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By Courtenay de Kalb

The following observations upon onyx-marbles are fragmentary, and may shortly be rendered superfluous by the appearance of a work upon these interesting stones by Prof. George

Jan 1, 1896

By Steven Cordiviola, Richard Sergeant

The Kentucky Geological Survey(KGS) was established in 1854 as the official geologic research organization in the Commonwealth. Since that time the Survey has performed basic research in a number of geologic areas such as energy, applied geology, mineral resources, geologic mapping, and hydrogeology. Because of coal's importance to Kentucky, a significant part of the geologic data collected by the KGS is coal related. Coal-related data also occur in a variety of other KGS data sets such as the petroleum and water data files. To adequately respond to coal-related inquiries, the KGS maintains an inter- active, on-line data base in which various types of geologic and hydrologic information can be easily stored, retrieved, and manipulated. The KGS will continue to expand and update this data base through ongoing research, and by cooperating with the Kentucky Natural Resources and Environmental Protection Cabinet, Kentucky Department of Mines and Minerals, U. S. Geological Survey, and University of Kentucky Institute for Mining and Minerals Research. Data in this comprehensive system is available to State, Federal, and local governments; industry; researchers; and the general public. These data facilitate coal exploration, mine planning and permitting, coal production, and research activities in the Commonwealth of Kentucky.

Jan 1, 1983

Nature: Man is but one of the creatures which in- habit the earth, a dust speck in the universe. Thinking man has been concerned with his place and purpose in the universe since the earliest Egyptian and Chinese philosophers. Ancient creeds, as well as modern religions and philosophies of life, were concerned with the same problem. While such considerations and concepts have been valuable, theoretical philosophizing and dogmatic concepts are inadequate for a satisfactory solution of world problems of today. The concepts of man and life and their ultimate purpose should be sought in the relations of intelligent man to man and their relation- ship to the physical world. The quintessence of nature's accomplishment-man- is also the greatest disturber of nature and the greatest enemy of his own kind. While his spirit and mind defy and overcome natural limitations, his physical self is controlled by the same basic biochemical laws that govern any other form of living matter. This paradoxical duality of human voluntary and involuntary relations to nature is the source of the perpetual conflict between mind and matter. Therefore, the higher the spiritual evolution and perfection of the individual's mind, the greater and deeper the conflicting elements in their expression; and conversely, the simpler the mind or the mental and spiritual heritage, the less is the individual concerned with the conflicting elements.

Jan 1, 1950

ON JUNE 7 the German Government handed to the French and Belgians a new proposal for reparations, which offered 1,200,000,000 gold marks annually, to be guaranteed as to 500,000,000 by a mortgage on the national railways, as to another 500,000,000 by a mortgage on industry, commerce, land and factories, and as to 200,000,000 by a luxury tax. The number of years for which this payment should run to be left to settlement by an international conference. This offer was taken under consideration by the French and Belgians, who instituted conversa-tions with the British in the hope of arriving, at some joint action with respect to the Germans. Up to the end of June nothing had been determined. In the meanwhile, the continued French and Belgian occupation of the Ruhr seemed to develop a condition of guerilla warfare, considerable bloodshed occurring throughout the region. The second Lausanne Conference dragged on, the Allies being apparently unable to take any firm, joint stand, while the Turks increased their importunities and managed to get concession after concession. Early in June a revolution occurred in Bulgaria, the previous Government under Premier Stambulisky, based on the agrarian party, being forcibly thrown out by a bourgeois and military combination. This pro-duced considerable disorder in Bulgaria, outside of which country the nature and purpose of the revolution does not appear to be well understood. Stambulisky's partisans offered feeble, isolated resistance to the revolu-tion; in connection with which there was some blood-shed and Stambulisky himself was reported killed, although this was later contradicted. Professor Zan-kof, the new Premier, issued a statement, that the change of the Government was the result of discontent, that the foreign policy of the new Government would be peaceful, and that Bulgaria would continue to fulfill her international obligations, particularly the treaty of Neuilly. It was the opinion of London that the immu-nity from taxation enjoyed by the farmers under the agrarian regime is likely to he superseded by more equi-table taxation, and in general that the bourgeoisie will be better administrators of the public affairs In domestic affairs industrial activity continued at a high rate, but there was distinct relaxation in the demand for raw materials, and also in some manufac-tured goods. During June there were reductions of prices by many of the automobile tire manufacturers. There seemed to be also further contraction in the demand for automobiles.

Jan 6, 1923

By Harry E. LeGrand

Most mine operations are hampered to varying degrees by excessive inflow of water into mines or scarcity of water for processing the materials. These internal problems are compounded in many cases by such external hydrological problems as lowering of ground-water levels in areas outside the mine properties, subsidence of ground surface, adverse geochemical changes, and pollution. The development of a mine below the water table disturbs the natural ground-water system, causing a convergence in the flow of water from a surrounding area. The mine becomes the apex of a depressed cone in the water table. The fact that mines are commonly located in complex and somewhat anomalous geologic environments prevents an idealized treatment of the mine as a well that would be similar to a water well in a homogeneous aquifer having isotropic conditions. Yet, adherence to some principles of ground-water behavior is helpful when combined with an understanding of the local geology. A program calling for an appraisal of all pertinent hydrological conditions prior to mining and during various stages of development should supply adequate information for mine officials to anticipate difficulties and to allow for corrective measures. Before and during mining operations there should be a mine hydrology framework and plan, in which there is continual upgrading of such considerations as anticipated actions, consequences of actions, remedial plans, and contingencies.

Jan 1, 1973

By W. C. Kerr

When Agassiz and his party of geologists commenced their exploration of the interior of Brazil and the Amazon region, one of the first and, to the last, one of the most novel and striking phenomena which met them everywhere was the great depth of decomposed or partially decayed rock in situ, which mantles, and for the most part conceals, the underlying strata. The same facts strike all geological observers from the North who happen to penetrate the middle and southern latitudes of the Atlantic States. In North Carolina, e. g., the entire middle and western regions, outside of the Quaternary clays, sands, and gravels of the East,—that is, all that portion of the State occupied by the Archæan and Mesozoic rocks,—show everywhere this peculiarity, so new to those accustomed to glaciated surfaces. Not only do the hills and slopes, the mountain chains and

Jan 1, 1880

By E. C. Mahan

THE text of my talk was suggested by the invita-tion of your secretary, who said that the excess productive capacity of the bituminous industry was a matter of common concern to engineers and coal operators. Cognizant of the depressed condition of the industry, he tactfully added that in common council we might find wisdom. Certainly it would seem that the application of the best engineering knowledge available would be helpful in solving mining problems. There is no doubt that clear thinking, characteristic of the engineering type of mind, is essential to untangle the shapeless pattern which increased complication, so often mistaken for progress, has developed. There is much thinking today which neither looks forward to a logical combination of ideas nor backward to simple fundamentals. The result of that sort of thinking is hopeless confusion. Lately we have heard much about excess capacity and overproduction, along with their attendant evils. Respecting the bituminous coal industry, these terms have been frequently misused. How many of us have seen them applied to the coal industry but how few of us have understood them. I am reminded of a state-ment which William Green, president of the American Federation of Labor and a former miner from the Ohio field, gave to the Associated Press last month, in which he was quoted as saying: "The coal men must realize that conditions have altered since the World War. To-day they are producing a billion tons a year, with a market for only half that tonnage." I cite this instance as a glaring example of the flood of. loose statements about the bituminous industry with which the public is being deluged. If the general public, or some of the newspapers, had any passion for the facts, this sort of misleading statement would not get very far. Unfor-tunately, in these days, opinions are more sought after than facts, and statements by such a person as Mr. Green and are promptly accepted by a credulous public.

Jan 4, 1928

The Institute has prepared a list of Societies' publications, magazines, . etc., which were duplicates and were discarded at the time of the consolidation of the libraries of the three Founder Societies. These books will be disposed of about March 1, 1916 by the Board of Directors of the Institute through the Library Committee. If, meanwhile, members who have incomplete sets of these books, or for any other reason desire to secure some of them, they are asked to communicate immediately with the Secretary, as this is in unusual opportunity to secure books at a very low price. American Gas Light Journal, viols. 31 to 39. American Institute of Electrical Engineers, Transactions, vols. 5 to 26. American Machinist, vols. 3 to 20, 22 to 29. American Society of Civil Engineers, Transactions, vols. 2 to 10, 21 to 24, 26 to 33, 39 to 49, 52, 55, 58, 74. Index, viols. 1 to 21. American Society of Mechanical Engineers, Transactions, vols. 1 to 28. Index, vols. 1 to 20, vols. 1 to 25.

Jan 1, 1916

By J. Marin, H. A. B. Wiseman

This paper presents results of an experimental study dealing with the plastic stress-strain relations of aluminum alloy 14s-T6 subjected to combined biaxial tension and compression stresses. Plastic stress-strain relations for both constant and various types of variable stress ratios were determined and a comparison made with the simple flow theory of plasticity. THIS investigation was undertaken for two main purposes: 1—to obtain plastic stress-strain relations for Alcoa 14s-T6 when subjected to various combinations of biaxial stresses, and 2—to determine the validity of the flow theory in predicting plastic stress-strain relations for combined stresses. The biaxial stresses used were tension combined with compression. These stresses were produced by subjecting a thin-walled tube to axial tension and torsion. Various types of combined stress conditions were investigated. To provide control test data and information on the influence of biaxial stresses on the strength, the usual constant stress ratio type tests were made. These tests showed that the biaxial yield strength agrees approximately with the distortion energy theory. However, the Prager semi-empirical theory agrees best with the test results. For these constant stress ratio tests the plastic stress-strain relations were found to agree approximately with the flow theory. (For constant stress ratio the flow and deformation type theories are identical.) In view of the fact that the constant stress ratio tests cannot distinguish between the flow and deformation theories, a number of variable and special biaxial stress tests were made. These tests showed that the flow theory is inadequate, since large differences exist between the experimental and theoretical results. Special tests were also conducted to check the validity of the isotropic yielding assumption. This assumption is made in the linear-type flow theory. In these tests specimens were loaded in tension to predetermined values beyond the proportional limit stress. The tension load was removed from the specimen and the specimen was subsequently loaded in torsion to fracture. Other tests were applied with the order of torque and tension loading reversed. The nominal stress-strain curves for these two tests approximately coincide indicating that the assumption of isotropic yielding is valid. In addition, these tests verified the requirement by the slip theory of plasticity that prestraining below 140 pct of the proportioned limit stress in either torsion or tension did not influence the subsequent plastic stress-strain relations in tension or torsion. Another type of test was conducted to check the assumption that the axes of principal stress and strain coincide during plastic flow and variable stress conditions. These tests were conducted by applying combinations of axial tension, internal pressure, and torsional loads such that the axes of maximum principal stress could be rotated through 90" during the loading path. The results of those tests showed that the angle between the axes of principal stress and strain varied greatly and that the assumption of coincidence between axes of principal stress and strain is not valid. Introduction In various metal processes including forming of sheets, rolling of bars, and extrusion of rods, metals are subjected to stresses beyond the yield strength of the material. Often these stresses are not simple stresses acting in one direction, but are combined stresses acting in more than one direction. Structural and machine members are often subjected to combined stresses. To adequately determine the factors of safety for these members, it is necessary to know the plastic stress-strain relations of the material used for various combined stress conditions. Various theories have been proposed for predicting the plastic stress-strain relations for combined stress in terms of the simple tension plastic stress-strain relation for the material. To determine which theory might be adequate, test results must be obtained for various combined stress conditions, in order to compare the actual with the assumed theoretical behavior. Although there is considerable test data available for combined stress conditions in which the principal stress ratios are constant, relatively little test information is available for vari-

Jan 1, 1954

By Emmanuel Detournay, Charles Fairhurst

A method is proposed for computing (a possible solution of) the ground reaction curve, for use in tunnel support analysis, in cases where the initial stress field is not hydrostatic. Rock around a circular tunnel is assumed to behave as an elasto-plastic material with a Mohr-Coulomb yield envelope.

Jan 1, 1982

By Dwight L. Baker, Alexander Knoll

The work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those of high surface tension; i.e., nitrobenzene, diphenylmethane. Wetting Properties of Galena in Nonaqueous Fatty Acid Solutions When a "captive bubble"I is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method." When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1943

By Alexander Knoll, Dwight L. Baker

The work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those of high surface tension; i.e., nitrobenzene, diphenylmethane. Wetting Properties of Galena in Nonaqueous Fatty Acid Solutions When a "captive bubble"I is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method." When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1943

INTRODUCTION It has been impossible for the student, the practicing engineer, and the geologist to find all of the essential elements of mineral appraisal and mineral economic analysis in a single text. Indeed, the most recent texts on mine evaluation are over 20 years old. Many of the basic principles of mine sampling and evaluation have not changed over the ensuing years, but with the advent of the digital computer the entire scope of mineral evaluation has been expanded to encompass superior techniques that heretofore were not possible when using manual methods. The old manual methods for ore reserve computations and the techniques for assignment of area of influence to drill-hole samples are now as antiquated as the Model-T Ford. With the computer making possible solutions that had not been practicable in terms of time and effort, it is important for the practicing explorationist and mining engineer to understand many of the new concepts and principles that can be applied with the resolving power of the computer. Many practicing mineral industry professionals have been disappointed by certain computer programs and thus have some reservations about computers being able to solve their very real problems. Often the gap between the practicing engineer and the ivory tower theoretician applying modern computer techniques is too broad to be bridged with scattered, fragmented publications. PURPOSE AND SCOPE OF TEXT It is the intent of this book to update and to unify a great many scattered reference works used in the mineral industry today. The ensuing pages are addressed both to the professional already working in the mineral industry who needs information on computerized methods as well as to the serious student seeking to grasp the fundamentals and modern techniques of mineral appraisal and feasibility. These techniques are based on sound mathematical principles and theory, with the computer as a tool-but a very essential tool-for the solution of the problems involved. The computer can be of value only if it is programmed by those having sufficient expertise to use its inherent problem-solving capability, and the output is interpreted by those who are sufficiently acquainted with its operation to understand the data it produces. In the pages that follow the author intends to outline in considerable detail all the essen-

Jan 1, 1980

By John D. Clark

ONE'S lifetime does not usually offer the opportunity to observe and be a part of the commercial development of an entirely new material. Petalite has been known for over a century, but at first it was presumed rare. However, it was found to be so abundant that it has become a new and extremely useful industrial tool.

Jan 10, 1950

By W. B. Mather

Of the 61 dikes examined some yielded cassiterite, tantalite, and beryl; eight contained spodumene; and six carried amblygonite. Two mines stockpiled spodumene as a byproduct. Only zoned pegmatite dikes carried lithium minerals. GEOLOGICAL studies have revealed the occurrence of hundreds of pegmatite dikes in northeast Brazil, Fig. I, in the three states of Rio Grande do Norte, Paraiba, and Ceara. Heretofore data have not been available on the possible production of lithium minerals from these areas, and in March, April, and May 1953 the author undertook a reconnaissance survey covering a cross-section of the pegmatite~. Sixty-one pegmatites were examined. The pegmatites of Rio Grande do Norte and Paraiba are located in an arid region (Seratao), and except in the most southerly portion there is a minimum of vegetation and overburden. The region is easily prospected and relatively accessible by jeep or truck. The pegmatites examined in Ceara are in an area of lush vegetation along the flanks of the Jaqueribe River valley. It is therefore more difficult to prospect, and the dirt roads, as a means of access, leave much to be desired. For all practical purposes rail transportation, except in Ceara, is not available. The rocks of the area are composed of Pre-Cambrian schist, gneiss, quartzite, and marbles. They have been intruded by granites, monzonites, and diorites and cut by quartz veins and pegmatites. Pre-Cretaceous erosion reduced the area to a peneplain upon which Cretaceous or younger sandstones were deposited. Recent erosion has left only a few remnants of these younger rocks. In most of the Rio Grande do Norte-Paraiba area the pegmatites were more resistant to erosion than the enclosing schists and therefore stand out in relief. This is not true in the rolling country of Ceara, where the pegmatites lack topographic expression. With regard to structure and lithology, the pegmatite~ of northeast Brazil are divided into two types, uniform and zoned. Of the 61 examined, 19 belong to the uniform and 42 to the zoned type. Uniform pegmatites are normally long, narrow, and tabular, with sharp contacts. They are composed of an intimate mixture of feldspar (microcline or ortho-clase), mica (biotite, phlogopite, or muscovite), and quartz. The grain size5 varies from fine at the contact to coarser in the interior. They are not considered a commercial source of pegmatite minerals, although efforts have been made to produce green beryl of gem variety. This type of dike is often abundant in schists and gneisses close to granite intrusives. The productive dikes — lenticular, pod-shaped, or irregular in outline, with sharp contacts — are of the zoned variety. Zone contacts are gradational, except for those with the quartz core. Zones re identified as follows, see also Fig. 3. Border Zone: This outer zone, in contact with the country rock, is composed chiefly of fine-grained muscovite and biotite, with lesser quantities of finegrained microline and quartz. It is the narrowest zone, usually measurable in inches. Wall Zone: Lying between the border and intermediate zones, the wall zone is composed of medium-grained feldspar (often microcline), muscovite, and quartz. Usually it is the widest zone. Widths of 50 ft were noted. Intermediate Zone: Lying between the wall zone and core, the intermediate zone is composed principally of coarse-grained microcline (occasionally with some orthoclase and albite). It may also carry minor amounts of coarse-grained quartz and fine to medium-grained mica. The width varies from less than 3 ft to more than 30 ft. Core: The center of the dike is composed almost entirely of massive quartz, occasionally with minor amounts of fine-grained muscovite. The width reaches 30 ft. Lithium and other minerals of potential economic value are found in the following zones:

Jan 1, 1955

By T. Olrog

Dissemination of technical data on developments in rock-blasting techniques in Sweden initially takes place as personal contacts and contacts between companies. In addition to these informal contacts, contacts occur in Sweden in a somewhat more organized form. There exists an informal working group--the Rock Blasting Committee--which consists of a number of personal representatives from various companies that perform rock blasting on a large scale and from firms manufacturing the equipment that is used. This means that people from both mining and construction companies get together, plus the manufacturers of explosives, drill steel, drilling machines, and loading equipment. This working group has, so far, succeeded very well in ignoring the purely commercial interests of the companies concerned. Cooperation in this form was started in the 1940's when the tungsten-carbide drill steel was invented-the group originally concentrated entirely on the development of that product. Their activities have been broadened since that time and now a meeting is held every year, at which practical experiences are reported. Only in the past five years have subjects relating to blasting procedures to avoid rock damage been treated at such meetings. This, of course, does not mean that such techniques had been neglected previously. It does, however, reflect the fact that practice in this field is still under development. Why do we try to be careful about the rock surfaces? Obviously, it is a question of economic evaluation. An even rock surface provides, in certain cases, the conditions for more favorable maintainance costs later on, greater strength, and a diminished risk of slides. The economic connections in this field, however, are neither simple or clear. A well-controlled blasted rock surface limits the need for concrete when you later build the concrete constructions. In this respect, the connections are all the more clear. In certain situations, such as tunnels for hydroeletric power plants, a good rock surface that is not lined is hydraulically more favorable than a more coarsely blasted surface. This permits a gain in the height of fall, but the

Jan 1, 1970

By James C. Fisher

Traditional uranium exploration techniques were utilized and comparatively evaluated in the Front Range, Colorado uranium province. Intense surficial leaching and thick colluvial cover render traditional airborne and ground radioactivity reconnaissance prospecting useless. Radon gas emanometry and sulfur gas emanometry were slightly more effective but the long and short term variations In soil gas emanation rates make it extremely difficult to gain useful information from these systems. The technique judged most useful was Track Etch radon prospecting. The excellent definition of the technique, as well as its repeatability, indicate that it is an ideal prospecting tool for narrow vein-type deposits similar to those of the Front Range, Colorado.

Jan 1, 1976

By Harold B. Ewoldt, Robert R. Reynolds

THE Upper Mississippi Valley zinc-lead district covers an area of some 2000 sq ml located in the southwestern corner of Wisconsin, the north-western corner of Illinois and a portion of eastern Iowa around the city of Dubuque. Commercial deposits of lead and zinc have been mined in Iowa but the major discoveries during the past eight years have been made in Jo Daviess County, Ill, and LaFayette County, Wis. Activities in the state of Illinois are centered about the city of Galena, while those in Wisconsin are located a few miles south and west of the town of Shullsburg.

Jan 3, 1951

By W. P. Blake

Among the many interesting objects to be seen at the Vienna Exhibition last summer, the model of the system of underground transportation by a continually moving chain, adopted at the Hasard collieries, at Micheroux, near Liége, Belgium, was one of the most attractive, and full of valuable suggestion to mining engineers. These collieries are under the superintendence of the celebrated

By George A. Miller

OIL, the abundance of it in the hands of the Allies and the lack of it in the hands of the Axis, played a major role in winning World War II. It bids fair to implement the winning of the peace. In fact the signing of the revised agreement on petroleum between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the United States of America on Sept. 24, 1945, may be considered as the first step in establishing a new pattern in foreign relations by our Government. The significance of this agreement on petroleum is that it was arrived at on the part of the United States of America through the advice and consent of the most interested parties, the leaders of the petroleum industry and the Government, distinctly a first step toward unifying the power of business and the strength of the Government, which places us on a par with the British Crown which has always had the advice and counsel of its business leaders in formulating its foreign trade policies. And what is the thing so patently discernible in this new first step toward winning the peace? It is that the petroleum agreement, the first draft of which, signed in Washington on Aug. 8, 1944, almost caused an epidemic of apoplexy among the leaders of the oil industry, represents the desire of the people most concerned with the problems of petroleum both at home and abroad. This new agreement, which will come up before the Senate for ratification this month-hearings will commence in January - derives its "power from the consent of the governed," something about which our forefathers were vitally concerned once upon a time.

Jan 1, 1946