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At least 865 records · Page 48Linked to original sources

Investigation of water quality and aquatic-community structure in Village and Valley Creeks, City of Birmingham, Jefferson County, Alabama, 2000-01

The U.S. Geological Survey conducted a 16-month investigation of water quality, aquatic-community structure, bed sediment, and fish tissue in Village and Valley Creeks, two urban streams that drain areas of highly intensive residential, commercial, and industrial land use in Birmingham, Alabama. Water-quality data were collected between February 2000 and March 2001 at four sites on Village Creek, three sites on Valley Creek, and at two reference sites near Birmingham?Fivemile Creek and Little Cahaba River, both of which drain less-urbanized areas. Stream samples were analyzed for major ions, nutrients, fecal bacteria, trace and major elements, pesticides, and selected organic constituents. Bed-sediment and fish-tissue samples were analyzed for trace and major elements, pesticides, polychlorinated biphenyls, and additional organic compounds. Aquatic-community structure was evaluated by conducting one survey of the fish community and in-stream habitat and two surveys of the benthic-invertebrate community. Bed-sediment and fish-tissue samples, benthic-invertebrates, and habitat data were collected between June 2000 and October 2000 at six of the nine water-quality sites; fish communities were evaluated in April and May 2001 at the six sites where habitat and benthic-invertebrate data were collected. The occurrence and distribution of chemical constituents in the water column and bed sediment provided an initial assessment of water quality in the streams. The structure of the aquatic communities, the physical condition of the fish, and the chemical analyses of fish tissue provided an indication of the cumulative effects of water quality on the aquatic biota. Water chemistry was similar at all sites, characterized by strong calcium-bicarbonate component and magnesium components. Median concentrations of total nitrogen and total phosphorus were highest at the headwaters of Valley Creek and lowest at the reference site on Fivemile Creek. In Village Creek, median concentrations of nitrite and ammonia increased in a downstream direction. In Valley Creek, median concentrations of nitrate, nitrite, ammonia, organic nitrogen, suspended phosphorus, and orthophosphate decreased in a downstream direction. Median concentrations of Escherichia coli and fecal coliform bacteria were highest at the most upstream site of Valley Creek and lowest at the reference site on Fivemile Creek. Concentrations of enterococci exceeded the U.S. Environmental Protection Agency criterion in 80 percent of the samples; concentrations of Escherichia coli exceeded the criterion in 56 percent of the samples. Concentrations of bacteria at the downstream sites on Village and Valley Creeks were elevated during high flow rather than low flow, indicating the presence of nonpoint sources. Surface-water samples were analyzed for chemical compounds that are commonly found in wastewater and urban runoff. The median number of wastewater indicators was highest at the most upstream site on Valley Creek and lowest at the reference site on Fivemile Creek. Concentrations of total recoverable cadmium, copper, lead, and zinc in surface water exceeded acute and chronic aquatic life criteria in up to 24 percent of the samples that were analyzed for trace and major elements. High concentrations of trace and major elements in the water column were detected most frequently during high flow, indicating the presence of nonpoint sources. Of the 24 pesticides detected in surface water, 17 were herbicides and 7 were insecticides. Atrazine, simazine, and prometon were the most commonly detected herbicides; diazinon, chlorpyrifos, and carbaryl were the most commonly detected insecticides. Concentrations of atrazine, carbaryl, chlorpyrifos, diazinon, and malathion periodically exceeded criteria for the protection of aquatic life. Trace-element priority pollutants, pesticides, and other organic compounds were detected in higher concentrations in bed sediment at the Village and Valley Creek sites t

Water-Resources Investigations Report↗

Characterization of calcium isotopes in natural and synthetic barite

The mineral barite (BaSO4) accommodates calcium in its crystal lattice, providing an archive of Ca-isotopes in the highly stable sulfate mineral. Holocene marine (pelagic) barite samples from the major ocean basins are isotopically indistinguishable from each other (??44/40Ca = -2.01 ?? 0.15???) but are different from hydrothermal and cold seep barite samples (??44/40Ca = -4.13 to -2.72???). Laboratory precipitated (synthetic) barite samples are more depleted in the heavy Ca-isotopes than pelagic marine barite and span a range of Ca-isotope compositions, ??44/40Ca = -3.42 to -2.40???. Temperature, saturation state, a Ba2 + / a SO42 -, and aCa2+/aBa2+ each influence the fractionation of Ca-isotopes in synthetic barite; however, the fractionation in marine barite samples is not strongly related to any measured environmental parameter. First-principles lattice dynamical modeling predicts that at equilibrium Ca-substituted barite will have much lower 44Ca/40Ca than calcite, by -9??? at 0 ??C and -8??? at 25 ??C. Based on this model, none of the measured barite samples appear to be in isotopic equilibrium with their parent solutions, although as predicted they do record lower ??44/40Ca values than seawater and calcite. Kinetic fractionation processes therefore most likely control the extent of isotopic fractionation exhibited in barite. Potential fractionation mechanisms include factors influencing Ca2+ substitution for Ba2+ in barite (e.g. ionic strength and trace element concentration of the solution, competing complexation reactions, precipitation or growth rate, temperature, pressure, and saturation state) as well as nucleation and crystal growth rates. These factors should be considered when investigating controls on isotopic fractionation of Ca2+ and other elements in inorganic and biogenic minerals. ?? 2008 Elsevier Ltd.

Geochimica et Cosmochimica Acta↗

Water-quality characteristics and contaminants in the rural karst-dominated Spring Mill Lake watershed, southern Indiana

The Spring Mill Lake watershed is located in the Mitchell Plateau, a karst area that developed on Mississippian carbonates in southern Indiana. Spring Mill Lake is a reservoir built in the late 1930s and is located in Spring Mill State Park. Within the park, groundwater from subsurface conduits issues as natural springs and then flows in surface streams to the lake. From 1998 to 2002, surface and subsurface hydrology and water quality were investigated to determine the types and sources of potential contaminants entering the lake. Water samples collected during base flow and a February 2000 storm event were analyzed for selected cations, anions, trace elements, selected U.S. Environmental Protection Agency (EPA) primary and secondary drinkingwater contaminants, nitrogen isotopes, suspended solids, Escherichia coli, and pesticides. All of the water samples met the EPA drinking-water standards for inorganic constituents, except those collected at five sites in August 1999 during a drought. Nitrate nitrogen (NO 3 -N) concentrations were highest during base-flow conditions and displayed a dilutional trend during peak-flow periods. The NO 3 -N concentrations in water samples collected during the 2001 spring fertilizer applications tended to increase from early to late spring. All of the ?? 15 N values were low, which is indicative of either an inorganic source or soil organic matter. Storm discharge contained increased concentrations of total suspended solids; thus, storms are responsible for most of the sediment accumulation in the lake. E. coli levels in 24% of the samples analyzed contained a most probable number (MPN) greater than 235/100 mL, which is the maximum acceptable level set for recreational waters in Indiana. E. coli does appear to be a potential health risk, particularly at Rubble spring. The sources of E. coli found at this spring may include barnyard runoff from a horse barn or wastes from a wastewater treatment facility. The pesticides atrazine, metolachlor, acetochlor, and simazine were detected during the spring of 2001. Atrazine, metolachlor, acetochlor, and simazine are used to suppress weeds during corn and soybean production. Additional sources of atrazine and simazine may result from application to right-of-ways, orchards, and managed forest areas. ?? 2006 Geological Society of America.

Special Paper of the Geological Society of America↗

Water-Chemistry and On-Site Sulfur-Speciation Data for Selected Springs in Yellowstone National Park, Wyoming, 1996-1998

Fifty-eight water analyses are reported for samples collected from 19 hot springs and their overflow drainages and one ambient-temperature acid stream in Yellowstone National Park (YNP) during 1996-98. These water samples were collected and analyzed as part of research investigations on microbially mediated sulfur oxidation in stream waters and sulfur redox speciation in hot springs in YNP and chemical changes in overflow drainages that affect major ions, redox species, and trace elements. The research on sulfur redox speciation in hot springs is a collaboration with the State University of New York at Stony Brook, Northern Arizona University, and the U.S. Geological Survey (USGS). One ambient-temperature acidic stream system, Alluvium Creek and its tributaries in Brimstone Basin, was studied in detail. Analyses were performed adjacent to the sampling site, in an on-site mobile laboratory truck, or later in a USGS laboratory, depending on stability and preservability of the constituent. Water temperature, specific conductance, pH, Eh, dissolved oxygen (D.O.), and dissolved H2S were determined on-site at the time of sampling. Alkalinity and F were determined within a few days of sample collection by titration and by ion-selective electrode, respectively. Concentrations of S2O3 and SxO6 were determined as soon as possible (minutes to hours later) by ion chromatography (IC). Concentrations of Cl, SO4, and Br were determined by IC within a few days of sample collection. Concentrations of Fe(II) and Fe(total) were determined by ultraviolet/visible spectrophotometry within a few days of sample collection. Densities were determined later in the USGS laboratory. Concentrations of Li, Na, and K were determined by flame atomic absorption (Li) and emission (Na, K) spectrometry. Concentrations of Al, As(total), B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe(total), Mg, Mn, Ni, Pb, Si, Sr, V, and Zn were determined by inductively-coupled plasma optical emission spectrometry. Trace concentrations of Cd, Se, As(total), Ni, and Pb were determined by Zeeman-corrected graphite-furnace atomic-absorption spectrometry. Trace concentrations of As(total) and As(III) were determined by hydride generation using a flow-injection analysis system.

Open-File Report↗

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas — Surface-water quality, shallow ground-water quality, and factors affecting water quality in the Rincon Valley, south-central New Mexico, 1994-95

As part of the National Water-Quality Assessment Program, surface-water and ground-water samples were collected in 1994 and 1995 for analysis of common constituents, nutrients, dissolved organic carbon, trace elements, radioactivity, volatile organic compounds, and pesticides to characterize surface water quality and shallow ground-water quality and to determine factors affecting water quality in the Rincon Valley, south-central New Mexico. Samples of surface water were collected from three sites on the Rio Grande and from sites on three agricultural drains in the Rincon Valley in January 1994 and 1995, April 1994, and October 1994Ground-water samples were collected in late April and early May 1994 from 30 shallow wells that were installed during the investigation. Dissolved-solids concentrations in surface water ranged from 434 to 1,510 milligrams per liter (mg/L). Dissolved-solids concentrations were smallest in water from the Rio Grande below Caballo Dam and largest in the drains. Nitrite plus nitrate concentrations ranged from less than 0.05 to 3.3 mg/L as nitrogen, and ammonia concentrations ranged from less than 0.015 to 0.33 mg/L as nitrogen in surface-water samples. Trace-element concentrations in surface water were significantly smaller than the acute-fisheries standards. One or more pesticides were detected in 34 of 37 surface-water samples. DCPA (dacthal) and metolachlor were the most commonly detected pesticides. No standards have been established for the pesticides analyzed for in this study. Dissolved-solids concentrations in shallow ground water ranged from 481 to 3,630 mg/L. All but 2 of 30 samples exceeded the secondary maximum contaminant level for dissolved solids of 500 mg/L. Water from about 73 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for sulfate, and water from about 7 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for chloride. Nitrite plus nitrate concentrations ranged from less than 0.05 to 33 mg/L as nitrogen in shallow ground water. Water from about 17 percent of the well samples exceeded the maximum contaminant level of 10 mg/L as nitrogen for nitrite plus nitrate. Trace-element concentrations in shallow ground water generally were small (1 to 10 micrograms per liter)The proposed maximum contaminant level of 20 micrograms per liter for uranium was exceeded in about 13 percent of the samples. The secondary maximum contaminant level of 300 micrograms per liter for iron was exceeded in about 17 percent of the samples and of 50 micrograms per liter for manganese was exceeded in about 83 percent of the samples. Samples from about 23 percent of the wells exceeded the maximum contaminant level of 15 picocuries per liter for gross alpha activity. One or more pesticides were detected in water from 12 of 30 wells sampled. The pesticides or pesticide metabolites diazinon, metolachlor, napropamide, p,p’-DDE, and prometon were detected in one or more samples. Metolachlor and prometon were the most commonly detected pesticides. Health advisories for the pesticides detected in shallow ground water (no maximum contaminant levels have been established for the pesticides detected) are 10 to 300 times larger than the concentrations detected. Infiltration, evaporation, and transpiration of irrigation water are important factors affecting the concentrations of common constituents in shallow ground water in the Rincon Valley. Dissolution and precipitation of minerals and mixing of shallow ground water and inflow of ground water from adjacent areas also affect the composition of shallow ground water and water in the drains. Relatively large nitrite plus nitrate concentrations in several shallow ground-water samples indicate leaching of fertilizers in some areas of the Rincon Valley. Molybdenum and uranium concentrations in part of the Rincon Valley are affected by inflow of ground water to the valley from adjacent areas. A large amount of the gross alpha activity in shallow ground water is from uranium isotopes. Gross beta activity increases with dissolved potassium, indicating that part of the dissolved gross beta activity is from potassium-40. The detection of a larger number of different pesticides in surface water than in ground water indicates that pesticides are entering surface water as runoff from fields or that the number of ground-water samples collected and the time of year that the samples were collected did not adequately represent the composition of ground water in the Rincon Valley that discharges to the drains. On the basis of pesticide concentrations detected in shallow ground water in the Rincon Valley, large amounts of the pesticides analyzed for are not leaching from land surface into ground water. There is some indication that several pesticides are leaching downward into shallow ground water (metolachlor and prometon especially); however, the concentrations detected in shallow ground water are significantly smaller than any standards or health advisories issued by the U.S. Environmental Protection Agency.

New Mexico↗

Sub-glacial volcanic eruptions

The literature on sub-glacial volcanic eruptions and the related flood phenomena has been reviewed as a minor part of the larger problem of convective and conductive heat transfer from intrusive magma. (See Lovering, 1955, for a review of the extensive literature on this subject.) This summary of data on sub-glacial eruptions is part of a program that the U.S. Geological Survey is conducting in connection with its Investigations of Geologic Processes project on behalf of the Division of Research, U.S. Atomic Energy Commission.

Trace Elements Memorandum↗

Geochemistry of southern Pagan Island lavas, Mariana arc: The role of subduction zone processes

New major and trace element abundances, and Pb, Sr, and Nd isotopic ratios of Quaternary lavas from two adjacent volcanoes (South Pagan and the Central Volcanic Region, or CVR) located on Pagan Island allow us to investigate the mantle source (i.e., slab components) and melting dynamics within the Mariana intra-oceanic arc. Geologic mapping reveals a pre-caldera (780-9.4ka) and post-caldera (<9.4ka) eruptive stage for South Pagan, whereas the eruptive history of the older CVR is poorly constrained. Crystal fractionation and magma mixing were important crustal processes for lavas from both volcanoes. Geochemical and isotopic variations indicate that South Pagan and CVR lavas, and lavas from the northern volcano on the island, Mt. Pagan, originated from compositionally distinct parental magmas due to variations in slab contributions (sediment and aqueous fluid) to the mantle wedge and the extent of mantle partial melting. A mixing model based on Pb and Nd isotopic ratios suggests that the average amount of sediment in the source of CVR (~2.1%) and South Pagan (~1.8%) lavas is slightly higher than Mt. Pagan (~1.4%) lavas. These estimates span the range of sediment-poor Guguan (~1.3%) and sediment-rich Agrigan (~2.0%) lavas for the Mariana arc. Melt modeling demonstrates that the saucer-shaped normalized rare earth element (REE) patterns observed in Pagan lavas can arise from partial melting of a mixed source of depleted mantle and enriched sediment, and do not require amphibole interaction or fractionation to depress the middle REE abundances of the lavas. The modeled degree of mantle partial melting for Agrigan (2-5%), Pagan (3-7%), and Guguan (9-15%) lavas correlates with indicators of fluid addition (e.g., Ba/Th). This relationship suggests that the fluid flux to the mantle wedge is the dominant control on the extent of partial melting beneath Mariana arc volcanoes. A decrease in the amount of fluid addition (lower Ba/Th) and extent of melting (higher Sm/Yb), and an increase in the sediment contribution (higher Th/Nb, La/Sm, and Pb isotopic ratios) from Mt. Pagan to South Pagan could reflect systematic cross-arc or irregular along-arc melting variations. These observations indicate that the length scale of compositional heterogeneity in the mantle wedge beneath Mariana arc volcanoes is small (~10km).

Contributions to Mineralogy and Petrology↗

Sediment record of mining legacy and water quality from a drinking-water reservoir, Aztec, New Mexico, USA

The record of mining legacy and water quality was investigated in sediments collected in 2018 from four trenches in the Aztec, New Mexico, drinking-water reservoir #1. Bulk chemical analysis of sediments with depth in the reservoir revealed variable trace-element (uranium, vanadium, arsenic, copper, sulfur, silver, lead, and zinc) concentrations, which appear to coincide with historical mining and milling operations. Cesium-137 age dating, which identified the location of the 1963 radioactive fallout maximum, combined with the known age of the bottom and top of the sediment trenches, was used to estimate a polynomial sedimentation rate (average rate = 1.7 cm/yr). The clay size fraction (< 0.004 mm) was the dominant grain-size fraction of the sediments. Abundant fine-grained phyllosilicate (clay) minerals, predominantly montmorillonite and kaolinite, may explain sorption properties of trace elements. Scanning electron microscopy evaluation of sediments from two trenches showed copper and zinc associated with sulfur, and arsenic associated with iron and aluminum oxides. Results from laboratory batch experiments indicated that uranium, vanadium, and arsenic were released when sediments were reacted with a 150 mg/L sodium bicarbonate solution whereas copper was released when sediments were reacted with 2 mMol/L acetic acid. Observed concentrations from the two leach tests were below regulatory thresholds for delivery of solids to a landfill and were below drinking-water standards. Diatom relative abundance indicates that the water quality in the reservoir was not impaired by high metal concentrations.

Colorado, New Mexico↗

Water-chemistry data for selected springs, geysers, and streams in Yellowstone National Park, Wyoming, 1999-2000

Sixty-seven water analyses are reported for samples collected from 44 hot springs and their overflow drainages and two ambient-temperature acid streams in Yellowstone National Park (YNP) during 1990-2000. Thirty-seven analyses are reported for 1999, 18 for June of 2000, and 12 for September of 2000. These water samples were collected and analyzed as part of research investigations in YNP on microbially mediated sulfur oxidation in stream water, arsenic and sulfur redox speciation in hot springs, and chemical changes in overflow drainages that affect major ions, redox species, and trace elements. Most samples were collected from sources in the Norris Geyser Basin. Two ambient-temperature acidic stream systems, Alluvium and Columbine Creeks and their tributaries in Brimstone Basin, were studied in detail. Analyses were performed at or near the sampling site, in an on-site mobile laboratory truck, or later in a USGS laboratory, depending on stability of the constituent and whether or not it could be preserved effectively. Water temperature, specific conductance, pH, Eh, dissolved oxygen (D.O.), and dissolved H2S were determined on-site at the time of sampling. Alkalinity, acidity, and F were determined within a few days of sample collection by titration with acid, titration with base, and ion-selective electrode or ion chromatography (IC), respectively. Concentrations of S2O3 and SxO6 were determined as soon as possible (minutes to hours later) by IC. Concentrations of Br, Cl, NH4, NO2, NO3, SO4, Fe(II), and Fe(total) were determined within a few days of sample collection. Densities were determined later in the USGS laboratory. Concentrations of Li and K were determined by flame atomic absorption spectrometry. Concentrations of Al, As(total), B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe(total), K, Li, Mg, Mn, Na, Ni, Pb, Se, Si, Sr, V, and Zn were determined by inductively-coupled plasma-optical emission spectrometry. Trace concentrations of Cd, Cr, Cu, Pb, and Sb were determined by Zeeman-corrected graphitefurnace atomic-absorption spectrometry. Trace concentrations of As(total) and As(III) were determined by hydride generation atomic-absorption spectrometry using a flow-injection analysis system. Concentrations of Cl, NO3, Br, and SO4 were determined by IC. Concentrations of Fe(II) and Fe(total) were determined by the ferrozine colorimetric method. Concentrations of NO2 were determined by colorimetry using matrix-matched standards. Concentrations of NH4 were determined by IC, with reanalysis by colorimetry where separation of Na and NH4 peaks was poor. Dissolved organic carbon (DOC) concentrations were determined by the wet persulfate oxidation method.

Wyoming↗

Hydrology and glacier-lake-outburst floods (1987-2004) and water quality (1998-2003) of the Taku River near Juneau, Alaska

The Taku River Basin originates in British Columbia, Canada, and drains an area of 6,600 square miles at the U.S. Geological Survey's Taku River gaging station. Several mines operated within the basin prior to 1957, and mineral exploration has resumed signaling potential for future mining developments. The U.S. Geological Survey in cooperation with the Douglas Indian Association, Alaska Department of Environmental Conservation, and the U.S. Environmental Protection Agency conducted a water-quality and flood-hydrology study of the Taku River. Water-quality sampling of the Taku River from 1998 through 2003 established a baseline for assessing potential effects of future mining operations on water quality. The annual mean discharge of the Taku River is 13,700 cubic feet per second. The monthly mean discharge ranges from a minimum of 1,940 cubic feet per second in February to a maximum of 34,400 cubic feet per second in June. Nearly 90 percent of the annual discharge is from May through November. The highest spring discharges are sourced primarily from snowmelt and moderate discharges are sustained throughout the summer by glacial meltwaters. An ice cover usually forms over the Taku River in December persisting through the winter into March and occasionally into April. Glacier-lake-outburst floods originating from two glacier-dammed lakes along the margin of the Tulsequah Glacier in British Columbia, Canada, are the source of the greatest peak discharges on the Taku River. The largest flood during the period of record was 128,000 cubic feet per second on June 25, 2004, resulting from an outburst of Lake No Lake. Lake No Lake is the larger of the two lakes. The outburst-flood contribution to peak discharge was 80,000 cubic feet per second. The volume discharged from Lake No Lake is relatively consistent indicating drainage may be triggered when the lake reaches a critical stage. This suggests prediction of the timing of these outburst floods might be possible if lake-stage data were available. Further increases in the volume of Lake No Lake are unlikely as all tributary glaciers have retreated out of the lake basin. Decreasing outburst-flood volumes from Tulsequah Lake suggests a continued decline in the volume of this lake. Physical and chemical parameters and concentrations of basic water-quality constituents indicate good water quality. Samples collected at the Taku River gaging station contained low concentrations of trace elements in the dissolved phase. Trace elements sampled were within acceptable limits when compared with the Alaska Department of Environmental Conservation aquatic-life criteria for fresh waters. The highest concentrations of total trace elements sampled were collected during glacial-outburst floods and likely are associated with suspended sediments. Total trace-element concentrations generally increase with increasing water discharge, although a high correlation for all constituents sampled does not always exist.

Alaska↗

Arsenic, chromium, uranium, and vanadium in rock, alluvium, and groundwater, Mojave River and Morongo Areas, western Mojave Desert, southern California

Trace elements within groundwater that originate from aquifer materials and pose potential public-health hazards if consumed are known as geogenic contaminants. The geogenic contaminants arsenic, chromium, and vanadium can form negatively charged ions with oxygen known as oxyanions. Uranium complexes with bicarbonate and carbonate to form negatively charged ions having aqueous chemistry similar to oxyanions. The concentrations of arsenic, chromium, uranium, and vanadium in groundwater result from the combined effects of (1) geologic abundance within aquifer materials; (2) the fraction of these elements that have weathered from and sorbed to the surfaces of mineral grains and are potentially available to groundwater; and (3) the aqueous chemistry of dissolved oxyanions in groundwater during different redox conditions and pH, both of which are affected by hydrogeology, including the length of time groundwater has been in contact with aquifer materials. Concentrations of arsenic, chromium, uranium, and vanadium were measured in samples of (1) rock, surficial alluvium, and drill cuttings using portable (handheld) X-ray fluorescence (pXRF); (2) operationally defined fractions extractable from these materials; and (3) water from wells sampled between 2000 and 2018 within the 3,500 square mile Mojave River area and Morongo area of the western Mojave Desert, southern California. Regionally, rock and surficial alluvium in the Mojave River and Morongo areas are high in arsenic, low in chromium and uranium, and near the average bulk continental crust concentration for vanadium. Locally, high chromium concentrations are present in mafic rock within the San Gabriel Mountains; high uranium concentrations are present in felsic rock within the San Bernardino Mountains; and high arsenic, uranium, and vanadium concentrations are present in extrusive (volcanic) felsic rock within uplands surrounding groundwater basins along the Mojave River downstream from Barstow, California. Elemental assemblages identified using principal component analyses (PCA) of pXRF data were used to characterize felsic, mafic, and felsic volcanic source terranes in rock, surficial alluvium, and in geologic material penetrated by selected monitoring wells drilled between 1994 and 2018. Highly felsic alluvium associated with recent deposition from the Mojave River was identified along the 90-mile length of the floodplain aquifer along the river. The thickness of these highly felsic alluvial deposits ranged from 200 feet (ft) near Victorville and near Barstow to a thin veneer about 30 ft thick downstream from Victorville and downstream portions of the floodplain aquifer within the Mojave Valley. Groundwater in the Mojave River and Morongo areas was generally oxic and alkaline (pH≥7.5). Maximum concentrations of arsenic, hexavalent chromium [Cr(VI)], uranium, and vanadium in water from as many as 498 wells sampled between 2000 and 2018 were 360, 140, 1,470, and 690 micrograms per liter (μg/L), respectively. Water from 22 percent of sampled wells exceeded the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) for arsenic of 10 μg/L, with arsenic concentrations commonly exceeding the MCL in water from wells east of Barstow, deep wells in the Victorville fan, and in suboxic or reduced groundwater within the floodplain aquifer. Water from about 1 percent of sampled wells had Cr(VI) concentrations greater than the California MCL for total chromium of 50 μg/L, whereas 13 percent of sampled wells had Cr(VI) concentrations greater than the former California MCL of 10 μg/L. Hexavalent chromium concentrations were highest in water from wells in the Sheep Creek alluvial fan, eroded from mafic rock in the San Gabriel Mountains, although Cr(VI) concentrations greater than the former California MCL also were present elsewhere in the study area where mafic materials or older groundwater were present. Water from about 9 percent of sampled wells exceeded the EPA MCL for uranium of 30 μg/L, with concentrations exceeding the MCL commonly associated with irrigation return from agricultural land overlying the floodplain aquifer. Water from about 7 percent of sampled wells had vanadium concentrations greater than the California notification level of 50 μg/L; most of these wells were in the Victorville fan within the Mojave River area. In general, arsenic concentrations were higher in suboxic or reduced water; chromium concentrations were higher in oxic, alkaline (pH≥7.5) water; uranium concentrations were higher in circumneutral to slightly alkaline water (pH≤7.4); and vanadium concentrations were higher in highly alkaline (pH≥8.0) water, independent of redox status. Concentrations within geologic source terranes are not the sole factor controlling the concentrations of geogenic elements in groundwater. Differences in mineral weathering, pH-dependent sorption to surface-exchange sites on mineral grains, and aqueous geochemistry (especially redox status and pH) affect geogenic element concentrations in groundwater. Consequently, the relative abundances of arsenic, Cr(VI), uranium, and vanadium in groundwater differ from their relative abundances in the average bulk continental crust and their regional abundances in rock and surficial alluvium within groundwater basins of the western Mojave Desert. Processes that control the concentrations of arsenic, chromium, uranium, and vanadium in groundwater operate at the mineral-grain and aquifer scale. At the mineral-grain scale, sequential chemical extraction data show arsenic and uranium are more available to groundwater (under specific geochemical conditions) than chromium or vanadium, which largely are unavailable within unweathered mineral grains. Additionally, chromium and vanadium form few aqueous complexes and bind tightly with iron minerals within surface coatings on mineral grains making them less available to groundwater, whereas complexation with other dissolved ions enhances the solubility of uranium and, to a lesser extent, arsenic. Complexation also increases the valence (less negative charge) and increases the size of dissolved oxyanions and uranium complexes with bicarbonate and carbonate making them less readily sorbed to aquifer materials. At the aquifer scale, hydrogeology (including isolation of water in aquifers from surface sources of recharge, older groundwater age, and long contact times between groundwater and aquifer materials) combined with geochemical processes (such as silicate weathering) to produce alkaline groundwater. Desorption from sorption sites on the surfaces of mineral grains with increasing pH increases arsenic, chromium, and vanadium concentrations in water from wells and increases Cr(VI) concentrations as long as water remains oxic. Aqueous geochemistry and concentrations of geogenic contaminants also are affected by anthropogenic activities including (1) discharge of treated municipal wastewater, which may change the redox status of groundwater; (2) return from irrigated agriculture, which may alter the chemistry of groundwater and increase the solubility of trace elements such as uranium; and (3) groundwater pumping and subsequent water-level declines, which may change the source of water yielded by wells. The quality of water imported from northern California and infiltrated from ponds for groundwater recharge may be altered by naturally present trace elements, especially uranium in areas of agricultural land use or chromium within mafic alluvium.

California↗

Organochlorine compounds and trace elements in fish tissue and streambed sediment in the Mobile River Basin, Alabama, Mississippi, and Georgia, 1998

During the summer of 1998, as part of the National Water-Quality Assessment Program, a survey was conducted to determine which organochlorine compounds and trace elements occur in fish tissues and streambed sediments in the Mobile River Basin, which includes parts of Alabama, Mississippi, Georgia, and Tennessee. The data collected were compared to guidelines related to wildlife, land use, and to 1991 and 1994 National Water-Quality Assessment Program Study-Unit data.Twenty-one sites were sampled in subbasins of the Mobile River Basin. The subbasins ranged in size from about 9 to 22,000 square miles and were dominated by either a single land use or a combination of land uses. The major land-use categories were urban, agriculture, and forest.Organochlorine compounds were widespread spatially in the Mobile River Basin. At least one organochlorine compound was reported at the majority of sampling sites (84 percent) and in a majority of whole-fish (80 percent) and streambed-sediment (52 percent) samples. Multiple organochlorine compounds were reported at 75 percent of the sites where fish tissues were collected and were reported at many of the streambed-sediment sampling sites (45 percent). The majority of concentrations reported, however, were less than 5 micrograms per kilogram in fish-tissue samples and less than 1 microgram per kilogram in streambed-sediment samples.The majority of trace elements analyzed in fish-liver tissue (86 percent) and streambed-sediment (98 percent) samples were reported during this study. Multiple trace elements were reported in all samples and at all sites.Based on comparisons of concentrations of organochlorine compounds and trace elements in fish-tissue and streambed-sediment samples in relation to National Academy of Science and National Academy of Engineering and Canadian tissue guidelines, probable-effects concentrations, and mean probable-effects concentration quotients for streambed sediment, the potential exists for adverse effects to wildlife at 15 (72 percent) of the sites sampled. The potential for adverse effects at these sites is because of the presence of residues or breakdown products related to polychlorinated biphenyls (PCB?s), chlordane, dichlorodiphenyltrichloroethane (DDT), chromium, lead, and zinc.The majority of compounds reported (65 percent) were chlordane, DDT, and PCB?s, or their breakdown products. Concentrations of chlordane and heptachlor epoxide in whole-fish tissue were positively correlated to the amount of urban land use in a basin. Total DDT concentrations in whole-fish tissues were positively correlated to agriculture.The relation of trace elements to land use is not as clear as the relation of organochlorine compounds to land use. This lack of clarity may be due to the possibility of geologic sources of trace elements in the Mobile River Basin and to the ubiquitous nature of many of these trace elements. However, there may be a correlation between the amount of urban land use and concentrations of antimony, cadmium, lead, and zinc in streambed-sediment samples from the Mobile River Basin.Fewer organochlorine compounds and trace elements were reported in samples from the Mobile River Basin than in samples collected during the 1991 and 1994 National Water-Quality Assessment Program studies. Of the organochlorine compounds analyzed nationally, 57 percent were reported in whole-fish tissue samples collected locally and 41 percent were reported in streambed-sediment samples collected locally, whereas 96 percent and 86 percent, respectively, were reported nationally. Of trace elements analyzed nationally, 86 percent were reported in fish-liver tissue locally and 95 percent were reported in streambed-sediment samples locally, whereas 95 percent and 98 percent, respectively, were reported nationally.In general, concentrations of organochlorine compounds and trace elements and the frequency with which they were reported in the Mobile River Basin are similar to or less than t

Alabama, Georgia, Mississippi, Tennessee↗

Concentrations and Distribution of Slag-Related Trace Elements and Mercury in Fine-Grained Beach and Bed Sediments of Lake Roosevelt, Washington, April-May 2001

A series of studies have documented elevated concentrations of trace elements such as arsenic, cadmium, copper, lead, mercury, and zinc in the water, bed sediment, or fish of Lake Roosevelt and the upstream reach of the Columbia River. Elevated concentrations of some trace elements in this region are largely attributable to the transport of slag and metallurgical waste discharged into the Columbia River from a smelter in Canada. Although most recent studies have focused on contamination levels in water, bed sediment, and fish, there is growing concern in the region over the potential threat of airborne contaminants to human health. In response to these concerns, the U.S. Geological Survey conducted an assessment of trace-element concentrations in the relatively shallow fine-grained sediment along the shore of Lake Roosevelt that is exposed annually during periods of reservoir drawdown. During each winter and spring, the water level of Lake Roosevelt is lowered as much as about 80 feet to provide space to capture high river flows from spring runoff, exposing vast expanses of lake-bottom sediment for a period of several months. Upon drying, these exposed areas provide an extremely large source for wind-blown dust. This study concluded that trace elements associated with slag and metallurgical waste are present in the fine-grained fraction (less than 63 micrometers) of bed sediments along the length of Lake Roosevelt, and as such, could be components of the airborne dust resulting from exposure, drying, and wind mobilization of the sediments exposed during the annual drawdowns of the reservoir. Trace-element concentrations in the surficial bed sediment varied, but the major components in slag?arsenic, cadmium, copper, lead, and zinc?showed generally pronounced gradients of decreasing concentrations from near the International Border to the Grand Coulee Dam. The results of this study provide base-line information needed to plan and conduct air monitoring of trace elements in wind-blown dust along Lake Roosevelt.

Water-Resources Investigations Report↗

Geochemical and hydrologic data for wells and springs in thermal-spring areas of the Appalachians

Current interest in geothermal potential of thermal-spring areas in the Appalachians enhances the value of data on thermal springs and wells in these areas. This report presents maps showing locations of selected springs and wells and tables of physical and chemical data pertaining to these wells and springs. The chemical tables show compositions of gases (oxygen, nitrogen, argon, methane, carbon dioxide, and helium), isotope contents (tritium, carbon-13, and oxygen-18), trace and minor element chemical data, and concentrations of the major chemical constituents.

Water-Resources Investigations Report↗

National Water-Quality Assessment Program, western Lake Michigan drainages: Summaries of liaison committee meeting, Green Bay, Wisconsin, March 28-29, 1995

The Western Lake Michigan Drainages (WMIC) study unit, under investigation since 1991, drains 20,000 square miles (mi2) in eastern Wisconsin and Upper Michigan (fig. 1). The major water-quality issues in the WMIC study unit are: (1) nonpoint-source contamination of surface and ground water by agricultural chemicals, (2) contamination in bottom sediments of rivers and harbors by toxic substances, including polychlorinated biphenyls (PCB's), other synthetic organic compounds, and trace elements, (3) nutrient enrichment of rivers and lakes resulting from nonpoint- and point-source discharges, and (4) acidification and mercury contamination of lakes in poorly buffered watersheds in the northwestern part of the study unit. A study-unit liaison committee, which includes representatives of Federal, State, university, and private and citizen organizations, has met annually since 1991 to review plans and results and guide the investigators toward policy-relevant efforts. The results of research conducted in the WMIC study unit by U.S. Geological Survey (USGS) and non-USGS researchers were presented at the liaison committee meeting held in Green Bay, Wis., on March 28-29, 1995. This report contains summaries of the oral presentations given at the WMIC 1995 liaison committee meeting.

Michigan, Wisconsin↗

The chemistry of hydrothermal magnetite: a review

Magnetite (Fe 3 O 4 ) is a well-recognized petrogenetic indicator and is a common accessory mineral in many ore deposits and their host rocks. Recent years have seen an increased interest in the use of hydrothermal magnetite for provenance studies and as a pathfinder for mineral exploration. A number of studies have investigated how specific formation conditions are reflected in the composition of the respective magnetite. Two fundamental questions underlie these efforts — (i) How can the composition of igneous and, more importantly, hydrothermal magnetite be used to discriminate mineralized areas from barren host rocks, and (ii) how can this assist exploration geologists to target ore deposits at greater and greater distances from the main mineralization? Similar to igneous magnetite, the most important factors that govern compositional variations in hydrothermal magnetite are (A) temperature, (B) fluid composition — element availability, (C) oxygen and sulfur fugacity, (D) silicate and sulfide activity, (E) host rock buffering, (F) re-equilibration processes, and (G) intrinsic crystallographic controls such as ionic radius and charge balance. We discuss how specific formation conditions are reflected in the composition of magnetite and review studies that investigate the chemistry of hydrothermal and igneous magnetite from various mineral deposits and their host rocks. Furthermore, we discuss the redox-related alteration of magnetite (martitization and mushketovitization) and mineral inclusions in magnetite and their effect on chemical analyses. Our database includes published and previously unpublished magnetite minor and trace element data for magnetite from (1) banded iron formations (BIF) and related high-grade iron ore deposits in Western Australia, India, and Brazil, (2) Ag–Pb–Zn veins of the Coeur d'Alene district, United States, (3) porphyry Cu–(Au)–(Mo) deposits and associated (4) calcic and magnesian skarn deposits in the southwestern United States and Indonesia, and (5) plutonic igneous rocks from the Henderson Climax-type Mo deposit, United States, and the un-mineralized Inner Zone Batholith granodiorite, Japan. These five settings represent a diverse suite of geological settings and cover a wide range of formation conditions. The main discriminator elements for magnetite are Mg, Al, Ti, V, Cr, Mn, Co, Ni, Zn, and Ga. These elements are commonly present at detectable levels (10 to > 1000 ppm) and display systematic variations. We propose a combination of Ni/(Cr + Mn) vs. Ti + V, Al + Mn vs. Ti + V, Ti/V and Sn/Ga discriminant plots and upper threshold concentrations to discriminate hydrothermal from igneous magnetite and to fingerprint different hydrothermal ore deposits. The overall trends in upper threshold values for the different settings can be summarized as follows: (I) BIF (hydrothermal) — low Al, Ti, V, Cr, Mn, Co, Ni, Zn, Ga and Sn; (II) Ag–Pb–Zn veins (hydrothermal) — high Mn and low Ga and Sn; (III) Mg-skarn (hydrothermal) — high Mg and Mn and low Al, Ti, Cr, Co, Ni and Ga; (IV) skarn (hydrothermal) — high Mg, Al, Cr, Mn, Co, Ni and Zn and low Sn; (V) porphyry (hydrothermal) — high Ti and V and low Sn; (VI) porphyry (igneous) — high Ti, V and Cr and low Mg; and (VII) Climax-Mo (igneous) — high Al, Ga and Sn and low Mg and Cr.

Ore Geology Reviews↗

Water-Quality Conditions of Chester Creek, Anchorage, Alaska, 1998-2001

Between October 1998 and September 2001, the U.S. Geological Survey's National Water-Quality Assessment Program evaluated the water-quality conditions of Chester Creek, a stream draining forest and urban settings in Anchorage, Alaska. Data collection included water, streambed sediments, lakebed sediments, and aquatic organisms samples from urban sites along the stream. Urban land use ranged from less than 1 percent of the basin above the furthest upstream site to 46 percent above the most downstream site. Findings suggest that water quality of Chester Creek declines in the downstream direction and as urbanization in the watershed increases. Water samples were collected monthly and during storms at a site near the stream's mouth (Chester Creek at Arctic Boulevard) and analyzed for major ions and nutrients. Water samples collected during water year 1999 were analyzed for selected pesticides and volatile organic compounds. Concentrations of fecal-indicator bacteria were determined monthly during calendar year 2000. During winter, spring, and summer, four water samples were collected at a site upstream of urban development (South Branch of South Fork Chester Creek at Tank Trail) and five from an intermediate site (South Branch of South Fork Chester Creek at Boniface Parkway). Concentrations of calcium, magnesium, sodium, chloride, and sulfate in water increased in the downstream direction. Nitrate concentrations were similar at the three sites and all were less than the drinking-water standard. About one-quarter of the samples from the Arctic Boulevard site had concentrations of phosphorus that exceeded the U.S. Environmental Protection Agency (USEPA) guideline for preventing nuisance plant growth. Water samples collected at the Arctic Boulevard site contained concentrations of the insecticide carbaryl that exceeded the guideline for protecting aquatic life. Every water sample revealed a low concentration of volatile organic compounds, including benzene, toluene, tetrachloroethylene, methyl tert-butyl ether, and chloroform. No water samples contained volatile organic compounds concentrations that exceeded any USEPA drinking-water standard or guideline. Fecal-indicator bacteria concentrations in water from the Arctic Boulevard site commonly exceeded Federal and State guidelines for water-contact recreation. Concentrations of cadmium, copper, lead, and zinc in streambed sediments increased in the downstream direction. Some concentrations of arsenic, chromium, lead, and zinc in sediments were at levels that can adversely affect aquatic organisms. Analysis of sediment chemistry in successive lakebed-sediment layers from Westchester Lagoon near the stream's mouth provided a record of water-quality trends since about 1970. Concentrations of lead have decreased from peak levels in the mid-1970s, most likely because of removing lead from gasoline and lower lead content in other products. However, concen-trations in recently-deposited lakebed sediments are still about 10 times greater than measured in streambed sediments at the upstream Tank Trail site. Zinc concentrations in lakebed sediments also increased in the early 1970s to levels that exceeded guidelines to protect aquatic life and have remained at elevated but variable levels. Pyrene, benz[a]anthracene, and phenanthrene in lakebed sediments also have varied in concentrations and have exceeded protection guidelines for aquatic life since the 1970s. Concentrations of dichloro-diphenyl-trichloroethane, polychlorinated biphenyls (PCBs), or their by-products generally were highest in lakebed sediments deposited in the 1970s. More recent sediments have concentrations that vary widely and do not show distinct temporal trends. Tissue samples of whole slimy sculpin (Cottus cognatus), a non-migratory species of fish, showed con-centrations of trace elements and organic contaminants. Of the constituents analyzed, only selenium concentra-tions showed levels of potential concern for

Scientific Investigations Report↗