Sedimentary record of subduction to forearc transition in the rotated Eocene basin of western Oregon

Research Article| July 01, 1983 Sedimentary record of subduction to forearc transition in the rotated Eocene basin of western Oregon Paul L. Heller; Paul L. Heller 1Laboratory of Geotectonics, Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Paul T. Ryberg Paul T. Ryberg 1Laboratory of Geotectonics, Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Author and Article Information Paul L. Heller 1Laboratory of Geotectonics, Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Paul T. Ryberg 1Laboratory of Geotectonics, Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1983) 11 (7): 380–383. https://doi.org/10.1130/0091-7613(1983)11<380:SROSTF>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Paul L. Heller, Paul T. Ryberg; Sedimentary record of subduction to forearc transition in the rotated Eocene basin of western Oregon. Geology 1983;; 11 (7): 380–383. doi: https://doi.org/10.1130/0091-7613(1983)11<380:SROSTF>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Systematic changes in compositions of Eocene sandstones in the southern part of the Oregon Coast Range constrain proposed models of tectonic accretion and rotation of this crustal fragment. Three basic petrofacies of lithic, arkosic, and volcanolithic composition can be defined sequentially from the base to the top of the section. The lithic petrofacies was deposited prior to rotation and was derived from the nearby Klamath Mountains during collision of the subjacent seamount terrane. The transition to arkosic composition coincided with the end of collision and the initiation of forearc basin subsidence. The arkosic sands contain muscovite and potassium feldspar derived from a continental-plutonic source area; their presence in the forearc sequence suggests that the Coast Range block lay farther to the east and closer to interior parts of the Mesozoic batholith belt prior to tectonic rotation. Volcanolithic sandstones were deposited after rotation of the Coast Range had begun, and they mark the beginning of volcanic activity in the adjacent Cascade arc. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.