Filters: Tags: geochemistry (X)11,504 results (165ms)
Geochemistry has contributed significantly to the understanding of ground-water systems over the last 50 years. Historic advances include development of the hydrochemical facies concept, application of equilibrium theory, investigation of redox processes, and radiocarbon dating. Other hydrochemical concepts, tools, and techniques have helped elucidate mechanisms of flow and transport in ground-water systems, and have helped unlock an archive of paleoenvironmental information. Hydrochemical and isotopic information can be used to interpret the origin and mode of ground-water recharge, refine estimates of time scales of recharge and ground-water flow, decipher reactive processes, provide paleohydrological information,...
The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer
We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1) the uncontaminated zone above the sewage plume [350 µM dissolved oxygen (DO), pH 5.9]; (2) the suboxic zone (5 µM DO, pH 6.2, elevated concentrations of sewage-derived phosphate and nitrate); and (3) the anoxic zone [dissolved iron(II) 100–300 µM, pH 6.5–6.9, elevated concentrations of sewage-derived phosphate]. Sediments are comprised of greater than 90% quartz but the surfaces of quartz and other mineral grains are...
This is a report of geochemical data from various media collected on Isle Royale, a large island in northeastern Lake Superior. Isle Royale became a national park in 1940 and was designated as a wilderness area in 1976.USGS sampling began in 1996 as part of a larger project on the Midcontinent Rift in the Lake Superior region. Data are given in nine Microsoft Excel spreadsheets. All the data are newly acquired by the USGS.
Species and geochemical characteristics of heavy metals in the sediments of Kangjiaxi River in the Shuikoushan Mine Area, China
Utilizing geochemical, hydrologic, and boron isotopic data to assess the success of a salinity and selenium remediation project, Upper Colorado River Basin, Utah.
Stream discharge and geochemical data were collected at two sites along lower Ashley Creek, Utah, from 1999 to 2003, to assess the success of a site specific salinity and Se remediation project. The remediation project involved the replacement of a leaking sewage lagoon system that was interacting with Mancos Shale and increasing the dissolved salinity and Se load in Ashley Creek. Regression modeling successfully simulated the mean daily dissolved salinity and Se loads (R(2) values ranging from 0.82 to 0.97) at both the upstream (AC1) and downstream (AC2/AC2A) sites during the study period. Prior to lagoon closure, net gain in dissolved-salinity load exceeded 2177 metric tons/month and decreased after remediation...
This dataset contains geochemical data for unconsolidated sediments (stream sediments, lake sediments, etc.) collected by U.S. Geological Survey (USGS) personnel and analyzed in the analytical laboratories of the Geologic Division of the USGS. These data represent analyses of sediment samples collected in support of various USGS programs. The data were originally entered into the in-house Rock Analysis Storage System (RASS) database which was used by the Geologic Division from the early-1970's through the late-1980's to archive geochemical data. An unpublished CD-ROM was developed in 1996 that contains the RASS data in GSSEARCH format. That CD was used to generate this data set.
Geochemical evidence of pollutants from coal-fired generating stations in late pleistocene palaeosols in the Dalijia Shan, northwestern China
Biogeochemical influences on the determination of water chemistry in a temperate forest basin: Factors determining the pH value
This digital geologic map summarizes all available geologic information for the Tetilla Peak quadrangle located immediately southwest of Santa Fe, New Mexico. The geologic map consists of new polygon (geologic map units) and line (contact, fault, fold axis, dike, flow contact, hachure) data, as well as point data (locations for structural measurements, geochemical and geochronologic data, geophysical soundings, and water wells). The map database has been generated at 1:24,000 scale, and provides significant new geologic information for an area of the southern Cerros del Rio volcanic field, which sits astride the boundary of the Espanola and Santo Domingo basins of the Rio Grande rift.The quadrangle includes the...
Geochemical controls on peatland pore water from the Hudson Bay Lowland: A multivariate statistical approach
Ecological situation in the Russian part of the Black Sea -- isotopic-geochemical monitoring in a shore-sea system