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Filters: Tags: hydrothermal processes (X) > partyWithName: Shaul Hurwitz (X)

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Radiocarbon dating of silicified wood was performed at the U.S. Geological Survey’s Radiocarbon Laboratory in Denver, Colorado. All samples were chemically treated using the standard acid-base-acid (ABA) procedure before being combusted online in the presence of excess high-purity oxygen. Water and other contaminant gases were removed using cryogenic separation techniques, and the resulting purified CO2 gas was measured manometrically and converted to graphite using an iron catalyst and hydrogen reduction (Vogel et al., 1984). Graphite targets were then submitted for accelerator mass spectrometry 14C analysis at the National Ocean Sciences Accelerator Mass Spectrometry facility in Woods Hole, Massachusetts. All...
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Silicified wood samples were vacuum impregnated with epoxy, sectioned, and sputter coated with 10 nm Au/Pd at the U.S. Geological Survey, Menlo Park, CA. Samples were imaged in a Tescan VEGA3 Scanning Electron Microscope (SEM) equipped with an Oxford 150 mm2 X-MaxN large area energy dispersive spectrometer at the U.S. Geological Survey, Menlo Park, CA. Backscatter (BSE) images were collected with an accelerating voltage (HV) of 30 kV and a working distance (WD) of ~15 mm. Magnification is indicated on individual images. The data files for Scanning Electron Microsocopy (SEM) contain representative SEM-BSE images of samples OFL101 and OFL103-2. This research was conducted under Yellowstone Research Permit YELL-SCI-8030.
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Old Faithful Geyser in the Upper Geyser Basin of Yellowstone National Park is one of the best studied geysers in the world. Under research permit YELL-SCI-8030, samples from 13 silicified tree remnants were collected adjacent to the Old Faithful Geyser cone in April and November 2019. The silicified wood samples were dated using the radiocarbon (14C) method and were analyzed by scanning electron microscope (SEM) to determine the extent of wood silicification. This study was conducted in order to provide new information on the geyser’s past decadal to centennial eruptive activity. Understanding Old Faithful’s past could provide a baseline for understanding future changes in its eruption intervals.
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Hot Creek Gorge contains the most obvious surface expression of the hydrothermal system in Long Valley Caldera, California, discharging 200-300 L/s of thermal water according to USGS measurements made since 1988. Formerly, Hot Creek was a popular public swimming area, but it was closed in 2006 due to unpredictable temperature fluctuations and sporadic geysering of thermal water within the creek (Evans et al., 2018). The USGS has monitored the thermal regime in the area since the mid-1980s, including a series of long-term studies 0.6 km away at well CH-10b. Temperature measurements in the ~100 m deep well, which have been performed on an intermittent basis since it was drilled in 1983, reveal a complex temperature...
    map background search result map search result map Groundwater levels and temperatures in well CH-10b near Hot Creek, Long Valley Caldera, eastern California (ver. 2.0, May 2020) Silicified wood from around Old Faithful Geyser, Yellowstone National Park Radiocarbon Dating Scanning Electron Microscopy (SEM) Radiocarbon Dating Scanning Electron Microscopy (SEM) Silicified wood from around Old Faithful Geyser, Yellowstone National Park Groundwater levels and temperatures in well CH-10b near Hot Creek, Long Valley Caldera, eastern California (ver. 2.0, May 2020)