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By Andrew J. Regis

The methods of evaluation of industrial minerals occurring on Federal lands have different meanings if the evaluations are done by a company rather than a government agency. For example, when the Bureau of Land Management (BLM) conducts an examination of mining claims, this is commonly referred to as a "validity examination," whereas it is an "economic evaluation" when performed by a company. Not only is there a difference in nomenclature in these evaluations, but there is a general lack of expertise in the Federal government on industrial minerals in general. A metallic mentality still prevails in the U.S. Forest Service (USFS) and the BLM. Because of this, many validity exams on industrial-mineral deposits commonly just skim the surface concerning economics and marketability. The BLM and USFS place a high amount of emphasis on past administrative case law pertaining to the validity of industrial minerals under the 1872 Mining Law and, rightly so, on marketability, which also is heavily addressed in case law. When the BLM considers marketability, only the marketability of a particular industrial mineral for only the primary use for which it was located is considered and any value-added markets cannot be included. The BLM defines marketability based only on the value of the mineral material in its in situ or raw state, rather than value-added through processing. Another difference in the evaluation of industrial minerals by government and industry is the question of by-products. When a company evaluates a mineral material it looks at all the markets. The BLM looks only at that market for that locatable mineral for which the claim was located. In other words, sales from non-locatable by-products cannot be used to support marketability or the prudent-man rule (i.e., oversize silica sand from a glass-sand claim being sold for construction sand, road base, fill, etc.). The question of reserves also can present conflicts. An industrial-mineral company will often try to identify all the reserves available for a possible future development. They must do this for financial backing and support from upper management. The BLM, however, will limit their validity examination only to those reserves that meet the prudent-man rule and marketability tests. The BLM will validate reserves sufficient to last 25-30 years, based on available market. The development of industrial minerals on Federal lands is a difficult process, and, if the 1872 Mining Law is changed, it could become not only more challenging but also more costly. The industry must become more tolerant of the mineral specialists in the BLM and the USFS. On the other hand, the government mineral examiners must become more aware of the importance of industrial minerals in everyday living, and the economic evaluation of these materials.

Jan 1, 1999

By R. Allan Wallis

In the past mining engineers have tended to rely heavily on the advice of fan manufacturers in relation to fan equipment issues. A more adequate approach was advocated in a paper [ Wallis, 1965 ] submitted to the Eighth Commonwealth Mining and Metallurgical Congress held at Surfers Paradise, Australia during 1965. At that time Mount Isa Mine were in the process of installing 3 large 6096mm (20ft) diameter vertical axial flow surface fans of an advanced type [ Mathews et al, 1967 ]. The preliminary feasibility studies prior to preparing the detailed job specification for this project were extremely thorough with the result that it was possible to include detailed information and instructions in the document, ensuring the procurement of equipment that was satisfactory in all respects. Full advantage was taken of expert services provided by external organizations during the large coordinated multi-disciplinary exercise. My continuing activity and development in relation to the technology of axial flow fans is now at a stage where all known design and performance data are accessible through CAD programs [ Wallis and Kipp, 1987 ]. The extensive calculations that were necessary in 1983 can now be carried out in a mere fraction of the time, and with complete confidence. Model testing in order to validate the fan and duct design proposals is, in my view, no longer essential. The first of the computer programs enables a mine ventilation engineer to study a large number of alternative axial fan arrangements for comparison with the centrifugal alternative. By entering the volume flow rate, fan pressure and air density, he can then with ease, and rapidly, investigate the effect of various blading arrangements, downstream evasee area ratios, and hub ratios, on fan diameter and speed, with their related attainable fan efficiencies. This procedure had its origin back in the 60s when I was advising mining companies on new fan equipment. At that time such an investigation was quite lengthy and lacked the precision and completeness that is now available within the present programs. To obtain the major benefit from these outputs, it is most important not to be disconcerted by the three very important nondimensional parameters, namely, the tip flow coefficient (LAMt), the fan pressure coefficient (Kt or Kit), and the swirl coefficient (Es and/or Ep) as these are important when assessing the various design proposals. When seeking an understanding of the role and importance of each of these variables, ample help is provided in the user manual; the design recommendations are summarized in the help screens which are readily accessible within the design programs.

Jan 1, 1989

By M. Henneman, M. Kosma, M. Eyll-Vetter

"For a long time, the recultivation of depleted opencast mines and operating systems was aimed at restoring the original state. The focus, as desired by policy-makers and the local population alike, was on restoring high-quality agricultural land and on creating reforested areas of value that suit their location. Until the turn of the millennium, recultivation measures were only rarely the subject matter of public planning processes beyond these general objectives. They were never regarded as nucleus and origin of sustainable structural developments. The rehabilitation of inactive lignite opencast mines in central and eastern Germany brought about a change in mind-set that understood recultivation to be a unique opportunity to completely redesign a landscape and gear it towards the future in the Rhenish mining area as well. The ""Inden residual lake"" and ""terra nova"" projects, planned in the last 10 years in cooperation with policy-makers and authorities, are two undertakings that provide sustainable structural impetus for the future today."

Jan 1, 2011

By F. Palmay, R. D. Gwilym, P. Eng

INTRODUCTION As the experience in Canada indicates, it is becoming more and more common to evaluate major mining projects, especially those relating to uranium, with respect to their environmental effects. As part of this evaluation public hearings are becoming the rule rather than the exception. In this area the 1970's and presumably the 1980's can be characterized as the age of "Environmental Assessments" or "Environmental Impact Statements" which form the basis of these hearings. These documents tend to require significant amounts of research, data collection and effort in their preparation, and tend to be closely scrutinized by the hearing body and by groups in opposition to the project. This opposition is becoming more organized and sophisticated. The assessment or impact document, together with the evidence supporting it during the hearings can: (a) mean the difference between a lengthy and hence costly hearing and a smoother, shorter and less expensive one, (b) result in requirements for extensive modification at the expense of the proponent to his project, (c) result in the proponent being required to carry out extensive studies, research or monitoring programs, and (d) conceivably may in certain situations result in the project actually being turned down. Therefore, while on the one hand it is important to have available technical answers to concerns relating to uranium, its associated and perceived hazards, it is getting more and more important to be able to present these answers in both a written and oral format in such a way as to meet the criticism and concerns of the opposition, be they citizens in general or special interest groups including environmental lobbyists. JURISDICTION From a Canadian perspective, the first legal question to be answered is which level of government has jurisdiction over uranium mines in general and specifically over aspects relating to the environmental effects, including the health and safety aspects, of uranium mines and

Jan 1, 1980

The impact of smoothing on the definition of ore and waste boundaries using linear estimation and conditional simulation methods is discussed. The nature of transfer functions is examined including their ability to incorporate categorical data (e.g. a dominant lithology code). An Ore Block Optimization (OBO) transfer function is presented that provides a clear guide for the mining geologist. Advantages are seen in defining stockpile cut-off grades and meeting production targets such as maximizing head grade, maximizing ore tonnes or minimizing ore loss or dilution. Each of these scenarios impacts on mine profitability and grade control.

Jan 1, 1999

By Harry J. Fitzgerald

During World War II mining machinery manufacturers were limited in the development of their product improvement programs. Following the war, however, the ideas and intentions of both the users and manufacturers of mining equipment became evident. The Coal Industry launched a series of events which indicated their determination to rise to the economic challenge of developing profitable machines which would eliminate the out-dated and back-breaking methods of mining previously used. Two major technological advances were developed as a result of the ambitious goals forecast by the Coal Industry: 1. Coal mining was going "off-track" and concentrated mining operations were to follow in rapid succession. 2. Carbide tools provided the remaining missing contribution to another technological breakthrough....Continuous Mining. Little did the inventors realize the significance of the misnomer they created because twenty-five years later the industry is still striving to secure the results implied by the meaning of the word...."Continuous". Nevertheless, all major manufacturers embarked on programs in an attempt to compete for recognition in this new mechanized-mining endeavor Eventually in 1950 there were three types of boring machines and two types of ripping machines being manufactured. Mining Speed was the desired goal.

Jan 1, 1970

When solid pillar is not left to separate different mining levels in underground mine with high dip angle deposit, waste rock in the backfilled stope could be a safety hazard to future mining activities on levels above or below the backfill. Different backfill methods can be used to eliminate this hazard according to the deposit shape and mining method. Building concrete pillar in ore drift of each mining level is one of them. Concrete pillar had been constructed in underground mines based on operational experience. Little design literature and pillar performance data can be found. At Great Basin Gold Hollister Mine, over two thousand feet of concrete pillar had been constructed. The project started with engineering design which combined civil engineering concrete design and the specialties of underground construction. Time Domain Reflectometry technique was installed to monitor the pillar movement and concrete cylinder samples were collected and tested for quality control. Engineering design, underground construction, quality control and concrete pillar monitoring, as well as precious concrete mixing data from years of experience are fully covered in this paper to give a general frame of concrete pillar method.

Jan 1, 2010

By M. D. Carter

The availability of environmentally acceptable and reliable energy sources is an important issue for Federal, State, and local planners. A cooperative program by the U.S. Geological Survey, State geological surveys, and the U.S. Bureau of Mines has developed a national GIS-based systematic effort to collect, analyze, and depict data characterizing the relationship between restrictions to mining and the potential development of the Nation's coal resources. Land use/environmental and technologic/geologic restrictions are identified within selected 1:24,000-scale, 130-to 150-sq-km 7.5-min quadrangles and applied as overlays to maps of coal-bed thickness, depth, and mined-out areas. Tonnages of original, mined and lost-in-mining, remaining, restricted, and available resources are calculated. Resultant data files are transferred to the Bureau of Mines for recoverability and cost analysis.

Jan 1, 1995

By Michael L. Cramer, Kunsoo Kim

INTRODUCTION The Columbia River Basalt beneath the Hanford Site is one of several rock types being considered by the U.S. Department of Energy for the first commercial high-level nuclear waste repository. The Basalt Waste Isolation Project (BWIP) has been carrying out a comprehensive investigation to assess the feasibility of constructing a repository in basalt and to develop technology required for repository engineering and site characterization. Development of a nuclear waste repository requires a number of design considerations not usually necessary in the planning of conventional underground structures. Principal among these is the thermally induced stress field resulting from waste emplacement. This thermal stress, super- imposed on the preexisting in situ- and excavation- induced stress fields, needs to be evaluated in the design process due to the sensitivity of waste emplacement density to this factor. The nature of this thermally induced stress field is dependent on several factors, including the temperature distribution around the repository openings, the thermal properties of the rock mass, and the deformability of the rock mass. Re1iable performance of the repository structure is largely determined by the ability to under- stand the above rock mass characteristics and predict the underground opening response to waste emplacement based on this understanding. To gain an understanding of this rock mass behavior in a repository condition, the BWIP has conducted a large-scale heated block test in basalt at the Near-Surf ace Test Facility (NSTF) on the Hanford Site. This paper presents the results from the elevated temperature phase of the block test in which the thermal, mechanical, and thermo- mechanical response of the closely jointed basalt rock mass was evaluated as a function of stress and loading orientation at varying temperatures up to 200 oC. SITE GEOLOGY The NSTF test areas, including the block test site, are located in the entablature zone of the Pomona basalt f low. The Pomona flow entablature is structurally typical of most flows in the Columbia River Basalt Group in that it is characterized by long, undulating, polygonal columns up to 2.4 m in length. Columns vary from 15 to 30 cm in diameter, averaging about 20 cm. Over their length, columns can vary in dip by 150 to 200. The column structures are dissected by subhorizontal cross joints that are generally discontinuous and seldom cross columnar joint boundaries. Spacing of the cross joints also averages about 20 cm. A representative joint pattern taken from mapping of the tunnel wall near the block test site is shown in figure 1. Application of the Rock Mass Rating System (Bieniawski, l979) to the block test site yielded an overall value of 62. The corresponding value from application of the Q-system (Barton et al., 1974) is 8.7 (Cramer and Kim,1985). The NSTF is approximately 50 m below the surf ace. However, this depth is sti1l above the water table and conditions are generally dry. Interstitial water exists as the result of percolation of meteoric water from the surface.

Jan 1, 1986

By Leonid Pevzner, Valerie Dmitriev, Yuri Babitchev

Performance of belt conveyors, service life of belts and mechanical elements can be radically improved if the automatic adjustment of the belt speed movement is made in such a way, that the unit load over the conveyor length be constant and close to the rated one under random input freight traffic. Such an adjustment is possible when the system of a controllable thyristor electric drive on the basis of induction squirrel cage motor is used. Computer-aided adjustment of the belt conveyor movement is effected via bicontour digital control of the main drive in order to redistribute loads when the loading of conveyor and contour of the control of tension drive are changed. The system envisages control and condition monitoring of the conveyor electromechanical system, as well as metering of electrical power and the amount of conveyor freight. The results of the simulation of speed control of the conveyor belt are given in the report. Mathematical model of the conveyor electromechanical system describes the movement of the belt with cargo and the tension drive. The input cargo traffic is assumed as stationary ergidic random process with the assigned characteristics. The solution of the problem of the synthesis of a closed-loop control system, the structure and parameters of adjustment, the conditions of asymptotic stability of the control back-up system and the condition of minimization of mean square error of shadowing are also given in the report. Microprocessor controller is used to realize the function of the adjustment unit. Under this control system standard mode of conveyor operation, different modes of start-up, operating mode with decreased speed when transporting people, service and emergency braking of a conveyor and some other modes are realized. The digital model of a conveyor as an instrument for decision making in case of emergency is used in those modes. MASTER TEXT Long-standing practice of belt conveyor operation in mines of Russia has proved their inefficient use with 40-70% capacity and 20-25% availability factor. It is associated with unreasonable power intensity and reduction of service life of mechanical components, and as a result, with the growth of total transportation costs. Low efficiency of conveyor application can be explained by the extremely irregular distribution of conveyor freight traffic. Usually, the width of a conveyor belt is identified in accordance with the possible maximum traffic value, engine power capacity for long-term operation under rated loads. However, actually a conveyor often runs without any load and its average load in most cases is lower than the rated one. The problem can be eliminated by way of the adjustment of the operational mode of a conveyor according to an actual input freight traffic via belt speed control providing for the conveyor regular linear load which is nearly equivalent to the rated one. Experimental research into freight traffic under working conditions of the operating underground and open-cast mines proves the fact that the actual freight traffic can be adequately presented through the model of stationary random function of time, for ex- ample, as a J (t) continuous random Gaussian process that is modulated with a G(t) elementary pulse flow:

Jan 1, 1996

By Bruce L. Bryson

In the past decade a principal growth area in refractory technology has been the development and use of extra high alumina refractories. The refractories user is asking for, and is prepared to pay for, higher purity, more dense materials with longer life, less maintenance, and better dimensional tolerance to meet the exacting demand of high output processes. High alumina and bauxite refractories are being used more and more to keep pace with the demand for guaranteed performance. The steel industry, for example, is starting to place great reliance on these products. A unique material now available with all the requirements for extreme purity and density is tabular alumina, already proving itself in many refractory applications.

Jan 1, 1973

By T. M. Yegulalp

One of the important factors affecting the determination of the minimum number of increments in a gross sample of coal is the variance component due to segregation. The segregation variance may be estimated by following the ASTM standard procedures. Since the estimate itself is a random variable, it is important to test if the value obtained is due to chance causes. This paper introduces a statistical test, based on the procedures published by ASTM, to test if the segregation variance is significantly greater than zero.

Jan 1, 1986

By Robert C. Sutter

In 1958, it became obvious to some of us in the solution mining business that there were certain problems in connection with our sodium chloride brining operations which were industry- wide. These were the types of problems which, while they were important to the safe and economical operation of our salt brining operations, were not such that their solutions would give an individual company a great competitive advantage over his competitor; and since they involve the safe and efficient mining of a natural resource, it was obvious that the answers would, in any event, be shared industry-wide. Since we were dealing with underground solution mining and, consequently, unseen and remotely controlled operations, the problems are formidable and the solutions difficult. While all of us were doing work to improve our operations, none of us could justify the expenditures necessary for basic research in these areas. Consequently, the idea was conceived of research sponsored by many companies with the same problems. In 1960, 11 companies entered into a' formal agreement to jointly support research on a specific problem of sodium chloride solution mining. The project to be undertaken was the development of a method for measuring the size and extent of underground solution cavities in sedimentary salt beds. It was agreed that all research was to be performed by independent research organizations. A part-time consultant or administrator was retained to administer the research contracts and to provide technical advice.

Jan 1, 1966

By D. V. Bush

The economic application of real time computer control can be broken down into 2 broad areas of concern. The first would be in gaining the most efficient utilization of energy. The second would be in improved product quality. This paper will be primarly concerned with the first area of efficient energy utilization as that area has the greatest effect on costs and thus net profits. Most process control strategy attempt to achieve the greatest comminution with the least amount of energy thus maximizing efficiency. A more direct approach to energy control involves a total mine and mill energy management system. In most cases these systems have an ability to achieve a very short payback period with the greatest return on investment.

Jan 1, 1986

By Sheldon P. Wimpfen

Under the Wilderness Act of 1964 and the accompanying House Conference Report, the Geological Survey and Bureau of Mines are charged with the responsibility of making recurring mineral studies of wilderness and wilderness candidate areas in national forests within and proposed for the National Wilderness Preservation System. The Wilderness Act, a major shift from the multiple-use concept of national forests, identified for the first time the value of mineral resource information in decisions for single-use designation of public lands. This concept was further realized when the Secretary of the Interior in May 1974 recommended that mineral studies be made prior to wilderness recommendations for five large Interior-managed game ranges and the Glacier Bay National Monument aggregating 7.8 million acres. Presently, our studies have been completed on 126 wilderness and proposed wilderness areas totaling 15.4 million acres in the national forests. In 1973, 1 year in advance of the act's 10-year review deadline, we completed the 34 primitive areas, originally the only potential additions considered by the 1964 Act.

Jan 1, 1975

By B. Pesic, J. E. Wey

Introduction One important class of manganiferrous ores is manganiferrous-silver ores. They occur in the oxidized portions of the silver deposits of the western United States. Silver is often associated with manganese oxides, which in some ore deposits are dispersed through calcite, causing the black color of the host rock, known as black calcite. Black calcites can occur in carbonate rocks (0.3 to 50 kg Ag/t) and in volcanic rocks (less than 30 g Ag/t). Silver mineralization associated with manganese oxides and black calcites can occur in veins (Hewett, 1968) or as disseminations (Graybeal, 1981). In the US, silver-bearing manganese veins are located in a broad arc that extends from southern Colorado to southwest New Mexico, southern Arizona, and southeast Califor¬nia (Hewett, 1964). Areas of disseminated silver-manganese mineralization include the Creede and Silver Cliff districts of Colorado and the Tombstone and Hardshell districts of Arizona (Graybeal, 1981). These deposits are also characterized by significant amounts of silver halides - cerargyrite (AgCl), bromargyrite (AgBr), and iodargyrite (AgI). Black calcites are also common in these deposits. Oxidized silver ores containing the higher oxides of manganese are generally refractory to hydrometallurgical methods of treatment. In the past when these ores could not be smelted, they were treated generally by cyanidation at very low efficiency. The US Bureau of Mines (USBM) studied the problem of treating silver-manganese ores in the early 1920s (Clevenger and Caron, 1925). It was found that the refractory silver in the original ore was insoluble in all the common solvents for metallic silver and its salts. The conclusion was that to obtain the highest recovery of silver, all the manganese had to be dissolved or the higher oxides of manganese reduced to manganous oxide. More recent results from treating refractory silver¬manganese ores were given by USBM (Scheiner et al., 1973). The silver ores from Candeleria District, NV, and Round Mountain District, CO, were investigated. Electrooxidation experiments recovered only 34% silver with minor amounts of manganese dissolved. Sulfurous acid pretreatment followed by cyanidation revealed that silver extracted was proportional to the amount of SO2 used. A similar approach, using sulfurous acid pretreatment followed by cyanidation, was also proposed by Rhoades et al. (1984). Hazen Research Inc. performed extensive testing on silver and manganese dissolutions from Ag-Mn ores obtained from the Candeleria and Round Mountain ore deposits. The methods examined were direct cyanidation, pretreatment with sulfurous acid followed by cyanidation, malonitrile leach, and leaching with ammonium hydroxide-sodium thiosulfate under slight oxygen pressure. The results were not satisfactory. The importance of the vast reserves of Ag-Mn ores and the lack of an efficient method to recover these metals warranted a search for new technologies. One novel method for extraction of these metals is treatment of Ag-Mn ores with acidified thiourea solutions. Preliminary results of the leaching of silver and manganese from Ag-Mn ores were very encouraging (Pesic, 1984a) ; thus, it was decided to examine the new lixiviant in more detail. Experimental Ore from the Round Mountain District was studied. It was crushed, ground, and dry sieved into monosized fractions in the range of 16 to +400 mesh. The ore composition was about 90 g Ag/t and 3% Mn, depending slightly on size. The leaching experiments were performed in apparatus described elsewhere (Pesic, 1982 and 1984b). All experiments were performed at constant temperature conditions. The leaching residues were analyzed for silver and manganese. Atomic adsorption was used to analyze the solution samples and fire assaying to analyze the leaching residues (for silver). The standard experimental conditions are given in

Jan 1, 1987

The Sandvik Group (Sandvik AB), headquartered in Sandviken, Sweden, continues to expand its worldwide operations growth. After recent acquisitions, including Tamrock, headquartered in Tampere, Finland, the company now has annual sales of more than US$5 billion (SEK 40 billion). With the acquisition of Tamrock, Sandvik has further increased its interests in the mining industry. Sandvik Rock Tools, a familiar name in the mining industry, is one of the world's leading suppliers of rock-drilling tools. And Tamrock is one of the world's leading suppliers of drilling machinery, loaders and equipment for rock-excavation operations. Sandvik believes that the two companies combined offer customers "maximum productivity through total system solutions, including machinery, service and tools." In 1997, Tamrock posted sales of US$940 million (SEK 7.5 billion). In addition to its expertise in drilling tools and equipment, Sandvik is supported by its collective resources in specialty steel and cemented carbide. These resources include extensive research and development capabilities, with annual investments in R&D now at about US$150 million. As a result of the R&D programs, internal expansion and acquisitions, the company has nearly doubled in size during the past four years. From 1994 to 1997, nearly US$1 billion was invested in internal growth and another US$825 million has gone towards acquisitions. Return on net assets is now 22% annually. In addition to Tamrock, acquisitions of interest to the mining community include Drillmaster Inc., Houston, TX. The acquisition of Drillmaster (by Sandvik Rock Tools) has further strengthened Sandvik's position in down-the-hole drilling tools. Other major recent acquisitions by Sandvik include Kanthal, a Swedish manu¬facturer of metal and ceramic-resistant materials for electric heating furnaces, household appliances and elec¬tronics, and Precision Twist Drill, Crystal Lake, IL, one of the leading producers of high-speed cutting tools. With more than 38,000 employees worldwide, the Sandvik Group is divided into six separate business areas. Each area is responsible for its own R&D, production and sales: ? Sandvik Mining and Construction. Including Tamrock and Sandvik Rock Tools, this business area boasts of offering the most comprehensive range of "rock-working" products. These include drilling rigs, loaders, rock-excavation equipment and rock drilling tools. ? Sandvik Specialty Steel. This area includes Sandvik Steel and Kanthal, manufacturers of stainless steel tube, strip wire and bar, as well as high-alloy steel and specialty metals. ? Sandvik Tooling. This business area consists of tools and tooling for metalworking applications. Sandvik Coromant is a market leader in the development, manufacture and marketing of tools using cemented carbide, ceramics and extremely hard materials, such as diamond and cubic nitrite. CTT Tools is the world's largest manufacturer of high-speed steel tools and is now expanding operations into solid cemented-carbide tools. ? Sandvik Hard Materials. This segment produces a full range of "hard materials," ranging from cemented carbide to diamond. This area manufactures and markets a full range of cemented carbide blanks for tool manufacturers, as well as components and rolls. ? Sandvik Saws and Tools. This business area manufactures high-quality handsaws and metal saw blades, as well as hand tools ranging from wrenches to chains for logging machines. ? Sandvik Process Systems. This segment manufactures steel belts, process systems and automatic sorting systems for the chemical

Jan 1, 1998

By Robert Y. Lamarche

INTRODUCTION Production of chrysotile asbestos from the northern Appalachians has been going on for 100 years and, on the basis of known reserves and the present rates of mining, appears assured of continued production for at least another 25 to 30 years. In spite of this, mining companies and government agencies are showing an increasing interest in exploring for chrysotile asbestos throughout this region and elsewhere in the world, implying that increases in the rate of consumption are envisioned. This chapter describes the geologic and tectonic settings surrounding these important chrysotile deposits, with emphasis on those in southern Quebec that yield about 90% of the total production from the northern Appala- chians. Detailed descriptions of a few individual deposits are also given, along with exploration guidelines aimed at facilitating the discovery of additional chrysotile deposits. One section of this chapter deals with the origin and mode of formation of the chrysotile deposits in the light of modern day concepts of plate tectonics. The objectives of this chapter are to give a brief description of the geologic and tectonic settings of the ultramafic rocks in which the numerous chrysotile deposits of the northern Appalachians are found; to describe a few of the individual deposits; to give a few exploration guidelines for those interested in exploring for new asbestos deposits in similar geologic environments; and to propose a new model for asbestos genesis in light of the recently developed theories of global tectonics. As this chapter is based almost entirely on field and laboratory observations, rather than on the study of experimental laboratory models, most of our deductions and suggestions are empirical in nature and may be interpreted in more than one way. The interpretations we have selected seem to offer, we feel, the best explanation of observed geological phenomena (Lamarche and Wicks, 1975). This region had a production capability in 1979 of close to p.5 Mt of chrysotile asbestos with 92% of this tonnage being derived from the deposits of the Eastern Townships of Quebec. With known resources, which now stand at between 36 and 40 Mt of fibers, this production capability seems assured for the next few decades. In spite of all known reserves of chrysotile asbestos, which now stand at between 36 and 40 Mt of fiber in this region alone, mining companies and government agencies are still showing a good deal of interest in exploring for new sources throughout the world. GEOLOGICAL SETTING The asbestos deposits at Baie Verte in eastern Newfoundland, Thetford Mines, Black Lake, Asbestos in southern Quebec, and Belvidere Mountain in Vermont, all occur in partly serpentinized ultramafic rocks that are part of the Lower Paleozoic ophiolite complexes of the northern Appalachians [Cady, Albee, Chidester, 1963, Chidester, Albee, Cady, 1978, Lamarche, 1972,1973, Laurent, 1973,1975, Williams, Hibbard, Bursnall, 1977, Norman and Strong, 1975). The deposits to the northeast of Thetford Mines, on the other hand, are found in a more highly serpentinized ultramafic body known as the Pennington dike, whose spatial, genetic, and chronological links with the ophiolite masses proper have not as yet been adequately resolved. The Appalachian ophiolites are part of an ultramafic belt (or belts), that extends from northwestern Newfoundland, through Quebec and Vermont. Fig. 1, and southwestward as far as the

Jan 1, 1986

By R. W. Ballmer

Bingham Canyon lies in the heart of the Oquirrh Mountains, 25 miles southwest of Salt Lake City, Utah. In it is located the world's largest open-pit copper mine, owned and operated by the Utah Copper Division of Kennecott Copper Corporation. From the beginning of open pit mining operations in 1906 until 1963, the pit haulage, or materials transportation, was primarily by rail. In 1963, phase-in of a truck haulage system in the upper two-thirds of the pit was begun. The details of that conversion, its associated problems and the resulting pit operation have been covered in an earlier paper.1 The purpose of this paper is to discuss various factors for consideration in transportation system selection, and to discuss some of the alternatives considered prior to making the change from rail haulage to truck haulage for a portion of Bingham Canyon.

Jan 1, 1968

By Sheldon P. Wimpfen

Forecasting, an ancient art, is con-ducted by everyone in varying degrees. It is a vital aspect of mineral production and conditions must be predicted over a long time frame in all aspects of the industry from exploration to plant construction. Although many government agencies as well as private industry make forecasts, there are insufficent "make good" analyses performed. The performance of more such studies could sharpen forecasting ability.

Jan 1, 1983