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By Phillip N. Yasnowsky

"In this Bureau of Mines report, the Federal income tax treatment of mineral exploration and development expenditures is summarized, and changes in the tax treatment of these expenditures since 1951 are detailed and analyzed. Although no attempt is made to establish causal relationships, major tax changes favorable to exploration and development activities did occur in 1951 and 1966 when the Nation was engaged in military actions and the economy was expanding. More recent changes have been unfavorable to exploration and development and were parts of major tax reform efforts. INTRODUCTIONThis Bureau of Mines report discusses the Federal tax law provisions relating to mineral exploration and development expenditures. These provisions, contained mainly in sections 616 and 617 of the Internal Revenue Code of 1954 (Title 26 of the U.S. Code), apply specifically to minerals (other than oil and gas), and thus are of interest to the Bureau of Mines.Bureau of Mines involvement in this subject stems from the legislative mandate in the 1913 amendments to the Organic Act of 1910 (the Act creating the Bureau) to conduct economic investigations of the mineral industries. Congressional concern with the financial conditions in the economic and mineral industries was expressed more recently in the Mining and Minerals Policy Act of 1970 and in the National Materials and Minerals Policy, Research, and Development Act of 1980. The General Accounting Office recommended in 1976 that the Department of the Interior ""identify and evaluate laws and agency programs that affect maintaining and developing a sound and stable domestic mining and minerals industry"" (17, p. iii). 2Taxes, a source of revenue to governments, are a cost to private firms. Thus, taxes directly affect private sector profits, and unique tax provisions are designed to encourage (or discourage) activities such as agriculture, construction, or mining. Even the international competitiveness of the domestic mineral industries may be affected by taxes because many minerals are traded in world markets."

Jan 1, 1985

By E R. Ramanaidou, M A. Wells

Reflectance spectroscopy is now an established technique for mineral exploration and ore characterisation. The efficacy of the technique as a tool to characterise the main iron ore and gangue mineralogy at African Minerals Ltd’s Simbili iron ore deposit in north-central Sierra Leone was tested through reflectance spectroscopic analysis of 13 000 pulped drill reserve samples using CSIRO’s HyLogger-1™ system. Specifically, integration of reflectance spectral data with more traditional methods of analysis, such as geochemical analysis and Satmagan measurements, characterised the mineralogy (ie hematite versus goethite) of the oxidised ore at Simbili, quantified the Al associated with goethite and hematite and evaluated the distribution of the main gangue minerals – kaolinite and gibbsite. Relative changes in the Fe2+/Fe3+-bearing oxide and silicate mineralogy, based on mineral indices derived from reflectance spectroscopic measurements, appeared well-related to changes in the ore profile mineralogy consistent with the main ore types identified at Simbili, as representative of an oxidised banded iron formation sequence. Spectral calibration models, developed from a well-characterised training set of mineral mixtures, representative of the oxidised ore zone mineralogy were used to quantify the distribution of Al associated with kaolinite and gibbsite and the iron oxides, goethite and hematite. Combining these mineral spectral parameters with compositional data enabled the differentiation of Al-substituted goethite and hematite and resulted in the identification of low Al-bearing, or ‘clean’, goethite and hematite from high Al-bearing, or ‘dirty’, goethite and hematite. Spectral quantification of the iron oxide Al composition provides a far more rapid means of quantifying the Al substitution in iron oxides at the deposit scale compared to traditional techniques such as X-ray diffraction analysis. It also enables a level of volumetric characterisation and the potential for large-scale (ie three-dimensional) mapping, which was not previously possible with other techniques. The potential of the technique was also highlighted when mapping the distribution of the main Al-bearing contaminants (gibbsite and kaolinite) identified in the oxidised ore zone at Simbili. Delineation of such zones provides a guide to managing the most appropriate processing options (ie upgrade potential) within a mineralogical framework. Three-dimensional modelling of the gangue phase distribution may also allow the mapping of lithological and/or structural controls that may be prevalent at Simbili. This work highlights the value in the application of HyLogging™ technology for rapid resource characterisation, particularly for volumetric identification and mapping the distribution of both the economic and gangue phases, which otherwise would be difficult to achieve. As such, the technique can provide a fast and inexpensive means to evaluate ore and gangue mineralogy at the deposit scale and provide a first-pass assessment of the mineralogy and compositional attributes, with the potential to better predict ore metallurgical properties.CITATION:Wells, M A and Ramanaidou, E R, 2015. Waste not, want not – delving deeper into the Simbili iron ore deposit using HyLogging™ scanning technology, in Proceedings Iron Ore 2015, pp 337–346 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By P S. Jaitawat, M Sarim, M P. Roy, P K. Singh, A Joshi

Mining is being carried out using the sublevel open stoping method at the Kayad underground mine. The mine will ultimately reach a depth of 390 m. Kayad village is only 100 m (horizontally) from the underground mining areas. As a result, blast-induced ground vibration is one of the major issues for the residents of the village. This paper deals with the process involved in optimising blast design parameters at the development face blast, slot raise blast and ring hole blast to control blast-induced vibration within safe limits while ensuring improved production, productivity and safety. In total, 1041 development face blasts, 110 slot raise blasts and 52 ring hole blasts were conducted, and 2612 vibration data were monitored in the village at different locations. Initially, electronic delay detonators were used, with an emphasis on controlling vibration in the surface structures. Subsequently, shock tube (Nonel) initiations were used as the blasting faces reached lower depths. A comparative study was also performed for both the initiation systems. The orebody width generally varied from 3.1 to 7 m, and ring hole designs were optimised accordingly. The number of holes in a ring was up to seven and the depth was up to 23 m, depending on the size/width of the orebody. The ring blasts were performed with 64–340 kg of emulsion cartridge explosive and detonated with explosive weight per delay of 10.92–17.16 kg. Extensive experiments were performed and blast-induced vibrations were controlled in the village. Deck blasting (ie up to four explosives decks) was used in a blasthole and the explosive charges were separated by delay detonators, which helped to control the vibration in the village. The actual detonation time of each deck was recorded by monitoring the in-hole velocity of detonation of the explosives, and the charging patterns were optimised accordingly to get the desired blast results.CITATION:Roy, M P, Singh, P K, Sarim, M, Jaitawat, P S and Joshi, A, 2015. Blast design and vibration control at Kayad lead-zinc underground mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 533–544 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By I. H. Warren, Forward F. A

The reduction of aqueous slurries of uranyl carbonate at elevated temperature with compressed hydrogen m the presence of metal catalysts and certain organic promoters has been shown. to yield uranium dioxide. The reduction takes place in a sequence of steps. The purity and sintering properties of the dioxide make it of interest as a starting material for fuel element production. Simple control can be exercised over the surface area and oxygen/uranium ratio of the product during reduction. URANIUM dioxide for fueling atomic power reactors 1s conventionally produced as a powder by simultaneously decomposing and reducing ammonium diuranate with hydrogen in a furnace at high temperature. Fuel elements are then generally made from this powder by compacting and sintering ( 1). In order that elements approaching theoretical density may be obtained,

Jan 1, 1961

By Arthur L. de Carle

"IntroductionThe Key Lake uranium-nickel deposits are located within a Mineral Lease centred at latitude 57 ° 12' north and longitude 105 °39' west along the southeastern rim of the Athabasca sedimentary basin in northern Saskatchewan, approximately 240 km north of La Ronge (Fig. 1). Access is provided by an allweather provincial highway from Pinchousc, situated about 200 km to the south, and a private airstrip maintained at the mincsitc.These deposits have been developed by Key Lake Mining Corporation on behalf of the Saskatchewan Uranium Joint Venture. Participants in the joint venture include Saskatchewan Mining Development Corporation (50%), Urancrz Exploration and Mining Limited (33 1/3 %) and Eldor Resources Limited (16 2/3 %).Considerable geological work has been conducted on the Key Lake orebodies and reported in summary papers published by Dahlkamp and Thn, (1977), Dahlkamp, (1978), Gatzweiler eta/., (1979) and Kirchner el a/. , (1980). However, intensive geological research is ongoing, particularly since many problems regarding ore genesis and controls remain unresolved . Exploration History and DevelopmentThe events (Gatzweiler eta/., 1980) which led to the discovery of the Key Lake ore bodies began in the summer of 1971 by following up on the reports of airborne radiometric anomalies and anomalous radon values in the Zimmer Lake water situated approximately 5 km to 6 km to the southwest. This work succeeded in locating a few high-grade uranium and nickel-bearing boulders associated with esker material. An integrated program, consisting of various geochemical and geophysical surveys along with diamond drilling, culminated in the discovery of the Gaertner orebody during July 1975. Subsequent fence drilling across the strike extensions of this ore structure located the Deilmann deposit, approximately I km to the northeast, in June 1976"

Jan 1, 1986

By J Youngson

Gold placers can be difficult to locate in areas where tectonic activity and paleogeography have changed significantly since placer formation. Existing placer exploration models are useful in areas that have a relatively simple geological history, identifiable relationships with parent sources, or a history of placer mining. However, exploration becomes increasingly difficult in areas where tectonic activity and sedimentary recycling repeatedly redistribute the gold. Gold placers in the Waitaki River catchment, North Otago, New Zealand have no primary source within the catchment. During the Eocene placer gold was transported by a river ('Buster River') that flowed in a northeast direction from Central Otago toward a coastline at Maerewhenua, North Otago. This river and coastal system was inundated by marine transgression during the middle Tertiary. Since the Miocene its placer deposits have been uplifted and eroded and any links with parent sources have been severed. Changes in paleogeography resulted in local reconcentration and local dilution of placer gold in different areas in the Waitaki catchment. Thin veneers of old Waitaki River gravels (Kurow Gravels), containing gold recycled from the older placers, have been deposited unconformably on strath surfaces cut into Tertiary or older rocks. These gravels along with remnant Eocene fluvial and shallow marine strata provide potential placer exploration targets. Uplift and erosion of non-auriferous rocks in the Waitaki catchment to the west and north of the study area has resulted in considerable dilution of potential placer deposits downstream, especially in areas of gravel aggradation. We present a placer exploration model that is founded on answering fundamental questions pertaining to the paleogeography and geological history of the sediments associated with the placers.

Jan 1, 1999

By L. T. Matthews, C. E. Loo, R. P. Williams

The behaviour of iron ores and fluxes in the high temperature zone of a sintering bed is extremely complex. Following a review of current knowledge, an attempt is made to define relevant terminology to describe the processes that occur in this part of the bed. A deformation temperature is used to quantify the initial formation of melt, which is produced predominantly by reactions between fine particles in the sinter mix. The subsequent assimilation of larger particles is considered to depend on the reactivity of the melt and the assimilation resistance of these particles. Novel laboratory experimental techniques are used to quantify these parameters. Results demonstrate that the properties of the raw materials used have an extremely important influence on the initial processes of melt formation and assimilation and also on the nature of the sintering reactions and sinter-bonding phases.

Jan 4, 1992

By M. K. Boateng, K. Awuah-Offei

"Mining companies have started using quantitative tools, including computer models of community interaction, to gain intelligence on social risks surrounding their projects. Models of changes in community preferences regarding mining projects over time are useful for evaluating changes in project risk due to changes in the social license to operate. For example, agent-based models that use information diffusion models and social networks are useful for studying those changes due to information diffusion. However, such agent-based models are sensitive to many input parameters including the parameters of the diffusion model and the average degree of the social network. This work evaluates the sensitivity of such a model to diffusion and network model parameters (probability of imitation, probability of innovation, and average degree) using the first order and total sensitivity indices. The results show that the model is much more sensitive to the probability of imitation than the other two parameters. Thus, to reduce uncertainty surrounding the model’s predictions of community acceptance of mining, mines need to obtain accurate estimates of the probability of imitation. INTRODUCTION Mining companies have started using quantitative tools, including computer models of community interaction, to gain intelligence on social risks surrounding their projects. Models of changes in community preferences regarding mining projects over time are useful for evaluating changes in project risk due to changes in the social license to operate. For example, agent-based models that use information diffusion models and social networks are useful for studying those changes due to information diffusion. However, such agent-based models are sensitive to many input parameters including the parameters of the diffusion model and the average degree of the social network. This work evaluates the sensitivity of such a model to diffusion and network model parameters (probability of imitation, probability of innovation, and average degree) using the first order and total sensitivity indices. AGENT-BASED MODEL OF COMMUNITY ACCEPTANCE A few researchers have started using agent-based models to study mining systems (Fujiono 2011; Nakagawa et al. 2013; Bahr 2015; Boateng and Awuah-Offei 2017a, b). Nakagawa and co-workers used ABM to evaluate dynamics of a mining project’s stakeholder networks whereas Fujiono used ABM to study innovation diffusion in the mining industry. Our previous work has presented models and a framework for modeling information diffusion in a mining community and its impact on level of acceptance (a measure of SLO) of the mining project (Boateng and Awuah-Offei 2017a, b)."

Jan 1, 2018

By Leykam Chris J., Jacobs Scott. A.

"Construction of the New NY Bridge over the Hudson River 25 miles north of New York City is one of the largest civil infrastructure projects presently underway in the United States (formerly Tappan Zee Hudson River Crossing). The $3.14 billion Design-Build contract is also the largest ever awarded by the state of New York using an Alternative Project Delivery method, and the first major public project to use Design-Build. The new 3.1 mile long bridge will replace the existing Governor Malcolm Wilson Tappan Zee Bridge with a modern twin crossing featuring: Iconic side by side cable stay main spans; significant deck widths accommodating eight lanes of regular traffic, wide shoulders, and a shared use pedestrian and bike path; foundation with excess capacity to fully support a future rail bridge; more than 1,000 large diameter pipe piles driven in deep glacial deposits; drilled shafts installed through steep blast-rock slopes on the east shore landings. Geotechnical challenges included varied bedrock and glacial till surfaces with steep slopes and depths in excess of 750 ft.The purpose of this paper is to highlight major features of the New NY Bridge project with specific focus on the design and construction of the foundations supporting the approach and main span structures from abutment to abutment, provide background on alternative project delivery in NY, as well as provide an overview of the design-build process as it was applied to foundation delivery.The 3.1 mile Governor Malcolm Wilson Tappan Zee Bridge was constructed across the Hudson River connecting Nyack and Tarrytown (Rockland and Westchester Counties). Construction started in March 1952 and was completed in 1955 for a cost of $81 million. The seven lane crossing first opened to traffic on December 15, 1955 and coincided with the opening of a 28 mile segment of highway I-87 / I-287 between Suffern NY and Yonkers NY. The bridge is part of the extensive 574 mile New York State Thruway road system owned and operated by the New York State Thruway Authority (NYSTA)."

Jan 1, 2016

By M. H. Govett, G. J. S. Govett

"The current American ""energy crisis"", occurring in the midst of a global debate on the adequacy of mineral supplies to support present and projected levels of world consumption, has focused attention on Canada as a major world producer of minerals. Exports of minerals account for approximately one-third of Canadian foreign earnings; more than half of these exports are to the United States. Although the United States is a net importer of most industrially important metals, with the exception of nickel and zinc, only a small part of American mineral imports are from Canada; these imports are minerals for which geographical proximity and strategic considerations are important. In the short-term, Canada is more dependent on her exports to the U.S. than America is on imports from Canada. It is argued that Canada, far from indulging in economic nationalism to preserve her resources, should expand her exports while the markets are available."

Jan 1, 1973

By J. D. Forrester

In striving to develop this discussion about "Manpower for Industrial Mineral Industries" two fundamental classes of manpower are encountered. These are: 1) The Labor Force, comprised of unskilled and semi-skilled, nonprofessional personnel who participate in conducting economic, mineral deposit operations and; 2) The Professional People involved in the science, engineering, and management of such industrial enterprises. The commentary given here will be directed primarily to a review of the characteristics of the second or latter class. To pursue successfully a career as a scientist or engineer in today's industrial and social complex, it is necessary that technical knowledge must have been acquired by training and study in an institution of higher learning. Also, to act effectively, the individual must have achieved some degree of specialzation, although this element often is developed to most notable degree by post-graduate exposure and experience. In addition, and especially in the case of "management," it is desirable, indeed it is even necessary, that an individual recognize and appreciate the fundamental humanistic-sociological controls, and their nuances, as these elements exist to shape his total environment.

Jan 1, 1969

By Matthew C. Binsfield

The simultaneous electro winning of zinc and manganese from waste water treatment plant sludge was studied as a part of the overall research program, which was conducted to develop the methods for removal of environmentally hazardous metals from the Bunker Hill Superfund Site. This paper discusses the electrolytic method for recovery of zinc and manganese from the solution produced by leaching of sludge with S02 + H2S04. After three stage purification of the leaching solution, zinc and manganese were electro won simultaneously in an undivided electrolytic cell. Zinc was deposited on an aluminum cathode, while manganese was simultaneously produced (as Mn02) on a lead silver anode. The electrowinning parameters studied were the effects of: temperature, current density, electrode material, spacing of electrodes, composition of electrolyte, and electrolyte additives. Anodic and cathodic efficiencies were 30 and 91%, respectively. In light of the process design parameters discussed in the paper, which are affecting the electrowinning, these efficiencies were found as acceptable with regard to the quality and marketability of the products.

Jan 1, 1996

By William E. Ford, Edward Salisbury Dana

1. Simple Hydrocarbons. Chiefly members of the Paraffin Series C,H2,+2. SCHEERERITE. In whitish monoclinic crystals. Perhaps a polymer of marsh-gas (CHI). Found in brown coal at Uznach, Switzerland. HATCHEITITE. Mountain Tallow. In thin plates, or massive. Like soft wax. Color yellowish. Indices, 1.47-1.50. Ratio of C to H = nearly 1 : 1. From the Coal-measures near Merthyr-Tydvil in Glamorganshire, England; from Galicia. PARAFE-IN. A native crystallized paraffin has been described as occurring in cavities in basaltic lava near Paterno, Sicily. Indices, 1.49-1.52. OZOCERITE. Mineral wax in part. Like wax or spermaceti in appearance and consistency. Colorless to white when pure; often leelr-green, yellowish, brownish yellow, brown. Indices, 1.51-1'54. Essentially a paraffin, and consisting chiefly of one of the higher members of the series. Occurs in beds of coal, or associated bituminous deposits, as at Slanik, Moldavia; Roumania; Boryslaw in the Carpathians. Also occurs in southern Utah on a large scale.

Jan 1, 1922

By J. A. Beesley

This paper reviews contemporary international law concerning the seabed, current developments in the United Nations on the seabed, and the main outstanding problems. It emphasizes the importance that the Canadian government attaches to this area.

Jan 1, 1969

By S Mitra, T Singh, D O’Dea, T Honeyands

Permeability and air flow rate in the bed during iron ore sintering is crucial to controlling the sinter quality and productivity of a sinter plant due to its influence on the flame front speed. In the present work, the permeability of the bed during sintering was analysed by means of measured pressure drop and temperature at multiple points in the bed during sintering. Three different zones were categorised, ie humidified (green) bed, region of maximum resistance (high temperature zone) based on temperature, and sintered bed. Previous work has shown that the maximum pressure drop during sintering was due to several concurrent physico-chemical processes including dehumidification, calcination of fluxes, dehydroxylation of goethite, combustion of coke and melting of granules (>1200°C). To quantify the effect of the different process, sintering experiments were conducted in a milli-pot (diameter 53 mm, height 400 mm) with pressure and temperature measured at same location in bed. The milli-pot was fitted with four equidistant (80 mm apart) taps. Overall, five sections in the milli-pot were analysed for pressure drop at different times during sintering. It was found that in region of maximum resistance, coke combustion and flux calcination were highest contributors with ~35 per cent of the pressure drop when compared to other processes like de-humidification and goethite dehydroxylation which contributed to ~20 per cent and 25 per cent each respectively. The pressure drop contribution of the coke combustion region increased with increasing coke addition rate.

Nov 8, 2021

By Hornsey R., P. van der Merwe

The Two Rivers Project is a feasibility study to evaluate the UG2 chromitite layer on Dwarsrivier372KT, Mpumalanga Province, South Africa. The project, which commenced in August 2001, is expected to receive go-ahead early in 2003. The project sponsors (AVMIN 55%, Implats 45%)required project delivery within a short timeframe requiring optimization of the geological and geostatistical programme. Geological modelling was carried out in parallel to the drilling programme, and significant up-front geostatistical preparatory work was done. The time saving was approximately 4 – 6 months on project delivery. The cost saving to the project (excluding NPV considerations) is estimated at R20–30 million. Keywords; Two Rivers Platinum, Dwarsrivier 372KT, UG2 chromitite layer.

Jan 1, 2003

If the industry keeps doing what it has always done, it will continue to get what it has always got - rising operating costs. Why is this so? Generally grades being chased are becoming lower, stripping ratios becoming higher, ability to attract personnel to the industry becoming harder and/or more expensive, higher safety standards are being demanded and environmental governance is being enforced.   How then should the surface mining industry plan for the future whilst delivering on improved safety and the environment? In-pit crushing and conveying (IPCC) points the way, as a partial or complete substitute for trucks.   IPCC systems promise significant advantages over traditional truck and shovel operations, including improved safety, reduced operating costs, reduced dust and noise emissions, far greater efficiency in energy use (electric versus diesel motors predominantly and the ability to regenerate electricity back into the local grid for downhill situations), reduced carbon emissions (dependent on power generation source) and reduced water consumption. Despite these advantages, there is a general industry reluctance to migrate from truck and shovel operations. This reluctance stems from a familiarity with truck and shovel operations and a perceived concern that IPCC lacks flexibility which will negatively impact on the mining operation.   In studies conducted since 2007 (with the new modular builds) comparing IPCC with truck-optimised pit designs, IPCC has delivered up to USD$0.82 per tonne moved less than an equivalent truck operation. In addition, IPCC is easily automated from a central control room (local or remote) - something that trucks have yet to commercially achieve.   IPCC is a proven process that, with a fresh mindset, can make a significant improvement to mining operations - its safety, the impact on the environment and its costs. It maybe of interest to note that there is over 200 IPCC installations worldwide today.   This paper and presentation will assist in furthering the understanding of IPCC and its applicability.

Jun 1, 2010

By Hugh S. Spence

IN MAY, 1930, G. LaBine and E. C. St. Paul, prospect¬ing round the southeastern shore of Great Bear Lake, in the North West Territories of Canada, discovered pitchblende at what is now LaBine Point. At the same time, they also found native silver in a small sheared break on an island lying off the point. Late in 1930, samples of the pitchblende were sent to the Mines Branch, at Ottawa. The material consisted of several fair-sized slabs of botryoidal pitchblende banded with a brownish quartz. A small amount of chalcopyrite was visible as small particles and fine veinlets, and the pieces were rather heavily stained a yellowish-green by secondary copper-uranium salts. Analyses were run in the Mines Branch Ore Dressing Laboratories on two samples, and small-scale concentration tests were made on one of them. The results of this work were published in a Memorandum Series report (No. 48) of the Mines Branch, in March, 1931.

Jan 1, 1932

By Lloyd E. Haight

After accepting the invitation to make this appearance today, it occurred to me that the subject matter which had been assigned to me, namely, the purpose and role of an advisor, was, contrary to what; some people might think, a controversial subject. In my brief lifetime, I have discovered that the world is full of advisors; that is to say, there are many people who undertake to render advice concerning subject matters upon which they may, or may not be qualified to speak. It shall be my purpose today to set forth what now appears to be the function of the members of the Advisory Council to the U. S. Public Land Law Review Commission; and, in so doing, I hope that I do not offend the Commission or any other-member of the Advisory Council with whom I serve. It has always been my personal conception of the role of an advisor that he should tender advice when it is requested, and then only if he has prepared himself concerning the matter upon which the advice is being given. I am sure it was the Congressional intent at the time the Public Land Law Review Commission was established indeed it was the hope. of Congress--that those of us who were to become members of the Advisory Council were informed upon certain particular subjects and then at the proper time express our opinions upon these subjects-and, by the same token, not attempt to enter opinions upon problems with which we have no experience in theory or in actuality. Some wag once said that if Columbus had had an advisory council, he would still be waiting at the dock in Spain, and there is more truth than fiction in that statement. With this problem in mind, let us examine the purpose of the Advisory Council itself.

Jan 1, 1967

By H. O. Seigel

This is an introductory paper on a new method of prospecting for mineral deposits which has been developed by Scintrex Limited. The method, which we call Luminex, for luminescent mineral exploration, is based on time- resolved mineral luminescence created by an ultraviolet light source. It has the ability to detect and resolve a group of key minerals which are either ore minerals themselves, or more often, are accessory or pathfinder minerals for certain types of economic ore deposits. Fortunately, these minerals are commonly found at the earth's surface, even in areas of considerable weathering. The method extends the range of mineral deposits which are remotely detectable from the air to include those such as tungsten, tin, molybdenum, gold and bedded lead-zinc deposits and, is therefore, a natural supplement to our three classical methods of airborne geophysics.

Jan 1, 1983