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By Walter Lawson

THE first plans were made in 1930 for the mining by open-pit methods of the low-grade disseminated ore body now known as the Morenci open pit. It was not until 1937, however, that final plans were completed and the decision reached to go ahead with the actual development. Many advances were made in open-pit mining equipment during that period of seven years, therefore the ways and means of attack actually used were very different from those originally contemplated. Diesel-operated bulldozers, big trucks, full-revolving electric shovels and electric churn drills constitute the major equipment finally purchased for this modern stripping operation. Neither the bulldozers nor the big trucks were considered in the early operating plans, for at that time bulldozers had not, been used in mining operations and the trucks as yet were undesigned. The full-revolving shovel and the churn drills were not new developments in open-pit equipment, but both had undergone remarkable manufacturing transition, emerging far more efficient and far more dependable than their predecessors. Even the ordinary drilling steel had been fundamentally changed. It was now threaded so that the dulled cutting bits could be detached and replaced, thus eliminating the costly transportation of long bars to the drill shop for resharpening. The decision to use trucks in the preliminary stripping operations was based on the desirability of this type of transportation to economi-cally prepare the pit for rail haulage, coupled with the success that the contractors had had with them on other big excavation jobs. There are at present no plans for the use of trucks beyond the preliminary work, inasmuch as rail haulage will give lower costs after roadbeds and benches are once established.

Jan 1, 1938

By Douglas Bunting

With the gradual exhaustion of the upper veins in the anthracite coal-fields, the problem of mining at greater depths acquires increasing importance and demands the consideration .of a number of important factors, one of which is the greater earth-pressure and the consequent necessity of stronger support for the roof. Under the pillar-and-chamber system, almost exclusively followed in the Northen anthracite-field, the highest economy in mining is generally secured by leaving, on first mining, pillars only sufficient to support safely the overlying strata. As to the necessary size of such pillars, the opinions of mining experts are widely divergent. In establishing the width of chambers and pillars, the thickness of vein and its depth below the surface have received little consideration. For instance, it has been quite usual to work both overlying and underlying veins with the same width of chambers and pillars, when the lower vein was two and one-half times as thick, and twice as far below the surface, as the upper. In view of the generally-accepted theory that the crushing-strength of coal-pillars of the same base-area becomes less with increased height, it is probable, in this instance at least, that the moat economical mining has not been secured. This question of adequate pillar-support is economically less important down to about 800 ft. than at greater depths; and it is with reference to mining at these greater depths that the study of the subject here presented has been prompted. The necessity of leaving larger pillars, involving greater mining-costs per ton and also smaller yields per acre, is one of the troubles of deep working. To mine without leaving adequate pillar-supports will result, sooner or later, in a squeeze. Limited areas, it is true, have been mined at certain widths of

Jan 1, 1912

By William E. Milligan

SELENIUM and tellurium occupy adjacent positions in the odd division of group VI of the periodic table immediately below sulfur, with atomic numbers 34 and 52 and with atomic weights of 78.96 and 127.61 .† A recent investigation has indicated the figures in Table 1 as the order of natural abundance of their isotopes. [ ] Experimentally, as a result of bombardment, many additional isotopes have been produced and studied. They are characterized by a relative short half-life. The elements of group VI in the periodic table are of great in-

Jan 1, 1953

Traditional finance theory recommends discounted cash flow (DCF) analysis as the tool to value mineral properties. Yet, the calculated values by this method are usually lower than the market value. Finance theory also advises us to develop an undeveloped project immediately if its net present value is positive. Most projects are, however, only developed when the economics are highly favorable. This paper uses insights from option-pricing theory to explain these divergences between market behavior and finance theory and presents simple modifications to discounted cash flow analyses that will lead them to produce correct valuation and development timing advice.

Jan 1, 1999

By A. L. Baxley

An Untapped Energy Resource As much as 20 billion cubic feet of natural gas per day are flared from remote oil fields for lack of a commercially viable means of capturing, transporting, and marketing such gas. The magnitude of these gas flares can be put into perspective from an early satellite photograph (Fig. 1) which shows lights from the major cities of Russia and Eastern Europe dwarfed by the natural gas being flared in the Persian Gulf. Together, these wasted resources contain the energy equivalent of about one-half of the gasoline consumption in the United States today (Fig. 2). Additional trillions of cubic feet of natural gas are "shut-in" because of no economically viable means of commercial recovery. Methanol and liquified natural gas (LNG) are the only two practical fuel products which can be produced economically from these gas supplies. Many of these gas supplies are less than 500 million cubic feet of gas per day, making an LNG facility uneconomic. In contrast, barge-mounted methanol plants can economically convert billions of cubic feet of gas per day into safe, clean-burning methanol. The methanol approach offers the only economical route to transform vast, known reserves of natural gas into a highly versatile primary liquid fuel. Methanol Barges: An Innovative Solution The barges will be towed to suitable offshore and upriver locations such as Alaska, South America, Africa, Southeast Asia, Australia, New Zealand, and the South Pacific Islands, as well as fields in the Persian Gulf and Mediterranean Sea. At the offshore production site, a barge will be anchored by a single point mooring buoy that will also serve as an entry point for natural gas feedstock and an offloading point for methanol (Fig. 3). At some sites the barge would be beached. Each barge will produce methanol and store it in internal tanks with a capacity of 18 million gallons. The methanol will be offloaded into conventional tankers and safely transported directly to market. Unlike LNG, methanol requires neither specially built carriers nor specially built receiving terminals. Once a particular gas field has been exhausted, the barge will be towed to another location to continue production. Each barge will measure 320 by 500 ft, approximately the size of four football fields, and will have the capacity to produce 1 million gallons or 2800 metric tons of methanol per day, from approximately 100 million cubic feet of natural gas per day (Fig. 4). The barges will use the highly successful "low- pressure" design developed by the Lurgi Company of Germany, a process proven in land-based methanol plants throughout the world during the last ten years. The decision to use Lurgi technology for "sea-trans- portable" methanol plants was based on the higher efficiency and greater operability of the technology compared to other commercially proven processes. The conversion plant will be designed to accept a wide variety of feed gas compositions, and will produce chemical-grade methanol for the broadest market base (Fig. 5). To minimize costs and construction time, the barge-mounted plants will be built in the high technology environment of a domestic or foreign shipyard. Selection of the construction site for each barge will be dictated by the location of the production site and by the relative construction costs. A number of shipyards have the capacity to build several barges per year. The detailed marine engineering to integrate the design of the processing plant with the floating platform can be performed by numerous major engineering companies around the world. Production Economics The barge-mounted plant concept not only assures large volumes of methanol, but it also keeps the overall production cost low by minimizing construction cost and providing access to low cost natural gas feedstock with no alternative or a negative value. Together, these advantages make the barge-mounted methanol plants economical today. The cost structure of a new barge-mounted methanol plant differs from that of existing methanol producers around the world (Fig. 6). For example, if a U.S. Gulf Coast producer is paying $4.70/MMBtu in 1985 for natural gas, the barge plant could afford to pay about $1.6O/MMBtu for gas and be able to deliver methanol to the Gulf Coast at the same price. At some future date such as 1990, a gas cost of $6.70/MMBtu for a domestic producer would have cost parity with about $3.60/MMBtu gas cost for the barge plant. In many foreign markets, feedstocks other than natural gas are used for methanol production (Fig. 7). For example, most of Japan's capacity is based on LNG while Western Europe uses residual oil or naptha. Because these feedstocks are substantially more ex- pensive than natural gas used by U.S. producers, the barge plants will compete even more favorably in these foreign markets. As crude oil prices rise, the value of methanol in each of these markets will increase. However, the hierarchy of methanol values in these markets should remain unchanged. Furthermore, the cost advantage for using methanol in these markets will improve as world energy costs increase since the value of remote gas should not escalate significantly.

Jan 1, 1982

By M. Gruber-Pretzler

Technical Sn- bronzes tend to form both macrosegregations and microsegrega¬tions during DC-casting due to the particular thermodynamic properties and kinetics of phase transformation. As a result a heterogeneous cast microstructure forms that is some¬times a reason for a decrease in workability. The extent of macrosegregations in DC-casting can effectively be influenced by casting parameters like casting velocity, primary cooling or inlet geometry which in fact change the relative flow between the melt and the forming solid. In order to understand the influence and interaction of the related phenom¬ena, simulation methods are applied. The solidification of the strand as well as the forma¬tion of macrosegregation are simulated with a two phase volume averaging model. The velocity field of the melt flow is explicitly calculated by solving the corresponding mo¬mentum conservation equations. Within the mushy zone the local formation of microseg¬regations in the presence of feeding flow is estimated. The thermodynamics of the Cu-Sn system is accounted for and it is distinguished explicitly between interface and average concentrations. To investigate the influence of feeding flow on the formation of mac-rosegregations, a study has been performed. Based on this result, the phenomena of mac¬rosegregations are described in a detailed discussion.

Jan 1, 2007

By E. Chin

Natural gas was Bangladesh's only significant exploited mineral. A few other minerals or mineral-based commodities were produced for local consumption. The most valuable were nitrogen fertilizer, salt, cement, and clay for brick.2 The most important mineral industry development of 1987 was the start of modest production of crude oil, the first discovered and produced in the country. PRODUCTION AND TIADE Production of natural gas from the nation's huge reserves continued to increase but was limited by the lack of residential and industrial demand. Gas reserves of 7 trillion to 16 trillion cubic feet were sufficient for far more production than the country could efficiently utilize for many years. The country's consumption-to-reserves ratio was one of the lowest of the developing nations. Mineral exports have been insignificant, comprising a small amount of nitrogen fertilizer. Nitrogenous fertilizer exports could become important when planned new capacity comes on-stream. Mineral imports were dominated by crude petroleum.

Jan 1, 1989

By I. Garba

The Bin Yauri deposit in the Zuru schist belt of northwestern Nigeria is a vein-type quartz-sulphide-carbonate gold mineralisation hosted by a brittle fault zone. The occurrence of the mineralisation in a contact zone of a Pan-African granitoid was believed to be sufficient evidence of deposition from magmatic fluids. However, studies may now indicate a metamorphic source for the mineralising fluids. A study of rare earth element geochemsitry was used to investigate the nature of the fluid-rock processes involved and identify the sources of the auriferous mineralising fluids.

Jan 12, 1992

A model of dense medium cyclones is developed based on balancing the terminal velocities of the discrete particles due to the centrifugal force against a random turbulent eddy velocity. An expression of the form P - or Q _ 1 100 e."A where P is the partition number., is a function of cyclone efficiency, particle size and density differential between the particle and medium, and is the slurry spilt, is developed and may be used for regressing plant partition data. The above model provides an understanding of peculiarities of the partition curve such as asymmetrical tails, elevation of the cutpoint and elevation of the d50 with increasingly fine feed. The effect of feed variables such as particle size, medium viscosity and changes in spigot or vortex finder diameter is shown. A means of convoluting the partition curve with various feed washabilities is discussed together with how the above may be used to evaluate plant performance for a variety of feeds.

Jan 1, 1987

By J. Lyndon Rosenblad

The strength of a jointed-rock mass is not well-understood. It is believed, however, that the behavior of a rock mass is governed by both the intact rock properties and the properties of the discontinuities. Rock research in the past has been concentrated on the determination of intact rock properties. Several studies are presently underway which should provide more insight into the properties of the discontinuities. Few research programs, however, have been undertaken with the intent of studying the composite rock mass behavior where either the intact rock strength or the properties of the discontinuities may control failure. There are three approaches available for studying the behavior of a rock mass, namely, field studies, mathematical models (finite element), and geomechanical models. A geomechanical model has been developed in this study where the strength and failure modes of a model rock mass are studied as a function of intact block geometry, joint orientation, joint properties, and confining pressure. The objective of this study is to gain some insight into the parameters that govern the behavior of a rock mass, which parameters are most important, and when these parameters control. This chapter describes only one phase of the study, the development of equipment for use with the rock-blocks model. The models being tested are approximately 22 x 22 x 6-in. The size varies slightly depending upon the joint orientation used. The equipment developed includes model material molds, reaction frames, loading apparatus, measuring and recording instrumentation, and other accessory equipment pertinent to the operation of a successful study. The usual problems in equipment development, such as uniformity of load application, loading capabilities, and reaction capacities are all

Jan 1, 1970

By Ketteridge IB, Mulcahy DE, Quast KB

The long term energy demands in South Australia are such that there is a distinct possibility that one of the lignite deposits in the State will be exploited to feed a pulver- ised-fuel power station. Bowmans lignite deposit is the largest lignite deposit in South Australia and is considered to be a contender. The deposit is ideally situated (100 km north of Adelaide) but the quality of the lignite is poor (see Table 1). TABLE 1

Jan 1, 1984

By Amanda C. Lima, Luiz Augusto H. Terrones, Sergio N. Monteiro

"Fabric from weaved yarns made of jute fibers have been considered as reinforcement for polymeric composites. In particular, these fabrics obtained from discarded sackcloth are presently being investigated as environmentally friendly composites with recycled polyethylene matrix. The objective of the present work was to compare the practical properties and economical aspects of these composites with those of conventional materials such as wooden board and gypsum panels for building application. The comparison showed that, depending on the amount of post-used jute fabric, a cost/benefit analysis favors these composites over the conventional materials.IntroductionThe increasing amount of wastes generated by human activities is becoming a worldwide problem of pollution with growing consequences to the environment. The question on how to dispose these wastes is, therefore, a major global issue. Among the possibilities of it gating the problem, the use of materials with characteristics of being renewable, biodegradable and recyclable is considered an environmentally correct solution. Examples of this type of materials are left over lignocellulosic fiber from coconut husks and sugarcane bagasse [1] that, after the primary extraction of edible pulp and juices, can be recover for industrial application. Nowadays, the main use of these fibers is to reinforce polymeric composites applied as components for building construction and automobile parts [2,3]. In addition to these applications, composites reinforced with residual lignocellulosic fibers may replace conventional furniture and panels made of wood and thus help to reduce deforestation [4].Environmental protection is not the only motivation for recycling natural fiber wastes. In developing regions activities associate with collecting and processing residual fibers provide job opportunities for low-income people. Moreover, if the lignocellulosic fiber is collected as a recyclable waste, it hes the economic advantage of a comparatively cost, which constitutes in a relevant difference as a choice for commercial utilization."

Jan 1, 2008

By A. Roper

Since the Toronto conference in May 2002, the International Council on Mining and Minerals (ICMM) has made progress on the road to sustainability. Fifteen of the world?s largest mining and metal producing companies and twenty-five associations have made a long term commitment to ICMM to improve the environmental and social sustainability of their activities. Sir Robert Wilson (Rio Tinto) assumed the chairmanship of ICMM in October 2002. By December 2002, the Council had approved a Strategic Vision and an operating plan for 2003. Both have been posted on the ICMM website (www.icmm.com). ICMM?s Operating Plan sets out three priority tasks: - Providing strategic leadership to achieve improved sustainable development performance in the mining, minerals and metals industry. - Contributing to international policy discussions on cross-cutting issues of importance to the industry, in collaboration with national and commodity associations. - Promoting dialogue and partnership with other organizations to catalyze sector?wide sustainability initiatives.

Jan 1, 2003

By A. A. Lavrinenko, N. I. Gluhova, L. M. Sarkisova, D. V. Makarov

"The investigated sulfide Cu-Ni ores are characterized by low PGE contents and emulgated impregnations of pentlandite and palladium minerals in the main ore-forming mineral pyrrhotite, which hinders their selective separation, requiring a collective flotation of sulfides to concentrate, and hydrometallurgical processing. As revealed by studies of floatability of Pt-Cu-Ni ore in a mixture of butyl xanthate and chelating phosphorus containing reagents, the most effective additive is Aerophine 3416 (a phosphinates mixture) manufactured by Cytec. Using collective flotation with a butyl xanthate – Aerophine 3416 composite in the ratio of 1:3 has afforded to enhance the Pt, Pd, and Ni recovery by 13.6 %, 9.2 %, and 9.4 %, respectively. The optimal ratios of Aerophine 3416 to butyl collector for the collective flotation are the following: 1:1 for Pt and Pd and 3:1 for Ni. The effect of these reagents on the electrode potential and surface hydrophobicity of pyrrhotite, pentlandite, and platinum black has been investigated. The extraction UV spectrophotometry experiments demonstrate that DIBDTPI exists on the pyrrhotite surface mainly in the form of disulfide in weak acid medium and in the form of compounds with Fe on the mineral surface in minute amounts. There appears some disulfide and few amount of (DIBDTPI)2Ni on the surface after interaction of DIBDTPI and pentlanditeINTRODUCTIONXanthates are widely used in flotation of copper-nickel ores containing platinum group metals (PGM) as sulfides collectors which can concentrate the most part of PGM connected with the sulfides. Though xanthates are hardly efficient for flotation of free PGM, the latter are floated more slowly compared to the sulfides of base metals. The reasons for poor floatation of free (mineral) forms of PGM are under-researched, however the key accepted reasons are: fine disseminations of free PGM, insufficient interaction with xanthate and negative influence of blue copperas and sulfur-containing ions which are sulfides oxidation products (Penberthy et al. 1999; Shackleton et al., 2007). That’s why an additional collector, normally dialkyldithiophosphates, is used during flotation of PGM-containing copper-nickel ores. A reagent DP-4 is used for recovery of PGM at Norilsk mining and metallurgical plant. The reagent represents a slightly-soluble organic calcium sulfonate which is given to flotation pulp in the form of water emulsion of 5% - solution in automotive diesel oil."

Jan 1, 2016

By W. Setzepfandt, J. Henneke

PREFACE Debris disposal can very often be a severe problem and major restriction on tunnel boring projects, especially for small diameter tunnels and in underground mines. Hydraulic transport could provide a suitable solution. Investigations have therefore been made in connection with a full-scale project of 4.8 km length and 2,3 m diameter, to obtain the required technical and economical data for planning an optimized transport system, e.g. for a tunnel boring drivage of 6 - 7 m diameter in underground coal mines. INTRODUCTION The Radau-Tunnel, chosen for the investigations, has been designed for transferring flood peaks between the rivers Radau and Grosse Romke in the Harz-Mountain of Lower Saxony. A DEMAG TVM 20/23 H tunnel boring machine was used to drive the tunnel on a rising gradient of 0,53 %. The rock consisted of shale and hornblende (55 %), granite (15 %), diabase (15 %), chert (8 %) and gabbro (7 %). The project has been sponsored by the Federal Ministry of Research and Technology.

Jan 1, 1981

By C. T. Bischoff

This paper describes the results of testing with colorimetric methods, using "dithizone", soil samples taken over various known copper and zinc deposits covered by glacial till. Variation in results is shown for different depths and types of overburden as well as grade and type of deposit. Limiting factors for the practical application of this work are discussed. The method has proved successful for copper and zinc deposits under clay and fine sand with depths up to at least 30 ft but fails in coarse sand and gravel unless depths are very shallow. Swamps require penetration to the underlying subsoil for sample material. DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one. This paper deals with investigations along these lines with particular emphasis on soil sampling. The problems involved from the start were: 1—Which types of glacial soil, if any, would best lend themselves to testing, and conversely which types might be considered relatively hopeless? 2—Through what depths of overburden could significant mineralization be detected? 3—What sampling techniques would prove economically applicable? This included minimum depth of sample and maximum spacing that could be allowed.

Jan 1, 1955

By Arch J. Alexander

This paper is a resume of a study undertaken by the West Virginia Department of Mines. The underlying and direct causes of accidents are determined in each occupational group. Then from this study, accident prevention courses, visual and written, are to be taken to the various working groups in the mines. THE causes of accidents in West Virginia mines follow the main pattern of coal industry accidents in the United States—falls of roof, ribs and face, 56 pct; from haulage, 25 to 30 pet; blasting, 3 pet; electrocutions, 3 pct; explosions, 2 pct; and other causes, about 10 pct. To arrive at some satisfactory conclusions regarding causes and prevention of mine accidents, the Department of Mines has made a study of all mine accidents, from 1945 to 1948, inclusive. During the last two years of this period, we did not have a major explosion, one that took the lives of as many as five men. The direct cause of these accidents is apparent in the reports but we who are making a close study into their frequency think that the virus lies much deeper, and we want to suggest an underlying cause. The rapid growth of the coal industry in West Virginia, the largest producer of bituminous coal, has resulted in a demand for manpower which probably has never been equaled in mining history. At the turn of the century, West Virginia had 24,635 men employed in and about her mines, and they produced 21,153,341 tons of coal a year. In 1948, there were 125,669 men employed, and coal production for the year was 168,589,033 tons, an average increase of 35 pct for each year since 1900. Over 100,000,000 tons of this increase were mined in the southern counties of the state. A safety analyst might read into the history of this development an underlying cause for accident occurrence. He might say that in such a vast, rapid development the available supply of trained miners became exhausted and that young, inexperienced men were employed in the mines by the thousands. Being unacquainted with the hazards of mining, it would be only natural for these young men to be injured or killed in too great a number. This assumption would not be borne out by the records. Men were not injured or killed in disproportionate numbers during their first years in a mine. The only reason we can give is that, during these years, they possessed an attribute of safety—CAUTION—to a much greater degree than in the years following. The coal companies in West Virginia that have been operating over a number of years have a nucleus of employees who have been with them ten, twenty, thirty, and forty years; many of them having gained all of their mining experience with one company. Their habits of work have been

Jan 1, 1951

By Arch J. Alexander

This paper is a resume of a study undertaken by the West Virginia Department of Mines. The underlying and direct causes of accidents are determined in each occupational group. Then from this study, accident prevention courses, visual and written, are to be taken to the various working groups in the mines. THE causes of accidents in West Virginia mines follow the main pattern of coal industry accidents in the United States—falls of roof, ribs and face, 56 pct; from haulage, 25 to 30 pet; blasting, 3 pet; electrocutions, 3 pct; explosions, 2 pct; and other causes, about 10 pct. To arrive at some satisfactory conclusions regarding causes and prevention of mine accidents, the Department of Mines has made a study of all mine accidents, from 1945 to 1948, inclusive. During the last two years of this period, we did not have a major explosion, one that took the lives of as many as five men. The direct cause of these accidents is apparent in the reports but we who are making a close study into their frequency think that the virus lies much deeper, and we want to suggest an underlying cause. The rapid growth of the coal industry in West Virginia, the largest producer of bituminous coal, has resulted in a demand for manpower which probably has never been equaled in mining history. At the turn of the century, West Virginia had 24,635 men employed in and about her mines, and they produced 21,153,341 tons of coal a year. In 1948, there were 125,669 men employed, and coal production for the year was 168,589,033 tons, an average increase of 35 pct for each year since 1900. Over 100,000,000 tons of this increase were mined in the southern counties of the state. A safety analyst might read into the history of this development an underlying cause for accident occurrence. He might say that in such a vast, rapid development the available supply of trained miners became exhausted and that young, inexperienced men were employed in the mines by the thousands. Being unacquainted with the hazards of mining, it would be only natural for these young men to be injured or killed in too great a number. This assumption would not be borne out by the records. Men were not injured or killed in disproportionate numbers during their first years in a mine. The only reason we can give is that, during these years, they possessed an attribute of safety—CAUTION—to a much greater degree than in the years following. The coal companies in West Virginia that have been operating over a number of years have a nucleus of employees who have been with them ten, twenty, thirty, and forty years; many of them having gained all of their mining experience with one company. Their habits of work have been

Jan 1, 1951

By Earl H. Miller, Henry H. Bruhn

COMMERCIAL beds of sylvite ore were discovered by the Snowden & McSweeney Co. while drilling a wildcat oil well some 25 miles northeast of Carlsbad, N. NI., in 1925. After a preliminary core drilling program the U. S. Potash Co. sank a 1060-ft shaft within 4 miles of the original discovery. This shaft was in an isolated location in a sand desert area with only the roughest of dirt roads connecting it with the neigh- boring town of Carlsbad some 21 ½ miles west.

Jan 6, 1954

By Thomas J. Peters

The U.S. Bureau of Mines studied the 63,9SS-acre Hanson Lakes study area, including the Ten Mile-East and part of the Ten-Mile West RARE II areas, plus additional acreage, all proposed at times for Wilderness designation. The study was part of a Idaho Land Assessment Program with the Idaho Geological Survey and the U.S. Geological Survey, to provide minerals information for land-use decisions, and ensure domestic mineral supplies. The area is at the north end of the rugged Sawtooth Range and includes parts of the Sawtooth National Recreation Area which is closed to mineral location. The Copper Mountain. Elk Mountain, and Observation Peak mineralized areas are in the study area, but only Copper Mountain is open to claim location. It is on the trans-Challis fault zone and contains Tertiary granite which is favorable for mineral deposits of gold, beryllium, niobium, REE (rare-earth elements), tin, molybdenum, copper, silver, and lead. Identified resources are 1.9 million tons of flake graphite at Elk Mountain, but much more graphite occurs in the vicinity REE occurs in 18 black sand placer sites along the lower reaches of study area streams just outside the study area, on Cape Horn Creek, Marsh Creek, and lower Valley Creek flood plains, and at one hydrothermal site near Observation Peak. Hydrothermal REE is commonly low in? by-product thorium. a radioactive disposal problem. Many advanced REE applications enhance the quality of life, and future uses in superconductivity may reduce energy consumption. Seventeen lode, one geothermal, and 11 placer prospects were examined. Workings totaled about 20 adits, one shaft, several open cuts, and numerous small pits. Approximately 500 mining claims have been located or relocated in the study area, including a 200-claim block for disseminated molybdenum.

Jan 1, 1992