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By Mario L. Villa

Argentina's oil production continues in its upward trend. The year 1940 closed with an important increase over 1939; that is, 1,996,371 bbl., or 10.72 per cent. The Government oil fields (Y.P.F.) are responsible for these results, as their total output was 12,474,655 bbl., which compared with the 10,222, 533 bbl. produced in 1939 represent an increase of 2,252,122 bbl., or 22.03 per cent. Fields operated by private companies yielded 8,134,882 bbl., against 8,390,633 bbl. in 1939, a decrease of 255,751 bbl. (3.04 per cent). To the total of 20,609,538 bbl. produced in 1940 in Argentina, the Comodoro Rivadavia field contributed 14,976,222 bbl.; Plaza Huincul, 1,275,814 bbl.; the Province of Salta, 1,845,1977 bbl. and the Province of Mendoza, 2,51I,475 bbl. Table 3 compares the output of companies working in Comodoro Rivadavia. The total increase of 186,819 bbl. (1.26 per cent) registered in the Comodoro Kivadavia area is due only to an intensification of development programs in the known

Jan 1, 1941

By Mario L. Villa

Argentina's oil production continues in its upward trend. The year 1940 closed with an important increase over 1939; that is, 1,996,371 bbl., or 10.72 per cent. The Government oil fields (Y.P.F.) are responsible for these results, as their total output was 12,474,655 bbl., which compared with the 10,222, 533 bbl. produced in 1939 represent an increase of 2,252,122 bbl., or 22.03 per cent. Fields operated by private companies yielded 8,134,882 bbl., against 8,390,633 bbl. in 1939, a decrease of 255,751 bbl. (3.04 per cent). To the total of 20,609,538 bbl. produced in 1940 in Argentina, the Comodoro Rivadavia field contributed 14,976,222 bbl.; Plaza Huincul, 1,275,814 bbl.; the Province of Salta, 1,845,1977 bbl. and the Province of Mendoza, 2,51I,475 bbl. Table 3 compares the output of companies working in Comodoro Rivadavia. The total increase of 186,819 bbl. (1.26 per cent) registered in the Comodoro Kivadavia area is due only to an intensification of development programs in the known

Jan 1, 1941

Accessions AMERICAN ELECTROCHEMICAL SOCIETY, TRANSACTIONS, vol. 33. Bethlehem, Pa. 1918. AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS, BULLETIN, vol. 2. 1918. (Gift of the Association.) AMERICAN YEAR BOOK: 1915. Edit by Francis G. Wickware, New York. 1919. (Gift of D. Appleton & Co.) ANNUAIRE DE LA HOUILLE BLANCHE FRANCAISE. ` By M. Auguste Pawlowski. 2d year. 1918-1919. Paris. (Gift.) BLACK DIAMOND, Vol. 60, Jan.-June, 1918; vol. 61, July-Dec., .1918. (Gift.) Chicago. CANADIAN MINING INSTITUTE, TRANSACTIONS, vol. 21. 1918. Montreal, Quebec. COMPTES-RENDUS DE L'ATHÉNÉE LOUISIANAIS, vol. 4, No. 3. (Gift of Wm. Beer.) EFFICIENCY OF NATURAL GAS AT Low PRESSURES. Abst. of testimony of Samuel S. Wyer before the Corporation Commission of Oklahoma, February 4, 1919. Printed by Empire Gas & Fuel Co., Kansas City, Mo. GEOLOGICAL. INSTITUTION OF THE UNIVERSITY OF UPSALA, BULLETIN. Edit. By Hj. Sjögren. vol. 14, 1917; vol. 15, 1916; vol. 13, pt. 2, 1916. (Gift.) HYDROGENATION OF OILS. Catalyzers and catalysis and the generation of hydrogen and oxygen. By Carleton Ellis. 2d edition. New York. 1919. (Purchase.) INSTITUTE OF METALS, JOURNAL, vol. 26. No. 2. Edited by G. Shaw Scott. London. 1918.

Jan 6, 1919

[Separates of all the Technical Publications published in 1.929 ,are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, maybe found in the TRANSACTIONS.] METAL MINING TECH¬ NICAL PUBLI- TITLE AUTHOR MEETING TRANS. CATION VOLUME No. AND PAGE 182-A-23 The Royal Commission on Mining Henry Louis New York Subsidence Feb., 1929 183-A-24 Cycles in Metal Production D. F. Hewett New York T29t, 65, 93 Feb., 1929 199-A-25 Ventilation ?at the United Verde Oscar A. Glacscr New York T29, 114, 141 Mine Feb., 1929 206-A-26 Air Conditioning in Deep Mines R. W. Waterfill New York T29, 99, 112, Feb., 1929 245-A-27 Bumps in No. 2 Mine, Springhill, Walter Herd New York Nova Scotia (with discussion) Feb., 1929 257-A-28 Misfires: Their Causes, Prevention ? New York and Treatment on Occurrence Feb., 1929 Misfires in Anthracite Coal T. D. Thomas Mines (With Discussion) Misfires in Bituminous Coal W H. Forbes Mines (With Discussion) Misfires in Non-metallic Mining A. W. Worthington (Limestone) (With Discussion)

Jan 1, 1929

By Robert R. Walden, LeMont West

K ENTUCKY'S first acid-grade fluorspar flotation Kmill, shown in Fig. 1, was placed in operation Aug. 1, 1952, by the Pennsylvania Salt Manufacturing Co. at Mexico, Ky. During 1951 a critical shortage of acid-grade fluorspar developed and it became necessary for the company to produce part of its fluorspar requirements. In 1951 the company purchased the Crider and Lennen metallurgical fluorspar mill and an adjacent stockpile of tailing at Mexico, Ky. The tailing, assaying about 26 pct calcium fluoride, originated from log washer and jig mill concentrators in the area. As the mill did not have a fluorspar dryer or convenient rail facilities, the company leased the Burleson concentrator at Marion, Ky., where these facilities were available. At Marion, Ky., on the Illinois Central Railroad, dry acid-grade fluorspar is transported direct to the company's Calvert City, Ky., hydrofluoric acid plant. The Mexico flotation plant was reconditioned and designed to produce acid-grade fluorspar from the jig tailing stockpile. The new plant flowsheet is shown in Fig. 2. The ore feed, old tailing, which contains 10 pct of waste rock and coarse gravel assaying approximately 8 pct CaF,, is bound together by sticky clay

Jan 1, 1955

By R. W. Raymond

Edward Cooper was born in New York City, Oct. 26, 1824. His father, Peter Cooper, to say nothing of manifold reasoils for fame as an inventor and philanthropist, deserves to be remembered as a pioneer in the establishment .of public schools ; and it is not surprising that. he sent his son to one of the democratic institutions in which he was himself so ardently interested. From the public school Edward Cooper went to Columbia College, where he made the acquaintance of Abram S. Hewitt, who was first his tutor, afterwards his traveling companion, brother-in-law, business partner and life-long friend.' For twenty years I was the consulting engineer of the firm of Cooper & Hewitt, and also connected with the work of the Cooper Union, in which they were both deeply interested and faithfully active. On the basis of the intimate knowledge thus gained, I venture an estimate of Edward Cooper's character and career which, if not fully comprehensive, may facilitate a juster estimate than would be reached by the student of those data which the modesty of the man permitted to be placed upon public record.

Jan 1, 1907

By Roger C. Ilsley

The $2.1 billion Milwaukee Water Pollution Abatement Program (MWAP) requires the construction of several miles of underground openings at depths up to 350 feet for the conveyance and storage of sewage and storm water overflows. The system will include approximately 27km (17 miles) of deep tunnels ranging from 3m (10 f t.) to 9m (30 f t.) in diameter, 26 shafts and a pumping station cavern. The facilities will be located primarily in Silurian Age dolomites of the Niagara Group. The rock is characterized as competent with vertical to sub-vertical orthogonal jointing and predominantly thin shale bedding planes. The site investigation was carried out incrementally, commencing on an area wide basis, becoming site specific as facility plans were developed. To achieve cost savings through uniformity and continuity, a computerized data bank was established. Software was developed during the initial stages of the program for the production of borehole logs, structure contour maps, geologic profiles and summaries of data for statistical evaluations. This paper discusses in general terms the collection, compilation and presentation of data necessary for the characterization of the rock mass.

Jan 1, 1984

By C. T. Young, J. L. Lytton

In recent investigations,1,2 the strength and thermal stability of dislocation substructures prepared by 5 to 25 pct room temperature tensile straining and recovery annealing at 120°, 160°, and 200°C have been studied in randomly oriented polycrystalline high purity aluminum. The techniques of transmission electron microscopy revealed that a major source of the strength and stability of dislocation substructures was the formation, during room temperature straining, of well-defined cells bounded by dislocation tangles which rearranged into nearly perfect dislocation networks during recovery, forming the boundaries of subgrains. The strength of such substructures increases with decreasing cell or subgrain size,2"6 and the formation of fine subgrain structures can provide thermally metastable strength at low temperatures and can favorably alter the course of primary creep at elevated temperatures.7'8 For maximum benefit, however, sub-grain growth should be reduced or eliminated. It was, therefore, decided to investigate the use of heterogeneous precipitation on dislocation networks as a means of imparting increased strength and thermal stability to subgrain structures through effective pinning. C.T. YOUNG, STUDENT MEMBER AIME, and J. L. LYTTON, Member

Jan 1, 1970

By Persifor Frazer

CONTENTS. PAGE 1. Committee House of Commons Report (1843).......521 2. Clark (1880).............521 3. Schröder and Schertel (1884).... . 521 4. Committee House of Lords Report (1887).......523 5. Vita (1890).............524 6. Irvine (1890-1)............524 i. Cramer (1891)............525 8. Bailey. Cohen. Tatham and Hartog (1891))......525 9. Morrison (1891)............525 10. Brunner (1891)............525 11. Bell (1892).............585 12. Oades (1892).............526 12a. Purcell (1892)............526 13. Sennett (1892)............526 14. Bulier (1892).............526 1.7. Wiesner (1892))...........526 16. Thomson (1892)............530 17. Fletcher (1892)............530 18. Committee Engineers' Club Report (1892).......530 19. Cohen and Hefford (1892)..........531 20. Discussion Soc. Chem. Ind. (1893). ..532 21. Reuss (1893).............532 22. Thomson (1894—5) ...........535 23. Clowes and Feilmann (1895). ...536 24. Callan (1895)...........536 2.5. Wright (1895)............536 25A. Mabery (1895)............536 26. Re- (1896). ..........536 27. Herman (1896)............ 537 28. Cohen and Russell (1896).......... 537 29. Dennstedt and A hrens (1896). ..537 30. Cohen (1897). ...........537 31. Drehschmidt (1897)........... 538 32. Pfeiffer (1898). .........538 33. Fritzche (1898)............ 540 34. Ost and Wehmer (1899)........... 540 35. Donkin (1899). .........541 36. Beilby (1899)............. 643 37. Berthelot (1900)............ 544

Jan 1, 1908

By Gerald J. Anderson

The Marquette District of Central Northern Michigan is the oldest of the Lake Superior iron districts with a mining history dating from 1852 up to the present. The total production of all types of ore through 1965 was 338,120, 146 long tons. Emphasis up to the 1950's was on mining the direct shipping ores; however, demands for higher-grade and better-structured ores in the last decade has resulted in a complete shift in emphasis to beneficiating the lowgrade Negaunee Iron-formation to produce high-grade iron ore pellets. The Precambrian sediments of the Marquette Range have been correlated with the Animikie Series of the Thunder Bay District, Ontario, and are contained in a westward plunging synclinorium that is approximately 3 3 miles in length and 3 to 6 miles in width. -The rock unit of major economic importance is the Negaunee Iron-formation that reaches a thickness of 2500 feet near the City of Negaunee. The primary iron content of the Negaunee Iron-formation averages 26 per cent, whereas the altered iron-formation approximates 31 per cent. The Negaunee Iron-formation has been divided into three principal types: diagenetic, oxidized, and metamorphic. The ores produced to date fall into four categories: high-grade soft ores, high-grade hard ores, siliceous ores, and concentrates and agglomerates (pellets). The soft ores generally are found in synclines and in fault-trough structures, bounded by mafic dikes along at least one side, and are mainly found in the basal portion of the Negaunee. In contrast, the hard ores occur in the uppermost portion of the Negaunee and are controlled by structural features such as folds, faults, and dikes. Iron-formation that has undergone diagenetic and metamorphic alteration makes up the main beneficiating ore types. Studies on the Negaunee Iron-formation have played an important role in the formulation of many of the theories on the origin of the Precambrian iron-formations.

Jan 1, 1968

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

By Persifor Frazer

INTRODUCTION For various reasons I have not specified the locality where the research indicated in the following pages was undertaken. It will suffice to say that it was on the grounds of a villa once remote from, but now completely surrounded by, its neighboring city, and in close proximity to an industrial establishment of great extent and importance manufacturing many kinds of steel articles and employing upwards of thirty chimney-stacks for power and process work. The problem was to discover the cause or causes of the mortality to trees and plants on the place, and to trace these causes to their origin. Before undertaking this experimental work, the bibliography accompanying this paper was compiled and studied. It appears from an examination of the careful scientific work performed by the ablest French, German, and English chemists during the last 25 years that they are unanimous in assigning the principal-in fact, the overwhelmingly predominant-cause of the destruction of vegetation to sulphur oxides, resulting either from direct- oxidation of sulphur in oil of vitriol works, etc., or from the oxidation of the sulphur from the minerals associated with commercial coal. Schröder and Schertel showed in 1884 that the sulphates deposited upon the leaves are not injurious to the plants; and Freytag proved that free sulphuric acid could not be found

May 1, 1907

By R. E. Radabaugh, J. M. Brown, J. S. Merchant

The Gilman district is on the northeast flank of the Sawatch Range in central Colorado. It has yielded a total of 10,000,000 tons of ore having a value of over $250,000,000. Paleozoic sediments intruded by a Tertiary quartz latite sill and unconformably overlying Precambrian intrusives and metasediments comprise the country rock of the area. The sediments strike northwesterly and dip 8° to 12° northeasterly. Structures in the Precambrian are related to the Homestake shear zone of the Colorado mineral belt. Only minor folding and faulting occur in the sediments. The principal ore bodies are massive sulfide replacement deposits in carbonate rocks. They consist of long, pipe-like mantos in the completely dolomitized Mississippian Leadville Limestone and funnel-shaped chimneys of copper- silver ore cutting across the Mississippian and Devonian strata. Mineralization is continuous from the chimneys into the mantos. The principal ore bodies are roughly in the shape of a four-tined fork which points up dip. Smaller manto deposits occur in the Cambrian Sawatch Quartzite, and fissure veins are present in the Precambrian rocks. The principal minerals in the mantos are marmatite and galena in a gangue of pyrite and manganosiderite. The chimneys consist of a central core of pyrite with erratically distributed chalcopyrite, tetrahedrite, freibergite, and occasional galena with a shell of zinc ore on the outer margin. Both the chimneys and the mantos are surrounded by imperfect shells of manganosiderite and sanded dolomite. The mineralization is of Laramide age. Hydrothermal alteration affects all rock units to varying degrees. Clay mineral alteration halos occur around the ore bodies. Hydrothermal solutions have developed sanded rock, rubble filled channels, and banded zebra textures, principally in the Leadville Limestone. Structural control of the ore bodies is not well defined. Both the location of the district and the chimneys are probably related to basement structures. The mantos are largely controlled by stratigraphic factors and a pre-Pennsylvanian karst topography in the Leadville Limestone, which were modified by hydrothermal activity, and by weak zones of northeasterly trending faults.

Jan 1, 1968

By Howard Martens, Pol Duwez

XPERIMENTS were performed on a Cr-Fc alloy Econtaining 44.7 pet Cr in order to determine the heat evolved during the transformation of the a solid solution into the s phase, and the change in volume accompanying the transformation. Since previous measurements on the rate of formation of a from s indicated that the reaction was quite fast as soon as the equilibrium temperature of 820°C was exceeded by some 50°, standard thermal analysis experiments were performed on heating specimens of s at the rate of approximately 40°C per sec. A definite thermal arrest was observed at 870"C, Fig. 1. This result indicates that the reverse seaction of into a is exothermic. From the heating curve of Fig. 1, taking 15°C per sec as the heating rate in the neighborhood of the transformation, 2.4 sec as the time for transformation, and assuming that the specific heat of the alloy at 850°C is an average between iron and chromium, namely 9.5 cal per mol per "C, the latent heat of transformation is approximately 342 cal per mol. The order of magnitude of this latent heat was also obtained by comparing the heating curve of Fig. 1 with a similar curve obtained with pure iron under identical experimental conditions. It was found that the length of the thermal arrest for s was about 1.8 times as long as that for iron. Since the latent heat of the a to 7 iron transformation is 203 cal per mol1, 2 the latent heat of it to a would be 365 cal per mol, which is in relatively good agreement with the value determined from the heating curve. For the determination of volume change, thermal expansion curves were recorded using a specimen containing 44.7 pet Cr and completely transformed to cr by previous treatment. The curves were recorded at a rate of heating of about 4°C per min and at approximately 840°C a sharr, increase in length of about 0.08 pet took place. Fig. 2. It is therefore established that the specific volume of a near the transformation temperature is about 0.24 pet smaller than that of a, and consequently, when the s phase forms in an a matrix, it would tend to shrink away from the matrix. Since the s phase is known to be extremely brittle, these results offer an explanation for the microscopic cracks often observed in the a phase under the microscope. The results of this study are in qualitative agreement with previously published data on stainless steel 19-9DLa and on a Cr-Fe alloy containing 45 pet Cr.' The increase in density due to the transformation from n to s given in ref. 4 is 0.90 pet. These measurements, however, were made at room temperature. whereas the presently reported 0.24 pet is the change at the temperature at which the transformation takes place during heating. In the graph of Fig. 2, the percentage change in length that would be observed at room temperature is given by the length X, which is about 0.27 pet. This would correspond to 0.81 pet in volume change. Acknowledgment This work was done at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. DA-04-495-ORD-18 with the Army Ordnance Corps, Washington, D. C. The authors wish to thank this agency for permission to publish the results of this investigation. References I H. Klinkhardt: Measurements of True Specific Heats at High Temperatures. Annalen der Physik (1927) 84, pp. 167-200. - H. Esser and W. Runghardt: Influence of the Method, of Dctcrmination on the Measured Heat Content of Iron. Archtvo ffur Dct Eisenhiittenwesen 11934) 8, pp. 37-38. J. J. Gilman, P. K. Koh, and 0. Zmeskal. Delta Ferrite Formation and its influence on the Formation of Sigma in a Wrought Heat Resisting Steel. Trans. ASM 1 1949) 11, pp. 1371-1388. 1 J. M. Thomas: Discussion of ref. 3. Trans. ASM (1949) 41, pp. 3 390-1392.

Jan 1, 1957

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page 1 Wilkes-Barre, Pa May, ?71 1 3 2 Bethlehem, Pa August, ?71 1 10 3 Troy, N Y November, ?71 1 13 4 Philadelphia, Pa February, ?72 1 17 5 New York, N Y May, ?72 1 20 6 Pittsburg, Pa October, ?72 1 25 7 Boston, Mass February, ?73 1 28 8 Philadelphia, Pa May, ?73 2 3 9 Easton, Pa October, ?73 2 7 10 New York, N Y February, ?74 211 11 St Louis, Mo May, ?74 3 3 12 Hazleton, Pa October, ?74 3 8 13 New Haven, Conn February, ?75 3 15 14 Dover, N J May, ?75 4 3 15 Cleveland, 0 October, ?75 4 9 16 Washington, D C February, ?76 4 18 17 Philadelphia, Pat June, ?76, 5 3 18 Philadelphia, Pa October, ?76 5 9 19 New York, N Y February, ?77 5 27 20 Wilkes-Barre, Pa May, ?77 6 3 21 Amenia, N Y October, ?77 6 10 22 Philadelphia, Pa. May, ?78 6 18 23 Chattanooga, Tenn May ?78 7 3 24 Lake George, N.Y. Oct. ?78 7 25 Baltimore, Md. Feb. ?79 7 26 Pittsburgh Pa, May ?79 8 27 Montreal, Canada Sept, ?79 8 28 New York, N.Y. Feb, ?80 9 29 Lake Superior, Mich Aug, ?80 9 30 Philadelphia, Pa. Feb, 81 9 31 Staunton, Va May, 81 10 32 Harrisburg, Pa Feb, 81 10

Jan 1, 1952

(Under this heading will be published notes sent to the Secretary of, the Institute by members or other persons introduced by members.) Development and production. Member open for engagement. Past year in war mineral field work, operation and production. Ten years' thorough experience in both subordinate and executive positions, gold, silver and copper in the United States, Mexico, and South America. Age 37, married. Minimum salary $3600. Interview. South or East. A-577. Engineer and executive. Captain U. S. Army, age 36, expects discharge before July 1. Seven years' mining and metallurgical experience. Six years with large technical college as assistant professor of mining and directing extensive experimental work. Desires position as executive or research engineer with reliable company or as professor of mining with first-class college. A-909. Mining engineer. Twenty-five years' experience including mine and works operation, construction, plant installation, and mine examination. Speaks Spanish. A-1173. Metallurgical engineer. Twelve years' laboratory and operating experience, covering copper blast furnace, roasting, reverberatory smelting and latest Cottrell treater practice on copper dust and zinc dust. Technical graduate. 36 years of age, married. Highest recommendations. Open for immediate engagement. A-2354. Mining engineer. Junior Associate. At liberty about July 1. Captain Heavy Artillery. Single, age 24. Go anywhere. Best refer-ences. A-2843. Engineer. Age 26, single, graduate Missouri School of Mines, B. S. in Mis. Met. E. Desires position with oil or metal company in any capacity. Location immaterial. At present engaged, desires change. A-2844.

Jan 7, 1919

By D. R. Cook, W. M. Shepard, H. T. Morris

The East Tintic district in central Utah has produced ores of gold, silver, copper, lead, and zinc valued at more than $120,000,000. All of this ore has been produced from blind ore bodies in Paleozoic sedimentary rocks that are concealed beneath hydrothermally altered volcanic rocks and cut by intrusive bodies of Eocene age. The Paleozoic rocks, which range in age from Early Cambrian to Mississippian form the core and limbs of a large, northtrending asymmetric anticline that is cut by low-angle thrust faults, high-angle transcurrent faults, mineralized fissures and faults, and normal faults that are both older and younger than the mineralized fissures. The ore bodies generally may be grouped into two classes: ( 1) massive replacement bodies that are rich in silver, lead, zinc and manganese and (2) fissure veins that are valuable primarily for their content of gold, copper, and silver. The replacement ore bodies are localized chiefly in the Middle Limestone Member of the Ophir Formation of Middle Cambrian age where it has been thrust-faulted against older or younger rocks and cut by northeast-trending mineralized fissure zones. The fissure veins primarily are productive only in the Lower Cambrian Tintic Quartzite. Extensive lowgrade deposits of lead-zinc-silver ore recently have been discovered in Devonian carbonate rocks in the Lower plate of the East Tintic thrust fault but as yet are unevaluated. The principal guides to ore include: ( 1) intersections of northeast-trending fissures and crossbreaking faults that brecciate the carbonate rocks; (2) zones of late-stage pyritic, calcitic, and sericitic alteration in the lavas; ( 3) primary geochemical anomalies in the altered rocks; and ( 4) mineral zoning patterns of the known ore bodies. The present development of the Burgin mine would seem to assure the continued productivity of the district for at least a decade.

Jan 1, 1968

By E. N. Harshman

Uranium mining and milling are rather new industries in Wyoming and South Dakota, but, in the past 15 years, ore valued at more than $400,000,000 has been mined and milled in the region. The major uranium deposits are in structural and/ or erosional basins or on the flanks of uplifts. The principal host rocks are medium- to coarse-grained sandstones that were deposited in continental or brackish-water environments and were derived in large part from the granitic cores of the uplifts and the sedimentary rocks that flank the cores. The ages of the host rocks range from Cretaceous to Miocene, but more than 95 per cent of the known reserves in the region are in rocks of early Eocene age. The bulk of the ore in the region is unoxidized and lies below the water table; some oxidized ore has been mined in the Powder River Basin and Black Hills districts. The unoxidized ore comprises pyrite, uraninite and/ or coffinite, marcasite, hematite, jordisite(?), and selenium. Minerals in the oxidized ore include hydrous uranium carbonates, phosphates, and sulfates and hydrous uranium and/ or vanadium silicates. The deposits are in the form of ore rolls that contain from a few hundred to a few hundred thousand tons of ore, ranging in grade from 0.1 per cent to 1.0 per cent U3O8. The rolls are at the margins of large tabular bodies of sandstone that has been altered by the orebearing solutions. The deposits are believed to have resulted from the interaction of an alkaline; oxidizing, ore-bearing ground water and a reducing environment. Exploration guides include the spatial relations of ore to altered sandstone, favorable lithology in the host rock, the content of certain elements and/ or compounds in ground water, and the relation of deposits to major paleodrainages.

Jan 1, 1968

By Leon Orlowski

THE oil-bearing districts of Poland are found on the slopes of the Carpathian Mountains. The oil belt extends from Gorlice southeast to Stanislawow. It is approximately 250 miles long and 30 miles wide, and comprises four geological districts: the western, or Gorlice district; next, to the east, the Krosno district; the Boryslaw district; and, in the extreme southeast, the Stanislawow district. The amount of petroleum produced in Poland from the beginning of the oil industry scarcely totals 26,000,000 metric tons, or 15 per cent. of the estimated supply. Of this amount, 18,000,000 tons have been taken from the fields of Boryslaw within 25 years; and only about 8,000,000 tons from all other fields within a period twice as long, although some of these other fields represent just as good possibilities as did Boryslaw at the beginning of its development. The Polish oil industry was severely stricken by the war. The retreating Russian armies, in 1915, destroyed a large number, of the existing oil wells, nor was the post-war period favorable for the development of this industry;; the money and credit stringency interfered with the expansion of drilling. But since 1921 there has. been a slow steady increase in production and there is now every reason to believe that conditions in the industry will improve. In fact, an increase in new drillings has been reported for the current year. The production of crude oil in Poland, in 1913, amounted to 1,113,668 metric tons. In 1914, the production declined- to 655,600 metric tons. In 1921, the production was 705,596 tons; in 1922, 712,428 tons, and in 1923, 737,182 tons; or more than 5,000,000 bbl. But the fields have a much greater potential output, which could be realized were the capital available for prospecting and new drilling. The principal producing, and at present most exploited, fields are around Boryslaw and Schodnica. These fields were developed rapidly for in the first year of their modern exploitation the wells were gushers of moderate depth. However, as a result of heavy drilling, the shallow folds have been exhausted and oil can be reached now only by deep drilling. Wells of almost 5600 ft. have been drilled in Boryslaw. Because of these drilling conditions, a large number of engineers and workmen specially skilled in deep drilling are to be found in this field.

Jan 3, 1925

By Dr. O’Neil Thomas J., Donald W. Gentry

"If you can hold a board of cross directors In happiness against their gauzy schemes; If you can dodge the wrath of the electors Till dividends will flow as in their dreams; If you can make a mine pay from the grass roots No matter what the time or place or year; Then on my soul until the final blast shoots We'll add the title "MINING" when we call you "ENGINEER. " -From Wayne Darlington, "The Mining Engineer, " The Engineering and Mining Journal, Vol. 98, Sept. 26, 1914, p. 587. REASONS FOR THIS CHAPTER Up to this point in the book the material presented has addressed the fundamental parameters associated with the evaluation of mining ventures and other investment alternatives. The procedures and techniques illustrated represent the basic approach to project evaluation, particularly when considering the normal engineering economic analysis of investment proposals. The evaluation procedure is complicated, however, when dealing specifically with mining-related investment proposals. These complicating factors are invariably directly related to the many special characteristics of the mining industry. Many of these special features such as tax policies, revenue and cost estimation, and ore reserves have been addressed in previous chapters. In addition to the many special features of mining which directly impact, in a quantitative manner, the various line items in the pro forma income statements of a cash flow analysis, other features of mining affect evaluation procedures in a more general manner. The main purpose of this chapter, then, is to provide an exposition of some of these more qualitative factors. We hope this will enable the reader to recognize these factors in mine evaluation practice and to make suitable adjustments in his or her analysis.

Jan 1, 1984