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Subaqueous volcaniclastic facies in the ancestral Cascades Arc in Southern Washington State—The Ohanapecosh Formation and Wildcat Creek Beds
report
posted on 2023-05-25, 18:53 authored by Martin JutzelerMartin Jutzeler, Jocelyn McPhieJocelyn McPhiePartly situated in the idyllic Mount Rainier National Park, this field trip visits exceptional examples of Oligocene subaqueous volcaniclastic successions in continental basins adjacent to the Ancestral Cascades arc. The >800-m-thick Ohanapecosh Formation (32–26 Ma) and the >300-m-thick Wildcat Creek (27 Ma) beds record similar sedimentation processes from various volcanic sources. Both show evidence of below wave-base deposition, and voluminous accumulation of volcaniclastic facies from subaqueous density currents and suspension settling. Eruption-fed facies include deposits from pyroclastic flows that crossed the shoreline, from tephra fallout over water, and from probable Surtseyan eruptions, whereas re-sedimented facies comprise subaqueous density currents and debris flow deposits.
History
Publication title
U.S. Geological Survey, Reston, Virginia: 2017Commissioning body
US Department of the Interior; US Geological SurveyVolume
Report 2017–5022–BPagination
32Department/School
School of Natural SciencesPublisher
US Department of the Interior; US Geological SurveyPlace of publication
United StatesRepository Status
- Restricted