Petrologic character of Permian and Triassic greenstones from the Melange terrane of eastern Oregon and their implications for terrane origin

Abstract

Research Article| February 01, 1985 Petrologic character of Permian and Triassic greenstones from the Melange terrane of eastern Oregon and their implications for terrane origin Ellen D. Mullen Ellen D. Mullen 1Department of Geology, University of Arkansas, Fayetteville, Arkansas 72701 Search for other works by this author on: GSW Google Scholar Author and Article Information Ellen D. Mullen 1Department of Geology, University of Arkansas, Fayetteville, Arkansas 72701 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1985) 13 (2): 131–134. https://doi.org/10.1130/0091-7613(1985)13<131:PCOPAT>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Ellen D. Mullen; Petrologic character of Permian and Triassic greenstones from the Melange terrane of eastern Oregon and their implications for terrane origin. Geology 1985;; 13 (2): 131–134. doi: https://doi.org/10.1130/0091-7613(1985)13<131:PCOPAT>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 Petrography, mineralogy, and geochemistry of lower greenschist fades Permian and Triassic metavolcanics from throughout the pre-Tertiary Melange terrane of eastern Oregon indicate three different sources for these rocks: island arc, alkalic–within plate, and ocean ridge. Most have island-arc affinities. Metabasalts associated with chert at two widely separated localities have nearly identical alkalic compositions. Knockers in serpentinite-matrix melange have diverse sources. Metagabbros of the melange are mostly tholeiitic and may have an origin different from that of the calc-alkaline, arc-related, coherent ophiolite within the terrane. The compositions and lithologies of metavolcanics and metagabbros, as well as the associated metasediments, suggest that the Melange terrane represents a forearc. This content is PDF only. Please click on the PDF icon to access. 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.