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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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To characterize eruption activity of the iconic Old Faithful Geyser in Yellowstone National Park over past centuries, we obtained 41 new radiocarbon dates of mineralized wood preserved in the mound of silica that precipitated from erupted waters. Trees do not grow on active geyser mounds, implying that trees grew on the Old Faithful Geyser mound during a protracted period of eruption quiescence. Rooted stumps and root crowns located on higher parts of the mound are evidence that at the time of tree growth, the geyser mound closely resembled its current appearance. The range of calibrated radiocarbon dates (1233–1362 CE) is coincident with a series of severe multidecadal regional droughts toward the end of the Medieval...
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In the past century, eruptions of Steamboat Geyser in Yellowstone’s Norris Geyser Basin were mainly clustered in three episodes: between 1961 and 1969, between 1982 and 1984, and in a sequence of eruptions that began in 2018 (Reed et al., 2021) and resulted in extensive damage to, and mortality of the surrounding trees. To characterize tree response to geyser activity over time, and the response of geyser activity to climate variability, aerial and ground imagery were analyzed to document changes in tree coverage around the geyser since 1954. Twenty samples of silicified tree remnants were collected from near the geyser vent for radiocarbon (14C) dating to determine if trees grew during periods when the geyser was...
Categories: Data;
Tags: Climatology,
Ecology,
Ecology,
Forestry,
Forestry, All tags...
Geyser,
Hydrology,
Hydrology,
Land Use Change,
Land Use Change,
Mineralization,
Paleoclimate,
Paleohydrology,
Radiocarbon,
USGS Science Data Catalog (SDC),
Volcanology,
Volcanology,
Wyoming,
Yellowstone National Park,
biota,
carbon-14 analysis, Fewer tags
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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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