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USGS1988

Natural aggregates of the conterminous United States

Crushed stone and sand and gravel are the two main sources of natural aggregates. These materials are commonly used construction materials and frequently can be interchanged with one another. They are widely used throughout the United States, with every State except two producing crushed stone. Together they amount to about half the mining volume in the United States. Approximately 96 percent of sand and gravel and 77 percent of the crushed stone produced in the United States are used in the construction industry. Natural aggregates are widely distributed throughout the United States in a variety of geologic environments. Sand and gravel deposits commonly are the results of the weathering of bedrock and subsequent transportation and deposition of the material by water or ice (glaciers). As such, they commonly occur as river or stream deposits or in glaciated areas as glaciofluvial and other deposits. Crushed stone aggregates are derived from a wide variety of parent bedrock materials. Limestone and other carbonates account for approximately three quarters of the rocks used for crushed stone, with granite and other igneous rocks making up the bulk of the remainder. Limestone deposits are widespread throughout the Central and Eastern United States and are scattered in the West. Granites are widely distributed in the Eastern and Western United States, with few exposures in the Midwest. Igneous rocks (excluding granites) are largely concentrated in the Western United States and in a few isolated localities in the East. Even though natural aggregates are widely distributed throughout the United States, they are not universally available for consumptive use. Some areas are devoid of sand and gravel, and potential sources of crushed stone may be covered with sufficient unconsolidated material to make surface mining impractical. In some areas many aggregates do not meet the physical property requirements for certain uses, or they may contain mineral constituents that react adversely when used as concrete aggregate. In areas where suitable natural aggregate is not available or accessible, it may become necessary to improve the quality of existing aggregate, to import aggregate from outside the area, or to substitute artificial aggregate for natural aggregate. In most cases, all of these alternatives add substantially to the cost of the final product. Even though an area may be blessed with an abundance of aggregate suitable for the intended purpose, existing land uses, zoning, or regulations may preclude commercial exploitation of the aggregate. This report also discusses the aggregate industry in general terms, including exploration, mining, and processing, as well as aggregate production rates. Proper long-range planning based on an understanding of the aggregate industry can help assure adequate supplies of aggregate.

conterminous United States↗
USGS2017

Vanadium

Vanadium is used primarily in the production of steel alloys; as a catalyst for the chemical industry; in the making of ceramics, glasses, and pigments; and in vanadium redox-flow batteries (VRBs) for large-scale storage of electricity. World vanadium resources in 2012 were estimated to be 63 million metric tons, which include about 14 million metric tons of reserves. The majority of the vanadium produced in 2012 was from China, Russia, and South Africa. Vanadium is extracted from several different types of mineral deposits and from fossil fuels. These deposits include vanadiferous titanomagnetite (VTM) deposits, sandstone-hosted vanadium (with or without uranium) deposits (SSV deposits), and vanadium-rich black shales. VTM deposits are the principal source of vanadium and consist of magmatic accumulations of ilmenite and magnetite containing 0.2 to 1 weight percent vanadium pentoxide (V 2 O 5 ). SSV deposits are another important source; these deposits have average ore grades that range from 0.1 to greater than 1 weight percent V 2 O 5 . The United States has been and is currently the main producer of vanadium from SSV deposits, particularly those on the Colorado Plateau. Vanadium-rich black shales occur in marine successions that were deposited in epeiric (inland) seas and on continental margins. Concentrations in these shales regularly exceed 0.18 weight percent V 2 O 5 and can be as high as 1.7 weight percent V 2 O 5 . Small amounts of vanadium have been produced from the Alum Shale in Sweden and from ferrophosphorus slag generated during the reduction of phosphate to elemental phosphorus in ore from shales of the Phosphoria Formation in Idaho and Wyoming. Because vanadium enrichment occurs in beds that are typically only a few meters thick, most of the vanadiferous black shales are not currently economic, although they may become an important resource in the future. Significant amounts of vanadium are recovered as byproducts of petroleum refining, and processing of coal, tar sands, and oil shales may be important future sources. Vanadium occurs in one of four oxidation states in nature: +2, +3, +4, and +5. The V 3+ ion has an octahedral radius that is almost identical to that of (Fe 3+ ) and (Al 3+ ) and, therefore, it substitutes in ferromagnesian minerals. During weathering, much of the vanadium may partition into newly formed clay minerals, and it either remains in the +3 valence state or oxidizes to the +4 valence state, both of which are relatively insoluble. If erosion is insignificant but chemical leaching is intense, the residual material may be enriched in vanadium, as are some bauxites and laterites. During the weathering of igneous, residual, or sedimentary rocks, some vanadium oxidizes to the +5 valence state, especially in the intensive oxidizing conditions that are characteristic of arid climates. The average contents of vanadium in the environment are as follows: soils [10 to 500 parts per million (ppm)]; streams and rivers [0.2 to 2.9 parts per billion (ppb)]; and coastal seawater (0.3 to 2.8 ppb). Concentrations of vanadium in soils (548 to 7,160 ppm) collected near vanadium mines in China, the Czech Republic, and South Africa are many times greater than natural concentrations in soils. Additionally, if deposits contain sulfide minerals such as chalcocite, pyrite, and sphalerite, high levels of acidity may be present if sulfide dissolution is not balanced by the presence of acid-neutralizing carbonate minerals. Some of the vanadium-bearing deposit types, particularly some SSV and black-shale deposits, contain appreciable amounts of carbonate minerals, which lowers the acid-generation potential. Vanadium is a micronutrient with a postulated requirement for humans of less than 10 micrograms per day, which can be met through dietary intake. Primary and secondary drinking water regulations for vanadium are not currently in place in the United States. Vanadium toxicity is thought to result from an intake of more than 10 to 20 milligrams per day. Vanadium is essential for some biological processes and organisms. For example, some nitrogen-fixing bacteria require vanadium for producing enzymes necessary to convert nitrogen from the atmosphere into ammonia, which is a more biologically accessible form of nitrogen.

Professional Paper↗
USGS2014

Quality of water in the northwest

Abstract The quality of natural waters, as judged by the dissolved mineral content, is quite varied throughout the Northwest. The concentrations of dissolved solids range from less than 50 ppm for many of the surface waters in Washington and Oregon, to several thousand ppm in the alkaline lakes of these states. On the whole, the quality of the natural waters is good but in some areas the waters have become unsatisfactory for many purposes, including irrigation, through contamination with wastes from industrial processes, which may include drainage from irrigated lands.

Oregon, Washington↗
USGS1976

Water resources of Lincoln County coastal area, Oregon

The Lincoln County coastal area is underlain by Tertiary volcanic and sedimentary rocks of low permeability that store only a small volume of the annual precipitation which averages 68 inches (1,730 millimeters). Consequently, the Tertiary units yield small quantities of water to wells and furnish little ground-water discharge to maintain the base flow of streams. Although streamflow is normally abundant during the wet season, flow decreases greatly during summer when needed most. Quaternary marine terrace deposits of semiconsolidated sand border the western part of the area and are the most productive aquifers. Several wells drilled into the Quaternary deposits are among the highest producing wells of the area, with yields of 25 to 60 gallons per minute (1.6 to 3.8 liters per second). The Siletz River Volcanics is one of the better aquifers in the area and generally yields water in volumes sufficient for domestic use. The average well drilled into these rocks yields 5 to 10 gallons per minute (0.3 to 0.6 liters per second). Locally, this formation is quite permeable and has a producing well in the study area, with a yield of 120 gallons per minute (7.6 liters per second). Other volcanic rocks of small areal extent and largely untested, are the basalts near Depoe Bay, Cape Foulweather, Yachats, and Cape Perpetua. Wells drilled in January 1976 near Depoe Bay indicate that as much as 125 gal/min (10 L/s) of water can be obtained from wells drilled into the basalt. Tertiary marine sedimentary rocks of siltstone and sandstone are widespread throughout the area. Yields of wells drilled in these rocks are generally low (less than 5 gallons per minute, or 0.3 liters per second), and many wells in these formations produce no usable quantities of ground water. Approximately 5,000,000 acre-feet (6,000 cubic hectometers) of water discharges annually into the Pacific Ocean from all streams along the Lincoln County coast. About 85 percent of the annual streamflow occurs from November through April. Minimum streamflaws occur from August through October when, at times, as little as 450 acre-feet (55 hectometers) per day flows from all streams. Most of the ground water, with the exception of water from some wells drilled in the marine siltstone and sandstone, contains relatively small concentrations of dissolved minerals. Wells that tap the marine deposits at low altitudes have high concentrations of dissolved minerals, particularly sodium and chloride. In general, analyses of water from the 14 streams sampled in Lincoln County show very good chemical quality. The iron content of Depoe and Thiel Creeks is above the Environmental Protection Agency's recommended limit of 0.3 milligrams per liter for drinking water. Annual water use totals 6.7 billion gallons, which is less than 0.5 percent of runoff. About 70 percent of the use is for industrial purposes at one lumber products mill, about 25 percent is for public supplies, and less than 5 percent for irrigation. Water supplies for all municipalities in Lincoln County currently (1975) are obtained from surface-water sources. Because of rapid economic development of the coastal area, it is expected that additional water will be needed in the future. Additional water can be supplied (1) by reservoirs on major streams; (2) by the expansion, in some locations, of present surface-water facilities on small streams; and (3) locally, by an additional small volume of supplemental water from ground-water sources.

Oregon↗
USGS1969

Water resources of Clark, Cleveland, and Dallas Counties, Arkansas

Clark, Cleveland, and Dallas counties constitute an area of 2,151 square miles in south-central Arkansas. The area is in two physiographic provinces--the Ouachita Mountains of the Ouachita province of the Interior Highlands, and the West Gulf Coastal Plain of the Coastal Plain province. The area is drained by the Ouachita, Saline, and Little Missouri Rivers and their tributaries. Although some of the streams in the project area can furnish dependable water supplies without storage, the amount of water available for use can be increased by the construction of reservoirs. The average surface-water yield in the area is about 1.4 cubic feet per second per square mile, or a total of about 3,000 cubic feet per second. Generally, the water quality is good; but water from some of the streams, particularly from the smaller tributaries, may require treatment for excessive iron content and high color. Ground-water yields in the project area vary considerably. The consolidated rocks in the Interior Highlands generally yield less than 10 gallons per minute to wells, precluding the development of large municipal or industrial groundwater supplies in that area. Of the 17 geologic units present in the Coastal Plain part of the project area, 12 yield water but in varying amounts. Among the formations of Cretaceous age, the Tokio yields good-quality water in the outcrop, but the quality deteriorates downdip; the Brownstown Marl yields small amounts of water for domestic purposes, mainly in the outcrop area ; the Ozan Formation yields a highly mineralized water that is generally unsuitable for most purposes; the Nacatoch Sand yields as much as 100 gallons per minute of good-quality water in and near the outcrop, but the water becomes very salty and corrosive at distances ranging from 2 miles downdip from the outcrop in northern Clark County to 17 miles downdip in the southern part of the county. The formations of Tertiary age offer the best possibilities for ground water, particularly in Dallas and Cleveland Counties. The Wilcox Group contains no thick widespread sands but contains thin sands locally. The quality of the water tends to deteriorate downdip, as the water becomes more mineralized and changes from a bicarbonate to a chloride type. The Carrizo Sand is undeveloped but may yield several gallons of water per minute per foot of drawdown in a large part of these two counties. High iron content may be a problem in water from the Carrizo. The Cane River Formation yields 50 gallons per minute of good-quality water to each of two wells at Sparkman. Elsewhere, high iron content of the water may be a problem. The Sparta Sand is the best aquifier in the project area, particularly east of central Dallas County. Well yields of 700 gallons per minute or more are possible. With minor treatment, the water is suitable for most purposes. The Cockfield Formation is utilized mainly for domestic supplies, but where the sands are thick, yields of as much as 300 gallons per minute are possible. The Jackson Group is utilized mainly for domestic supplies. In some areas, water from this unit contains such a high concentration of sulfate that it is unpalatable. The deposits of Quaternary age are thin and generally suitable only for domestic supplies. However, several wells that yield more than 200 gallons per minute have been developed in the alluvium south of Arkadelphia. Transmissibility values are highly variable, and test drilling is advisable to determine if large amounts of water are available at any specific site. Total water use in the project area in 1965 was about 6 million gallons per day, an increase of about 0.6 million gallons per day since 1960). Slightly more than one-half this amount was derived from surface-water sources. Total water use in the area in 1967 was insignificant compared with the total water available. DeGray Reservoir, now under construction on the Caddo River, will provide 250 million gallons per day for water

Water Supply Paper↗
USGS2015

Mineral resource of the month: silver

Silver, one of the eight precious or noble metals, has been used extensively throughout recorded history for various medical purposes, ornaments and utensils, and for its intrinsic value as the basis for trade and monetary systems. Silver has played a significant role in world history, financing a Greek victory over the Persians in 480 B.C., helping Spain become a world power in the 16th and 17th centuries, and helping fund the Union forces during the U.S. Civil War, to give a few examples. Silver occurs as a native metal; in sulfide ores of copper, lead and zinc; and sometimes with bismuth and antimony. Silver is always present in ores containing gold. The Silver Institute estimated that, in 2013, about 29 percent of global mined silver came from silver ores, 38 percent came from lead-zinc ores, 20 percent came from copper ores and 13 percent came from gold ores. Silver's properties include its ability to endure extreme temperatures, its high reflectance of light, its thermal and electrical conductivity (the highest of all metals), and its strength, malleability and ductility. Demand for silver arises from three areas: industrial applications (in electronics, brazing alloys and solders, photography and other uses), investment (including coins and bars), and silver jewelry and decor (including silverware). Silver-halide X-rays were long the standard, but are now being replaced by digital imaging technology. Since 2000, demand for silver in photographic applications has also declined owing to the use of digital photography. In 2013, uses in electronics accounted for 42 percent of U.S. silver consumption; coins and metals for 35 percent; photography for 13 percent; jewelry and silverware for 7 percent; and other uses for 3 percent. Silver is also used in solar power generation: 90 percent of crystalline silicon photovoltaic solar cells use silver paste. On windows, a transparent layer of silver reflects up to 95 percent of sunlight, saving energy. In water purification, use of silver eliminates the need for corrosive chlorine. For more information on silver and other mineral resources, visit: http://minerals.usgs.gov/minerals .

Earth↗
USGS2018

International Limnogeology Congress (ILIC6), Reno USA, special issue on new limnogeological research focused on Holocene lake systems

The 6th International Limnogeology Congress (ILIC6) of the International Association of Limnogeology (IAL) was held in Reno, Nevada, USA 15–19 June, 2015. The successful congress brought together a wide variety of academic, government, and industry participants from 20 countries and six continents. The highpoint of the four-day meeting were eight keynote addresses highlighting cutting-edge research in paleolimnology and limnogeology. These addresses were often the focal point of discussions throughout the congress. Among the topics covered in the more than 140 poster presentations included the use of biological proxies to identify paleoenvironmental change due to natural variability and human impact, the evolution of mineral formation in saline lakes, sedimentation deposition processes in Mesoproterozoic lakes, the role of groundwater in lacustrine hydrology, and organic and inorganic contaminant histories in modern lakes.

Conference Paper↗
USGS1994

Airborne remote sensing for geology and the environment; present and future

In 1988, a group of leading experts from government, academia, and industry attended a workshop on airborne remote sensing sponsored by the U.S. Geological Survey (USGS) and hosted by the Branch of Geophysics. The purpose of the workshop was to examine the scientific rationale for airborne remote sensing in support of government earth science in the next decade. This report has arranged the six resulting working-group reports under two main headings: (1) Geologic Remote Sensing, for the reports on geologic mapping, mineral resources, and fossil fuels and geothermal resources; and (2) Environmental Remote Sensing, for the reports on environmental geology, geologic hazards, and water resources. The intent of the workshop was to provide an evaluation of demonstrated capabilities, their direct extensions, and possible future applications, and this was the organizational format used for the geologic remote sensing reports. The working groups in environmental remote sensing chose to present their reports in a somewhat modified version of this format. A final section examines future advances and limitations in the field. There is a large, complex, and often bewildering array of remote sensing data available. Early remote sensing studies were based on data collected from airborne platforms. Much of that technology was later extended to satellites. The original 80-m-resolution Landsat Multispectral Scanner System (MSS) has now been largely superseded by the 30-m-resolution Thematic Mapper (TM) system that has additional spectral channels. The French satellite SPOT provides higher spatial resolution for channels equivalent to MSS. Low-resolution (1 km) data are available from the National Oceanographic and Atmospheric Administration's AVHRR system, which acquires reflectance and day and night thermal data daily. Several experimental satellites have acquired limited data, and there are extensive plans for future satellites including those of Japan (JERS), Europe (ESA), Canada (Radarsat), and the United States (EOS). There are currently two national airborne remote sensing programs (photography, radar) with data archived at the USGS' EROS Data Center. Airborne broadband multispectral data (comparable to Landsat MSS and TM but involving several more channels) for limited geographic areas also are available for digital processing and analysis. Narrow-band imaging spectrometer data are available for some NASA experiment sites and can be acquired for other locations commercially. Remote sensing data and derivative images, because of the uniform spatial coverage, availability at different resolutions, and digital format, are becoming important data sets for geographic information system (GIS) analyses. Examples range from overlaying digitized geologic maps on remote sensing images and draping these over topography, to maps of mineral distribution and inferred abundance. A large variety of remote sensing data sets are available, with costs ranging from a few dollars per square mile for satellite digital data to a few hundred dollars per square mile for airborne imaging spectrometry. Computer processing and analysis costs routinely surpass these expenses because of the equipment and expertise necessary for information extraction and interpretation. Effective use requires both an understanding of the current methodology and an appreciation of the most cost-effective solution.

Bulletin↗
USGS2015

Studies by the U.S. Geological Survey in Alaska, Volume 15

Summary Professional Paper 1814— Studies by the U.S. Geological Survey in Alaska, Volume 15 —continues a long-running series of collected volumes of U.S. Geological Survey (USGS) scientific reports on Alaska. This series presents new and sometimes preliminary findings that are of interest to Earth and biological scientists in academia, government, and industry; to land and resource managers; and to the general public. The series covers a broad spectrum of scientific topics, from various parts of Alaska, serving to emphasize the diversity of USGS efforts to meet the Nation’s needs for Earth-science information in the State. The USGS provides reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

Professional Paper↗
USGS2014

Structural control of ore deposition at Kasaan Peninsula, southeastern Alaska

Copper‐bearing magnetite deposits and associated copper deposits at Kasaan Peninsula , Prince of Wales Island, southeastern Alaska , have been known for many years and have been mined to some extent for their copper content. At the beginning of World War II, the development of war industries in the Pacific northwest focused attention on the deposits as possible sources of iron ore . From 1942 through 1944 the United States Geological Survey made detailed studies of most of the ore deposits and at a few of the more promising localities diamond‐drilling operations were carried on by the United States Bureau of Mines. The deposits are for the most part small and irregular but of relatively high grade. The chief ore minerals are magnetite, pyrite, and chalcopyrite, and the gangue consists largely of skarn minerals, including garnet, epidote, diopside, and hornblende. The deposits are presumably of pyrometasomatic origin, but whereas deposits of this type are commonly replacement bodies in limestone, at Kasaan Peninsula limestone seemingly was a poor host rock for the ore.

Alaska↗
USGS1952

Stratigraphic sections of the Phosphoria formation in Idaho, 1947-48, Part I

The Permian Phosphoria formation of the western states contains one of the world's largest reserves of phosphate. Although previous investigations (see especially Mansfield, 1927), including reconnaissance geologic mapping and sampling, established the location of most of the important deposits and their quality of scattered localities, they were not sufficiently detailed to permit a comparison of the merits of individual deposits or an appraisal of the reserves of phosphate rock that might be available under present economic conditions. Because the growing importance of the western phosphate deposits requires a better, more detailed understanding of their distribution and quality, the Geological Survey began in 1947 a comprehensive investigation, including (1) reconnaissance geologic mapping, mostly in Montana, of areas in which the Phosphoria formation could occur but where it had not previously been looked for or found; (2) geologic mapping, mostly in Montana, at a scale no smaller than 1:62,500, of several areas known to contain the Phosphoria formation but not previously mapped except in reconnaissance fashion; (3) geologic and topographic mapping, at a scale of 1:12,000, of some of the richest, thickest, and most accessible deposits; (4) measuring, describing, and sampling all beds of the phosphatic and shaly parts, and in some places the full thickness, of the Phosphoria formation and its stratigraphic equivalents at one or two localities per township over the entire field; (5) chemical and spectrographic analysis of the samples for phosphate, fluorine, minor metals, oil, and rock-forming constituents; and (6) petrologic and geochemical studies of the rocks and minerals of the formation. These studies are designed to define the regional and local geologic structures in which the phosphate bed lie, to provide a basis for the estimation of reserves of the inferred class over the entire region, and to determine the origin of the rocks and the elements contained in them. The data collected are not of the detail required to plan actual mining operations, but it is hoped they will guide industry in the selection of individual deposits worthy of further exploration. Most of the field work contemplated as a part of this investigation is now completed. Although the data will not be compiled or published in final form for some years to come, segments of the data, accompanied by little or no interpretation, will be published as preliminary maps or reports as they are assembled. The present report is the first of a series presenting in abbreviated form the description and analyses of the beds measured and sampled at various localities in southeastern Idaho (pl. 1). Companion reports presenting segments of the data from Montana, Wyoming, and Utah (Swanson and others, 1952, and McKelvey and others, 1952a and 1952b) are being released at the same time as this report, and others are in preparation.

Idaho↗
USGS1983

Hydrogeologic and water-quality characteristics of the Mount Simon-Hinckley aquifer, southeast Minnesota

The Mount Simon-Hinckley aquifer in southeast Minnesota consists of a thick sequence of sandstone that generally yields large quantities of good-quality water to wells. The aquifer is most important as a source of water supply in the Twin Cities area, where it supplies approximately 10 percent of the ground water used. It is the uppermost bedrock aquifer and, locally, the principal source of domestic supply where it is present north of the Twin Cities. Yield to wells are generally about 500 gallons per minute but may be as high as 2,000 gallons per minute. The aquifer is a good potential source of water because of (1) large quantities of water in storage, (2) adequate yields to wells, and (3) good water quality. The quality of water in the aquifer is generally acceptable for municipal, industrial, and domestic uses. The dissolved-solids concentration in water from the aquifer ranges from a minimum of 48 milligrams per liter to a maximum of 2,810 milligrams per liter. The lowest values are in the eastern and northern parts of the aquifer, where bedrock is at or close to land surface. The highest concentrations are in the southwestern part of the aquifer, where leakage from over lying Cretaceous rocks is highly mineralized water. Magnesium and sulfate concentrations are also high in the southwest. The dissolved-solids concentration generally increases with depth in the aquifer. The predominant water type in the aquifer is calcium magnesium bicarbonate, although sodium chloride waters are present at depth and in the discharge areas along large rivers. This report is one of a series of the hydrogeology and water quality of the 14 principal aquifers in Minnesota prepared by the U.S. Geological Survey. The U.S. Environmental Protection Agency requested these studies because of the need for information to develop its Underground Injection Control Program.

Minnesota↗
USGS2007

Proceedings for a workshop on deposit modeling, mineral resource assessment, and their role in sustainable development

The world's use of nonfuel mineral resources continues to increase to support a growing population and increasing standards of living. The ability to meet this increasing demand is affected especially by concerns about possible environmental degradation associated with minerals production and by competing land uses. What information does the world need to support global minerals development in a sustainable way? Informed planning and decisions concerning sustainability and future mineral resource supply require a long–term perspective and an integrated approach to resource, land use, economic, and environmental management worldwide. Such perspective and approach require unbiased information on the global distribution of identified and especially undiscovered resources, the economic and political factors influencing their development, and the potential environmental consequences of their exploitation. The U.S. Geological Survey and the former Deposit Modeling Program of the International Union of Geological Sciences (IUGS) of the United Nations Educational, Scientific and Cultural Organization (UNESCO) sponsored a workshop on "Deposit Modeling, Mineral Resource Assessment, and Their Role in Sustainable Development" at the 31st International Geological Congress (IGC) in Rio de Janeiro, Brazil, on August 18–19, 2000. The purpose of the workshop was to review the state-of-the-art in mineral deposit modeling and resource assessment and to examine the role of global assessments of nonfuel mineral resources in sustainable development. The workshop addressed questions such as the following: Which of the available mineral deposit models and assessment methods are best suited for predicting the locations, deposit types, and amounts of undiscovered nonfuel mineral resources remaining in the world? What is the availability of global geologic, mineral deposit, and mineral exploration information? How can mineral resource assessments be used to address economic and environmental issues? Presentations included overviews of assessment methods applied in previous national and other small-scale assessments of large regions and of the resulting assessment products and their uses. Twenty-seven people from Canada, China, Finland, Germany, Japan, Peru, Slovenia, South Africa, United States, and Venezuela participated in the 2-day post-Congress workshop. The attendees represented academia, government, environmental organizations, and the mining industry.

Circular↗
USGS1979

Radioactive springs geochemical data related to uranium exploration: basic data and use of multivariate factor scores

Radioactive springs and wells at 33 localities in the States of Colorado, Utah, Arizona, and New Mexico have been studied and sampled to obtain geochemical data to determine whether such data are useful in a uranium exploration program. Most samples were collected from mineral-rich springs probably related to hydrothermal systems of various ages. Two sets of data were obtained, the first based on the chemical composition and physical and chemical properties of spring and ground water, and the second based on the chemical composition of mineral precipitates deposited by radioactive springs. Multivariate statistical analysis of the water data suggests four major geochemical factors affecting the 23 parameters measured. These factors were labeled as total dissolved solids, alkalinity, temperature, and Fe-U concentration. Multivariate statistical analysis of the precipitate data suggests five factors affecting the 32 element values measured. These factors were labeled as mineral contamination, Mn precipitation, Fe-As-Be precipitation, heavy metals precipitation, and Ba-Ra precipitation. Relative intensities of the geochemical processes represented by the factors were computed using factor scores. Sample localities were ranked on the basis of relative intensities, and the five localities with the highest intensities were selected as being the most favorable for more intensive exploration for uranium. Immediate use of such selection would be experimental because of the lack of industry experience at this time in the exploration of active hydrothermal systems for uranium.

Open-File Report↗
USGS2005

Mineral commodity profiles: Germanium

Overview -- Germanium is a hard, brittle semimetal that first came into use a half-century ago as a semiconductor material in radar units and as the material from which the first transistor was made. Today it is used principally as a component of the glass in telecommunications fiber optics; as a polymerization catalyst for polyethylene terephthalate (PET), a commercially important plastic; in infrared (IR) night vision devices; and as a semiconductor and substrate in electronics circuitry. Most germanium is recovered as a byproduct of zinc smelting, although it also has been recovered at some copper smelters and from the fly ash of coal-burning industrial powerplants. It is a highly dispersed element, associated primarily with base-metal sulfide ores. In the United States, germanium is recovered from zinc smelter residues and manufacturing scrap and is refined by two companies at four germanium refineries. One of the four refineries is dedicated to processing scrap. In 2000, producers sold zone-refined (high-purity) germanium at about $1,250 per kilogram and electronic-grade germanium dioxide (GeO2) at $800 per kilogram. Domestic refined production was valued at $22 million. Germanium is a critical component in highly technical devices and processes. It is likely to remain in demand in the future at levels at least as high as those of 2000. U.S. resources of germanium are probably adequate to meet domestic needs for several decades.

Open-File Report↗
USGS2005

Sources of nitrate in the Arno River waters: Constraints from d 15 N and d 18 O

Running waters in anthropogenically affected areas are susceptible to nitrate contamination. Source identification is a fundamental step for the development of effective remediation. Previous studies pointed to pollution by nitrogen-bearing contaminants in the Arno Basin. In this paper, eleven surface water samples have been analysed for main and trace components and 15 N/ 14 N and 18 O/ 16 O ratios, with the aim of identifying for the first time the origin of nitrate in the Arno River Basin so that further investigations can appropriately be designed. d 18 O(NO 3 )and d 15 N(NO 3 ) values have allowed to hypothesise the main sources of nitrate, as follows: i) mineralized fertilizer, ii) soil-organic nitrogen, iii) manure and septic waste. The anomalously high d 15 N and d 18 O values in the Chiana ( d 15 N=24.9‰ and d 18 O=15.5‰) and Usciana tributaries ( d 15 N=30.1‰ and d 18 O=7.2‰) show a low probability of belonging to the same population as that of the other samples and can be related to denitrification process of nitrate from animal waste/sewage and/or an industrial process (e.g. tanneries).

GeoActa↗
USGS1985

USGS research on mineral resources, 1985 program and abstracts

The extended abstracts in this volume are summaries of the papers presented orally and as posters in the first V.E. McKelvey Forum on Mineral and Energy Resources, entitled "USGS Research on Mineral Resources-1985." The Forum has been established to improve communication between the USGS and the earth science community by presenting the results of current USGS research on nonrenewable resources in a timely fashion and by providing an opportunity for individuals from other organizations to meet informally with USGS scientists and managers. It is our hope that the McKelvey Forum will help to make USGS programs more responsive to the needs of the earth science community, particularly the mining and petroleum industries, and will foster closer cooperation between organizations and individuals.

Circular↗
USGS1999

Coal-fired power generaion, new air quality regulations, and future U.S. coal production

Tighter new regulation of stack gas emissions and competition in power generation are driving electrical utilities to demand cleaner, lower sulfur coal. Historical data on sulfur content of produced coals shows little variability in coal quality for individual mines and individual coal-producing counties over relatively long periods of time. If coal-using power generators follow the compliance patterns established in Phase I of the 1990 Clean Air Act Amendments, then the industry's response to the tighter Phase II emissions standards will result in large amounts of coal production shifting from higher sulfur areas to areas with lower cost low sulfur coal. One reason this shift will likely occur is that currently only 30% of U.S. coal-fired electrical generating capacity is equipped with flue-gas scrubbers. In 1995, coal mines in the higher sulfur areas of the Illinois Basin and Northern and Central Appalachia employed 78% of all coal miners (>70,000 miners). A substantial geographical redistribution of the nation's coal supplies will likely lead to economic dislocations that will reach beyond local coal-producing areas.

Environmental Geosciences↗