Filters: Tags: Metals (X)
137 results (215ms)|
Filters
Date Range
Extensions Types Contacts
Categories Tag Types
|
Recent advances in mass spectrometry have allowed isotope scientists to precisely determine stable isotope variations in the metallic elements. Biologically influenced and truly inorganic isotope fractionation processes have been demonstrated over the mass range of metals. This Elements issue provides an overview of the application of metal stable isotopes to low-temperature systems, which extend across the borders of several science disciplines: geology, hydrology, biology, environmental science, and biomedicine. Information on instrumentation, fractionation processes, data-reporting terminology, and reference materials presented here will help the reader to better understand this rapidly evolving field.
Categories: Publication;
Types: Citation;
Tags: Metals,
Sta,
isotope fractionation,
mass spectrometry
Diatom assemblages in sediments from two subalpine lakes in the Uinta Mountains, Utah, show asynchronous changes that are related to both anthropogenic and natural inputs of dust. These lakes are downwind of sources of atmospheric inputs originating from mining, industrial, urban, agricultural and natural sources that are distributed within tens to hundreds of kilometers west and south of the Uinta Mountains. Sediment cores were retrieved from Marshall and Hidden lakes to determine the impacts of atmospheric pollution, especially metals. Paleolimnological techniques, including elemental analyses and 210Pb and 239+240Pu dating, indicate that both lakes began receiving eolian inputs from anthropogenic sources in the...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Hydrobiologia,
Springer Netherlands,
alpine,
diatom,
dust,
This data set contains concentrations of phosphorus and 48 other elements determined on core samples collected in Lake Lanier.
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.), carbon, and particle size determination in Canyon Mine containment pond sediment samples collected in calendar year 2019.
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.) in Pinyon Plain Mine containment pond invertebrate samples collected in calendar year 2021.
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.), major anions (chloride, nitrite+nitrate as nitrogen, sulfate, etc.), organic carbon, and general water quality parameters in Pinyon Plain Mine containment pond water samples collected in calendar year 2022.
The overarching objective is to understand how anthropogenic sources of inorganic contaminants (metals) affect the structure and function of aquatic ecosystems. Elements of the research include: 1) develop and apply analytical methods and models to understand and predict metal bioavailability and bioaccumulation in aquatic organisms; 2) define effects of metal exposure on aquatic species; 3) communicate research findings to scientific and regulatory communities to support the management of water resources.
Categories: Project;
Tags: Aquatic Habitat,
Contaminants,
Ecology,
Estuaries and Near-Shore Environments,
Metals
The effects of elevated metals (dissolved Zn, Mn and/or Fe) in a Rocky Mountain stream were assessed using measures of primary productivity, community respiration and water-column toxicity. Primary productivity was measured as rates of O2 evolution from natural substrates incubated in situ in closed chambers. Oxygen depletion within these chambers, when incubated in the dark, provided estimates of periphyton community respiration. Sediment community respiration on fine-grained sediments, collected and composited along each stream study reach, was measured on-site by incubating these sediments in closed chambers and measuring O2 depletion. Toxicity was measured as percent mortality of Ceriodaphnia dubia during 48...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Ceriodaphnia toxicity,
Environmental Pollution,
benthic metabolism,
chambers,
metals
Particle-bound metal transport after removal of a small dam in the Pawtuxet River, Rhode Island, USA
The Pawtuxet River in Rhode Island, USA, has a long history of industrial activity and pollutant discharges. Metal contamination of the river sediments is well documented and historically exceeded toxicity thresholds for a variety of organisms. The Pawtuxet River dam, a low-head dam at the mouth of the river, was removed in August 2011. The removal of the dam was part of an effort to restore the riverine ecosystem after centuries of anthropogenic impact. Sediment traps were deployed below the dam to assess changes in metal concentrations and fluxes (Ag, Cd, Cr, Cu, Ni, Pb, and Zn) from the river system into Pawtuxet Cove. Sediment traps were deployed for an average duration of 24 days each, and deployments continued...
Categories: Publication;
Types: Citation;
Tags: *Environmental Monitoring,
*Power Plants,
Chemical/*analysis,
Dam removal,
Heavy/*analysis,
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.) in Canyon Mine containment pond vegetation samples collected in calendar year 2018, plus mercury in vegetation samples collected in 2017 and 2018.
Concentrations of 31 metals, metalloids, and other elements were measured in insects and insectivorous bird tissues from three drainages with different geochemistry and mining histories in Summit Co., Colorado, in 2003, 2004, and 2005. In insect samples, all 25 elements that were analyzed in all years increased in both Snake and Deer Creeks in the mining impacted areas compared to areas above and below the mining impacted areas. This distribution of elements was predicted from known or expected sediment contamination resulting from abandoned mine tailings in those drainages. Element concentrations in avian liver tissues were in concordance with levels in insects, that is with concentrations higher in mid-drainage...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado,
Environmental Monitoring and Assessment,
Summit County,
abandoned mine tailings,
insectivorous birds,
<p>The overall objective of my research is to understand the movement and quality of surface and groundwater using geochemical approaches. Some key issues that are considered in this research are the environmental aspects of energy and mineral resources, climate change, and carbon cycling and sequestration. The geochemical approaches that are used in this research include the use of isotopic tracers, trace elements, and radioisotopes. My research has focused on the sampling and analysis of produced waters from geologic carbon sequestration studies, geochemical characterization of sediment transport in the coastal zone, the environmental chemistry of mercury in coastal regions, and water quality analysis for samples...
General objectives are to 1) add to the fundamental understanding of Se biogeochemistry; 2) document Se sources and assess the environmental impacts of Se contamination; 3) construct and validate an ecosystem-scale Se methodology that connects dissolved Se to bioaccumulated Se within an occurrence of Se exposure; and 4) develop scenarios to illustrate ecosystem foodwebs and hydrologic settings that control Se exposure within a watershed or site as an ecologically consistent management approach for Se. Within that framework, the specific objectives are to 1) quantitatively apply ecosystem-scale Se modeling on a site-specific basis in support of fish and wildlife management or protection through collaboration with...
Geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) Mineral Resources Section conducted four weeks of helicopter-supported mapping and fieldwork from June 26 through July 24, 2013. The Styx River project in the Lime Hills C-1 Quadrangle was part of the State-funded Airborne Geophysical/Geological Mineral Inventory (AGGMI) program as part of the State's Strategic Minerals Assessment Project, an initiative designed to evaluate Alaska's potential for rare-earth elements, PGEs, and other similarly supply-challenged resources. The Styx River project area has active and ongoing mineral exploration for deposit types including porphyry copper/molybdenum/gold, reduced intrusion-related gold, and...
In 2016, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) and University of Alaska Fairbanks carried out a two-part geologic mapping and geochemical sampling project in the Tok River area of the Tanacross A-5 and A-6 quadrangles (June 12-26 and July 8-26). This report provides results of stream-sediment sampling for trace-element geochemistry. An initial suite of sediment samples was collected from streams draining known gold occurrences, including the Stibnite Creek and Noah prospects, and numerous prospects in the White Gold area. These samples were split in half and the two splits were sieved to -200 mesh and -80 mesh, respectively. The splits were then both analyzed to determine...
The State of Alaska's Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska's statewide potential for strategic and critical mineral resources. The SCM Assessment project is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For the geochemical part of the SCM Assessment project, thousands of geochemical-sample analyses and locations from historical U.S. Bureau of Mines (USBM), U.S. Geological Survey (USGS), Bureau of Land Management (BLM), DGGS, Alaska Territorial Department of Mines, Alaska Division of Mines and...
During the 2017 field season, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted geologic mapping and sampling of part of the Richardson Mining District southeast of Fairbanks, including parts of the Big Delta B-4, B-5, and C-5 quadrangles. The project area is about 30 miles west of the Pogo gold mine and covers the currently active Montecristo and Uncle Sam gold-exploration properties. The goal of DGGS's work in this area is to conduct a mineral-resource assessment and to build an improved understanding of the area's geology and controls on gold mineralization to facilitate industry exploration targeting. This report is based on 17 days of fieldwork completed June 23-July 3,...
|
|
