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At least 451 records · Page 25Linked to original sources
USGS1996

Water-quality assessment of the Albermarle-Pamlico drainage basin, North Carolina and Virginia— A summary of selected trace element, nutrient, and pesticide data for bed sediments, 1969-90

Spatial distributions of metals and trace elements, nutrients, and pesticides and polychiorinated biphenyls (PCB's) in bed sediment were characterized using data collected from 1969 through 1990 and stored in the U.S. Geological Survey's National Water Data Storage and Retrieval (WATSTORE) system and the U.S. Environmental Protection Agency's Storage and Retrieval (STORET) system databases. Bed-sediment data from WATSTORE and STORET were combined to form a single database of 1,049 records representing 301 sites. Data were examined for concentrations of 16 metals and trace elements, 4 nutrients, 10 pesticides, and PCB's. Maximum bed-sediment concentrations were evaluated relative to sediment-quality guidelines developed by the National Oceanic and Atmospheric Administration, the Ontario Ministry of Environment and Energy, and the Virginia Department of Environmental Quality. Sites were not selected randomly; therefore, results should not be interpreted as representing average conditions. Many sites were located in or around lakes and reservoirs, urban areas, and areas where special investigations were conducted. Lakes and reservoirs function as effective sediment traps, and elevated concentrations of some constituents occurred at these sites. High concentrations of many metals and trace elements also occurred near urban areas where streams receive runoff or inputs from industrial, residential, and municipal activities. Elevated nutrient concentrations occurred near lakes, reservoirs, and the mouths of major rivers. The highest concentrations of arsenic, beryllium, chromium, iron. mercury, nickel, and selenium occurred in the Roanoke River Basin and may be a result of geologic formations or accumulations of bed sediment in lakes and reservoirs. The highest concentrations of cadmium, lead, and thallium were detected in the Chowan River Basin; copper and zinc were reported highest in the Neuse River Basin. Total phosphorus and total ammonia plus organic nitrogen concentrations exceeded the sediment evaluation guidelines in each major river basin, possibly resulting from wastewater inputs and agricultural applications. Exceedances of pesticide guidelines were detected in the upper Neuse River Basin near Falls Lake and in the lower Tar River Basin.

North Carolina, Virginia↗
USGS1997

Nutrient and trace-element enrichment of Coeur d'Alene Lake, Idaho

The limnological characteristics and geochemistry of lakebed sediments in Coeur d'Alene Lake were assessed during 1991-92 because of the possible interaction of nutrient enrichment with the highly enriched trace-element concentrations stored in the lakebed. The scope included characterization of physical, chemical, and biological variables; quantification of hydrologic, nutrient, and trace-element budgets; development of an empirical nutrient load/lake response model; and characterization of trace elements in surficial and subsurface lakebed sediments.

Water Supply Paper↗
USGS1995

Assimilation of trace elements ingested by the mussel Mytilus edulis: Effects of algal food abundance

Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements ( 110m Ag, 241 Am, 109 Cd, 57 Co, 75 Se and 65 Zn) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h -1 ). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with ingestion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis . In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels.

Marine Ecology Progress Series↗
USGS2024

Potentially toxic elements in wild Agassiz’s desert tortoises: Tissue concentrations and association with disease

Background: Desert tortoise ( Gopherus agassizii ) populations have continued to decline due to infectious and other diseases, predation, and habitat alteration. The potential contribution of minerals and heavy metals to tortoise health and susceptibility to disease remains uncertain. Objective: The objective of this study was to evaluate the results of elemental analysis of trace minerals and macrominerals in scute keratin, kidney, and liver tissue from ill and dying desert tortoises salvaged for necropsy between 1993 and 2000. Methods: Salvaged tortoises were categorized by age (adult, juvenile), geographic location, and primary disease based on necropsy findings. A subset of tortoises that were injured or killed by vehicular trauma or predation but with no notable pathologic abnormalities were used as controls. A panel of 21 trace minerals and 6 macrominerals was analyzed in scute keratin, kidney, and liver tissue samples by inductively-coupled plasma spectrometry and atomic absorption spectrophotometry. Results: Necropsies were done on 46 tortoises, including 9 juveniles salvaged from 5 regions in the Colorado and Mojave deserts of California. Primary diseases were cutaneous dyskeratosis (n=9), infection/ inflammation (n=8), malnutrition (n=7), mycoplasmosis (n=5), and urolithiasis (n=3); 14 tortoises were classified as controls. Concentrations of elements differed significantly by tissue, age, desert region, and disease (P < 0.05). Tortoises with cutaneous dyskeratosis had significantly higher Se concentrations, primarily in keratin and liver, than tortoises with other diseases (P < 0.001). Juveniles were more likely than adults to have high Pb, Sn, and Zn levels (P < 0.05). All tortoises had detectable levels of more than one potentially toxic heavy metal, including As, Cd, Cr, Hg, Ni, Pb, Sn and V. Conclusions: Potentially toxic elements are frequently found in tissue from tortoises in desert regions of California, with significantly higher concentrations in diseased tortoises. Metal exposure from soils, mining, historic and ongoing military activities, and other human activities could increase susceptibility to disease in desert tortoises.

California↗
USGS2013

Normalized rare earth elements in water, sediments, and wine: identifying sources and environmental redox conditions

The concentrations of the rare earth elements (REE) in surface waters and sediments, when normalized on an element-by-element basis to one of several rock standards and plotted versus atomic number, yield curves that reveal their partitioning between different sediment fractions and the sources of those fractions, for example, between terrestrial-derived lithogenous debris and seawater-derived biogenous detritus and hydrogenous metal oxides. The REE of ancient sediments support their partitioning into these same fractions and further contribute to the identification of the redox geochemistry of the sea water in which the sediments accumulated. The normalized curves of the REE that have been examined in several South American wine varietals can be interpreted to reflect the lithology of the bedrock on which the vines may have been grown, suggesting limited fractionation during soil development.

American Journal of Analytical Chemistry↗
USGS2020

Book review: Rare earth element resources: Indian context

Rare Earth Element Resources: Indian Context. Yamuna Singh. 2020. ISBN 978-3-030-41353-8. Society of Earth Scientists Series, Springer, Cham, Switzerland, 269 Pp. Hardcover and eBook. €93.08 Rare Earth Element Resources: Indian Context by Yamuna Singh provides an excellent review of rare earth element (REE) deposits and occurrences in India with an emphasis on placer deposits, India’s most notable REE resource. This 269-page, 10-chapter book not only describes REE occurrences but also provides introductory material on REE geochemistry and discusses other potential industrial sources including recycling, fly ash, and mine waste products. The book concludes with a chapter on the state of the REE industry in India and discusses possible future trends and needs. Anyone interested in exploring for REEs in India will find this book from Springer’s Society of Earth Scientists series a useful reference.

Economic Geology↗
USGS2022

Trace elements in quartz: Insights into source and fluid evolution in magmatic-hydrothermal systems

Quartz trace elements record information about fluid evolution as well as metal migration and precipitation. Here, we summarize most of the reported (including this study) quartz trace element data ( N = ~4,600) generated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) on various textural types and paragenetic stages of quartz in I-type porphyry-epithermal (Cu-Mo-Au-Ag-Te) and S- and A-type granitegreisen (Sn-W and rare metal) systems in the world. The results show that Li versus Al diagrams, combined with Ti-Ge-As-Sb contents, can be used to decipher the source and evolution of fluids in magmatic-hydrothermal systems. In I-type porphyry-epithermal systems, magmatic quartz has low Li/Al ratios from 0.001 to 0.173 ( N = 483) with a mean of 0.039 ± 0.032. Hydrothermal quartz has progressively higher Li and Al concentrations that are dominated by cooling along fluid pathways. Quartz evolves from Ti rich to Ge rich from early to late stages in porphyry hydrothermal veins and is As and Sb rich in epithermal veins. In S- and A-type granite-greisen systems, magmatic quartz has high Li/Al ratios from 0.007 to 0.502 ( N = 604) with a mean of 0.130 ± 0.063 and from 0.009 to 0.327 ( N = 325) with a mean of 0.126 ± 0.065, respectively. Hydrothermal quartz has progressively lower Li and Al concentrations that are dominated by fluid-rock reactions and cooling along fluid pathways. Quartz evolves with decreasing Ti concentrations from magmatic to hydrothermal stages. Ge is abundant in pegmatite quartz in S-type systems. Variations in pH or precipitation rate along fluid pathways have a small influence on Li/Al ratios. The variation of quartz trace elements with elevation in individual systems suggests that they can be used as a vector to guide exploration in magmatic-hydrothermal systems.

Economic Geology↗
USGS2024

Apatite and monazite geochemistry record magmatic and metasomatic processes in rare earth element mineralization at Mountain Pass, California

The largest rare earth element (REE) deposit in the United States is a carbonatite intrusion at Mountain Pass in the Mojave Desert, California. Despite a clear spatiotemporal association of alkaline silicate and carbonatite intrusions at Mountain Pass, a genetic model of their mutual formation has not been resolved. The Mountain Pass carbonatite has long been upheld as an example of a primary magmatic body, but recent work has suggested it could be fluid-derived. This study investigates the geochemistry of apatite and monazite grains from the alkaline silicate and carbonatite stocks and dikes of the Mountain Pass district, to elucidate the magmatic history of the intrusive suite and identify the role of fluids in rare earth element mineralization. Three apatite populations are identified in the alkaline silicate rocks. A primary magmatic apatite group supports intrusion of the stocks as separate pulses of magma derived from a spatially extensive metasomatized mantle source region. The second group implicates the role of a regional fluid that mobilized light rare earth elements from apatite grains. A minor group of inherited apatite cores, identified by low Sr and negative Eu anomalies, supports assimilation of crustal material in the formation of the intrusive suite. Analyses of monazite and apatite grains from the carbonatite orebody also reveal a mix of primary magmatic and metasomatic (fluid-related) minerals. Compositional similarities between primary phosphates in the carbonatite and alkaline silicate rocks support a genetic link between the intrusive suites. The presence of fluids regionally and within the carbonatite orebody indicates the Mountain Pass carbonatite should not be classified as a purely magmatic REE deposit.

Arizona, California, Nevada↗
USGS1985

DISTRIBUTION OF TRACE ELEMENTS IN COAL MINERALS OF SELECTED EASTERN UNITED STATES COALS.

The association of 34 elements with minerals found in coal was determined by a combination of analytical techniques on size and density fractions of low-temperature ash (LTA). Instrumental neutron activation analysis was used to determine the concentrations of the elements, and X-ray diffraction analysis, scanning electron microscopy, and scanning transmission electron microscopy were used to identify the minerals present in the LTA. The distribution of elemental and mineral concentrations in different size fractions was also determined. Between 35 and 60 weight percent of the LTA was composed of particles smaller than 2 mu m.

Conference Paper↗
USGS1985

Elemental X-ray mapping of agglutinated foraminifer tests: A non- destructive technique for determining compositional characteristics.

The composition of agglutinated foraminiferal tests vary remarkably in response to local substrate characteristics, physiochemical properties of the water column and species- dependant selectivity of test components. We have employed a technique that combines a scanning electron microscope with an energy dispersive X-ray spectrometer system to identify major and minor elemental constituents of agglutinated foraminiferal walls. As a sample is bombarded with a beam of high energy electrons, X-rays are generated that are characteristic of the elements present. As a result, X- ray density maps can be produced for each of several elements present in the tests of agglutinated foraminifers.

Micropaleontology↗
USGS1987

PROTON MICROPROBE ANALYSIS OF TRACE-ELEMENT VARIATIONS IN VITRINITES IN THE SAME AND DIFFERENT COAL BEDS.

The PIXE (proton-induced X-ray emission) microprobe can be used for nondestructive, in-situ analyses of areas as small as those analyzed by the electron microprobe, and has a sensitivity of detection as much as two orders of magnitude better than the electron microprobe. Preliminary studies demonstrated that PIXE provides a capability for quantitative determination of elemental concentrations in individual coal maceral grains with a detection limit of 1-10 ppm for most elements analyzed. Encouraged by the earlier results, we carried out the analyses reported below to examine trace element variations laterally (over a km range) as well as vertically (cm to m) in the I and J coal beds in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in central Utah, and to compare the data with the data from two samples of eastern coals of Pennsylvanian age.

Scanning Micros↗
USGS1990

Enzyme leaching of surficial geochemical samples for detecting hydromorphic trace-element anomalies associated with precious-metal mineralized bedrock buried beneath glacial overburden in northern Minnesota

One objective of the International Falls and Roseau, Minnesota, CUSMAP projects was to develop a means of conducting regional-scale geochemical surveys in areas where bedrock is buried beneath complex glacially derived overburden. Partial analysis of B-horizon soils offered hope for detecting subtle hydromorphic trace-element dispersion patterns. An enzyme-based partial leach selectively removes metals from oxide coatings on the surfaces of soil materials without attacking their matrix. Most trace-element concentrations in the resulting solutions are in the part-per-trillion to low part-per-billion range, necessitating determinations by inductively coupled plasma/mass spectrometry. The resulting data show greater contrasts for many trace elements than with other techniques tested. Spatially, many trace metal anomalies are locally discontinuous, but anomalous trends within larger areas are apparent. In many instances, the source for an anomaly seems to be either basal till or bedrock. Ground water flow is probably the most important mechanism for transporting metals toward the surface, although ionic diffusion, electrochemical gradients, and capillary action may play a role in anomaly dispersal. Sample sites near the Rainy Lake-Seine River fault zone, a regional shear zone, often have anomalous concentrations of a variety of metals, commonly including Zn and/or one or more metals which substitute for Zn in sphalerite (Cd, Ge, Ga, and Sn). Shifts in background concentrations of Bi, Sb, and As show a trend across the area indicating a possible regional zoning of lode-Au mineralization. Soil anomalies of Ag, Co, and Tl parallel basement structures, suggesting areas that may have potential for Cobalt/Thunder Baytype silver viens. An area around Baudette, Minnesota, which is underlain by quartz-chlorite-carbonate-altered shear zones, is anomalous in Ag, As, Bi, Co, Mo, Te, Tl, and W. Anomalies of Ag, As, Bi, Te, and W tend to follow the fault zones, suggesting potential for lode-Au deposits. Soil anomalies of Co, Mo, and Tl appear to follow northwest-striking structures that cross the shear zones, suggesting that Thunder Bay-type mineralization may have overprinted earlier mineralization along the shear zones.

Conference Paper↗
USGS1994

Geochemistry of the 1989-1990 eruption of redoubt volcano: Part I. Whole-rock major- and trace-element chemistry

The 1989-1990 eruption of Redoubt Volcano produced medium-K calc-alkaline andesite and dacite of limited compositional range (58.2-63.4% SiO2) and entrained quenched andesitic inclusions (55% SiO2) which bear chemical similarities to the rest of the ejecta. The earliest (December 15) magmas are pumiceous, often compositionally banded, and the majority is relatively mafic (< 59% SiO2). The most silicic magmas of the eruption are the late December to early January domes (up to 63.4% SiO2). Subsequent magmas formed domes and rare pumices which converge on 60% SiO2. Chemical variations among ejecta comprise tight, linear, two-component arrays for all elements for which the analytical uncertainty is much less than the compositional range. The two-component arrays are interpreted as mixing arrays between unrelated magmas because several of the arrays are at steep angles to the normal liquid line of descent. Additionally, the felsic endmember cannot be easily related to the mafic endmember by normal high-temperature igneous processes (e.g., the silicic endmember has higher Zr yet lower Hf than the mafic endmember). Also relative enrichments of highly incompatible elements are dramatically different across the arrays. The mixing event must have preceded eruption by a significant, yet unspecified amount of time because groundmass glass compositions are homogeneous for all post-December samples (Swanson et al., 1994-this volume), in spite of the whole-rock chemical diversity. This implies time for additional crystallization after the mixing event. Swanson et al. (1994-this volume) discuss evidence for a potentially different mixing event recorded only in December 15 magmas. Cognate cumulate xenoliths composed of pl+cpx+opx+hb+mt+melt were recovered from January and April deposits. These blocks differ from local batholithic country rock in their low concentrations of incompatible elements (e.g., Rb < 5 ppm vs 20-90 ppm, Ba < 150 ppm vs 300-2000 ppm) and low SiO2 (< 50 wt.% vs > 60 wt.%). They have Mg, Cr, Ni, Sc, and V contents higher than the andesites, but lower than Redoubt basalts and basaltic andesites. Thus, they may be crystallization products of andesites, but do not represent the cumulate residue of basalt fractionation. The xenoliths were probably derived from a shallow or intermediate crustal chamber. ?? 1994.

Journal of Volcanology and Geothermal Research↗
USGS1996

Paragenetic and minor- and trace-element studies of Mississippi Valley-type ore deposits of the Silesian-Cracow district, Poland

Paragenetic and minor- and trace-element studies were conducted on samples of epigenetic ore and gangue minerals collected from mines and drill core in the Silesian-Cracow (S-C) district of southern Poland. Four discrete mineral suites representing four mineralizing stages can be identified throughout the district. The earliest epigenetic minerals deposited during stage 1 consist of a late dolomite cement together with minor pyrite and marcasite. Stage 2 was the first ore-forming stage and included repetitive deposition of sphalerite and galena in a variety of morphologies. Stage 3 abruptly followed the first ore stage and deposited marcasite and pyrite with variable amounts of late sphalerite and galena. In the samples studied, minerals deposited during stage 3 are predominately marcasite-pyrite with minor sphalerite and galena in the Pomorzany and Olkusz mines, whereas, at the Trzebionka mine, stage 3 mineralization deposited mostly galena and sphalerite with little marcasite or pyrite. Stage 4 minerals include contains barite, followed by calcite, with very minor pyrite and a rare, late granular sphalerite. Compared to other major Mississippi Valley-type (MVT) districts of the world, the Silesian-Cracow district contains sphalerite with the second largest range in Ag concentrations and the largest range in Fe and Cd concentrations of any district. Unlike in other districts, very wide ranges in minor- and trace-element concentrations are also observed in paragenetically equivalent samples collected throughout the district. This wide range indicates that the minor- and trace-element content of the ore-forming environment was highly variable, both spatially and temporally, and suggests that the hydrologic system that the ore fluids traversed from their basinal source was very complex. Throughout the district, a significant increase in Tl, Ge, and As concentrations is accompanied by a lightening of sulfur isotopes between stage 2 and stage 3 minerals. This change appears to record a major district-scale hydrologic event that probably reflects the introduction of fluids with significantly different geochemistry than that of earlier ore-forming fluids.

Prace - Panstwowego Instytutu Geologicznego↗
USGS1995

Scale as a factor in designing sampling programs for determination of annual trace element fluxes

Concentration data of suspended sediment-associated trace elements are a requisite for estimation of annual chemical fluxes. Fluvial suspended sediment and associated trace elements display marked shortterm spatial and temporal variability, suggesting that determination of annual fluxes requires high frequency depth and width integrated sampling and subsequent chemical analyses. When time scales are shifted from hours or days to a year, short-term variability is less important. A 2 year study on the Arkansas River indicates that it may be possible, after detailed site characterization of mean/median sediment chemical data, to estimate annual fluxes of trace elements solely through monitoring of discharge and suspended sediment concentration.

Effects of scale on interpretation and management ↗
USGS2016

Critical elements in sediment-hosted deposits (clastic-dominated Zn-Pb-Ag, Mississippi Valley-type Zn-Pb, sedimentary rock-hosted Stratiform Cu, and carbonate-hosted Polymetallic Deposits): A review: Chapter 12

Some sediment-hosted base metal deposits, specifically the clastic-dominated (CD) Zn-Pb deposits, carbonate-hosted Mississippi Valley-type (MVT) deposits, sedimentary-rock hosted stratiform copper deposits, and carbonate-hosted polymetallic (“Kipushi type”) deposits, are or have been important sources of critical elements including Co, Ga, Ge, and Re. The generally poor data concerning trace element concentrations in these types of sediment-hosted ores suggest that there may be economically important concentrations of critical elements yet to be recognized.

Book chapter↗
USGS2009

Distribution of major anions and trace elements in the unsaturated zone at Franklin Lake Playa, California, USA

The composition of surficial salts formed near dry and drying saline lakes are partly the product of processes active in the unsaturated zone between the ground surface and the water table. These processes were investigated by determining the abundance of water-extractable solutes in sediment from the ground surface to the water table (~2.8 m) beneath Franklin Lake playa, California. Accumulation of solutes in the sediment is attributed to evaporation of aqueous solutions transported upward from the water table through the capillary fringe to an evaporation font that is currently 20-30 cm below the ground surface. Salts in the sediment from 0 to 20 cm depth are depleted in chloride and enriched in carbonate relative to deeper samples. Chloride depletion is most likely a product of selective dissolution by vertical recharge. The entire unsaturated zone contains greater amounts of carbonate than expected for evaporation of ground water and is best explained by preferential dissolution of more soluble salts in recharging precipitation but may also reflect the assimilation of CO2 as carbonate minerals precipitate. Variations in the concentrations of arsenic, molybdenum, tungsten, and uranium in the water-soluble fraction of the sediment are complex and suggest unique geochemical controls on the abundance of each element. The distribution of these trace element abundances indicates the arsenic is the element most likely to accumulate in near-surface salts.

California↗
USGS2024

Conventional rare earth element mineral deposits: The global landscape

Four conventional mineral deposit types—carbonatite, alkaline igneous, heavy mineral sand, and regolith-hosted ion-adsorption clay deposits—currently supply global markets with the rare earth elements (REEs) and rare earth oxides (REOs) necessary to meet the technological needs of global communities. The unique properties of REEs make them useful in a wide variety of applications, such as alloys, batteries, catalysts, magnets, phosphors, and polishing compounds. Rare earth element minerals are complex in both composition and structure. Carbonate, oxide, silicate, and phosphate-type minerals contain highly variable amounts of rare earths. Most rare earth-bearing minerals contain mainly lighter rare earths, a mixture of all the rare earths, or only the heavier rare earths. Diverse technological applications require the full range of light, middle, and heavy rare earths. The production of these elements, in particular the heavy rare earths, remains highly dependent on deposits from China. Diversification of rare earth supply chains is contingent on expanded knowledge of globally distributed resources and an understanding of the degree to which those resources have been explored and evaluated. The knowledge of tectonic setting, typical rock associations, deposit morphology, and deposit genesis has led to the discovery of many conventional-type rare earth deposit types. Recent developments are anticipated to result in further discoveries that have the potential to meet the ever-expanding applications of REEs and REOs to address modern societal needs.

Book chapter↗