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By James H. Courtright, Kenyon Richard

L. H. Hart (Chief Geologist, American Smelting & Refining Co.)— Because of a widely recognized association between breccia pipes of one form or another and many important copper deposits, conditions under which breccia pipes develop have been of great scientific interest for many years. Since these phenomena first attracted attention, many theories have been advanced to explain their origin. This is not unexpected, since it is likely that they have been formed by and under a wide range of conditions. Moreover, the entire subject is confused by the fact that the term brec-cia pipe is applied to a wide variety of occurrences. To discuss any part of the subject intelligently, therefore, it is necessary to start with definitions of the terms used. In their discussion of the Toquepala deposit, Richard and Courtright have carefully defined the terms they have used in their presentation of a very logical geological history of Toquepala breccias. This is a real contribution, as there is no reference in the literature known to the writer where the history of a series of breccia pipe epochs, confined essentially within one channelway, may be read with the degree of certainty that appears to be possible at Toquepala. Although the following comments are intended primarily to emphasize points brought out in the article by Richard and Courtright, certan subsequent detailed mapping by Hollister and Houston7 within the main central mineralized area of the Toquepala deposits not only supports most of Richard's and Courtright's con- clusions but also contributes additional facts that strengthen and broaden the whole concept of the origin of the Toquepala breccia pipes. In detailed mapping by Hollister and Houston,' the most significant feature disclosed is a well developed system of concentric fracturing in rocks peripheral to the main breccia pipe throughout an arc of 300°, interrupted only by the late dacite agglomerate in the north quadrant. Although Richard and Courtright noted that such fractures were developed in the southern and southeastern areas, continuity in the east and west quadrants is established by consistent orientation of the stronger set of fractures and joints. The existence of these structural weakness trends is emphasized by the emplacement of dike-like phenomena in and along members of this fracture system. Richard and Courtright described one of these dikes in the southeast quadrant. They referred to it as a ring-dike, composed of dacite porphyry. This suggests an apparent structural control of at least a part of the dacite porphyry intrusion by features related to the Toquepala breccia pipe center. This raises a perplexing question, since the dacite porphyry intrusion had been presumed to antedate breccia pipe activity. However, if this ring-dike is related to the breccia pipe center, it may indicate that some part of the dacite porphyry intrusion advanced in a manner resulting in an intensely localized stress center, which produced the concentrically arranged fracture system. The ring-dike would then appear to be evidence strongly sug-

Jan 1, 1959

By AIME AIME

EVERETTE LEE DEGOLYER, past President of the Institute and Anthony F. Lucas Medalist, was presented with the John Fritz Medal at a dinner at the Wal-dorf-Astoria Hotel in New York, Jan. 14. Dr. DeGolyer is the third representative of the Institute in recent years to receive the John Fritz Medal which is awarded jointly by the four Founder Engineering Societies through a board composed of sixteen past presidents. In 1938 Paul D. Merica was given the award "for important contributions to the development of alloys for industrial uses" and in 1933 the distinction was given to D. C. Jackling "for notable industrial achievement in initiating mass production of copper from low-grade ores through application of engineering principles."

Jan 1, 1942

By AIME AIME

THE MILLING PROGRAM on Monday required a morning and afternoon session with a special luncheon of the Milling Committee in the Engineers Club at noon. Grinding and flotation were the main subjects of the papers which drew an attendance of fifty or more at each session. Under the direction of Chairman Arthur F. Taggart in the forenoon, all papers on flotation and general milling were considered, leaving the, after- noon free for crushing and grinding, with Dr. Galen H. Clevenger in the chair. The high spot was the first public presentation of the idea of size reduction of minerals by explosive shattering.

Jan 1, 1932

By AIME AIME

WHETHER by the Mohawk Trail, Sound steamer, air plane, railroad or any other route or mode of locomotion, all roads will lead to Boston the week of National Metal Congress, Sept. 21-25. The Institute of Metals and Iron and Steel divisions of the Institute are then to meet jointly at the Hotel Statler, and the American Society for Steel Treating, the American Welding Society, the Society of Automotive Engineers and the Iron and Steel Division of the American Society of Mechanical Engineers present carefully planned programs at their respective sessions. The National Metal Exposition will be held on Commonwealth Pier.

Jan 1, 1931

Jan 1, 1885

By B. L. Landrum, P. B. Crawford

Theoretical and potentiometric model studies have been made of the effect of non-uniform lateral permeabilities on pattern sweep efficiency and production capacity in waterflood and gas-cycling programs. It is shown that a diflerence in directional permeability by a factor of three may result in a sweep efficiency of only 43 per cent for a five-spot pattern or a sweep of either 79 or 38 per cent for a direct line-drive square pattern, depending on the direction of the line-drive flood. Changes in the pattern conductivity varied from about 0.8 to 1.34 over this same permeability variation, depending on the pattern used. It is suggested that measurements be made to determine the possible magnitude and extent of the directional permeability phenomenon early in the field developinent and certainly prior to the initiation of any fluid-injection progmm. INTRODUCTION Irregularities in reservoir sand properties long have been a major difficulty to anyone attempting to explicitly describe the field characteristics of oil production. In particular, it is well known that vertical and lateral permeabilities often differ appreciably; however, the existence of large regions with lateral permeabflity variation is not widely recognized. A number of years ago, extensive studies were conducted by the Secondary Recovery Research Labcratory of the Pennsylvania Grade Crude Oil Association, primarily on the Bradford field. Johnson and Hughes' reported a permeability trend in the northeast-southwest direction. They indicated that flow in the preferred direction may be 25 to 30 per cent greater in that direction than in the northwest-southeast direction. They also reported that similar effects may be found in other nearby fields. The origin of the permeability variation has been discussed by Griffith Hutchinson' described the results of labora- tory tests on limestone cores, pointing out that per-ferential directional permeabilities were significant in one-half of 10 formations studied and that the average permeability ratio was 16:1. Barfield, Jordan and Moore analyzed the fluid-injection displacement performance in the Spraberry and reported that the effective ratio of permeability parallel to the major axis to the permeability perpendicular to this axis was 144:l and that it inclined along an angle of about 30". To prevent the reduction of sweep efficiency which would normally result from flooding or cycling in such reservoirs, well spacing could be varied from the customary square to a diamond-shaped pattern. Johnson and Hughes' presented a method for determining the desired shape. Another method will be discussed in detail in the next section. It is the purpose of this paper to investigate quantitatively the effect of directional permeability upon the sweep efficiency and production capacity of the five-spot and line-drive well patterns. Information currently in the literature will be applied to this particular problem and augmented by a potentiometric model study. It is stressed that the effects herein discussed may or may not be of great importance because field data on this phenomenon are far too scant to form such an opinion. It is suggested that, if conditions similar to those found by Johnson and Hughes frequently exist (as may well be the case), more consideration cdrtainly should be given to this problem.

By Paul M. Tyler

NOW that the dust of World War II has settled and we and our allies are faced with extravagant losses of men, money, and materials, virtually the only hope that the United States and Britain have in the way of reparations lies in the capture of industrial, technical, and scientific secrets. Even during the war American and British scientists and technicians gained access to German factories, questioned German personnel, studied German documents, and endeavored generally to keep pace with new discoveries in science, industrial technology, and process development. Under various agencies this work continued for two years after the war. Altogether at least 600 American scientists and industrialists have gone to Germany and brought back reports and several times as many British, Canadian, and. Australian investigators have been similarly engaged under co-operative arrangements designed to assure the maximum of coverage with a minimum duplication of effort. As a result of these investigations and document studies, about 500 or 600 reports have been prepared on metallurgical and allied subjects. Those by American authors or joint teams have been listed in the annotated Bibliography of Scientific and Industrial Reports, issued by the Office of Technical Services in the U. S. Department of Commerce. Many of the British reports are also available in this country through the same office or through a British representative in New York. Since it was my duty to read most of these reports for

Jan 1, 1948

By J. E. Tobey

THERE are a lot of good things about this great industry of ours. Let us stop commiserating and consider some of the things that are right in this business. Coal is number one in the basic material industries. Our civilization owes more to it than to any other basic commodity. We are literally immersed in the benefactions of coal. In cur man-made world it is indispensable and we are constantly surrounded by objects, materials, and services which owe their existence to coal. Practically all the important materials, such as iron, steel, brick, cement, lime, rubber, glass, cotton, and wood have felt its magic touch.

Jan 1, 1939

By Richard G. Warren, Michael M. Minor, Gayle J. Thomas

INTRODUCTION Los Alamos Scientific Laboratory (LASL) initiated its effort in the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR), a part of the Department of Energy (DOE) National Uranium Resource Evaluation (NURE) program, in late 1975. Since that time, LASL has completed sampling of the Rocky Mountain states of New Mexico, Colorado, Wyoming, and Montana at a density of about one water or waterborne sediment sample per 10 km2 and has sampled about 85% of Alaska at a density of at least one per 25 km2. Analytical results for these samples are reported by National Topographic Map Series (NTMS) quadrangle. All collection and analytical procedures have been standardized from the outset (Sharp, 1977; Sharp and Aamodt, 1978). Until early 1979, only uranium results were reported for these samples; thereafter, results include analyses for at least 42 additional elements in the sediment samples. Each LASL HSSR report also includes a discussion of the relationship of these analytical data to known or possible uranium resources; more recently, these data have been re- examined for their relationship to resources for other metals (Beyth et al., 1980; 1980a). Analytical results for LASL HSSR sediment samples are both comprehensive, including 43 elements, and precise, allowing close inter-comparison of data between quadrangles. A recent HSSR study shows that elemental concentrations in sediment samples from the Dixon Entrance quadrangle in Alaska are insensitive to the choice of sieve size fraction and do not vary significantly between stream locations a few meters apart, except for extremely high elemental concentrations (Warren, et al., 1980). Elements that are particularly reproducible include thorium, hafnium, and the .ram earth elements. Fortunately, sensitivities for these elements, which are often associated with uranium, are excellent by the nondestructive analytical technique of neutron activation analysis that LASL employs. Wet chemical techniques may not always give reliable results for these elements in sediment samples due to the difficulty of dissolving the resistate mineral phases that normally contain these elements. LASL has recently open-filed results for a large number of NTK3 quadrangles; to date analyses have been reported for about 605 of the quadrangles within the states of the Rocky Mountain region. As a result, uranium analyses am now complete for all sediment samples collected from the state of Wyoming. We have chosen to sumnarize the analytical results for Wyoming and portions of adjoining states hereafter termed "the ~ Wyoming regionn (Fig. 1 ) ; nearly 24 000 uranium analyses and nearly 17 000 analyses for 42 additional elements are available for sediment samples collected from this area. The DOE open-file report numbers are shown in Fig. 1 for reports open filed before September 1, 1980. The Wyoming region provides an ideal area for an examination of regional geochemical patterns ex- hibited by sediment samples. It is endowed with a variety of exposed geologic units and with widely distributed uranium districts associated with host units of several ages. However, discussion will focus on rock units of Eocene and Precambrian ages because they are widely exposed and host the majority of the uranium resources within the region (Fig. 2). Miocene units are also widespread and host mineralization in the Brown's Park Formation (Fig. 2). Epigenetic uranium mineralization occurs in sand- stones of lower Eocene age such as the Wasatch, Battle Springs, and Wind River Formations whereas vein type mineralization occurs in Precambrian crystalline rocks. Precambrian rocks within the region consist of a variety of granitic and meta- morphic rocks with l .4-2.8 billion year ages, except within the Uinta Arch, where they consist of a sequence of very low grade metamorphosed or unmetamorphosed 1.0 billion year old sedimentary rocks. Precambrian rocks have served as sources for much of the clastic material comprising the lower Eocene units, and may also have provided the source for the uranium in mineralized Eocene or Miocene sandstones (Stuckless, 1979). The remainder of this paper describes the relationship of elemental concentrations in HSSR sediment samples to exposures of Eocene and Precambrian rocks. The results are used primarily to determine where these Precambrian rocks might provide the most suitable uranium source areas and to infer the direction of transport toward adjacent depositional basins during the Eocene.

Jan 1, 1980

By Frank G. Breyer

C ONDITIONS have not been favorable for new developments in any line. It has been a period, how- ever in which recent developments have been subjected to the severest tests. Those which have been able to hold their own in the severe competition of 1932 must be considered fully proved commercial processes. The continuous vertical-muffle retort plant at Palmer- ton is reported to have been in operation at practically full capacity throughout the year. The high quality of metal produced and the low operating costs are factors which have kept this plant running when many of the older furnaces were shut down. The plant at Meadow- brook, W. Va., is also reported to have been in steady operation throughout the year. Average retort life is said to be better than two years with about three-quarters of the original retorts still in operation after 2 ½ years.

Jan 1, 1933

FEB. 17-The past month found the average citizen backed off just a little more into his blind corner staring glassily at hydrogen bombs, unbalanced budgets, John L. Lewis, more inflation, a rising wave of strikes, the country's only active battleship on a mudbank, a famous scientist in gaol as a traitor, a favorite actress on a Roman holiday, and rising mountains of potatoes, butter and eggs begging for destruction. About the only bright spot has been industrial activity and employment, but even these are menaced by the coal shortage. Most industries have orders on hand or in prospect to warrant high operations for some time to come. The trend of the Reserve Board's production index is upward except as strikes may interfere. There has been heavy buying at the seasonal merchandise shows, particularly in furniture and house-hold goods. The demand for goods of this kind illustrates greater confidence in the Spring outlook than was generally felt a year ago. Further, the demand also reflects improved market positions due to curtailment of output and reduction of inventories in 1949 and sustained consumer buying power. It demonstrates the strong support that is given directly to many businesses, and indirectly to all, by the phenomenal construction activity that is now under way. The Commerce Department places the number of new dwelling units started in 1949 at the new all-time high of 1,019,000.

Jan 3, 1950

By B. Hyatt, E. Klokholm

The reesistivity of Cu-Pd alloys of 9.6 to 29 pct Pd alloys was measured after plastic deformzation in tension. For all compositions a continzting decrease in resistivity with increasing plastic strain was observed. By comparison with the results of Damask on a brass ad Cu3Au, it was deduced that these anonzalous decreases in resistivity are due to the decrease in short-vunge order caused by cold work. An anomalous decrease in the resistivity of cold-worked CU-Pd alloys was first reported by Jaumot and Sawatzky.' They observed decreases in the electrical resistivity when disordered Cu-Pd alloys drawing at room temperature. Recently, a similar anomaly was reported by Aarts and Houston-Mac-Mi1lan2 in Ag-Pd alloys containing 10 to 45 pct Pd. The plastic deformation in this case was produced by tensile strain at liquid-nitrogen temperatures. For AE-Pd alloys the relative resistivity change becomes positive for tensile strains of about 20 pct.

Jan 1, 1960

By Vincent T. Ricca, Kurtis Chow

When dealing with acid mine drainage as to treatment levels, costs, and evaluation of abatement schemes, predictions of the quantity and quality of the discharges are needed. An acid mine-drainage model is presented in this paper. In essence, the model is a hybrid of computer programs for stream flow simulation and acid mine drainage. Two major aspects of the model are discussed: mine-water generation and acid-load production. The former is based on hydrologic concepts and the latter on pyrite oxidation kinetics and oxidation product removal. The total model is programmed for the high-speed digital computer. The major inputs are: climatological, basin characteristics, and mine characteristics data. By the use o f the hydrologic model the amount of water that flows through the pyritic system is determined. From this information, acid loads removed by leaching, inundation, and gravity diffusion are then predicted. The outputs from the total model are: average daily mine-water discharge, the associated acid concentration or load, plus the average daily flow in the receiving streams or at basin outlets. The capabilities of the separate models have been tested individually and the joint model has been applied to a small drift mine in southeastern Ohio.

Jan 1, 1975

Jan 1, 1922

Jan 1, 1922

By JOHN A. MALONEY

AS noted in the February issue of MINING AND METALLURGY, an advisory committee to the Museum of Science and Industry of Chicago was authorized by the Institute's Board of Directors, with W. R. Wright of Chicago, former Director of the Institute, as chairman. Since that time the committee has been undergoing organization, and held its initial meeting at the Museum offices in Chicago on April 11 and 12. Functioning as consultants to the Geology and Mineral Industries branch of this new institution, the advisory committee is aiding in building an exhibit which will tell the story of geology, mining, and metallurgy to millions of visitors a year. Although patterned to some extent

Jan 1, 1932

By Valentin R. Garfias

The world's production of petroleum during 1926 is estimated at 1,096,000,000 bbl., an increase of about 29,000,000 from that of 1925 and somewhat larger than the average during the last 4 years, which is about 1,049,000,000 bbl. The daily average during the year may be estimated at 3,000,000 bbl. of which the United States produced 2,123,000 and other countries 877,000. The outstanding developments during the year have been the decline of the Mexican fields, the counterbalancing of this decline by the increase in Venezuelan and Russian production, and increases in Roumania and Colombia. During 1926 the United States, Mexico and Russia retained their relative positions as the three leading producers, while Venezuela probably outranked Persia for fourth place, Roumania passed Dutch East Indies for sixth, and Colombia moved from sixteenth to the eleventh position. It further appears that should present conditions develop normally throughout 1927, it is not improbable that Mexico will be outranked by Russia as the second oil-producing country and that the increased yield of Colombia will place this country in the eighth or ninth position, and ahead of India. The United States and Mexico should produce in 1926 about 79 per cent. of the world's total and the aggregate of the seven leading countries should be close to 95 per cent. of the total. It is interesting to note that about 85 per cent. of the total comes from fields on the American continent, the United States accounting for about 71 per cent., and Spanish-American countries and Trinidad for 13 per cent. Production of countries other than the United States and Mexico has gradually increased during the last four years and now represents about 21 per cent. of the total. The United States easily retains its long standing leadership with a total yield of 775,000,000 bbl., or an average daily yield of 2,123,000, representing about 71 per cent. of the total, which is about equal to that of the previous year. An increase in production of about 11,000,000 bbl. is indicated by the statistics so far available. It will be noted that the American production in the last 4 years has averaged about 746,000,000 bbl. yearly and that this uniformity, as well as the marked increases

Jan 1, 1927

By AIME AIME

NO ADEQUATE salary scale, at the present time, can ignore the increase in the cost of commodities 'during the last few years or- afford to assume that this increase is merely temporary. A study of the change in prices and wages during and after the Civil War is of interest in connection with changes that have taken place from 1913 to 1919. The curves on the accompanying figure, based on reports of the War Industries Board and Department of Labor, show these changes. During the Civil War retail prices rose to 164,2 per cent. of the prices of 1860, during the next 8' or 10 years. It is interesting to note that the rise in wages during the Civil War was almost simultaneous with the rise in the prices of commodities. During the World, War, the rise in wages has lagged about a year behind the rise in prices. Furthermore, in the period immediately, following the Civil War, wages continued to rise after prices started to fall, The present price level is not considered merely temporary by such of our Government agencies as the Department of Labor and the Federal Reserve Board or by such economists as Irving Fisher' and J. S. Holden.2 Sub-

Jan 1, 1920

By P. BOURY

THIS account of a contrivance which has been found serviceable in practice may be of interest to engineers, and' especially to those engaged in hydraulic mining. In that process, one feature which seems at first sight to possess little significance, is highly important in its effects, namely, the regular supply of water to the " giants." The chief condition of this regularity is an even flow in the pipe-line from the penstock to the nozzle. This, of course, requires that the penstock be kept full. Any considerable surplus of water, overflowing at the penstock, is a simple waste, unless it be otherwise utilized in the sluices. At all events, it does not affect the delivery of the nozzles. But a deficiency at the penstock may admit air into the pipe; and this may produce hydraulic recoil, injuring the line by incessant vibrations, giving rise to leaks, and even to blow-outs, and (when a partial vacuum exists at the time of the fracture the collapse of the pipe. An accident of this sort in our main pipe-line, occasioned partly by a settling of the ground and partly by the presence of air in the pipe, led to the employment of the device here described. The line referred to is made of 30-in. pipe, successively reduced to 18 and 15 in. in diameter, for the supply of two giants. By reason of the causes above mentioned, the 30-in. pipe burst more than 1,400 ft. from the penstock, and, despite the air-valve, the 30-in. pipe was collapsed to such a degree that one length of it, next to the penstock, was squeezed together and positively swallowed by the main pipe, through which it traveled for 750 ft., piercing through a short elbow on the way. This remarkable result was undoubtedly the effect of the vacuum suddenly produced when the pipe burst.

Sep 1, 1906

By E. H. Griswold

PETROLEUM production engineering is essentially the application of the laws of 'physics and mechanics to the production of oil. A true production engineer is one who can apply the principles of mechanics, hydraulics, thermodynamics, and other physical arts so as to facilitate' the efficient and economical recovery of oil. To this end he must have wide knowledge of practical field operations and a working knowledge of geology, with a thorough understanding of the underground state of the fluids which he seeks to control. Generally speaking, there have been two schools of production engineering, the California development and the Mid-Continent development. In California the preliminary production engineering was done by representatives of the U. S. Bureau of Mines and the State Mining Bureau, and was essentially subsurface work in regard to casing patterns, water shut-offs, and completion procedure, inasmuch as these were problems of the utmost immediate importance to the California industry. The oil companies were impressed with the value of such work and placed engineers, or more strictly speaking, engineering geologists on their field staffs. These men, realizing the need of further technical study in the mechanical phases of producing operations, added mechanical and mining engineers, and out of the blend developed what is now known as a production engineer.

Jan 1, 1932