Geochemical and Paleomagnetic Stratigraphy of the Picture Gorge and Yakima Basalts (Columbia River Group) in Central Oregon

Research Article| January 01, 1974 Geochemical and Paleomagnetic Stratigraphy of the Picture Gorge and Yakima Basalts (Columbia River Group) in Central Oregon SIMON NATHAN; SIMON NATHAN 1Center for Volcanology, University of Oregon, Eugene, Oregon 97403 Search for other works by this author on: GSW Google Scholar JONATHAN S. FRUCHTER JONATHAN S. FRUCHTER 1Center for Volcanology, University of Oregon, Eugene, Oregon 97403 Search for other works by this author on: GSW Google Scholar Author and Article Information SIMON NATHAN 1Center for Volcanology, University of Oregon, Eugene, Oregon 97403 JONATHAN S. FRUCHTER 1Center for Volcanology, University of Oregon, Eugene, Oregon 97403 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 (1): 63–76. https://doi.org/10.1130/0016-7606(1974)85<63:GAPSOT>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 SIMON NATHAN, JONATHAN S. FRUCHTER; Geochemical and Paleomagnetic Stratigraphy of the Picture Gorge and Yakima Basalts (Columbia River Group) in Central Oregon. GSA Bulletin 1974;; 85 (1): 63–76. doi: https://doi.org/10.1130/0016-7606(1974)85<63:GAPSOT>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 Trace- and major-element analyses and paleomagnetic measurements have been used in conjunction with field studies, mainly in central Oregon, to investigate the relation between the Picture Gorge and Yakima basalts as well as other more recently recognized basalt types in the Columbia River Group. Picture Gorge and Yakima basalts are rarely seen in contact, as they were separated at the time of eruption by the Blue Mountains anticline. Nearly all areas previously mapped as Yakima basalt on the south side of the anticline are in fact Picture Gorge basalt. Locally, however, a few flows of Picture Gorge basalt crossed the divide; in the Butte Creek area, Yakima and Picture Gorge flows are interbedded, thus providing a link for correlating the two units. Stratigraphic evidence thus suggests that the upper part of the Picture Gorge basalt was erupted at the same time as the lower part of the Yakima basalt.Miocene basalts in western Oregon have been compared with the Columbia River Group east of the Cascade Range. The main area mapped as Columbia River Group in the lower Willamette valley has the composition of Yakima basalt, but Miocene intrusions near Eugene and flows in the Sardine Formation are compositionally distinct from the chemical types recognized farther east. 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.