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By C. R. Austin

THE paper describes an investigation on the pressure welding of low-carbon steels. The work necessitated a reproducible mechanical means of making the weld and also a test that would indicate the nature and completeness of the union. An apparatus including a high-temperature furnace was devised for making the welds, and the ordinary tensile pulling test 'in correlation with macroscopic and microscopic observations was used as a means of examining the result. Initially it was intended to devise some simple test of weldability, but as the experimental work progressed, it soon became clear that with our limited knowledge of the exact nature of the mechanism of pressure welding it was impossible to interpret our results or to devise a simple test of weldability. Hence it was manifestly necessary first to study the mechanism of such welding and attempt to elucidate the fundamentals underlying the so-called welding of steel by pressing together two metal surfaces. It also became evident that it was necessary to define the term "welding." In many early experiments when, two heated rods were pressed together and then pulled in the cold, very high tensile values were obtained, and yet the fracture took place exactly in the line of junction except for a few small scattered areas. In other words, the' rods pulled apart just as they were before being "stuck" together and had certainly not welded completely, despite the high value indicating the strong cohesive force operating. In this paper, welding has been considered as a form of intimate contact between two metal surfaces, so that the units lose their individual identity and there is no change in physical properties in passing through the weld from one unit to the other. This is defined as "true welding." When true welding has taken place completely over the whole section, the probability is that the rupture in tensile test will occur outside the weld.

Jan 1, 1932

By R. A. Salathiel, A. D. Kaiser, P. H. Monaghan, B. E. Morgan

The productivities of many hydrocarbon-bearing for-rnntions appear to be reduced during drilling, completing and repairing operations. The reason for these othcarwise unexplainable low productivities may be a drastic reduction of formation permeability immediately surrounding the borehole. A possible cause of the reduced permeability is swelling and dispersion of clays present in porous media when contacted by fresh water or mud filtrates. Hence, the invasion of fresh water or mud filtrate into hydrocarbon-bearing formations that contain clays may cause low productivities as a result of formation damage. Present laboratory investigations have yielded results which supplement existing literature on formation damage. An expanded-type clay, montmorillonite, way found in hydrocarbon-bearing formations not previously analyzed. When sand columns and formation cores containing montmorillonite were contacted by fresh water, their oil permeabilities were reduced. This reduction in oil permeability way restored partially but not completely by a repair procedure, i.e., flooding with kerosene containing organic agents or flooding with water containing electrolytes. Hence, where montmorillonite is present in formations, prevention of formation danzage was indicated to be the only complete solution to the problem. To prevernt formation damage, results suggested use of an approximately 1 per cent solution of calcium chloride or stronger solutions of sodium or potassium chloride. In conventional rotary drilling operations the wall of the hole is exposed to drilling mud for days, weeks, and in some instances for as long as several months. During this time, drilling mud filtrate seeps slowly into formations surrounding the hole. The permeability and stability of many formations, especially those containing clayey materials, are impaired by the mud filtrate. Often interaction between the mud filtrate and the formation causes drilling and production difficulties. Serious reduction in productivity of oil and gas formations during drilling, completing and repairing wells has been noted often in recent years. Cases are known of development wells which produced only small volumes of fluid upon completion. However, after a period had elapsed, they began to produce oil or gas in commercial quantities. In other cases, results of drill-stem tests taken during the drilling of deep wells have indicated good production should be obtained from shallow formations. Later difficulty has been experienced in obtaining production from these shallow formations which had remained in contact with drilling muds for an extended time. In yet other cases wells have failed to attain the productivities expected from previous performance after the use of drilling mud as a circulating fluid during workover operations. It is evident from the field behavior cited that the productivities of certain oil- and gas-bearing formations have been damaged by exposure to drilling muds. This reduction in well productivity, called "formation damage", causes serious consequences. In development wells, expensive remedial operations are incurred. In wildcat wells, good formations may appear to be marginal or even non-productive. The importance of formation damage has been recognized by a number of investigators1-s who have considered the effects of fresh water, saline solutions and aqueous mud filtrates on the permeabilities of formations. A general conclusion from such studies is that interaction between water and formation clays reduces permeability of reservoir rock and that the permeability decreases as salinity of the water decreases. Data in these references, however, concern the permeability change with only a single fluid present. A more pertinent and direct consideration in the production of oil and gas from wells is the permeability change when two fluids, oil and water, are present. Recognizing this, Nowak and Kreuger2 and Bertness1" considered several ways in which mud filtrates and saline solutions caused reductions in the oil permeability of formation cores. Investigations discussed here were designed to supplement information in the literature on changes in oil

By AIME AIME

TEXAS not only produces millions of barrels of petroleum daily, but supplies the oil industry with an asset infinitely more valuable than liquld gold. That asset is leadership. The oil industry was built from its humble beginning a few decades ago into a potent force in world economy by human hands and human brains. One of these great leaders in the busy world of oil is Wallace Pratt, of the Humble company, who has been called to a position as director and member of the executive committee of the Standard Oil of New Jersey. So reads the Houston Post of June 3, 1937.

Jan 1, 1944

The Sub-committee on Safety of the Industrial Organization Com-mittee of the Institute has been asked to cooperate with the National Safety Council, and has made certain recommendations to the Board of Directors of the Institute regarding ways and means of bringing about this cooperation. The National Safety Council has been in existence seven years. Its inception was at a meeting of the American Iron and Steel Electrical Engineers held in Milwaukee in 1912. The first annual congress was held in New York City in October, 1913, at which time the Council was definitely organized. Its membership now consists of nearly four thousand members, representing industrial plants, railroads, public utility companies, insurance companies, state labor commissions, Chambers of Commerce, manufacturers' organizations, etc. These members are in all states of the Union and in eleven foreign countries, and through them the National Safety Council reaches more than six million workers.

Jan 7, 1919

By R. M. Brick

THE Institute of Metals Division Lecture in 1936, given by R. F. Mehl, on diffusion in solid metals1, was introduced with the statement that "the phenomena of diffusion are intimately related to many basic prob-lems of the metallic state, but in addition to this the process of diffusion is of first importance practically." In view of the scope of that lecture, it does not seem necessary to review the importance, history or present status of diffusion problems. One aspect of the subject of diffusion that has received little attention became of some immediate importance in the course of a study on segrega-tion. When a solid solution alloy freezes, the familiar mechanism of solidification requires that the first nuclei formed be low in solute con-centration, with a resultant normal segregation or coring effect during freezing. Theoretically, diffusion of solute atoms during solidification should result in a homogeneous solid solution. Actually, of course, it is impossible in most binary alloys to obtain a cooling rate that will permit diffusion to eliminate coring in the freezing dendrites. For a given alloy, the extent of diffusion attained up to the point of final solidification will determine the degree of enrichment in solute atoms of the final liquid phase. The flow of this liquid into dendritic contraction channels and the solute concentration of the liquid seem to be the determining factors as to whether the final gross segregation is normal, inverse or absent. The purpose of the present study of diffusion was to determine to some extent the separate diffusion rates of copper and magnesium into pure aluminum with a view to clarifying previous results on segregation in these alloys; i.e., the fact that under similar freezing conditions alumimum-copper alloys segregate inversely and aluminum-magnesium alloys segre-gate normally. Of concomitant interest were the questions of the homogenization times required for segregated ingots or partially melted, i.e., "burnt," structures, and the solution heat-treatment times required for cast, hardenable aluminum-copper and aluminum-magnesium alloys, for worked and annealed structures, and so forth.

Jan 1, 1937

By John Richards

MY remarks will be confined to the experience of our company in mining the No. 8 seam of coal in Ohio, although I believe that the relationship existing here between the method of mining and the method of cleaning will hold true in many of the coal seams throughout the country. The increasing demand for a cleaner and better graded product is being felt throughout the entire coal industry, and the methods of mining are playing an important part in the control of various sizes and quality of coal produced. We have found a definite relation between the mechanical loading of coal and its preparation for the market. In the No. 8 coal seam the location of the non-combustible material is regular. The' marketable coal lies in three benches, separated by streaks or bands of impurities. These impurities must be removed from the coal to properly pre pare the product for the market. Where hand-loading methods are employed, the loader removes as much of this non-combustible material as possible at the working face. The impurities that are missed by the loaders are removed as the coal passes through the preparation plant, by means of picking tables. As this method of cleaning cannot improve the quality of the extremely fine sizes, a practice has been established in the company's hand-loading mines, of undercutting the coal about 2 in. above the bottom of the seam, thereby eliminating any possibility of impurities caused by the cutting machines cutting into the rock bottom below the coal seam.

Jan 1, 1934

By Ivan B. Cutler, Milton E. Wadsworth

Coprecipitation of anionic and cationic polyelectrolytes has been applied to flocculation of several mineral systems. Results obtained in a study of the flocculation of kaolinite and hematite suspensions of polycationic and polyanionic electrolytes are presented. Greatly increased settling rates were observed following precipitation of positive and negative polyelectrolytes on the surface of finely divided minerals in aqueous suspension. The ratios of polycationic to polyanionic electrolytes required to produce maximum sedimentation have been shown to correspond closely with the equivalence points obtained by light scattering studies of systems containing the positive and negative polyelectrolytes by themselves.

Aug 1, 1956

By Herbert Hoover, Harlod Washburn

This paper is in the nature of a rough preliminary report on the progress that has been made in the application of the mass spectrometer to various problems arising in the petroleum industry. A few years ago the authors considered a number of the problems that were arising in the qualitative and quantitative measurement of small amounts of hydrocarbons. The methods available of making analyses by chemical techniques appeared to leave much room for improvement. Without going into the reasons at this point, attention was turned to the possibility of employing physical instead of chemical methods of accomplishing the desired results. A preliminary investigation disclosed that the mass spectrometer presented a possibility of solving many problems which could not easily be accomplished by other methods. Work was begun in developing the necessary apparatus and technique. A great deal of encouragement and many valuable suggestions were received from Dr. Robert A. Millikan, Dr. W. R. Smythe, and Dr. W. N. Lacey, of the California Institute of Technology, and from Dr. E. 0. Lawrence, who recently received the Nobel Prize, of the University of California. The authors particularly wish to acknowledge the very great willingness of these outstanding scientists to be helpful in solving many of the problems that were involved. So far as the authors are aware, this was the first application of the mass spectrometer to commercial work. The results were considerably better than had at first been anticipated. Briefly, it is possible to run a qualitative and quantitative analysis of an unknown mixture of hydrocarbon gases, with an accuracy of better than plus or minus 5 per cent of each of the various constituents. An exceedingly high degree of sensitivity has been obtained, and a relatively short time is required to complete an analysis. Furthermore, it is unnecessary to separate a mixture of gases into its various components in order to complete the analysis. The Mass Spectrometer The mass spectrometer should not be confused in any way with the optical 01 grating type of spectrograph now in general use. The operation of the mass spectrometer is entirely different in principle and bears practically no resemblance to the optical or grating instruments. The original conception and development of the mass spectrometer dates from and is generally credited to Aston, of Cambridge, England. An early accomplishment of his research, about 20 years ago, was the discovery that the inert gas neon was actually a mixture of two kinds of atoms, one of the atomic weight 20 and the other of atomic weight 22. These two components occurred mixed in such proportion as to yield the usual atomic weight of 20.2. The study was continued and most of the elements were shown to be mixtures of components whose atomic weights can, to in

Jan 1, 1941

By Harlod Washburn, Herbert Hoover

This paper is in the nature of a rough preliminary report on the progress that has been made in the application of the mass spectrometer to various problems arising in the petroleum industry. A few years ago the authors considered a number of the problems that were arising in the qualitative and quantitative measurement of small amounts of hydrocarbons. The methods available of making analyses by chemical techniques appeared to leave much room for improvement. Without going into the reasons at this point, attention was turned to the possibility of employing physical instead of chemical methods of accomplishing the desired results. A preliminary investigation disclosed that the mass spectrometer presented a possibility of solving many problems which could not easily be accomplished by other methods. Work was begun in developing the necessary apparatus and technique. A great deal of encouragement and many valuable suggestions were received from Dr. Robert A. Millikan, Dr. W. R. Smythe, and Dr. W. N. Lacey, of the California Institute of Technology, and from Dr. E. 0. Lawrence, who recently received the Nobel Prize, of the University of California. The authors particularly wish to acknowledge the very great willingness of these outstanding scientists to be helpful in solving many of the problems that were involved. So far as the authors are aware, this was the first application of the mass spectrometer to commercial work. The results were considerably better than had at first been anticipated. Briefly, it is possible to run a qualitative and quantitative analysis of an unknown mixture of hydrocarbon gases, with an accuracy of better than plus or minus 5 per cent of each of the various constituents. An exceedingly high degree of sensitivity has been obtained, and a relatively short time is required to complete an analysis. Furthermore, it is unnecessary to separate a mixture of gases into its various components in order to complete the analysis. The Mass Spectrometer The mass spectrometer should not be confused in any way with the optical 01 grating type of spectrograph now in general use. The operation of the mass spectrometer is entirely different in principle and bears practically no resemblance to the optical or grating instruments. The original conception and development of the mass spectrometer dates from and is generally credited to Aston, of Cambridge, England. An early accomplishment of his research, about 20 years ago, was the discovery that the inert gas neon was actually a mixture of two kinds of atoms, one of the atomic weight 20 and the other of atomic weight 22. These two components occurred mixed in such proportion as to yield the usual atomic weight of 20.2. The study was continued and most of the elements were shown to be mixtures of components whose atomic weights can, to in

Jan 1, 1941

By A. A. Terchick, J. C. Anderson, D. T. King

During 1972-1973, U.S. Steel acquired an existing southern West Virginia high volatile coal mine property including a 150 tph heavy media feldspar jig preparation plant. Expansion of production from the property required an increase in plant capacity to 300 tph, replacement of the feldspar jig with a hydrocyclone circuit, and inclusion of a water clarification thickener system. The rugged and restrictive nature of the terrain adjacent to the plant facility indicated prohibitive construction costs and severe site congestion would be encountered if a conventional water clarification thickener were installed. A high-loading, small-volume thickener, developed initially for the sugar beet industry by the Enviro-Clear Co. of New York, was investigated by U.S. Steel Research for possible coal preparation application, utilizing bench scale and small scale pilot plant evaluation methods. Results of testing at existing U.S. Steel preparation plants indicated predictable successful application of the Enviro-Clear thickener, so a 35-ft-diam unit was installed. The two-phase thickener system, utilizing presettled bottom sludge as a filter-clarification media, has successfully performed since commissioning in April 1973, producing clarified water competitive with conventional thickener systems with freedom from usual thickener operational problems.

Jan 1, 1976

By Archer E., Wheeler

Producing copper companies were active during 1941 owing to the national defense program the United States and the requirements of the friendly belligerent nation. This activity extended to the American owned properties in South America, the major part of whose product was taken by the Metals Reserve Co., a U.S. Government agency. Anaconda Copper Mining Co. is building a new converter plant at Anaconda, with four units of the Peirce-Smith type. The addition is being built adjacent to the reverberatory plant so as to avoid the necessity of hauling matte and slag. It is expected to be completed this year.

Jan 1, 1942

By Minoru Yamada, Eikichi Mohri

INTRODUCTION Most of the copper concentrates treated by the flash smelting furnace at Kosaka smelter come from "black ore" that is produced in the local mines nearby. The copper concentrates contain various impurities such as lead and zinc as shown below. [ ] These impurities are mainly concentrated into the flue dusts in the copper smelting system. The dust production rates of flash smelting furnace and converter at Kosaka smelter are, therefore, fairly high compared with other copper smelters. However, by recovering these valuable metals in the dusts systematically, profit-increase of the by-products must be expected. This also leads to the solution of environmental pollution problems and enables us to establish the technical completion of complex sulfide ore treatment by flash smelting process. HISTORY OF DUST TWATMENT AT KOSAKA SMELTER 1) December in 1967 to January in' 1969 Since the flash smelting furnace started its operation in December 1967, all the dusts from the furnace had been recycled. Only conver-

Jan 1, 1976

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Advertising Manager for Machinery Manufacturing Company. Must have technical training. No. 94. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, technical graduate in Mining, Chemistry and Metallurgy, Post-graduate, Royal School of Mines, Freiberg, Saxony, Germany and Columbia School of Mines. Aged 37, 14 years' experience in teaching mining metallurgy, chemistry and assaying. Available now. Willing to go anywhere. No. 278. Member, aged 33, mining engineer, 88 years' experience, desires position as mine safety and efficiency engineer with coal company. Best of references on request. No. 290.

Jan 5, 1916

By Walter A. Backofen, Donald H. Avery

Intense primary and cross-slip traces were observed in easy glide on Cu: 6 pct-A1 single crystals deformed in tension. A mechanism of cooperative source operation is developed which recognizes that both the applied stress and that resolved from dislocation arrays contribute to the stress on a source. By considering the stress from arrays, the activation of secondary systems in easy glide and the difference in appearance of slip markings on pure and solid-solution crystals are explained. Furthermore the cross-slip system is predicted to be second favored during easy glide for a large range of orientations. FROM many studies of easy glide in fcc metal crystals, a pattern of observations has developed which still requires full explanation. In pure copper, aluminum, and silver, the easy-glide, slip traces are fine and uniform with steps 50 to 100A on the primary* system.1-4 Yet it has not been at all clear why slip in the pure materials should occur in this way. On the contrary, one might expect, with simple slip and a low hardening rate, that the weakest sources on the primary system would operate extensively to produce strong slip traces. In a brass, however, intense slip steps up to 0.5 are found on both primary and cross-slip system4,6-9 seeger10 has pointed out that in a material of low stacking-fault energy such as a brass, extensive easy-glide cross-slip could not be thermally activated, but rather must originate on the cross-slip plane. In further explanation, the wilsdorfs4 and seeger10 noted that only the cross-slip system would not harden differently than the primary, whatever the latent hardening tendencies of other systems; therefore, in brass, which exhibits high latent hardening, the cross-slip is the only secondary system which could be expected to operate extensively, once it became active. The explanation of how the cross-slip system, on which the applied stress is low, becomes activated has been related, in a nonspecific way, to pileups by Hirsch11 and Honeycombe.l2 In the work to be described, deformation traces on solid-solution Cu: 6 pct A1 single crvstals were studied with conventional light microscopy and a mechanism proposed to explain both the observed activation of secondary systems in easy glide and the difference in appearance of slip markings on pure and solid-solution crystals. EXPERIMENTAL In preparing the Cu-A1 single crystals, rectangular bars approximately 0.4 in. by 0.4 in. by 6 in. were first machined from ingots made by vacuum melting copper of 99.999 pct and aluminum of 99.99 pct purity. They were then packed in powdered graphite and the crystals grown in a modified Bridgman apparatus at a rate of 5 mm per hr under an atmosphere of purified nitrogen. Crystal perfection as indicated by Laue back-reflection spots was good except for the last inch to freeze, which was discarded. Orientations so determined are shown in Fig. 1. Tensile specimens with a reduced gage section were obtained by masking the ends with electrical tape and chemically polishing in a solution of 20 pct HNO3, 24 pct HAc, 52 pct H3PO4, 2 pct Hcl, and 2 pct H20 at room temperature.13 Finally, the specimens were electropolished in a 30 pct ortho-phosphoric acid bath at 12 v. Tensile deformation was performed in an Instron testing machine at a strain rate of approximately 1 pct per min. During easy glide, extensive cross-slip was observed with all crystals, in spite of the low Schmid factor on this system, and in no case was any other secondary trace encountered. A certain sequence of slip-line development was associated with the extension. At yielding, intense primary traces passing completely through the crystal developed at some point on the gage section, generally near the grips; weak cross-slip traces also appeared, extending from the primary traces into the adjacent undeformed crystal, Fig. 2. Further extension led to primary traces adjacent to the first-formed and connecting with those of the cross-

Jan 1, 1963

By William P. Prof. Blake

WHEN we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liege, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a, model for such undertakings. It is known as "Hotel Louise," this being the name of Madame d'Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

Jan 1, 1875

By William P. Blake

When we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liège, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a model for such undertakings. It is known as ((Hotel Louise," this being the name of Madame d' Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

By F. A. Jerabek, H. L. Hartman

This study presents results of investigations in a small model of segregation in discharged fill slurry, the quantity of solids escaping in the drain liquid, and the relationship of solids to slurry concentration and discharge rate. Compressibilities of fine fill material, in dry and wet states and individual size fractions, are compared. Two terms are frequently used in describing the hydraulic placement of fill material underground: hydraulic stowing is mostly associated with the underground flushing of coarse-sized fill material, such as coal washery refuse; while hydraulic backfilling refers to placement of small-sized fill material, e.g., sand or classified mill tailings, mainly in metal mines. Characteristically, in backfilling, only a few hours may elapse between the time the material is hoisted as ore and redeposited as fill underground. Hydraulic filling was first used about 100 years ago to control subsidence in coal mines. It was subsequently adopted in many mining operations all over the world, but its basic concepts have never been adequately studied and analyzed. This is not surprising, when one considers the number of variables involved in the hydraulic backfilling operation. Recently, much work has been done on the problems of transportation of slurries in pipes. Comparatively less research work has been done concerning the physical properties of fill material (compressibility, cementation, permeability, etc.). Very little work has been done on the problems of fill placing, distribution, and segregation of fill material discharged in the mine void. It is the purpose of this paper to explore two of the basic, lesser known aspects of filling: segregation and compressibility in discharged fill slurry. Difficulties in observing the behavior of hydraulic fill slurry during the pouring operation underground, and insufficient knowledge to conduct any kind of meaningful theoretical analysis, suggest experimental model studies. The tests described in the following sections were conducted in the Rock Mechanics Laboratory of the Department of Mining at Penn State.

Jan 1, 1965

By Ferdinand S. Ruttmann

The Tilly Foster iron-mine is situated in the southeastern part of Putnam County, New York, about fifty miles north of New York City, on the line of the New York City and Northern Railroad. There are a number of deposits of magnetite scattered throughout the county, the most important being those known as the Tilly Foster, the Mahopac, and the deposits of the Croton Magnetic Ore Company. (See the paper of Mr. Wendt, Transactions, xiii., 478.)

Jan 1, 1887

The Colorado Scientific Society, Denver, Colo Charles Henderson, President, 519 U. S Custom House, Denver, Colo. Beginning in 1882, up to. about 1919, the Society published 11 volumes containing many valuable papers From the informa¬tion at hand, the papers in those volumes are now only available in libraries or on file at institutions. Vols 12 and 13 are the current volumes, and the list of the geologic papers contained in them are given here For any information as to price and availa¬bility, address the above. Vol 12 (1929-31) No 1, The geology of the Sangre de Cristo Mountains, by J H Johnson, 2, Relation of the ore deposits of the southern Rocky Mountain region to the Colorado Plateau, by B S Butler; 3, Mosquito Range and the Leadville district, by C H Behre, Jr , 4, Geologic history of the Front Range, by T S Lovering, 6, Revision of geologic structure and stratigraphy in the Ouray district, by W S Burbank, 7, Localization of ore in the schists and gneisses of the Mineral Belt of the Front Range, by T. S. Lovering, 8, Relation of the ore deposits of the southern Rocky Mountain region to the Colorado Plateau, by J. B. Tenney; 9, Preliminary geologic map of the Alma mining district, by Q D. Singewald and B S Butler, 10, The Climax molybdenum deposits of Colorado, by B S Butler and J W. Vanderwilt, 12, Localization of ore bodies at Rico and Red Mountain, by G. F Collins, and Geology of Mount Lincoln and Russia mines, by Q D Singewald and B S. Butler. Vol 13 (1932- ): No. 1, Preliminary geologic notes on Galena Mountain, by J. W Vanderwilt, and High plains of Colorado and New Mexico (Late Tertiary history), by F. M. Van Yuyl and J M. Coke

Jan 1, 1933

The State Mining Bureau of California under the direction of Fletcher Hamilton, State Mineralogist, is starting a field campaign to report on the economic minerals of California, which have an important industrial and military bearing on the present war situation. Particular interest and value attaches at the present moment to our available supplies of chrome, coal, iron, magnesite, manganese, molybdenum, quicksilver and tungsten. Trained geologists and engineers of the Bureau's staff are being sent, out to obtain information with relation to the latest developments. Advance notices will be sent to the local newspapers, from time to time, of the arrival of the engineers in the various districts. All persons interested in the minerals mentioned are earnestly urged to cooperate with the State Mining Bureau by meeting the field men while in their districts or by communicating direct with the State Mineralogist at his office in the Ferry Building, San Francisco. The State Mining Bureau has just issued Bulletin No. 72 on The Geologic Formations of California. It was written by Prof. James Perrin Smith of Stanford University, and contains a complete bibliography and resume of all of our present knowledge relative to the geological formations occurring in California. It also contains much previously unpublished data, and six tables showing geologic columns. It covers 41 pages.

Jan 6, 1917