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At least 595 records · Page 33Linked to original sources
USGS1995

Structure of the basins and ranges, Southwest New Mexico, an interpretation of seismic velocity sections

This report presents a geologic appraisal of seismic velocity sections that profile a total of 790 km in southwest New Mexico west of Las Cruces and south of Lordsburg and Deming. The present work outlines the contribution of these velocity sections to estimating areas favorable for mineral resource occurrences. Seismic refraction surveys are carried out with the initial goal of estimating the subsurface distribution of acoustic compressional velocity (Vp), which may ultimately be interpreted to provide information on lithology, geologic structure, and the occurrence of natural resources. The seismic sections presented here show velocity detail having dimensions of 100's to 1000's of meters to a depth of about 2.5 km, and across a net of traverses that profile most basins well as several ranges in the study area. Figure 1 shows the location of the seismic refraction lines. The lines are designated 1, 2, 3, 4, 5, and 7; there is no line 6. The survey covers a broad swath of the southwest Basin and Range Province extending from the Arizona border eastward to the Rio Grande River, and from the Mexican border to about lat. 32° 30' N. Lines 1, 3, and 7 traverse the axis of basins in roughly northsouth directions; the remaining lines 2, 4, and 5 trend east-west and cross various ranges and basins. Seismic data that have been collected in this region include deep-crustal refraction traverses by university scientists and commercial seismic reflection profiles acquired for petroleum exploration. Results of deep-crustal refraction studies are reviewed to provide a regional setting for the higher resolution refraction data. Results from seismic reflection will not be discussed. Industry reflection data in the area are not generally available for non-proprietary use. The nearest reflection data publicly available are in the Socorro area, about 80 km north of the present study area (Brown and others, 1980). These data were acquired by the Consortium for Continental Reflection Profiling (COCORP), a public-supported research group, to investigate the possibility of magma beneath part of the Rio Grande valley. Up to 1978 there were about 36 deep borings in the region of southwest New Mexico (Thompson and others, 1978). This drilling resulted mainly from an evaluation of petroleum potential of the Pedrogosa basin which is an extensive area of Paleozoic subsidence in Arizona, New Mexico, and Mexico that accumulated about three kilometers of Paleozoic sedimentary rock (Zeller, 1965; Thompson and others, 1978). Of these drill holes, 25 are close enough to the present seismic sections to provide correlations of velocity to lithology, and to provide an estimate of the errors associated with depth-to-interface interpretations. This information is summarized prior to considering the implications of the seismic sections in detail. The major portion of the report centers around two plates: Plate I shows seismic lines and selected drill hole locations superimposed on gravity contours, and Plate II shows velocitysections with drill hole summaries. These plates provide the foundation for developing inferences on buried lithologic, structural, and mineral resources for the region.

New Mexico↗
USGS2006

Drivers of U.S. mineral demand

Introduction: The word 'demand' has different meanings for different people. To some, it means their 'wants and needs,' to others it is what they consume. Yet, when considering economics, demand refers to the specific amounts of goods or services that individuals will purchase at various prices. Demand is measured over a given time period. It is determined by a number of factors including income, tastes, and the price of complementary and substitute goods. In this paper, the term consumption is used fairly synonymously with the term demand. Most mineral commodities, like iron ore, copper, zinc, and gravel, are intermediate goods, which means that they are used in the production of other goods, called final goods. Demand for intermediate goods is called derived demand because such demand is derived from the demand for final goods. When demand increases for a commodity, generally the price rises. With everything else held constant, this increases the profits for those who provide this commodity. Normally, this would increase profits of existing producers and attract new producers to the market. When demand for a commodity decreases, generally the price falls. Normally, this would cause profits to fall and, as a consequence, the least efficient firms may be forced from the industry. Demand changes for specific materials as final goods or production techniques are reengineered while maintaining or improving product performance, for example, the use of aluminum in the place of copper in long distance electrical transmission lines or plastic replacing steel in automobile bumpers. Substitution contributes to efficient material usage by utilizing cheaper or technically superior materials. In this way, it may also alleviate materials scarcity. If a material becomes relatively scarce (and thus more expensive), a more abundant (and less expensive) material generally replaces it (Wagner and others, 2003, p. 91).

Open-File Report↗
USGS2011

Guidance manual for forensic analysis of perchlorate in groundwater using chlorine and oxygen isotopic analyses

Increased health concerns about perchlorate (ClO4-) during the past decade and subsequent regulatory considerations have generated appreciable interest in source identification. The key objective of the isotopic techniques described in this guidance manual is to provide evidence concerning the origin of ClO4- in soils and groundwater and, more specifically, whether that ClO4- is synthetic or natural. Chlorine and oxygen isotopic analyses of ClO4- provide the primary direct approach whereby different sources of ClO4- can be distinguished from each other. These techniques measure the relative abundances of the stable isotopes of chlorine (37Cl and 35Cl) and oxygen (18O, 17O, and 16O) in ClO4- using isotope-ratio mass spectrometry (IRMS). In addition, the relative abundance of the radioactive chlorine isotope 36Cl is measured using accelerator mass spectrometry (AMS). Taken together, these measurements provide four independent quantities that can be used to distinguish natural and synthetic ClO4- sources, to discriminate different types of natural ClO4-, and to detect ClO4- biodegradation in the environment. Other isotopic, chemical, and geochemical techniques that can be applied in conjunction with isotopic analyses of ClO4- to provide supporting data in forensic studies are also described. This guidance manual is intended to provide details of the methodology used to (1) collect ClO4- samples from the environment, particularly from groundwater, which is the main medium of interest for ClO4- source identification; (2) purify the collected ClO4- samples; (3) conduct oxygen (O) and chlorine (Cl) isotopic analyses on the purified samples; and (4) determine probable sources using the resulting isotope data. Current practices for groundwater sampling and quality assurance for sample collection, purification, and measurement of Cl and O isotopes in ClO4- are provided. A detailed case study of source evaluation in groundwater on Long Island is given along with the current literature on the subject of ClO4- source discrimination. ClO4- in the environment is derived from both synthetic and natural sources. Synthetic ClO4- salts, including ammonium perchlorate (NH4ClO4) and potassium perchlorate (KClO4), have been widely used as oxidants by the military and aerospace industry. A variety of commercial products also contain synthetic ClO4-,including fireworks, matches, air bags, chlorine bleach, safety flares, perchloric acid, and chlorate herbicides. Historical disposal practices by the military, aerospace industry, and chemical manufacturers have resulted in groundwater and drinking water contamination with ClO4- in the United States. Isolated contamination from fireworks, road flares, explosives, and perchloric acid has also been reported. However, ClO4- is also a naturally occurring anion. It is present with sodium nitrate (NaNO3) in surficial deposits in the Atacama Desert of Chile at an average concentration of around 0.1% (by mass) of the total soluble salt, and these deposits (sometimes referred to as “Chilean caliche”) were widely used in the United States during the first half of the 20th century as a source of inorganic nitrogen fertilizer. Natural ClO4- that is not associated with Chilean fertilizers has also recently been detected in the vadose zone, groundwaters, and mineral deposits collected from the arid southwestern United States, including 155,000 km2 of groundwater in the Southern High Plains (SHP) of Texas and New Mexico. In addition to synthetic sources, natural ClO4- from both Chilean fertilizers and indigenous sources represents a potentially large source of ClO4- in groundwater and drinking water in the United States.

Report↗
USGS1979

A geohydrologic overview for the Pecora Symposium field trip, June 1979

The settlement and development of South Dakota has been closely related to both its mineral and water resources In 1874 the discovery of gold in the Black Hills led to the opening and development of the area west of the Missouri River. Towns and farms both here and east of the Missouri were located near dependable water supplies which the settlers learned were not as plentiful as in the more humid areas in the east. Although there is still much dry-land farming and cattle raising throughout the State, the expansion of agriculture has depended heavily on the development of controlled water supplies. Water from flowing artesian wells was extremely important to early settlers and developers. Today, thousands of these wells still supply an important part of the water on which South Dakota's agricultural, tourist, and industrial economy thrive.

South Dakota↗
USGS2025

Modeling interconnected minerals markets with multicommodity supply curves: Examining the copper-cobalt-nickel system

Demand for many of the metals used in the energy transition is expected to grow rapidly. Many of these are by-products, often considered critical because their production responds weakly to prices and is instead tied to the economics of the host mineral. We present a model of prices and production for jointly produced commodities that accounts for interconnectivity between host and by-product markets at the mine level. We demonstrate this method using the copper–cobalt–nickel system, in which approximately 99% of cobalt is a by-product of copper or nickel mining. Our results show that the model more accurately captures the economic benefits of diversified mine outputs than previous approaches. Furthermore, changes in demand drivers for any two commodities produce non-linear effects on production and price. We challenge the prior best-practice assumption that cobalt cannot impact the copper or nickel markets. Recognizing the importance of both copper and cobalt for future electrification, we emphasize that incentivizing the copper industry to reduce cobalt supply risks could inadvertently undermine copper supply.

Nature Communications↗
USGS2012

Deepwater Program: Studies of Gulf of Mexico lower continental slope communities related to chemosynthetic and hard substrate habitats

This report summarizes research funded by the U.S. Geological Survey (USGS) in collaboration with the University of North Carolina at Wilmington (UNCW) on the ecology of deep chemosynthetic communities in the Gulf of Mexico. The research was conducted at the request of the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE; formerly Minerals Management Service) to complement a BOEMRE-funded project titled "Deepwater Program: Investigations of Chemosynthetic Communities on the Lower Continental Slope of the Gulf of Mexico." The overall research partnership, known as "Chemo III," was initiated to increase understanding of the distribution, structure, function, and vulnerabilities of these poorly known associations of animals and microbes for water depths greater than 1,000 meters (m) in the Gulf of Mexico. Chemosynthetic communities rely on carbon sources that are largely independent of sunlight and photosynthetic food webs. Despite recent research directed toward chemosynthetic and deep coral (for example, Lophelia pertusa) based ecosystems, these habitats are still poorly studied, especially at depths greater than 1,000 m. With the progression into deeper waters by fishing and energy industries, developing sufficient knowledge to manage these deep ecosystems is essential. Increased understanding of deep-sea communities will enable sound evaluations of potential impacts and appropriate mitigations.

Gulf Of Mexico↗
USGS2008

Inventory and review of existing PRISM hydrogeologic data for the Islamic Republic of Mauritania, Africa

The USGS entered into an agreement with the Mauritania Ministry of Mines and Industry to inventory and review the quality of information collected as part of the Project for Strengthening of the Institutions in the Mining Sector (PRISM). Whereas the PRISM program collected geophysical, geochemical, geological, satellite, and hydrogeologic information, this report focuses on an inventory and review of available hydrogeologic data provided to the USGS in multiple folders, files, and formats. Most of the information pertained to the hydrogeologic setting and the water budget of evaporation, evapotranspiration, and precipitation in the Choum-Zouerate area in northwestern Mauritania, and the country of Mauritania itself. Other information about the quantity and quality of groundwater was found in the relational Access database. In its present form, the limited hydrogeologic information was not amenable to conducting water balance, geostatistical, and localized numerical modeling studies in support of mineral exploration and development. Suggestions are provided to remedy many of the data's shortcomings, such as performing quality assurance on all SIPPE2 data tables and sending questionnaires to appropriate agencies, mining and other companies to populate the database with additional meteorology, hydrology, and groundwater data.

Open-File Report↗
USGS2012

Alluvial diamond resource potential and production capacity assessment of Guinea

In May of 2000, a meeting was convened in Kimberley, South Africa, by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that export shipments of rough diamonds were free of conflict concerns. Outcomes of the meeting were formally supported later in December of 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by diamond-producing and diamond-importing countries. The goal of this study was to estimate the alluvial diamond resource endowment and the current production capacity of the alluvial diamond mining sector of Guinea. A modified volume and grade methodology was used to estimate the remaining diamond reserves within Guinea's diamondiferous regions, while the diamond-production capacity of these zones was estimated by inputting the number of artisanal miners, the number of days artisans work per year, and the average grade of the deposits into a formulaic expression. Guinea's resource potential was estimated to be approximately 40 million carats, while the production capacity was estimated to lie within a range of 480,000 to 720,000 carats per year. While preliminary results have been produced by integrating historical documents, five fieldwork campaigns, and remote sensing and GIS analysis, significant data gaps remain. The artisanal mining sector is dynamic and is affected by a variety of internal and external factors. Estimates of the number of artisans and deposit variables, such as grade, vary from site to site and from zone to zone. This report has been developed on the basis of the most detailed information available at this time. However, continued fieldwork and evaluation of artisanally mined deposits would increase the accuracy of the results.

Scientific Investigations Report↗
USGS2015

Indium: bringing liquid-crystal displays into focus

Introduction Indium is rare in the Earth’s crust. The continental crust contains an average of about 50 parts per billion of indium, whereas the oceanic crust contains about 72 parts per billion, which is similar to meteoritic abundances and comparable to the crustal abundance of silver. Indium minerals are rare in nature and only 12 indium minerals are known. In its elemental form, indium is a soft, lustrous, silver-white metal with a low melting point relative to other metals. It is ductile and malleable, even at temperatures approaching absolute zero, making it ideal for cryogenic applications. Indium was discovered in the mid-1800s by two German chemists who were investigating zinc ores from Freiberg, Saxony. They named it after the distinctive indigo-blue color observed in its emission spectrum. For years indium remained only a scientific curiosity and early applications of indium were few, but included manufacturing of light-emitting diodes and coatings for bearings used in aircraft engines. Indium-bearing nuclear control rods became more widely used in the 1970s, and today the major application of indium is in manufacturing liquid-crystal displays. Compared to more abundant industrial metals such as lead and zinc, information about the behavior and toxicity of indium in the environment is limited. However, many indium compounds have been proven to be toxic to animals.

Fact Sheet↗
USGS2008

Scientific objectives of the Gulf of Mexico gas hydrate JIP leg II drilling

The Gulf of Mexico Methane Hydrate Joint Industry Project (JIP) has been performing research on marine gas hydrates since 2001 and is sponsored by both the JIP members and the U.S. Department of Energy. In 2005, the JIP drilled the Atwater Valley and Keathley Canyon exploration blocks in the Gulf of Mexico to acquire downhole logs and recover cores in silt- and clay-dominated sediments interpreted to contain gas hydrate based on analysis of existing 3-D seismic data prior to drilling. The new 2007-2009 phase of logging and coring, which is described in this paper, will concentrate on gas hydrate-bearing sands in the Alaminos Canyon, Green Canyon, and Walker Ridge protraction areas. Locations were selected to target higher permeability, coarser-grained lithologies (e.g., sands) that have the potential for hosting high saturations of gas hydrate and to assist the U.S. Minerals Management Service with its assessment of gas hydrate resources in the Gulf of Mexico. This paper discusses the scientific objectives for drilling during the upcoming campaign and presents the results from analyzing existing seismic and well log data as part of the site selection process. Alaminos Canyon 818 has the most complete data set of the selected blocks, with both seismic data and comprehensive downhole log data consistent with the occurrence of gas hydrate-bearing sands. Preliminary analyses suggest that the Frio sandstone just above the base of the gas hydrate stability zone may have up to 80% of the available sediment pore space occupied by gas hydrate. The proposed sites in the Green Canyon and Walker Ridge areas are also interpreted to have gas hydrate-bearing sands near the base of the gas hydrate stability zone, but the choice of specific drill sites is not yet complete. The Green Canyon site coincides with a 4-way closure within a Pleistocene sand unit in an area of strong gas flux just south of the Sigsbee Escarpment. The Walker Ridge site is characterized by a sand-prone sedimentary section that rises stratigraphically across the base of the gas hydrate stability zone and that has seismic indicators of gas hydrate.

Conference Paper↗
USGS1967

Geology and petrology of the Greenville quadrangle, Piscataquis and Somerset Counties, Maine

In the Greenville quadrangle, west-central Maine, slate, siltstone, and sandstone (calcareous and noncalcareous) of probable Silurian to Early Devonian age are intruded by a large mafic pluton and two granitic stocks of probable Early Devonian age. Ages of the sedimentary rocks are based upon tentative correlations with fossiliferous beds in adjacent quadrangles because the few fossils in the Greenville quadrangle are nondiagnostic; ages of the intrusive rocks are based upon radiometric age determinations. The sedimentary rocks are tightly folded about northeast-trending axes and have strong slaty cleavage. Widespread graded bedding is very useful in determining the tops of beds and thus the location of fold axes. The sedimentary rocks are in the chlorite zone of metamorphism except in the contact aureoles where the metamorphism ranges from the biotite zone, through the andalusiite-amphibole zone, to the sillimanite-cordierite zone adjacent to the intrusions; retrograde metamorphism is a minor local feature. The mafic rocks are part of the Moxie pluton, which extends southwest and northeast of the Greenville quadrangle for a total distance of about 45 miles. Troctolite and norite are the principal rock types; gabbro is less common. Plagioclase is the dominant mineral; it usually makes up 50-75 percent of the rock. Olivine and orthopyroxene are widespread, clinopyroxene is uncommon and biotite and hornblende are generally present in small amounts. The rocks can be separated into magnesium-rich and iron-rich varieties; magnesium-rich olivine and orthopyroxene are usually accompanied by plagioclase containing from 57 to 77 percent anorthite, and iron-rich olivine and orthopyroxene are associated with plagioclase containing about 50-62 percent anorithite. Compositional layering is rare, but flow structure is very common. Flow structure generally dips northward to eastward, whereas geophysical data indicate that the contacts of the pluton dip southeastward. The granitic stocks are discordant pipelike bodies that range from granodiorite to quartz monzonite in composition. Both the mafic and the felsic intrusions are undeformed and unmetamorphosed. Slate quarrying was once an important industry in the region, but in 1965 only one quarry was active at Monson just east of the report area. Slate is a potential source of raw material for lightweight concrete aggregate. There are several possible sites for stone quarries in the intrusive masses. Sand and gravel resources seem to be limited. Small amounts of sulfides that have low copper and nickel values are known at a few places in the mafic pluton.

Maine↗
USGS1976

Availability and chemical characteristics of ground water in central La Plata County, Colorado

The central part of La Plata County, Colo., has undergone rapid population growth in recent years. This growth has resulted in an increased demand for information for additional domestic, industrial, and municipal water supplies. A knowledge of the occurrence of ground water will permit a more efficient allocation of the resource. Aquifers in central La Plata County include: alluvium, Animas Formation of Quaternary and Tertiary age, Fruitland Formation, Pictured Cliffs Sandstone, three formations of the Mesa Verde Group, the Mancos Shale, Dakota Sandstone, Morrison Formation of Cretaceous and Jurassic age, and undifferentiated formations. Well yields generally are low, usually less than 25 gallons per minute. However, higher yields, 25 to 50 gallons per minute may be found locally in aquifers in the alluvium and the Animas Formation. The quality of water from the aquifers is dependent on rock type. Most of the water is a calcium bicarbonate type. However, aquifers that are predominantly fine-grained or contain interbeds of shale may contain sodium bicarbonate type water. The dissolution of minerals in the coal beds, which are present in the Mesa Verde Group and the Dakota Sandstone, can contribute high concentrations of iron, sulfate, and chloride to ground water. (Woodard-USGS)

Water-Resources Investigations Report↗
USGS2014

Composition of dust deposited to snow cover in the Wasatch Range (Utah, USA): Controls on radiative properties of snow cover and comparison to some dust-source sediments

Dust layers deposited to snow cover of the Wasatch Range (northern Utah) in 2009 and 2010 provide rare samples to determine the relations between their compositions and radiative properties. These studies are required to comprehend and model how such dust-on-snow (DOS) layers affect rates of snow melt through changes in the albedo of snow surfaces. We evaluated several constituents as potential contributors to the absorption of solar radiation indicated by values of absolute reflectance determined from bi-conical reflectance spectroscopy. Ferric oxide minerals and carbonaceous matter appear to be the primary influences on lowering snow-cover albedo. Techniques of reflectance and Mössbauer spectroscopy as well as rock magnetism provide information about the types, amounts, and grain sizes of ferric oxide minerals. Relatively high amounts of ferric oxide, indicated by hard isothermal remanent magnetization (HIRM), are associated with relatively low average reflectance (<0.25) across the visible wavelengths of the electromagnetic spectrum. Mössbauer spectroscopy indicates roughly equal amounts of hematite and goethite, representing about 35% of the total Fe-bearing phases. Nevertheless, goethite (α-FeOOH) is the dominant ferric oxide found by reflectance spectroscopy and thus appears to be the main iron oxide control on absorption of solar radiation. At least some goethite occurs as nano-phase grain coatings less than about 50 nm thick. Relatively high amounts of organic carbon, indicating as much as about 10% organic matter, are also associated with lower reflectance values. The organic matter, although not fully characterized by type, correlates strongly with metals (e.g., Cu, Pb, As, Cd, Mo, Zn) derived from distal urban and industrial settings, probably including mining and smelting sites. This relation suggests anthropogenic sources for at least some of the carbonaceous matter, such as emissions from transportation and industrial activities. The composition of the DOS samples can be compared with sediments in a likely dust-source setting at the Milford Flat Fire (MFF) area about 225 km southwest of Salt Lake City. The MFF area represents geologically and physiographically similar and widespread dust sources west-southwest of the Wasatch Range and heavily populated Wasatch Front. The DOS layers and MFF sediments are similar in some textural, chemical, and magnetic properties, as well as in the common presence of goethite, hematite, magnetite-bearing basalt fragments, quartz, plagioclase, illite, and kaolinite. Textural and some chemical differences among these deposits can be explained by atmospheric sorting as well as by inputs from other settings, such as salt-crusted playas and contaminant sources.

Utah↗
USGS1981

Water resources inventory of Connecticut Part 7: upper Connecticut River basin

The 508 square miles of the upper Connecticut River basin in north-central Connecticut include the basins of four major tributaries: the Scantic, Park, and Hockanum Rivers, and the Farmington River downstream from Tariffville. Precipitation over this area averaged 44 inches per year during 1931-60. In this period, an additional 3,800 billion gallons of water per year entered the basin in the main stem of the Connecticut River at the Massachusetts state line, about 230 billion gallons per year in the Farmington River at Tariffville, and about 10 billion gallons per year in the Seantic River at the Massachusetts state line. Some water was also imported from outside the basin by water-supply systems. About half the precipitation, 22.2 inches, was lost from the basin by evapotranspiration; the remainder flowed out of the study area in the Connecticut River at Portland. Variations in streamflow at 41 long-term continuous-record gaging stations are summarized in standardized graphs and tables that can be used to estimate streamflow characteristics at other sites. For example, mean-flow and two low-flow characteristics: (1) the 7-day annual minimum flow for 2-year and (2) 10-year recurrence intervals, have been determined for many partial-record stations throughout the basin. Of the 30 principal lakes, ponds, and reservoirs, two have usable storage capacities of more than 1 billion gallons. The maximum safe draft rate (regulated flow) of the largest of these, Shenipsit Lake at Rockville, is 6.5 million gallons per day for the 2-year and 30-year recurrence intervals (median and lowest annual flow). Floods have occurred within each month of the year but in different years. The greatest known flood on the Connecticut River was in March 1936; it had a peak flow of 130,000 cubic feet per second at Hartford. Since then, major floods have been reduced by flood-control measures. The major aquifers underlying the basin are composed of unconsolidated materials (stratified drift and till) and bedrock. Stratified drift overlies till and bedrock in valleys and lowlands in the eastern and western parts and in most of the broad central valley. The stratified drift generally ranges in thickness from 10 feet in small valleys to more than 200 feet in the Connecticut River Valley. Bedrock underlies the entire basin and is composed of (1) interbedded sedimentary and igneous rocks and (2) crystalline rocks. Ground-water sources yield from several million gallons per day from large well fields to 1 gallon per minute from single wells. Yields of 100 gal/min or more are most commonly obtained from screened wells tapping stratified-drift aquifers; amounts can be calculated by use of a series of graphs in conjunction with estimates of aquifer transmissivity and thickness. Eighteen areas underlain by good aquifers are selected as the most favorable locations for large-scale development of ground water. Selection of these areas is based on estimates of aquifer characteristics and the amount of water potentially available from induced infiltration of streamflow at low-flow conditions. Small to moderate water supplies can generally be obtained from any of the aquifers. Wells in bedrock yield at least a few gallons per minute at most sites. The probability of obtaining an adequate yield for domestic supply is greater in sedimentary than in crystalline bedrock and is also greater in stratified-drift overburden than in till. Where unaffected by man's activities, the water is of the calcium magnesium bicarbonate type, is generally low to moderate in dissolved-solids concentration, and ranges from soft to hard. In general, streamflow is less mineralized than ground water, particularly when it consists largely of direct runoff. However, streams become more highly mineralized during low-flow conditions, when most flow consists of more highly mineralized water discharged from aquifers. The median dissolved-solids concentration in water from 25 stream sites was 113 mg/L (milligrams per liter) during high flow, and 148 mg/L during low flow within the study period. Iron and manganese occur naturally in objectionable concentrations in some streams draining swamps and in some waters draining from sedimentary bedrock which contains iron- and manganese-bearing minerals. Man's activities have affected the water quality of streams in much of the area, particularly in the Hockanum and Park River basins. The degradation in quality in these streams is shown by wide and erratic changes in dissolved-solids concentration, excessive amounts of trace elements, a low dissolved-oxygen content, and abnormally high temperatures. Ground water within this area is degraded principally by induced infiltration of surface water that contains chemical wastes, by leachate from wastes stored or disposed of on the ground, and by effluents discharged from septic tanks. The quantity and quality of water are satisfactory for a wide variety of uses, and, with suitable treatment, the water may be used for most purposes. The total amount of water used in 1968 was more than 100 billion gallons. About 80 percent of this was used for industrial purposes, and 90 percent of the industrial water was obtained from surface-water sources. About 85 percent of the population was supplied with water for domestic use by 15 major public and municipal systems and 25 private associations. Analyses of water from the 13 largest systems show generally good quality.

Connecticut↗
USGS2016

Pb-Sr isotopic and geochemical constraints on sources and processes of lead contamination in well waters and soil from former fruit orchards, Pennsylvania, USA: A legacy of anthropogenic activities

Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site, near Allentown, PA, were evaluated to discern anthropogenic from geogenic sources. Pb (n = 144) and Sr (n = 40) isotopic data and REE (n = 29) data were determined for waters from residential wells, test wells (drilled for this study), and surface waters from pond and creeks. Local soils, sediments, bedrock, Zn-Pb mineralization and coal were also analyzed (n = 94), together with locally used Pb-As pesticide (n = 5). Waters from residential and test wells show overlapping values of 206 Pb/ 207 Pb, 208 Pb/ 207 Pb and 87 Sr/ 86 Sr. Larger negative Ce anomalies (Ce/Ce*) distinguish residential wells from test wells. Results show that residential and test well waters, sediments from residential water filters in water tanks, and surface waters display broad linear trends in Pb isotope plots. Pb isotope data for soils, bedrock, and pesticides have contrasting ranges and overlapping trends. Contributions of Pb from soils to residential well waters are limited and implicated primarily in wells having shallow water-bearing zones and carrying high sediment contents. Pb isotope data for residential wells, test wells, and surface waters show substantial overlap with Pb data reflecting anthropogenic actions (e.g., burning fossil fuels, industrial and urban processing activities). Limited contributions of Pb from bedrock, soils, and pesticides are evident. High Pb concentrations in the residential waters are likely related to sediment build up in residential water tanks. Redox reactions, triggered by influx of groundwater via wells into the residential water systems and leading to subtle changes in pH, are implicated in precipitation of Fe oxyhydroxides, oxidative scavenging of Ce(IV), and desorption and release of Pb into the residential water systems. The Pb isotope features in the residences and the region are best interpreted as reflecting a legacy of industrial Pb present in underlying aquifers that currently supply the drinking water wells.

Pennsylvania↗
USGS1986

Water resources inventory of Connecticut Part 9: Farmington River basin

The Farmington River basin covers 435 square miles in north-central Connecticut upstream from Tariffville and downstream of the Massachusetts state line. Most water in the basin is derived from precipitation, which averages 48 inches (366 billion gallons) per year. An additional 67 billion gallons of water per year enters the basin from Massachusetts in the West Branch of the Farmington River, Hubbard River, Valley Brook and some smaller streams. Of the total 433 billion gallons, 174 billion gallons returns to the atmosphere through evaporation and transpiration. 239 billion gallons flows out of the study area in the Farmington River at Tariffville, and 20 billion gallons is diverted for Hartford water supply. Variations in streamflow at 23 continuous-record gaging stations are summarized in standardized graphs and tables that can be used to estimate streamflow characteristics at other sites. For example, mean flow and low-flow characteristics such as the 7-day annual minimum flow for 2-year and 10-year recurrence intervals, have been determined for many partial-record stations from the data for the 23 continuous-record stations. Of the 31 principal lakes, ponds, and reservoirs in the basin, eight have usable storage capacities of more than 1 billion gallons. Two of the largest, Colebrook River Lake and Barkhamsted Reservoir, have more than 30 billion gallons usable storage. Floods have occurred in the area in every month of the year. The greatest known flood on the Farmington River was in August 1955, which had a peak flow of 140,000 cubic feet per second at Collinsville. Since then, three major floodcontrol reservoirs have been constructed to reduce the hazards of high streamflow. The major aquifers underlying the basin are composed of unconsolidated materials (stratified drift and till) and bedrock (sedimentary, igneous, and metamorphic). Stratified drift overlies till and bedrock in valleys and lowlands; it averages about 90 feet in thickness, and is capable of large sustained yields of water to individual wells. Based on hydrologic characteristics and available recharge, sixteen stratified-drift areas are selected as the most favorable for large-scale development. Potential yields can be estimated by several methods. Small water supplies can be obtained from all aquifers. Wells in bedrock yield at least one to two gallons per minute at most sites. The probability of adequate yields for domestic supply is greater from sedimentary than from crystalline bedrock and is also greater from stratified-drift overburden than from till. The quality of water from all sources in the basin is good except where adversely affected by swamp drainage, aquifer composition or human activities. The water is generally low in dissolved-solids concentration and is soft to moderately hard. Surface water is less mineralized than ground water, especially during high-flow conditions when it is primarily direct runoff. Samples of water collected from 20 streams during high flow had 34 mg/L median dissolved-solids concentration and 16 mg/L median hardness. Samples collected from the same sites at low flow had 52 mg/L median dissolved solids and 28 mg/L median hardness. In contrast, water from wells had 112 mg/L median dissolved-solids concentration and 60 mg/L median hardness. Iron and manganese occur in objectionable concentrations ~n a few parts of the basin where streams drain swamps and aquifers are rich in iron- and manganese-bearing minerals. Five percent of streams at high flow, 21 percent at low flow, and 7 percent of ground-water samples contained iron in sufficient concentration to cause stains on plumbing fixtures and laundry. Human activities have modified the quality of water in parts of the basin. The high bacterial content of the Pequabuck River. and the high nitrate and chloride concentrations in some ground-water samples, are evidence of man&rsquo;s influence. The quantity and quality of water in the basin&rsquo;s streams and aquifers are satisfactory for a wide variety of uses. and, with suitable treatment, may be used for most purposes. The total amount of water used by 21 principal public supplies within the basin was 29 billion gallons in 1970. About 70 percent of this was used for domestic and commercial purposes, and nearly 30 percent was used by industry. Analyses of water from these systems show good quality.

Connecticut↗
USGS1974

Stratigraphy and nahcolite resources of the saline facies of the Green River Formation, Rio Blanco County, Colorado

Based on a study of 10 drill cores, a sequence of oil shale and associated nahcolite, nearly 2,000 feet thick, in the lacustrine Green River Formation (Eocene) in the Piceance Creek basin, Rio Blanco County, Colo., was divided in ascending order into zones 1 to 13, B-groove, Mahogany zone (with lower, middle, and upper parts), and A-groove at the top. The odd-numbered zones and the Mahogany zone are mappable subsurface units of relatively thick oil shale and are distinguished from the even-numbered zones and A- and B-grooves which are thinner units of oil shale of lower grade. Large amounts of nahcolite found in zones 5 to 12 occur in (1) coarse-grained crystalline aggregates scattered through oil shale, (2) laterally continuous units of fine-grained crystals disseminated in oil shale, (3) brown microcrystalline beds, and (4) white coarse-grained beds that grade laterally into halitic rocks toward basin center. The original .upper limit of the nahcolite and halitic rocks is not yet completely known, but the present top is marked by a dissolution surface. Above this surface the rocks, extending from zones 11 or 12 upward into the Mahogany zone, form a water-saturated 'leached zone,' a geohydrologic unit in which large amounts of water-soluble minerals probably mostly nahcolite, and halite, were removed by ground-water dissolution. Rocks in the leached zone, mostly oil shale, are commonly broken and fractured and contain crystal cavities and solution breccias. Several solution breccias can be traced laterally into unleached beds of nahcolite and halite. Although evidence of salines is found in rocks above A-groove, the original saline facies that includes most of the bedded deposits extends from zone 5 upward into A-groove. Potentially ruinable beds of white nahcolite as much as 12 feet thick are found at depths of 1,560 or more feet below the surface. Some thicker beds of high-grade nahcolite are believed to be too close to the dissolution surface for safe room-and-pillar mining. Probably the most economical method of mining nahcolite would be as a coproduct of a shale-oil industry. Removal of nahcolite prior to retorting increases significantly the grade of oil shale by as much as 1.6 times, Several zones are more than 300 feet thick and average 30 or more weight percent nahcolite. Resources of nahcolite per square mile range as high as 489 million short tons. The total nahcolite resource in the basin is conservatively estimated at 32 billion short tons, which makes it the secondlargest deposit of sodium carbonate known .in the world.

Open-File Report↗
USGS1964

Geology and ground-water resources of Richardson County, Nebraska

Richardson County is in the extreme southeast corner of Nebraska. It has an area of 545 square miles, and in 1960 it had a population of 13,903. The county is in the physiographic region referred to as the Dissected Loess-covered Till Prairies. Major drainage consists of the Big Nemaha River, including its North and South Forks, and Muddy Creek. These streams flow southeastward and empty into the Missouri River, which forms the eastern boundary of the county. The climate of Richardson County is subhumid; the normal annual precipitation is about 35 inches. Agriculture is the chief industry, and corn is the principal crop. Pleistocene glacial drift, loess, and alluvial deposits mantle the bedrock except in the southern and southwestern parts of the county where the bedrock is at the surface. Ground water is obtained from glacial till, fluvioglacial material, terrace deposits, and coarse alluvial deposits, all of Pleistocene age--and some is obtained from bedrock aquifers of Pennsylvanian and Permian age. Adequate supplies of ground water are in many places difficult to locate because the water-bearing sands and gravels of Pleistocene age vary in composition and lack lateral persistence. Perched water tables are common in the upland areas and provide limited amounts of water to many of the shallow wells, Very few wells in bedrock yield adequate supplies, as the permeability of the rock is low and water that is more than a few tens of feet below the bedrock surface is highly mineralized. Recharge is primarily from local precipitation, and water levels in many wells respond rapidly to increased or decreased precipitation. The quality of the ground water is generally satisfactory for most uses, although all the water is hard, and iron and manganese concentrations, in some areas, are relatively high. Ground water is used mainly for domestic and stock purposes.

Water Supply Paper↗