Search Documents

By Sherwin F. Kelly

MANY baffling problems of crustal geology-of warping and folding, elevation, subsidence, and great dislocations of the earth's surface-may now be on the verge of yielding to the science of geophysics. Electric, magnetic, gravitational, geothermal, and seismic methods are being turned to the gathering of geological evidence buried by deep layers of rock, or lying beneath the waters of the oceans. In this hope, B. L. Miller expresses the opinion that these geophysical studies will sup- ply useful data bearing-on some of the more theoretical problems of North American geology. Among these for example, is the explanation of how Appalachia disappeared. This ancient land mass is supposed to have foundered beneath the Atlantic Ocean after the close of the Paleozoic era and the question arises, was it warped or faulted downward? The geophysical data, though meagre, indicate that the surface of the dense, basal rocks, the probable remnant of ancient Appalachia now underlying the Continental Shelf, slopes downwards to a depth of some two miles below sea level at a distance of 140 mi. from shore: thus suggesting that the subsidence was the result of warping downward rather than abrupt faulting.

Jan 1, 1938

At its meeting on February 21, 1933, the Board of Directors the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated:

Jan 1, 1936

At its meeting on February 21, 1933, the Board of Directors the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated:

Jan 1, 1934

At its meeting on February 21, 1933, the Board of Directors the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated:

Jan 1, 1942

By R. V. Norris

In a former paper on this subject,' I summarized Murgue's theory and experiments, and presented a large number of tests of mine-fans, stating some conclusions, " more or less warranted by the evidence," as to design, capacity and efficiency. Since that time the very valuable report of Mr. M. Walton Brown: Committee on Mechanical Ventikators, Institution of Mining Engineers, has appeared, and I have made additional experiments which tend to clear up some points in connection with this subject. Design and Tests of the Luke-Fidlbr Colliery Fan. The Luke-Fidler fan (see Figs. 1, 2 and 3), built to replace an old wooden fan at a very fiery colliery, presents some pecu-

Jan 1, 1905

By Charles E. Weaver

During the past few years there has been considerable activity in prospecting for oil and gas in several parts of western washington. From time to time seepages of oil or emanations of gas have been reported from various places. Several companies have been organized for the purpose of drilling, but only a part of these have actually begun operations. In certain localities very small seepages of oil occur, but up to the present time no oil or gas in commercial quantities has been obtained. In order to determine the conditions which may be favorable or unfavorable to the occurrence of petroleum it becomes necessary to know the character and extent of the geological formations in which such deposits might occur. In other regions where producing wells have been developed it is possible to know what formations contain the oil and what structural conditions influence its concentration in reservoirs or zones. It is usually possible to determine those strata which contained the materials from which the petroleum may have been derived and also the position and distribution of the more porous sandstone belts into which it may have collected. Detailed stratigraphic surveys may even determine the depth at which a certain known oil-bearing zone may be tapped at any particular place. It is also possible to recognize those formations which are presumably barren of oil, as well as those which are absolutely so. In new regions far distant from any of those which are now producing or have produced in the past, it becomes absolutely impossible to foretell whether oil may exist in commercial quantities or not. Assuming that such deposits do exist, it is extremely difficult to predict at what depth the produciqg zone or zones occur. However, in prospecting in a new and unexplored region, use should be made of such laws as have been found to govern the occurrence of petroleum deposits in other well-developed fields. Such deposits in their world-wide distribution are found almost exclusively associated with sedimentary rocks. Areas composed predominatingly of igneous and metamorphosed rocks are to be rcgarded as extremely unfavorable localities for the occurrence of commercial deposits of oil or gas. Assuming that such oil deposits are

Jan 1, 1916

By H. S. McQueen

The insoluble-residue method for the examination and correlation of limestones and dolomites, or other sedimentary rocks containing calcium and magnesium carbonates, originated and was developed in the laboratory of the Missouri Geological Survey. The numerous and ever-increasing problems in the field of applied geology, and the need for a tool or aid in the solution of them, led to experimental work with samples collected from deep wells, in the early part of 1924. The success attained, almost at the outset, with this method was so great that the method has now been developed from the state of the experimental to the realm of large-scale, every-day routine. In a previous paper the writer1 described the procedure in detail and the characteristics of the residues obtained from certain Paleozoic formations in Missouri. The purpose of the present paper is to discuss the economic application of the insoluble-residue method. Developmental History Within the Ozark region of southern Missouri the geologic column consists of Lower Ordovician (Canadian of Ulrich) and Upper Cambrian formations, which are composed mainly of dolomite with subordinate amounts of sandstone, shale and limestone. Chert is found to some extent in all except one of the dolomite formations. The stratigraphy of the region is complex because the dolomites have lithologic similarities, fossils are few and often poorly preserved, and identifiable horizons within the comparatively thick formations are not common. Although considerable stratigraphic work of an areal nature had been done for a period of many years by the Missouri Geological Survey, the detailed geologic succession had not, until a few years ago, been systematically worked out. The problems of subsurface stratigraphy were even more complex. This region constitutes the main ground-water province of the State of Missouri and within it wells of varying depths are drilled in order to obtain supplies of ground water. In the work of the State Geological Survey in connection with the drilling of water wells for public supplies * Published with the permission of the Director, Missouri Geological Survey and Water Resources. Manuscript received at the office of the Institute Feb. 20, 1936. Assistant State Geologist of Missouri; Missouri Geological Survey, Rolla, Mo. References are at the end of the paper.

Jan 1, 1937

At its meeting on February 21, 1933, the Board of Directors the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated:

Jan 1, 1944

At its meeting on February 21, 1933, the Board of Directors the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated:

Jan 1, 1941

By W. D. Forgeng, P. F. Wieser

MnSi alloys containing from 2 to 24 at. pct Si have been investigated by metallographic and X-ray methods. Contrary to published data, the temperature of the ß-manganese to a-manganese transformation is lowered by the addition of silicon. The existence of two additional intermediate phases E and ( is demonstrated. E, ranging in composition from 12 to 15.5 at. pct Si, forms by a peritectoid reaction between ß manganese and the second new phase, (. The latter phase is homogeneous at silicon contents from 16.2 to 18 at. pct and forms peritectically from the 0 phase and liquid. The eutectic reaction occurs between the ( phase and MnsSi rather than the ß phase and Mn3Si. As a result of this investigation, a modification of the manganese-rich section of the MnSi equilihrium diagram is proposed. The binary diagram of Mn-Si, according to Hansen,' Fig. 1, exhibits in the low-silicon region (below 24 at. pct Si) a peritectic transformation at 900°C of 0 manganese + Mn3Si to a manganese as determined by R. Vogel and H. Bedarff2 as well as a thermal effect at 980°C between 16.2 and 22.6 at. pct Si reported by the same authors. The nature of the latter transformation was unknown. K. Amark, B. Boren, and A. westgren3 reported indications that possibly four more phases existed in the range of 10 to 27 at. pct Si. The present investigation deals with the phase relations in the range of 2.1 to 17.7 at. pct Si. A few spot checks were conducted up to 23.84 at. pct Si. EXPERIMENTAL PROCEDURE Small experimental heats were prepared by induction melting in a vacuum furnace using argon as a protective atmosphere. The crucible was of commercial-quality magnesia. The furnace charge consisted of silicon metal and dehydrogenated electrolytic manganese. The typical analysis for these materials is shown in Table I. The molten alloy was tapped into 2-in.-square, 7-in.-long ingots. After visual inspection, a small quantity of alloy in the middle portion of the ingot was separated for use in this investigation.MnSi alloys containing from 2 to 24 at. pct Si have been investigated by metallographic and X-ray methods. Contrary to published data, the temperature of the ß-manganese to a-manganese transformation is lowered by the addition of silicon. The existence of two additional intermediate phases E and ( is demonstrated. E, ranging in composition from 12 to 15.5 at. pct Si, forms by a peritectoid reaction between ß manganese and the second new phase, (. The latter phase is homogeneous at silicon contents from 16.2 to 18 at. pct and forms peritectically from the 0 phase and liquid. The eutectic reaction occurs between the ( phase and MnsSi rather than the ß phase and Mn3Si. As a result of this investigation, a modification of the manganese-rich section of the MnSi equilihrium diagram is proposed. The binary diagram of Mn-Si, according to Hansen,' Fig. 1, exhibits in the low-silicon region (below 24 at. pct Si) a peritectic transformation at 900°C of 0 manganese + Mn3Si to a manganese as determined by R. Vogel and H. Bedarff2 as well as a thermal effect at 980°C between 16.2 and 22.6 at. pct Si reported by the same authors. The nature of the latter transformation was unknown. K. Amark, B. Boren, and A. westgren3 reported indications that possibly four more phases existed in the range of 10 to 27 at. pct Si. The present investigation deals with the phase relations in the range of 2.1 to 17.7 at. pct Si. A few spot checks were conducted up to 23.84 at. pct Si. EXPERIMENTAL PROCEDURE Small experimental heats were prepared by induction melting in a vacuum furnace using argon as a protective atmosphere. The crucible was of commercial-quality magnesia. The furnace charge consisted of silicon metal and dehydrogenated electrolytic manganese. The typical analysis for these materials is shown in Table I. The molten alloy was tapped into 2-in.-square, 7-in.-long ingots. After visual inspection, a small quantity of alloy in the middle portion of the ingot was separated for use in this investigation.

Jan 1, 1964

G. F. LOUGhlin,* Washington, D. C.—With reference to Mr. Bain's paper: The scarcity of adequate geologic data on building stone reflects, among other things, a lack of interest on the part of geologists. It has been one of my duties to attend to matters relating to building stone and other structural materials that have come to the U. S. Geological Survey, but for several years my principal administrative and other duties in the Section of Metalliferous Deposits have prevented me from giving structural materials the attention that they deserve. I have felt that investigations relating to structural materials should be assigned to someone else, but thus far nobody with a sufficient interest in the subject has come forward; further, the specific calls for these investigations have been so few and far between that it has not seemed practical to draft any one for the job. The general situation is such that steady and substantial progress in the application of geology to the utilization of structural materials is not likely to be made unless someone with keen interest in the subject takes the initiative. If the start is once made, I know from experience that cooperation from the more progressive members of the quarry and building industries will be readily forthcoming. Mr. Sales' suggestions are all constructive and most welcome. A thorough, detailed discussion of them might be as long as his manuscript, but could largely be summarized with the one word "amen" qualified by the alibi that a chronic shortage of funds and therefore of personnel has prevented us from carrying out some of his suggestions already. A few of them might call for an Act of Congress before we could undertake them, and one or two, such as the preservation of mine maps, with which I heartily agree, would call for much additional space as well as clerical and supervising help. Several items in Mr. Sales' paper—for example, the question of balance between the scientific and more directly practical studies and the surveys or resurveys of the larger and smaller mining districts—have been covered in my contribution to the symposium. The suggestion of frequent reviews of progress in the study of ore deposits is excellent and can be followed without serious diversion from projects already on the Survey's program. Brief reviews by Survey men have been published in periodicals, and the contributions by several of them to the Lindgren Volume1 may also be cited as serving this purpose to some degree. The practice of publishing short papers by Survey men in outside journals rather than in Government reports is largely the result of experience and expedience. Our printing funds are limited, and considerable time must elapse between the transmittal of a paper and its publication. Time is saved therefore by sending papers to outside journals, and the editors of those journals are usually glad to receive them. Members of the Survey would doubtless prefer to have the products and byproducts of their official work appear in official Survey publications if conditions were more favorable. If we were left entirely to ourselves the balance between the more scientific and the more directly practical studies would be somewhat better than it is, but the

Jan 1, 1935

G. F. LOUGhlin,* Washington, D. C.—With reference to Mr. Bain's paper: The scarcity of adequate geologic data on building stone reflects, among other things, a lack of interest on the part of geologists. It has been one of my duties to attend to matters relating to building stone and other structural materials that have come to the U. S. Geological Survey, but for several years my principal administrative and other duties in the Section of Metalliferous Deposits have prevented me from giving structural materials the attention that they deserve. I have felt that investigations relating to structural materials should be assigned to someone else, but thus far nobody with a sufficient interest in the subject has come forward; further, the specific calls for these investigations have been so few and far between that it has not seemed practical to draft any one for the job. The general situation is such that steady and substantial progress in the application of geology to the utilization of structural materials is not likely to be made unless someone with keen interest in the subject takes the initiative. If the start is once made, I know from experience that cooperation from the more progressive members of the quarry and building industries will be readily forthcoming. Mr. Sales' suggestions are all constructive and most welcome. A thorough, detailed discussion of them might be as long as his manuscript, but could largely be summarized with the one word "amen" qualified by the alibi that a chronic shortage of funds and therefore of personnel has prevented us from carrying out some of his suggestions already. A few of them might call for an Act of Congress before we could undertake them, and one or two, such as the preservation of mine maps, with which I heartily agree, would call for much additional space as well as clerical and supervising help. Several items in Mr. Sales' paper—for example, the question of balance between the scientific and more directly practical studies and the surveys or resurveys of the larger and smaller mining districts—have been covered in my contribution to the symposium. The suggestion of frequent reviews of progress in the study of ore deposits is excellent and can be followed without serious diversion from projects already on the Survey's program. Brief reviews by Survey men have been published in periodicals, and the contributions by several of them to the Lindgren Volume1 may also be cited as serving this purpose to some degree. The practice of publishing short papers by Survey men in outside journals rather than in Government reports is largely the result of experience and expedience. Our printing funds are limited, and considerable time must elapse between the transmittal of a paper and its publication. Time is saved therefore by sending papers to outside journals, and the editors of those journals are usually glad to receive them. Members of the Survey would doubtless prefer to have the products and byproducts of their official work appear in official Survey publications if conditions were more favorable. If we were left entirely to ourselves the balance between the more scientific and the more directly practical studies would be somewhat better than it is, but the

Jan 1, 1935

By David M. Hopstock

The performance of the most common type of low-intensity dry magnetic separator is analyzed on the basis of fundamental physical principles. Expressions are developed for estimating the optimal choice of design and operating parameters for beneficiation of magnetite ores. By proper choice of these parameters either a high-grade concentrate or a low-grade tailing can be produced from an incompletely liberated feed.

Jan 1, 1976

By E. A. Anderson

THIS seems to be the year for superlatives in A.I.M.E. meetings. The programs of the various Divisions and Institute committees offered an abundance of interesting and valuable information in the form of technical papers, symposia. and lectures to large and interested audiences. The Institute of Metals Division may hold up its head with pride for its own program. With six technical sessions, three full-day symposia, and the annual I.M.D. dinner, four meeting days were not enough and many simultaneous sessions were required. The quantity and quality of the paper were equaled by the numbers and interest of those attending.

Jan 1, 1944

By Charles F. Brush

THE compression of gases to a very high degree, for purposes of scientific research, has long presented serious difficulties to the physicist. Great advances have been made of late years in the construction of ordinary air or exhaust pumps, while very little has been done towards the improvement of compression pumps. The principal difficulties encountered in the construction of such apparatus are the existence of the so-called "dead space" in the pump barrels, leakage of the piston packings under high pressure, and the trouble arising from the unequal expansion of parts caused by the development of the latent heat of the gas during compression. Of these obstacles to success, the "dead space" is far the most serious, as it fixes a limit to the performance of the pump beyond which it is impossible to carry the compression. The writer having occasion, some time since, to make a series of investigations on gases very highly compressed, and finding no apparatus, or description of apparatus, adequate to produce the required

Jan 1, 1876

By Milnor Roberts

CORNWALL, a Mecca for metal miners the world over, is easily reached from the southern coast of England. Passengers who land at Plymouth or Southampton can connect with a fast train from London called the "Riviera express," which traverses the beautiful counties bordering the English Channel. In Cornwall the traveler soon notices the pits and stock-piles of white china clay, and the metal mines, both placer and hard rock. The deposits are associated with granite batholiths, of which there are four principal ones, each a few miles in diameter. Tin mines are especially worked in the granite near its borders and also in the immediately surrounding Paleozoic slates. Copper and lead are no longer of importance here but tin is being produced steadily from several mines, with arsenic and tungsten as by-products. At the close of the war the man-power available. for these mines had been reduced to one-third of normal, and only now is it again reaching full strength. As mining in Cornwall antedates the Christian era, even a Nevada prospector would have to admit that "she's a permanent camp." SUB-TROPICAL CORNWALL Redruth and Camborne are industrial centers of the tin mining industry, but more tourist hotels are found in neighboring resorts such as St. Ives, a quaint fish-ing town on the Atlantic-side of the peninsula of Corn-wall, where the numerous cats descended from those mentioned in the ancient riddle-rhyme about St. Ives now occupy every doorstep and wall. Another charm-ing resort. Penzance on the shore of the English Channel, is known by name to the public through the opera "The Pirates of Penzance," but is of especial in-terest to students of nature for its palm trees and other subtropical plants, which thrive owing to the nearness of the gulf stream, although the latitude is that of northern Newfoundland, Winnipeg, and the northern end of Vancouver Island. Among the industrial plants at Camborne are those of Holman Brothers, Ltd., where drills and other forms of mining equipment are manufactured. At the Corn-wall School of Mines, which specializes on the district, the staff has assembled excellent collections of local ores, which repay study by a visitor.

Jan 1, 1928

By Robert C. Mackenzie

EXAMINATION by the differential thermal analysis technique of a large number of samples of soil and other clays from various parts of the world has demonstrated that the occurrence of cold-precipitated hydrated ferric oxide (the identification of which in soil clays has previously been reported5) is not confined to any limited locality; e.g., it has been found in varying amounts in clays from Britain, France, South Africa, and Mexico. The conditions necessary for its formation have not yet been elucidated in spite of the number of samples examined, and, since this mineral is so easily prepared in the laboratory, it has been considered that a study of its constitu¬tion and of the conditions under which it could be prepared might. lead to a better understanding of the factors involved. These experiments form the subject of this short paper, and while they do not supply a definite answer to the mode of formation of this mineral in nature, they may, it is hoped, add something to our knowledge in this direction. EXPERIMENTAL WORK Materials Employed The a-Fe2O3.H2O (goethite) and B-Fe2O3.H2O (Weiser and Milligan") were obtained from the Department of Geology, University of Aberdeen, and Rothamsted Experimental Station, respectively. The beta material had been prepared by the method described by Fernelius.1 y-Fe2O3.H2O (lepidocrocite) was prepared at the Macaulay Institute for Soil Research by the method of van Schuylenborgh.6 The method employed for preparation of the cold-precipitated hydrated ferric oxide* was as follows: 1: 1 NH4OH was added (moderately fast with rapid stirring) to a solution of 5 grams FeC13.6H2O in 250 ml distilled water at room temperature (ca. 15°C) until red litmus turned blue, and then 2 to 3 drops in excess. The resultant precipitate was filtered off on a Buchner funnel and washed free from Cl- with distilled water. Previous experiments having shown that drying over P2O5 at room temperature or drying at 105°C in the oven did not significantly affect the thermogram,5 samples were nor-

Jan 1, 1952

By W. C. Leslie, R. M. Fisher, K. G. Carroll

J. S. Bowles and J. K. Mackenzie (Commonwealth Scientific and Industrial Research Organization, Mel- bourne, Australia)—The authors are to be congratulated for giving the first direct experimental proof that the observed macroscopic strain accompanying marten-site transformations is not necessarily a shear. We

Jan 1, 1953

By Ford R. Bryan, Edward F. Runge

BECAUSE of the need for ductile heat resistant alloys of non-strategic composition, there has been metallurgical development of Fe-A1 alloys possessing improved ductility and hot strength, together with high oxidation resistance. Iron and alu- minum form solid solutions up to approximately 35 pct Al. Alloys in the 8 to 12 pct A1 range are characterized by excellent oxidation resistance, high electrical resistivity' and, when appropriately alloyed, have creep rupture strength equivalent to that of the austenitic stainless steels.' At higher aluminum levels, the magnetic properties are of considerable interest. Nachman and Buehler" have recently reported on the desirable magnetic characteristics of the 16 pct alloy.

Jan 1, 1957

By Haley, D. F.

WHEN operations were first started at Climax in 1917 by the Climax Molybdenum Co., they were pioneering in the molybdenum industry for little was known relative to the uses of molybdenum or the metallurgy of molybdenite concentration. Concentration of molybdenite is relatively simple today but in 1916, when the Climax deposit first attracted attention, it presented serious difficulties. Little was known, in fact, even about the assaying of such low-grade molybdenum ores. Mine samples were sent to at least a dozen of the best laboratories in the United States and average values reported varied from 0.4 per cent to 1.0 per cent MOS2. Owing to the wide variations in MoS2 content obtained from reliable chemists, the actual value of the ore was most uncertain. This variation occurred repeat¬edly over a period of six months in 1917. It was finally decided, as a last resort, to cut several tons of sample from the tunnel and have a mill test made, using the recovered MoS2 per ton as the grade of the ore, for a small error in the assaying of the concentrate would not materially affect the results. These mill tests were made by the General Engineering Co. (Callow) at Salt Lake City. The results proved an ore of commercial grade and indicated the flotation process for the best metallurgy. Based upon these tests, the decision was made to build a 200-ton flotation plant. At this time, the art of flotation was

Jan 1, 1946