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By R. F. Mehl, C. S. Barrett, A. G. Guy

INTRODUCTION IN the last few years this laboratory has published a series of papers on the mecha¬nism of age -hardening.14,1,6,11,20 Briefly stated it has been proposed that hardening is caused by lattice strains created by lat¬tice coherency between matrix and precipi¬tate; much experimental evidence has been advanced to support this thesis. The system Cu-Be is an attractive one to study. It is a system that exhibits marked age hardening; it ought to be subject to the type of analysis of structural changes hitherto explored and it is a prominent example of "discontinuous precipitation," which, though studied in other cases, 6,20 remains largely unexplained. This research shows that hardening in the Cu-Be system proceeds essentially as proposed earlier.14 Guinier-Preston zones have been observed to form on the {100) planes of the matrix; no transition lattice was found. Aging and overaging were ob¬served to occur most rapidly in the region of discontinuous precipitation-the grain boundary-apparently accelerated there by strain. The Constitution of the Cu-Be System The Cu-Be constitution diagram is shown in Fig I. The structure of the ? phase was determined by Misch16 as of the caesium-chloride type with a lattice con¬stant of 2.598 Å High temperature X ray photograms of 7.2 pct Be alloy made by Kossolapow and Trapesnikow13 led them to conclude that the structure of the P phase is simply disordered body-centered cubic with [ao] = 2.79 Å at 750°C. Previous Work The initial work on the age-hardening of Cu-Be alloys was that of Masing, Dahl, Holm, and Haase. Their numerous papers were published in book form in 1929, sub¬sequently translated.18 The effects of Be content, solution temperature, aging tem¬perature, and cold work on the hardness developed in these alloys were studied. An initial decrease in the electrical conduc¬tivity was observed when strips of a 2.5 pct Be alloy were aged at temperatures from 200 to 350°C; a wire of the same analysis failed to exhibit this decrease when aged at 350°C. A volume decrease of 0.6 pct oc¬curred during aging at 250°C. Microscopic investigations of quenched and aged alloys disclosed a regularly ori¬ented "striping" (ripples) on the a and on the ß grains. In the case of the ß the cause of the striping was held to be decomposition

Jan 1, 1948

By Russell G. Haworth

Three companies, United States Potash Company, Potash Company of America, and International Minerals and Chemical Corporation, are now operating potash mines and refineries in the Carlsbad, New Mexico, area. The three mines are located approximately twenty miles east of Carlsbad. The deposits have been found ideal for mechanized mining methods. This summary has been compiled from information made available by the three operating companies.

Jan 1, 1949

By D. M. Clippinger, J. J. Eidel, J. E. Frost

At Ithaca Peak, one of three peaks situated on Duval Corporation's Mineral Park property, a 'Single pulse of quartz monzonite magma intruded the isoclinally folded Precambrian Cerbat complex consisting of schist, quartzfeldspar gneiss, and amphibolite. The magma reacted with the Precambrian rocks, yielding a quartz-diorite rim. As the magma crystallized within the rim, it produced, progressing in'ward, annular bodies of quartz monzonite porphyry, quartz porphyry, and a distinctive quartz porphyry containing abundant podiform, tabular, and irregular quartz masses. These quartz masses are spatially associated with discontinuous crenulate and tabular quartz veinlets. Following crystallization, the Ithaca Peak stock and part of the surrounding Cerbat complex were fractured, producing a stockwork of predominantly northwest and northeast-trending fractures. The stockwork was then mineralized during a period of decreasing temperature by: ( 1) quartz-pyritechalcopyrite veinlets without distinct selvages and with distinct alteration envelopes in which orthoclase was altered to quartz and sericite; (2) quartz-pyrite-chalcopyrite veins and veinlets with distinct selvages and without distinct alteration envelopes; and (3) pyrite-chalcopyrite- galena-sphalerite veins. The Ithaca Peak stock was pervasively sericitized or argillized. The Mineral Park property is surrounded by a zone of propylitization Alteration and mineralization are coextensive in space and were, at least in part, coincident in time. The Mineral Park property possibly was elevated and exposed twice prior to its present exposure. The protore has been enriched by a factor of three. The Ithaca Peak supergene ore body is conformable with present topography and lies above the present water table. The shape of the ore body was controlled by erosion and oxidation of the previously enriched mineralization. Hematite, goethite, and jarosite present at the surface indicate a high primary pyrite environment, but it is possible to recognize that a small proportion of veins and veinlets contained greater amounts of chalcocite and chalcopyrite than pyrite. The igneous facies on Ithaca Peak are the products of differentiation within a solidifying rim according to Bowen's Reaction series. The innermost facies contain more quartz and orthoclase than the outer facies. Late magmatic quartz in the case of Ithaca Peak contains small amounts of pyrite and molybdenite. It is suggested that this quartz-sulfide mineralization, may also have been the product of differentiation the product of differentiation, may indicate that the later hydrothermal mineralization may also have been the product of differentiation.

Jan 1, 1968

By AIME AIME

ALL sessions of the Mining Geology Committee at the Annual Meeting this year were held jointly with other groups, a plan that seemed to work out to the satisfaction of every one. Certain of these sessions are reported in this issue by others; the ones held on Wednesday are covered here. Ten papers, as published in the February M&M, were on the program for the Wednesday morning session, held jointly with the Society of Economic Geologists. Mr. Eckel made a brief presentation of his paper, on which there was no discussion, and Mr. Peoples presented that of which he was a joint author. D. M. Fraser then discussed a gravimeter survey for chromite in Cuba, which blocked out some 50,000 tons of ore, and F. G. Wells told of work on chromiferous sands in Oregon.

Jan 1, 1943

By G. M. Ault, G. C. Deutsch

The paper reviews the efforts made to utilize powder metallurgy to solve problems encountered when using alloys at high temperatures. The following subjects are discussed: comparison of wrought and sintered super alloys, sintered aluminum powder, porous materials for transpiration cooling, molybdenum, and cermets. TODAY, powder-metallurgy techniques are be-JL coming increasingly important, producing materials which at the present time cannot be made by any other method. Among these materials are high melting-point metals such as tantalum and tungsten, porous metals for filters and lubricant-containing bearings, electrical contacts and electrodes (i.e., tungsten-copper), cutting tools of the cemented carbides, and magnet alloys. In addition, the powder-metallurgy industry has grown because, through the application of its methods, shaped parts, such as gears, can be produced at tremendous rates with a low scrap loss in comparison with manufacture by casting or forging and machining. In the past few years, by utilizing powder metallurgy, several approaches to the problem of high temperature materials have been investigated. In this paper the authors will review some of the studies on application of materials having properties above 1350°F. Since their experience lies in the aeronautical field, possible uses of powder-metallurgy techniques in the production of aircraft en- gines will be emphasized. A large portion of the work is classified, but such a restriction has not eliminated any field from discussion, although limiting the amount of detail it is possible to present. The development of high temperature alloys from powders and porous metals for cooling will be discussed as well as research done on molybdenum and molybdenum alloys, cermets, and intermetallics. Some studies on the utilization of cermets will be considered along with special problems that have been revealed through these investigations. Special interest in certain factors of sintered aluminum powder (SAP) makes it desirable to discuss this material although its use temperature is below the 1350°F limitation set for this paper. High Temperature Alloys from Powders In general, components made from powders for room-temperature application have been investigated with the primary purpose of taking advantage of the high production rates and economies made possible by powder metallurgy. From the standpoint of properties, the ojective of the powder metallurgist has been to obtain a product comparable to the cast or wrought product that is to be replaced. Comparisons of the properties of alloys made by powder-metallurgy methods with those of similar compositions made by casting and forging are reported in the literature.12 In many cases equivalent

Jan 1, 1955

By Walter E. Hopper

The Caddo oil-field, shown in Fig. 1, is located in Caddo parish, northwestern Louisiana. The known producing territory of oil is covered by townships 19 N, 20 N, 21 N, 22 N, and ranges 15 and 16 W., shown in Fig. 2. The center of the field may be taken as Oil City, 24 miles north of Shreveport, on the Kansas City Southern railway. Shreveport is the second largest city in the State, and is the connecting point of five railroad-lines. Drilling at the present time, however, is going on all over northern Louisiana, especially in Caddo and the neighboring parishes. During the winter of 1908-09 I spent 'four months in the Caddo field, under the direction of the Louisiana Geological Survey and the U. S. Geological Survey. II. History and Development. Natural gas escaping at the surface is found at numerous places in northwestern Louisiana. At Shreveport, the plant of the Shreveport Ice & Refrigerating Co. has been lighted by natural gas for 20 years. The well was drilled for water, but was abandoned on account of the gas. A test well, put down in 1905 near the western limits of Shreveport, was driven to 1,650 ft., and encountered indications of gas and oil at various depths, but did not succeed in finding enough to be profitable. Attention was first attracted to the Caddo field in 1895 by indications in water-wells from 40 to 60 ft. deep, in which the pressure of natural gas was noticeable. This indication of gas in a shallow well led to the drilling of the first well in the Caddo field, the old Savage Brothers & Morricell, or the Caddo Lake Oil and Pipe Line No. 1. The rig for this well was erected in May, 1904, and drilling began in June, 1904. The well was bailed Mar. 23, 1905, with a small amount of oil. It was deepened July, 1905, and converted into a "gasser" Jan. 3, 1906. It was abandoned January, 1907. In consequence of the finding of oil in the Savage well, drilling-operations were pushed with energy; and in April, 1905,

Jan 1, 1912

By AIME AIME

PRACTICALLY all the Section delegates as well as a sprinkling of Institute officers and mere members were on hand for the annual business meeting of the Institute on Monday afternoon of the Annual Meeting. President McAuliffe presided, with C. H. Mathewson as associate chairman. Americo Albala was first called on to discuss the work of the Pan American Institute of Mining Engineering and Geology. C. Will Wright said that the need for such an organization was evident, and a resolution was passed asking the incoming President to appoint a committee to investigate cooperation with that body, of which Mr. Albala is executive secretary.

Jan 1, 1943

By T. A. Rickard

The function of a preposition is to show the relation of one thing to another; it is necessary therefore for the writer to select the preposition that indicates the particular relation, otherwise he will fail to express himself clearly. Is it against common sense' to suggest that a Government is justified, morally as well as constitutionally, in preventing the decay of an industry by insisting upon the amalgamation of the prosperous with the needy? All these seven prepositions are used correctly. With the first dredge introduced in Russia, of Werf Conrad, Haarlem, make, this method of alluvial dining became important. Here the prepositions "with", "in", and "of" are used wrongly. He means: "This method of a1lu;ial mining sprang into importance shortly after the first dredge, made at the Werf Conrad, Haarlem, was introduced into ;Russia." The statement itself ii not true, but for that I am not responsible. Once, while I was serving with him, we were frozen in out of sight of land in the Gulf of Pichili in the North of China. Admiral Fisher wrote thus. He has used nine prepositions in making this brief statement. The sequence of three prepositions "in out of" is particularly awkward.

Jan 1, 1931

By W. M. Albrecht, W. D. Klopp, R. I. Jaffee, B. G. Koehl

Kinetic studies were made of the reactions of tantalum with oxygen, nitrogen, and air at 400o to 1500°C. The tantalum-oxygen reaction is linear from 500° to 1250°C. The tantalum-nitrogen reaction follows a cubic rate law at 400° to 700°C and a parabolic rate law at 800" to 1475°C. The reaction behavior in air is initially parabolic followed by a transition to linear behavior. In the search for high-temperature materials, considerable interest is being shown in the refractory metal, tantalum. It is the third highest melting metal with a melting point of 2996°C. Also, tantalum has excellent ductility, making it one of the most workable refractory metals. In considering high-temperature applications of tantalum, the oxidation kinetics of the metal must be known. Such information also serves as a basis for the development of corrosion resistant tantalum-base alloys. Therefore, this study was made to investigate the reaction of tantalum with air, nitrogen, and oxygen. LITERATURE Several oxides of tantalum have been reported. The pentoxide, Taz05, is the only oxide of tantalum whose identity has been established. A high-temperature modification, aTa2Os, has been reported by several investigators.1-4 A low-temperature phase, ßTa2O5, undergoes an allotropic transformation at 1320o to 1350oC. 5-8 Four other oxides of tantalum have been reported. The oxides TaO2, TaO, and Ta4O have been reported by schonberg.9 A suboxide Ta2O, was observed by Wasilewski 6. However, the presence of oxides lower than Ta2O5 is questioned by Lagergren and Magneli.7 In oxidation studies, vermilyeal0 and Peterson, et al.,12 reported one possible phase intermediate between Ta and Ta2O5. Only Ta2O5 was formed in the tantalum air reaction, as reported by Michae1.l3 Several studies have been made on the kinetics of the tantalum-oxygen reaction. vermilyeal4 investigated the range 50° to 300°C and found that the rate of growth of a thin adherent oxide film could be described by the Cabrera-Mott theory. Gulbransen and Andrew15,18 studied the reaction kinetics of tantalum in oxygen pressure of 1/10 atm at 250° to 450°C. At all temperatures the reaction followed the parabolic rate law for periods up to two hours. The oxidation behavior in the range 500" to 1000°C was found to be linear at oxygen pressures of 0.2 to 600 psi according to Peterson. et al.l1 At very low pressures (1 x 10-3 to 2 X lo-' mm of Hg) Gebhardt and seghezzi17 reported linear oxidation at 800° to 1500°C. The reaction of tantalum with air is similar to the reaction with oxygen. Studies have been made by Waber, et a1.,12 and Michae1.l3 Two nitrides of tantalum, TaN and Ta2N are known. Their structures have been determined by Brauer and Zapp 18,19 The tantalum-nitrogen reaction kinetics have been investigated by Gulbransen and Andrews. 15, 16 The reaction follows the parabolic rate law at 500° to 850°C at a nitrogen pressure of 1/10 ,atm. At the same temperature, the tantalum-nitrogen reaction is much slower than the tantalum-oxygen reaction. EXPERIMENTAL TECHNIQUES Material— The material used in this study was high-purity, electron-beam-melted tantalum obtained from the Temescal Metallurgical Corp. The hardness of the as received ingot was 76 Vhn. The analysis of the material is given in Table I. Methods—Cylindrical specimens of tantalum approximately 0.9 cm in diam and 0.5 cm in length

Jan 1, 1962

Separates of all the Technical Publications published in 1931 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found in the Transactions. Copies of these papers have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Institute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Additional copies are sold at the rate of I cent per page; minimum charge, 25 cents. Metal Mining Tech-nical Publi- Title Author Meeting TRanb. cation Volume No. and Page* 411-A.43 Ventilation at the Portovelo Mines, J. P. Harmon New York. T31, 83 Ecuador (18) Feb., 1931 425-A.44 Use of Models for the Study of Mining P. B. Bucky New York, Problems (28) Feb., 1931 Milling and Concentration 375-B.32 Ball Mill Studies, I (53) A. W. Fahrenwald New York, H. E. Lee Feb.. 1931 401-B.33 Experimental Flotation of Oxidized H. S. Gieser New York. Silver Ores (9) Feb., 1931 410-B.34 Flotation of Minor Gold in Large-scale E. S. Leaver New York, Copper Concentrators (32) J. A. Woolf Feb., 1931 414-B.35 Effect of Particle Size on Flotation A. M. Gaudin New York, (23) J. 0. Groh Feb., 1931 H. B. Henderson 416-B.36 Ball Mill Studies, 11.—Thermal A. W. Fahrenwald New York. Determinations of Ball Mill Effi- G. W. Hammar Feb., 1931 ciency (13) H. E. Lee W. W. Staley Iron and Steel Division 38QC.59 Open-hearth Steel Process as a Prob- E. R. Jette New York, C31, 80, 111 Iem in Chemical Kinetics (34) Feb., 1931 381-C.60 Thermodynamic Study of the Phasial Yap, Chu-Phay New York. Equi1ibriain the System Iron-car- Feb., 1931 bon (26) 382-(3.61 Influence of Dissolved Carbide on the Yap, Chu-Phay New York, Equilibria of the System Iron-car- Feb., 1931 ban (19) 383-C.62 Research on Blast-furnace Slags. R. S. McCaffery New York, Three papers (88) Co-workers Feb., 1931 384-C.63 Statistical Analysis of Blast-furnace K. S. McCaffery New York, C31, 60, 70 Data (13) R. G. Stephenson Feb., 1931

Jan 1, 1931

By Sherwin F. Kelly

THE present lull in engineering activities presents an advantageous moment for inquiring into the position now occupied by geophysics in its various fields of application. The recent over-expansion in all lines of work resulted in an uncritical employment of these methods of exploration which was bound to have its harmful reaction. The pendulum has now swung back, producing a decidedly hypercritical attitude toward the new science that had been recently welcomed so joyfully as the panacea for prospecting troubles. The severe retrenchment in exploration has forced upon us a period of waiting and, it is to be hoped, of profitable contemplation. This can well be employed in trying to pass a reasoned judgment on what position geophysics should occupy in the new geological exploration programs that will inevitably ac- company the looked-for industrial recovery.

Jan 1, 1931

By Messervey, J. P.

NOVA SCOTIA is sharing in the rapid advance of the mining industry that is one of the remark- able features of Canada's recent progress. The production of coal and gypsum has increased rapidly, and there has also been a marked development in the mining of gold, salt, zinc, copper and other minerals. Coal, the basis of the principal mining industry in the Province, was discovered by the early explorers on the shore of Cape Breton Island, and used by the garrison at Halifax as early as 1749. The first government record shows total annual sales amounting to 1668 long tons in the year 1785, while last year production was 6,643,000 long tons. The principal mines are discussed in a separate paper by Alexander L. Hay1.

Jan 1, 1928

By D. V. Carter, D. C. Williams

Four oil discoveries were made in east and east central Texas during 1940, three of which represented new fields. In the Chapel Hill field, Smith County, oil was found where formerly only gas and distillate were produced. The three oil fields discovered are: Hawkins, Wood County; Pittsburg, Camp County; and Tehuacana, Limestone County. Important extensions were made to the following fields: Bazette, Navarro County; Long Lake, Anderson and Leon Counties; Cayuga, Anderson, Freestone and Henderson Counties; Opelika, Henderson County; and Talco, Titus and Franklin Counties. At the close of the year 54 oil and gas fields were producing in the district. There were 13 other fields, 11 oil and 2 gas, which have been abandoned. The East Texas field led the district in the number of completions for the year. During the year about 622 wells (oil and distillate wells included) were completed and 80 wildcats were drilled. Production and Proration During the year 170,424,685 bbl. of oil (distillate production included) were produced in the district—a decrease of 2.6 per cent from the 175,053,729 bbl. (distillate production included) during the preceding year. The district's production for the year 1938 was 182,369,484 bhl. As usual, most of the district's annual production was in the East Texas field, which produced 139,095,694 bbl. (distillate production in- cluded) during 1940, or 81.6 per cent of the total oil produced as compared with 141,333,317 bbl. (80.7 per cent) for 1939. The December estimated daily average production in the district was 424,565 bbl. The district accounted for 34.9 per cent of the state's annual production, compared to 36.7 pcr cent of the state's 1939 production. The decrease in production for 1940 may be attributed to changes made in proration schedules. Any material changes in the district's annual production may be considered for the most part as a reflection of proration-schedule changes affecting the East Texas field, since it is by far the most important field in the area. The entire state was subject to 71 shutdown days for the year; the East Texas field to 131; and the Rodessa field (Cass County, Texas, portion) to 5 days. No important changes were made in field rules and regulations during the year regarding the allocation of oil in individual fields in this district. Discoveries The Hawkins field is in southeastern Wood County in and principally north of the town of Hawkins. Development to date indicates that the field is somewhat of an elongated anticline trending slightly east of north and the proved oil area appears at this time to cover approximately 4000 acres. The oil production has been secured from the Woodbine sand, Upper Cretaceous; a considerable quantity of gas has been encountered in the Sub-Clarksville formation (Eagleford shale) in the higher part of the structure. It appears that a free gas

Jan 1, 1941

By D. C. Williams, D. V. Carter

Four oil discoveries were made in east and east central Texas during 1940, three of which represented new fields. In the Chapel Hill field, Smith County, oil was found where formerly only gas and distillate were produced. The three oil fields discovered are: Hawkins, Wood County; Pittsburg, Camp County; and Tehuacana, Limestone County. Important extensions were made to the following fields: Bazette, Navarro County; Long Lake, Anderson and Leon Counties; Cayuga, Anderson, Freestone and Henderson Counties; Opelika, Henderson County; and Talco, Titus and Franklin Counties. At the close of the year 54 oil and gas fields were producing in the district. There were 13 other fields, 11 oil and 2 gas, which have been abandoned. The East Texas field led the district in the number of completions for the year. During the year about 622 wells (oil and distillate wells included) were completed and 80 wildcats were drilled. Production and Proration During the year 170,424,685 bbl. of oil (distillate production included) were produced in the district—a decrease of 2.6 per cent from the 175,053,729 bbl. (distillate production included) during the preceding year. The district's production for the year 1938 was 182,369,484 bhl. As usual, most of the district's annual production was in the East Texas field, which produced 139,095,694 bbl. (distillate production in- cluded) during 1940, or 81.6 per cent of the total oil produced as compared with 141,333,317 bbl. (80.7 per cent) for 1939. The December estimated daily average production in the district was 424,565 bbl. The district accounted for 34.9 per cent of the state's annual production, compared to 36.7 pcr cent of the state's 1939 production. The decrease in production for 1940 may be attributed to changes made in proration schedules. Any material changes in the district's annual production may be considered for the most part as a reflection of proration-schedule changes affecting the East Texas field, since it is by far the most important field in the area. The entire state was subject to 71 shutdown days for the year; the East Texas field to 131; and the Rodessa field (Cass County, Texas, portion) to 5 days. No important changes were made in field rules and regulations during the year regarding the allocation of oil in individual fields in this district. Discoveries The Hawkins field is in southeastern Wood County in and principally north of the town of Hawkins. Development to date indicates that the field is somewhat of an elongated anticline trending slightly east of north and the proved oil area appears at this time to cover approximately 4000 acres. The oil production has been secured from the Woodbine sand, Upper Cretaceous; a considerable quantity of gas has been encountered in the Sub-Clarksville formation (Eagleford shale) in the higher part of the structure. It appears that a free gas

Jan 1, 1941

By J. H. McCormick

THIS plant, near Marysville, Mont., was planned to treat the ore from the Piegan and Gloster mines, the latter being one of the early and famous producers of the Marysville district. When the mill was closed in 1888, treatment consisted of stamp milling, followed by pans and settlers for pan amalgamation. The extraction was evidently poor; because, a few years later, thousands of tons of tailings were re-treated by the ranchers in the valley below the mill, by the then new cyanide process, and gave a handsome profit. In 1914, the present owners, after laboratory tests and an experimental mill run, decided upon the following treatment: crushing to 40 mesh in cyanide solution, concentration, amalgamation, classification, and cyanidation of sands by leaching, and of slime by agitation and decantation in charges. The ore averaged about $7 per ton, gold and silver, the ratio of weight being 1 oz. gold to 7.56 oz. silver. The ratio of gold and silver in tailings was 1 oz. Au to 36.6 oz. Ag; the quartz vas sharp and, sandy, however finely ground, and rather difficult to slime. The mechanical 'equipment was a No. 5 Symons gyratory crusher; three 10-ft. Lane slow-speed Chilean mills; one Wilfley roughing and one finishing table; one submerged-type Akins classifier; five 26 by 10-ft. fir leaching tanks; one 24 by 7-ft. Dorr thickener; four 14 by 16-ft. Dorr agitators; four 6-compartment double-row zinc-boxes having compartments 18 in. wide, 18 in. deep, and 34 in. long; Johnson zinc lathe; acid and vacuum filter tanks for treating precipitate; roasting furnace; and Case tilting No. 275 crucible furnace for melting precipitate. The mill is driven by electric power supplied by the Montana Power Co. at the following rates, per kw.-hr.: 200 to 300 hp.,.0.68 c.; 300 to 500 lip., 0.61 c.; 500 to 750 hp., 0.55 c.; plus $1 per month per installed motor horsepower.

Jan 8, 1918

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 Alfred H. Bell

Illinois produced 5 per cent more crude oil in 1934 than in 1933, because there was less curtailment, and. the value of the year's production at the wells was 35 per cent more than that of the previous year. The average price of Illinois crude oil in 1934 was $1.13 as compared with $0.87 in 1933, an increase of 30 per cent. The quotas of allowable production for Illinois during 1934, as authorized by Oil Administrator Harold L. Ickes, were as follows: January, February, March, 12,000 bbl. per day; April, May, 12,500; June, July, 12,600; August, 12,500; September, October, November, 12,000; December, 11,700. No other restrictions on production were in effect during the year until Oct. 11, when it was found necessary to prorate the fields to 75 per cent, a curtailment of 25 per cent below the quota fixed by the Federal Administrator. On Dec. 1 the curtailment was reduced to 18 per cent and on Dec. 18, to 15 per cent. Production in Illinois by months during 1934 was as follows: Barrels Barrels January...................... 393,000 July........................ 394,000 February.................... 337,000 August..................... 402,000 March....................... 394,000 September.................. 378,000 April......................... 373,000 October.................... 352,000 May......................... 411,000 November.................. 305,000 June......................... 392,000 December................... 321,000 Total ................... 4,452,000 In spite of higher prices for crude oil, fewer wells were drilled in Illinois in 1934 than in 1933 (Tables 1 and 2). Of the 26 wells drilled, 10 were oil producers, 8 were in proved fields and 2 were in a new pool in Wabash County, l½ miles south of the nearest production, one was a small gas well on the Stubblefield anticline in Bond County, one was an input well for repressuring in the Colmar-Plymouth field, McDonough County, and 14 were dry holes, mostly scattered wildcat tests.

Jan 1, 1935

By T. S. Lundy, J. Askill

J. Askill and T. S. Lundy (Oak Ridge National Laboratory)—Moore has proposed a simple correlation between the activation energy for solute diffusion in fee metals and the atomic volume of the diffusing species using both tracer and chemical-diffusion data. The first point we wish to make is that it is wrong to attempt such correlations without separating the two types of data. Activation energies obtained using tracer techniques cannot, in general, be directly compared with those obtained from chemical-diffusion experiments. A knowledge of the variations of chemical potentials with composition is necessary and chemical-diffusion data must be corrected for such variations, even for dilute alloys, before a comparison is possible. Secondly, for nickel, iron, aluminum, and lead, Moore neglected a number of recently published works, e.g., Al26 and Mn54 in aluminum,46 cr51 in nickel,47 and Fe55 in iron.48 These and others should have been used. If one considers only the tracer diffusion data, there is left no simple correlation of the type proposed by Moore. For example, in the case of solute diffusion in aluminum the only reliable tracer data listed by Moore are for zinc and aluminum. The nickel, cobalt, and iron data of Agarwala49 are representative of near-surface diffusion-not bulk diffusion. In conclusion we suggest that for tracer diffusion data in these fee metals there is no justification for proposing any simple correlation of activation energy with atomic volume using the limited data that are presently available. R. H. Moore (author's reply)—The writer has proposed a simple correlation which is useful in estimating the internal consistency of diffusion data. The accuracy of the correlation is, of course, a function of the number of data available. Lundy and Askill take issue with the writer's decision to include data for the systems: nickel, iron, aluminum, and lead, taking the view that the data are insufficient to establish the correlation. The writer agrees that the data are insufficient and has cau- tioned the reader that the correlation is tentative in these instances. Inclusion of these systems is justified by the interesting trends the correlation reveals. For example, the distinction between interstitial and substitutional diffusion may be clearly established, Figs. 4 and 6, and the behavior of transition elements and nontransition elements is indicated to parallel the behavior illustrated by the silver and copper systems. Lundy and Askill have singled out the aluminum system for special criticism. The writer chose to discuss the data for diffusion of iron, nickel, and cobalt in aluminum in the terms used by the original authors9 and has included the comments of Balluffi.l0 The writer did not intend the reader to conclude that data for these elements should correlate with data for the nontransition elements as Lundy and Askill have evidently assumed. Iron, nickel, and cobalt form intermetallic compounds with aluminum, so the activity coefficients of these elements may be expected to deviate markedly from unity. This may account for the low frequency factors observed by Hirano.9 The nontransition elements, on the other hand, yield relatively simple phase diagrams with no evidence for intermetallic compound formation as in the case of iron, nickel, and cobalt. In dilute solution, Henry's law should be closely obeyed, the activity coefficients should not deviate markedly from unity, and the effect on the activation energy should not be large. The accuracy of the correlation applied to these systems will improve as the data is extended. It does not seem unreasonable to conclude that its extension should be encouraged.

Jan 1, 1965

By V. R. Garfias

Principal events in petroleum operations of Mexico during 1934 have been the completion of three producing wells in the Poza Rica area and the plans for the expansion of operations of the Cia. de Petroleos de Mexico, S.A. (Petromex). Production for 1934 is estimated at close to 38,000,000 bbl., an increase of 4,000,000 bbl. over the previous year; an increase due in large part to the successful development in Poza Rica. The output of the South fields (Golden Lane) and Tehuantepec fields also increased somewhat during the year. Production of natural gasoline increased from 382,000 to 431,000 bbl. in 1934. Crude run in local refineries is estimated at 26,000,000bbl., some4,000,000bbl. more than the previous year. Exclusive of bunker fuel exports totaled 24,000,000 bbl., or 3,000,000 more than in 1933. Domestic consumption increased approximately 500,000,bbl. during the year, reaching a total of close to 13,600,000 bbl., exclusive of ships' bunkers. A total of 148 wells were completed as compared to 91 in 1933 and 40 in 1932. In proven areas, 133 completions resulted in 54 producers and 79 failures. The 15 wildcats drilled during 1934 gave no encouraging results. Seven of these were located in the border zone of northeastern Mexico; three tested possible northeast extensions of the Northern fields; two were drilled for possible extensions of the "Golden Lane" and three were completed in the Isthmus of Tehuantepec. Fields Northern Fields (Heavy Oil District).—There were 34 producing wells and 71 failures completed in the Northern fields, as compared to 20 producers and 20 failures in 1933. Practically all new producers were drilled to the shallower San Felipe formation, while wells drilled to the deeper Tamasopo limestone encountered salt water. Production of the field totaled 11,890,000 bbl., a decrease of 7.5 per cent from the previous year. Acid treatment was attempted during the year in seven wells

Jan 1, 1935

By F. Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimoniallead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1944