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Note: No formal accuracy tests were conducted and these data are disseminated to allow discussion related to methods. Sample Analyses: Samples were processed at both the USGS in Menlo Park, CA, and at UC Berkeley following established methodology for separating organic material from sinter (Howald et al., 2014; Lowenstern et al., 2016; Slagter et al., 2019). First, the exterior surface of each sample was removed using a rock saw, and then any further material was removed if there was any visible algal material in the interior of the sample. Second, samples underwent a series of chemical baths. Samples were crushed and soaked in 30% hydrogen peroxide for 48 hours to remove any remaining modern algae. Once cleaned,...
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Sample Analyses: Thin sections made at UC Berkeley were brought to the USGS, Menlo Park, CA and were coated with 25 nm carbon. Samples were analyzed at the USGS in Menlo Park, CA in a Tescan VEGA3 Scanning Electron Microscope (SEM) equipped with an Oxford 50 mm2 X-MaxN energy dispersive spectrometer. Thin sections were imaged with backscatter electrons. Energy dispersive X-ray spectroscopy (EDS) analyses and images were collected with an accelerating voltage of 15 kV and a working distance of 15 mm. Database Contents: The data files for “Energy Dispersive X-ray Spectroscopy (EDS) Data” contain representative element spectra analyses of samples UGB-TD-28, -30, -31, -32, -33, -36.
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Sample Analyses: Samples were analyzed for major and trace element concentrations of the unreacted and reacted sinter using a Thermo ARL Perform’X X-ray fluorescence (XRF) spectrometer at the Hamilton Analytical Laboratory at Hamilton College, New York, following protocols described in Johnson et al. (1999). One-part powdered sample is mixed with 2 parts Li-tetraborate flux and fused at 1000 °C in graphite crucibles. The cooled wavelength dispersive XRF (WDXRF) pellets are re-ground to powder and re-fused at the same temperature. Flat analytical surfaces are ground on steel-backed diamond laps. XRF determinations of 44 element concentrations are calibrated with approximately 70 reference materials. Net peak intensities...
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Chemical changes in hot springs, as recorded by thermal waters and their mineral deposits, provide a window into the evolution of Yellowstone’s postglacial hydrothermal system. Travertine precipitated from thermal waters provide a record of chemical changes through time because they can be dated using U-series disequilibrium geochronology. These temporal data, along with measured radiogenic 87Sr/86Sr and stable isotope (carbon and oxygen) compositions and elemental concentrations, allow for the investigation of changes in hydrothermal system chemistry over time. This data release contains analyses conducted on samples of hydrothermal travertine collected from Upper and Lower Geyser Basins and near Madison Junction...
Categories: Data;
Tags: Climatology,
Geochemistry,
Hydrology,
Travertine,
U-Th disequilibrium dating, All tags...
USGS Science Data Catalog (SDC),
Volcanology,
Yellowstone National Park,
carbon isotopes,
elemental concentrations,
geoscientificInformation,
isotope geochemistry,
mineralogy,
oxygen isotopes,
strontium isotopes, Fewer tags
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Sample Analysis: Cation concentration data was obtained as a part of the beryllium isotope analyses. Samples collected from the Upper Geyser Basin were first treated in clean laboratory facilities at the University of New Hampshire following the methods laid out in the “Beryllium Isotope Data” portion of this data release. Following the hydrofluoric acid (HF) etches, and prior to Accelerated Mass Spectroscopy (AMS) analyses of 10Be, opal purity was assessed by measurement of major cation concentrations via inductively coupled plasma-optical emission spectrometry (ICP-OES) using a Perkin Elmer Optima 3300DV at the Analytical and Technical Services lab at SUNY College of Environmental Science and Forestry in Syracuse,...
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