Early Paleozoic magmatic events in the eastern Klamath Mountains, northern California

Abstract

Research Article| February 01, 1988 Early Paleozoic magmatic events in the eastern Klamath Mountains, northern California E. Timothy Wallin; E. Timothy Wallin 1Department of Geology, University of Kansas, Lawrence, Kansas 66045 Search for other works by this author on: GSW Google Scholar James M. Mattinson; James M. Mattinson 2Department of Geological Sciences, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar A. W. Potter A. W. Potter 3Department of Geology, Oregon State University, Corvallis, Oregon 97331 Search for other works by this author on: GSW Google Scholar Author and Article Information E. Timothy Wallin 1Department of Geology, University of Kansas, Lawrence, Kansas 66045 James M. Mattinson 2Department of Geological Sciences, University of California, Santa Barbara, California 93106 A. W. Potter 3Department of Geology, Oregon State University, Corvallis, Oregon 97331 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1988) 16 (2): 144–148. https://doi.org/10.1130/0091-7613(1988)016<0144:EPMEIT>2.3.CO;2 Article history First Online: 02 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 E. Timothy Wallin, James M. Mattinson, A. W. Potter; Early Paleozoic magmatic events in the eastern Klamath Mountains, northern California. Geology 1988;; 16 (2): 144–148. doi: https://doi.org/10.1130/0091-7613(1988)016<0144:EPMEIT>2.3.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 New U-Pb zircon ages for nine samples of tonalite and pegmatitic trondhjemite from the Trinity ophiolite and associated melange reveal a complex history of magmatic activity extending back into the earliest Cambrian, much older than previously believed. Earlier investigations, based on limited data, recognized lower Paleozoic crustal elements in the eastern Klamath terrane (EKT) ranging in age from Middle Ordovician to Early to Middle Devonian. The new work in the Yreka-Callahan area of the EKT confirms the Ordovician (440-475 Ma) and younger ages, but reveals for the first time the presence of tonalitic rocks that crystallized during a narrow time interval at about 565-570 Ma. We also recognize younger, Late Silurian magmatism at 412 Ma. In the context of available mapping, these ages indicate that the Trinity ophiolite is broadly polygenetic because parts of it yield crystallization ages that span approximately 150 m.y. Superjacent dismembered units of probable early Paleozoic age may be tectonostratigraphically equivalent to the Sierra City melange in the northern Sierra Nevada. 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.