Hydrothermal mineralogy studies of specimens collected from nine geothermal drill holes suggest that, at the locations and depths drilled, past temperatures have been hottest (exceeding 300?C) near ring fractures on the south and west sides of Newberry Volcano.
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Hydrothermal mineralogy of core from geothermal drill holes at Newberry Volcano, Oregon
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U.S. Dept. of the Interior, U.S. Geological Survey ;
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