Geochemistry and Tectonics of the Crescent Volcanic Rocks, Olympic Peninsula, Washington

Research Article| May 01, 1974 Geochemistry and Tectonics of the Crescent Volcanic Rocks, Olympic Peninsula, Washington WILLIAM GLASSLEY WILLIAM GLASSLEY 1Department of Geological Sciences, University of Washington, Seattle, Washington 98105 Search for other works by this author on: GSW Google Scholar Author and Article Information WILLIAM GLASSLEY 1Department of Geological Sciences, University of Washington, Seattle, Washington 98105 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1974) 85 (5): 785–794. https://doi.org/10.1130/0016-7606(1974)85<785:GATOTC>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 WILLIAM GLASSLEY; Geochemistry and Tectonics of the Crescent Volcanic Rocks, Olympic Peninsula, Washington. GSA Bulletin 1974;; 85 (5): 785–794. doi: https://doi.org/10.1130/0016-7606(1974)85<785:GATOTC>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 SocietyGSA Bulletin Search Advanced Search Abstract Major- and trace- element analyses of samples from the upper and lower members of the Crescent Formation demonstrate that these volcanic rocks are dominated by tholeiitic compositions, with minor amounts of alkali basalt also present. Basalt flows from both members have undergone little differentiation, and are compositionally similar. Differences in TiO2 and REE contents demonstrate, however, that these members are geochemically distinguishable. Lower-member tholeiites are identical to ridge tholeiites and are interpreted as representing a slice of oceanic upper crust. The upper member is similar to oceanic island basalts, but its primary tectonic significance is uncertain. It is postulated that the lower member was generated at a mid-ocean ridge and was subsequently subducted to a shallow level. Miocene uplift then juxtaposed the upper and lower members. 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.