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By Harrison Schmidt

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

By Harrison Schmidt

Since the U. S. Geological Survey published the data on the Central Mining District collected by Lindgren and Gratonl and by Paige2 much new information has been obtained by development and mapping, but none of it had been published until recently when Kniffin3 published on Fierro, Lasky4 on the Ground Hog mine, Thorne5 on Santa Rita and Landon6 filed a thesis on the Fierro-Hanover-Santa Rita area at the University of Chicago. During the years 1927-1930 much of the writer's time was spent in mapping the geology and ore deposits of this district, particularly in the area of the zinc deposits at Hanover. Some of the data collected are presented here. Previous publications have been freely drawn upon and additional data used that were generously supplied by L. M. Kniffin, Wilfred Wright and Gerald Ballmer. Thanks are due Augustus Locke, Samuel G. Lasky, Kniffin, Wright and Ballmer for suggestions and critical readings of the manuscript, and to the Empire Zinc Co. (a subsidiary of the New Jersey Zinc Co.) for the privilege of publishing material compiled largely at its expense. The relation of the Central or the Santa Rita-Hanover-Fierro district to the Silver City district is shown on Paige's geologic map in the Silver City folio.7 Granodiorite porphyry and quartz-monzonite porphyry

Jan 1, 1935

By Carl H. Samans

The attention of physicists and metallurgists has been directed toward the study and explanation of the deformation textures in metals for the past 15 years. In 1920 N. Uspenski and S. Konobejewskil were first able to show that the symmetrical X-ray diffraction effects that had been previously reported by E. Hupka2 and others in metal foils were caused by a directed arrangement of the crystallites. Since then, the systematic study of textures resulting from the application of the pure forces of tension or compression to polycrystalline materials has been supplemented by many investigations on deformed single crystals, which have greatly added to our knowledge of deformation. However, despite the valuable information secured from these comparative studies only four investigations upon cold-rolled single crystals of any of the face-centered cubic metals have been reported in the literature. This lack of quantitative data is especially unfortunate because of the much greater practical significance of rolling textures and their effects in both cold-rolled and annealed materials. This investigation was undertaken for the purpose of specifying the deformation of rolled single crystals in the hope that such information might later facilitate the explanation of polycrystal-line textures. Of the four studies that have been made upon cold-rolled single crystals, only two are of any quantitative value. S. Tanaka,3 working

Jan 1, 1934

For the benefit of those of our members who are considerable holders of securities, but owing to their isolated situations are not in-close touch with the metropolitan market and current quotations, we are publishing two very interesting graphs, showing the course of the bond and stock markets in New York over a long period. These graphs are furnished through the courtesy of the financial department of the New York Tribune.

Jan 5, 1919

For the benefit of those of our members who are considerable holders of securities, but owing to their isolated situations are not in close touch with the metropolitan market and current quotations, we are publishing two very interesting graphs, showing the course of the bond and stock markets in New York over a long period. These graphs are furnished through the courtesy of the financial department of the New York Tribune.

Jan 6, 1919

By John W. Cabot

In the manufacture by the Bessemer process of soft steel suitable for rolling into fine sheets, tubes and 60 forth, a difficulty is sometimes met with, in the tendency of this kind of metal to rise violently and boil in the moulds while being cast; this results in hollow-topped ingots, and consequently in an undue amount of scrap in the subsequent rolling. It has been noticed that this peculiarity does not pertain to all pig-irons, some grades producing a blown metal which pours quietly, while others, in whatever way the blow may have been conducted, give a metal which rises in the moulds, accompanied by the evolution of large quantities of hydrogen and carbonic oxide gases, and requiring a long time to solidify. This difference in behavior has been some-

Jan 1, 1891

By Wm. Hamilton Merritt

With the exception of the Vancouver Island coal, all the western coal-fields owe their present development to the completion, in the autumn of 1886, of the Canadian Pacific railroad. While it could not be expected that a very great deal could be accomplished in three years, enough has been done to pretty thoroughly establish the coal-bearing areas and their correspondence with those which have been developed to the south of the boundary along the lines of the transatlantic railroads in the United States. This summer I visited some of the important developments in the coal areas of Washington Territory, largely with the object of being better able to appreciate the corresponding coal-bearing areas in British Columbia to the north. In Western Canada, coal-bearing rocks have been found in three zones: 1. In the plains to the east of the Rocky Mountains and in the eastern flanking ranges, the coal occurs in the Cretaceous formation (including the Laramie). 2. In the interior plateau of British Columbia, the coal is found in the Tertiary formation. 3. On the coast of British Columbia, Cretaceous and Tertiary rocks are found carrying coal, and on the Island of Vancouver the well known Nanaimo coal has been worked for years in the first named formation. In all of these zones, the coals vary from lignites up to higher grades, the factor determining quality being the amount of pressute to which they have been subjected. The intensity of this pressure is generally shown by the disturbance which the coals exhibit, and, in many cases, is almost directly in proportion to the distance of the deposits from mountain ranges. This seems to be also the opinion expressed by Mr. Bailey Willis in connection with his Census Report on the coals of Washington. It has been elsewhere stated

Jan 1, 1890

During 1918, the activities of the United Engineering Society, the Library, the Engineering Foundation, and Engineering Council Were deeply affected by the war and much important war work Was done in our building. The endowment of Engineering Foundation was increased to $300,000 by an additional gift of $100,000 from Ambrose Swasey. By bequest of Dr. James Douglas, the American Institute of Mining Engineers received an endowment of $100,000, the income of which Will be expended in the maintenance of its library (now a part of the joint library). The Library Service Bureau has gained steadily; its business for 1918 amounted to nearly $10,000. Indexing of current engineering literature has been undertaken in conjunction With the Founder Societies and the Index is being printed in their publications. This service has been extended to the Engineering Institute of Canada and the Canadian Mining Institute. The expense is borne by the Societies. In this connection the American Society of Mechanical Engineers has purchased the Engineering Index heretofore published by "Industrial Management." In June the Westinghouse and General' Electric Co. donated to the United Engineering Society their Patent Con¬trol Library of about 8000 volumes. Other noteworthy gifts Were a collection of 370 pieces relating to patent litigations, from Jesse M. Smith, and Dr. William Paul Gerhard's collection on gas engineering, transferred by the American Gas Association.

Jan 1, 1923

By Thomas Carnahan

THE mining property of the Utah Copper Co. is situated in the West Mountain mining district, Salt Lake County, Utah, in the Oquirrh Range of mountains. GEOLOGY In a general way the rock formation of the district consists of a series of beds of quartzite and limestone intruded by a body of monzonite porphyry roughly elliptical in shape, with an east-west axis over a mile in length and a north-south axis of about 3,000 ft. This porphyry intrusion, accompanied by strong mineralizing action and fracturing, resulted in the formation of orebodies in the adjacent sedimentary rocks, and was itself sufficiently mineralized to make it one vast orebody. The Utah Copper Co.'s mining property comprises within its boundaries practically the entire outcrop of the monzonite mass, of a commercial grade. GENESIS OF PORPHYRY ORE Following an intricate system of fracturing, mineral solutions circulated freely through the porphyry, depositing small quantities of copper and iron, and resulting in a considerable silicification of the monzonite. The quantity of copper originally deposited was undoubtedly too small to have ever given the porphyry a commercial value, had not secondary enrichment, due to the leaching of the copper from the surface of the mass and re-deposition in the sulphide zone, been active over a long period of years. A large portion of the leached material has probably been .removed by erosion, but there still remains a blanket of leached and oxidized porphyry of varying thickness covering the sulphide ore, known as capping. Over certain sections of the orebody, this capping contains commercial quantities of copper carbonates, but most of it contains little or no copper.

Jan 1, 1916

By Thomas S. Carnahan

The mining property of the Utah Copper Co. is situated in the West Mountain mining district, Salt Lake County;Utah, in the Oquirrh Range of mountains. Geology In a general way the rock formation of the district consists of a series of beds of quartzite and limestone intruded by a body of monzonite porphyry roughly elliptical in shape, with an east-west axis over a mile in length and a north-south axis of about 3,000 ft. This porphyry intrusion, accompanied by strong mineralizing action and fracturing, resulted in the formation of orebodies in the adjacent sedimentary rocks, and was itself sufficiently mineralized to make it one vast orebody. The Utah Copper Co.'s mining property comprises within its boundaries practically the entire outcrop of the monzonite mass, of a commercial grade. Genesis of Porphyry Ore Following an intricate system of fracturing, mineral solutions circulated freely through the porphyry, depositing small quantities of copper and iron, and resulting in a considerable silicification of the monzonite. The quantity of copper originally deposited was undoubtedly too small to have ever given the porphyry a commercial value, had not secondary enrichment, due to the leaching of the copper from the surface of the mass and re-deposition in the sulphide zone, been active over a long period of years. A large portion of the leached material has probably been removed by erosion, but there still remains a blanket of leached and oxidized porphyry of varying thickness covering the sulphide ore, known as capping. Over certain sections of the orebody, this capping contains commercial quantities of copper carbonates, but most of it contains little or no copper.

Jan 1, 1916

By K. D. Eigenbrod

A case history is presented of a landslide that occurred adjacent to a highway in the valley of the North Saskatchewan River, about 12 miles upstream of Edmonton, Alberta. The slide took place in the late fall of 1965 following excavations associated with highway improvements that deepened the slope and cut it back to 20º. The slide occurred in the Upper Cretaceous Edmonton Formation. Till covers the bedrock at the location. The bedrock consists of interbedded mudstone, claystone, and sandstone with layers of bentonite and coal. The field investigation consisted of a series of pits at the toe of the slide and seven boreholes around it. Undisturbed samples were taken with a Pitcher Sampler and piezometers were installed at various depths in the section. The slide had taken place on a horizontal bentonitic clay layer and it crossed softened mudstone in the back slope. Three piezometric levels were detected but no water pressures were found along the horizontal portion of the slip surface because it was in contact with a free-draining coal layer. Borehole evidence revealed that the bentonitic clay layer was sheared in place beyond the confines of the slide zone. Although this slide was a first-time occurrence, it was part of a much larger slide block that moved presumably when the valley was being formed. Laboratory tests were carried out to determine the shear strength parameters of the bentonitic clay and the back slope material. These parameters together with the observed water pressure distribution in the slide area gave a factor of safety of 1.01 in a non-circular limiting equilibrium analysis. The case history is particularly instructive in indicating the care that must be taken to obtain representative information for stability analysis when geological and groundwater conditions are non-uniform. The origin of the sheared clay is discussed.

Jan 1, 1972

CHARLES KIRCHHOFF, Chairman. ALBERT SAUVEUR, Vice-Chairman. HERBERT M. BOYLSTON, Secretary, Abbot Bldg., Harvard Sq., Cambridge, Mass. John Birkinbine, J. E. Johnson, Jr., J. S. Unger, William H. Blauvelt, William Kelly, Felix A. Vogel, James Gayley, Richard Moldenke, Leonard Waldo, Henry D. Hibbard, Joseph W. Richards, William R. Walker, Henry M. Howe, C. F. W. Rys, William R. Webster, Robert W. Hunt, E. Gybbon Spilsbury, Frederick W. Wood. A. A. Stevenson, J. S. Unger and C. F. W. Rys have accepted membership on the Iron and Steel Committee. The Program Committee has held two meetings- in New York and has perfected the preliminary plans for the October meeting. The Committee will meet again in September. The following provisional program has been laid out by the Program Committee, but is subject to later additions and changes :

Jan 9, 1913

By L. M. Clarebrough, A. K. Head, G. W. West, M. E. Hargreaves

RECENTLY Welber and Webelerl reported that during the annealing of fatigued copper no energy was released, but that energy was absorbed in the range of temperature 250" to 400°C. In view of the fact that strain hardening occurs during the fatigue of copper, this result was surprising and it seemed desirable to check the measurements. This note describes measurements made by a different technique which indicates that energy is stored during the fatigue of copper. Two test bars with gage length ¾ in. in diameter and 6 in. long were machined from OFHC copper and annealed in vacuum for 1 hr at 600°C. These were fatigued to fracture in an Avery pulsator at a frequency of 2000 cycles per min. The first specimen fractured after 0.25x10 cycles under a push-pull

Jan 1, 1956

By Ronald J. Roman, Craig Olsen

Alterations were performed on a previously developed heap leaching model representing sulfuric acid solution leaching of a malachite sandstone ore. The alterations were made in order to approach a more realistic solution to the leaching equations used in the model and to provide a means of obtaining a constant acid con- centration in the model' s simulated heap effluent solutions. This constant acid concentration is desired if the effluent solutions are to be treated in a solvent extraction-electrowinning plant. An economic study was made showing a use of the leaching model for an imaginary heap leach operation. The example illustrates a method of selecting heap leaching parameters if data are available on mining costs, dump costs, capital cost, etc. This was achieved using an incremental investment technique.

Jan 1, 1974

By C. G. Dunn, J. L. Walter

SILICON-iron .under certain conditions of processing and annealing will form a cube texture. The occurrence of this texture in thin tapes of silicon iron was first reported by Assmus, Detert, and Ibe.' They concluded that the cube texture in their material formed by a secondary re crystallization process. In the course of present investigations on the development of the cube texture and the mechanisms involved in its formation by secondary re-crystallization it was found that under certain conditions the cube texture was replaced by a cube-on-edge or (110) [001] texture. We call this phenomenon tertiary re crystallization since it follows secondary recrystallization. The secondary recrystallization occurs after primary recrystallization and a substantial amount of normal grain growth. It is the purpose of this paper to describe briefly the occurrence of tertiary recrystallization and the structure and texture prior to and after tertiary recrystallization. The primary and secondary recrystallization structures and textures are the subject of another study and will be referred to briefly in the discussion of results. Evidence will be presented for the view that the dominant driving force for tertiary recrystallization is derived from the surface free energy which depends on the crystallographic planes presented to the gas-metal interface. In the absence of boundary restraining forces (dispersed phases, thermal grooves, and so forth) a sufficiently large difference in surface free energy across a grain boundary would produce boundary migration away from the center of curvature of the boundary intersection line in the surface of the sample according to risher.2 Therefore, particular attention was paid to observation of the direction of motion of these surface boundary lines. Furthermore, measurements of the actual boundary curvatures could be used to estimate the driving force supplied by surface free energy. EXPERIMENTAL PROCEDURE Samples were prepared by hot and cold-rolling vacuum-melted ingots of iron containing 3 pct Si to strips 0.012 and 0.006 in. thick. The ingots contained less than 0.005 wt pct impurities. The rolled strips were cut into samples approximately 1 in. wide by 3 in. long and were electropolished to remove surface imperfections. All samples were annealed in a vacuum at a pressure of approxi-

Jan 1, 1960

By H. Gisser

Recent experimental work has demonstrated (1)2 that ammonia and oxides of nitrogen are formed during the aging of smokeless powder. This is significant in connection with the problem of "season cracking," or stress corrosion of brass cartridge cases in view of other work(1) indicating that stressed and "stress- relieved" cases stored with small quantities of added ammonium nitrate crack on firing. The deterioration of stressed brass by ammonia has been known for some time(z) and it appears therefore that stress- corrosion cracking of brass cartridge cases is intimately associated with the so-called "powder volatiles," ammonia and oxides of nitrogen, both of which are decomposition products of smokeless powder. Working on the hypothesis that any barrier which prevents the powder volatiles from reaching the brass surface will reduce the incidence of stress-corrosion cracking, it was considered desirable to investigate the use of organic resin films to accomplish this purpose. The possibility of formation of ammonia within the nitrocellulose powder charge and by reduction of nitrogen oxides on the surface of the brass case requires that the barrier film be resistant both to ammonia and oxides of nitrogen. The film must also be impermeable to ammonium salts, either solid or in solution, since these salts and water necessarily appear within the powder charge. The usefulness of the

Jan 1, 1945

By S. R. Elliott

The Spies mine is located in the eastern half of the northwest quarter of section 2443-35, near the village of Iron River, Mich., and is operated by The Cleveland-Cliffs Iron Co. Speaking generally, the jasper hanging walls of most of the deposits in the Iron River district dip at a steep angle and are exceedingly strong, standing without caving, even after mining has been continued for years and after large excavations have been made. The ore is fairly hard and tough and contains no slippage faces. It occurs in large masses, which are often egg shape, with the smaller end down, and can be mined in open stopes without the use of timber. The common system employed in the district is the shrinkage stope, or some modification of it. The Spies system was developed to utilize the advantages of the open-stope method and to avoid the disadvantages of the shrinkage stope. The Spies shaft was sunk to such a depth that the bottom, or third level, was in rock at a short distance below the bottom of the orebody, the shape and extent of which had been previously determined by diamond drilling. This is shown in plan and by the ore contours at the first, second, and third levels in Fig. 1, and in section in Figs. 2 to 7. In order to provide the necessary mills and raises, three parallel crosscuts were driven on 25 ft. centers on the bottom level. Drifts on the second and first levels were driven to the orebody and followed the foot wall in a southerly direction to the end of the ore. In crosscut 3, Fig. 1, raises 30, 40, 50, and 60 were carried up on the foot wall and holed into the second level, and were ultimately carried up and holed into the first level. These foot-wall raises carry the pipes and ladders, provide a means of ventilation, and furnish safe communication to all working places in the stope. From crosscuts 1, 2, and 3, raises were completed to a height of 32 ft., or the elevation of the first sublevel. They were then connected by east and west crosscuts to the main foot-wall raises 30, 40, 50, and 60, shown in Fig. 4. The crosscuts in raises 1 to 5 were then driven west and the

Jan 1, 1923

By S. R. Elliott

The Spies mine is located in the eastern half of the northwest quarter of section 2443-35, near the village of Iron River, Mich., and is operated by The Cleveland-Cliffs Iron Co. Speaking generally, the jasper hanging walls of most of the deposits in the Iron River district dip at a steep angle and are exceedingly strong, standing without caving, even after mining has been continued for years and after large excavations have been made. The ore is fairly hard and tough and contains no slippage faces. It occurs in large masses, which are often egg shape, with the smaller end down, and can be mined in open stopes without the use of timber. The common system employed in the district is the shrinkage stope, or some modification of it. The Spies system was developed to utilize the advantages of the open-stope method and to avoid the disadvantages of the shrinkage stope. The Spies shaft was sunk to such a depth that the bottom, or third level, was in rock at a short distance below the bottom of the orebody, the shape and extent of which had been previously determined by diamond drilling. This is shown in plan and by the ore contours at the first, second, and third levels in Fig. 1, and in section in Figs. 2 to 7. In order to provide the necessary mills and raises, three parallel crosscuts were driven on 25 ft. centers on the bottom level. Drifts on the second and first levels were driven to the orebody and followed the foot wall in a southerly direction to the end of the ore. In crosscut 3, Fig. 1, raises 30, 40, 50, and 60 were carried up on the foot wall and holed into the second level, and were ultimately carried up and holed into the first level. These foot-wall raises carry the pipes and ladders, provide a means of ventilation, and furnish safe communication to all working places in the stope. From crosscuts 1, 2, and 3, raises were completed to a height of 32 ft., or the elevation of the first sublevel. They were then connected by east and west crosscuts to the main foot-wall raises 30, 40, 50, and 60, shown in Fig. 4. The crosscuts in raises 1 to 5 were then driven west and the

Jan 1, 1923

By J. B. Evans

Maintaining overall optimum profitability at a mine site necessitates constant reassessment of operating strategies. In essence, each strategy is a particular combination of envisaged capital expenditure, income flow and elapsed time. Selecting a strategy, based on profita¬bility potential requires each contemplated strategy being subjected to discounted cash flow analysis; even with a computer such analysis can be cumbersome. The chapter discusses a 'shortcut' technique which assigns profitability rankings to alternate strategies and iden¬tifies those aspects of a. strategy which impact heavily on profitabil¬ity. This technique can yield quick assessments of sufficient accuracy for many operating strategy decisions. taken on site at on-going mines.

Jan 1, 1978