Filters: Tags: isotope geochemistry (X)12 results (46ms)
Chemical and isotopic composition of produced waters from the lower Eagle Ford Group, south-central Texas
This dataset contains chemical and isotopic data from 39 produced water samples collected from sealed separators containing water from horizontal hydrocarbon wells in the lower Eagle Ford Group. The samples were collected from Lavaca and Gonzales counties, Texas in December, 2015. All wells had been in production for longer than 6 months and had produced more than 10,000 barrels (~160,000 liters) of water.
Hydrogen stable isotope data for: 'Mechanisms associated with an advance in the timing of seasonal reproduction in an urban songbird'.
This dataset includes stable hydrogen isotope values of the nonexchangeable hydrogen contained in the outer most secondary feathers of dark-eyed juncos (Junco hyemalis thurberi) collected from the University of California San Diego campus in La Jolla, California in 2014. Hydrogen isotope values in feathers have become a powerful tool for inferring the breeding grounds of a wide variety of avian species. In most of these migratory species, feathers are molted prior to departing the breeding grounds for more overwintering regions to the south. These data were used in tandem with morphological and genetic data for the classification of resident and migrant birds. There are two files in this dataset: 1) A tab delimitated...
Stable carbon and oxygen isotope paleoclimate records of U.S. Geological Survey-collected samples from Devils Hole and Devils Hole Cave 2, Nevada
In support of paleoclimatology investigations, samples of mammillary calcite, calcitic folia, and flowstone were collected by the U.S. Geological Survey in Devils Hole and Devils Hole Cave 2, Nevada, between 1983 and 1996. These samples came from about 60 m below to 9 m above the modern water table in these caverns. To determine δ18O and δ13C time series spanning the interval 567.7–4.5 ka, more than a thousand samples were milled and analyzed for their δ18O and δ13C values. To determine time-series ages, more than a hundred samples were analyzed using uranium-series dating. Many of these measurement results have not been published. Herein, we provide previously unpublished δ13C and δ18O values, and we provide unpublished...
Uranium-, thorium-, strontium-, carbon- and oxygen-isotope data used to evaluate a 300,000-year history of water-table fluctuations at Wind Cave, South Dakota, USA — scale, timing, and groundwater mixing in the Madison Aquifer
Tables of U- and Th-isotopic data used to calculate uranium-series age estimates and initial 234U/238U activity ratios as well as 87Sr/86Sr, δ13C, and δ18O for samples of phreatic speleothems from Wind Cave National Park and U- and Sr-isotopic compositions of waters from the southern Black Hills of South Dakota, USA
Uranium- and thorium-isotope data used to estimate uranium-series ages of Pleistocene lake deposits in the Lake Manix basin, Mojave Desert, California
This data release contains numerical U- and Th-isotopic data used to calculate uranium-series age estimates and initial 234U/238U activity ratios for samples of carbonate-rich clast coatings, oncoidal tufa rinds, calcite-replaced rhizoliths, carbonate nodules, and ostracod shells from sites associated with different lake levels of paleo Lake Manix near Barsow, CA. In addition, measured U concentrations and 234U/238U activity ratios for modern streamflow in the Mojave River and shallow groundwater from wells along the course of the Mojave River and nearby vicinity are included to help define the uranium-isotope composition of water that likely supplied paleolakes. Electronic data included herein support age interpretations...
Geochemical and isotopic compositions of stream sediment, parent rock, and nearshore sediment from southwest Puerto Rico, April 2017-June 2018
Geochemical and isotopic compositions were determined in stream sediment and parent rocks collected in April 2017 and June 2017 and in nearshore sediment collected bimonthly in sediment traps from May 2017 to June 2018 in the coastal zone and 12 drainages of southwest Puerto Rico: Rio Loco, Yauco, Guayanilla, Macana, Tallaboa, Matilde, Portugues, Bucana, Inabon, Jacaquas, Descalabrado, and Coamo. Geochemical compositional data include: a) total contents of major, minor, trace, and rare earth elements in the <0.063 mm-diameter fraction of terrestrial (n=53) and nearshore sediment (n=63) and powdered rocks (n=19) analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and inductively coupled...
Stable carbon and nitrogen isotope data for Siberian barn swallow subspecies collected during the breeding season
This dataset includes stable carbon and nitrogen isotope values for the inner tail retrices of three subspecies of barn swallow (Hirundo rustica rustica, H. r. tytleri, and H. r. gutturalis). Sampling was conducted in Russia (summer 2013), China (summer 2014), Mongolia (summer 2014), Japan (summer 2014), and western China (summer 2015) using mist nets. Stable carbon and nitrogen isotope data are useful proxies for diet and at broad spatial scales have the potential to constrain geographic distributions at the sub-population level. These data were used in tandem with molecular genetics to explore the extent to which a migratory divide explains the strength of reproductive isolation. There are two files in this dataset:...
Comparison of methane concentration and stable carbon isotope data for natural samples analyzed by discrete sample introduction module - cavity ring down spectroscopy (DSIM-CRDS) and traditional methods
A discrete sample introduction module (DSIM) was developed and interfaced to a cavity ring-down spectrometer to enable measurements of methane and CO2 concentrations and 13C values with a commercially available cavity ring-down spectrometer (CRDS). The DSIM-CRDS system permits the analysis of limited volume (5 - 100-ml) samples ranging six orders-of-magnitude from 100% analyte to the lower limit of instrument detection (2 ppm). We demonstrate system performance for methane by comparing concentrations and 13C results obtained by the DSIM and traditional methods for a variety of sample types, including low concentration (nanomolar) seawater and high concentration (> 90%) natural gas. The expansive concentration range...
Sr-, U-, H- and O-isotope data used to evaluate water sources in the Potrero Creek Wetlands, Upper Santa Cruz Basin, southern Arizona, USA
This data release includes a table of 87Sr/86Sr, 234U/238U, δ2H, and δ18O isotope data used to evaluate groundwater- and surface-water-sources contributing to water in perennial wetlands near the mouth of Potrero Creek within the Upper Santa Cruz Basin near Nogales, AZ. Interpretations of those data are discussed in the pamphlet accompanying the USGS Scientific Investigations Map SIM-XXXXX
The Southwest Isotope Research Laboratory (SWIRL) comprises a group of isotope geochemistry laboratories housed at the USGS in Denver. Capabilities include stable isotopes, radiogenic isotopes (TIMS and ICP-MS), noble gas isotopes, and 40Ar/39Ar geochronology. SWIRL scientists collaborate on a range of projects both inside and outside the USGS, including minerals, energy, geologic mapping, hydrology, biology and ecosystems, chronology, tracers, and environmental work.
Geochemistry of sediment and organic matter in drainages burned by the Altas and Nuns wildfires in October 2017 and of nearshore seabed sediment in north San Francisco Bay from March to April 2018
Fine-grained sediment was collected from the banks of Napa River, Sonoma Creek, and tributaries in March 2018 and from shallow nearshore areas of the northern reach of San Francisco Bay in April 2018. Bulk sediment was dated using activities of short-lived cosmogenic radionuclides (beryllium-7, cesium-137, and lead-210). Contents of potentially toxic metals and source-rock-indicative elements, including rare earth elements, were quantified in the fine fraction of sediment (particles less than 0.063 mm diameter). Ratios of stable carbon-13/carbon-12 isotopes and total carbon to total nitrogen were determined in sedimentary organic matter.
Stable carbon and nitrogen isotope data for the tissues and parasites of California sea lions and ice seals from California and Alaska coastal waters, collected 2009-2010 respectively
This dataset includes stable carbon and nitrogen isotope values for the tissues and parasites of California sea lions and ice seals from California and Alaska coastal waters necropsied and harvested in 2009-2010 respectively. Stable carbon and nitrogen isotope data are useful for clarifying trophic relationships in host-parasite systems. These data were used in tandem with tissue mercury concentrations to explore the role of gastrointestinal parasites on pinniped mercury exposure. There are two files in this dataset: 1) A comma delimited machine-readable file (*.csv) that represents the data dictionary, and 2) a comma delimited machine-readable file (*.csv) containing the data.