type. The branch has grown, its appropriations and its force have increased, and its work has been more closely subdivided and specialized and has attained greater refinement in all departments; and while this evolution has been taking place it has steadily accumulated a great mass of facts bearing on the geology and mineral resources of the United. States. The material accumulated since their organization by the field branches of the Survey—the geologic branch, the topographic branch, the water-resources branch and its predecessors, the irrigation survey and the division of hydrography—constitutes a vast body of infor- mation concerning the public domain—its geology, its geography, and its water supplies and the engineering features that control the distribution of these supphes. This store of information is by no ineans complete, for many problems are still untouched and many areas are unexamined, but nevertheless the archives of the bureau contain a greater mass of material of the kind required for classify- ing the remaining lands of the public domain into types that accord with their various uses than exists anywhere else in the public records. With the accumulation of the data indicated the Department of the Interior and its bureaus have become increasingly ready and will- ing to call on the Survey for assistance in that phase of public-land administration which requires as its basis a classification of the lands into the types recognized in the statutes. The requests made by the department for information contained in the Survey’s records were at first sporadic; later they became more frequent and numerous, so that it became necessary to create within the Survey itself an organization to assemble this informa- tion systematically and transmit it to the department and to other bureaus in the department in such form as would be most readily applicable to the solution of administrative problems. This organi- zation was named the land-classification board and was first formed as a section of the geologic branch and finally made a branch of the Survey coordinate in functions and responsibility with the field branches whose evolution has been briefly outlined. The Survey’s organization for classifying the public lands con- sists, then, fundamentally and primarily, of three field branches— geologic, topographic, and water resources—and finally of the re- cently organized office branch known as the land-classification board, 16 CLASSIFICATION OF THE PUBLIC LANDS. with its staff of geologists and engineers, who analyze and translate into terms of public-land administration the data collected by the geologists and engineers of the field branches. In its organization the land-classification board is in a sense a replica in miniature of the bureau of which it is a part. It consists of two divisions—a division of mineral classification and a division of hydrographic classification. The first corresponds to the geologic branch and receives, digests, and issues as land-classification data the material collected by the field geologists; the second bears a cor- responding relation to the topographic and water-resources branches and similarly utilizes the engineering data gathered by the field force of those branches. Again, the division of mineral classification con- tains a number of sections which correspond closely with similar sec- tions in the geologic branch. These sections, in the organization as it exists at present, are the coal section, the oil section, the phosphate section, and the metalliferous section, corresponding roughly to similar sections in the geologic branch as well as to the principal of the natural resources with which the board deals. The work of the coal section, described elsewhere in detail, is to define the principles that shall control coal-land classification, to determine the character of the data necessary for this purpose, to receive these data as collected by the field geologists of the geologic branch, and to make and promulgate the classifications and valuations by the use of these data—this in accordance with principles already carefully defined. The coal section consists of a chairman, who is a member of the land-classification board and one of the most ex- perienced coal geologists of the Survey, and a number of additional members, who are familiar with coal problems and are chosen usually from the geologic branch, although some have been chosen from other sections of the board. The coal section thus organized holds frequent sessions, which are attended by coal geologists who have data to present for consideration. At these sessions the problems that have arisen in the field are discussed and solved in accordance with the established rules of the board. The form and the procedure for ihe submission of data, including data for classification and valua- tion, are prescribed, and after these data are received appropriate recommendations are made to the Director for withdrawals or restora- tions, and valuation plats are prepared for his approval and for promulgation by the Commissioner of the General Land Office. Each step of these various processes is carefully recorded, in order that all evidence considered and all action taken may readily be reviewed at any future time should questions arise as to the correct- ness of the action or should new evidence be presented. Thereafter when reports on any subdivision classified are called for by any DEVELOPMENT OF ORGANIZATION FOR LAND CLASSIFICATION. 17 Government department, by other bureaus, by public officials, or by citizens, prompt response can be made in the light of all action there- tofore taken affecting that subdivision. Because the laws applicable to coal lands, unlike those providing for the disposal of lands containing other minerals, authorize not merely the classification of the public domain as coal or noncoal land but the valuation and sale of the coal land at prices to be fixed in accordance with the quantity, quality, and accessibility of the coal, more complete action is possible in dealing with coal lands than with others, and the very completeness of action required involves corre- spondingly difficult problems, Similar sections have been organized within the division of mineral classification for dealing with lands that may contain oil and gas, phosphate, and other nonmetalliferous minerals and for such limited and special classifications of metalliferous land as are required by law. The organization of each of these sections is similar to that of the coal section, and the action taken by them follows similar lines. Members of. the land-classification board act as chairmen of the oil and gas section, the phosphate section, and the metalliferous section. Other members of the sections are selected from geologists who are engaged in field work on the particular resource which is the subject matter of the board’s action. A similar but less formal organization has been effected for the division of hydrographic classification. This division deals with those phases of land classification that depend on water supply and that involve the solution of engineering problems. ‘The division’s chief task is the classification of lands according to their irrigability and their power value, but it also reports on various complex prob- lems which are involved in the consideration of miscellaneous rights of way. This division is administered by the chief engineer of the board. As occasion may demand, sections are organized within it for disposing of the various problems that arise. At present (1913) there are two such sections, one dealing with water powers and the other with irrigation. Each section consists of a chairman and two or more additional members, usually chosen from the engineers or hydrographic geologists of the water-resources branch. The section thus constitutes a committee which, like the sections in the division of mineral classification, may give preliminary consideration to a problem of classification (under the enlarged-homestead act, for example), or it may prepare instructions for the guidance of the field engineer or geologist and later give consideration to the data that he has obtained and prepare appropriate recommendations. The field branch with which these sections necessarily maintain closest relations is the water-resources branch, although their relation with 78894°—Bull. 587—13——2 18 CLASSIFICATION OF THE PUBLIC LANDS. the topographic branch is but little less close. The graphic data on drainage areas, stream grades, reservoir sites, and general topo- graphic features which result from the work of the topographic branch, when combined with the data on water supply assembled by the water-resources branch, furnish the basis for determining most irrigation and power problems. In addition to the work done by these technical divisions and sec- tions, certain miscellaneous duties are performed by means of a less well-defined administrative division of the board, whose functions are closely interwoven with those of the technical divisions and are participated in by some of the same officers. A committee, of which the secretary of the board is chairman, has charge of the filing and docketing system. The chairman of the oil section is responsible for the records in the division of mineral classification and for the details of cooperation with the Land Office and the Indian Office; the chair- man of the water-power section is chiefly responsible for the records in the division of hydrographic classification. _ The more important elements in the organization are set forth in the following outline: LAND-CLASSIFICATION BOARD. Administration. Chief of board. Chief engineer. Secretary. Division of mineral classification. A geologist in charge. Coal section. Oil section. Phosphate section. Metalliferous section. Division of hydrographic classification. A chief engineer in charge. Water-power section. Irrigation section. HISTORY AND LEGAL BASIS FOR LAND CLASSIFICA- TION. INTRODUCTION. Ever since the policy of selling the lands of the public domain as a source of national revenue was abandoned and the contrary policy of so disposing of them as to promote settlement and development was adopted, the administration of the land laws passed by Congress HISTORY AND LEGAL BASIS. 19 has required a segregation of the lands into classes according with their character. It is apparent, although it has nowhere been ex- pressly stated by Congress, that the fundamental principle guiding that body has been to dispose of each tract of the public domain for the use to which it is best adapted. Thus the laws have provided that agricultural entry should not be made upon valuable mineral Jands, that lands containing deposits of coal should be sold only as eoal lands, and so on for all other classes of lands. The underlying theory of devoting the public lands to their highest use and the consequent necessity for classification of uses may easily be recognized from a study-of the brief outline of the more important existing land laws given on pages 20-32. The same recognition by Congress of the necessity for land classifi- cation is shown by numerous acts calling for the classification of specific areas. Nearly every law providing for the opening of an Indian reservation has required the lands to be classified preliminary to their disposition. The act of February 26, 1895 (28 Stat., 683), provides and appropriates for a definite classification of lands within the limits of the Northern Pacific Railroad grant in portions of Montana and Idaho, and the sundry civil bill of June 25, 1910 (36 Stat., 739), makes further appropriation for the same purpose. The act of October 2, 1888 (25 Stat., 526), makes provision for a classifica- tion that was not necessary to the administration of the land laws then in force by appropriating $100,000 to the Geological Survey “for the purpose of investigating the extent to which the arid region of the United States can be redeemed by irrigation and the segrega- tion of the irrigable lands in such arid region and for the selection of sites for reservoirs and other hydraulic works necessary for the storage and utilization of water for irrigation and the prevention of floods and overflows.” A relatively recent indication of Congressional belief in land classification is afforded by the two acts of June 25, 1910, providing for the withdrawal of lands from entry, the one of public lands, the other of lands in Indian reservations. As withdrawals constitute one step in the process of classifying the public domain, the passage of bills authorizing withdrawals clearly reaffirms the established policy of land classification. One of these acts (36 Stat., 847), in terms sanctions the classification of lands, providing— That the President may at any time, in his discretion, temporarily withdraw from settlement, location, sale, or entry any of the public lands of the United States, including the District of Alaska, and reserve the same for water-power sites, irrigation, classification of lands, or other public purposes to be specified in the orders of withdrawals, and such withdrawals or reservations shall remain in force until revoked by him or by an act of Congress. 20 CLASSIFICATION OF THE PUBLIC LANDS. The other (36 Stat., 855) provides— That the Secretary of the Interior be, and he is hereby, authorized, in his discretion, to reserve from location, entry, sale, allotment, or other appropria- tion any lands within any Indian reservation, valuable for power or reservoir sites, or which may be necessary for use in connection with any irrigation project heretofore or hereafter to be authorized by Congress. Thus the plain intention of Congress that the public lands shall be classified and that they shall be disposed of in accordance with their classification is shown by definite provisions for the classification of certain areas, by the authorization of land withdrawals, and by the creation of an organization—the Geological Survey—among whose prescribed duties the classification of the public lands is spe- cifically stated. But were there none of these evidences the fact that Congress has consistently recognized the necessity for the classifica- tion of public lands would be established beyond question by a study of the land laws, which, as the following brief outline will show, could not be administered without some sort of segregation into classes. This outline does not purport to set forth in detail all the laws under which disposition is made of the public lands; it only sketches the principal features of the more important laws. LAND LAWS. GENERAL DIVISIONS. The land laws of the United States may be divided into two dis- tinct classes—public-land laws and land grants. ‘The first are general laws providing for the disposition of lands to any duly qualified person who may wish to avail himself of the prescribed conditions; the second are special laws granting certain areas to specified indi- viduals, corporations, or State governments. The laws of each of these two classes may in turn be subdivided, the public-land laws falling loosely under the headings of agricultural, mineral, and coal land laws and laws relating to public and quasi-public uses, whereas land grants may be divided into grants made to States and grants made to railroads. PUBLIC-LAND LAWS. AGRICULTURAL-LAND LAWS. Purpose.—In general, the purpose of the laws relating to agri- cultural land is to promote the settlement of the public domain. The principal acts are those providing for homesteads, forest home- steads, enlarged homesteads, desert-land entries, entries under the reclamation act, the sale of isolated tracts, and timber and stone entries. Every tract of land to which these laws are applied must be nonmineral in character. | | HISTORY AND LEGAL BASIS. 21 Homesteads.—The homestead act was passed by Congress in 1862 and was approved by President Lincoln on May 20 of that year (Rev. Stat., 2289-2303). It marked the final abandonment of the policy of disposing of the national domain as a means of providing public revenue. Until 1912 the homesteader was required to estab- lish a residence on his land and to reside thereupon for a period of five years. No definite amount of cultivation was required, but the building of houses and barns and the cultivation of a part or all of the area were regarded as evidence of the good faith of the entryman in entering the land for the purpose of building a home for himself, this being the fundamental object of the homestead act. On June 6, 1912 (37 Stat., 123), the law was amended by reducing the five years’ residence theretofore required to a residence of three years. The requirement as to residence is modified by what is known as the “commutation clause” (Rev. Stat., 2301, as amended by the act of March 3, 1891, 26 Stat., 1098), which provides that after 14 months’ residence and cultivation title may be obtained by paying a fixed price per acre, this price being either $2.50 or $1.25, the first if the Jand is within, the second if it is without the limits of a railroad grant. Homesteads reserving coal or oil and gas to the Government under the acts of June 22, 1910 (36 Stat., 583), and August 24, 1912 (37 Stat., 496), described later (p. 45), may not be commuted. The amendment of June 6, 1912, also provides that the entryman must cultivate “not less than one-sixteenth of the area of his entry be- ginning with the second year of the entry and not less than one- eighth beginning with the third year of the entry and until final proof.” The homestead act contains the clause “nor shall any mineral lands be liable to entry and settlement.” ‘The area of the homestead is restricted to 160 acres. | Forest homesteads.—Lands in national forests are not in general open to agricultural entry, but under the*act of June 11, 1906 (34 Stat., 233), forest-reserve lands which are chiefly valuable for agri- culture, which are not needed for public purposes, and which, in the opinion of the Secretary of Agriculture, may be occupied with- out injury to the forest, may be entered under the homestead laws. Application for a particular tract desired, which must not exceed 160 acres in area nor 1 mile in length, must be made to the Secretary of Agriculture. The land is then examined by a field agent of the Forest Service, and if his report is favorable the land is listed to the Depart- ment of the Interior, where homestead entry is allowed. The entry thereafter proceeds as would any other entry under the homestead law, but no commutation is permitted. The law differs from all other agricultural-land laws in that the land must be chiefly valuable for agriculture and that the entry may be described by metes and bounds instead of by legal subdivisions of the public-land survey. a2 CLASSIFICATION OF THE PUBLIC LANDS. Enlarged homesteads——An act known as the enlarged-homestead act, approved February 19, 1909 (35 Stat., 639), provides that in the States of Colorado, Montana, Nevada, Oregon, Utah, Washington, Wyoming, Arizona, and New Mexico a homestead entry may com- prise 320 acres of nonmineral lands which have been designated by the Secretary of the Interior as not susceptible of successful irriga- tion at a reasonable cost from any known source of water supply. On June 17, 1910 (36 Stat., 531), a similar act was approved apply- ing to Idaho, and on June 13, 1912 (87 Stat., 182), one applying to. California and North Dakota. The requirements as to residence and cultivation on an “enlarged homestead ” are, under the act of June 6, 1912 (37 Stat., 123), the same as those for other homesteads, but enlarged-homestead entries may not be commuted by cash payment. The enlarged-homestead acts further provide that tracts in the States of Utah and Idaho which have not upon them “ such a sufficient supply of water suitable for domestic purposes as would make continuous residence upon the lands possible ” may be subject to entry without the necessity of residence, but one-eighth of the area of the entry must be cultivated from the beginning of the second year and not less than one-fourth from the beginning of the third year until final proof has been submitted. Desert land.—Under the desert-land acts entry may be made on lands which, by reason of lack of rainfall, will not produce native hay or other agricultural crops or trees without irrigation. Such lands may be entered by irrigating and producing crops on not less than one-eighth of the area. No residence is required. Any person duly qualified may enter an area not exceeding 320 acres of such lands. It should be noted, however, that this 320-acre area is limited by the fact that one person is not permitted to acquire more than 320 acres of land under the public-land laws, mineral entries not being taken into account. The entryman is given three years in which to reclaim his land, which must be nonmineral in character. Reclamation act.—Under the act of June 17, 1902 (32 Stat., 388), - the Government is building great irrigation projects for the reclama- tion of arid and semiarid lands in the West. Lands thus reclaimed, which must be nonmineral in character, may be entered by any person qualified to make a homestead entry. The enterable area is not more than 160 acres but is different in the different projects and in different parts of the same project. No charge is made for the land, but the entryman must pay his proportional part of the cost of the project in ten yearly installments. Three years’ residence on the land is re- quired, as under other homestead laws, and at least one-half the area of the entry must be cultivated before title can be obtained. Isolated tracts—Small tracts of public land surrounded by lands which have already been entered may be purchased as isolated tracts HISTORY AND LEGAL BASIS. 23 under section 2455 of the Revised Statutes as amended by the act of June 27, 1906 (34 Stat., 517). Under the act of March 28, 1912 (37 Stat., 77), mountainous tracts which are not isolated by entered land but which are unfit for cultivation may be purchased by the owner of adjoining land in the same manner as isolated tracts. A person desiring to purchase land in this manner files with the local land officers an application to purchase, whereupon, if the lands are nonmineral and are in fact isolated or mountainous, a public sale is advertised, at which the lands are sold to the highest bidder. No residence or cultivation is necessary, but the land must be nonmineral. Timber and stone lands—The foregoing five classes of laws con- stitute the principal types under which agricultural entry may be made. There remains a sixth class of considerable importance, which, while applying only to lands more valuable for other purposes than for agriculture, is nevertheless more nearly allied to the agricultural laws than to the laws relating to minerals, coal, or quasi-public uses. Under the act of June 3, 1878 (20 Stat., 89), and acts amendatory thereof nonmineral lands which are valuable chiefly for the timber and stone thereon and which are unfit for cultivation may be ap- praised and sold at not less than $2.50 per acre. Application to purchase is made in a manner similar to that required by the laws relating to isolated tracts, but there is no public sale. There is instead an appraisement of the value of the land by an appraiser designated by the Government, and the lands are purchased at the price so fixed. MINERAL-LAND LAWS. General provisions.—The mineral-land laws were in the main for- inulated in the 10 years between 1865 and 1875. They are based largely on local mining customs which had attained the force of law in the mining camps on the public domain. Their constant purpose has been to promote mineral development. The act of May 10, 1872 (Rev. Stat., 2319), provides that “all valuable mineral deposits in lands belonging to the United States, both surveyed and unsurveyed, are hereby declared to be free and open to exploration and purchase, * * * by citizens of the United States and those who have declared their intention to become such.” No important amendment of the mining laws has been made since the date of this act. At that time the known deposits of importance on the public domain comprised only metalliferous minerals, and the laws were framed with such deposits in mind, provision being made for two classes of claims— _ lode and placer. From time to time since the adoption of the mining laws one and another nonmetalliferous mineral has become important, and its entry under the placer law has been authorized by Congress, which has thus specially provided for the entry of lands that are chiefly valuable for petroleum, salines, and building stone. 24 CLASSIFICATION OF THE PUBLIC LANDS. The general procedure under the mineral-land laws is the same for all classes of deposits. The person who desires to obtain mineral lands must first make a discovery of valuable mineral within the limits of the claim that he wishes to locate. This discovery, as in- terpreted by the Department of the Interior and the courts, must be such a showing of mineral as would warrant a man of ordinary pru- dence in expending his time and labor upon the claim in the reason- able hope and expectation of developing a paying mine thereon, or, as expressed in one of the latest decisions (40 L. D., 271) in: terpreting the lode law, “ there must be actually physically exposed ” within the limits of the claim “a vein or lode of mineral-bearing rock in place, possessing in and of itself a present or prospective value for mining purposes.” The method of location, the posting of location notices, and other similar matters are determined by the local customs or miners’ rules of the district in which the claim is situated. In order to hold a claim against possible adverse claim- ants—in other words, to prevent its being jumped—at least $100 worth of work, called “ assessment work,” must be performed on it each year. After $500 worth of assessment work has been done and certain requirements as to recording and surveys have been met, the applicant, on payment of a fixed price per acre, is entitled to patent. Lodes.—Claims for veins of quartz or other rock in place are known as lode claims (Rev. Stat., 2320). Their size is governed by the rules of the mining district in which they are situated but must not exceed 600 feet in width and 1,500 feet in length. Claims need not conform to the public-land system of surveys and may be in al- most any shape, provided only that the end lines of each claim shall be parallel to one another. When patent is sought, a purchase price of $5 an acre must be paid. All veins that come to the surface within a given claim are the property of the owner of that claim through their entire depth (Rev. Stat., 2322) but only for such portion of their extent as lies between the end lines of the claim. Thus the owner of the outcrop or apex of a lode may follow it downward indefinitely so long as he stays within his end lines and may mine it without regard to the ownership of the land under which it passes. This provision, which is known as the “law of the apex,” has unquestionably been more provocative of litigation than any other provision of American land law. The lode law provides also for the discovery in driving tunnels of veins not outcropping on the surface and not previously known to exist. It grants to the discoverers the right to 1,500 feet of extent of each vein so discovered within 3,000 feet of the face of the tunnel, with the same apex right as if the discovery were made at the surface. Failure for six months to prosecute work on a tunnel acts HISTORY AND LEGAL BASIS. 95 as an abandonment of the right to veins which may subsequently be encountered. The number of claims which may be entered by one person under the lode law is unlimited, provided he does the necessary assessment work and otherwise complies with the law for each claim. More- over, the owner of a group of claims may concentrate his assessment work on one claim of the group if such work tends to the develop- ment of every claim in the group. Placers——The placer law, which was approved July 9, 1870 (16 Stat., 217), was intended to apply to gold and silver distributed through deposits of sand and gravel. As at that date there were no known important mineral deposits except veins and placers, the law provides (Rev. Stat., 2329) that “placer” claims shall include “all _ forms of deposit, excepting veins of quartz or other rock in place.” These placer claims are subject to entry and patent in a manner similar to lode claims, but where the lands have been surveyed the claim must conform to the legal subdivisions of the survey. The purchase price is $2.50 an acre. The maximum area that may be included in one claim by an individual is 20 acres, although, as in lode claims, there is no limit to the number of claims that may be entered. An association may enter in one claim an area equal to 20 acres for each member but not more than 160 acres. Only one dis- covery of mineral is required to support a placer location, whether it be of 20 acres by an individual or of 160 acres by an association. The applicant for a placer claim must make affidavit that there is not within the limits of the claim any valuable vein or lode and also that title is not sought in order to control watercourses or to obtain valuable timber. ‘The assessment work on each claim, whether of 20 or 160 acres, must amount to $100 a year and to $500 before patent may be issued. On placer as on lode claims annual assessment work to the amount of $100 for each claim in a group may be done on any one of the claims in the group, provided it tends to the exploration or development of all. Building stone-—By the act of August 4, 1892 (27 Stat., 348), the placer law was extended to apply to lands chiefly valuable for build- ing stone. The requirements as to discovery, assessment work, area, and price are the same as for other placers. It is to be noted that in this act the factor of relative value was for the first time specifically introduced into mineral-land law. The earlier laws provide for mineral entry on lands which are valuable for their mineral deposits. It has been argued that only lands whose mineral value is greater than their agricultural value are properly enterable as mineral land, and the decisions of the department and the courts can not be said to have settled the matter conclusively. In the building-stone and 26 CLASSIFICATION OF THE PUBLIC LANDS. subsequent extensions of the placer law, however, it is specifically stated that the lands must be chiefly valuable for the mineral upon whose discovery the claim is based. This extension of the placer law to cover building stone neither repealed nor conflicts with the timber and stone act of June 3, 1878 (20 Stat., 89), already discussed. Thus lands chiefly valuable for building stone may be purchased at an appraised value not less than $2.50 per acre or may be entered under the placer law and patented after the completion of the required amount of assessment work, on payment of $2.50 per acre. Ow.—About a quarter of a century after the passage of the placer law valuable deposits of petroleum were discovered on public lands. The discoverers, finding themselves without an appropriate law un- der which.to apply for a patent, made application under the placer law—not because it was fitted to the needs of the situation but be- cause of its general provision that all forms of deposit excepting veins of quartz or other rock in. place should be entered thereunder. The Department of the Interior, recognizing the undesirability of applying the placer law to oil and gas, refused to allow the applica- tions. On an appeal to Congress for relief, the act of February 11, 1897 (29 Stat., 526), was passed, providing that lands chiefly valuable for petroleum and other mineral oils should be enterable under the placer law. On February 12, 1903 (32 Stat., 825), specific authority was granted for doing assessment work on any one of a group of oil claims lying contiguous and owned by the same person or corpora- tion, not exceeding five claims in all, provided that such assessment work tends to develop or determine the oil-bearing character of all the claims. The requirement of discovery of valuable minerals as a prerequisite to location—a requirement reasonable enough when ap- plied to veins outcropping at the surface or to gold placers—is applied as rigidly to deposits of oil and gas, which, as a rule, can be discovered only after long and expensive exploration, as to other minerals. Lands included in petroleum placers, hike those entered for building stone, must be chiefly valuable for the purpose for which they are claimed. Salines—The act of January 31, 1901 (31 Stat., 745), extends the placer law to cover lands that contain salt springs or deposits of salt in any form and that are chiefly valuable therefor. This has been interpreted as including only sodium chloride, no specific pro- vision having been made for other soluble salts. The requirements as to area, assessment work, and price are those contained in the original placer law, except that the same person may not locate or enter more than one claim. The consideration of relative worth is again intro- duced. HISTORY AND LEGAL BASIS. O44 COAL-LAND LAWS. The law under which disposition is made of coal differs so radi- eally from the laws regarding other minerals that it is not ordinarily classed with the mineral-land laws. It was approved March 3, 1873 (17 Stat., 607), and was incorporated into the Revised Statutes as sections 2347 to 2352. Any qualified person may purchase an area of coal land not exceeding 160 acres on payment of not less than $10 an acre if the land is more than 15 miles from a railroad ‘and not less than $20 an acre if the land is within 15 miles of a railroad. An association of persons severally qualified may purchase 320 acres. An association of four or more persons who have opened and im- proved a coal mine upon the public lands and have expended not less than $5,000 in working and improving it may enter an area not ex- ceeding 640.acres. No person may make more than one coal entry, either individually or as a member of an association, and no asso- ciation any member of which has previously exhausted his coal right may purchase coal land. A person or association opening a mine on the public lands is entitled to a preference right of entry for the lands on which the mine is situated, provided that a “coal declara- tory statement” is filed within 60 days from the initial date of actual possession and the commencement of improvements upon the land. This preference right is good for one year only. The opera- tion of the law is restricted to surveyed lands, which must not be valuable for their content of gold, silver, or copper. For over 30 years after the passage of this law all coal lands were sold at the minimum prices of $10 and $20 an acre prescribed by the statute. Since 1907 the selling prices have been fixed by the Geo- logical Survey and have ranged from the minimum prices up to $600 an acre. LAWS RELATING TO PUBLIC AND QUASI-PUBLIC USES. The laws governing public and quasi-public uses of land differ from the other laws under discussion in that they provide for the use of rights of way for various specified purposes and do not con- template the transfer to the beneficiaries thereunder of fee title to the land affected. Railroads —By the act of March 3, 1875 (18 Stat., 482), Congress granted to railroad companies right of way to the extent of 100 feet en each side of the center line of a proposed railroad through the public lands, under prescribed conditions. Upon the approval by the Secretary of the Interior of the location map filed by any rail- road company, the road as located is noted on the plats in the Gen- eral and local land offices, and thereafter all public land over which such right of way passes is disposed of subject to such right of way. By act of March 2, 1899 (30 Stat., 990), Congress provided for similar —— 28 CLASSIFICATION OF THE PUBLIC LANDS. rights of way across Indian reservations, and by the act of March 3, 1899 (30 Stat., 1233), the Secretary of the Interior was authorized to approve rights of way for wagon road, railroad, or other highway across any forest reservation or reservoir site when in his judgment the public interest would not be injuriously affected thereby. Irrigation.—By act of March 3, 1891 (26 Stat., 1095), Congress granted to canal and ditch companies formed for the purpose of irrigation the right of way for canals, ditches, and reservoirs tothe extent of the ground occupied and 50 feet on each side of the mar- ginal limits thereof, across public lands and reservations, provided that no such right of way shall be so located as to interfere with the proper occupation by the Government, of any such reservation and that all maps of location shall be subject to the approval of the department of the Government having jurisdiction over such reserva- tion. Upon the approval by the Secretary of the Interior of the location map the right of way is noted on the plats in the General and local land offices and thereafter all public land over which the right of way passes is disposed of subject to such right of way. By act. of May 11, 1898 (30 Stat., 404), the use which may be made of the canals, ditches, and reservoirs for which right of way is secured under the act of 1891 was extended to include purposes of a public nature, water transportation, domestic purposes, and the develop- ment of power, as subsidiary to the main purpose of irrigation. The act of February 15, 1901 (31 Stat., 790), which provides for the issuance of revocable permits for the development of power, covers also canals, ditches, pipes and pipe lines, flumes, tunnels, or other water conduits and water plants, dams, and reservoirs used to pro- mote irrigation. Power.—Power development on the public lands and reservations can at this time (February, 1913) be accomplished only under the act of February 15, 1901 (31 Stat., 790), except that power develop- ment subsidiary to the main purpose of irrigation may be made under the irrigation acts and that power development on national for- ests for mining, milling, and municipal purposes may be made under the act of February 1, 1905 (33 Stat., 628). The act of February 15, 1901, authorizes the Secretary of the Interior to issue revocable per- mits, under general regulations to be fixed by him, for rights of way for electrical plants, poles, and lines for the generation and distri- bution of electrical power to the extent of the ground occupied by the works and not to exceed 50 feet on each side of the marginal limits thereof. The law provides that permits issued under this act shall not be held to confer any right, easement, or interest in, to, or over any public land, reservation, or park. The act of March 4, 1911 (36 Stat., 1253), authorizes the head of the department having jurisdiction over the lands to grant rights of way for a period not HISTORY AND LEGAL BASIS. 29 exceedmg 50 years upon the public lands, national forests, and reser- vations for poles and lines for the transmission and distribution of electrical power, to the extent of 20 feet on each side of the center line. Mining and milling—tThe act of February 1, 1905 (33 Stat., 628), grants rights of way within or across national forests for dams, reservoirs, water plants, ditches, flumes, pipes, tunnels, and canals for mining purposes and for the purposes of the milling and reduc- tion of ores. Outside of the national forests the use of similar rights of way for these purposes may be made only under revocable permit under the act, of February 15, 1901. Municipal uses—Rights of way for municipal use for procuring water supply or for developing power may be obtained within a national forest under the act of February 1, 1905, and outside of the forests under the act of February 15, 1901. LAND GRANTS. GRANTS TO STATES. In aid of schools and State institutions ——The Continental Con- gress, about the year 1785, declared that to each State created out of the public domain there should be given a certain portion of each township in the State, the proceeds derived therefrom to be used for public education. Accordingly, when the first State, Ohio, was ad- mitted into the Union from the public domain, April 30, 1802 (2 Stat., 173), sec. 16 of each township was granted for the estab- lishment of a school fund. As other States have been admitted this practice has been deviated from only in adding to the acreage eranted. Sec. 16 has been a school section in every public-land State; to this sec. 86 has been added in many States, and in some States secs. 2, 32, and 36. The title of the State to these sections attaches immediately upon survey, unless the lands are at that date known to be mineral in character or are included in a valid settle- ment or other claim under the public-land laws or are within a forest, military, Indian, or other reservation. In any of these contingen- cies the State does not obtain title, but may select an equal area of nonmineral lands elsewhere. These are known as indemnity lands. As a rule they are not at once selected by the States but are selected only as the demand for specific lands arises. In addition to granting school lands in place and their associated indemnity lands, Congress has made to certain States “ quantity grants ”—that is, grants of specified quantities of nonmineral lands wherever the State may choose to select them—in aid of State insti- tutions, such, for example, as insane asylums. Selection rights under these grants, like those under the indemnity lists, are as a rule exer- 30. CLASSIFICATION OF THE PUBLIC LANDS. cised by a State only when individuals or corporations purchase the right to select certain desired lands. In aid of internal improvements.—In the early days of the coun- try’s history the right of Congress to grant public lands in aid of internal improvements was bitterly contested. The first legislation of this character was contained in the enabling act of the State of - Ohio, already cited, and provided that one-twentieth of the .pro- ceeds of the sale of public lands within the State should be given to the State to be used in establishing public roads. The first grant of specific lands in aid of internal improvements was not made until February 28, 1823 (3 Stat., 727). This grant also was made to the State of Ohio to aid in the-construction of a wagon road. Since that time there have been ten other wagon-road grants, eight canal grants, three river-improvement grants, and twenty railroad grants. The railroad grants to States alone approximate 40,000,000 acres. No grant to a State in aid of internal improvements has been made since the grant to Oregon for the Coos Bay wagon road on March 3, 1869 (15 Stat., 340). Although these grants were in terms made to the States, most or all of them were in fact made through the States to corporations that carried out the improvements contem- plated. Carey Act.—The act of August 18, 1894 (28 Stat., 372, 422), com- monly known as the Carey Act, and amendments thereto, the pur- pose of which is to aid the public-land States in the reclamaticn of the desert lands therein and in the settlement, cultivation, and sale of such lands in small tracts to actual settlers, authorize— (a) The temporary withdrawal of public lands from settlement or entry pending investigation and survey preliminary to the filing of an application for segregation, such withdrawn lands to be restored to settlement and entry at the end of one year from the date of with- drawal in case application for segregation is not theretofore made. (6) The segregation of public lands by the Secretary of the Inte- rior, contracts between the United States and any beneficiary State, and the reclamation of such lands by beneficiary States within 10 years from the approval of the State’s application (subject to an extension of 5 years). (c) The patenting to any beneficiary State of any tract of re- claimed land when satisfactory proof is made that an ample supply of water to reclaim it is actually furnished. Other important provisions of the Carey Act are in brief as follows: | Prior to segregation of lands or execution of contract between the United States and any State, such State shall file a proper applica- tion and present satisfactory plans for the reclamation of the lands. Lands that are not desert, lands that are occupied by bona fide set- HISTORY AND LEGAL BASIS. 31 tlers or under the mining laws, unsurveyed lands occupied with a view to entry under the desert-land laws, and lands containing val- uable deposits of minerals other than coal are not subject to segrega- tion. Coal lands (in Utah oil and gas lands also) may be segre- gated, but when patent is issued it must contain a reservation of these minerals to the United States. : The usual procedure under the Carey Act is about as follows: A corporation or individual applies to the State fcr the with- drawal of certain public lands proposed for irrigation. The State thereupon submits to the Interior Department an application for their withdrawal. On the approval of this application the State is allowed one year in which to investigate the project and prepare satisfactory plans for reclamation. The proposing company con- ducts the investigations and if a project that is considered feasible is developed makes application to the State for the segregation of the irrigable lands and offers to contract with the State for their reclamation. The State thereupon applies to the Interior Depart- ment for the segregation of the lands under the terms of the Carey Act and its amendments. If the plan of irrigation is found to be feasible, the irrigation company responsible, and the available water supply adequate, the lands are segregated and the contract for their reclamation is entered into between the United States and the State. When the irrigation works are completed to the satisfaction of the Government, patent is issued to the State or to its assigns. The State receives payment for the lands from the settler, and the irriga- tion company, either directly or through the State, receives payment from each settler for his proportionate share of the irrigation works and water rights involved. RAILROAD GRANTS. As already indicated, most grants of public lands in aid of internal improvements have been made through the States. Eight grants, however, have been made by Congress directly to corporations, to en- courage the building of railroads. Four of these grants, aggregating approximately 109,000,000 acres, were made to Federal corporations created by Congress for the purpose of building the roads subsidized, and four were made to State corporations. Of the four grants to State corporations, two were declared forfeited by Congress in 1874, the two remaining aggregating approxfmately 6,000,000 acres. The first of the grants made directly to corporations was the Pacific railroads bill of July 1, 1862 (12 Stat., 489), which provided for the building of the Union Pacific-Central Pacific line from Missouri River to the Pa- cific coast. This act granted to the railroad every alternate section for 20 miles on either side of the right of way. The Northern Pa- cific grant of July 2, 1864 (13 Stat., 365), conveyed every alternate 32 CLASSIFICATION OF THE PUBLIC LANDS. section for 40 miles on either side of the right of way. Neither of these grants contained restrictions as to the use to be made of the lands, but certain of the later grants required the lands to be sold only to actual settlers at prices not to exceed $2.50 an acre. The last of the railroad grants was made to the Texas Pacific Railroad Co. on March 3, 1871 (16 Stat., 573). Since that time Congress has consistently refused to grant lands, either to States or to corporations, in ald of internal improvements. . ; All the railroad grants were restricted to lands containing no minerals except coal and iron. These two were given to the rail- roads because of their use in the construction and operation of the roads. In certain cases the railroads were permitted to select other lands in lieu of those which, normally constituting a part of the grant, proved to be valuable for minerals other than coal and iron or to be included within Indian or military res- ervations or national forests or to have been covered by valid settle- ment. The right to make these lieu selections is usually sold by the railroads in the form of “scrip,” which may be filed on any vacant unreserved nonmineral land. ‘ys possi win oe eee NECESSITY FOR LAND CLASSIFICATION. 2f TABI, cate o|26|20 2030 |40} |sal60|75 20 bases, _| 0 iL |_| 20 2 20|20|30 ae ee 75 ee We 120) 2 2a|e0|20|20|a0|40)s0|c0|zeleo\eelaod | lal | hor || 1 ||| us aed Survey 7 2265 aa o2 SN Sa eaideobosted CEPT alz6|solvo|soled|volecl [PTT Tt] LL te _ beeotealeobelotsol Te o FiegurE 1,—Township map showing classification and valuation of coal lands. Large figures give price in Oo/lars per acre Coal land within $-mile Limit only for the classification of the land as mineral or nonmineral, a classification which may affect the interests of a large number of people, but also, in the case of coal land, for valuations aggregating millions of dollars. As an example, a copy of a township classifica- tion and valuation plat as transmitted to the General Land Office is given in figure 1. In June, 1912, private individuals purchased from the Government sec. 12 of this township, for which they paid the classified price as shown, amounting to over a quarter of a million dollars. In general the data are compiled by the field geologist from his original maps and notes in two forms. The first consists of a small- scale map with an accompanying general report presenting the re- sults of a study of the whole field. In this report the geologist dis- cusses the stratigraphy and structure of the field as well as the oc- 64 CLASSIFICATION OF THE PUBLIC LANDS. currence of economically important minerals. On the map accom- panying this report most of the finer details are omitted and only geologic formations and the outcrops of coal, phosphate, or oil sands are shown. The general report on a field contains a description of all that is known of the physical and chemical properties of the minerals occurring in that field. This report then serves as a basis for a set of general minutes, in which the appropriate section of the board outlines the application of the regulations governing the classifica- tion of lands containing those minerals to that particular field. After the general report has been considered by the proper section and the general minutes have been written, the field geologist pre- pares the classification data and in the case of coal land makes the valuation, under the immediate supervision and with the assistance of some member of the coal section of the board. Later the record is reviewed and passed on in detail by the entire section. Each 40- acre tract, and sometimes even each 24-acre tract, is considered indi- vidually and all facts affecting its classification as mineral or non- mineral are weighed. A report of the proceedings of the section for each township is prepared, giving in detail the result of the classifi- cation and the reasons therefor. This report becomes part of the permanent records of the land-classification board. Detailed reports on each township examined, with accompanying large-scale maps, constitute the second form of data. These are pre- pared in addition to the general report for all areas on which the smaller-scale map will not suffice for classification. On these large- scale township maps every feature that is possible of cartographic portrayal is represented—the outcrops, dips, and measured thick- nesses of all coal or phosphate beds or oil sands, all mines, prospects, or lodes, the location of these features with respect to established land lines, and, if essential, the topography of the surface. Each map is supplemented by a description which gives the dates and methods of field work, the condition of land surveys, the proximity to railroads, and a discussion of the geology. In the valuation of coal land all calculations by which the price per acre for each tract has been derived are given in detail. These reports and maps. are all permanently mounted, arranged in order of State, range, and township in loose-leaf locking binders, and filed in fireproof steel cases. As new information is acquired, from whatever source, with regard to the mineral character of any township, it is added in its proper place in the binder. Such in- formation consists of reports from field agents of the General Land Office, data obtained by members of the Geological Survey on subse- quent examinations, affidavits of public-land claimants, and other matter. The original field sheets and notebooks are likewise de- CLASSIFICATION OF MINERAL LANDS. 65 posited in the files of the land-classification board and are always readily available for use. Card indexes are maintained covering both sets of files. COAL LANDS. PURPOSE OF CLASSIFICATION. By act of March 3, 1873, Congress provided for the sale of coal lands belonging to the United States, specifying the conditions of sale and the minimum prices. To carry out the act it is necessary to determine, first}; what lands are coal lands (classification), and second, at what price they shall be sold (valuation). To give uni- formity to Executive action in this work certain rules have been prepared by the Geological Survey and approved by the Secretary of the Interior under the title “ Regulations for the classification and valuation of coal lands.” These regulations provide exclusively for the classification and valuation of coal lands and are not, to be confused with the regulations providing for the disposition of coal lands issued by the Land Office under the title “ Coal-land laws and regulations thereunder.” It is the province of the Geological Sur- vey to determine what lands are underlain by coal within the limits set by the classification regulations, and to it has also been assigned the work of valuing the lands classified as coal land. Classification and valuation must follow three antecedent steps—(1) the adoption of regulations formulating the principles and practice which are to govern classification and valuation; (2) the field examination to determine the presence, position, quality, and other features of the coal in the land; (8) the assembling of the field data in such form as to facilitate the work of classification and valuation by making possible the simultaneous consideration of all the facts. Finally, classification and valuation involve a consideration of all the known facts to determine what legal subdivisions of land are coal lands under the regulations and at what price they shall be sold. Preliminary to the detailed consideration either in the field or office of any area believed to contain valuable coals the lands are withdrawn from entry under the authority of the act of June 25, 1910 (36 Stat., 847), as amended by the act of August 24, 1912 (37 Stat., 497). A typical coal-land withdrawal order is appended with the accompanying letter of transmittal: DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY, Washington, January 21, 1913. The honorable the SECRETARY OF THE INTERIOR. Sir: Information on file in the Survey indicates that the land listed below contains valuable deposits of coal, and I therefore recommend the submission to 78894°—Bull. 587—183——5 66 CLASSIFICATION OF THE PUBLIC LANDS. the President for appropriate action of the following order of withdrawal, involving 1,600 acres. Very respectfully, Gro. OTIS SMITH, Director. JANUARY 28, 1918. Respectfully referred to the President with favorable recommendation. SAMUEL ADAMS, Acting Secretary. ORDER OF WITHDRAWAL. Coal-land erithdieae el Meats No. 10. Under and pursuant to the provisions of the act of Congress approved June 25, 1910 (86 Stat., 847), entitled “An act to authorize the President of the United States to make withdrawals of public lands in certain cases,” as amended by act of Congress approved August 24, 1912 (Public No. 316), and subject to the provisions of the act of Congress approved June 22, 1910, entitled ‘“‘An act to provide for agricultural entries on coal lands,” as amended by the act of Congress approved April 30, 1912 (Public No. 141), it is hereby ordered that the following-described lands be, and the same are hereby, withdrawn from settlement, location, sale, or entry and reserved for classification with respect to coal values: é Montana meridian. T.3N., R. 3 E., sec. 25, NE. 4, S34; sec. 26, SE. 4; sec. 35, EH. 3; sec. 36, all. Wo. H. Tart, President. JANUARY 29, 1913. METHODS OF CLASSIFICATION. PRINCIPLES INVOLVED. In preparing the regulations for classification three principles are paramount: (1) The regulations must be based on demonstrated facts or on well-founded and generally accepted inferences; (2) they must be based on all the stable, permanent factors involved; (3) they must be as definite yet withal as simple as possible. Ideally the regulations should be so simple that anyone at all acquainted with the subject could correctly apply them, and they should be so definite as to admit of little or no disagreement in interpretation. Neither of these ideal requirements can be realized. The workability of coal at a given point to-day depends on factors of two types. Those of the first type—such as quality, thickness, and depth—are intrinsic; those of the second type—such as rail- road transportation and markets—are extrinsic. To-day the extrin- sic factors may determine absolutely the commercial workability of a bed of coal at any locality. A coal bed 75 miles from a railroad and 50 miles from the nearest town, no matter how valuable it may be some day, has to-day a value that is purely prospective, depend- ing on an unknown factor—the time when transportation shall CLASSIFICATION OF MINERAL LANDS. 67 reach it. A new railroad may “make” a coal-mining district by opening new markets or may “ break” it by bringing in competition that it can not meet. To be stable, therefore, the regulations must be based directly on the intrinsic factors involved. Tracts classified as noncoal land are disposed of as such without further question as to their content of coal. Classification should therefore anticipate and assume the ultimate coming of conditions favorable for mining and marketing any coal if the coal is otherwise workable. If an 18-inch coal of a certain grade occurring under certain con- ditions is workable in Missouri to-day, hundreds of thousands of tons being: mined yearly, it would appear to be a reasonable assump- tion that a coal of like thickness and quality occurring under similar conditions elsewhere will be workable some day and should there- fore be classed as a workable coal; especially does this assump- tion appear reasonable when it is considered that everywhere the tendency is to extend the limits of workability. Coal mining has nearly always been conducted on a very close margin. In any new field—and most of the coal fields of the West to-day are new—only the most accessible, thickest, and best of the coal beds can be worked at a profit. Twenty years hence the most accessible coal will have been largely mined out and mining will be done on coal that is a little less accessible and that costs a little more to mine and that necessarily will sell at a little higher price. This higher price will permit the mining of other coal—a little thinner and a little poorer—which could not be mined profitably to-day, and the process will continue until all coal within minable limits is ex- hausted. The regulations attempt to define what these minable limits are, not in view of the conditions that may exist as the coal supply approaches absolute exhaustion, but in view of actual practice to- day under favorable conditions of transportation and of market. FACTORS INVOLVED. ESSENTIALS OF WORKABILITY. The workability of any coal will ultimately be determined by two offsetting factors—(1) its character and heat-giving quality, whence comes its value, and (2) its accessibility, quantity, thickness, depth, and other conditions that affect the cost of its extraction. It must be considered a workable coal if its value, as determined by its char- acter and heat-giving quality, exceeds the cost of extraction, either as judged by actual experience at the point where it is found or as judged by actual experience on similar coals similarly situated else- where. There are no absolute limits to any of the factors. The min- ing of 1 inch of coal that may involve the mining of 3 feet of rock is physically possible but would not pay. Most unworkable coal beds 68 CLASSIFICATION OF THE PUBLIC LANDS. lack one or more of three things—quality, thickness, accessibility— that is, they are too poor, too thin, or too deep. Other things—such as poor roof, gas, water, faults, pitch, and lack of timber—may render mining difficult and temporarily unprofitable, but most or all of them are subject to engineering control. They may depreciate the value of the coal and defer its mining but may not make it unworkable. | QUALITY, Coal is essentially a fuel. The heat afforded by burning coal is derived mainly from its carbon and the hydrogen that is free to burn. Associated with these are oxygen, nitrogen, water, and ash. A pound of the best coal, which contains about 90 per cent of carbon and “available” hydrogen and 10 per cent of the other ingredients, wili yield from 14,000 to 15,500 British thermal units. A British thermal unit (“B. t. u.”) is the amount of heat required to raise the temperature of 1 pound of water 1° F. under certain standard condi- tions. Poorer coals contain larger percentages of noncombustible constituents and correspondingly less carbon and available hydrogen, and their heating value (in British thermal units or other units of measurement) is reduced in much the same ratio. On analysis some coals show a content of all impurities that is in excess of the average; others show an excess of ash or water only; but whether the increase is in ash or water, or both, its effect is to decrease the heating value of the coal as expressed in B. t. u. Instead, therefore, of specifying the maximum quantity of ash or water allowable in a commercial or salable coal the regulations fix a minimum value in B. t. u. which will cover either one or any combination of these two or any other impuri- ties. The limit of allowable impurity in a salable coal is affected by the facts that very wet coals may be improved by air drying and that coals which are very high in ash may usually be improved by washing or may, perhaps, be used in a producer-gas plant. The possibility that improvements may be devised in the utilization of coal—such as its entire utilization at the mine for producing electric power—makes the determination of the powest limit of usable quality of coal diffi- “cult and very uncertain. Again, in a study of the B. t. u. value of low-grade coals that are now worked, difficulty is encountered in the fact that many of the earlier samples taken were weathered coal. On account of the possible improvement of the quality of the coal by drying or by washing, the lowest limit of usable quality is fixed by analysis of an air-dried sample, and if the coal as obtained in the mine contains a very high percentage of ash the possibility of its being washed is considered. Analyses of samples of coal cut in the mine from unweathered coal, according to the practice of the Geo- logical Survey and the Bureau of Mines, indicate that any coal mined CLASSIFICATION OF MINERAL LANDS. 69 commercially in the United States to-day will yield, after being washed or air dried, at least 8,000 B. t. u. This figure has therefore been fixed as the minimum B. t. u. value of any coal that shall be con- sidered workable. In practice the washed product of any coal sub- ject to washing must have at least 50 per cent of the weight of the unwashed coal. The washability of any coal is determined on a sample of one-quarter inch size by a float and sink test, the liquid used having a specific gravity of 1.5. Even if its workability is thus indicated in the laboratory it can not be considered workable unless there is sufficient water in the field for washing it. THICKNESS. More coal is unworkable because it is too thin than for any other reason. The result of a study of the relative cost of mining in relation to the thickness of beds is given on pages 83-86. For the purpose of classification a careful study was made of the thicknesses of coals that are actually mined in a large commercial way. Many of the facts disclosed by this study have been published. By platting these with reference to the B. t. u. content of the coal it became evident that in actual practice coals yielding 10,000 B. t. u. are worked with profit down to a thickness of 18 or 19 inches, that coals yielding 12,000 B. t. u. are worked down to 14 or 15 inches, and that better coals are mined from beds still thinner. Some coals of the quali- ties mentioned are mined from beds that are thinner than those noted above, but under very exceptional conditions. In considering the low- grade coals three special factors must be noted: (1) Most of them occur in rocks of more recent age than the others, which have been less affected by mountain-making forces and are therefore less indu- rated. On this account it is thought that future extensive mining may show the frequent necessity of leaving some of the coal for roof and of leaving larger pillars. (2) Owing to the air-drying loss in very wet coals they are likely to shrink considerably before they are marketed. (38) If the low B. t. u. value of these coals is due to their high content of ash an allowance should be made for loss in washing. For these reasons the minimum thickness for beds of the low-grade coals is set much higher in proportion to B. t. u. value than for beds of coals of higher grade. The minimum minable thickness of bed is fixed at 14 inches for all coals having more than 12,000 B. t. u. For coals having less than 12,000 B. t. u. the minimum minable thickness increases at the rate of one-tenth inch for each decrease of 100 B. t. u. down to 11,000, then at the rate of one-tenth inch for each 50 B. t. u. down to 10,500, then at the rate of one-tenth inch for each 25 B. t. u. from 10,500 1 Wisher, C. A., Depth and minimum thickness of coal beds as limiting factors in valua- tion of coal lands: Bull. U. S. Geol. Survey No. 424, 1910, pp. 56-62. 70 CLASSIFICATION OF THE PUBLIC LANDS. down to 10,000. The increase for coals yielding less than 10,000 B t. u. is at the rate of one-tenth inch for each decrease of 10 B. t. u. in the coal. The following table gives the thicknesses for B. t. u. of even five hundreds: Minimum thicknesses for even five hundreds B. t. u. B.t.u. | Inches. B.t.u. | Inches. B.t.u. |Inches. 15,000 14 12, 500 14 10, 000 18 14,500 14 12,000 14 9, 500 23 14; 000 14 11, 500 143 9, 000 28 13,500 14 11, 000 15 8,500 33 13, 000 14 10,500 16 8, 000 38 An important question that frequently arises is, What value, in relation to thickness, shall be given to split or broken beds? The general practice of the United States Geological Survey in classifying coals has been to give a split bed the value of an unbroken bed with which it can fairly be compared. It is evident that a solid 3-foot bed is worth more than two 18-inch benches separated by 6 inches of clay or shale. After careful study the Survey adopted the simple expedi- ent of prescribing that any parting or bench of bone or impure coal included in a bed injured the value of the coal of the bed in amount equal to the thickness of the parting. Thus the split bed just cited, with its 6-inch parting, is regarded as equivalent to a solid bed 30 inches thick (36 inches of coal minus 6 inches of parting equals 30 inches). If the benches: on either side of the parting are not of the same thickness the thickness of the parting is deducted from the thickness of the thinner bench. It is not necessary to consider the whole thickness of a coal bed. It is the practice of the Survey to start with the best bench, if in itself not of workable thickness, and to add the thickness of the next bench above or below after deducting the thickness of the intermediate parting. If the whole bed thus included is still not of workable thickness and more benches exist above or below, the thickness of these benches is added, after sub- tracting the thickness of the parting between them and the principal bench. If a parting is thicker than the thinner adjoining’ coal bench, that bench is considered as having no value. This practice is best illustrated by a group of concrete examples. (See fig. 2.) As a matter of practice two coal layers, each workable, are treated as parts of a single bed if the two layers both exceed in thick- ness the parting between them and the parting does not exceed 34 feet. In general two layers of coal are treated as two beds if the parting between them exceeds either one in thickness, and their work- ability is determined on that basis. CLASSIFICATION OF MINERAL LANDS. Toll 10” 10” 1/ 3g” "10" i a we gig! aig! Nl an 2" ie TT 7 a! ati" yom tae” 2 FigurE 2.—Diagram showing split or broken beds and their value for classification: a, measured thickness; b, equivalent thickness used in classification and valuation. 72 CLASSIFICATION OF THE PUBLIC LANDS. The criteria given in the preceding paragraphs are intended to determine the workability or nonworkability of a coal measured at any given point. The most difficult problem in classification is the determination, of the probable limits of workability of an irregular coal. Coal occurs in beds ranging in thickness from a fraction of an inch to 100 feet or more and in areal extent from a few square feet to thousands of square miles. Some beds maintain a nearly uniform thickness over hundreds of square miles. Others may be traced at the same geologic horizon over hundreds or thousands of square miles but vary greatly in thickness, ranging from a few inches to several feet or back again within a quarter of a mile. Every grade of regularity or irregularity between these extremes is found, and it is possible to determine the “ habit ” of some beds as regards regularity. The simplest problem is that in which two unequal measurements on a single bed, taken at different places, are available. All such beds are assumed to grade uniformly in thickness from the thicker measurement to or through the thinner measurement, and a limit to the workable coal is thus fixed that, while it may or may not agree with the unknown facts, is the most probable limit. In general, a coal bed that can be traced continuously along the face of a cliff, as can many beds in the West, has usually been assumed to extend under the land back from the cliff at least one-half the length of the cliff outcrop, the lens or bed having the shape of a half-circle, the length of the cliff outcrop being the diameter of the circle. Obviously, if the outcrop runs along the cliff for many miles, the extension of the coal back from the outcrop may be modified by many other factors, such as limit of depth, or outcrop on the opposite side of the hill. If the bed outcrops along the cliff with irregular thickness, only a moderate extension of the bed behind the cliff is assumed, the esti- mate being based on the character of the irregularities shown by measurements made along the cliff, or by a general knowledge of the extent of the lenses of that particular coal or of coals of that group, and depending on the general “habit” of the bed, if known, and also taking into account all local features. If the exposed outcrop does not extend in a straight line, but, as is more common, runs in and out of ravines, careful note is made of the thickening or thin- ning of the coal between one point of measurement and another in order to detect, if possible, any general tendency of the bed to thicken or thin in any direction, and all these measurements and tendencies are taken into account in determining the probable extent of the Jens in any direction. Many beds studied are known to be of less than workable thick- ness in larger or smaller part, and any measurement showing a work- able thickness on such a bed must usually be considered as a meas- ure taken at the center of a small lens of workable coal. A discovery CLASSIFICATION OF MINERAL LANDS. 13 or measurement of a coal bed by a well, or by drilling, will have the same value as an isolated measurement on the outcrop. The content and shape to be assigned.to any lens must depend on conditions and are largely matters of judgment, and such assignments or determi- nations especially require a wide knowledge of coals and of the par- ticular group of coals to which the bed under consideration may belong. To insure uniformity in treating the thousands of ques- tions of this kind that may arise—for nearly every field involves some, and many fields involve a great number—the Geological Sur- vey has gradually established a series of precedents, and in every question the attempt is made to reach conclusions by means of mathe- matical calculation. The limits of this bulletin will not allow the consideration of these methods here. DEPTH. Some of the facts about the deep mining of coal in this country and abroad have been presented and discussed in an earlier bulletin of the Survey... Not many years ago it was the common opinion and practice in parts of the West to consider as coal land only land on which coal actually cropped out, and requests are still occasionally sent to the Geological Survey asking the reclassification of certain land that had. been previously classified as coal land, the writers contending, and supporting their contention by abundant affidavits, that the land is noncoal, because no coal shows at the surface and none has been found on it in wells. If such land should be consid- ered noncoal land, however, most of the coal now mined in Illinois, Indiana, western Kentucky, Michigan, Kansas, and some other States comes from noncoal land, for most of the mines in those States are on lands where the coal mined does not crop out but is reached by shafts. The actual outcrop of most of the coal mined in these States is from 5 to 75 miles away from the shafts. Two questions are here involved: (1) How deep can coal be mined ? (2) Can all coals be mined to the same depth? Coal is now being mined to a depth of practically 4,000 feet (8,937 feet), and many shafts in England, Belgium, France, and Germany go deeper than 3,000 feet. Moreover, a consideration of the still greater depths to which substances other than coal are being successfully mined and a study of the deepest coal mines have convinced many of the best engineers of England and Europe that coal mining will be extended to 5,000 feet.2 The fact also that some of the largest coal com- panies of this country have purchased as coal land certain tracts under which the coal is believed to lie at depths of 5,000 to 6,000 feet 1¥Wisher, C. A., Depth and minimum thickness of beds as limiting factors in valuation of coal lands: Bull. U. S. Geol. Survey No. 424, 1910, pp. 48 et seq. 2Idem, p. 51. 74 CLASSIFICATION OF THE PUBLIC LANDS. shows that some American engineers believe that coal mining will © be carried to those depths, Although, without regard to profit, there may be a physical limit to the depth that coal can ultimately be mined, in general the depth of mining must be determined by its cost. Given a steady market the depth to which coal can be mined is a question that involves diminishing profits; every added foot of depth adds to the time re- quired to lift the coal, thus reducing the possible output of the mine, to the cost of the lift, to the initial capital required and the interest on that capital, to the size of pillars, and to other factors. Where coal is mined at a certain depth with a narrow margin of profit, obviously mining at a much greater depth will extinguish that margin and ren- der that coal unworkable until markets are better. Of two coals at the same depth, of the same thickness, and in other ways equal but of different quality, one, the better coal, may yield a profit and the other may not. A similar inequality of profit may exist between two coals of the same quality but of different thickness. The thicker coal, which can be mined at a less cost, may be minable at a profit, while the thinner may not. In brief, the depth to which any coal can be worked depends, on the one hand, on its quality, which de- termines the profits where the cost of working is the same, and, on the other hand, on the cost of mining, which, omitting differences due to depth, is in general proportional to the thickness of the coal. Therefore, given a certain grade of coal which sells on the market at a certain price the profit will be in inverse ratio to the cost of mining, and hence, other things being equal, the depth to which that coal can be mined will differ for different thicknesses of coal and is assumed to vary in direct proportion to the value of the coal as com- puted from the cost of mining. The depth to which any coal can be mined is therefore assumed to be directly proportional to the B. t. u. value of the coal and inversely proportional to the cost of mining for different thicknesses. Thus below the adopted minimum depth of 500 feet, a 10,000 B. t. u. coal can be mined to only two-thirds the depth of a 15,000 B. t. u. coal, and an 8,000 B. t. u. coal to two-thirds the depth of a 12,000 B. t. u. coal of the same thickness. If 5,000 feet 1s assumed as the maximum possible depth at which any coal can be mined, it is also assumed to apply only to coal of the highest grade and to the thickness costing the least to mine—in other words, to a 15,000 B. t. u. coal 6 feet or more thick. By this assumption a 6-foot coal of 12,000 B. t. u. is considered as workable to only 4,000 feet or a 6-foot coal of 10,000 B. t. u. to only 3,333 feet. Elsewhere in this bulletin it is Bae out that the cost of mining a ton of coal is much higher for thin beds than for thick beds. There is no great difference in the cost of mining coals between 6 and 10 CLASSIFICATION OF MINERAL LANDS. 15 feet thick, but, especially in the West, the cost of mining coals less than 6 feet thick increases as the thickness decreases. It has there- fore been assumed that a coal of the minimum thickness for its grade is workable to a depth of not more than 500 feet; that a coal 6 feet or more thick is workable to a depth of 100 feet for each 300 B. t. u. it contains; and that a coal between its minimum thickness and 6 feet is workable to a depth between 500 feet and the maximum depth limit for that coal proportional to the thickness above the minimum. Thus, a 12,000 B. t. u. coal 6 feet or more thick has a maximum depth limit of 4,000 feet and an assumed minimum thickness of 14 inches; a bed of 12,000 B. t. u. coal 4 feet thick is workable to a depth deter- mined by the rule above given as follows: 72—14:48—14::4,000— 500: 2; 22,050, which added to 500, the depth limit for a bed of the minimum thickness, gives 2,550 as the depth limit for the bed under consideration. The accompanying chart (fig. 3) is copied from part of a large- scale diagram used by the Geological Survey in classifying coal land. Tt is arranged to show the depth limit fixed for a coal of any B. t. u. value of any thickness under 6 feet. For convenience the readings for the even feet and for the even thousand B. t. u. are given in the following table: Limits of minable depth of coal of various thicknesses and various heating values in B. t. u. a a British thermal units.........-.----- 15,000 ; 14,000 | 13,000 | 12,000 | 11,000 | 10,000 | 9,000 8, 000 Thickness, in feet: a 3 811 787| 764 751 Se 51 EL a lL ea ee PAst ear a Teo) 1100) 2-000) © 825 |... 5. . oor sce cl Ld eee 2,200 | 2,075] 1,950] 1,830] 1,665| 1,440| 950|.......- 3,140 | 2,940] 2,740] 2/550] 2,340] 2,075| 1,650] 1,140 [ .., ie Sane ae eae 4,070 | 3,800| 3,540| 3,270] 3,000] 2,700] 2,330] 1.920 ua ll 5,000 | 4,666 | 4.330] 4,000| 3,660| 3,330] 3,000| 2.660 In general the limit of depth at which a coal bed may be profitably mined depends entirely upon the thickness of the bed and the quality of the coal. If, however, a thin but workable bed that lies below its ordinary minable depth is overlain by a thicker bed that lies within its own minable depth, the lower thin bed may, perhaps, be profitably worked by extending downward the shaft sunk to the higher, thicker coal, whereas the thinner bed could not have been profitably mined alone. A single shaft may also give access to all the coals of a group, and, though the cost of raising all the coal will be the same as if the coal were taken from a single bed, the cost of the shaft and the interest on that cost will be borne by the proceeds of a larger product. In some places the whole cost of a shaft may be borne by the coal of a thick bed that underlies several thinner beds 76 CLASSIFICATION. OF THE PUBLIC LANDS. or that lies in the middle of a group of thinner beds. It is clear that no two shafts that penetrate groups of coal beds will present Thickness of coal bed in feet. 0 I> 2 3 Bd <5 : 27 sO a ek Dad ae Re ine UB 00 ied Si a ad i |e eg Re ee ee ee ON Be eS en ee PP Hi i i a ie eb Dl eal aan egg ck of] HSN a NE | de Pee es A NS A SN I a FEE RNSCISEICSEREEEEE EEE Be, ENB cs ae deanna Own Toss emmm ne wooo} ANSI (SB GI RSE ES Ie aT Fe SAI SIE SG @ PRG oT i i lind il’ SSS Ul a li Ga EDEN EN NS a PSN) SE ERR eee ANS ea a a A MT NG Ec ne CECE CECA AARNE i i SN eh 5 fyo' aL | IIE NN NS Tes a ee Ae eISSN eee ee a SS NS 1,500 8,000 8,500 9,000 = 3000 10,000 Depth in feet wv () oO (D>) units sae EE OWNS EE he Diced ale PT ie led Na BN ENS ce Pa De ee eS SN ha ad be ee BS Ge ee ee See eee eee ewer wa ee Ee ee ee ee 3,500 j=) O1 (@) Lap) (ap) a Oo . BeEICISi “tie rnral ? 11,000 11,500 ho ? (17 £13,000 Mavic ea les ebacl oe Say oie os ae 9,000.6 : 3 3 mn 5 6 15,000 Thickness of coal bed in feet FIGURE 3.—Diagram showing depth limits of coals of different B. t. u. and of different thicknesses under 6 feet. similar conditions. The coals of such groups will vary in number from two to twenty or more and may be included in an interval CLASSIFICATION OF MINERAL LANDS. a | of 50 to 500 feet or more. Every case involving such conditions must be considered on its merits, and here again the Geological Survey has found it necessary to establish a series of general prece- dents in order to make its treatment of such cases reasonably uniform. In some places it has been found possible to treat a group of coal beds as if they were all gathered at a “center of weight ”—that is, at a point determined by multiplying the com- puted thickness of each bed by its depth from the surface and dividing the sum of the products by the sum of the compensated thicknesses, the thicknesses of the various beds being reduced for partings in the manner already described. The determination of the limit in depth at which a coal bed can be mined may be complicated by the fact that in a region of very rugged topography the coal gets below minable limit in passing ‘under some high ridge or peak but is within the minable limit under a valley on the other side. Again, in some places the coal outcrops near the foot of a great cliff, such as commonly flanks a high plateau in the West, and it goes below minable depth within a short distance from its outcrop. In order to cover all the different occurrences of this kind the regulations provide that tracts underlain by horizontal beds of coal that he at depths below the minable limit may under cer- tain conditions be classified as coal land. Horizontal beds of coal may be mined to a distance back from their outcrop equal to 10 times the depth limit for coal of that particular grade and thickness. It is evi- dent that, to be commercially minable at a certain depth, a coal bed must be minable for a reasonable distance from the foot of a shaft sunk to it, in order to pay the cost of the shaft. It is also evident that if it is profitable to sink a shaft to the depth limit for a given coal and then mine out horizontally by drift a certain distance from the foot of the shaft, it would be profitable to mine farther from the foot of the shaft if it were not so deep. The relative values involved in shaft and drift can be easily calculated if unit values are fixed for the horizontal and vertical components. For purposes of classi- fication and valuation it has been assumed that 1 foot of vertical shaft in rock involves as much expense in its construction and maintenance and in the removal of the coal as 7.5 feet of horizontal drift in coal. For this reason the horizontal distance to which the drift can be carried will be no more than the prescribed limit for mining from the outcrop (in this case set at 10 times the vertical limit) minus 7.5 times the depth of the shaft. Thus if the minable depth of a cer- tain coal bed is 2,000 feet, but that bed is horizontal and crops out in a cliff, the area underlain by it is classified as coal land for a dis- tance of 10 times 2,000, or 20,000 feet, back from the outcrop. If the bed is horizontal but les at a depth of 700 feet, it is assumed that the coal can be mined back 20,000 minus (7007.5) =14,750 feet from the 78 CLASSIFICATION OF THE PUBLIC LANDS. foot of a shaft of that depth, even if, away from the foot of the shaft, the coal is more than 2,000 feet below the surface. If the shaft is 1,200 feet deep the coal can be mined back 20,000 minus (1,200 7.5) =11,000 feet. If the coal is at the depth limit at the foot of the shaft it can be mined back 20,000 minus (2,0007.5) = 5,000 feet, or approximately 1 mile in any direction. CLASSIFICATION BY 40-ACRE TRACTS OR LOTS. In ordinary practice coal land is disposed of by parcels composed of “smallest legal subdivisions,” which are ordinarily quarter-quarter sections, or 40 acres, except along the north and west sides of town- ships and in areas bordering meandered rivers or lakes, where the tracts are usually irregular in size and shape and are called lots. The price of a tract that is wholly underlain by coal is the price per acre multiplied by the number of acres. The price of a tract that is only in part underlain by coal is the price of the coal per acre multiplied by the number of acres it underlies. To obtain the sale price per acre of the 40-acre tract or lot, the amount obtained by the above computation is divided by 40 or by a figure representing the actual acreage, but no land must be appraised at a price below the minimum fixed by law. Thus if 24 acres of a 40-acre tract is under- lain by coal valued at $50 an acre the price of the “ forty ” is 24 times $50=$1,200, or $30 an acre ($1,200-40=$30). The value of the coal in some lands, however, is so small that to charge even the minimum price for them would make the price of the coal abnormally high. For example, to take an actual case: Five acres of a 40-acre tract is under- lain by coal 2 feet thick, the total value of which under the regulations is about $100. The tract is within 15 miles of a railroad, and there- fore if it is all sold as coal land it must be sold at the rate of $20 an acre—that is, the whole tract must be sold for $800. The coal land in the forty is therefore segregated from the agricultural land, the line of division following the 10 or 24 acre subdivision. The two por- tions of the forty thus segregated are treated as separate lots. The 5 acres of coal land is sold for $100, its value, and the noncoal tract is subject to disposal as nonmineral land. Such a division of the forty into two lots, one coal and the other noncoal, is made only along the outcrop of the coal and only within so short a distance from known corners that, little doubt can arise as to the exact position of the outcrop. OUTCROP COAL AND BURNED COAL. In coal-mining practice it has been found that the coal along the outcrop and for a distance back of it ranging from 30 to 100 feet or more, the distance depending on the amount of cover, is more or less influenced by weathering, which materially decreases its value. Diffi- CLASSIFICATION OF MINERAL LANDS. 19 culty due to the thin and weak roof is also encountered in mining on the outcrop. If only a thin edge or corner of coal extends intoa forty it may be neglected, as it will give the tract no value as coal land. If the coal outcrops in bluffs or steep hillsides or has a high dip weath- ering may be neglected. If the coal outcrops at the top of a mesa or on the face of a long, gentle slope an allowance is made for thinness of cover. The possibility of mining outcrop coal by stripping with steam shovel or otherwise is generally considered, as such a method of coal mining has in many places proved highly successful. In many areas of the West the coal beds have been burned along the outcrop. In some places one or more or all of the beds have been burned not only along an outcrop over a whole field but under the flat tops of mesas where the coal is close to the surface. In a few places mining has shown that this burning extends back 1,000 feet or more and lies many hundred feet under cover. In general, how- ever, the coal does not appear to have burned back more than a few rods. All places where coal has been burned are indicated on the field maps. In classifying the land in these places the edge of the coal is fixed along a line drawn back of the outcrop, only slightly back of it where the line crosses ravines, but to a considerable dis- tance back of it where it crosses projecting divides, especially if the coal is under light cover. METHODS OF VALUATION.! COST OF COAL IN THE GROUND. The total cost of coal in the ground consists of the original pur- chase price, interest on investment, amortization charges, taxes, and, if the coal is leased, the cost of inspection and of collecting royalties. The following table shows the amortization and ultimate cost of coal in the ground per dollar of investment for periods ranging from 20 to 40 years, at 5 and 6 per cent interest. Ultimate cost of coal per dollar of purchase price. aa me Annual pen eee Annual : Total | of purchase Amortization period in years. pete arene taxes at aoe annual | price at : * 11 percent. SHAESS cost. end of Be. amortiza- tion period. Per cent 20 5 $0. 05 $0.01 | $0.03 $0. 09 $1. 80 OSS SOIT Ie a Te A ec ie la 6 . 06 -O1 . 027 . 097 1.94 30 { 5 -05 O01 .015 -075 2.25 Mimsy tes oF 6a ke eo 6 - 06 .O1 . 0125 . 0825 2.475 40 { 5 - 05 .O1 . 008 . 068 2. 88 a ew ap rie an nr ee 6 . 06 -O1 . 006 .076 3.04 1 For a more detailed account of the principles of valuation of public coal land see Survey Bulletin 424, on the valuation of public coal lands. 80 CLASSIFICATION OF THE PUBLIC LANDS. It is generally agreed that the price paid for coal in the ground should be recovered by the investor during the early years of the mining, when the cost is lowest. Otherwise it must be recovered when the inevitable increase in the cost of working the mine has re- duced the profits and the business has reached a condition that is the bane of the eastern coal-mining industry to-day. The initial invest- ment should invariably be refunded within the first 20 years of the life of the mine. The above table shows that if the mine is opened and operated immediately and continuously after purchase the total cost of the coal in the ground will be about two dollars for each dollar of the purchase price. The value of coal in the ground at the time of its extraction is measured by the current royalty rate in the region where the coal is situated. Its value at the time the mine is opened is, then, approximately one-half the royalty rate, as has been indicated. Were it possible to know in advance the exact num- ber of tons that would be recovered from any acre of land, the value of that acre at the beginning of mining would be one-half the royalty rate per ton multiplied by the tonnage recovered. If the royalty rate is 10 cents a ton, the value of coal per ton in the ground when a mine is opened is at least 5 cents. To insure profit and safety, — however, the purchaser of coal land, as a rule, in buying demands a margin on the estimated tonnage value (1) as a consideration for the risk of the investment, (2) to offset possible delays in the mining of the coal, and (8) as a contingent against an overestimate of the recoverable tonnage. If this margin is fixed at one-half the esti- mated value, the coal should have a sale value of 24 cents a ton if the royalty is 10 cents a ton. Royalties on bituminous coals in the United States range from about 3 to the equivalent of 35 cents a ton. A comparison of royalties paid in the United States, some of which are given in Survey Bulletin 424 (p. 10) shows that 10 cents a ton is not far from the average royalty paid under private leases—some- what less in the East, somewhat more in the West. Therefore 24 cents a ton is a fair sale price for unmined coal that is to be mined immediately, where 10 cents a ton is the prevailing royalty. As a matter of fact, where the character and tonnage of the coal are well known to both buyer and seller prices often range from one-quarter the royalty rate almost or quite to the royalty rate. For example, the Pittsburgh coal, in southwestern Pennsylvania, is worked to a thickness of about 7 feet. On an estimate of 1,200 tons recovery per acre-foot this bed should yield 8,400 tons an acre; yet it is reported that 99 separate transfers were made in Westmoreland County be- tween 1901 and 1910 at an average price of $1,102.70 an acre—over 13 cents a ton—and many of these sales were made at a price much higher than this average. Occasionally the sale price for small tracts adjacent to operating mines may reach the royalty rate. CLASSIFICATION OF MINERAL LANDS. 81 The general impression that coal lands are sold at low prices is due largely to the fact that in the past most of the sellers had bought their land as farm land, knowing little or nothing of its coal content or value, and had regarded the coal as a little overmeasure on the part of nature for which they were willing to take anything that was offered or that looked good to them. As a result a large number of the recorded sales of coal land have been made at prices that have had little relation to the value of the coal, and in the past a large percentage of the total acreage has been sold at such prices. A recent review of coal-land sales for one year, as recorded in one of the most reliable of the coal journals, excluding all sales of tracts containing over 10,000 acres, which were obviously bought for holding or specu- lation, showed 40 sales, representing a total of 95,218 acres, at an average price of $209 per acre. This average price for a year’s sales shows the great extent to which coal lands have passed out of their original farmer ownership. Grouped according to prices, it is found that that year’s sales.as thus recorded ran as follows: Prices of coal lands sold in one year. Price per acre. Sales. | Acres. ia aw wtp ale) ~ amiga =p-j~ lm ne quite S yep ele Padi mee Saleen se 3 10, 198 So ie ie ia saw are or raw ines dete twcecss geelsceurstsenedececes 2 1, 633 NR se ico ta mer~ nao SoS ates bie oi aie mi atwseien we sig de seins sie ee dese e eens 3 417 ae ec a cle oie Sin wen so anie a cle Pacis eres chances nem Ned ae leks eewees 8 14, 046 Sr PE i on hi ois ain aking cS 6 ee bwin pic ieee a Sainte eee sing ee one 10 26, 097 eee EN EE Ete cine aS cee ele coe Oboe eowe we teee nbecevsobyececasevees 14 32, 817 In other words, 65 per cent of the sales and the acreage were at $100 an acre or more and 40 per cent of the sales were at $200 an acre or more. It is evident that a large share of these were sales of lands not purchased for immediate development. Sixteen of these sales, con- veying 74,633 acres, covered tracts containing more than 1,500 acres, an area generally admitted to be as large as can be economically mined from one plant in present-day practice. In order to give the prospective buyer an ample margin of safety, the basing prices of the Government coal lands are fixed at only 40 per cent of the value (24 cents per ton) named in a preceding para- graph, or at 1 cent per ton for a coal of good average quality—say 12,500 B. t. u.—equivalent to one-tenth of a cent for each 1,250 B. t. u. of the coal. This price is one-tenth the assumed average royalty rate. FACTORS INVOLVED. The valuation indicated, however—1 cent per ton for coal in the ground—is not put on all coals indiscriminately. Though the value of any coal is most readily obtained by taking the royalty rate, 78894°—Bull. 587—183——-6 —— $2 CLASSIFICATION OF THE PUBLIC LANDS. the royalty rate itself 1s based on the average difference between the cost price of the coal ready for sale and the sale price—that is, on the profit. If competition is keen and the profit is low, these facts are reflected in a low royalty rate. Whatever affects the profits affects the royalty rate and correspondingly the value. Other things being equal, the lower the grade of coal the less readily it sells and the less the profit, the royalty, and the value. On the other hand, the more expensive the coal is to mine the less the profit, the royalty, and the value. The Government valuations can not take account of changes in competition, markets, transportation facilities, or freight rates, or other factors that affect the profit, but it can and does take account of the quality and character of the coal, both chemically and physically, which affect the sale price and so the profit and value, and of those natural factors that affect the mining cost. The most important of these factors are thickness and accessibility. EFFECT OF QUALITY ON PRICE. One cent per ton is therefore the price put on a good average coal— a. noncoking bituminous coal of 12,500 B. t. u. heat value, 6 to 10 feet thick, and at the surface. For coals of other B. t. u. value the same rate of one-tenth cent for each 1,250 B. t. u. is applied, and provision is made for increasing this value (not to exceed 100 per cent) for coking coal or coal that has special qualities which enhance its value in the market, the percentage of increase depending on the quality of the coke it yields or the extent to which its special qualities en- hance its value; and on the other hand provision is made for reduc- ing the appraised value because of special impurities, such as sul- phur, or because of physical defects that obviously detract from the market value. EFFECT OF MINING COST ON PRICE. The cost of mining coal is affected by many factors—such as cost of prospecting, shaft sinking, or other mine opening, surface and under- ground plant, perhaps community plant, water, supplies, timber, feed, and insurance—all of which vary from place to place or in accordance with the method of working the mine. Within the mine the main factors are mining rate, thickness, depth, and dip or pitch of bed, variations or irreguarity in thickness, partings, “sulphur ” or other impurities that must be removed, kind of roof or floor, presence of gas or water, provision for drainage and ventilation, haulage and hoisting, faults, and igneous intrusions. Many of these factors give rise to problems for the engineer; others definitely affect the value of the land for coal mining. One of the factors of the latter class—thickness—has so definite and constant a relation to the cost of mining that it must be taken into account in determining the value of all coal land. CLASSIFICATION OF MINERAL LANDS. 83 VALUE OF THIN COALS. The cost of mining thin coals increases rapidly with the decrease in their thickness, for the following reasons: The rate paid for min- ing the coal increases with the thinning of the bed, as do the amount of dead work per unit of output, the cost of trackage, ties, rails, haul- age, and ventilation, and, for the very thin coals, the cost of taking up floor or brushing down roof to obtain height. H. M. Chance? has prepared curves expressing the relations between mining cost and thickness for anthracite coal. The figures showing Chance’s determinations are given in column 2 of the table on page 84. Similar figures (column 3) were obtained by the Survey for bituminous coals. Detailed cost. sheets of mines working coals of different thicknesses were taken and the costs were separated into four items—(a) capital cost (interest, etc.); (@) mining rate; (c) tonnage cost (proportional to output, tipple, office, etc.) ; (d) acreage cost (proportional to acreage mined out, dead work, hauling, etc.). Obviously, if the recovery per acre-foot is the same, the last item would be double for a 5-foot coal bed what it would be for a 10-foot bed yielding the same output and would be inversely proportional to the thickness of the bed. Though the tonnage recovered is greater per acre-foot from thin than from thick beds, yet the recovery varies so greatly from mine to mine and from time to time that an absolutely invariable recovery from a bed of a given thickness can not be assumed. Therefore, in reaching the results now to be stated, differences in recovery from beds of different thickness have not been considered. As in all studies of coal mining made by the Geological Survey the obtainable figures relating to any particular factor were, if possible, gathered together and platted graphically on a chart, by which it has usually been practicable to show certain definite averages or curves expressing the relation sought. Whenever possible, these curves have been reduced to mathematical formulas. A concrete example is a curve showing the relation between the min- ing rate and thickness of bed, a relation which it was necessary to de- termine in working out the total cost of mining beds of different thicknesses. In making this diagram the mining rates at different places in the United States were platted on cross-section paper as shown in figure 4 (p. 85), on which the curve A-B was drawn to ex- press the average relation between these two factors, a relation which was used in later computations. 1 Chance, H. M., The cost of mining coal: Eng. and Min. Jour., May 29, 1909, pp. . 1099-1101. 64 CLASSIFICATION OF THE PUBLIC LANDS. The following table gives the derivation of the formula showing the relation of the thickness to value of bed,.uniform recovery being assumed : Vable showing derivation of formula for relation of thickness to value of bed. Average cost. Ap- Differ- Thick- proxi- ence= |Square| 100 ness of mate | Value 10 of minus bed in | a nthra- ; com- | by in- | minus jamount|amount Oo eid Bitumi- pine version.| thick- | in col- | in col- t). nous. ion ness |umn 6. |umn 7. (Chance). cost. in feet. 1 2 3 4 5) 6 7 8 10 1.00 1.00 1.00 1.00 0 0 100 9 1.01 1.03 1.02 97 1 1 99 8 1.045 1.075 | 1.05 95 2 4 96 fi 1.10 1.126 | 1.10 91 3 9 91 6 1.18 1.20 1. 20 . 83 A 16 84 5 1.35 1.30 1.33 (5) 5 25 75 4 1.65 | 1.45-1.55 1.50 - 66 6 36 64 3 2.13 2. 2.00 00 7 49 ol 2 3.36 3.00 3.00 33 8 The first column in the table gives the thickness of the bed in feet ; the second the average cost of mining anthracite at these thick- nesses, according to Chance (not including breakerage charges) ; the third column, the computed relative cost for bituminous coal; the fourth column, the approximate combination of the two; the fifth column, the relative values of beds of the same quality of coal of different thickness, obtained by dividing 100 by the cost, given in column 4; the sixth column, the difference in feet between 10 and the particular thickness given; the seventh column, the square of the numbers in column 6; the eighth column, the result of sub- tracting from 100 the square of the difference between 10 and the thickness in feet. By comparing columns 5 and 8, column 8 is seen to give a close approximation to the computed figures in column 5, and as the figures in column 5 are by no means absolute and fixed the figures in column 8 have been taken as fairly expressing the relative value of different thicknesses of the same coal; but this is found by subtracting from 100 per cent a percentage equal to the square of the differ- 100. 000) ia 2. ence between 10 and the thickness, or [00 a ae The value per ton of a bed less than 10 feet thick of a given grade of coal may therefore be found by multiplying the normal value per ton for a 10-foot bed of coal of that erade by (1 mh a): In valuing land by the acre-foot, however, an additional factor must be considered, namely, that a larger recovery of coal per acre- foot is possible from thin beds than from thick beds. This difference offsets in a measure the rapid increase in mining cost with thinning of beds. Thus 1,000 tons an acre-foot for a 10-foot bed and 1,200 CLASSIFICATION OF MINERAL LANDS. 85 tons an acre-foot for a 6-foot bed are considered fair recoveries. But 1,000 tons of coal at 1 cent a ton is $10, and 1,200 tons at 0.84 cent a ton (84 per cent being the corresponding value of a 6-foot bed) is $10.08. It is then practically immaterial whether land containing a 6-foot bed is valued at 84 per cent of the normal value of land con- taining a 10-foot bed of coal of a certain grade and an assumed recovery of 1,200 tons an acre-foot or whether the same value per ton and the same recovery per acre-foot are assumed as with the 10-foot bed. As the latter treatment is the simpler it has therefore ~~ SE om Thickness of coal bed in-feet "25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 iS 120 125 130 135 Mining rate in cents per ton for bituminous coal Fieurr 4.—Rates paid in the United States for mining coal of specified thicknesses and curve (A—B) showing average relation between mining rate and thickness. 1, 2, 3, Wyoming, southern fields, run of mine, agreements of 1912. 4, 5, Colorado, north- eastern coal fields, run of mine, agreements of 1912. 6, Montana, Red Lodge field, run of mine. 7, Indiana, miscellaneous agreements, run of mine. 8, Indiana, block coal agreements, screened. 9, Michigan, summary of agreements of 1910. 10, Missouri, Summary of agreements, run of mine. 11, Missouri, Bates and Vernon counties, run of mine, agreements of 1908. 12, West Virginia, summary of agreements, screened, 13, Kentucky-Tennessee, Jellico mining district, screened. 14, Tennessee, Durham Coal & Iron Co., run of mine. 15, Tennessee, summary of agreements, run of mine. been adopted and the value of a ton of any coal in the ground is taken as constant for thicknesses between 6 and 10 feet. The rate of increase in cost of mining a bed less than 6 feet thick, however, is too great to be compensated for by the greater recovery per acre-foot. After making various assumptions as to fair average acre-foot recovery for thin coals—assumptions based on known recov- eries—and after computing the value of the coal in thin beds, accord- 86 CLASSIFICATION OF THE PUBLIC. LANDS. ing to the formula given on page 84, it was decided to avoid a sliding scale both in value and recovery by reducing the value of beds less than 6 feet thick 10 per cent for each foot below 6 until the minimum for that coal is reached. Thus the coal in a 5-foot bed is computed at 90 per cent of the value per ton of the coal in a 6-foot bed, the coal in a 3-foot bed at 70 per cent of the value per ton of the coal in a 6-foot bed, and so on. This reduction for the value of the coal in beds less than 6 feet thick is readily computed by multiplying the normal value per ton by = where Z is the thickness in feet. Figures showing the results obtained by multiplying the relative value of coal in thin beds, given in column 8 of the preceding table, by various assumed rates of recovery were plotted on cross- section paper and an arbitrary line was drawn through the middle of the group of lines so obtained. This line is practically a straight line, giving a reduction in value of 10 per cent for each 1-foot reduc- tion in thickness, and was accepted as representing fair average relative values. Sufficient data were not at hand on the relative cost of mining coals more than 10 feet thick to lead to definite figures, or figures having more than approximately authoritative value. It is, however, gen- erally recognized that the cost of working coals does not continue to decrease indefinitely as the beds increase in thickness, for the in- creased cost of timbering and increases due to other practical diffi- culties gradually overcome the gain due to smaller acreage, and in- creases for the thick coals in general probably entirely offset that gain. From beds more than 10 feet thick, other things being equal, the recovery per acre-foot decreases with increase in thickness, owing to the necessity of leaving larger pillars and the difficulty of reaching all the coal. It has therefore been assumed that the recovery dimin- ishes on each additional foot above 10. Thus a 16-foot bed takes first the normal value on 10 feet; next the eleventh foot is valued at only 99 per cent of the value fixed for the tenth foot, the twelfth foot at 98 per cent, and so on, the sixteenth foot having a value of only 94 per cent of the value fixed for the tenth foot. In computing acre values on beds over 10 feet thick it has been found best to use the normal basing value in cents per ton of a 10- foot bed and assume the same recovery per acre-foot and then com- pute the thickness (¢’) of a bed that without deduction will yield the same acreage recovery as the bed in question. Where the thick- ness in feet (¢) is more than 10 the equivalent thickness (¢’) is ex- pressed by the following formula: f=94 "(2 — sete : CLASSIFICATION. OF MINERAL LANDS. 87 Summarizing the above: The Government price per ton for a bed 6 to 10 feet thick will range from 6.4 mills (0.64 cent) for an | 8,000 B. t. u. coal to 1.2 cents for a 15,000 B. t. u. coal, but if a coal is of coking quality its price may be increased to a maximum of 2.4 cents, or if its quality is low it may be decreased to one-tenth cent or less. In computing the thickness of a split or broken bed for valuation the same allowance is made as in considering classification. The following table gives the computed value per acre of ordinary coal beds of different B. t. u. and different thickness: Normal price per acre of coal land containing one bed of coal with heat values from 10,000 to 15,000 B. t. u. and thickness from 1 foot 6 inches to 50 feet. Price per acre. * Tons per Equivalent Acre at Actual | computed) ji9 099 | 11,000 | 12,000 | 13,000 | 14,000 | 15,000 | 1 : : F 750 thickness. | thickness. | po}: | B. tu; t.u.; | B.t.u;| B.t.u.; | B.t.a.; | tons per 0.8 cent | 0.88 cent | 0.96 cent |1.04 cents |1.12 cents |1.20 cents | acre-foot. per ton. | per ton. | per ton. | per ton. | per ton. | per ton. —_————————— |__| | — | | | Ft. in Fit. in eG @ $6. 60 @ $7.25 @ $7.93 a $8.58 a $9. 25 a $9. 90 2, 625 2 Ward a 9.60 a@10.56 | @11.52 @ 12.48 a 13. 44 @ 14.40 3,500 3 Dew t a 16.80 a 18.50 20.15 21.85 23.50 25. 20 5, 250 4 3: 2 25.60 28.16 30. 75 33.30 35. 80 38. 40 7,000 5 45-6 36. 00 39. 60 43. 20 46.75 50. 40 54. 00 8, 750 6 6 48.00 52. 80 57.60 62. 40 67.20 72.00 10,500 it if 56. 00 61.60 67. 20 72.80 78. 40 84. 00 12, 250 8 8 64. 00 70. 40 76. 80 83. 20 89. 60 96. 00 14,000 9 9 72.00 79. 20 86. 40 93. 60 100. 80 108. 00 15,750 10 10 80. 00 88. 00 96. 00 104. 00 112. 00 120. 00 17,500 20 19 5 155. 60 171.20 186. 72 201. 94 218. 00 233.30 35, 000 30 271 A0 223. 40 245. 60 268. 00 290. 00 312.50 334. 80 52,500 40 ap! 282.70 311.00 338. 30 367.50 395. 00 423.00 70, 000 50 46 9 374. 80 412. 00 449. 00 486. 50 525. 00 562. 00 87,500 a Where the computed value is less than $20 the minimum prescribed by law is placed on the land— $20 if the lands lie within 15 miles of a railroad and $10 if more than 15 miles from a railroad. VALUE OF IRREGULAR BEDS. If the calculated thickness of any coal bed or group of beds snows a considerable variation in thickness and shows that this variation is not regular, it must be recognized that on any 40 acres concerning which no data are available the coal may be as thick or as thin as the maximum or minimum measured in adjacent areas. Because of the limited acreage that one purchaser may now legally buy and because he may not exchange his land for other land if it proves not to be underlain by as much coal as had been estimated in de- termining its price, an allowance should in fairness be made to him for possible local thinning. If any regularity is shown in the changing thickness of the coal. the practice is adopted of drawing lines of equal thickness, a feature 88 CLASSIFICATION OF THE PUBLIC LANDS. best illustrated by giving a concrete case, such as is represented in figure 5. | On this map lines were drawn from the position of one measure- ment to the position of each adjacent measurement and-the thick- ness was assumed to grade uniformly from one to each of the other points. Valuation is then based on the average thickness thus found for each forty that is being valued. If the measurements do not show any regularity in the change of thickness, the Survey has adopted a method of computing thickness that permits the thickness of the coal under any tract of land to be considered as less than the average of the measurements, in order to favor the buyer, for the reasons already stated. For while the coal is as likely to be above the average as below and, mathematically, is more likely to be just the average thickness than any other, yet a cautious buyer bargain- ing for coal would always want to discount the probability a little, as a matter of safety. If ail the measurements on a bed indicate the same thickness, that thickness may be safely taken as the thickness of the coal ynder any land included by the measurements. If the measurements vary but slightly from the average, the thickness un- der the land where no measurements are obtained is not likely to be much below the average. If, however, the variation is large, the coal in some places may be even thinner than the smallest measure- ment; yet to assume that the coal under all the land where no actual measurements were made is as thin as the thinnest measurements obtained would be overcautious. A more probable thickness is ob- tained by multiplying the average of the measurements by (1— Se) in which § isthe sum of all the measurements and SD is the sum of the numbers obtained by subtracting from the average each measurement below it or subtracting the average from each measurement above it. For example, if the measurements on a given bed in a certain area are 4 feet, 5 feet, 7 feet, 3 feet, 4 feet, 8 feet, 5 feet, 2 feet, 4 feet, 2 feet, 6 feet, and 10 feet, the average of all the measurements is 5 feet; the sum of the measurements is 60 feet; the difference be- tween the several measurements and the average 5 feet is 1 foot, 0,2 feet, 2 feet, 1° foot, 3° feet, 0, 3° feet, 1° foot, 3 feet! neem 5 feet, which added together give 21 feet; so 21 feet divided by 60 has been called the “ modulus of irregularity ” and has been adopted as a factor of safety ; 1-2 or 100 per cent—35 per cent=65 per cent; 65 per cent of 5 feet = 34 feet; therefore 34 feet is taken as a safe average thickness on which to sell the coal—in other words, the thickness which it is highly probable will be reached or exceeded by the coal under any of the land within the area of the measure- CLASSIFICATION OF MINERAL LANDS. 89 28 ; 27 Isopachous lines Coal crop,and area underlain by the coal bed Coal measurements (thickness in inches) iO \t goNS AS sae ve Sard aa “ees te am | | Seem | | | a ee Figure 5.—Sketch map showing lines along which a coal bed is of equal thickness (isopachous lines), drawn for use in the valuation of coal land. Bore hole and wel] records 90 CLASSIFICATION OF THE PUBLIC LANDS. ments given. In this, of course, the Government is favoring the buyer to the extent that the computed safe average is below the actual average of measurement; but, on the other hand, it is believed that this is no more than would properly be demanded by the aver- age purchaser of private coal lands who, knowing the measurements of thickness on the land to be purchased, wishes to safeguard himself against the possibility that the measurements will prove to be above the average of all of the coal. This safeguard is, of course, in addi- tion to the allowance for such a possibility in the purchase price. VALUE PER AORE. The Government prices for coal land are based on an assumed possible recovery of 1,000 tons per acre-foot. As an acre of coal a foot thick contains 1,750 to 1,800 tons, this recovery represents about 60 per cent of the coal in the ground. This percentage was long used in commercial estimates, though at present it is usually much exceeded by the percentage actually recovered in all good coal min- ing, especially in the bituminous fields of western Pennsylvania and in many regions in the Central West where the longwall method of mining has been practiced, by which the recovery in many places is estimated at 90 per cent or more. Although a recovery of 1,000 tons per acre-foot is fixed in the regu- lations and is used in all computations, the value per ton assumed for coals thinner than 6 feet or thicker than 10 feet recognizes the re- covery of more than 1,000 tons per acre-foot for coal in thin beds and of less than 1,000 tons per acre-foot for coal in very thick beds, thus avoiding the use of a variable recovery factor in making individual computations. : If more than one bed underlies a tract of land the early rule in valuing was to take the normal value of the bed likely to be worked first, 60 per cent. of the value of the bed next worked, 40 per cent of the value of the next, and 30 per cent of the value of any others, the reduction being made on the beds not worked at first to allow for interest on the investment for the long period during which they re- rnained in the ground. Fuller consideration of this subject, how- ever, and closer study of the operation of many mines that work several beds simultaneously or one immediately after the other and of the practical advantages of using the same plant for working beds either simultaneously or successively have led to the belief that these advantages more than outweigh the added interest that accrues dur- ing the longer period of holding. Accordingly, under the regulations now in force, consideration is had only of the total quantity of coal in the ground, no reduction being made for interest on the investment if, after allowance for CLASSIFICATION OF MINERAL LANDS. 9] the reduced value of the thin beds, the sum of the thicknesses of the beds does not exceed 10 feet. If the total thickness of the coal under a tract of land, after reduction for thin beds and for partings, is more than 10 feet, the total value of the coal is computed by the formula previously given for computing the value of thick beds. REDUCTION FOR DEPTH. It has been pointed out that the determination of the depth to which a coal may be profitably mined is a problem involving the consideration of diminishing profits. If a coal that is being mined near the surface is yielding a net profit of 25 cents a ton and if the cost of mining it increases 1 cent a ton for every 100 feet of increase in depth (purely an assumption), it is evident that the profits will disappear when the mine has reached a depth of 2,500 feet, so that the coal becomes unminable at a reasonable profit at some point of less depth, say 2,000 feet. Obviously anything that increases the profits—such as a gain in quality—will increase the depth of profit- able mining, and anything that decreases the profits—such as an in- crease in the cost of mining—will decrease the depth of profitable mining. If depth limits are assumed for coals of different grades and differ- ent thicknesses, it may also be assumed that the cost of mining in- creases uniformly with increase of depth, though it is strongly sus- pected that the cost of mining increases at an accelerating rate as the depth increases, but as sufficient data to prove this are not avail- able a uniform rate of increase has been assumed. If a certain coal has a normal value at any depth‘within 500 feet of the surface its value has been assumed to reach zero at its depth limit, and its price has been decreased uniformly from a point where it goes below the 500-foot depth down to its depth limit. If, for example, a bed has a value of $60 an acre at the depth of 500 feet and its depth limit is 2,500 feet, and if it reaches its depth limit 3 miles beyond the point where it lies at a depth of 500 feet, its dip remaining constant, it loses a value of $60 in crossing twelve 40-acre tracts, or $5 for each forty. The successive forties underlain by this coal would therefore be valued at $55, $50, $45, $40, $35, $30, $25, and thence to the depth limit at $20. Ordinarily the depth of a bed does not increase uniformly to its limit, but its steepest pitch or dip is at its outcrop and its dip grad- ually lessens toward the center of the basin in which it lies. Its depth at all places is indicated on the field sheets by contour lines representing uniform elevations above sea level. From these contour lines it is possible to compute the average depth of the bed under any 40-acre tract, and, the rate of diminishing value having been ‘OATS WY. ‘yavyo oY} JO Saspo oY} WO [[eJop OY} Jo YOnuT s}Iw0 yey Supers. MOAT 99 CLASSIFICATION OF THE PUBLIC LANDS. established by dividing the difference between the depth limit and 500 feet by the normal value at the surface, each 40 acres can be DOLLARS PER ACRE & See aE AUAOI ST 9 re EE fe 4 li Re L : E ae ats iE E a f [ C B eee E Y RB A a YW BERS 62 Ee BeBe ee ee aS ae ee a Sau ===SUNSEEEREES SUUEREREIUOEREEEUOEEEEIGE | | SESRERE Se SSP Ran SSE CEES EE EEE a | moe BES FHP NNRSERSSSE PEELE PERLE PEEP EEE EEE | ANAN pe ai aes Bei HMMMHENKS SCR SRSRSSE RES ERR EES Bod bl lead ES NE Sab SCOT | NNN oO PU VIAL A VV IZNEN SSeees SeNtns Runs MEUREEE SREEREREBS=" > RIEHL GRATE NESS eee EER REEEE EPPS EE SE me Sess Ri | > J eee a 24 VAL Zee, avard LA 74 TA 7-2 LA A Alaa |_|Z mv V | Ae ett) |_|7 | yi bel al | saan Hf |_/| ra A Ie Anne ad arparey cesvestact at cess sefanstsaeat UY HH SAAT ALDINE RE PE RCLn be MMIGMMuHE BUZZ 277A WNESSENESGESERECUEUBSSEREERD iieree VIZ IA VN NE NOSNSNERGERSEERSEREESSEEEE HAC NSS IS RGRNERNGHESNERE ESS. 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Aq posn uRiseip Jo dod poonpory KN ALAN Z| KX ss » / AVA LAS, AR IN KIALZ tL tiv ra ee ‘es na I\ V4 LICK Seaaeue: | DE 1 SJU9942-] AVN NOL Yad ALVY rh EAS YZ ANRYA2 NIN PRPRY Ruueanateacaueanarar anes PURDRPRPRP RDA -0u0 {SpuUR] [VOD Jo oON[RA 3 DOLLARS PER ACRE valued accordingly. The average depth of coal in a forty that is crossed at an angle by the outcrop or the depth-contour lines is the depth at the geometrical center of the area underlain. a eS ee ee ee bh i te CLASSIFICATION OF MINERAL LANDS. 93 If the dip of the coal bed whose value is given above had not been regular the rate of its diminishing value would have been —— =$1 for each 334 feet, so that if the depth under a given forty averaged 1,600 feet, the value of the forty would be g¢0 — 1800= 500 _ gov, 303 If more than one bed of coal underlies a 40-acre tract and the beds are not close together each one is valued independently and the value of the forty is taken as the sum of the value of the independent. beds. If several beds occur in a group a normal value is figured out for the group and this value is reduced according to the depth. In fixing the value of a group of dipping beds allowance is made for the change in the value of the group due to the lower beds passing below the 500-foot, line before the higher beds and reaching the depth hmit before they do. Formulas have been worked out to facilitate the calculation of the value of beds involved in some of the more common types of computations in these cases are read directly from large diagrams. These diagrams contain so much matter that a reproduction of one of them (fig. 6) on the reduced scale necessary for publication in this bulletin does little more than give a general idea of their char- acter, particularly as they are too involved to permit their descrip- tion in a bulletin that is not intended to set forth details of classifica- tion. ALLOWANCE FOR FAULTS. Faults—that is, breaks in the rocks involving a movement of beds on either side of the break—occurring in a coal field depreciate the value of the coal for mining and in places may render it entirely unworkable. Small faults may be disregarded unless they are so “numerous as to render the coal expensive or difficult to mine. If,. however, the throw of the fault is large—that is, if the edges of the beds that are broken have been so far separated by movement at an angle to the bedding that entries can not handily be driven from the coal on one side of the fault to the coal on the other—the value of the land is clearly less than that in which there is no fault, its emaller value being due both to the extra cost of recovery and to possible crushing of the coal along the fault planes. The price of coal in such places is determined by considering the two parts of any forty traversed by the fault separately, and giving the normal price to the part having the higher value and 40 to 95 per cent of the normal price to the part having the lower value. From the total thus obtained 5 to 15 per cent may be deducted to allow for crushing along the fault plane. 94 CLASSIFICATION OF THE PUBLIC LANDS. EFFECT OF INTRUSIONS. Intrusions of igneous rock may affect a coal bed favorably, as where they occur in sheets close above or below the coal and have had the effect of changing it from a bituminous or lower grade of coal to an anthracite. The physical character and B. t. u. value of such coals reflect amply the favorable results of the intrusion. More often the intruded masses of igneous rock are in the form of more or less vertical dikes that cut the bed in various directions. Obviously these dikes detract from the value of the bed by increasing the cost of mining, and an allowance is made in the final price in accordance with their character and extent. ALLOWANCE FOR OTHER FACTORS. In addition to the factors that have been specifically considered, many other factors are taken into account in valuing the land in any field. Of these the one for which the largest allowance is likely to be made is that of uncertainty. In some fields it has been possible to obtain measurements on the coal along its outcrop at points a quarter of a mile or less apart, and some of these measurements are supplemented by others made in drillings at points “ back ” from the outcrop, so that in such places it is possible to determine the “habit ” of the bed with some degree of certainty. In other places, especially in coal fields covered with a blanket of glacial deposits, or in broad valleys where the coals are under an alluvial cover, or in other fields where, owing to almost continuous burning along the outcrops, it is difficult to get accurate information as to the thick- ness of the beds, an allowance is made for uncertainty—an allow- ance that may take the form of a greatly reduced estimated thickness of the bed or, as is more common, of a restriction of the assumed area of workable coal. It has been found that the coal of certain fields was originally deposited with more regularity in some belts and areas than in others, and in many places the coal was deposited with great regularity around the edge of a basin but not in its center. Allowance is made for the possible thinning of the coal in all such places if exact data are not at hand, and the tract is classed either as noncoal land or as coal land of the minimum value. Many other factors are taken into account, such as known poor roof or floor, which may seriously affect the cost of mining and the value of the coal in place. Allowance is made for the extra cost of mining beds that include partings by making deductions for partings, it being assumed that the extra cost due to the partings eats up the profits on an equal thickness of coal. CLASSIFICATION OF MINERAL LANDS. 95 REDUCTION FOR DISTANCE FROM RAILROAD. Distance from railroads very largely affects the value of coal land. In fixing the value of Government coal land, however, distance from railroads is not taken into account, their value being based on that of the coal itself, but, in accordance with the law, the price so fixed is automatically reduced one-half for all lands lying more than 15 miles from a railroad in operation. Some land that contains coal beds, though within 15 miles of a railroad, can not be reached by a rail- road switch without going either around or over a high moun- tain, so that by either route its distance from the railroad practically exceeds the 15-mile limit. Such land is treated as if it were beyond the 15-mile limit and its price is reduced one-half, though not below the legal minimum—$20 an acre. MAXIMUM PRICE. In view of the uncertainty that may exist concerning many features of an undeveloped coal field, even if the evidence seems conclusive that it contains a large volume of coal, the maximum price of coal land is fixed by the regulations at $300 a nacre, except that if the field in which the land is situated contains very large mines, and if the coal is well known in the market and its adaptability to different uses has been demonstrated, the price of the land is computed from the value of the coal it contains, whether it exceeds $300 an acre or not. REVIEW OF CLASSIFICATION. According to the regulations the classification of any land as coal land is subject to review by the Secretary of the Interior, but the person making the application for review must present facts that show clearly and specifically that the land is not coal bearing in the sense of that term as it is defined in the regulations. The facts set forth in nearly all applications for review and reclassification of coal land simply show that no coal can be seen outcropping on or close to the land and that no coal has been found in drilling wells for water on or near the land. Before such applications are filed request should be made of the Geological Survey to state the basis of the classifica- tion, for a large percentage of the coal land has been classified as such because it is underlain by coal at depths of 500 feet or more, whereas the rocks at the surface contain no coal and may be of entirely different age from the underlying coal-bearing rocks. Data presented in a request for reclassification have determinative value only if they differ from data already in the records of the Geological Survey. 96 CLASSIFICATION OF THE PUBLIC LANDS. REGULATIONS FOR THE CLASSIFICATION AND VALUATION OF PUBLIC COAL LANDS. The following regulations were approved February 20, 1913, by Secretary of the Interior Fisher: II. CLASSIFICATION. 1. Land shall be classified as coal land if it contains coal having— (a) A heat value of not less than 8,000 B. t. u. on an air-dried, unwashed or washed, unweathered mine sample. (6) A thickness of or equivalent to 14 inches for coals having a heat value of 12,000 B. t. u. or more, increasing 1 inch for a de- crease from 12,000 to 11,000 B. t. u., 1 inch for a decrease from 11,000 to 10,500 B. t. u., 1 ineh for each decrease of 250 B. t. u. from 10,500 to 10,000, and 1 inch for each decrease of 100 B. t. u. below 10,000. (c) A depth below the surface for a bed of coal 6 feet or more thick of not more than 100 feet for each 300 B. t. u. or major fraction thereof, and for a bed of minimum thickness for that coal a depth of not more than 500 feet, and for beds of any thick- ness between the minimum and 6 feet a depth directly propor- tional to that thickness within these limits, provided that, if the coal lies below the depth limit but within a horizontal distance from the surface not exceeding 10 times the-depth limit, or if its horizontal distance from the foot of a possible shaft (not deeper than the depth limit) plus 7.5 times the depth of such shaft does not exceed 10 times the depth limit, the land shall be classified as coal land; provided, further, that the depth limit shall be com- puted for each individual bed, except that where two or more beds occur in such relations that they may be mined from the same opening the depth limit may be determined on the group as a unit, being fixed at the center of weight of the group, no coal that is below the depth limit thus determined to be considered. 2. Classification shall be made by quarter-quarter sections or surveyed lots, except that for good reason classification may be made by 23-acre tracts or multiples thereof described as minor subdivisions of quarter-quarter sections or rectangular lotted tracts. II. VALUATION. 3. For purposes of valuation the price per ton for a noncoking, nonanthracite coal 6 to 10 feet thick shall be one-tenth of a cent for each 1,250 B. t. u.: (a) Provided that the price per ton may be increased by not more than 100 per cent if the coal is coking, smokeless, or anthracitie or has other enhancing qualities; or it may be decreased for high sulphur or ash, friability, or nonstocking or other qualities that . reduce the value; and ; (6) Provided, further, that if the coal in one bed is over 10 feet thick the price on each foot above 10 feet shall be reduced 1 per cent for each such foot (thus the reduction will be 1 per cent on the eleventh foot, 2 per cent on the twelfth foot, and so on); or if the coal is less than 6 feet thick the price shall be reduced by CLASSIFICATION OF MINERAL LANDS. 97 multiplying the normal value by —, where ¢ equals thickness in feet; and (c) Provided that where the thickness of any bed varies irregu- larly its computed thickness (CT) over any area shall be equal to the average of the measurements (AM) less the sum of the differences between each measurement and the average of the measurements (SD) divided by the sum of the measure- ments (S): _SD Ss 4. The value of any acre within 15 miles of a railroad in operation shall be determined at the rate per ton prescribed above on an estimated recoverable tonnage of 1,000 tons to the acre-foot: CT peuoded that if the coal is in several beds having an aggregate thickness of more than 10 feet if beds less than 6 feet thick are considered at the reduced thickness as prescribed above, the value due to each foot above 10 feet shall be reduced 1 per cent for each such foot (as in computing the price per ton on a single thick bed) up to a thickness of 80 feet, above which any addi- tional thickness shall be valued at 380 per cent of the normal value. 5. This price shall be decreased one-half if the land is more than 15 miles from a railroad in operation, or if it is within that limit but inaccessible owing to topographic conditions; but no land shall be valued at less than the legal minimum price, nor shall the price of any land exceed $300 an acre except in districts which contain large coal mines and where the character and extent of the coal are well known. 6. Within the above restrictions a graded allowance shall be made for increas- ing depth, and allowance may be made for any special conditions enhancing or diminishing the value of the land for coal mining. 7. If only a part of a smallest legal subdivision is underlain by coal the price per acre shall be fixed by dividing the total estimated coal values by the number of acres in the subdivision, but this price shall not be less than the minimum provided by law. 8. When lands which were at the time of classification more than 15 miles from a railroad are brought within the 15-mile limit by the beginning of opera- tion of a new road, all values given in the original classification shall be doubled by the register and receiver. 9. Review of classification or valuation may be had only on application there- for to the Secretary, accompanied by a clear and specific statement of conditions not existing or not known to exist at the time of examination. RESTORATION. After the classifications and valuations are completed the lands are restored to entry. Those that contain no coal resume the status that they had prior to the withdrawal. The coal lands, after restoration, may be acquired under the coal-land laws at the valuation prices, surface entry under the agricultural-land laws and the State selection 78894°—Bull. 587—183——7 98 CLASSIFICATION OF THE PUBLIC LANDS. acts being permitted at any time prior to their alienation under the coal-land laws. A typical order of restoration is given below. DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY, Washington, February 12, 1913. The honorable the SECRETARY OF THE INTERIOR. Sir: The classification of the lands listed below, which are included in an existing withdrawal, has been completed and reported to the Land Office, and I therefore recommend the submission to the President, for appropriate action, of the following order of restoration, involving 264,009 acres, all noncoal. These lands are not included in petroleum or phosphate reserves or in ——- forests, but part are within a power-site reserve. Very respectfully, cao Gis SMITH, Director. FEBRUARY 18, 1913: Respectfully referred to the President with favorable recommendation. WALTER L. FISHER, Secretary. ORDER OF RESTORATION. Coal-land restoration—Idaho No. -10. So much of the order of withdrawal made heretofore for the purpose of coal- land classification, namely, Idaho No. 1, as affects the lands hereinafter described is hereby revoked for the reason that the Director of the Geological Survey has classified these lands. This revocation does not affect withdrawals or reserva- tions other than as above set forth. Boise meridian. T. 385 N., R. 1 E., all of township. [Here follows the remainder of the land description. ] Won. H. Tart, President. FEBRUABY 18, 1913. FIELD WORK ON COAL LANDS... GENERAL NATURE OCF THE WORK. The second general step in the process of classification is to obtain in the field the information there available that is necessary for the classification. Field work that is done expressly for the classifica- tion of coal land involves all research that is made in general geologic field work but gives special weight to certain factors. The informa- tion needed for classifying coal land relates to (1) location, (2) stratigraphy, (3) horizontal extent and thickness of coal beds, (4) vertical position, and (5) quality of the coal. These may be taken up in turn. CLASSIFICATION OF MINERAL LANDS. 99 LOCATION. In work done for classification all the points or features concern- ing which information is obtained in the field must be accurately located with reference to the land lines, for if locations are not exactly specified the information is of little value. For example, a geologist may study an outcrop of a 30-foot bed of coal, measure its sections, photograph it, and sample and analyze the coal to determine its quality or test it in any other way, but if, when he has done all these things, he can not tell whether the outcrop is in sec. 31 or sec. 32 of a given township, the information he has gathered is entirely valueless for purposes of classification. It is therefore necessary that all the features to which his information relates be accurately located on his field maps, with special reference to township and range lines, section lines, and quarter-section lines, and even accu- rately within the 40-acre tracts, as it is desirable to know exactly how many acres of the forty are underlain by coal in order to determine the value of that particular forty. The methods of survey by which the geology is tied as accurately as possible to the public- land net have been described in a preceding chapter. STRATIGRAPHY. The first purpose of gaining a thorough knowledge of the stratig- raphy is to be able to recognize groups of rocks that are coal bear- ing elsewhere or to recognize other rocks that the wide experience and knowledge now available concerning the geology of the Western States have shown not to be coal bearing. The second purpose is to determine, from such data as may be obtained on the surface, the “lay” or structure of the coal-bearing formation and the groups of coal beds it contains. Just as in the Eastern States it has been found that workable coal beds are confined to a particular part of one large group of rocks, which has long been designated the “coal measures,” so in the West it has been found that workable coal beds are confined to relatively few groups of rocks, which are separated usually by great thicknesses of other rocks that are nowhere known to contain workable coal beds. As the sedimentary rocks of the West consist mainly of sandstones, shales, and limestones, those of like lithologic character being simi- lar to one another in general appearance, the particular sand- stones and shales with which the coal beds are associated can as a rule be distinguished only by means of the fossil plants or animals that are associated with them. Thus it has been found necessary to employ the services of several experienced paleontolo- gists to examine the fossils associated with the rocks and from these fossils to determine the age of coal-bearing formations. 100 CLASSIFICATION OF THE PUBLIC LANDS. The first step of the geologist who has been sent into a field or area that is known or has been reported to contain workable coals is usually to determine what groups of rocks occur in that region and then, knowing the groups of rocks that contain workable coal beds in other places, to concentrate his attention on those groups, hunting for coals in them. Having found the coals his next work is to determine the number of groups of coals, as the same territory may contain two or three or even more coal-bearing formations, though usually they occur in different parts of the same field. His next step is to examine the several coal-bearing formations in order to determine, if possible, the number of coal beds in each. This work naturally leads to the determination of the areal extent and thickness of the beds. EXTENT: AND THICKNESS OF COAL BEDS. Coal is a rock that has been formed from vegetal matter. The vegetation may have grown where the coal bed is now found, much as it grows in the great peat bogs of Europe or some of the large swamp areas of this country, or it may have been washed or drifted from the place where it grew to the place where it now occurs as coal. In changing from a mass of decaying vegetal matter to a bed of coal its volume has decreased and its weight per cubic foot has greatly increased. It has also lost many of the elements of the* plants, es- pecially the moisture they contained, and if during its formation the coal bed was inundated by muddy waters its vegetal matter may have been overlain or intermingled with sand or mud. This material may have been added in small quantities at frequent inter- vals, simply rendering the coal “ dirty,” or it may have come in at long intervals and then in large quantity so as to form a blanket of mud or sand, which, being covered by renewed accumulations of vegetal matter, becomes a parting of clay or sandstone in the coal bed. In a few places a single coal bed has been deposited in a formation, and thousands of feet of other rocks have been laid down beneath and above it, no other coals having been formed. More fre- quently, however, where coal-forming conditions have existed they seem to have recurred in such a way that a succession or series of coal beds are laid down in the same area. In one region most of the coals in a group deposited in that way may be thicker in the same general area, and all the beds may tend to thin away from that area. In another region one bed of a group may be thicker in one locality and a higher bed of the same group may be thicker in another locality. Coal beds vary greatly in extent, ranging from pothole fillings having about the shape though not the size of a kettle to flat- lying beds thousands of square miles in extent. In Missouri a num- ber of coal beds have a thickness in places of 90 feet or more and CLASSIFICATION OF MINERAL LANDS. 101 an areal extent of only a few hundred feet or less, being simply fillings of deep holes in the rock, similar in shape to the “ pot- holes” that are so abundant around some waterfalls. In other places, as in the Sharon field of Ohio, the coal bed has the shape of a valley, with branches where side streams have come in, and a single mine may follow one of these valleys for some distance, the coal being confined to a width of perhaps a few hundred yards but extending indefinitely up and down the valley, which in some places winds tortuously. In still other places, as in the Block coal field of Indiana, the coal occurs in a succession of shallow basins, the beds having a thickness of 3 to 5 feet in each basin and thinning out to a few inches between the basins. The bottoms of the basins lie 20 to 30 feet below their rims. Some of these basins are so small and so close together. that the coal from»several of them is extracted by a single mine, the entries being cut through the rock from the lower level of one basin to the lower level of the next basin. Other basins have a length of 2 or 3 miles in a northwest- southeast direction and a width of one-half mile or more. Some of the individual beds can be traced from basin to basin and clearly recognized by peculiarities in the coal. In other fields the coal ap- pears to have been deposited unevenly in little depressions that are scattered irregularly over a large territory and lie at various levels, so that it is not possible to trace a bed from: one point to another, and each little basin must be considered as a unit. From these types of irregular and narrowly limited coal beds every gradation may be found to some of the relatively even and continuous beds of the West, the extensive beds of the central interior coal fields, or the Pittsburgh and other beds of the East, which have an outcrop line hundreds or even thousands of miles in extent and were laid down in _ amore or less continuous sheet, many of them covering thousands of square miles. Thus the Pittsburgh bed has a known extent of over 6.000 square miles and is found in isolated areas beyond the limits of the main bed. Other Appalachian coal beds are of much greater extent, some of them, as the Lower Kittanning, having many times the areal extent of the Pittsburgh bed, though not its regularity. Certain coal beds in the Illinois fields have been traced without question as to their identification over a large part of that State, through a portion of western, Kentucky, and through the entire length of the Indiana coal field. It is believed that many of the coal beds of the Western States are also traceable over large areas. Most of these widely extended coal beds have certain slight but definite features or peculiarities or are associated with other rocks of dis- tinctive character, so that it is possible to recognize them at any point. The peculiarity of a bed may consist of some particular type of parting or arrangement of partings which may hold for long dis- 102 CLASSIFICATION OF THE PUBLIC LANDS. tances, or it may consist of the presence just above or below the bed of a stratum that has easily recognizable characteristics. In order to trace and identify some coal beds it is necessary to study their rela- tions to one another. One of the main reasons for studying the stratigraphy is to identify if possible at the outset the group of coals studied, and in this work note should be taken of the determinations reached by the wide study of the same formations in previous seasons. For example, in the great coal field that covers much of western North Dakota and part of South Dakota, all of southeastern Montana and the great Powder River field of Wyoming, there are two coal- ‘bearing formations—the Fort Union above, named from its early recognition at Fort Union in North Dakota, and the Lance forma- tion below, named from the occurrence of those rocks on Lance Creek in Wyoming. The Fort Union coals are as a rule persistent; they have local thicknesses of 10 to 30 feet or more, and some of them can be traced for hundreds of miles along their outcrop, and individual beds can be recognized from point to point. On the other hand, the Lance coals occur as a rule in small lenses, most of them a fraction of a mile or a very few miles in extent. The coal in these lenses ordinarily is but little above the minimum workable limit and thins rapidly to nonworkable thickness in all directions. If the geologist knows that the coals in any particular area are in the Fort Union or Lance formation he knows what to expect concerning them, for if he finds that they are of Lance age and he is studying at the moment the coal at a point where it is workable, he is careful to trace it if possible in order to see how far it may extend before it becomes unworkable, so as to determine as closely as practicable the extent of that particular lens. If, on the other hand, he knows that the coal before him is of Fort Union age he attempts to de- termine, if possible, what particular coal bed in the Fort Union it is, and, assuming that he will find that same bed in a large part of the country ahead of him and that he will judge of its thickness by com- bining a great number of measurements made over a large territory, he does not with the same attention attempt to discover whether the ~ coal pinches out a short distance on either side of the point where he is standing. In all of this work it is, of course, not safe to assume too much, for toward the south end of the Powder River field the beds of coal in the Lance formation increase in exterit and thickness, so that they more nearly resemble those of the Fort Union formation, farther north. It is not advisable to assume absolutely that, because in some area already examined a coal bed is very extensive and keeps the same thickness with great regularity, it will continue to be extensive and regular in territory that may be studied later. For example, the Pittsburgh bed, which maintains a very uniform thickness over a CLASSIFICATION OF MINERAL LANDS. 7 103 large area in western Pennsylvania, becomes very irregular in south- ern Ohio, so much so that it has been wrongly identified, and it is only within a few years that the bed there identified as the Pitts- burgh has been shown to be another coal higher in the series. Like- wise, in the Illinois-Indiana field coal V, which is probably the most persistent bed in that field and can be traced along its outcrép for thousands of miles with great regularity, pinches out in parts of Greene County, Ind., close to other localities where it shows its greatest thickness; and, again, in Warrick County it loses its usual characteristic roof and is split into two distinct beds. In the same way many of the coals in the West that on casual scrutiny appear to be persistent prove, when studied in detail, especially in connection with mining operations or where close prospecting has been done with a drill, to vary considerably both in thickness and in distance apart. For example, at Castlegate, Utah, four beds are at one point separated by 50 feet, 20 feet, and 14 feet of strata, whereas a short distance away these intervening rocks pinch out and the four beds, which separately are on the average only about 3 feet thick, come together to make a single bed 12 feet thick. Drilling in that field has shown that all the beds tend to be very irregular, splitting and combining again and changing in thickness, so that in tracing them from drilling to drilling it may be found that though each core shows certain workable beds, yet a bed that is thick at one point is thin at the next. Detailed work in many of the eastern fields where extensive mining operations have afforded minute data in regard to the coal, or where thousands of dollars have been expended in crilling, has shown that even the most persistent of the beds are sub- ject to variations, so that a bed which can be traced from one mine to another over a whole county and which- may show a variation of only a few inches from mine to mine may suddenly, in mining parlance, “ go to pieces.” It is therefore the special work of the field geologist not only to locate the coal on the ground but to make as detailed a study as possible of its thickness and extent in order to learn just how far it maintains a workable thickness, how per- sistently it maintains a given thickness,and whether it is likely to vary greatly from point to point and also to determine, so far as he can, any or all of its features. Space does not permit the detailed de- scription here of all the possible irregularities that may occur in a coal bed, for which the field geologist must be on the lookout. In some fields the coal beds are exposed in cliffs or steep slopes in such a way that the coal may be seen almost continuously for many miles. In such places the geologist takes the opportunity to make a careful study of the regularity or irregularity of the coal beds with reference both to their thickness and to the variability or regularity 104 CLASSIFICATION OF THE PUBLIC LANDS. in thickness and in character of the intervening rocks and of the spaces between the beds. In regions in which the beds are not well exposed it may be possible, from a knowledge of the position of a bed with reference to other rocks which show on the surface, to determine exactly the position of the particular coal under considera- tion and, by means of a very small amount of digging, to expose the bed so that its thickness and partings can be measured. In some coal fields hundreds of such openings have been made in the study of the bed. In other fields the beds occur in rocks that weather down to soils rapidly, and it may be only where a coal bed crosses a stream or is otherwise exposed that it can be located or seen. It may be difficult to trace such a bed from point to point, and in some places where exposures are several miles apart it may be difficult or impos- sible to determine exactly its position. In other places beds may be traced readily, but the fact that they have been burned continuously along their outcrops makes it difficult to get accurate information concerning their character and thickness. It is of course possible to map the position of the coal bed in such places and it is then neces- sary, from such information as can be obtained concerning the thick- ness and character of the coal, to infer its character at points between these places. It is especially in such areas that a general knowledge of the “habits” of the bed or group of beds assists in their classifica- tion, for if it is known that a particular bed, whose burned outcrop has been traced with detailed measurements perhaps at only one or two places in a township, occurs at a certain horizon in a certain formation, it is possible to surmise whether it is regular or irregu- lar in the broad area between these exposures, where no information on the bed itself can be obtained. Again, it may be possible, by mak- ing a careful study of a coal in a mining region, to apply the infor- mation to a wide area where but scanty information on the coal itself can be obtained. Wherever the coal is exposed the field man makes careful examination and measurement of every possible sec- tion, measuring down to the fraction of an inch, even though, where the bed is irregular, it is recognized that another measurement made a short distance away may be quite different. Where a bed is irregu- lar special effort is made to obtain as many measurements as possible, in order to obtain average figures for use in the classification and valuation of the land underlain by that bed. In some places where the data are very meager, as in regions where the rocks crum- ble to soil and the land is largely meadow land, considerable time has been given to making openings on the coal because of the neces- sity of having actual information and measurements as a basis for classification. GLASSIFICATION OF MINERAL LANDS. 105 ATTITUDE AND DEPTH OF THE COAL. As already stated, the coal throughout wide areas lies entirely below the level of drainage—in places hundreds or even thousands of feet below—and the outcrops of the particular coal beds on which land is classified as coal land may be scores of miles away. It there- fore becomes necessary for the field man to determine as accurately as possible not only the position of the coal outcrop with reference to the land lines and the thickness of the coal as exposed along the outcrop or the extent of the lenses, but also the depth of the bed beneath the surface and its attitude as it dips into the basin. He does this, first, by studying the inclination of the coal beds where they dip into the ground and, next, by studying the inclination and thickness of the other rocks that overlie them. As coal beds lie more or less nearly parallel with layers of sandstone, shale, and limestone, one of his duties is to determine how nearly the coal beds are parallel with these other rock layers. If he finds by observation at many points that there is very little variation in the interval, say 300 feet, between a limestone bed above and the coal bed that he is studying, he may assume that the dip of that limestone bed measured possibly at a point a mile back from the outcrop of the coal indi- cates the dip of the coal beneath that point at a level 300 feet below the surface. If, again, he finds that some other rock bed a thousand feet above the coal bed is parallel to it, he may assume that a measure- ment of the dip of that bed taken 5 or 10 miles back from the coal outcrop may indicate rather closely the dip of the coal bed. itself 1,000 feet below. Hence the field geologist must not only study the details of the coal bed along its outcrop, but must also study the geology of the area back of that outcrop, especially with reference to the dip of the rocks. If, as sometimes happens, he finds that the space between a coal bed and the overlying rocks is variable, he can not compute the depth of the coal bed so closely. In some places all the rocks associated with certain coal beds, having the same great folds and basins, have been overspread by a blanket of other rocks that do not have the same structure. Such a blanket may completely hide not only the coal-bearing formation but the other formations that are associated with it and that have been folded in the same way. In such places it is only possible to infer from broad general knowledge of the field how deep the coals may lie below the surface. QUALITY OF THE COAL. The character and quality of a coal can be determined in part by a simple examination of the coal bed. Thus it is possible in most examinations to determine whether a coal is a lignite, a subbitumi- 106 CLASSIFICATION OF THE PUBLIC LANDS. nous coal, a bituminous, a cannel, or an anthracite coal. It may also be possible to estimate rather closely whether or not a coal contains a large amount of ash. Where small mines or prospects have been opened it may be possible, by studying the coal on the dump, to determine whether the coal can be shipped or stocked, or the extent to which it tends to crumble under the action of the atmosphere. The final tests, however, are the chemical test, consisting of an analysis of the coal, which shows fully its percentage of the various heat-giving elements and of the ash and other elements that do not vield heat but detract from its value, and the test of its heat-giving value in the calorimeter. Experience has shown that coal of certain kinds—especially low-grade coal—changes in chemical composition very rapidly when exposed to the weather, so that in getting samples for analysis it has been found necessary, in order that the samples may be fairly compared and may form the basis of a uniform system of classification and valuation, that they be taken with great care in a uniform manner and that. the treatment of each sample from the time it is taken until it is analyzed shall follow certain standards. To this end certain regulations have been prepared in regard to the method of obtaining coal samples for analysis and are consistently enforced. These regulations in brief are as follows: 1. Select a fresh face of unweathered coal at the point where the sample is to be obtained and clean it of all powder stains and other impurities. 2. Spread a piece of oilcloth or rubber cloth on the floor so as to catch the particles of coal as they are cut and to keep out impurities and excessive mois- ture where the floor is wet. Such a cloth should be about 14 by 2 yards in size and should be so spread as to catch all the material composing the sample. 38. Cut a channel perpendicularly across the face of the coal bed from roof to floor, with the exceptions noted in paragraph 4, of such size as to yield at least 6 pounds of coal per foot of thickness of coal bed; that is, 6 pounds for a bed 1 foot thick, 12 pounds for a bed 2 feet thick, 24 pounds for a bed 4 feet thick, ete. 4. All material encountered in such a cut should be included in the sample, except partings or binders more than three-eighths inch in thickness and lenses or concretions of “sulphur” or other impurities greater than 2 imches in maximum diameter and one-half inch in thickness. 5. If the sample is wet, it should be taken out of the mine and dried until all sensible moisture has been driven off. 6. If the coal is not visibly moist, it should be pulverized and quartered down inside the mine to avoid changes in moisture, which take place rapidly when fine coal is exposed to different atmospheric conditions. The coal should be pul- yerized until it will pass through a sieve with one-half inch mesh, and then, after thorough mixing, it should be divided into quarters and opposite quarters re- jected. The operation of mixing and quartering should be repeated until a sample of the desired size is obtained. When the work has been properly done a quart sample is sufficient to send for chemical analysis. This sample should be sealed in either a glass jar or a screw-top can with adhesive tape over the joint and sent to the chemical laboratory for analysis. CLASSIFICATION OF MINERAL LANDS. 107 Since the value of the land varies with the quality of the coal as determined by the chemist, his methods are briefly described here.t Immediately after the sample is received at the laboratory it is weighed and placed in a shallow tin pan in a large drying oven, in which a temperature of 30° to 35° C. is maintained. The sample remains exposed to currents of warm air in the oven until the loss between two successive weighings made six to eight hours apart does not vary more than 0.2 per cent. The loss of weight in the oven is called air-drying loss. After being air dried the sample is crushed to a fine powder and thoroughly mixed. To determine the amount of moisture remaining in the coal after air drying, a 1-gram sample is heated for an hour at 105° C. and then cooled in a desiccator over sulphuric acid. The ‘moisture in the sample is thus driven off, hence the percentage of loss represents the percentage of moisture in the coal. The remain- ing part of the sample is next used to determine the amount of ash in the coal. This determination is made by slowly heating the sample in a muffle furnace until all of the combustible matter is burned off. The remainder is ash. The volatile matter is deter- mined from a fresh 1-gram sample in a 30-gram platinum crucible, with a close-fitting cover, heated for seven minutes over a Bunsen flame 20 centimeters high. The loss in weight minus the moisture at 105° C. is the weight of the volatile combustible matter. The sulphur is determined on a separate example by what is known as the Eschka method. The percentage of fixed carbon given in the analysis is the difference between 100 per cent and the sum of moisture, volatile combustible matter, and ash. The calorific value of a coal, or the amount of heat that can be obtained from it, is the most important factor in classification and valuation. The calorific value of coal is determined with a bomb calorimeter. The following is a brief description of the details of operation: A 1-gram sample of coal (60-mesh) in a platinum tray is placed in the bomb and the lid is screwed down tightly against a lead gasket. Oxygen is forced into the bomb until the pressure is 18 to 20 atmospheres. The bomb, filled with oxygen, is placed in a brass bucket containing distilled water, the bucket having been previously placed in an insulated jacket. The coal is ignited by electric current and is burned at once. The heat of combustion is transmitted through the walls of the bomb and is manifested in a rise in the temperature of the water. This rise in temperature is measured by a very delicate thermometer. The 1The methods of analyzing coal and coke are fully described in Technical Paper No. 8, Bureau of Mines, by Frederick M. Stanton and Arno C. Fieldner. The method outlined here is summarized from that paper. 108 CLASSIFICATION OF THE PUBLIC LANDS. quantity of heat given off by the burning of the coal is determined by multiplying the product of the weights of the metal and water in the apparatus and their respective specific heats by the rise in temperature. The result thus obtained is calculated into terms of calories and British thermal units. PREPARATION OF JMATERIAL. The preparation of material by the field man, so that it may be considered to the best advantage in the work of classification and valuation, has already been considered in the chapter entitled “ Prepa- ration of data for classification,” immediately preceding the discus- sion of the classification of coal lands. PROCEDURE IN CLASSIFICATION AND VALUATION. In the actual work of classification of coal lands each area under consideration must be treated individually, yet in general a definite line of procedure is followed. The first step is to assemble all the available data, including not only the maps and reports of the geologists who may have made a special examination of the field, but the reports of any special agents of the Land Office who have been in that field, as well as all reports of geologists who may have visited the field at some earlier time (prob- ably for some other purpose) and all other available information concerning the land or the coal it may contain. The land-classifica- tion board has a system of graphic records which show at once the existence of any reports on the field and give references to them, so that when the case is taken up all the data available are at hand. As a matter of fact the field man will usually have familiarized himself with all these earlier data and will be prepared to present them as may be necessary. The second step is to scrutinize carefully all these data, and by their aid to take the action or to obtain the information listed under the following heads: 1. The number, names, character, and other features of the coal- bearing formations are alien ne As most of these formations extend over large areas, some of them crossing several States, a gen- eral knowledge of the formations at once suggests the probable con-. ditions to be found in the field studied, and that general knowledge may strongly affect the action to be taken in classification and valuation. 2. The number of coal oo or groups of horizons is ascertained. 3. The thickness of each coal bed over the field is determined, if it can be traced. If each bed can not be traced the group of coals CLASSIFICATION OF MINERAL LANDS. *109 is studied as a whole to determine from point to point the number of beds and their aggregate thickness and value. 4, The basing value per ton of the coal is computed by comparing its analyses and its obvious character with the standard scale. An average B. t. u. value having been fixed for the coals of the field or for the different groups of coals, the other qualities of the coal— such as its adaptability to coking or to stocking—are studied to de- termine whether they enhance that value or detract from it, and the price is raised or lowered accordingly. 5. If the field is small and the data are scattered the field may be studied as a unit. If the data are abundant in any township the coals in that township are studied by themselves, and, exceptionally, the variation in thickness may make it necessary to divide a town- _ ship into belts or areas, in each of which a basing value of the groups is determined. 6. All sections of the coal are examined, and if the coal beds are split the equivalent thickness of a solid bed is computed and a memo- randum of the results is placed beside the drawn section. Then further reduction is made for the reduced value of the bed, if it is less than 6 or more than 10 feet thick. If a bed is variable in thick- ness but varies so regularly that lines of equal thickness can be drawn on a map of the field these lines are so redrawn as to indicate the reduced thickness determined by allowance for their reduced value if the thickness is less than 6 or more than 10 feet. If the beds are of irregular thickness the average of the measurements taken is ob- tained, and by the use of the “ modulus of irregularity ” a computed average thickness is obtained for use in valuation. 7. The outcrops of the coals are examined to determine which are workable coals and especially to make note of the outcrop of the lowest bed or the bed covering the largest area. Where the coal lies in one or more lenses a computation of its gradation in thickness is made between points at one of which the coal is below the minimum thickness and at the other is above, to determine the position of the minimum. The limits of workable coal having been determined for certain points, the limits of the lenses of the coal are drawn on the maps. For isolated measurements at points where the bed is above the minimum limit the extent and character of the several lenses measured are determined, special formulas being applied where possible. 8. If the coal passes below the depth limit of workable coal the position of that limit is determined and indicated on the map. 9. The limit of workable coal having now been determined, a line is drawn on a plat along the 40-acre lines, or, where necessary, along the 10, 5, or 24 acre lines in the forty, to separate the area that con- 110 - CLASSIFICATION OF THE PUBLIC LANDS. tains workable coal from the area that does not contain workable coal. The latter area is then plainly marked “noncoal,” and if the jand is only to be classified and not valued a copy of the plat is made on a blank township sheet to show accurately the coal land and the noncoal land. This copy, after checking and proper designation, is dated and signed by the members of the coal section of the board. Its later history is the same as if valuation had been made. 10. The tract or township may now be valued. The particular steps at this point may vary greatly, depending on the complications involved in the valuation. It may be that the coals are of a grade so low that, like the low-grade lignites, regardless of their thickness, they will be valued only at the minimum. Or it may be that the tract contains only one thin bed that lies flat and at slight depth, so that the land may be valued at the minimum or perhaps at a uni- form price. From these simple conditions there will be conditions grading in complexity all the way to those found in such fields as, for example, the Rock Springs field of Wyoming, where there are three groups of beds of coal of different age, character, and quality, each group containing from six to eighteen coal beds, and where each coal bed has been accurately traced by means of hundreds of measure- ments made on the coal in each township, both along the outcrop and in mines and drillings. Owing to differences in quality and thickness coals have different depth limits. They may also vary in dip and may be locally broken by faulting or by igneous intrusions. The value of the land that is involved in these complications is computed by using printed blanks that contain columns arranged to show not only the observed data on each bed in each 40-acre tract, but also the com- puted values of each bed, ending with the computed value of the 40 acres. This completed blank becomes part of the permanent record, so that, if additional data are obtained or if for any reason the valu- ation should be reviewed, it shows not only the field data but the steps that have led to the final result. As values are determined they are recorded on a blank township sheet and if the data are abundant and complicated the coal boundaries may be drawn on transparent over- sheets, on which the computed valuation prices are placed. This sheet is properly labeled, dated, and signed by the members of the coal section. 11. As the land in a township is classified and valued memoranda are prepared to show the basis for any criteria used, and all these memoranda, with blank forms showing the computations and allow- ances, are retained as “ minutes” and, when reviewed and signed. by the members of the coal section, form a part of the permanent record. 4 a 7 : 2 ‘ is , . - : SPORT Pe eee OIL AND GAS LANDS. Lt PROGRESS IN CLASSIFICATION AND VALUATION. The following statement shows the status of the work of classi- fication on January 1, 1913: Progress of coal-land classification to January 1, 1913. Swed withdrawals... acres__ 128, 147,312 Area classified and valued as coal land_______ do__... , 16, 483, 817 Area classified as coal land, price not fixed___do____ 841, 706 Area classified as noncoal land______________ do____ 42, 244, 682 Restored without classification______________ doe 2, 617, 395 Metotal restorations: -... do-i > “G2: 937.600 Total withdrawals less total restorations (total out- Srandin= withdrawals). acres__ 65, 909, 712 Value of coal land at classified price_______________ $702, 157, 268 este Tie IMATITIN) TICE 28 | 8 $279, 122, 661 OIL AND GAS LANDS. OCCURRENCE OF OIL AND GAS. To the minds of many people who find little difficulty in compre- hending a classification of lands containing deposits of coal or phos- phate the possibility of applying a similar classification to lands containing oil and gas, especially in advance of actual drilling, appears uncertain, to say the least, and, according to the nature and experience of the individual critic, such a classification is looked upon either as a more or less scientific guess or as evidence of the possession of supernatural powers by the classifier. The classification of oil and gas lands, however, calls for the use of no mysterious or haphazard methods but is based on detailed field examinations, followed by careful consideration of all the available facts, geologic and economic, in their relation to one another and to the known principles of the occurrence of oil, which have been proved again and again in the development of oil fields throughout the world. Although the ulti- mate test of the presence of oil in commercial quantities is made with the drill, it is nevertheless a fact that the intelligent application of the principles of oil accumulation to the geologic facts observed will indicate at least the areas where no oil will be found and will go far toward delimiting the areas where production is reasonably certain. _ To the classifier of oil lands, as to the oil-well driller, the theories proposed to account for the origin of oil and gas are of only inci- dental interest; the problem of prime importance to him comprises the assignment of proper values to the many factors which influence accumulation and the determination therefrom of the present posi- tion and extent of the deposits. 112 CLASSIFICATION OF THE PUBLIC LANDS. Oil and gas are composed for the most part of carbon and hydro- gen, but they vary greatly in the proportions of these elements and in the way in which they are combined. The petroleum oils range from. low-grade heavy oils containing much asphalt to high-grade light oils which contain a large percentage of paraffin and volatile constituents and little or no asphalt. The heaviest oil is chiefly valu- able as fuel, for which it is used in its crude state. Progressively lighter oils are used less and less for fuel and more and more for the other products that are obtained from them. There is a general opinion that weight for weight the fuel value of light and heavy oils is about equal, but because of the value of the distillates from the lighter oils it may be stated in general that the lighter the oil the greater its value. In classifying lands as to their probable content of oil and gas it must be borne in mind that oil and gas are mobile substances and that, owing to their mobility and to the resulting increased impor- tance of gravitation, temperature, hydrostatic pressure, and capil- larity, it is necessary to make certain variations from the type of procedure employed in classifying lands containing coal, phosphate, or other stable minerals. The mobility of oil and gas has, in many regions, permitted their migration through varying thicknesses of pervious strata to their present places of accumulation, so that the problem is not to discover where the hydrocarbons originated but rather where they have accumulated. The present position of these accumulations depends mainly on the character of the strata, the attitude of the strata (commonly spoken of as the rock structure), the presence or absence of water, and the character and specific gravity of the oil. The fluid hydrocarbons do not, as is supposed by some, occupy underground lakes or reser- voirs surrounded by walls of rock. Instead they saturate porous rocks in places where the geologic structure, the conditions with regard to underground water, and the succession of strata are such that the accumulations are sealed by relatively impervious beds. Thus, although the accumulations of oil or gas are called “ pools,” they are not to be confused with such, pools as are formed by the collection of liquids upon the surface of the ground. The porous stratum in which the hydrocarbon collects is often spoken of as an oil or gas “sand,” although it may in reality be sandstone, gravel, limestone, or a zone of fractured rock. Into this “sand” the hydro- carbon comes from’ one or another source, but if there is to be an accumulation of importance the migration of the oil or gas along this pervious bed must be stopped by a change in dip or by some other obstacle to continued progress, and, in addition, the reservoir thus formed must be sealed by strata that are relatively impervious, OIL AND GAS LANDS. 113 such as compact shales, clays, or fine-grained sandy beds saturated with water. The accumulations within the United States may be divided roughly into three classes, as indicated below. 1. Those occurring in strata of sandstone or limestone bounded above and below by rocks comparatively impervious to oil. The sandstone or limestone may be of broad or of very narrow extent, in some places comprising merely small lenses of porous material embedded in relatively impervious rocks, in others underlying hun- dreds of square miles of territory in comparatively regular beds. To this class belong the greater number of oil accumulations of this country. 2. Those occurring in porous strata, apparently lenticular, asso- ciated with the “salt domes” of the Gulf Coastal Plain. 3. Those occurring in fissures in shale, as in the Florence field of Colorado. The fracturing of other rocks, such~as limestone and sandstone, affords favorable conditions for the accumulation of oil; but sandstone and, under certain conditions, limestone are capable of storing oil without fracturing, the fracturing merely increasing their capacity. A fine-grained shale, on the contrary, although capable of containing oil, does not permit its migration through the rock mass with sufficient rapidity for collection in wells unless the shale is broken by fissures, which serve as channels or reservoirs for the slowly migrating oil. It may be stated as a fundamental principle that important accu- mulations of petroleum and natural gas are to be found only in stratified or sedimentary rocks. Regions in which the strata have been greatly disturbed or altered by intrusions of igneous rock are, as a rule, unfavorable to the accumulation of petroleum, because the attendant heat and fracturing would as a rule have had disastrous effects on volatile substances of this character. An interesting appar- ent excepticn has been noted in Ventura County, Cal., where oil to the extent of 5 or 6 barrels a day has been obtained from wells drilled in close-textured crystalline schist. Although the schist is underlain by granite, it is overlain at a distance of only a few hundred feet from the wells by Tertiary rocks which in the same general region are petroleum bearing. These relations suggest that the presence of the oil in the schist is due to infiltration from the Tertiary sediments through fractured zones rather than to origin in the sediments that were metamorphosed to form the schist. In general, then, oil is found in sedimentary strata of greater or less extent and regularity. These strata were originally deposited by water in the ocean, in fresh-water lakes, or on great deltas prac- tically at sea level. The beds were therefore horizontal, or nearly 78894°—Bull. 587—18——_8 114 CLASSIFICATION OF THE PUBLIC LANDS. horizontal, as first laid down, and where a series of beds was de- posited one above another, there being no earth movement during the deposition, the several beds were parallel. After the beds of sand, mud, and marl were deposited and hardened into the resulting sandstone, shale, and limestone, they were in certain areas bent by earth movements into folds of various shapes, and it is about these folds that the accumulations of oil are found. The attitude in which the rocks lie, the shape of the folds, and the presence of faults or breaks in the strata constitute the rock structure. In any consideration of the factors which control the accumula- tion of oil or gas the importance of the part played by the structure can hardly be overestimated. The fluid contents of porous beds obey the laws of gravitation and capillarity, separating and distributing themselves in the main in accordance with their specific gravities. If water, petroleum, and gas are, as is usual, present in petroliferous beds, the gas would as much as possible disengage itself from the fluid and rise to the highest point in the fold, while the water would endeavor to displace the petroleum and find a resting place as low down as possible. If the bed of rock is inclined and the water is under artesian pressure, it will be forced upward along the bed, the oil remaining above the water because of the difference in specific gravity. If the porous bed is continuous in dip to the outcrop, the gas and oil are likely to exhaust themselves at the outcrop in the form of seeps. If, however, the progress of the hydrocarbons up the dip is stopped by a fold in the bed, or by a fault which seals in- stead of opening the stratum, or by saturation of the bed with water, an accumulation takes place, the oil and gas remaining between the water down the dip and whatever has impeded their progress up the dip. This theory, which is known as the anticlinal theory, is in some form now accepted by practically all geologists, not as indicating absolutely the limitations of the occurrence of oil and gas but as ex- pressing the general relations of their occurrence to geologic struc- ture, subject to various modifying conditions. Other factors less well understood enter into the problem, such as the difference in the capil- lary attraction exerted between water and the rock particles and be- tween oil and the rock particles and the differences in friction experi- enced by the two fluids in passing through the rock. There is much to be learned concerning the whole problem, but enough is known to make the study of any oil field of economic as well as scientific value. If the rock containing the oil does not also carry water there is no force to impel the oil into the upfold or anticline. On the contrary, gravity tends to pull it downward and it collects in the adjoining downfold cr syncline. This condition is found in some of the Penn- - sylvania fields. OIL AND GAS LANDS. 115 Where the migration of oil is due to the pressure of dissolved or occluded gas in the absence of water saturation the oil will move in all directions until it is stopped by some impervious stratum, where accumulation takes place in apparent disregard of structure. The simplest structure favorable to the accumulation of oil and gas is that of a symmetrical anticline having little or no pitch of the axis and moderately dipping flanks. If the requisite condition of porous oil-bearing rock adequately sealed by impervious beds is fulfilled and the strata are impregnated with water under moderate hydrostatic pressure, the hydrocarbons will, under ideal conditions, segregate in the axis of the fold and extend down the flanks a distance dependent on the quantity present. Farther down the flanks and in the troughs of the corresponding synclines water will as a rule be found. It is evident that, other things being equal, the extent of the productive area controlled by anticlinal structure is greater where the fold is broad and the dip of the strata on the flanks relatively low than where the fold is narrow and has steep flanks, for in the former case the gathering ground for oil and gas is much greater than in the latter. From the simple symmetrical anticline there are gradations on the one hand into domes pitching away from a central point and on the other hand through unsymmetrical folds to an extreme type in which one flank is vertical or overturned. In every symmetrical fold the boundary between an oil pool lying at the top of a fold and extending part way down the sides of the fold and the water saturating the rocks farther down is an approximately horizontal line, because as long as the fold is regular the water tends to rise to the same level all along it. If, however, there are minor irregularities on the sides of the fold these have their effect on the distribution of the oil, making the margin of the pool irregular or causing small pools to collect along the slope. : Structural features of other types are under certain conditions favorable for the accumulation of petroleum and natural gas. Among these may be mentioned monoclines, which present conditions favor- able for the concentration of oil wherever there is a change in the rate of dip or an abrupt change in the strike of the rocks, shallow syn- clines where water is absent from the oil-bearing zone, and synclines where the oil and water are of nearly the same gravity. Unconformi- ties where steeply dipping petroliferous strata are overlain by rela- tively impervious horizontal or nearly horizontal beds are also favor- able. Faults are usually considered wholly unfavorable to the accu- mulation of oil and gas, and for areas where the dislocations are many and extensive this view is undoubtedly correct. However, in many places faults have quite the contrary effect. For instance, strike faults may cause a greater concentration of petroleum toward the crest of a fold, and dip faults in a series where there are many oil 116 CLASSIFICATION. OF THE PUBLIC LANDS. sands may bring about communication between the different sands and have a notable effect on local production. In a series of uni- formly dipping beds an oil sand which would normally crop out at the surface may be cut off by a strike fault and sealed beneath imper- vious beds and thus retain oil which would otherwise migrate to the surface and be dispelled. Moreover, faulting may produce fractured zones along which the oil or gas can migrate and in which it may collect. In a number of localities, as in some of the fields in Mexico, where intrusive dikes have pierced oil-bearing strata and conse- quently arrested the movement of the oil in certain directions, the petroleum has accumulated in apparent disregard of the structural features of the sedimentary series. In many fields there is little or nothing at the surface to indicate the presence of valuable hydrocarbons below, but in many other fields there is ample indication of oil at the surface. The oil-bearing stratum itself may crop out and the oil ooze from it, giving to the rock a dark, greasy appearance and the odor of petroleum, or the oil may find its way to the surface from the oil pool below through some fracture of the overlying rock. Water charged with various salts or with sulphur may rise with the oil, so that a spring is formed, the oil floating as a brown scum on the surface of the water or in smaller quantity producing the brilliant iridescent sheen character- istic of petroleum. Gas may find its way to the surface and appear in “gas springs” or under certain conditions may produce the phe- nomenon of mud volcanoes. The place at which oil has come to the surface and evaporated through long periods of time may be marked by a deposit of asphaltum. In certain localities oil-bearing shales have been burnt to a pink or deep brick-red color or altered to a hard vesicular rock resembling scoriaceous lava. This metamor- phism is due to the burning of the hydrocarbons that have impreg- nated the rock, and the presence of such rock therefore becomes an important surface indication of petroleum. The stratigraphic occurrence of hydrocarbon minerals in the United States is by no means limited; on the contrary, petroleum in the solid, liquid, or gaseous form is found in greater or less quantity throughout the range of strata from the Cambrian to the younger members of the Tertiary series. In general the commercially important accumulations of oil through- out the central and eastern portions of the United States are found in strata belonging to the Paleozoic era. In the great Appalachian field, which extends from the southern portion of New York along the western slope of the Allegheny Mountains to northern Tennessee, the accumulations of oil occur in strata ranging in age from early -Devonian to late Carboniferous. In Ohio and Indiana petroleum is derived chiefly from rocks of Ordovician age, and in Indiana mainly OIL AND GAS LANDS. 147 from Carboniferous strata. In the Mid-Continent field, which em- braces Missouri, Kansas, and Oklahoma, the petroleum has accumu- lated in rocks of the Pennsylvanian and Permian series. In the Gulf © _ field, which includes the Coastal Plain of Louisiana and Texas, the petroleum-yielding rocks are Mesozoic and Cenozoic in age, being assigned in part to Cretaceous and in part to Tertiary formations. In the Rocky Mountain fields the productive formations range in age from late Paleozoic to late Mesozoic. The Wyoming fields pre- sent perhaps the greatest range of occurrence, yielding oil from strata belonging to the Carboniferous, Triassic, Jurassic, and Cretaceous systems. The Colorado and New Mexico fields thus far developed obtain their oil from strata included entirely within the Cretaceous, and the small quantity of oil produced in Utah is derived from rocks assigned to the Carboniferous system, although indications of oil are found at certain localities in the Jurassic and Cretaceous rocks. In the Pacific coast region the important accumulations of oil are found chiefly in Cenozoic rocks, although in certain fields an out- put of local importance is obtained*»from late Mesozoic rocks. In Ventura County, Cal., the principal oil-yielding formations are classed as Tertiary and range in age from Miocene to Pliocene. Along the west side of the San Joaquin Valley the range is greater, the oil extending downward into the upper members of the Cretaceous system. In the Kern River field, on the east side of the San Joaquin Valley in Kern County, oil is obtained from rocks of late Miocene or Pliocene age. In Santa Barbara County the oil is derived chiefly from early Miocene rocks. In portions of Oregon and Washington small amounts of oil and gas have been obtained from rocks assigned to the Eocene and Miocene series. Despite this wide distribution of fluid hydrocarbons the conclusion does not necessarily follow that accumulations of asphaltum, oil, or natural gas may be found in any area of sedimentary rocks, for such accumulations take place only where all the essential conditions gov- erning origin, adequate storage facilities, and favorable structure are fulfilled. CLASSIFICATION OF OIL AND GAS LANDS. The immediate purpose of the classification of oil and gas land is to withhold from entry all lands containing valuable deposits of fluid hydrocarbons pending the enactment of adequate legislation providing for their disposition. The ultimate purpose of the classi- fication is to determine the position and extent of the areas whose value for their deposits of oil or gas, whether proved by actual drilling or indicated by favorable geologic conditions, is greater than their value for agriculture or other purposes and to provide for a disposition of the deposits in accordance with this greater value. 118 CLASSIFICATION OF THE PUBLIC LANDS. Classifications are made by the oil section of the land-classification board. This section consists of three geologists, in addition to the chief of the board. Each classification is based on data submitted by a field geologist, who is called into consultation at the meeting at which his data are considered. Other geologists having special knowledge of the area under consideration may also be consulted. The factors observed by the field geologist are reviewed in detail, and his inferences and conclusions are subjected to the severest tests of experience and theory. Each factor which can be conceived as having a bearing on the accumulation and present distribution of oil within the area under discussion is carefully considered in all its relations before an attempt at classification is made. The record data submitted by the field geologists consist primarily of a map or maps showing the facts observed in the field. On these maps surface contours and drainage are indicated and the details of the areal geology of the region are clearly shown. The position of all petroleum seepages and indications is recorded, as well as the location, by appropriate legend showing the results obtained, of each well drilled within the area examined. All determinations of dip and strike are shown, also the axial lines of all anticlines and synclines, with the direction and amount of pitch of each fold. The location of all land corners found is likewise noted, in order that the classifica- tion may conform to the established system of land surveys. Struc- ture sections are necessary to explain complicated structural condi- tions and indicate the relative thicknesses of the formations and the position of the productive -zones. Underground structure con- tours must be drawn to show the relative position of the principal oil-yielding zones above or below sea level, in order that the approxi- mate depth of the oil zone beneath any desired point in the field may be readily determined when the elevation of the point above sea level is known. In a field where considerable development work has been done the preparation of the data should include the plotting of all available well records and the correlation, if possible, of the several oil-yielding zones. The principal factors considered: by the board in determining the classification of an area are the stratigraphy, the structure, the continuity and character of the oil sands, the quality of the oil, and the presence or absence of water. In many fields the productive sands are confined to a single geologic unit, the formations above and below being uniformly barren. It is therefore necessary to know not only the number and relation of the productive zones in a particular succession of strata but also the geologic system or series and, if possible, the formation or group to which these zones belong. ‘The assignment of productive zones to a definite formation or group out- side of which the strata are known to be barren constitutes an im- OIL AND GAS LANDS. 119 portant step in the classification, the productive portions of the field being thus limited to the areas underlain by the petroliferous units and the areas not so underlain being at once disregarded as having no prospective value for oil. | As it is the structure of the petroliferous strata which largely de- termines the place of accumulation of oil and gas, it is apparent that a detailed knowledge of the structural conditions is absolutely essen- tial to classification. In the classification of areas whose structure is anticlinal all lands are classified as oil bearing which lie along the axes of the anticlines or which are so located on the flanks that the oil sand underlies them within an arbitrarily chosen limit of depth. This limit may be the depth below which it is estimated that drilling can not be profitably carried because of mechanical difficulties, or it may represent the distance from the axis beyond which it is consid- ered improbable that oil or gas in valuable quantities have accumu- lated. In monoclines similar considerations limit the distance down the dip to which classifications as oil land are carried. In the rarer synclinal accumulations the width of the zone classified as oil bear- ing depends mainly on what is known regarding the quantity of oil present. The thickness and porosity of the reservoir rock are important fac- tors to be considered with regard to the production and life of the wells, but their bearing on classification is subordinate, for classification is concerned with the boundaries of productive areas rather than with estimates of probable production. The continuity of the oil-bearing zone is, however, an important factor in classification, though, un- fortunately, it is one whose exact value can rarely be determined, because. of the difficulty of obtaining adequate data on the subject. In many areas of Tertiary rocks, where lateral variations in ltho- logic character within short distances are to be considered the rule and not the exception, changes in the thickness and extent of the oil- _ bearing zones must be expected, and although field examination may show the general trend of the variations in a certain region, local variations can seldom be predicted in advance of drilling. The determination of the duty of water, or the amount, of :watér: g necessary to irrigate a piece of arid land suitably, is another difficult: task of the engineer. In some parts of the West the necessary aniount. cart — of water has been determined by scientific study. Over the; greater» portion of this region, however, the amount has been. determiitied,,, 184 CLASSIFICATION OF THE PUBLIC LANDS. largely by experience, so-called, and has usually been greater than is necessary. Frequently the lower limit has been determined in dry seasons when the supply of water was meager. Therefore the duty of water is susceptible of a very flexible interpretation. On each irrigation project there is a generally accepted idea of the amount necessary, and whether a larger or smaller amount than this is de- livered by the canals is rarely determined. As a rule, however, the discriminating engineer can, by examining all the evidence, fix upon an approximate standard that may be considered reasonable, and unless that standard approaches too closely the total amount of water available adjustment is comparatively easy. Determination of the duty of water is, after all, an agricultural problem, some crops re- quiring more than others on the same land and different kinds of soils requiring different amounts for the same crops. Having deter- mined this amount, the engineer then measures or estimates the losses which occur in transmission through canals and other conduits from the source of supply to the cultivated fields, for duty of water is, unless otherwise specified, referred to the field itself. This amount is sometimes called the net duty. To the amount required for actual application to the crops must be added that lost by seep- age and by evaporation, and the farther the supply from the place of utilization the greater the amount which must be allowed for such losses. It is necessary also to consider losses in the storage reser- voirs, especially the loss due to evaporation. Having summed up all these items and having previously determined the total supply available, the engineer can then determine how much is available for new lands. To this quantity is applied the duty previously deter- mined, allowance being made for the prospective losses in the con- duits that will carry the water to the new land. The result of this computation will show the amount of new land that can be irrigated. CHARACTER OF LAND TO BE IRRIGATED. The elements in the investigation of the character of the lands to be irrigated include topography, geology, character and depth of soil, and general drainage conditions. These are partly engimeering and partly agricultural factors, but the engineer must take them all into consideration, because it is apparent that, with a given prospec- tive cost of irrigation, a project would be feasible if the soil and physical conditions were of one kind and not feasible if those condi- tions were of another kind. The climate is another essential factor, and a study must also be made of the kind of crops adapted to the particular locality. It is apparent that a greater investment can be made for irrigation in a region adapted to citrus fruits than in one where, on account of climate, soil, or altitude, hay is the principal | possible commodity. The determination of these peints by the engi- E a @ A T te ane CLASSIFICATION IN RELATION TO WATER RESOURCES. 185 neer rests largely on his general knowledge of related conditions and on the experience that has been gained by the people in the region. The transportation facilities and the market are subject to change and should usually be considered merely to determine whether pres- ent or future development is desirable. Transportation facilities wil, under ordinary conditions, be provided in response to produc- tion, and market is a feature which, in the long run and under the present conditions of rapid growth and consumption in this country, will ultimately offer few difficulties. CHARACTER OF IRRIGATION WORKS. Having reached a favorable determination as to water supply, duty of water, and the economic features above set forth, the engineer must then investigate the character of irrigation works that are adapted to the physical conditions of the area. The character of such works depends entirely on the physical problems to be met. It may be necessary to construct storage reservoirs in order to utilize the high- est possible proportion of the available water. On the other hand, the source of supply may be a very large stream, having a capacity sufficient to furnish all the water required for practicable irriga- tion in the entire region, and the studies are then confined to the determination of suitable diversion sites and canal routes reaching from the headworks to the lands to be irrigated. As in the case of reconnaissance power surveys, no final locations are determined by the engineer, it being considered preferable to leave such matters of detail to those who may in the future develop the project. The location of the headworks and of reservoirs and the routes, lengths, and capacities of canals can be determined approximately by field investigation of the type herein described, and while the results may be inaccurate for purposes of final location and development, they are sufficient to afford information suitable for departmental action. The public lands located in reservoir sites or along the courses of prospective conduits are carefully considered by the engineer with respect to their relation to the ultimate problem under consideration. METHODS OF CLASSIFICATION. PROCEDURE UNDER THE CAREY ACT In the administration of the Carey Act and its amendments classi- fication of lands with respect to irrigability is a necessary incident, for under the conditions of this act the land granted must be non- mineral, desert, and irrigable. The first step in the present pro- cedure is the withdrawal of lands under the act of March 15, 1910 (36 Stat., 237), at the solicitation of the State in which the lands are. . 186 CLASSIFICATION OF THE PUBLIC LANDS. situated. This is essentially a withdrawal for the purpose of classifi- cation, and the area withdrawn may be far in excess of that eventu- ally constituting the irrigable area of the project. The withdrawal is made on the assumption that the area includes some land sus- ceptible of irrigation under the Carey Act, but investigation may show this not to be the case. During the period of withdrawal, which is limited to one year, the promoter of the project has oppor- tunity to investigate the area, plan the details of the project, and make a reliable classification as to irrigability without fear of aliena- tion of the lands and resulting interference with the successful con- duct of the project. In case such investigations and a request by the State for segregation are not made, the land is restored to the public domain without classification. If, on the other hand, the plans for the project are perfected and application for segregation is made, the lands listed in the application are further reserved until action is taken on the case, and the remainder of the withdrawn lands are restored to the public domain and may thereafter be assumed to be nonirrigable. The regulations require that the application for segre- gation shall include full data to show that the land is nonmineral and desert land and is irrigable and that the project is feasible. A field investigation is made by the General Land Office and the case is referred to the Geological Survey for report. A careful analysis of the water supply of the project is then made by the Survey, and sufficient investigation of probable costs and returns is made to show whether the reclamation and settlement can probably be accomplished | at a cost warranted by the value of the reclaimed lands. If the existing data relative to the amount of water available for the project are insufficient to warrant. a reasonably definite conclusion as to the area that can probably be irrigated, a hydraulic engineer of the Geological Survey may be called upon to supplement them by stream gagings and such other determinations as seem advisable. When all the data are considered, an estimate of the allowable area is prepared and a definite report and recommendation on the case are made. Final adjustment of the area to be segregated and of the terms of the contract between the Secretary of the Interior and the State devolves upon the General Land Office. The approval of the segregation list under present departmental practice is in effect a fairly reliable classification of the land as non- mineral, desert, and irrigable. The aim of the work as now con- ducted is to safeguard the welfare of prospective settlers, the neces- sary investment of capital, and the interest of the Government. Some attention is being paid also to construction and settlement on Carey Act projects. When data obtained after the segregation is made indicate that the area included in a project exceeds the land CLASSIFICATION IN RELATION TO WATER RESOURCES. 187 that can be successfully irrigated, or when it is learned that con- = 2 27, 37, 45-46 Maximum pricey ot s__ Sees Cee 95 194 INDEX. Page Gq. x Coal Jands, prices .of 29228. 81, 95 uae restorations of 2022 ee) 52, 97-98 | Gaging stations, establishment of_ 173, 182 Walwatiomy Of 228 eo Peed hs 65, 79295 |\YGale; A. S): aworkvot: