UBRART SYLLABUS A COURSE OF LECTURES ECONOMIC GEOLOGY JOHN C. BRANNER, PH.D., Professor of Geology AND JOHN F. NEWSOM, A.M., Assistant Professor of Mining and Metallurgy IN LELAND STANFORD JUNIOR UNIVERSITY Second Edition STANFORD UNIVERSITY I9OO STANFORD UNIVERSITY PRESS PREFACE. This syllabus is intended for the use of students both while in college and afterwards. The outlines given can be expanded by notes taken from the lectures, from reading, and from observation, and written out on the opposite pages left blank for that purpose. One of the most important things a student of economic geology needs to learn is where to find and how to use information that has been pub- lished. We have therefore endeavored to give references: first, to the works on the general subject of economic geology ; second, to periodicals in which articles are to be looked for upon various economic subjects ; third, to papers and reports upon special subjects. The general works and periodicals are listed on pages iv and vi, and the references to special topics are given as foot-notes in the body of the sylla- bus under each topic. The list of references is not complete in any case, but it is usually sufficient to put the student in the way of finding other titles. By posting titles in the syllabus as the articles appear the student can add greatly to its usefulness, and in this way keep his own copy up to date. More space is given to the economic geology of the United States than to that of foreign countries. Some of the substances are necessarily but briefly treated. For the sake of uniformity the tons mentioned in this syllabus have all been reduced to short tons of 2,000 pounds. The compositions of minerals, unless otherwise stated, are the theo- retic ones, and are taken from Dana's System of Mineralogy. The charts showing the production, imports, and prices were made chiefly from the data of the United States Geological Survey. Space has been left on the right side of these diagrams so that the lines can be con- tinued for several years. A few blank pages are left at the back of the book for the addition of notes and memoranda on special subjects not treated in the syllabus. Inasmuch as most institutions in which economic geology is taught have courses of lectures upon mining law, the notes on that subject, given in the first edition of the syllabus, are left out of the present one. On page 346, however, a few references are given to important works on min- ing law. The authors are under special obligations to D. M. Barringer of Phil- adelphia for the use of the cuts illustrating the geological introduction to his "Law of Mines and Mining." GENERAL WORKS ON ECONOMIC GEOLOGY. Books and articles upon special subjects are mentioned under each topic. THE METALLIC WEALTH OP THE UNITED STATES. By J. D. Whitney. Phil- adelphia, 1854; 510 pages. Scarce. A TREATISE ON ORE DEPOSITS. By B. von Cotta ; translated from the Ger- man by F. Prime, Jr. New York, 1870; 575 pages. Scarce. ECONOMIC GEOLOGY. By David Page. London, 1874; 336 pages. POPULAR FALLACIES REGARDING PRECIOUS METAL ORE DEPOSITS. Ry Albert Williams, Tr. Fourth ann. rep. U. e. Geol. Survey, 257-271. Wash- ington, 1884. APPLIED GEOLOGY. By S. G. Willip.ms. New York, 1886; 386 pages. A TREATISE ON METALLIFEROUS MINERALS AND MINING. By D. C. DavieS. Fifth edition, London, 1892; 548 pages. A TREATISE ON 3ARTF.Y j :3 OTHER lINERALS AND MINING. By D. C. DavieS. Second edition, 'uondon, Io88; 336 pages. TRAIT^ DBS GIT^S MINERAUX KT METALLIFERES. Par Ed. Fuchs et L. de Lau-'oy. 2 vols. Paris, 1893, (Contains many valuable references.) ETUDE INDUSTRIELLE DE^ GITES METALLIFERES. Par George Moreau. Paris, 1894; 453 pages. ECONOMIC GEOLOGY OF THE UNITED STATES. By R. S. Tarr. New York, 1894; 509 pages. THE ORE DEPOSITS OF THE UNITED STATES. By J. F. Kemp. New York, 1893; second edition, 1895; 343 pages; third edition, 1900, 484 pages. THK GENESIS OF ORE DEPOSITS. Bv F. Posepny. Transactions of the Amer- ican Institute ( f Mining Engineers, 1893, XXIII, 197-369; also a separate publication of tl^ Institute. New York, 1895. A TREATISE ON ORE DEPOSITS. By J. A. Phillips. London, 1884; 651 pages. Second edition rewritten, etc. By Henry Louis. London, 1896; 943 pages. Mineral Statistics. THE MINERAL RESOURCES OF THE UNITED STATES. Published annually from 1883 to 1893 by the U. S. Geological Survey. Since 1893 these re- ports are included in the annual reports of the Director of the Sur- vey. THE MINERAL INDUSTRY. Editt:! by R. P. Rothwell. Published annually since 1893. Prior to 1893 the Engineering and Mining Journal pub- lished annually statistics of the mineral industries of the United States. The Director of tne Mint, publishes an annual report upon the pro- duction of the precious metals in the United States. The census reports. PERIODICAL PUBLICATIONS. 1. ANNALES DBS MINES. Published at Paris since 1794. 2. AMERICAN JOURNAL OF SCIENCE. Published monthly at New Haven, Conn., since 1819. 3. BULLETIN DE LA SOCIETE GEOLOOJIQUE DE FRANCE. Paris, France; one volume annually since 1830. 4. NEUES JAHRBUCH FUR MINERALOGIE, GEOLOGIE UND PALAEONTOLOGIE. Stuttgart, annually since 1830. 5. BERG- UND HUTTENMANNISCHE ZEITUNG. Leipzig since 1842. 6. QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY OF LONDON. One volume annually since 1845. 7. GEOLOGICAL MAGAZINE. Begun in 1858 as THE GEOLOGIST; continued since 1865 as THE GEOLOGICAL MAGAZINE. Published monthly at Lon- don, England. 8. ENGINEERING AND MINING JOURNAL. Published weekly at New York since 1866. 9. TRANSACTIONS OF THE AMERICAN INSTITUTE OF MINING ENGINEERS. New York ; one volume annually since 1870. 10. SCHOOL OF MINES QUARTERLY. Published quarterly at New York since 1879. 11. TECHNOLOGY QUARTERLY. Published quarterly by the Massachusetts Institute of Technology, Boston, since 1887. 12. AMERICAN GEOLOGIST. Published monthly at Minneapolis, Minn., since 1888. 13. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA. One volume an- nually since 1890. 14. JOURNAL OF GEOLOGY. Published semi-quarterly at the University of Chicago since 1893. 15. ZEITSCHRIFT FUR PRAKTISCHE GEOLOGIE. Berlin, Germany, since 1893. 16. ANNALES DBS MINES DE BELGIQUE. Brussels, since f896. 17. Monographs, bulletins, and annual reports of the United States Geo- logical Survey, Washington, since 1880. SUBDIVISIONS OF THE GEOLOGICAL COLUMN, OK ORDER OF THE STRATIFIED FORMATIONS. CHARACTERISTIC LIFE ERA PERIOD Man Recent _0 Pleistocene Terrace Cham plain Glacial Mammals q 0> Q Tertiary sssf K Eocene Cretaceous Upper Lower Reptiles esozok Jurassic Upper Middle Lower 5 Triassic Upper Middle Lower Permian Acrogens Coal Measures Amphibians Lower Carbon- iferous Fishes o Devonian Catskill Chemung Hamilton Corniferous Oriskany 1 Silurian g j or 'C Upper Silurian t Lower Helderberg Salina Niagara 1 nvertebrates 5 Ordovician co or Lower Silurian Trenton Canadian Cambrian Potsdam Acadian Georgian c 08 O> * Algonkian Keweenawan Huronian g <5 Archean Laurentian * Van Hise places the Algonkian as a separate formation between the Archean and Paleozoic. t Some geologists regard the Lower Helderberg as Devonian. ECONOMIC GEOLOGY. INTRODUCTORY. What is meant by economic geology; geology in its relations to arts and industries. Necessity of understanding pure geology before attempting to apply it. Geological products are used, directly or indirectly, in every branch of human industry. The prosperity of a nation depends largely upon its geo- logical products. Geology in its relations to agriculture. Soils are geological products. Soil belts of Tennessee, Kentucky, Indian*, Missouri. Residual soils varying with the rock. Soils transported by water: river bottoms; by ice: drift area of the United States. Fertilizers. Green-sand marls of New Jersey. Apatite deposits of Canada. Phosphates of South Carolina, Florida, Tennessee, and Arkansas. Land-plaster, or gypsum, of New York, Michigan, etc. Geology and forests.* Geology and industries. The great industries of nations, states, and cities are often determined by local geology. Relations of England's wealth and power to the mineral resources of that country. The wealth and power of the United States have increased in propor- tion to the development of our mineral resources. Note the commercial importance of various states, and how each owes its importance to some geological product, omitting purely mining and purely manufacturing states : Alabama: iron, coal. California: gold, quicksilver. Indiana: natural gas, building stone, glass, coal. Maine : granite. Michigan : copper, iron ore. *The relation between forestry and geology in New Jersey. By A. Hollick. Amer. Nat., Jan. 1899, XXXiil, 1-14; Feb. 1899, XXXIII, 109-116. 4 ECONOMIC GEOLOGY. Missouri : zinc, lead, iron ore, glass-sands, fire-clays. New Jersey : marls, clays, zinc. Ohio: coal, building stone, natural gas, petroleum. Pennsylvania: iron, coal, petroJeum. Tennessee: marble, //^-, (^AJ*^*>e t Vermont: marble. Cities and towns have often had their locations determined by the proximity to some mineral or mineral -bearing formation; others owe their importance to such proximity. Geology and art.* The local beginnings of ceramic art were made possible by the exist- ence of available clays. The great art manufacturing industries of Staf- fordshire, England, and of Limoges^ France, sprang up in those places partly because of the presence of the necessary clays in those regions. The influence of the clays of New Jersey and Ohio upon the pottery industries. Influence of Parian and Carrara marbles on sculpture. How the geology of Holland affected the landscape paintings of that country. Influence of building stones and brick-clays on architecture. Exam- ples : brownstones of New Jersey and Connecticut ; limestones of Mon- treal; brick-clays of Philadelphia, St. Louis, and Milwaukee. Geology and roads. Character of roads affected by local geology or by the presence or ab- sence of good road-making materials. Limestone "road-metal" of Southern France. Drift gravels of the glaciated portion of the United States. Jaspers of San Francisco and the Coast Ranges. Geology and railways. Location of railways often determined by the presence of minerals that promise business. Geologists employed by railways. Geology and migration. * Landscape geology. By Hugh Miller. Trans. Edin. Geol. Soc., 1892, VI, pt. Ill, 129 Also London, 1891. ECONOMIC GEOLOGY. MAPS AND SECTIONS FOE GEOLOGIC PURPOSES. When a geological deposit or formation has economic value, its precise location and distribution become important ; these can be shown by maps and sections. Advantages of maps over verbal descriptions. Maps may show horizontal location alone, or both horizontal and ver- tical position. Importance of horizontal location. Horizontal location determining ownership, extent, and value. How maps are made.* Regional maps; local maps. Every geologic map is based upon some kind of topographic map, and if a topographic map is not available one must be made. Knowledge of map-making indispensable to geologists. Triangulation. By U.S. Coast and Geodetic Survey; by U. S. Geological Survey; by Lake Survey ; special surveys. Chaining: telemeter or stadia measurements. t Plane-table surveying. t Advantages of finishing a map on the ground. Photo-topography . Maps made by reconnoissance methods. || Odometers; pacing; pedometers. Ordnance maps of England. * Outlines of field geology. By Archibald Geikie. London and New York, 4th ed., 1891. A manual of topographic methods. By Henry Gannett. Monograph XXII, U. S. Geol. Survey. Washington. 1893. The aims and methods of cartography. By Henry Gannett. Special publication, Mary- land Geol. Survey, vol. II. pt. Ilia. Baltimore, 1898. t A new prismatic stadia. By R. H. Richards. Jour. Assoc. of Eng. Socs., 1894, XIII. Topographical surveying by means of transit and stadia. By J. B. Johnson. New York, 1885. The theory of stadia measurements, accompanied by tables of horizontal distances and differences of level for the reduction of stadia field observations. By Arthur WiDslow. First report of progress in the anthracite coal region. Sec. Geol. Sur. of Pa., A A, 1883, pp. 325-344. Stadia surveying. By Arthur Winslow. Van Nostrand's Science Series, no. 77; New York. I A treatise on the plane-table and its use in topographic surveying. Appendix XIII, U. S. Coast and Geodetic Survey Rep. for 1880. Washington, 1882. I Photo-topographic methods and instruments. By J. A. Flemer. U. S. Coast and Geo- detic Survey Rep. for 1897. pp. 617-735. Washington, 1898. I The construction of topographic maps by reconnoissance methods. By Arthur Wins- low. Trans. Ark. Soc. of Engineers,' Architects, and Surveyors; 1888, vol. II, 75- Graphic field notes for areal geology. By Bailey Willis. Bui. Geol. Soc. Am., 1891, II, 177-188. 8 ECONOMIC- GEOLOGY. Maps made by the U.S. Coast and Geodetic Survey. Maps made by the U. S. Geological Survey. Maps made by the U. S. Land Office. Use of township sheets. Spanish grants and irregular surveys. Elevations. Vertical location upon maps shown by shading, hachures, or contours. , Importance of elevations in obtaining water supplies ; artesian waters ; mine draining ; prospecting for bedded deposits. Value of a common datum; advantages of mean tide level as a datum. Methods of determining elevations. Precise levels.* Ordinary spirit levels; hand level. Vertical arc; use of slide-rule in connection with arc observations. Mercurial barometer. Aneroid barometer. t Limitations of each method. The accuracy should depend upon the demands placed or likely to be placed upon the work. How sections are made. How geology is put on maps. How geology is put on sections. Relation of sections to the map. The importance of the proper location of structural features illustrated by synclines in the coal regions. The cost of errors. The difference between general geologic maps and those used for mining. The uses and advantages of an engineer's training in geological work. * Precise levels. Rep. U. S. Coast and Geodetic Survey for 1879, Appendix XV. Transcontinental line of geodetic spirit-leveling. Rep. U. S. Coast and Geodetic Sur- vey for 1882, Appendix XI. Washington, 1883. t A new method of measuring heights by means of the barometer. By G. K. Gilbert. Second ann. rep. U. S. Geol. Survey for 1880-81, pp. 403-562. How to use the aneroid barometer. By Edward Whymper. New York, 1891. The measurement of altitudes. By Henry Gannett. Mazama I, 343-264. Portland, Or., 1897. The barometric determination of heights. By F. J. B. Cordeiro. London, 1898. (Spon.) 10 ECONOMIC GEOLOGY. '""' _ North of Brazil North-south sections, ten miles apart, across an anticline in the coal measures of Indian Territory. The heavy black lines represent coal beds; the shaded areas represent shales, and the dotted areas sandstones. 12 ECONOMIC GEOLOGY. GEOLOGICAL SURVEYS. Immediate objects. Determining geological formations and structure. Exhibiting formations and structure on maps and sections. Ultimate objects. Turning maps and sections to account. Pure science : knowledge of former physical conditions. But original conditions often determined the contents of the rocks and hence their present values. Applied science : knowledge of the nature and distribution of deposits -of economic value. Methods. How the rocks are grouped ; the use of groups when valuable deposits are confined to certain ones. How groups or divisions are put on maps. Method with ordinary maps. Method with township sheets ; inaccuracies of township sheets. Method with special topographic maps. Method with maps in construction ; the advantages of exact loca- tions. Relations of map scale to geologic details. Field notes to be made on the spot. Field work usually best done with reference to the season and the weather. Office work can be done during inclement weather. Government Surveys. Necessity of knowing what geologic work has been done in a region to be investigated, and where the results have been published. European surveys.* The geological map of Europe. * [Geological survey of Great Britain.] By Sir A. Geikie. Geol. Magazine, July, 1898, V, 306-317, 358-366. The national geological surveys of Europe. By William Topley. Brit. Assoc. Rep. for 1884, pp. -221-240. London, 1885. Cost of European geological surveys. By E. A. Schneider. Eng. and Min. Jour., Oct. 10, 1896, p. 342; Oct. 17, 1896, p. 366; Oct. 24, 1896, p. 392. 14 ECONOMIC GEOLOGY. U. S. geological surveys.* Exploring expeditions with geological attache's. Wheeler survey, U. S. Engineers, War Department. Hayden survey, under the Department of the Interior. Powell survey, Department of the Interior. King survey, 40th parallel, under the War Department. Present U. S. Geological Survey, under the Department of the Interior. Duties as denned : to make a geologic map of the public domain. Scope of work. Paleontology, economic geology, topography, mineral statistics, hydrography, irrigation, chemistry, physics, engraving. Publications. Annual reports since 1880 (quartos) ; contents. Monographs (quartos) now number 38 volumes; contents. Bulletins (octavos) now number 159 on geology and 3L on water- supply and irrigation. Mineral resources (octavos) from 1882 to 1893; since 1895 they form part of the annual reports (quartos). Folios of the geologic atlas of the United States, 55 published; show topography aud geology, with brief descriptions. How the U. S. Survey reports may be obtained. State geological surveys. State surveys usually established for economic purposes. Purposes and success often depend upon the state geologist. Methods of selecting state geologists: appointment, election. Methods and results of typical state surveys. The New York survey. Pennsylvania survey. Arkansas survey. Political surveys. Boards of commissioners or control. Relations of national and state surveys. Aid of state surveys by the U. S. Coast and Geodetic Survey. Aid by the U. S. Geological Survey. * Surveys of the Territories. House miscellaneous document no. 5. 45th Cong., 3d ses. On the organization of scientific work of the general government. By J. W. Powell. Washington, 1886. Testimony before the Joint Commission. Senate mis. doc. 82, 49th Cong., 1st ses. Washington, 1886. Relations of state and national geological surveys. By J. C. Branner. Proc. Amer. Assoc. Advancement of Science, XXXIX. 219-237. The geology of government explorations. By S. F. Emmons. Presidential ad., Geol. Soc. Washington, 1896. Official geology. By H. H. Stoek. The Mining Bulletin, II, 38-52. [State College, Pa.] March, 1896. 16 ECONOMIC GEOLOGY. Publications. Annual reports. Bulletins. Monographs. Publication of field notes; objections to such reports. Cost of state surveys. Appropriations by legislatures. Special provisions for surveys. Private geological surveys. By scientific societies and exploring parties. By private corporations. Northern Pacific Eailway, coal companies, and other mining com- panies, for business purposes. By individuals. 18 ECONOMIC GEOLOGIC DEPOSITS. ECONOMIC GEOLOGIC DEPOSITS. The nature of geologic products. Great variation in characters in single classes. Structual materials: stone, glass-sand, slates, asphaltum. Fuels: coal, oil, gas. Ores of base metals: iron, zinc, lead, tin, copper. Ores of the precious metals : gold, silver. Precious stones: diamonds, emeralds, rubies. Earthy minerals : clays, bauxites, fertilizers, chalks. The origin of geologic deposits. Geological deposits of economic value orginate in ways as widely dif- ferent as the deposits themselves. They may be classified according to the processes of their formation as (1) mechanical; (2) chemical; (3) igneous: (4) organic. The following are illustrations : I. Mechanical deposits: building stones, grindstones, marls, clays, sands, some limestones and marbles. Mechanical concentrations: placer gold, some diamonds, some tin. II. Chemical deposits from concentration : salt, gypsum. Deposits from solution on exposure: stalactites, " onyx " marble. Deposits from solution on relief of pressure or lowering of temperature or both ; many important ore deposits. III. Poured out as igneous rocks. Crystallized out in rock masses : feldspar, rutile, diamonds, emery, certain precious stones. IV. Organic deposits from plants : peat, coal; from animals: tripoli. some limestones. Distillations from organic deposits: petroleum, gas, asphaltum, ozokerite. Any of these deposits are liable to be changed by metamorphism, and many deposits owe their value to their having passed through such changes. Some marbles are metamorphosed limestones. Slates are metamorphosed clay shales. Anthracite is changed coal. Coal is changed peat. Kaolin is decayed feldspar. Some polishing powders are decayed cherts or novaculites. Relation of the method of its formation to the form and distribution of a deposit of economic value. 20 CLASSIFICATION 'OF GEOLOGIC DEPOSITS. The classification of economic geologic deposits. The classification of geologic deposits is a matter of convenience, and the basis of the classification must be determined by the purposes for which it is intended. It may be based upon : I. Geographic distribution. National, state, and local reports. II. The minerals contained. This would group together all similar minerals, regardless of their origin, geographic or geologic position. Example : hydrocarbons of different origins, various compositions and occurrences. III. Geologic distribution, or that of the rocks containing the minerals. Relations of such grouping to historical geology. IV. Shape of the deposits. Classifications of ore deposits by different writers. Yon Cotta's.* 1. Regular deposits. 2. Irregular deposits. Whitney 's.t 1. Superficial. i Constituting the mass of a bed. 2. Stratified -. Disseminated through sedimentary beds. ( Deposited from solution, metamorphosed. ( Eruptive masses. | Disseminated in eruptive rocks. ( Irregular Vein matter precipitated from solution on the walls of cavities. Methods of filling cavities. Deposition from solutions by cooling and relief of pressure. (Fig. 13.) Sublimates deposited by solfataric action. Origin of the mineral-bearing solutions. Theory of ascending waters. Sandberger's theory of lateral infiltrations.* Relation of structural features of a region to the origin of different deposits. B. The replacement of one mineral by another. Examples of such replacement in the silicification of corals, wood, and shells, and the replacement of organic matter by iron pyrites. This process is called metasomatic replacement. Replacement in dolomitization. -=- _,_ _il - ,-v J ^/%^\ _QQiOMlTE L L V ^ >5Srn!SS Fig. 15. Horizontal plan of Fig. 14. Fig. 14. Vertical section in a quarry at Kilkenny, Ireland, showing the unaltered limestone and dolomite. (Prestwich.) C. The enlargement of veins by accretion. Enlargement of quartz grains. Illustration of needle ice and crystallization in the soil. The size, form, and structural relations of certain geodes due to en- largement, t Evidences of the mechanical force of the process. Possible relations to vein enlargement and to brecciation. (Fig. 16.) * Canadian Naturalist, new ser., 1877, VIII, 345-363. American Geologist, Dec., 1896, p. 393. t Formation of dikes and veins. By N. S. Shaler. gul. Geol. Soc. America, 1899, X, 38 FORMATION OF ORE-BODIES. III. Deposits of recent date, at or near the surface.* The usual classification of mineral deposits as " surface deposits " is open to the objection that many of these are ho longer either at or near the surface. Examples: bog iron of Carboniferous age; placer gold of Cretaceous age.t Surface deposits are local, and are forming at present: they are formed (1) by mechanical concentration; (2) by chemical action. Many valuable deposits that are not classed as ores are formed by these methods. Examples : many phosphates ; salt; gypsum; kaolin; rnonazite sands ; and others. Fig. 16. A geode formed in the stem of a crinoid. The accretion started in the hollow stem, burst it, and pushed the fragments apart. Two views of the same specimen: natural size. I. Deposits formed by mechanical concentration. These result from the decay of rocks and the mechanical concentration of the minerals contained. Examples : Stream and littoral deposits. Placer gold. Stream tin. Magnetic sands. Brazilian diamonds. II. Deposits formed by chemical action. Surface deposits from chemical action or chemical alterations at the * For references see titles given under the heads of the minerals mentioned as examples, t Auriferous conglomerate in California. By R. L. Dunn. Twelfth rep. State Mineralo- gist, 1893-94, pp. 469-471. 40 FORMATION OF ORE-BODIES. surface result in many ways. Examples of such deposits are bog iron ores, salt, gypsum, nitre, soda. Incrustations of smithsonite. " Mexican onyx." Some ore-bodies and deposits, though not necessarily deposited by chemical action, owe their value to chemical alterations at or near the surface. Residuary deposits produced by chemical (and mechanical) action and concentration. Manganese ores of Arkansas, Georgia, Virginia, and Brazil. Gossan, the altered part of a lode. Kaolins and clays by decomposition. Fullers' earth in Arkansas. FEATURES OF ORE DEPOSITS. FEATURES OF ORE DEPOSITS. The features of ore deposits, their shape, structure, and general rela- tions, depend partly upon the methods of their formation, that is, whether they were laid down as bedded deposits contemporaneous with their accompanying rock beds, or were deposited later in cavities, or occur as replacements. General forms. Shapes of cave deposits. Example: Marble Cave, Missouri. Shapes of bedded deposits determined by the conditions of deposition. Example : the iron ores of Pennsylvania. Thinning out; causes. (Pig. 17.) Shapes of fissure deposits. Fissure veins. Gash, lenticular, bedded, and contact veins. Fig. 17. Lens-shaped masses of manganese mterbedded with sedimentary rocks. Fig. 19. Reversed faults in horizontal rocks that have broken the original beds but left them parallel. Fig. 18. Gash vein in magne- sian limestone of Wiscon- sin. (Chamberlain.) Figs. 20-21. Illustrations of single veins repeated by faulting that left the different pieces parallel. 44 FEATURES OF ORE DEPOSITS. Irregularities of thickness ; cause of pinching out. Irregularities of direction, outcrop, dip, and strike. Groups of veins (Fig. 22) ; feeders ; ore-shoots or chutes and chimneys. Parallelism of veins. Produced by torsion or other fractures, or by bedding. Complications produced by faulting. (Figs. 19, 20, 21.) Effect of vertical displace- ments; of lateral dis- placements. (Fig. 24.) Complications by intersec- tion of several ore deposits. Mother lode of California 112 miles long.* Relations to other lodes. Size and extent of ore deposits. Uncertainties regarding the size and form of ore-bodies. Fig. 23. Parallelism of coal beds produced by the original bed- ding of the rocks. Fig. 24. Section showing both vertical and horizontal faulting of a vein. Enterprise mine, Rico, Colorado. (Rickard. j 1 Geology of the mother lode regfon. By H. W. Fairbanks, Tenth ann. rep. State Mir ing Bureau of California, pp. 23-90- 46 FEATURES OF ORE DEPOSITS. Internal and structural features. Banded structure produced by crustification. Brecciated structure produced by cementing of fractured materials. Fig. 25. A vein brecciated on one side and Fig. 26. Ore-bearing quartz vein. The coun- banded on the other. try rock is altered, but contains no ore. (Lindgren.) Fig. 27. Quartz vein along the foot-wall of a porphyry dike, with stringers running off into the porphyry. (Lindgren.) Fig. 28. Vein with its ores extending into the altered country rock. (Lindgren.) Definitions of terms. Hanging-wall; foot- wall; country rock. Selvage, gouge, or flucan is the clay seam between vein and wall- rock. Possible relation of clay to the vein matter. Ore. Gangue. Association of ores and gangues. Some veins sharply defined ; others merge into their walls. (Figs. 25, 28.) Distribution of ores in veins. Distribution due to variation in size of the vein. 48 FEATURES OF ORE DEPOSITS. Distribution due to other causes. Bonanzas are ore pockets or local enlargements of the vein. Horses; stringers (Fig. 27); chutes; chimneys. Effect of change of dip on the character of the lode. Effect of country rock on the lode.* Ore-bodies often found at the contact between two formations. Fig. 29. A horse with the vein pass- Fig. 30. Contact deposits in the neck of an ex- ing around it on both sides. Figs. 31-32. Examples of contact deposits or ore-bodies at the contact between two different kinds of rock. Fig. 33. Contact deposits in limestone beneath shale. Fig. 34. Superficial alteration of a contact deposit. Ores affected by superficial alteration, t Oxidation at the immediate surface. Gossan, Colorado, chapeau de fer, eisener hut. Origin of these names from the rusty brown color of the oxi- dized ores. * An inquiry into the deposition of lead ore. By L. Bradley. London, 1862. t The superficial alteration of ore deposits. By R. A. F. Penrose, Jr. Journal of Geol- ogy, vol. II, pp. 288-317. 50 FEATURES OF ORE DEPOSITS. Why free gold near the surface is replaced by sulphides in depths. Depths to which alterations extend and the nature of the changes with various ores. Iron ores. Copper ores in Chili affected to 1,500 feet. Lead. Silver in Granite Mountain, Montana, to 900 feet. Gold. Zinc changed to carbonate to the depth of weathering. Effect of these changes upon the value of the ores. Different treatment required for the unaltered ores. Fig. Sfc^Ideal section showing the superficial alteration of iron ores in Michigan and Minnesota. U. 4,Q. lIL U. %>A, , i+ ii , 15. 3- ; 31 , 52 IRON. IRON.* Importance of iron. Prevalence of iron in rocks. Iron is seldom found in the native state ; some meteorites are native iron. The ores of iron: oxides, carbonates, sulphides. Oxides : anhydrous ; hydrous. Anhydrous. Hematite ( Fe2 Oa ), oxygen 30, iron 70, if chemically pure. Most important of American ores. Specular iron. Red hematite, " kidney " ore when reniform. Fossil ore. Itabirite, iron schist. Red ochres. Magnetite ( Fes Oi ), oxygen 27.6, iron 72.4. Magnetic ore; often titaniferous.t Franklinite deposits of New Jersey. Hydrous oxides. Limonite, or brown hematite (2Fea Oa . 3H-2 O), oxygen 25.7, water 14.5, iron 59.8. Bog iron ; how formed. Ochres (excepting red ochre). Other forms of limonite. Carbonates. Siderite, or spathic iron ( FeCOa ), carbon dioxide 37.9, iron pro- toxide 62.1, equivalent to 48.2 metallic iron. Clay ironstone. Blackband. Brown carbonate. Sulphide. (Iron pyrites, FeSa ), sulphur 53.4, iron 46.6. Used in the manufacture of sulphur and sulphuric acid. (See under Iron Pyrites.) Impurities found in the ores of iron. Phosphorus makes iron "cold short." * HiBtory of the manufacture of iron in all ages. By James M. Swank. Philadelphia, The iron manufacturer's guide. By J. P. Lesley. New York, 1859. t A brief review of the titaniferous magnetites. By J. F. Kemp. School of Mines Quar- terly, July, 1899, XX. 323^356; Nov., 1899, XXI, 5^-65. L . 18(. - I oJ 9 6 <^^_ a , . li^M^ , in>-? /I' 54 IRON. Sulphur makes iron brittle at a red heat (" hot short ") and destroys its welding power. / Silica. Titanium. . Copper. $ Arsenic. Antimony. Processes have been devised for using ores containing impurities. The Thomas-Gilchrist process of steel making uses pig iron high in phosphorus. The Clapp-Griffiths process permits much phosphorus when silicon is carefully excluded. In general the impurities that damage ore for one purpose may be beneficial for some other. The properties that determine the value of iron ores. The Bessemer process of decarburizing cast iron, by which steel is cheapened. Bessemer ore should not contain more than 0.05 per cent, phosphorus. Non- Bessemer iron ore. Distribution of the ores of iron. Geological. Iron is found in all ages, but is of more importance in some than in others. Pre-Cambrian iron of Lake Superior. Cambro-Silurian iron of Brazil. Silurian ore of Missouri. Archean, Cambro-Silurian, Silurian, and Carboniferous iron belts of the Appalachians. Tertiary iron of Texas and Arkansas.* Iron deposits forming at the present time. Geographical distribution. Foreign iron regions. United Kingdom, Germany, France, are the principal foreign pro- ducers. Other countries. Distribution in America outside of United States. The iron ores of Brazil, Cuba, and Canada. IRON REGIONS OF THE UNITED STATES, t There are three general regions : Appalachian region ; Lake Superior re- gion ; western region. The iron deposits of Arkansas. By R. A. F. Penrose, Jr. Geol. Survey of Ark., for 1892, 1. Little Rook, 1892. tThe mining industries of the United States (exclusive of the precious metals). By Raphael Pumpelly. Tenth census, XV. Washington, 1886. # A- . fO I - 56 IRON. /. The Appalachian region: Ores mostly non-Bessemer. Iron occurs in four general northeast-southwest belts following the geological structure. Beginning with the easternmost, these are : Archean belt: Ores chiefly lenticular deposits of magnetite in gneisses and other metamorphic rocks. This belt is most important in the Adirondacks New York, New Jersey, and Virginia. Cambro-Silurian belt : Ores chiefly non-Bessemer limonites, associated with schists, limestones, and clays. This belt is most important in Virginia, Alabama, Tennessee, and Pennsylvania. Upper Silurian belt : Ores non-Bessemer red hematites, " fossil ore," limited to the Clinton beds, which contain inter- calated beds of iron ore almost everywhere that they occur. They are of the greatest importance in the Bir- mingham, Ala., district, where they are the chief source of supply. Carboniferous belt : Carbonate ores are of little importance at present. Western Pennsylvania, Ohio, and Kentucky ores are of this type. The most important producing states in the Appalachian region (in the order of their importance in 1897) are: Alabama:* Production in 1897, 2,350,456 tons, worth 66 cents per ton at the mines. Ores: Non-Bessemer hematites in the Clinton beds (Upper Silurian) are the most important. Brown hematites (limonite) belonging to Cambro-Silurian belt are also important. Associated rocks. Birmingham is the chief district.. Pennsylvania: Product in 1897, 810,591 tons; value per ton at the mines, $1.05. Ores : The Archean magnetites and Cambro-Silurian limonites in the eastern part of the State are the most important ; Hematites and carbonates are of little importance. Virginia:* Production in 1897, 796,463 tons; value per ton at the mines, $1.22. Ore : Chiefly limonite. Geological relations of the ores. The Rich Patch deposits. t (Figs. 36, 37.) * Iron-making in Alabama. By W. B. Phillips. Geol. Survey of Ala., 1896; 2d ed., 1898. t The Rich Patch iron tract, Virginia. By H. M. Chance. Trans. Am. Inst. Min. Eng. 1899. J Geol. Atlas, U. S. G. S. Staunton folio. 1894. 58 IRON. Tennessee:* Production in 1897, 677,037 tons; value per ton at the mines, $0.71. Ores : Red hematite and limonite of non-Bessemer quality. Localities and geological relations of the Tennessee ores. Other producing states in the eastern or Appalachian region are : New York : Ores chiefly magnetites from Archean rocks. Also Cambro-Silurian. (Fig. 38.) New Jersey : Magnetites in Archean rocks. Georgia, North Carolina, Ohio, Kentucky. Relative production and geological relations of the ores. J+^ w.( n**-n$. > *y COPPER. Fie 57 Section of the Globe copper mine, Maricopa county, Arizona. The limestone is of Carboniferous age. (Wendt.) n^S^ Porphyry Fig. 58. Section across Longfellow Hill and Chase Creek Canyon, Longfellow copper mine, Clifton district, Arizona. (Wendt.) Fig. 59. Section of Metcalf Hill, Clifton copper basin, Arizona, (Wendt.) UJ ^n . 3- -7 U- j e-^, ^W^ \rt~t - *1 7 , A^v . 3 J - 3 ^ . 1 , B ^ , MA^ - 1 s5T ) - . 3 , ixv-0 . Y 5 . ( I 7U. 84 COPPER. Nature of the Butte ores. Copper sulphide and silver. The upper 400 feet leached of copper ; the lode first worked for silver. Bornite and chalcocite below. Character of the deposits. In fissure veins. III. The Arizona copper region.* Three copper-producing districts in southeastern Arizona. 1. The Globe district. Character and occurrence of the ores. 2. The Clifton district. /*- Character and occurrence of the ores. 3. The Bisbee district. Character and occurrence of the ores. Other copper districts of the United States. New Mexico. Calif ornia.t Copperopolis ; Iron Mountain mines at Keswick. Utah. Colorado. Wyoming. Missouri : chalcopyrite with chert in Cambrian magnesian limestones. New Jersey. Tennessee, Vermont. t Relative importance of the different regions in the United States. American copper mines compared with foreign mines. Effect of metallurgical processes upon cost of production. Importance of the electrolytic process. * The copper ores of the southwest. By Arthur F. Wendt. Trans. Amer. Inst. Min. Eng., 1887, XV. 25-77. The Copper Queen mine, Arizona. By James Douglas. Trans. Amer. Inst. Min. Eng., The mines of Yavapai county, Arizona. By J. F. Blandy. Eng. and Min. Jour., June, 1897, LXIII, 632. t Copper resources of California. By Herbert Lang. Eng. and Min. Jour., April. 1899, LXVII, 442, 470. J The pyrites deposits of the Alleghanies. By A. Wendt. School of Mines Quarterly, VII, 154-188, 218-235, 301-323. New York, 1886. Copper deposits of Vermont. By H. A. Wheeler. School of Mines Quarterly, IV, 219. ^t. . - * 3 ^o, t, 6 & 1.. d A^JLo^i^ &*^A^ ,7, /3^e_, " ^*-JO Fig. 60. Comparative output of copper in the chief copper-producing countries since 1878. Total Production t Arizona Production *b Lake Superior Production H Montana Value of Exports 000000 000000 5 300000 000000 000000 000000 Fig. 61. Statistics of the production of copper in the United States since 1850, and the value of copper exported since 1864. TIN. TIN.* Uses of tin. Manufacture of alloys. Pewter. Bronze - ? Whi-tt Porphyry Lime'Stoni \nn Mat trial H-^xl Grey Porphyry Whdti Limestone, "Fig^iSectionTon the "gold orejchute" of Iron Hill, Leadville, Colorado. (Blow.) Fig. 76. Northwest-southeast vertical section through Spar ridge and Vallejo gulch, in the Aspen district, Colo. Washington shaft is shown near Vallejo gulch. * Geology of Colorado and western ore deposits. By Arthur Lakes. Denver, 1893. t Geology and mining industry of Leadville, Colorado. By S. F. Emmons. Monograph XII, U. S. Geol Survey. J Geology of the Aspen mining district, Colorado. By J. E. Spurr. Monograph XXXI, U. S. Geol. Survey. Washington, 1898. 116 SILVER. Creede. Ores : oxides in fissure veins in igneous rocks. Cripple Creek.* Other Colorado districts : Eagle River, Ten Mile, Monarch, Rico, Red Mountain, Custer county. t Montana. Butte City region, i Ores: native silver and galena in veins with quartz gangue containing some Mn ; country rock of granite. Granite Mountain. Ores : ruby silver associ- ated with gold in veins in gray granite. Other Montana silver re- gions are: Cook City, Flint Creek, Glendale. Utah. Big and Little Cottonwood Canons. Ores: oxidized lead - silver ; in bedded veins in Carboniferous limestone. Beaver county. Oxidized lead-silver ores occur in contact fissures (Horn Silver mine) ; in cham- bers in limestone (Cave mine) ; in fissure veins (Carbonate mine). Summit county. Ores in veins through quartzite (Ontario mine). Other silver regions of Utah are Bingham Canon, the Mercurdistrict, the Tin- Fig. 78. Section showing faults and ore-bodies in the Bushwhacker-Park Regent mine, Aspen. (Spurr.) tic district, Silver Reef. * Geology and mining industries of the Cripple Creek district, Colorado. By W. Cross and R. A. F. Penrose, Jr. Sixteenth ann. rep. U. S. Geol. Survey, pt. II, 13-309. Washington, 1895. t The mines of Custer county, Colorado. By S. F. Emmons. Seventeenth ann. rep. U. S. Geol. Survey, pt. II., 405-172. Washington, 1896. t Silver mining and milling at Butte, Montana. By W. P. Blake. Trans. Amer. Inst. Min. Eng., XVI, 38-45. Notes on the geology of Butte, Montana. By S. F. Emmons. Trans. Amer. Inst. Min. Eng.. XVI, 49-62. < Economic geology of the Mercur mining district, Utah. By Emmons and Spurr. Six^ teenth ann. rep. U. S. Geol. Survey, pt. II, 343-455, 118 SILVER. MESTONE v COARSE ANOSTO Fl GRAINED O CUART2 fjf HHOOOCHHOSITf. (SS) ORE I ENTERPRISE MINE," COLORADO. Fig. 79. Section exposed in a breast of the Enterprisi Colorado. (Rickard.) Nevada. The Comstock lode,* the largest silver-gold deposit ever discovered, is a great fissure vein, four miles long, several hundred feet broad, with branch- ing ends; it follows a fault line; the greatest displacement is at the centre, where it is nearly 3000 ft. The mines reach a depth of about 3000 ft. mine at Rico, Dolores county. Fig. 80. East-west section through the Com- stock lode in Nevada, showing the posi- tion of two of the ore-bodies, and of the Sutro tunnel. * Geology of the Comstook lode and the Washoe district. By G. F. Becker. Monograph III, U. S. Geol. Survey. Cjmstook mining and miners. By E. Lord. Monograph IV, U. S. Geol. Survey. 120 Development and importance. Ores : high grade, associated with gold. Ores in bodies irregularly distributed through the quartz gangue; bonanzas. The country rock is diorite and diabase. Theories of the origin of the ores. The Eureka district.* Ores : oxidized lead-silver, with some gold irregularly distributed through veins in often brecciated Cambrian limestones and shales. Depth of altera- tion of ores over 1300 feet. Idaho. The Cteur d'Alene district. The ore is galena with siderite gangue in country rocks of highly folded schists andquartzites. Wood River district. Ores largely altered by surface oxidation. Irregularly distributed in limestones. New Mexico. Lake Valley district. Ores: galena, ceruesite, and chloro-bromides in Paleo- zoic limestones. The silver districts about Silver City. Arizona. Tombstone region. Ore : horn silver, associated with galenite, free gold, pyrite, lead carbonate. Geologic relations. Other silver regions of the United States. California produces some silver as a by-product of gold. Texas, Washington, Dakota (the Black Hills), Michigan, North Caro- lina, Oregon, Alaska, are all silver producers. The produc- tion in 1893 ranged from 349,400 ozs. in Texas to 9,600 ozs. in Alaska, in the order named. Relative importance, t Effect of coinage legislation upon the price and output of silver. Fig. 81. Section across a vein In the Hillside mine, Yavapai county, Arizona, showing the ore scattered through clay. (Rickard.) * Silver- lead deposits of Eureka, Nevada. By J. S. Curtis. Monograph VII, U. S. Geol. Survey. Geology of the Eureka district, Nevada. By Arnold Hague. Monograph XX, U. S. Oeol. Survey, t Production of the precious metals la the United States. By Clarence King. Second ann. rep. U. S. Geol. Survey, 883-401. 122 SILVER. SILVER OUTPUT OF THE LEADING STATES. (Commercial value.) Years. Colorado. Montana. Utah. Idaho. Arizona. 1895 1896 11,687,150 15 097 500 9,835,305 10 548 120 4,296,115 5 933 526 2,236,951 3 623 400 561,174 1 34' 7 000 1897 12,722,227 10,049,112 3,999,804 3,587,400 796 577 1898 1899 13,866,535 8,743,011 3,876,451 3,707,999 1,622,500 1900 Fig. 82. The silver output of the principal silver-producing countries since 1880. Fig. 83.~The value of the silver production of the United States since 1845, and the price per ounce of silver since 1856. 124 GOLD. GOLD.* Uses. Gold has been used from the earliest times in coinage and for orna- mental purposes. Coinage. The stability in value of gold coin. Ornamental purposes, foil, dentistry, medicine. Ores. Most of the gold mined is found as native gold ; often alloyed with silver and other metals. California gold contains from 11 per cent, to 13 per cent, silver; Australian gold contains 5 per cent, silver, and the percentage is increasing. Other combinations are : Sylvanite (Te 62.1, Au 24.5, Ag 14.4, variable). fC Nagyagite (one analysis, Te 30.52, S 8.07, Pb 50.78, Au 9.11 + Ag and Cu. Other analyses yield: Te 15.11 up, S to 10.76, Pb to 57.16, Au 7.41 to 12.75). Ci^^Jr,^ ^ 5 * Petzite (Au 25.5, Ag 42.00, Te 32.58, variable)./^ a^\ 3. Modes of occurrence. Gold is found : In veins, as free gold, and in combination. Gangue generally quartz; exceptions. t Mining vein deposits. Milling, + concentrating. The chlorination process is based upon the "property of chlorine gas to transform metallic gold into sol- uble chloride of gold." Gold must be metallic. The cyanide process is based upon the principle that a dilute solution of cyanide of potassium dissolves gold and silver. || * Contributions to the bibliography of gold. By A. Liversidge. Proc. Austral. Assoc. Adv. Sci., Jan. 1895, pp. 240-256. This contains titles not given in Lock's Gold. Gold. By A. G. Lock. London, 1882. (Bibliography.) La geographic de Tor. Par A. de Foville. Ann. de Geographic 6me Ann^e, Paris, 1897, pp. 193-211. L'or dans la nature. Par Cumenge et Robellaz. Paris, 1898. t Gold in granite. Trans. Amer. Inst. Min. Eng., 1896, XXVI, 290-298. Amer. Jour. Sci., April, 1896, CLI, 309-311. t Gold mill practices. By E. B. Preston. Bulletin 6, California State Mining Bureau. Sacramento, 1895. g The extraction of gold by chemical methods. By T. K. Rose. Nature, March, 1897, LV, 448-9. U The cyanide process. By A. Scheidel. Bulletin 8, California State Mining Bureau, 1894. (Reprinted, London, 1895.) The cyanide process of gold extraction, By James Park. Auckland, New Zealand. Melbourne, 1898. (132pp.) 126 GOLD. In stream or placer deposits, as flakes, grains, or nuggets. Origin of placer gold. Beach deposits. Stream deposits. Geographic changes subsequent to their deposition. The high terrace gravels of the Sierras.* Methods of mining placer deposits. Panning, sluicing, booming, dredging, t amalgamation. Fig. 84. Theoretical section showing the origin of the auriferous gravels. The dark lines represent gold-bearing veins, of which the coarser and heavier materials accumulate in the valleys. Distribution. Gold is one of the most widely distributed elements : it is found in rocks of all ages and kinds, and is even a constituent of sea water. The principal gold-producing countries were : 1898. 1899. 1900. 1901. South African Republic. .$78,070,761 United States 65,082,430 Australasia 62,294,481 Russia 24,734,418 Mexico 8,236,720 British India 7,765,807 China 6,641,190 Colombia 3,700,000 South African deposits. J Though long known, the gold deposits of the Transvaal have been worked only since 1886. * Age of the auriferous gravels of Nevada. By W. Lindgren. Jour. Geol., 1896, IV, 881 t Dredging for gold in southern rivers. Eng. and Min. Jour., 1897, LXIIL 211-212. A practical treatise on hydraulic mining. By Aug J. Bowie, Jr. New York, 1893. Notes on gold dredging. By J. B. Jacquet. Mineral Resources [of New South Wales], No. 3 Sydney, 1898. Recent gold dredges. Eng. and Min. Jour., Dec., 1898, LXVI, 728-9. I The deposition of gold in South Africa. By S. Czyszkowski. Amer. Geologist, 1896, The gold mines of the Rand. By F. H. Hatch and J. A.Chalmers. London and New York, 1895. (306pp.) Diamonds and gold in South Africa. By Theo. Reunert. Johannesburg, 1893. The Witwatersrand gold field and its working. By L. de Launay. Eng. and Min. Jour., June, 1897, LXIII, 631, 659. The Witwatersrand gold fields, banket and mining practice. By S. J. Truscott. Lon- don and New York, 1898. Les mines d'or du Transvaal. Par L. de Launay. Paris, 1896. Auriferous conglomerate of the Transvaal. By G. F. Becker. Amer. Jour. Sci., March, 1898, V, 193-208. 128 The gold yield of the Witwatersrand fields increased from about $400,000 in 1887 to $73,677,000 in 1898. Gold in quartz conglomerate beds, occasionally broken by faults or dikes. Simplicity of geologic structure as compared with other gold fields. Fig. 85. Section through shafts in the Rand gold field showing the structure and con- tinuation of the beds at great depths. (Hatch and Chalmers.) Fig. 86. Section of the Glencairn property in the Rand, showing portions of the four reefs or bedded ore deposits. (Hatch and Chalmers.) Fig. 87. Section across the reefs of the Rand showing the faulting. (Hatch and Chalmers.) 130 GOLD. Fig. 88. Section across saddle-reef folds at Hargreaves, New South Wales. The black areas represent the ores. (Watt.) Australasian gold fields.* The gold-producing colonies in the order of output. Victoria, New Zealand, New South Wales, Queens- land, West Australia, Tasmania, and South Australia. Veins and lodes are called " reefs." " Saddle reefs " in the Ben- digo fields of Victoria and in the Hargreaves fields of New South Wales. Gold in Russia.^ Gold regions of the United States. The Appalachian region. *" Gold was first discovered in the United States in 1799 in North Carolina. Between 1843 and 1848 the annual production was near $2,000,000. Gold occurs in quartz veins, in slates, gneiss, and schists, and in the resid- ual clays derived from these rocks. Rocks Ar- chean or lowest Paleo- zoic. Fig. 89. Section across anticlinal and syn- clinal saddle reefs at Tambaroora, N. S. Wales. (Watt.) Fig. 90. Section of a "saddle reef," or iode, New Chum Consolidated mine, Ben- digo gold field, Victoria, Aus- tralia. (Schmeisser.) * The genesis of certain auriferous lodes. By John R. Don. Trans. Amer. Inst. Min Eng., 1897, XXVII, 564-668; 993-1003. The gold fields of Australasia. By K. Schmeisser. London, 1898. Mining and milliner gold ores in western Australia. By H. C. Hoover. Eng. and Min. Jour., Dec., 1898, LXVI, 725-726. t The gold placers of Siberia. Eng. and Min. Jour., Jan., 1897, LXIII, 90. The industries of Russia, IV, Mining and metallurgy. By A. Keppen. St. Peters- burg, 1893. f. c. ; <3 . 9. 132 Fig. 91. Section through the Bendigo gold fields, Victoria, Australia, showing the saddle reefs. (Schmeisser.) Gold is mined in Virginia, N. Carolina,* S. Caro- lina, Georgia, t The Rocky Mountain district. Colorado.* Gilpin county: gold with pyrites in fissure veins through gneiss. Boulder county : gold as tel- luride ores, in small veins, along fault planes, in granite or gneiss, associated with porphyry. Clear Creek county: gold in fissure veins through granitic rocks. * Gold mining in North Carolina and adjacent southern Appalachian regions. Bulletin 10, Geol. Sur- vey of North Carolina. Raleigh, t Gold deposits of Georgia. By Yeates, McCallie and King. Bul- letin 4, Geol. Survey of Georgia, 1896. Gold mining in Georgia. By William Tatham. Jour. Franklin Insti- tute, July, 1898, CXLVI, 19-26. I Geology of Colorado and western ore deposits. By Arthur Lakes. Penver. 1893. Fig. 92. Vertical section showing the forking of the Pike's Peak vein, Cripple Creek district, Colorado. (Penrose.) 134 GOLt). Lake county: the Leadville district is in this county ; gold in limestone associ- ated with porphyry, in porphyry dikes, in veins through granite, and in placers. Teller county : the Cripple Creek region ;* ore native gold, and tellurides in fis- sures and associated with dikes. The country rocks are eruptives. (Figs. 92- 97.) San Miguel county : Telluride district.! Fig. 93. Section in the Elkton mine, Cripple Creek district, showing the relation of the vein a to the dike b and to the country rock c. (Penrose.) Fig. 94. Horizontal section in the Elkton mine, Cripple Creek district, Colorado, show- ing the relation of the vein a to the dike 6 and to the country rock c. (Penrose.) N.E. Pig. 95. Section in the Victor, Smuggler Lee, and Buena Vista mines. Cripple Creek district, showing the parallel ore-bodies (a). (Pen- rose.) Fig. 96. Another section showing the form of the ore-body in the Victor. Smuggler Lee, and Buena Vista mines, Cripple Creek district, Colorado. (Penrose.) Fig. 97. Section showing the forms of the vein in the Blue Bird mine, Crip- ple Creek district. The ore is shown black, 6 is the country rock. (Pen- rose.) * Geology and mining industries of the Cripple Creek district, Colorado. By W. Cross and R. A. F. Penrose, Jr. Sixteenth ann. rep. U. S. Geol. Survey, pt. II, 1-209. Washington, 1895. t Mining industries of the Telluride quadrangle. By C. W. Purington. Eighteenth ann. rep. U. S. Geol. Survey, pt. Ill, 751-848. Washington, 1898. 136 (SOLD. ig. 98. Diagrammatic section ihowing the contact of porphyry and limestone and the zone of ore deposition, Maginnis mine, Ju- dith Mountains, Montana. (Weed and Pirsson.) Wyoming and South Dakota: the Black Hills region. Gold in schists, in Cambrian sandstones, in segregation veins, and in placers of Pleistocene age. Montana. Silver Bow county: gold in plac- ers near Butte. Deer Lodge county : gold in plac- ers and quartz veins ; also in granite, where silver in large quantities is often associated with it. Lewis and Clarke county : gold in placers, near Helena, and in quartz veins through granite and slate. Fergus county : gold chiefly in deposits associated with igneous rocks.* Idaho, t Boise county: placers developed in 1863. Alturas county : gold associated with silver in quartz veins. The Great Basin region. Utah. Salt Lake county : Bingham Canon ; gold associated with silver in bedded quartz veins. Mercur district :+ in the Oquirrh Range, Utah. Gold (probably originally deposited as telluride) occurs na- tive (where altered by weather) and as tellurides, in altered limestones, mostly along the under sides of thin intruded porphyry sheets, but sometimes in the por- phyries themselves, and in the limestones immediately above them. The ores were deposited by agencies ascending along fracture planes. The rocks of the locality are Lower and Upper Carboniferous sandstones and limestones, aggregating 12,000 feet in thickness; they are exposed along a low anticlinal arch* (Spurr.) Nevada. White Pine county : Egan Canyon ; gold with silver occurs in quartz vein traversing slate. * Geology and mineral resources of the Judith mountains of Montana. By Weed and Pirsson. Eighteenth ann. rep. U.S. Geol. Survey, pt. Ill, 689-616. Washington, 1898. t The mining districts of the Idaho basin and the Boise' ridge, Idaho. By W. Lindgren. Eighteenth ann. rep. TJ. S. Geol. Survey, pt. Ill, 635-719. Washington, 1898. t Economic geology of the Mercur mining district. By J. Edward Spurr, with intro- duction by S. F. Emmons. Sixteenth ann. rep. U. S. Geol. Survey, II, 343-455. 138 GOLD. The Comstock lode:* gold with silver, in a great quartz vein, with country rock of diorite and diabase. Ore in rich masses, bonanzas. Proportion of gold to silver, 2: 3. The Pacific Slope region. California, t Gold occurs : In quartz veins in slates of Devonian and Carboniferous, but found mostly in Triassic and Jurassic rocks.? In placers derived from the quartz veins. River gravels. High gravels. Origin and age of the high gravels. || Extent of the California gold fields. The mother lode.H Methods of mining. Quartz mining. . Hydraulic mining. River and bar mining. Dredging. Oregon. Gold in quartz veins and placers, as in California. At Port Orford gold occurs in beach sands. * Geology of the Comstock lode and the Washoe district. By George F. Becker. Mon- ograph III, U. S. Geol. Survey. Washington, 1882. Comstock mining and miners. By E. Lord. Monograph IV, U. S. Geol. Survey. Wash ington, 1883. t California mines and minerals. Published by the California Miners' Association. San Francisco, 1899. t Characteristic features of California gold quartz veins. By W. Lindgren. Bulletin Geol. Soc. Amer., VI, 221--240. 1895. Gold ores of California. By H. W. Turner. Amer. Jour. Sci., June, 1894, CXLVII, 467-473. Further notes on gold ores of California. By H. W. Turner. Amer. Jour. Sci., May, 1895, p. 374. Gold quartz veins of Nevada City and Grass Valley districts, California. By W. Lind- gren. Seventeenth ann. rep. U. S. Geol. Survey, pt. II, 1-864. Washington, 1896. I The auriferous gravels of the Sierra Nevada of California. By J. D. Whitney. [Cam- bridge], 1880. Mineral resources of the United States west of the Rocky Mountains. By J. Ross Brown. Washington, 1868. Ancient river beds of the Forest Hill divide. By R. E. Brown. State Mining Bureau [Calif.], 1890, pp. 435-465; also 1880-82, pp. 133, 190. The auriferous gravels of California. By J. H. Hammond. Ninth rep. State Mineralo- gist [Calif.] for 1889, pp. 105-138. Auriferous gravels of the Sierra Nevada. By H. W. Turner. Amer. Geologist, XV, June, 1895, p. 371. The gold regions of California are shown on U. S. Geol. Survey folios: 3, Placerville; 5, Sacramento ; 11, Jackson; 15, Lassen Peak; 17, Marysville; 29, Nevada ;City; 37, Downieville; 41, Sonora; 51, Big Trees. II Old river beds of California. By J. Le Conte. Amer. Jour. Sci., 1880, CXIX, 176. Ancient channel system of Calaveras county. By W. H. Storms. State Mining Bu- reau [Calif.], 1893-94, pp. 482-492. \ Geology of the Mother Lode gold belt. By H. W. Fairbanks. Amer. Geol., 1891, VII, 209-222. Tenth ann. rep. State Mineralogist [of California], 1890, pp. 23-90. Eng. and Min. Jour., 1896, LXII, 248. The mother lode of California. By Ross E. Brown. California Mines and Minerals, 57-72. San Francisco, 1899. 140 GOLD. Fig. 99. Section through Table Mountain, Tuolumne county, Gal., showing old river auriferous gravels covered by a bed of lava, and the method of tunneling to reach them. At the sides are shown river gravels of later age. Fig. 100. Section through the Red Point and Damm channels from El Dorado canyon (right) to Humbug canyon, California, showing the auriferous gravels covered by lava, and the method of reaching them by tunneling. The dotted lines at the sides suggest the ancient outlines of the hills. TREADWELL MINE -HO'/ Fig. 101. Section through the Alaska-Treadwell mine, Douglas Island, near Juneau, Alaska. 142 GOLD. Washington. Gold has been mined from placers. Alaska.* Placer deposits and quartz veins. Cape Nome beach placers, t The Juneau district. (Fig. 101.) Michigan. The gold production of the most important gold States. Statistics.* Effect of silver legislation on gold production. * Geology of the Yukon gold district, Alaska. By J. E. Spurr. Eighteenth ann. rep. U. S. Geol. Survey, pt. Ill, 101-392. Washington, 1898. Reconnaissance of the gold fields of southern Alaska. By George F. Becker. Eigh- teenth afln. rep. U. S. Geol. Survey, pt. Ill, 1-86. Washington, 1898. t The new gold fields at Cape Nome, Alaska. By Ivan Brostrom. San Francisco, 1899. Cape Nome gold district. By F. C. Schrader. Nat. Geogr. Mag., Jan., 1900, XI, 1&-23. Eng. and Min. Jour., Dec., 1899, LXVIII, 727. t Statistics and technology of the precious metals. By Emmons and Becker. Tenth Census, vol. XIII. Washington, 1885. 144 GOLD. $140 RUSSIA AFRICA CHINA BRITISH INDIA Fig. 102. The gold yield of the chief gold-producing countries sin Fig. 103. The comparative gold production of the several States sin 146 PLATINUM GROUP. METALS OF THE PLATINUM GROUP. Platinum.* Platinum is a rare metal; it is heavy, silver-white, ductile, and fusible only at a very high temperature (1779 C.). Fig. 104. The largest platinum nugget ever found in America. Natural size, 3"x2%"; weight, nearly two pounds ; from the west coast of South America. (Baker & Co., Newark, N. J.) Uses. It was used for coinage in Russia from 1828 to 1845. In chemical, electrical, and surgical apparatus. Ores. Native platinum occurs alloyed with the other metajs of the platinum group. It is often associated with gold. Sperrylite (PtAa,).* /^JK__ 5J-J7* ) Treatment. / J Occurrence. It is usually mined from placers, where it is often found associated with gold. At the Gongo Soco mines of Brazil it was taken with gold from decayed shistose rocks. * Bibliography of the metals of the platinum group, 1748-1896. By J. L. Howe. The mineral industry, vol. I, 373-397. New York, 1893. /' iv. S . <} ->1 148 PLATINUM GROUP. Distribution. Platinum is mined at but few places in the world. Most of the world's supply comes from the Ural Mountains of Russia.* Borneo, Australia, Colombia, and British Columbia all supply small amounts. Brazil formerly furnished a considerable quantity. Discovery reported in New South Wales. t The gold mines of California yield some platinum. Statistics. Iridium. Iridium is a rare metal, extremely hard, lustrous, and steel-white. It has a very high melting point, and is not attacked by any single acid. Uses. In alloys : standard weights and measures. As a coloring matter in photography, ceramic art, and jewelry. In pointing gold pens, fine tools, and in the knife-edges of delicate balances. Iridium plating. Occurrence. Iridium is found as iridosmine (alloy of iridium with osmium) associ- ated with platinum, in Colombia, province of Choco; in the Urals of Russia; in Australia; it is found also in the gold-bear- ing beach sands of northern California. Iridium occurs alloyed with platinum. Very little iridium is used, the world's production being but a few tons annually. Osmium. Osmium is the heaviest and most difficultly fusible metal known (never been fused). Uses. It is "used in the form of iridosmine for pointing pens and fine tools. Osmium occurs alloyed with iridium (iridosmine), and alloyed with platinum. *Daubr6e: On platinum in the Urals. Comptes Rendus de 1'Academie des Sciences, 1875, LXXX, 707-714. The platinum deposits of the Tura river-system, Ural mountains, Russia. By C. W. Purington. Trans. Amer. Inst. Min. Eng., Feb., 1899, XXIX. Eng. Ming. Jour., March 25, 1899, LXVII, SiO-Sol. Sur 1'industrie de Tor et du platine dans TOural. Par M. Laurent. Annales des Mines, Nov., 1890. t Eng. and Min. Jour., Feb. 22, 1896, LXI, 182; Aug. 8, 1896, LXII, 126, 220; April, 3, 1897, LXIII, 333. The occurrence of platinum in New South Wales. By J. B. Jacquet. Records of the Geol. Survey V, pt. I, 33-38. [1896.] 150 PLATINUM GROU!>. PaUadium. Palladium is ductile and malleable ; it is a whitish steel-gray metal with metallic lustre. Uses. For finely graduated scales. Compensating balance wheels and hair springs for watches. Some mathematical and surgical instruments. Occurrence. Palladium occurs alloyed with platinum and iridium. 152 TUNGSTP:N. TUNGSTEN. Tungsten is never found in the native state, and the pure metal is seldom produced artificially. Uses. Ferro-tungsten. Tungsten added to steel in small proportion (2 to 12 per cent.) gives greatly increased hardness and brittleness.* As a mordant. Ores. Wolframite (FeO 19.16, MnO 4.96, WO 3 75.88, individual analysis). Scheelite, calcium tungstate (CaO 19.4, WO 3 80.6). Occurrence. Tungsten is usually found associated with deposits of tin ; it is found at many places, but is produced at few. Cornwall, Saxony, Bo- hemia, Australia, and New Zealand produce practically all the tungsten of commerce. The total production of Europe in 1892 was 263.3 tons. In New South Wales.t Tungsten is not produced in the United States. It occurs, and at- tempts have been made to work it, in Connecticut at Monroe and Trumbull, and in Maine near Blue Hill Bay. It has been found elsewhere, but no attempts at mining have been made. * Alloys of iron and tungsten. By F. L. Garrison. Sixteenth ann. rep. U. S. Geol. Sur- vey, pt. Ill, 615-623. Washington, 1895. Relative resistance of tungsten and molybdenum steel. By R. Helmhacker. Eng. and Min. Jour., Oct. 8, 1898. LXVI, 430. t Tungsten ores in New South Wales. By J. E. Carne. Mineral Resources [of N. S. Wales], no. 2. Sydney, 1898. 154 MOLYRDKNUM. MOLYBDENUM.* Molybdenum is a white metal with a silvery lustre ; it is as malleable as iron; its sp. gr. is 9.01. Use. Principal use is in the manufacture of molybdenum steel. Ores. Molybdenite, the sulphide (MoS.; = Mo 59, S 41), is the principal source of supply; it is lead gray in color, very soft, and greatly resembles graphite. Wulfenite (Pb Mo 4 = MoO 3 39.3, PbO 60.7). Modes of occurrence. Molybdenum does not occur in the native state. Molybdenite usually occurs as disseminations or veins in granite or gneiss. Distribution. The metal is produced in commercial quantities in but few places. In the United States: 9,550 Ibs. of the metal, valued at about $1.25 per lb., were produced in 1898; 2,000 Ibs. ferromolybdenum (50% Mo) were produced the same year. New Mexico and Ari- zona are the sources of supply. Formerly the chief supply of the world has come from Sweden. * The mineral industry, vol. VI, 485-186: vol VIT. 51 1-516. / / & Of 3 156 ANTIMONY. ANTIMONY. Antimony: metal with a tin-white color, crystalline structure, and very brittle; it fuses at a low temperature (430 C.). Uses. Medicine. Pigments, q. v. Alloys : Alloyed with other metals, antimony gives a hard and brittle product. Type-metal is an alloy of antimony with lead and bismuth ; when less than 15 per cent, antimony is used the product expands on cooling. Babbitt metal is an alloy of tin with antimony and copper (Sn 83 per cent., Cu and Sb 17 per cent.). Pewter is an alloy of lead and tin with antimony, bismuth, or copper. Britannia metal is an alloy of tin with antimony and other metals. Ores. Stibnite (Sb 71.4, S 28.6). Senarmontite (Sb 83.3, O 16.7). S Kermesite (Sb 75.0, S 20, O 5). Stibnite is the most important. It is soft, has a metallic steel-gray color, and will melt in a candle flame. Occurrence. Antimony usually occurs in veins with a quartz gangue. Distribution. The principal antimony-producing countries of Europe are those ad- jacent to the Mediterranean. France is the most important antimony producer in the world : an- nual output about 5,000 tons. Portugal, Spain, Austria-Hungary, Italy, Asia Minor, Servia, and Macedonia all produce some. Borneo and Japan are large producers : annual output from 3,000 to 4,000 tons. Other regions are Australia, Nova Scotia, New Brunswick. - U. %>. ( -2 ^ 'A , >. a 194 COMPOSITION OF COALS. (Individual cases.) Quality ' Water Sulphur Ash Fixed Carbon Volatile Hydro- carbon Lignite* f 12.45 0.56 12.45 35.53 39.00 70 86 3 56 78 99 15 87 Semi-bituminous Anthracite 0.74 2.49 4.06 0.65 9.96 8.54 72.60 83.96 12.61 4.34 * These two analyses of lignite are of the same specimen, one haviner been made shortly after the lignite was taken from the mine, the other after it had air-dried for one month. Classification by fuel ratio. Formula: Fuel ratio = fixed carbon Bituminous Semi-bituminous Semi-anthracite Anthracite volatile hydrocarb*n ' 1 to 5. 5 to 8. 8 to 12. 12 to 99. This classification may or may not hold in trade. Effect of water in coal ; objection to lignite. Effect of sulphur; aids combustion but attacks grates and boilers; injures pig iron. Fixed carbon determines steaming value of bituminous coals. Influence of fixed carbon in manufacturing coke. Volatile hydrocarbon in gas manufacture. Influence of the physical properties of coal. Cannel coal. The coal supply. Statistics of production. The structural features of coal make it easy to compute the available coal supply. Consumption of coal in the United States. Increase of output, past and future. Difficulties of determining the period of exhaustion. Possibility of working thinner beds. Decreasing loss. Possibility of utilizing other sources of energy. Natural gas. Petroleum. Waterpower available through electric transmission. The waste of coal. Not more than 10 per cent of the energy of coal is utilized. The amount of coal in the world is limited, and all unnecessary waste should be avoided, f'fr. ^ 196 COAL. Waste in using through loss of heat; imperfect combustion. Waste in getting. In England the loss was formerly two- thirds ; now one-fourth. The coal waste commission of Pennsylvania* estimates the total loss in the Anthracite region at from 65 per cent to 70 per cent, and that this will be reduced to 60 per cent. This loss is constant for the whole region, but varies greatly with individual mines. Waste in pillars, 30-45 per cent of the whole bed. How they may be saved. Longwall mining. t Waste in blasting. Wedging, mining machinery. J Effect of strikes on the use of machinery. Waste in sorting, 7 per cent of what is mined. Influence of thin beds of shale in coal bed. Waste in handling. Breaker waste, 24-32 per cent of what goes to the breaker. Culm heaps of the anthracite regions. Results of different methods of breaking and screening. Gyrating screens. Waste in shipping. The amount of loss affected by the friability of the coal. Waste is much less now than formerly. Waste caused by leaving behind beds that would become valuable in the future. Utilization of coal waste. Burning culm on special grates. || Made into briquettes and eggettes.H Extensively used in Europe. Pulverized fuel ; doubtful results. Filling mines. Importance of stacking coal waste and other waste separately. Utilization of peat.** * Report of commission on waste of coal mining (in Pennsylvania). By E. B. Coxe and others. Philadelphia, 1893. t Eng. and Min. Jour., Nov. 21, 1896, LXII, 487; April 10, 1897, LXIII, 350. J Coal-cutting machinery. By E. W. Parker. Trans. Amer. Inst. Min. Eng., 1899, XXIX. I Winslow in ann. rep. Geol. Survey of Ark., 1888, III, 105. || Burning anthracite culm. By John R. Wagner. Cassier's Mag., Nov., 1895, IX, 1-26. The yield of the Reynolds anthracite culm bank. By A. D. Smith. Eng. and Min. Jour., April 15, 1899, LXVII, 440. 5 Patent fuel and its manufacture. By C. Archibald. Jour. Fed. Can. Min. Inst., 1898, II, 288. ** On peat and its uses. By T. S. Hunt. Canadian Naturalist, Dec., 1864, 1, 426-441. Turf (peat) briquettes in Germany. By John E. Kehl. U. S, Consular reps., LIX, 98. C++JL 198 COAt. TOT/M.FKOOUC AMTHRACITE- PENNSYLVANI ILLINOIS WtSTVl Fig. 117. Comparative production of coal in the chief coal-mining States since 1880. 200 GRAPHITE. GRAPHITE, PLUMBAGO, OR BLACK LEAD. Graphite is pure carbon, having a greasy feel and a black metallic lustre. Uses* Best qualities for lead pencils and crayons. Its most important use is for making crucibles and other refractory materials. As a lubricant; advantages : not affected by cold, heat, or air.t Inferior grades for stove polish. In electrotyping. Occurrence. Most abundant in old metamorphic rocks. Vein-like deposits. Bed-like deposits. Theory of its organic origin. t Graphite found in pig iron : why. Distribution. Widely distributed, but mined in few countries. The leading producers in the order of their importance at present are : Austria, Ceylon, Germany, Italy, United States, and Japan . Product of the Alibert mine, Siberia, used for the best pencils. Ceylon product noted for its purity. Austria.^ The Austrian deposits are in gneiss and schist ; in places eighteen feet thick. Ceylon. The veins are in gneiss ; some of the graphite 99.79 per cent carbon. Germany. In Bavaria a vein in gneiss sometimes 16 feet thick; product impure. * Der Graphit und seine wichtigsten Annendungen. Von Dr. Heinrich Weger. Berlin, 1872. t Mineral industry, 1898, VII, 385-387. t Coal converted into graphite. By A. Taylor. Trans. Edin. Geol. Soc., 1874, II, 368. Origin of grahamite. By I. C. White. Bui. Geol. Soc. Amer., 1899, X, 284. g La geologic et 1'exploitation des gites de graphite de la Boheme M6ridionale. Par M. Bonnefoy. Annales des Mines, 7 ser., 1879, XV, 157-208. 202 GRAPHITE. Japan; Italy; India.* Canada.* In veins and thin seams in Lauren tian rocks ; most important deposits in Province of Quebec. United States. Many occurrences. The only mines worked are those at Graphite, near Ticonderoga, N. Y., and at Cranston, R. I.J At the latter place it is associated with anthracite. It occurs in the Coal Measures of New Mexico. In Gunnison county, Colorado, are graphite beds 2 feet thick. In Albany county, Wyoming, it occurs in veins. In California, mixed with kaolin; importance and difficulty of separa- tion. * Manual of the geology of India. Economic geology. By V. Ball. Calcutta, 1881, pp. 50-58. t Quar. Jour. Geol. Soc., 1869, XXV, 406. Amer. Jour. Sci., 1870, C, 130. t A graphite mine. By R. H. Palmer. England Min. Jour., Dec. 9, 1899, LXVIII, 694. UNITED STATES- AUSTRIA CEYLON ITALY GERMANY > 1 1 u 1 1 i Fig. 118. The production of graphite in the principal countries since 1872. 204 PKTROLEUM. PETROLEUM AND NATURAL GAS.* These substances are so related that it is convenient to discuss them together. The hydrocarbon series is natural gas, naphtha, petroleum, mineral tar, asphalt. Petroleum is formed from naphtha by loss of volatile matter and oxidation ; petroleum oxidizes to mineral tar or ozokerite, which oxidizes to asphalt. Petroleum, t Uses. In its crude condition. Lubricating, fuel, driving engines. After being refined, as Kerosene, gasoline, and paraffine, for illuminating and heating. Benzine for paints and varnishes. Vaseline for medicinal and other purposes. Naphtha, rhigolene, cymogene. Origin.* Mendeljieff's theory (1877): water in contact with hot carbides of metals, especially of iron, decomposes ; oxygen unites with iron ; hydrogen takes up carbon, ascends, and condenses to oil and gas. Objection to this theory. Generally accepted theory that oil and gas are slowly and sponta- neously distilled from organic matter. Deposits of organic origin in accompanying beds. Diatomaceous beds in California. Diatoms contain oil.|| * Report on the production, technology, and uses of petroleum and its products. By S. F. Peckham. Tenth Census, vol. X. Washington, 1884. Petroleum and natural gas. By Joseph D. Weeks. Eleventh Census. Report on min- eral industries, 425-578. Petroleum. By B. Redwood and G. T. Holloway. 2 vols. [Lippincott Company, Phila- delphia.] Le petrole, 1'asphalte et le bitume au point de vue geologique. Par A. Jaccard. Paris, t Composition of the American sulphur petroleums. By C. F. Mabery. Jour. Franklin Inst., June-July, 1895. Several articles by Sadtler, Peckham, and Day, in Proc. Amer. Phil. Soc., 1897, XXXVI, t The origin of petroleum. By O. C. D. Ross. Geol. Magazine, 1891, pp. 506-508. Beitrage zur Theorie der Petroleumbildung. Von Leopold Singer. Wien, 1893. On the origin of petroleum. By Richard Anderson. Trans. Geol. Soc. Glasgow, 1871-74, IV, 174-177. Petroleum: its history, origin, occurrence, etc. By Wm. Brannt. Philadelphia, 1894. I Geological probabilities as to petroleum. By Edward Orton. Bui. Geol. Soc. of Amer- ica, 1898, IX. 85-100. || Canadian Diatomaceag. By W. Osier. Canadian Naturalist, 1870, V, new ser. 143. t ILL \ 7 <^~ ut n ~J V /2**-i^~ , ; >f 10. 206 PETROLEUM. Geology. Oil and gas in sedimentary rocks of almost all ages. Diffused through many rocks where it is now useless ; possibility of distilling oil-bearing shales.* Association of gas, oil, and salt water; necessity of studying them together. Essential conditions are the same in all fields. t Rocks containing accumulations of oil and gas are : 1. Conglomerates or porous sandstones (Pennsylvania, New York, West Virginia, Kentucky). 2. Porous limestones (Ohio and Indiana). Why other rocks in the same places contain no oil or gas. Why Trenton limestone yields oil in some places and not in others. Origin of porosity of sandstone ; porosity of limestone due to dolomitization ; joint cavities in shales. Theory of oil caves ; caving of crust. Importance of overlying ' impervious beds to confine oil and gas. Relations of structure to accumulations of oil and gas. (Figs. 120, 121, 123.) Accumulations are local ; not found wherever the rock is found. Why oil and gas accumulate in some places and not in others. T. S. Hunt's anticlinal theory of oil.J Why anticlines are only locally productive. How monoclines may serve the same purpose. Influence of gentle and violent folds. How folds are recognized and located. Oil found in highly disturbed areas pockety, and its distribution diffi- cult to determine. Necessary conditions : 1. Source from which the oil is distilled. 2. Adjacent porous rock to hold it. 3. Impervious cover. 4. Structural features favoring accumulation. Where petroleum and natural gas are not to be sought. Crystalline or eruptive rocks. Relations of oil, salt-water, and gas. * A practical treatise on mineral oils and their by-products. By I. I. Redwood. London and New York (Spon.). tThe geology of petroleum and natural gas. By W. Topley. Geol. Magazine, 1891, VIII, 508-511. t Petroleum and natural gas. [By I. C. White.] West Virginia Geol. Survey, 1899, I, 223-378. Notes on the history of petroleum or rock oil. By T. S. Hunt. Canadian Naturalist, August, 1861, VI, 249. The anticlinal theory of natural gas. By I. C. White. Bui. Geol. Soc. of Amer., 1892, III, 204-216. 208 PETROLEUM. Rock pressure of oil and gas : In western Ohio from 650 Ibs. to square inch down; usually be- tween 300 and 400 Ibs. In Indiana from 325 to 250 Ibs. In Pennsylvania and West Virginia the highest recorded is 1000 Ibs." The highest pressure reported is 1525 Ibs. in New York State. Origin of rock pressure.* Lesley's theory of expansion of gas. Orton's theory of hydrostatic pressure. Trenton rocks outcrop on Lake Superior. Orton's law : Rock pressure of Trenton limestone gas is due to a salt- water column measured from about 600' a. t. to the level of stratum yielding gas. How practically demonstrated. Why oil wells of Pennsylvania are " watered out." Applicability of this law modified to other territories. Decrease of rock pressure. In Indiana the average pressure was originally (1888) 325 Ibs; in 1897 it was 191 Ibs. ; in November, 1898, it was 173 Ibs.t Artificial pressure used. PETROLEUM IN THE UNITED STATES. The salt industry the forerunner of petroleum industry. Boring for salt water; early drill; seed bag. High price of whale oil. Oil from cannel coal and shale. E. L. Drake's successful effort to get oil by boring at Titusville, Pa., in 1859. t Low price from over-production. Spouting wells; spread of exploration. The Pennsylvania, New York, West Virginia area. The Pennsylvania oil field centers at Oil City; the West Virginia field at Sisterville. First considerable flowing well struck in 1861; 300 barrels a day. * Consideration of the pressure, composition, and fuel value of rock gas. By J. P. Lesley. Ann. rep. Geol. Survey of Pennsylvania for 1885, pp. 657-680 Origin of the rock pressure of natural gas in the Trenton limestone of Ohio and Indiana. By Edward Orton. Bui. Geol. Soc. of America, 1890, I, 87-98. t Twenty-third ann. rep, Geol. and Nat Hist. Survey of Indiana, 1886. Indianapolis, 1899. I The first oil well. By J. S. Newberry. Harper's Magazine, Oct., 1890, LXXXI, 723-729 The oil regions of Pennsylvania. By William Wright. New York, 1865. (275 pp.) \ Oil and gas fields of Western Pennsylvania for 1887-88. By J. F. Carll. Geol. Survey of Pennsylvania. Harrisburg, 1890. The oil and gas regions. By J. F. Carll. Part II, ann. rep. Geol. Survey of Pennsyl- vania for 1886. Harrisburg, 1887. Petroleum; its production and products in Pennsylvania. By A. S. Bolles. Ann. rep Bureau of Industrial Statistics, 1892. Harrisburg, 1893. 210 PETROLEUM. Phillips' well 3,000 barrels a day. A well near Bradford that yielded 25,000 barrels in 1875, yielded 6,500,000 in 1878, and 23,000,000 in 1881. 6,358 wells put down in 1890. The western Ohio, Indiana area.* The Ohio oil fields center at Lima ; the Indiana fields center at Montpelier. Oil and gas from Trenton limestone. Confined by Utica shale. Rocks gently folded. In 1889 single wells in Ohio began with a yield of 10,000 barrels per day. Colorado region: Florence, between Pueblo and Canon City. Oil from Cretaceous shales. General structural features. California regions, t Oil from the Tertiary. Relations to diatomaceous earths. Wyoming district. i Limits of the supply of petroleum. Order of gas, oil, and water in producing wells. Sequence of their exhaustion. Natural process of distillation slow. Good but dearer oil can yet be manufactured from shale. Locating oil wells. How far geology may be depended upon. The elements of uncertainty. Indications of oil in the rock; "Trenton rock"; "surface indica- tions." Oil may or may not appear at the surface. Method of drilling. Growth of deep well drilling in America. Determining the geological position of the drill. The use and preservation of borings. * Report of the Geol. Survey of Ohio. Vol. VI, Economic geology. By Edward Orton. Columbus, 1888. The Natural gas field of Indiana. By A. J. Phinney. Eleventh ann, rep. U. S. Geol. Survey, 1889-90, pp. 617-742. First ann. rep. Geol. Survey of Ohio. By E. Orton. 55 et seq. Columbus, 1890. Petroleum, natural gas, and asphaltum in western Kentucky. By E. Orton, Frank- fort, 1891. t Oil- and gas-yielding formations of Los Angeles.Ventura, and Santa Barbara counties, California. By W. L. Watts. Bui. 11, Calif. State Mining Bureau, 1896. The genesis of petroleum and asphaltum in California. By A. S. Cooper. Bui. 16, Calif. State Mining Bureau. San Francisco, 1899. I The petroleum of Salt Creek, Wyoming. Petroleum series, Bui. I of the School of Mines, University of Wyoming. Laramie, 1886. 1 4 ABRASIVES. ABRASIVES.* Diamond Dust. (See pages 174-178.) Corundum, t Corundum for abrasive purposes ; forms not available for precious stones (see page 180). Uses. Powdered corundum is used as a polishing powder. Emery, an impure variety containing iron is used, as a polishing pow- der and in making abrasive wheels (emery wheels). Occurrence. Corundum occurs in crystalline limestones and metamorphic rocks (gneiss, schists, slates, etc.). It occurs at various places in the Appalachian Mountain region ; emery is mined at Chester, Mass., and corundum at Laurel Creek, Georgia; Corundum Hill, N. C. ; at Salida, Colo., it occurs in a quartz vein in gneiss. In 1898 4,072 tons of corundum and emery were produced in the United States, valued at about $253,630. The imports of emery in the United States in 1898 were valued at $133,399. Corundum was discovered in Canada in 1896. Garnet.* (Seepage 180.) Hardness usually 6.5 to 7.5, sometimes nearly 8. Crushed garnet used in preparing abrasive paper and belts for various kinds of high polishing, especially leather in boot and shoe factories. * Mineral Industry, VI, 11-26. t Preliminary report on the corundum deposits of Georgia. By Francis P. King. Georgia Geol. Survey, Bui. II. Atlanta, 1894. (Contains bibliography.) Corundum in the Appalachian crystalline belt. By J. V. Lewis. Trans. Amer. Inst. Min. Eng., 1895, XXV, 852-906. New York, 1896. (Contains bibliography.) Mineral Industry, VII, 15-21. Corundum in Ontario. By A. Blue. Trans. Amer. Inst. Min. Eng., 1898, XXVIII, 565-578. On the origin of corundum associated with the peridotites of North Carolina. By J. H. Pratt. Amer. Jour. Sci., 1898, CLVI, 49-65. Corundum mining in North Carolina. Eng. and Min. Jour., April 23, 1898, LXV, 490. Corundum and its uses. Nature, April 13, 1899, LIX, 558-559. Emery, etc., in the Villayet of Aidin, Asia Minor. By W. F. A. Thomse. Trans. Amer. Inst. Min. Eng., 1898, XXVIII, 208-825. t Garnet as an abrasive material. By F. C. Hooper. School of Mines Quarterly, Jan., 1895, pp. 124-127. New York. U) , C, 266 ABRASIVES. Garnet for abrasive purposes mined in the Adirondack Mountains is of superior hardness ; it occurs in pockets in hornblende-feldspar. Pro- duct in 1892 about 2,000 tons. Sand.* The principal use of sand as an abrasive is in connection with gang- saws in sawing marble, limestone, and other stones. Pumice, t Pumice is a very porous light lava, used in polishing various sub- stances ; most of the pumice of commerce comes from Mt. Vesuvius and the Lipari Islands. Tripoli. Tripoli is fine grained infusorial earth, composed of the siliceous skel - etons of microscopic animals and plants. Uses. As a polishing powder. Its grains must be small enough to produce 110 perceptible scratch on the surface being polished. As an absorbent for nitroglycerin. In blocks for blotters. Distribution and occurrence. Tripoli is found in the United States in Virginia near Eichmond ; in California near Monterey, and at Crow's Landing, Stanislaus county; in Nevada. In Newton county, Missouri, a deposit of siliceous limestone from which the lime has been leached is called tripoli. Deposits of siliceous powder found in Arkansas. Tripoli is limited to no particular geologic horizon. Whetstones. i Most whetstones are varieties of sandstone, schist, or novaculite, with silica as the abrasive element; of sedimentary origin. Their abrasive powers depend largely upon the size and sharpness of the grit grains. * Carborundum, crushed steel, and chilled iron shot, artificial products, are largely used as abrasives, for purposes similar to those of corundum, sand, etc. t South Italian volcanoes. Ed. by H. J. Johnston, pp. 67-71. Naples, 1891. I Whetstones and the novaculites of Arkansas. By L. S. Griswold. Geol. Survey of Arkansas for 1890, III. Little Rock, 1892. The whetstones and grindstones of Indiana. By E. M. Kindle. Twentieth ann. rep. Geol. and Nat. Hist, Survey of Indiana, 1895; pp. 329-368. Indianapolis, 1896. 268 ABRASIVES. Properties of whetstones. Effect of coarse-grained and of fine-grained stones upon tools. Uniformity in size and distribution of grains essential. Effect of foreign matter between grains. Compactness of the stone due to the particles being cemented, or to their being jammed together with or without cementing matter. Character of grains. In sandstones : irregular rough grains. In schists: irregular massive, or minute angular grains. Wear of whetstones. Should be faster in stone than in metal, to prevent glazing. Glazing is due to wearing away or dulling of the cutting points, clog- ging of spaces between the points, or both. Hard fine grained stones most apt to glaze. Fast wearing stone. Slow wearing stone. Oilstones so called because oil is used to float away the abraded metal. They are very fine grained. Scythe-stones may be used dry. Water is sufficient to carry away the metal from coarse-grained stones. Varieties of whetstones. Sandstones furnish most of the whetstones of the United States. Labrador stone from Cortland county, New York. Hindostan stone from Indiana.* Adamscobite stone from Pierce City, Mo. Schists furnish scythe-stones especially. Whetslates. Novaculites. The novaculites of Arkansas furnish the finest oilstones and honestones in the world. The Turkey stone. Whetstones of the United States. Arkansas, Indiana, Vermont, and New Hampshire furnish most of the whetstones of the United States. The Arkansas stone (novaculites): exceedingly hard; adapted to grinding fine-edged tools of all sorts. The " Arkansas stone." The " Ouachita stone." Indiana. Oilstones obtained from Orange county ; very fine grained sand- stone of Carboniferous age. * At an Indiana whetstone quarry. By O. C. Salyards. Stone, 1896, XIII, 539-543. 270 ABRASIVES. Vermont. Whetstones and scythe-stones ; principally mica schists of Cam- brian and Huronian ages. New Hampshire. Scythe-stones and other whetstones from Grafton county ; mica schists of Huronian and Silurian ages. Other states. New York produces Labrador stone, a fine grained green sand- stone, in Cortland county. Missouri produces Adamscobite stone at Pierce City. Ohio (Berea, Cuyahoga county), and Michigan (Grindstone City, Huron county), furnish sandstone scythe-stones. Statistics. Grindstones. Grindstones are made from sharp-grained compact sandstones ; grains should be of uniform size, and the stone should be soft enough to wear without glazing. Most of the grindstones of the United States are produced in Ohio, Michigan, South Dakota, and California. Other states supply stones for local demands. Ohio. Grindstones are quarried in northern part of state from Berea Grit (Lower Carboniferous). Cuyahoga, Lorain, and Summit coun- ties are the principal producers; there are also quarries in Stark and Washington counties. Michigan. Great grindstone quarries at Grindstone City, 90 miles north of Port Huron ; fine-grained sandstone free from foreign matter. Statistics. Millstones. Millstones are not properly abrasives. They are made from hard, sharp-grained, tough rocks, of coarse texture. Conglomerates are fre- quently used. Millstones in the United States are produced principally in New York, Pennsylvania, Virginia, and Ohio. Buhrstone is a quartz rock with an open cellular structure especially adapted to the manufacture of millstones. Best qualities of buhr- stones come from the Paris basin (Tertiary). Somewhat similar stones occur in Alabama, Georgia, and South Carolina. 272 ABRASIVES. Uses. In grinding grain. Crushing other materials. Effect of the roller process in manufacture of flour on use of mill- stones. 274 MARBLE. MARBLE.* " Any limestone, whether compact, crystalline, or granular, which will receive a polish and is suitable for ornamental purposes, is considered a marble." Uses. The various uses of ordinary limestone. Monumental and decorative interior work ; statuary. Adaptations of special colors and varieties. Origin and occurrence. Marbles are mostly metamorphosed limestones, and originated as or- ganic sedimentary beds. Forms, structural disturbances, and changes of the beds. Kinds of marble. Marbles vary from mottled impure limestone to the finest and most highly crystalline white varieties ; from white through all mot- tled and variegated colors to black. Statuary marble must have a perfectly uniform color and be free from flaws; rare. Parian marble the finest statuary marble; supply about exhausted. Pentelican marble much used by the ancients. Cararra marble, from the Apennines, used almost entirely by sculptors at present. Color snow-white ; texture saccharoidal. Marbles of all kinds, mottled, banded, or of uniform color, are used for ordinary interior decorations. Light tints most used ; black marble rare. "Onyx" marble, a crystalline cave deposit; its beauty and scarcity.! Distribution. Marble has a very general distribution, both geologic and geographic. Foreign marble (principal producers) : Austria, Belgium, France, Italy, Spain, Portugal. These countries all rich in marbles. The Italian marbles from the Apennines, used for sculpturing, are the most noted. * Report on the building stones of the United States. Tenth census, 1880, X, 1-393, with plates. Stones for building and decoration. By George P. Merrill. Pp. 83-166. New York, 1891. The building and ornamental stones of Great Britain and foreign countries. By Ed- ward Hull. London, 1872. t The onyx-marbles. By Courtenay De Kalb. Stone, Nov., 1898, XVII, 397-405. Trans. Amer. Inst. Min. Eng., 1895, XXV, 557. The onyx deposits of Barren county, Kentucky. By S. S. Gorby. Eng. and Min. Jour., June 17, 1899, LXVII, 707-708. 276 MAKBLE. Mexico. A large deposit of marble, called " Mexican onyx " ; this de- posit practically exhausted; most of "Mexican onyx" from other sources. Marble of the United States. The principal producing states are : Vermont:* marble "white, clouded, or blue." Principal quarries at Rutland. Tennessee :t marble variegated; of Lower Silurian age; extensive quarries of colored marble. Georgia:! the same marble as that of Tennessee. New York. The largest quarries are at Gouveneur, where the "St. Law- rence" marble is quarried. Production of marble in 1897. 1898. 1899. Vermont $2,050,229 Georgia 598,076 Tennessee 441,954 New York 354,631 Maryland 130,000 Colorado 99,600 Massachusetts... 79,721 Pennsylvania . . . 62,683 California 48,690 Arkansas|| marble the same as Tennessee and Georgia. Extent of the Arkansas marbles; not now worked. * Geology of Vermont. By A. D. Hager. II, 751-780. Claremoiit, N. H., 1861. t Geology of Tennessee. By James M. Safford. Nashville, 1869. t A preliminary report on the marbles of Georgia. By S. W. McCallie. Geol. Survey of Georgia, Bui. no. 1. Atlanta, 1894. g Building stone in the State of New York. By J. C. Smock. Bui. no. 3, New York State Museum of Nat. Hist. Albany, 1888. Building stone in New York. By J. C. Smock. Bui. of the New York State Museum, II, no. 10. Albany, 1890. II Marbles and other limestones. By T. C. Hopkins. Ann. rep. Geol. Survey of Arkansas for 1890, IV. Little Rock, 1893. Fig. 134. The value of the marble quarried in the United States since 1885. 278 LIMESTONES OTHER THAN MARBLES. LIMESTONES OTHER THAN MARBLES.* Limestone is a sedimentary rock ; it is composed of calcium carbonate, often with magnesium carbonate ; it always contains impurities. Uses. For building purposes. Importance as a building stone. Crushing strength per sq. in. from 62 samples, 14,545 Ibs., rang- ing from about 5,000 Ibs. to 25,000 Ibs. As a flux in smelting ores. Lithographing. Lime; cement. Carbonic acid gas (marble usually used). Whiting (from chalk). Effect of limestone on the mineral and agricultural wealth of a country. Origin. Organic. Kinds of organisms : rhizopods, pteropods, and heteropods (deep sea); corals, echinoderms, crustaceans, bryozoans, brachi- opods, lamellibranchs, gasteropods, cephalopods (off shore or comparatively shallow water) ; calcareous algae. Chemical. Methods of formation. Occurrence and distribution. Of sedimentary origin, subject to laws of sedimentary rocks. Universal geographic and geologic distribution. Approximate thickness of limestone formations. Varieties. Through all grades from calcareous shales and sandstones to pure limestones. Shaly limestones; sandy limestones. Crystalline limestones (mostly marbles). Chalk. Oolitic limestones (Ex. Bedford stone). * Report on the building stones of the United States. Tenth census, 1880, X, 1-393, with plates. Stones for building and decoration. By George P. Merrill. Pp. 122-166. New York, 1891. Marbles and other limestones. By T. C. Hopkins. Geol. Survey of Arkansas for 1890, IV. Little Book, 1893. . 280 LIMESTONES OTHER THAN MARBLES. Lithographic limestone. Dolomitic limestone.* Dolomite is a carbonate of calcium and magnesium, with the propor- tions varying 1 to 1, 1 to 3, or 1 to 5. Hydraulic limestone. Prevalent colors in limestones. Blue, gray, buff, white, the most common. Alteration of colors by weathering. Principal limestone-producing states. Pennsylvania: Lower Silurian, Devonian, and Lower Carboniferous limestones ; used largely for building, and as a flux in smelting. Indiana: the "Bedford oolitic stone "t (Lower Carboniferous) the most important in the state. Principal quarries in Lawrence and Monroe counties. Ohio: Silurian, Devonian, Carboniferous stone; dull in color; quar- ried in various parts of the state ; used mostly for rough work. Illinois : largest quarries in Will county (at Lemont and Joliet) ; Nia- gara group; stone light drab, fine grained; Trenton limestone of Jo Daviess county also important. Production of limestone in 1897. 1898. 1899. Pennsylvania $2,327,870 Indiana 2,012,608 Ohio 1,486,550 Illinois 1,483,157 Missouri 1,018,202 Other states 6,494,274 Lithographic Limestone. Character of lithographic stone. It must contain no grains or crystals. Distribution. The lithographic limestone of commerce is produced at Solenhofen, Bavaria; it is of Upper Jurassic age. Lithographic limestone found, but not proved commercially important, in Alabama, Arizona, Arkansas, Illinois, Indiana, Iowa, Ken- tucky, Missouri, Tennessee, Texas. Utah, Virginia. * The origin of dolomite. Amer. Jour. Sci., May, 1895, CXLIX, 426-427. Origin of the dolomites. By Hall and Sardeson. Bui. Geol. Soc. of America, 1894, VI, 193-198. tThe Bedford oSlitic limestone of Indiana. By T. C. Hopkins and C. E. Siebenthal. Twenty-first ann. rep. Geol. Survey of Indiana, 1896, pp. 290-427. 282 LIMESTONES OTHER THAN MARBLES. Lime. The importance of lime. Lime (CaO) is made by driving off the carbonic acid (C0 2 ) from lime- stone. Uses. In making mortar and cements. Plastering, whitewashing. As a fertilizer. Value of lime as a fertilizer; its effect upon soil. As a disinfectant. Uses in chemistry. Kinds of lime. Common limes. Hydraulic limes. Characteristics of lime. Slaking. Rehardening (setting) with foreign substances. Sand in mortar furnishes points on which the lime crystallizes in setting. Lime can be produced in any locality that has limestone. Importance of lime in engineering works. Hydraulic Limestone.* Hydraulic limestone contains clay and furnishes a lime that will set under water. The hydraulic limestones of the United States are usually shaly and contain considerable magnesia. Used for making hydraulic lime and cement. ANALYSES. Rosendale, N. Y.t New York. Wisconsin. Magnesia carbonate 23.92 25.94 29.19 Silica : 22. 14 15.37 17.56 Alumina ) on f Iron oxide N 3 ' 80 " ( 9.13 2.25 1.40 2.24 Water and organic matter 1 .83 1.20 * On limes, hydraulic cements, and mortars. By Q. A. Qillmore. Ninth edition. New York, 1888. t Mineral industry for 1894, III, 91. 284 LIMESTONES OTHER THAN MARBLES. Distribution. Geologic. Most of the hydraulic limestone of the United States occurs in Paleozoic rocks. Geographic. Hydraulic limestone is by no means so widespread as ordinary limestone. The principal states in which it occurs and is utilized are New York, Indiana, and Kentucky (Louisville region), Pennsylvania, Wisconsin, and Illinois. Hydraulic cement. Hydraulic cement is made from hydraulic limestone; it has the power of setting under water. Composition. How made.* Uses and importance. The principal manufacturing district is Rosendale, Ulster county, New York. The industry was established there in 1823. The output of the Rosendale district in 1848 was 190,000 barrels, worth $260,000; in 1898 it was 3,245,225 barrels, worth $2,103,554. The district next in importance is that of Kentucky and Indiana, in the vicinity of Louisville. Its output in 1898 was 1,929,018 barrels, worth $482,254. Chalk, t Chalk is an earthy, white limestone, for the most part composed of the skeletons of minute organisms. Mode of formation. Uses. For making whiting. For crayons. In the manufacture of Portland cement.* In fertilizing. *The manufacture of Rosendale cement. Eng. and Min. Jour., Oct. 16, 1897, LXIV, 459. t The Neozoic geology of southwestern Arkansas. By R. T. Hill. Geol. Survey of Ark. for 1888, II, 153-162. Little Rock, 1888. The Niobrara chalk. By Samuel Calvin. American Geologist, Sept., 1894, XIV, 14O-161. I Portland cement; its manufacture, testing, and use. By D. B. Butler. London and New York, 1899; 360 pages. The science and art of the manufacture of Portland cement, with observations on some of its constructive applications. By Henry Reid. New York, 1877. On the manufacture of Portland cement. By John C. Branner. Geol. Survey of Ark. for 1888, II, 291-303. Portland cement. A monograph. By C. D. Jameson. Iowa City, 1895. Portland cement. By S. B. Newberry. Seventeenth ann. rep. U. S. Geol. Survey, pt. Ill, 881-893. Washington, 1896. American cements. By D. Cummings. Boston, 1898. 286 LIMESTONES OTHER THAN MARBLES. Distribution. Geographic. England and France are the principal producers of chalk. Deposits of chalk are found in the United States in Arkansas, Texas, Iowa, and Nebraska. Portland cement is a hydraulic cement, made from carbonate of lime (chalk) and clay. "Not over thirty or forty per cent of ordinary Portland cement which is active in the hardening process. The rest is inert and like so much sand."* Methods of manufacture, t Sixty per cent of silica required in the clay, magnesia limit 3%. The cement yield is about 60% of the weight of the chalk and clay. Uses of Portland cement. In mortar, for cementing building stones, for paving purposes. Artificial stone for building purposes. Advantages of Portland cement. Gyp sum. i Gypsum is a soft hydrous sulphate of calcium, varying in color- white, red, yellow, brown, blue, black. Uses. In manufacture of " plaster of Paris, " and cement plasters.il As "land plaster." In statuary (alabaster). Varieties. Selenite. Fibrous gypsum (satin spar). Alabaster. ' Modes of occurrence. Usually dull colored ; mixed with impurities ; in beds often of great thickness, interstratified with limestones, clays, and salt. Origin : deposited from solution. * J. B. Johnson.. Proc. Amer. Assoc. for Adv. of Sci., 1898, XL, VII, 244. t History of the Portland cement industry in the United States. By Robert W. Lesley. Jour. Frank. Inst., Nov., 1898, CXLVI, 324-318. t Geology and mineral resources of Kansas. By Robert Hay. Pp. 46-48. Topeka, 1893. Mineralogy of New York. By Lewis C. Beck. Pp. 61-67. Albany, 1842. I Journal Frank. Inst., February, 1899, CXLVII, 171. II The technology of cement plaster. By P. Wilkinson. Eng. and Min. Jour., Nov. 12, Report on gypsum and gypsum cement plasters. By G. P. Grimsley and E. H. S. Bailey. Univ. Geol. Survey of Kansas, V. Topeka, 1899. - . ^K i3*~~e~ . ^c_. ^ ^ , / 2<^ / >^ -^ f ?v(* -V ?/> 288 LIMESTONES OTHER THAN MARBLES. Distribution. Gypsum is widespread, geographically as well as geologically. Its distribution in the United States is fairly well shown by the fol- lowing statistics.* Principal gypsum-producing states in 1897. 1898. 1899. Short tons. ** Michigan .......... 94,874 Iowa ............ | Kansas .......... \ 83 ' 783 New York ......... 33,440 Texas ............. 24,454 12,309 Indian lerritory.) South Dakota ...... 8,350 Virginia ........... 6,374 It is quarried somewhat in other states. The total product of the United States in 1897 was 288,982 tons, worth $755,864. * The salt and gypsum industries in New York. By F. J. H. Merrill. Bui. New York State Museum, III, no. 11. Albany, 1893. Gypsum in Arizona. By W. P. Blake. Amer. Geologist, Dec., 1896, XVIII, 394. The origin and age of the gypsum deposits of Kansas. By G. P. Grimsley. American Geologist, Oct., 1896, XVIII, 236. Gypsum in Kansas. By G. P. Grimsley. Kansas Univ. Quarterly, 1897, VI, 15-27. Gypsum in Iowa. By C. R. Keyes. Mineral Industry, 1895, IV, 377-388. UNITED STATES KANSAS . MICHIGAN . NEW YORK. IOWA- US. IMPORTS. Fig. I3a. The production and imports of gypsum in the United States since 1880. 290 BUILDING STONES IN GENEEAL. BUILDING STONES IN GENERAL.* Few kinds of stone cannot be used for building ; those most used are granites, sandstones, and limestones. Properties to be considered in building stones. Ability to withstand weather, t Ability to withstand heat. Color. Hardness before and after being worked. Density. Crushing strength. Building stones are seldom subjected to more than from one-sixth to one-tenth the pressure they can withstand. Stone subjected to a gradual pressure can withstand more than the same stone subjected to sudden pressure. CRUSHING STRENGTH (LBS. PER SQ. IN.) OF SOME BUILDING STONES. Granite. East St. Cloud, Minn.. Mystic River, Conn... . / 28,000 \ 26,250 1 18,125 122,250 FourcheMt.. Ark. (Seyenite) a3,620 Cape Ann, Mass 19,500 Vinalhaven, Maine 15,698 Penryn, Cal 6,117 Average of 72 samples 17,591 Average of 37 Wisconsin f . >R ,,, granites and rhyolites. . ( <50 -' > * a Bedford, Indiana., j Conshohocken, Pa. Joliet, Illinois.... Bloomington, Ind. Ellettsville, Ind.. Quincy. Illinois .. Average of 62 samples Average of 31 ( in Wisconsin] / 6,500 Sandstone. 16,340 14,775 i:!,75n 13.5m 9,787 14,545 25,102 Belleville, N. J Albion, N. Y. . . Middleton. Cor Berea, Ohio. . . . Vermillion, O. .. Portland, Conn. . Average of 100 samples Avg. 45 in Wis.I f 11,700 ( 10,250 *13,500 f 6,950 t 5,550 10,250 7,840 4,945 9.046 6,427 Distribution. Stone that may be utilized for building occurs in all countries, and in almost all geologic formations. * Steinbruchindustrie und Steinbruchgeologie. Technische Geologic nebst prakti- schen Winken fur die Verwertung Gesteinen. Von Dr. O. Herrmann. Berlin, 1899. The physical, chemical, and economic properties of building stones. By G. P. Merrill. Special publication Maryland Geol. Survey, II, pt. II. Baltimore, 1898. The collection of building and ornamental stones in the U. S. Nat. Museum. By G. P. Merrill. Smithsonian rep., 1886, pt. II, 277-648. Washington, 1889. Report on the building stones of the United States. Tenth census, 1880, X, 1-393, with colored plates. Washington, 1880. Stones for building and decoration. By George P. Merrill. New York, 1891. Stone. An illustrated magazine, issued monthly. Chicago, Illinois. t The decay of the building stones of New York city. By A. A. Julien. Trans. N. Y Acad. Sci., 1883, II, 67-79, 120-138. Durability of building stones. By H. A. Cutting. Amer. Jour. Sci., 1881, CXXI, 410. J On the building and ornamental stones of Wisconsin. By E. R. Buckley. Pp. 390-394. Madison, 1898. 292 BUILDING STONES IN GENERAL. Granite. Granite (average 8p. gr. 2.66) is a highly crystalline rock, varying widely in texture and color, with quartz and feldspar as essential constitu- ents; mica and hornblende with other minerals are usually present. Uses. In massive structures. As an ornamental stone: monuments; interior decorations. Damage done granite buildings by fire. Varieties. - Biotite granite; muscovite granite; hornblende granite, etc. Geologic relations. Granites may be of any age. They occur massive, never stratified; often as cores of mountain ranges ; sometimes as dikes. Distribution. Granite has a general distribution. It is the fundamental rock of the earth's crust. The New England States are the principal granite producers of the Union. Maine: granites gray (largely), pink, and red. Largest quarries at Vinalhaven. Massachusetts : Quincy quarries the most important ; stone coarse grained, usually dark blue-gray. Rhode Island : principal quarries near Westerly ; biotite granites, fine grained ; color, pink to light gray. Connecticut: granite and gneiss, fine grained; color, mostly light gray. Used locally. New Hampshire: granite in eastern part of state; color, light gray, white ; fine grained. " The muscovite-biotite granite of West Concord." California :* granite very generally distributed through the state. Quarries at Rocklin and Penryn. Stone fine grained : color, "light to dark gray." Quarries near Raymond and elsewhere in the state. Georgia : light-gray granite near Atlanta. Granite is quarried in many other states, but to a less extent. * Folio 5. Sacramento folio, California. Geologic Atlas of the United States. By the U. S. Geol. Survey. Washington, 1894. UttJU*, 294 BUILDING STONES IN GENERAL Value of production Massachusetts Maine Vermont New Hampshire Rhode Islan.1 . Connecticut New Jersey Georgia New York Pennsylvania Delaware Maryland California Other states . in 1897. $1,736,069 1,115,327 1,074,300 641,691 629,564 616,215 561,782 436,000 422,216 349,947 272,469 247,948 167,518 634,029 1898. 1899. Limestones. ^ See pp. 274-276, " Marble," and pp. 278-288, " Limestones other th marbles." i;in Sandstones. Sandstones are fragmental sedimentary rocks occurring in all geologic formations, having quartz-sand as an essential constituent; in color they vary from white to blue, brown, and red; color and adaptability deter- mined largely by cementing material. Freshly quarried sandstone usually soft, owing to the water contained. Varieties. Quartzites. Flagstones. Freestones. Calcareous sandstones; ferruginous sandstones. Other varieties. Geologic relations, Of sedimentary origin, subject to the conditions of other sedimentary deposits. Sandstone in the United States. Sandstone suitable for building is widely distributed. Ohio : most important quarries in the Berea Grit (Lower Carbonifer- ous) in northern part of the state. Stone fine grained ; color, buff to blue. 296 BUILDING STONES IN GENERAL. Pennsylvania: Triassic sandstone.* Principal quarries in Dauphin county. Color, "deep bluish-brown, slightly purple, " with red- dish-brown layers. Sandstone of importance in the Trenton formation. Connecticut: Triassic sandstone, brown and red. Quarries at Port- land most important. New York:f Cambrian sandstone (Potsdam); color, very light to light red; very hard. Upper Silurian (Medina) sandstone; gray to red; rather coarse texture. Devonian (Hamilton) sandstone; color, "dark blue-gray"; com- pact, fine grained. New Jersey : Triassic sandstone ; red and dark brown. Other states. Value of product in .1897. 1898. 1899. Ohio $1,600,058 New York 544,514 Pennsylvania 380,813 Connecticut 364,604 Massachusetts 194,684 New Jersey 190,976 Other states . . 789,796 Other Building Stones. Conglomerates: coarse grains or pebbles, held together by some cementing material; breccias are conglomerates in which the fragments are angular. Slates :{ metamorphosed clay shale, usually of some dark color; largely used in roofing. Other uses: tiles, school slates, blackboards, mantels, flagging, bil- liard tables. Usually found in regions of folded rocks. Tuff: consolidated and unconsolidated volcanic rocks are sometimes used in buildings. Extensively used on the Santa Fe route for railway ballast. * Building materials of Pennsylvania. I, Brownstones. By T. C. Hopkins. Appendix to ann. rep. Pennsylvania State College for 1890. t Building stone in the State of New York. By J. C. Smock. Bui. of the New York State Museum, no. 3. Albany, 1888. Building stone in New York. By J. C. Smock. Bui. of the New York State Museum, II, no. 10. Albany, 1890. J The slate regions of Pennsylvania. By Mansfield Merriman. Stone, July, 1898, XVII, 77-90. The strength and weathering qualities of roofing slates. By M. Merriman. Trans. Amer. Soc. Civil Eng., 1892, XXVII, 332-349; 1894, XXXII, 529-543. The New York slate industry. By J. N. Nevins. Eng. and Min. Journal, May, 1899, LXVII, 587-588, 622. ? 6- 298 BUILDING STONES IN GENERAL. Gneiss: composition same as granite, but it shows a foliated or banded structure; it is extensively used in buildings in Brazil. Schists: structure similar to that of gneiss; with little or no feldspar. The schists split readily ; much used for flagging, and sometimes in foundations. Syenite: like granite, except that it contains no quartz. The syenite near Little Rock, Arkansas, an excellent building stone, is blue or gray in color. Average crushing strength (per sq. inch in 2-inch cubes) 33,620. Used in buildings and paving.* Augite: a dark-colored eruptive rock, usually containing magnesium and iron. It is used some for buildings, and extensively in paving. Serpentine: a hydrous silicate of magnesia, probably derived from altera- tion of eruptive rocks; color usually green or yellowish, sometimes brown, red, or almost black; variety known as verde-antique much used for interior decoration. Its softness makes serpentine objectionable for decorations. * The igneous rocks of Arkansas. By J. Francis Williams. Ann. rep. Geol. Survey of Arkansas for 1890, II, 42-53. Little Rock, 1891. 300 KAOLIN. Kaolin is mostly kaolinite, a hydrous silicate of alumina, containing silica 46.5/ , alumina 39.5/o> water 14.0/ . Kaolin always contains other substances as impurities. Varieties of kaolin with water varying from 7.49/ in rectorite to 24.46% in newtonite. Uses* The finest grades for making fine porcelain and chinaware. Kaolin from near St. Yrieix, France, used for the Limoges and Sevre porcelain. The common grades for cream-colored ware, sanitary ware, and other ordinary grades of pottery, and for decorative tiles. Origin. Kaolin is formed by decomposition from aluminous minerals, especially from the feldspars. Composition of feldspar. Changes necessary to produce kaolin. Experiments of Daubree on pulverized feldspar. Occurrence. 1. In irregular beds in decayed granites, porphyries, and gneisses. Quarries near St. Yrieix, France. Formerly mined at Brandy wine Summit, Pa.t Quarrying and mining methods. Original deposits to be sought only in rocks whose decay would furnish kaolin. 2. In regular sedimentary beds by the removal and deposition in water of original deposits. Examples of Arkansas kaolins. Conditions under which sedimentary kaolins may be formed. Determination of sedimentary kaolin. Kaolin may occur in rocks of any geologic age, and in any part of the world containing rocks capable of forming it upon decay. Kaolin; its occurrence, technology, and trade. By T. C. Hopkins. Mineral Industry for 1898, VII, 148-160. Trait6 des arts ce>amiques. Par A. Brongniart. Paris, 1854. Handbuch der gesammten Thonwaarenindustrie. Von Bruno Kerl. Braunschweig, 1879. For lists of books on pottery, see Bibliographic C6ramique. Par Champfleury. Paris, 1881. Bibliography of clays and the ceramic arts. By J. C. Branner. Bui. 143, U. S. Geol. Survey. Washington, 1896. t On Pennsylvania kaolin deposits. By J. P. Lesley. Ann. rep. Geol. Survey of Penn- sylvania for 1885, pp. 571-614. Harrisburg, 1886. 302 Treatment. Practically no kaolin is now used as it comes from the ground. Hand picking; grinding; settling; addition of "flint" or quartz and feldspar. Effect of drying on different kaolins. Effect of burning. Loss of plasticity. Color and composition. Clay.* Clay is for the most part an impure kaolin, formed originally in the same way. Examples of differences shown by analyses. Clays of organic origin. tfses.t Manufacture of common bricks, "vitrified" bricks for paving, tiles (drain and roof), terra cotta (ornamental and architectural), common pottery, door knobs, chimney pots, sewer pipes, and playing marbles. Refractory purposes. Occurrence. Residuary clays from the decomposition of rocks in place. Forms of deposits from decay along the outcrops of sedimentary rocks. Forms of deposits from the decay of crystalline rocks. Transported clays. Forms of the beds. Cause of areal changes in the characters of the beds. Why some beds are thick and others thin. Why some beds are hard and others soft. The loess clays of the Mississippi valley. The Milwaukee brick clays. Why the bricks are cream colored. Formation of slates. * Clay materials of the United States. By R. T. Hill. Mineral resources of the U. S. for 1891, pp. 474-528. t Annual reports of the National Brick Manufacturers' Association. Indianapolis, since 1887. The Clay Worker (Monthly). Indianapolis, since 1884. A practical treatise on the manufacture of bricks, tiles, terra-cotta. etc. By C. T. Davis. Philadelphia, 1889. , *+*** 9 -/ 75^>>txS--*C xt^-^tx*-^ __ e^o^" &".. T-T^K /r io4-jn, "t^of. F. 304 BAUXITE. Distribution. Clays are found in sedimentary rocks of all ages and in all countries. The clay industries of the United States. New Jersey :* Trenton potteries. Ohio : East Liverpool and Cincinnati potteries. Missouri : St. Louis brick industries. The value of the clay products of the United States since 1889 has been between nine and ten millions of dollars annually. BAUXITE. Bauxite is hydrate of alumina; essentially alumina 73.9, water 26.1%. It is massive, oolitic, or earthy; white, gray, or red. Manufacture of alum, sulphate of alumina, and aluminum, and as a refractory material or for increasing the refractoriness of fire- clays. Occurrence. In southern France in massive beds at the junction between Triassic and Jurassic; in Arkansas* as irregular masses in Tertiary rocks, sometimes covering several acres; in Alabama as beds interstratified with Paleozoic rocks. * Report on the clay deposits of New Jersey. By George H. Cook and J. C. Smock. Trenton, 1878. t Aluminium : its history, occurrences, properties, metallurgy, etc. By J. W. Richards. Philadelphia, 1890. I The bauxite deposits of Arkansas. By J. C. Branner. Journal of Geology, 1897, V, no. 3, pp. 263-289. (Bibliography.) 306 ALUMINUM. ALUMINUM.* Uses. Conductor of electricity. Manufacture of alloys. Aluminum-copper alloys. j,_> xywa '' Aluminum-iron alloys. Manufacture of articles requiring strength and lightness and of articles that should not corrode. The high price of aluminum prevented its general use until a few years ago. Metallic aluminium or aluminum does not occur in nature ; the metal has been known since 1827, but it is only since 1889 that the price of it has been below $2.00 per pound. It was formerly made from cry- olite; it is now made from bauxite. Cryolite (fluorine 54.4, aluminum 12.8, sodium 32.8) was formerly used in the manufacture of aluminum. The largest known deposits of cryolite are on the west coast of Green- land, 12 miles from Arksuk, where it occurs in a granite vein in gneiss. t Aluminum is now made from bauxite, t which is called aluminum ore. (See page 304.) Aluminum can be made from kaolin and common clays, but the cost of extraction from these substances is much greater than from bauxite. * Aluminium: its history, properties, etc. By J. W. Richards. Seconded. Philadel- phia, 1890; third ed., Philadelphia and London, 1896; 666 pages. The properties of aluminum, with some information relating to the metal. By A. E. Hunt, J. W. Langley, and C. M. Hale. Trans. Amer. Inst. Min. Eng., 1890, XVIII, t On the cryolite of Evigtok, Greenland. By J. W. Taylor. Proc. Geol. Soc. of London, 1856, XII, 140-144. t The preparation of alumina from bauxite. By James Sutherland. Eng. and Min. Journal, Oct. 3, 1896, LII, 320-322, A*y-vvi C^t-. f UNITED STATES GERMANY ti SWITZERLAND ffit! FRANCE E.NOLAND Fig 136 The aluminum output of the chief producers, and its market price per pound since 1889. GLASS-SAND. GLASS-SAND.* The essential constituent for manufacturning glass is silica; it is found as loose sand or as more or less compact sandstone. Purity of sand necessary. ANALYSES OF GLASS-SAND. Constituents Isle of Wight France Silica 97.0 98.8 Moisture Oxide of iron and magnesium 1.0 0.5 2.0 0.7 100.0 100.0 Distribution. Sand that may be used for making glass has a very general distribu- tion. England, France, Germany, Austria, Belgium, Holland, Sweden, and Canada are all rich in glass-sand. It may occur in rocks of any geologic age. Glass-sand of the United States. New Jersey has extensive deposits of Tertiary age.. Pennsylvania : Oriskany sandstone in Mifflin county. West Virginia : Oriskany sandstone in Morgan county. Indiana: Madison, Parke, Clark, and Harrison counties. Michigan : glass-sands from the shores of Lake Michigan. California : recent sands near Monterey. Wisconsin : glass made from the St. Peter's and the Potsdam sand- stone. Missouri : at Crystal Springs in Jefferson county. Iowa: Lower Silurian (St. Peter's sandstone). * Geol. of New Jersey, 1868, pp. 690-695, and 293. Newark, 1868. Geol. Survey of Missouri, 1855-1871, pp. 62, 129, 200, 273, 289, 302. Jefferson City, 1873. Geol. Survey of Missouri, 1872, p. 289. New York, 1873. Geol. and natural history of Indiana. Twelfth ann. rep., 1882, p. 22. Indianapolis, 1883. Geol. of Wisconsin, 1873-77, II, 290, 546, 558. Madison, 1877. Second Geol. Survey of Pennsylvania, 1888-89. Rep. F 3, pp. 271-274, 288-292. Harris- burg, 1891. Iowa Geol. Survey. First ann. rep. for 1892, 1, 24-25. Des Moines, 1893. Tenth census, 1880, II, 1029-1152. 310 REFRACTORY MATERIALS. REFRACTORY MATERIALS.* Refractory materials are substances of various compositions, capable of withstanding high temperatures without fusing. Uses. They are used for lining furnaces, stoves, and chimney backs, and making crucibles, hearths, retorts, and the like; clay of low refractoriness is used for making sewer pipes and " vitrified " paving bricks. Composition. (Some infusible substances are not mentioned here because they are not practically available.) Refractory materials vary greatly in composition. Aluminous: fire-clay, bauxite, kaolin. Magnesian: asbestos, magnesite, talc. Carbonaceous : graphite. Calcareous : pure lime. Siliceous: pure quartz of Dinas brick. The refractoriness of most substances depends upon their purity. Pure lime highly refractory alone ; a flux with certain other sub- stances. Magnesia refractory alone ; a flux in combination. Pure silica used for Dinas brick; lowers refractoriness of other substances. Fire-Clay .t Clays and kaolins are hydrous silicates of alumina. Fire-clays proper are clays that do not fuse readily. Fire-clays may occur with sedimentary rocks of any age. How deposited. Why so abundant in the Carboniferous. Structural features. Varying degrees of refractoriness. * Metallurgy. By John Percy. Refractory materials : crucibles, furnaces, fire-bricks, etc., pp. 87-154. London, 1875. Fuel and refractory materials. By A. Humboldt Sexton. London, 1896. t Determining the refractoriness of flre-clays. By H. O. Hofman and C. D. Demond. Trans. Amer. Inst. Min. Eng., 1894, XXIV, 42-66. Die feuerfesten Thone. Von Dr. Carl Bischof. Leipzig, 1876. 312 REFRACTORY MATERIALS. Refractoriness determined by composition and physical condition. Fluxing influence of the common constituents of clays on a silicate of alumina determined by Bischof. (20 of magnesia 28 of lime 31 of soda - - = | 40 of iron oxide (47 of potash. Bischof 's formula based on chemical composition is as follows: Refractoriness = M * g 8 . Q X 0.2759. [M = (0.6 X Fe-jO,) + (0.857 X CaO) + (1.2 X MgO) + (0.5092 X K 2 O) + (0.7729 X Na,O).] According to this formula fire-clay of Cheltenham, Mo., has re- fractoriness of 0.86; Stourbridge best clay, 1.28; clay for vitrified brick, 0.24 to 0.34. Wherein analyses of clays may not be trusted. The refractoriness of a single clay varies with physical condition. Use of "grog" or " chamotte." Increase of refractoriness of clay by the use of bauxite. Paving-brick made of fire-clay of low refractoriness. How to lower or raise refractoriness. Magnesite.* (Carbonate of magnesia: magnesia 47.6; carbon dioxide 52.4.) Uses. Refractory material in basic hearths of steel furnaces and fireproof buildings. Bleaching agent in making wood-pulp paper. Manufacture of magnesium salts. Manufacture of carbonic acid for artificial mineral waters. Occurrence and distribution. Associated with serpentines, talcose schists, and other magnesian rocks, in thin veins and strings. Mined near Veitsch, Austria, and made into fire-brick. At Bolton, Canada, deposit said to be 60' thick. In Silesia, Germany, deposits at Grochau and Baumgarten. In Greece as veins in serpentine. * A history and description of magnesia, and its base and compounds. By Henry G. Hanks. San Francisco, 1895. Magnesite in India. Eng. and Min. Journal. Dec. 3, 1898, LXVI, 669. 314 REFRACTORY MATERIALS. In United States associated with serpentine beds on Staten Island ; in California in Fresno, Alameda, Napa, Santa Clara, San Mateo, and other counties. It can probably be found as white veins in serpentine wherever the latter occurs. It is worked only in California. The California output in 1898 was 1,263 tons, worth $19,075. In January, 1900, crude German magnesite was worth $12.00 per ton and magnesite bricks $185.00 a thousand in New York. Chrysotile ( "Asbestos " ).* Commercial "asbestos " is chrysotile, a fibrous variety of serpentine. Silica 44.1, magnesia 43.0, water 12.9. Uses. Steam packing; covering for boilers, steam pipes, hot-water pipes; fireproofing buildings and safes; gas stoves and fireplaces, fire- proof cloth (theatre curtains) ; weighting silks. Distribution and occurrence. It occurs in narrow veins in serpentine rocks; the veins but few inches wide ; fibers cross the veins. Method of mining. Nearly all the asbestos used in the United States comes from Quebec, Canada, which produces 85% of the world's supply. California produced 10 tons in 1898, as against 1,200 tons in 1882 and 100 tons in 1888. The imports of asbestos, including manufactured articles, were valued at $3,221 in 1877; at $140,845 in 1887; and at $268,264 in 1897. Imports of asbestos into the United States from Canada : 1870 $ 7 1898 $ 1880 9,736 1899 1890 257,879 1900 1897 190,971 1901... Talc.t Talc is also known as soapstone and steatite; its composition: silica 63.5, magnesia 31.7, water 4.8. >. * The mining industries of eastern Quebec. By R. W. Ells. Trans. Amer. Inst. Min. Eng., 1889-90, XVIII, 320-328. Notes on asbestos and asbestlfonn minerals. By G. P. Merrill. Proc. U. S. National Museum, 1895, XVIII, 281-292. Washington, 1896. t Genesis of the talc deposits of St. Lawrence county. By C. H. Smyth, Jr. School of Mines Quarterly, July, 1896, XVII, 333. (References.) /Talc and soapstone. By C. A. Waldo. The Mineral Industry, 1893, II, 603-^06. / Report on the talc industry of St. Lawrence county. By C. H. Smyth, Jr. Fifteenth ann. rep. State Geologist [of New York] for 1895, pp. 661-671. Albany, 1897. - 1L 316 REFRACTORY MATERIALS. It is used for cooking utensils, heating stoves, furnace linings, for fire- proof paints, adulterating soap. Fibrous talc is used for weight- ing paper, in paints, and for making wall plasters. It occurs in large beds, usually in regions of metamorphic rocks. St. Lawrence county, N. Y., principal producer of talc. Mined at Talcville in 400' shafts; vein 18-20', with granite walls. The output of fibrous talc in 1897 was 57,009 tons, worth $396,936. Graphite. (For geology of graphite, see pp. 200-202.) Theoretically graphite is pure carbon, but analyses of a large number of samples show it to contain at most from 80 to 99% carbon. Used for making crucibles ; mixed with clay and turned on a wheel like pottery; */>-' T; fr Lime. (For geology of limestone, see p. 278.) Lime alone " is one of the most refractory substances known, and no temperature has as yet been attained which has caused it to exhibit the slightest indication of fusion." Percy, 134. Crucibles made of unslacked lime are made by sawing the lumps in blocks and boring cavities in center. Silica. The Dinas fire-brick made of quartz-sand (96.73-98.31/ pure silica) from the Millstone Grit, in the Vale of Neath, near Swansea, Wales. They expand on being heated; fire-clay bricks contract. Silica bricks cannot be used where the slag contains metallic oxides. Any pure quartz may be used to manufacture silica bricks. Fire-clay is used to hold the sand together. Styrian silica bricks. Availability of novaculites. Occurrence and distribution of novaculites. Chrome Iron;* -< ^ Chrome iron has lately come into use for furnace linings. It is crushed, washed, and made into bricks for this purpose. * Engineering and Mining Journal, Feb. 6, 1897, LXIII, 136. " ^ ^..r^j,.^. X'-'i/v^ X-VT- /'ry. . L VA< ,^-tr vU*s~. ^ -~ 318 KEFRACTORY MATERIALS. Mica.* Uses. The large sheets of mica are used for stove and furnace doors ; covers for the eyes of persons working at certain trades. Scrap mica is ground up and used for insulating and fireproofing, and for a lubricant; also for an absorbent of nitroglycerin, in wall- paper, and in the manufacture of bronze powder. , 3'<~- --> vv^kXiw* /U~~-/W^> xn'vx jd*v^'J- xv-^^Av^, Composition and character. The mica of commerce is Muscovite, and has the following theoretical composition: Silica 45.2, alumina 38.5, potash 11.8, water 4.5%. Its transparency and flexibility. Occurrence. Mica occurs of commercial importance in the Appalachian Mountains in New Hampshire, Virginia, and North Carolina ; in the Black Hills of South Dakota ; in northern New Mexico and western Idaho. Found in pegmatite dikes in Archean gneisses and granites, generally cutting across the schistosity of the rocks. "Books" or crystals are scattered through the mass, though some- times near the walls. Usually less than 1% of mica in the rock; sometimes as high as 10%. Of the mined mica only from 1 to 10% is valuable as sheet mica. The mica imported into this country comes chiefly from Great Britain, Canada, and the East Indies. In January, 1900, the price of mica in New York was for sheets 1>X3 in., 60 cents, and sheets 8X10 in., $13.00 per pound. The value of the mica produced in the United States in 1880 was $127,825; in 1890, $75,000; in 1898, $131,098. The imports were valued at $12,562 in 1880, at $207,375 in 1890. * Tenth Census, 1880, XV, 833. Mica and mica mining. By C. Hanford Henderson. Pop. Sci. Monthly, 1892, XLI, 652. The mica veins of North Carolina. By W. C. Kerr. Trans. Amer. Inst. Min. Eng., 1879-80, VIII, 457-462. Geology of the mica deposits of the United States. By J. A. Holmes. Eng. and Min. Journal, Feb. 11, 1899, LXVII, 174. J ' /~ v ">. QSw~* 1~/^- 320 NATURAL FERTILIZERS. NATURAL FERTILIZERS.* Mineral Phosphates.! Apatite. The mineral phosphate, apatite, contains theoretically 42.3% phos- phoric acjd, 55.5/ linie, and 3.8% fluorine. Analyses show from 39 to 41.37% phosphoric acid. Found in crystalline and stratified rocks, but more plentifully in the former, especially in metamorphic limestone, in gneiss and schist. Apatite both massive and crystalline ; some crystals very large, 550 Ibs. Canadian deposits} in Quebec and Ontario in metamorphosed Laur- entian rocks, usually associated with limestone. In forms of veins, beds, and irregular pockets from an inch to many feet thick. Methods of mining and preparing. Apatite lands generally of little value for other purposes. Effect of Florida phosphate discoveries on Canadian apatite business. Phosphorite. Phosphorite includes the vitreous, earthy, scaly, and fibrous forms of apatite. It is found in Spain, Germany, and near Bordeaux, France, in veins and pockets. Not found in United States. Rock Phosphates. Rock phosphates have not the structure or composition of a definite mineral. Nodular phosphates. Nodules rolled and irregular in shape, varying in weight from a few grains to several tons. Formed by erosion of marl beds. Artificial concentration at Bel garde. * The American Fertilizer, an illustrated magazine, published at Philadelphia. Mineral phosphates as fertilizers. By H. W. Wiley. Year-book U. S. Dept. Agricul- ture, 1894, pp. 177-192. t Nature and origin of deposits of phosphate of lime. By R. A. F. Penrose, Jr. Bui. 46, U. S. Geol. Survey. Washington, 1888. (This work contains a full bibliog- raphy of the subject up to the date of its publication.) The phosphates of America. By Francis Wyatt. Fifth edition. New York, 1894. Florida, South Carolina, and Canadian phosphates. By C. C. Hoyer Millar. London, 1892. I Apatite deposits, Ottawa county, Quebec. By J. F. Torrance. Geol. Survey of Can- ada, 1884, J. 322 NATURAL FERTILIZERS. Local accumulations or concentrations on land or in stream beds in South Carolina. Worked in South Carolina only since 1868. Dredged from streams or dug from open pits. Burning off 12 to 18% of water. In Florida the phosphates are in Eocene, Miocene, and recent deposits.* As pockets in lime- stone. Prospected by shafts and bore holes. Loose local accumula- tions of nodules and boulders. Disintegrated rock. Deposits often cover several acres ; 5-50' thick. Mined in open cuts. As pebbles in existing streams ; dredged out. Tennessee t phosphates are in Devonian shales. Horizontally bedded rocks, locally rich. Form of the outcrop; tracing the beds. To be worked like coal mines. Fertilizer works are at Boston, New York, Philadel- phia, Baltimore, and Charleston. The phosphates of Arkan- ' : 7 Fig. 137. The phosphate rock production of sas. the United States since 1871. ' Florida land pebble phosphate. By W. B. Phillips. Eng. Min. Journal, Feb. 17, 1900, LXIX, 201-2. By T. C. Meadows and L. Brown. Trans. Amer. Inst. t The phosphates of Tennes Min. Eng., 1894, XXIV, 582-594. The white phosphates of Tennessee. By C. W. Hayes. Trans. Amer. Inst. Min. Eng., 1895, XXV, 19-28. The Tennessee phosphates. By C. W. Hayes. Seventeenth ann. rep. U. S. Geol. Sur- vey, pt. II, 513-550. Washington, 1896. New source of phosphate rock in Tennessee. By J. M. Safford. Amer. Geologist, Oct., 1896, XVIII, 261-264. 324 NATURAL FERTILIZERS. Guano. Guano is bone phosphate of lime, with hydrous phosphates and im- purities. Deposits formed of the excrement of birds. Considerable beds on islands off the coast of Peru.* These deposits are preserved by the arid climate. Irregular in form. Ammonia and phosphorus the fertilizing ingredients. Beds not extensive, and supply limited. Greenland Marls. Greensands, or glauconite marls, are soft sedimentary deposits whose fertilizing ingredients are phosphoric acid, potash, and lime. They occur in regular apparently horizontal beds, in Cretaceous rocks of New Jersey, t Tertiary of North Carolina, Eocene Tertiary of South Carolina, and prob- ably throughout the Cretaceous and Tertiary areas of the South and South- west. Value of marls to agriculture of New Jersey. 1,080,000 tons dug in New Jersey in 1882. Method of using. Value: will not bear much transportation. Treatment of greensands at Belgarde, France, to save phosphatic nodules. Gypsum. (See pp. 286-288.) Gypsum, or " land plaster," occurs in regular stratified beds. It is quarried and crushed before it is put on the market. Extensively quarried in New York, Nova Scotia, Sandusky, Ohio; Michigan, and Kansas. (For lime, see p. 282; for chalk, see p. 284; for niter, see pp. 242-244.) * Note on Clipperton Atoll. By W. J. Wharton. Quarterly Journal Geol. Soc., May 2, 1898, LIV, 228-229. Phosphatic guano islands of the Pacific Ocean. By J. D. Hague. Amer. Journal Sci., 1862, LXXXIV, 224-243. t Origin and classification of the greensands of New Jersey. By W, B. Clark. Journa.1. (Jeol., February-March, 1894, II, 161-177. 326 MONAZITE. MONAZITE.* Monazite is a phosphate of cerium, lanthanum, and didymium, but it contains a small amount of thoria, which makes it valuable for its present Uses. For making the mantels of incandescent gas burners. Occurrence. It occurs as small crystals scattered through certain granites and After the decay of the rocks the monazite is mechanically concen- trated by water. Formerly mined in North Carolina! from small placer deposits. The largest monazite deposits known are in the beach sands of the coast of Brazil near Prado, 285 miles south of the city of Bahia. The sands are derived directly from the Cretaceous sediments that form the shore bluffs, but these sediments are derived from the older crystalline rocks. The first shipments from Brazil sold for $425.00 a ton; in January, 1900, monazite was quoted in New York at $140.00 a ton. * Monazite. By L. M. Dennis. Mineral Industry for 1897, VI, 487-494. Engineering and Mining Journal, Jan. 28, 1898, LXV, 132; April 8, 1899, LXVII, 407. t The monazite districts of North and South Carolina. By C. A. Mezger. Trans. Amer. Inst. Min. Eng., 1895, XXV, 822-826. Monazite. By H. B. C. Nitze. Sixteenth ann. rep. U. S. Geol. Survey, pt. IV, 667-693. Washington, 1895. (Contains bibliography.) Monazite and monazite deposits in North Carolina. By H. B. C. Nitze. Bui. 9, North Carolina Geol. Survey. Winston, 1895. ~ $28 ROAD MATERIALS. ROAD MATERIALS.* Reference is here made only to road-metal or top-dressing for common macadam or telford roads. The essential qualities of good road-metal are : that it pack hard and smooth ; that it resist the wear of traffic and of weather ; that it pro- duce as little dust and mud as possible. Toughness as against hardness and brittleness. Inferior materials, t Materials that fail to meet the above requirements are more or less objectionable. Feldspathic rocks on decay, or when powdered, form kaolin, a very sticky mud when wet and fine dust when dry. Syenite (80% feldspar), granite, gneiss. Clay shale composed of clay ; when crushed makes mud or dust. Limestone too soft, though much used ; easily ground to mud and dust. Clean sandstone has no binding and is too loose. Clean hard pebbles from stream, if alone, do not pack readily. Superior materials. Gravels of hard rock with binding materials. Paducah, Ky., gravels cemented by iron. Sandy shales. Mauch Chunk red shales of Pennsylvania with iron cement. Chert gravel, natural or artificial. Good roads of the chert region of Missouri, Arkansas, and Ten- How the gravels accumulate in streams. Necessity of screening them. Fresh gravel from the zinc regions of Missouri. Influence of the lime in hardening. * Geology of the road-building stones of Massachusetts, with some consideration of simi- lar material from other parts of the United States. By N. S. Shaler. Sixteenth ann. rep. U. S. Geol. Survey, 1894-95, pt. II, 277-341. Washington, 1895. Die Baumaterialien der Steinstrassen. Von E. Dietrich. Berlin, 1885. Bulletins of the Office of Road Inquiry, U. S. Dept. of Agriculture, Washington, D. C. The common roads. By N. S. Shaler. Scribner's Magazine, Oct., 1889, VI, 473-483. Roads and road-making. By F. V. Greene. Harper's Weekly, August 10, 1889. Pavements and roads: their construction and maintenance. By E. G. Love. New York, 1890. Road materials and road-building in New York. By F. J. H. Merrill. Bui. N. Y. State Museum, IV, no. 17. Albany, 1897. t Rocks suitable for road-making. By N. S. Shaler. Stone, 1896, XIII, 571-572. I UN-^-t/Co 330 ROAD MATERIALS. Novaculite and jasper gravels. Breaking up of novaculite by joints. Accumulation in stream channels. The jasper beds of California, Wisconsin, and North Carolina. Hardening road-metal. Influence of iron, illustrated by the canga of Brazil, and the iron- bearing gravels of Paducah, Ky. ; influence of lime. Possibility of improving poor materials with iron. Distribution of materials. Modern gravels in glaciated areas. Modern gravels in stream channels; dredged at Evansville. Sandy shales with other sedimentary rocks. Chert gravels, Lower Carboniferous and Silurian. Novaculite follows structural features. Where iron may be had for hardening. Poor iron ores available. 332 SOILS. SOILS.* Residuary soils. Decay of rocks in place. Varying character and fertility according to the rock matrix. Lake- and sea-bottom soils of recent date. The Tertiary and Pleistocene of the Gulf States. Origin of these sediments. The lake bottoms of Pleistocene times. The San Joaquin and Santa Clara valleys. Adobes from three sources : 1. Rocks decayed in place. 2. Washed down from such decayed beds. 3. Wind-blown.t Talus soils. Talus from cliff and rock slopes. Soil by decay of rock -fragments. Alluvial soils. Silts deposited by water. Origin of the alluvial silts. Fertility of river bottoms due partly to organic matter in the silts. Silting up of deltas. Glacial soils.* Origin of the glacial drift. Variety and mingling of its ingredients. Glacio- a-lluvial soils. Silts draining from glaciers. Loess deposits in water and by wind. Loess as a soil in the Mississippi valley. *The soils of Tennessee. Bui. Agr. Expr. Station of Tenn., Sept. 1897, X, no. 3. Knox- ville, 1897. The soil: its nature, relations, etc. By F. H. King. New York, 1895. The origin and nature of soils. By N. S. Shaler. Twelfth ann. rep. U. S. Geol. Survey, 1890-91, pp. 213-345. Washington, 1892. Rocks and soils : their origin, composition, and characteristics. By H. E. Stockbridge. New York, 1888. Composition, mode of formation, and properties of soils. By E. A. Smith. Geol. Sur. of Alabama for 1881 and 1882. pp. 1-154. Montgomery, 1883. 1 1. C. Russell in Geol. Magazine, 1889, pp. 289, 342. t Soils of Illinois. By Frank Leveritt. Report Illinois Board of World's Fair Com. Springfield, 1895. I Loess of North America. By R. E. Call. Amer. Naturalist, May, 1882, XVI, 369-381, 542-549. (Bibliography of loess.) 334 SOILS. Modification of soils. After formation soils are variously modified by changes of temper- ature, by rain, plants, and animals. Leaching action of acidulated waters ; " buckshot " soil. Wind-blown accumulations : Colma, China, adobe of the deserts. Accumulations of volcanic ashes that decay rapidly: Bolivia; Italy. Swamps, marshes, peat-bogs, prairies.* The work of burrowing animals, gophers, squirrels, ants, and earth- worms, t The waste of soils by washing.} Alkali soils. Origin of the alkali. * Origin of prairies. By Leo Lesquereux. Econ. Geol. of Illinois, I, 178-190. Spring- field, 1882. t The decomposition of rocks in Brazil. By J. C. Branner. Bui. Geol. Soc. of America, 1895-96, VII, 295-303. Vegetable mould and earthworms. By Charles Darwin. New York, 1882. t Washed soils: how to prevent and reclaim them. Farmers' Bui., no. 20, U. S. Dept. of Agriculture. Washington, 1894. The economic aspects of soil erosion. By N. S. Shaler. National Geographic Maga- zine, Oct., 1896, VII, 328-338. g A report on the relations of soil to climate. By E. W. Hilgard. Bui. 3, Weather Bu- reau, U. S. Dept. of Agriculture. Washington, 1892. The alkali soils of the Yellowstone valley. By M. Whitney and T. H. Means. Bui. 14, Div. of Soils, U. S. Dept. of Agriculture. Washington, 1898. 336 WATER.* A country's water supply derived (1) directly from rain; (2) from lakes; (3) from rivers; (4) from springs; (5) from wells, (a) ordinary wells, (6) artesian wells. Effect of andesite and other porous rocks on water supply. Topography determines largely the rainfall of a region; effect of the Sierra Nevada mountains on the rainfall of California and the Great Basin. Effect of the Andes upon the rainfall of the west coast of South Amer- ica. Lakes: size, depth, character, distribution; largely controlled by geologic relations. Rivers: location and character fixed by geologic structure of the region. Effect of rapids and water-falls : sources of water power ; detriment to navigation. Utilization of muddy water after filtering. Effect of alum, acids, alkalies, heat and cold. Springs: location, character, size, determined by geologic relations of the rocks. Springs are of all sizes, from the smallest trickling streams to those of great volume. Mammoth Spring of Arkansas dis- charges 9000 barrels per minute. Underground streams ; traced by the use of fluoresceine. Fi 8- 138,-Seotion to illustrate the geo- . . logic reason for a spring Cities and towns often owe their upon a fault line. locations to springs. All spring waters contain mineral ingredients; often used for med- icinal purposes, t Hard water of limestone regions. Soft water of granite and sandstone regions. Mineral springs as health and pleasure resorts. Spring waters vary from extremely cold to boiling hot. Hot springs. Geysers. * The water supply of England and Wales. By Charles E. De Ranee. London, 1882. Mineral waters of Arkansas. Ann. rep. Geol. Survey of Arkansas for 1891, 1. Little Rock, 1892. Mineral waters of Missouri. Ann. rep. Geol. Survey of Missouri, 1890-92, III. Jefferson City, 1892. Water supplies and inland waters of Massachusetts. Part I, rep. on water supply and sewerage, 1887-90. By the State Board of Health, Boston, 1890. The potable waters of the eastern United States. By W. J. McGee. Fourteenth ann. rep. U. S. Geol. Survey, pt. II, 5-47. Washington, 1894. t Natural mineral waters of the United States. By A. C. Peale. Fourteenth ann. rep. U. S. Geol. Survey, pt. II, 49-88. Washington, '1894. 338 i ^-Silurian. Fig. 139. Geological map of the region about Eureka Springs, Arkansas, showing the emergence of springs at a constant horizon. 340 WATER. Wells: wells, except for large cities, are the chief source of water supply for domestic purposes. Ordinary wells, especially in cities, liable to surface contamination and cannot furnish great volume. Why some wells yield soft water and others near by yield hard water. Why water is not always found at the same level in the glacial drift regions. Hard water Fig. 140. Vertical section in the chalk region of southwest Arkansas, showing why the waters of some of the wells are hard while others are soft. Artesian wells* are wells (usually deep) that flow at the surface. Conditions favorable for artesian wells: a porous stratum, below an impervious stratum, with an exposed edge higher than the mouth of the well ; no sufficient outlet lower than the mouth of the well; sufficient rainfall at the exposed edge of ^^^ = __^ the water-bearing bed ^^z^^- -"> --^ - - / - - to completely saturate Fi &- 141. -Section to illustrate the conditions controlling artesian waters. the whole bed. The water-bearing stratum may be either porous or fissured, less disturbed the strata the better. The The underground water of the Arkansas valley in eastern Colorado. By G. K. Gilbert. Seventeenth ann. rep. U. S. Geol. Survey, pt. II, 557-601. Washington, 1896. Preliminary report on artesian waters of a portion of the Dakotas. By N. H. Darton. Seventeenth ann. rep. U. S. Geol. Survey, pt. II, 603-694. Washington, 1896. Report on water supply. By C. C. Vermeule. Geol. Survey of New Jersey, vol. III. Trenton, 1894. Well-boring and irrigation in east South Dakota. By N. H. Darton. Eighteenth ann. rep. U. S. Geol. Survey, pt. IV, 561-615. Washington, 1897. Artesian wells of Iowa. Bv W. H. Norton. Rep. Iowa Geol. Survey, VI. 115-428. Des Moines. 1897. The requisite and qualifying conditions of artesian wells. By T. C. Chamberlin. Fifth ann. rep. U. S. Geol. Survey, 1883-84, pp. 125-173. Washington, 1885. On the occurrence of artesian and other underground waters in Texas, eastern New Mexico, and Indian Territory, west of the 97th meridian. By R. T. Hill. Senate Ex. document 41. 342 WATER. Uncertainties in boring for artesian water due to the variations in the character of the water-bearing bed, and to possible faults. The general principles are simple, but the problems are often complex. Special cases require special study. Artesian waters seldom obtained from crystalline rocks, but some- times from the joints in them. Artesian water not confined to rocks of any particular age. In Cali- fornia they are more abundant in the later formations. Size and strength of flow depends upon : 1. Distance of discharge from outcrop. 2. Porosity of the water-bearing beds. 3. Character of the confining beds. 4. Character of the country between. 5. Height of the outcrop of the water bed. Artesian water important for : City water supplies. Irrigation. Limits of artesian water for irrigation. Medicinal purposes. Examples of artesian well regions. Impossibility of locating water and minerals by the use of the divin- ing rod.* * The mechanical action of the divining rod. By M. E. Wadsworth. Amer. Geologist, Jan., 1898, XXI, 72. The divining rod. Nature, Oct. 14, 1897, LVI, 568-569. The theory of water-finding by the divining rod. By B. Tompkins. Chippenham, Wilts, 1899. Also Nature, Nov. 2, 1899, LXI, 1-4. The divining rod. By R. W. Raymond. Trans. Amer. Inst. Min. Eng., 1882-83, XI, 411; and Eng. and Min. Jour., Feb. 26, 1898, LXV, 256. 344 REPORTS ON MINING PROPERTIES. REPORTS ON MINING PROPERTIES.* Mining properties are usually bought and sold nowadays upon the reports of competent geologists. Samples cannot be depended upon ; and even when samples are trust- worthy, the value of the property is not always determined by the rich- ness of the ore alone. Reports. Reports should be accompanied by maps, sections, assays, and other information relating to the value of the property, such as roads and transportation, water and water-rights, fuel, timber, labor, etc. Legal status of the property. Sampling. ^ The object of the sampling of ore-bodies is to determine the nature and extent of the ores and the value of the property. Method of pits, shafts, and wells. Wells bored with core drills; with churn drills. Method of cross-cutting. Samples to be collected by one's self. Labelling. Locating by surveys or measurements. Care of the samples collected. Specimens that may mislead. How one may impose upon himself. Assaying. The limits of an assayer's responsibility. In sampling great care must be exercised to guard against mine-salting. By salting } is meant the fraudulent tampering with the materials ex- amined for the purpose of misleading the person making the examination. * The responsibilities of the mining engineer. By J. B. Porter. Journal Fed. Canadian Min. Inst., 1898, II, 300-205. t Testing and sampling placer deposits. By E. B. Kirby. Eng. and Min. Journal, July 29, 1899, LXVIII, 130. Notes on the exploration of mineral properties. By H. S. Munroe. School of Mines Quarterly, Nov., 1897, XIX, 9-14. The sampling and measurement of ore-bodies in mine examinations. By E. B. Kirby. Thirteenth ann. rep. State Mineralogist of California, 679-700. Comstock ore-sampling. By John S. McGillivray. Thirteenth ann. rep. State Miner- alogist of California, 701-705. Sacramento, 1896. Sampling ore-bodies. Eng. and Min. Journal, Dec. 2, 1899, LXVIII, 672. 1 Mining reports and mine salting. By Walter McDermott. Engineering Magazine, May, 1895, IX, 311-318. Trans. Kansas Acad. Sci., 1874 (reprint of 1896), 106-111. Mine salting. By O. M. Dobson. The Cosmopolitan, April, 1898, XXIV, 575-583. How bubbles are inflated and pricked. Eng. and Min. Journal, July 28, 1888; same re- printed Dec. 4, 1897, p. 668. 346 REFERENCES TO MINING LAWS. It is liable to be done : On the ground before samples are taken ; In the specimens after they are collected; In the assays. Danger of trusting the records of a mine's monthly output. REFERENCES TO WORKS ON MINING LAW. The law of mines and mining in the United States. By D. M. Barringer and J. S. Adams. Boston, 1897. A treatise on the American law relating to mines and mineral lands. By Curtis H. Lindley. 2 vols. San Francisco, 1897. Mining law. By E. P. Clark. School of Mines Quarterly, 1884, V, 242-258. Historical sketch of mining law. By R. W. Raymond. Mineral Resources of the U. S., 1883-84, pp. 988-1004. Washington, 1885. The law of the apex. By R. W. Raymond. Trans. Amer. Inst. Min. Eng., 1883-84, XII, 387-444, 677-688. Mining laws. Tenth Census, vol. XIV. Washington, 1885. Dissertation upon American mining law. By A. H. Ricketts. Eleventh ann. rep. of the State Mineralogist [of California], 1891-92, pp. 521-574. Sacramento, 1893. American mining code. By Henry N. Copp. The law of mines in Canada. By W. D. McPherson and J. M. Clark. Toronto, 1898. Minng code of the Mexican Republic, second ed. Mexico, 1893. Ley minera y ley de imposto &. la mineria con sus respectivos reglamentos. Mexico, 1894. flTJU ' /WA - firw UVA, , ; flu C.%, /. lC U ? C . 3 A 2_ H, U CfiyUX) "hjbuU \ 6L+~^ *?W^ ' 3 *7 t . ^w . 5