Eruption and emplacement of flood basalt: An example from the large-volume Teepee Butte Member, Columbia River Basalt Group

Research Article| December 01, 1992 Eruption and emplacement of flood basalt: An example from the large-volume Teepee Butte Member, Columbia River Basalt Group STEPHEN P. REIDEL; STEPHEN P. REIDEL 1Department of Geology, Washington State University, Pullman, Washington 99164 Search for other works by this author on: GSW Google Scholar TERRY L. TOLAN TERRY L. TOLAN 2Geology Department, Portland State University, P.O. 751, Portland, Oregon 97207 Search for other works by this author on: GSW Google Scholar Author and Article Information STEPHEN P. REIDEL 1Department of Geology, Washington State University, Pullman, Washington 99164 TERRY L. TOLAN 2Geology Department, Portland State University, P.O. 751, Portland, Oregon 97207 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1992) 104 (12): 1650–1671. https://doi.org/10.1130/0016-7606(1992)104<1650:EAEOFB>2.3.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 STEPHEN P. REIDEL, TERRY L. TOLAN; Eruption and emplacement of flood basalt: An example from the large-volume Teepee Butte Member, Columbia River Basalt Group. GSA Bulletin 1992;; 104 (12): 1650–1671. doi: https://doi.org/10.1130/0016-7606(1992)104<1650:EAEOFB>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 SocietyGSA Bulletin Search Advanced Search Abstract Flows of the Teepee Butte Member, Grande Ronde Basalt, issued from a vent system in southeastern Washington, northeastern Oregon, and western Idaho. Three distinct basalt flows were erupted: the Limekiln Rapids flow, the Joseph Creek flow, and the Pruitt Draw flow. Together these mappable flows cover more than 52,000 km2 and have a volume exceeding 5,000 km3.A portion of the vent system for the Joseph Creek flow is exposed in cross section in Joseph Canyon, Washington; it is one of the best preserved Columbia River Basalt Group vent complexes known. The vent complex is about 1 km in cross section, 30 m high, and composed of deposits characteristic of Hawaiian-type volcanism. The vent is asymmetrical; the eastern rampart consists of intercalated pyroclastic deposits and thin pahoehoe flows; the western rampart is composed wholly of pahoehoe flows. Vent deposits indicate a complex sequence of events accompanied by lava fountaining and deposition of tephra and spatter- fed flows. Deformation of the vent ramparts and breccia deposits in the vent complex suggest several lava rise/fall cycles that led to fissure widening by wall collapse. A lava pond formed in the fissure at the end of the eruptive activity.Flows of the Teepee Butte Member are compositionally homogeneous and were emplaced as sheet flows, each having several local flow units. Our study supports the importance of linear vent systems and the westward Palouse Slope, along with the large-volume lava flows, in controlling the distribution of Columbia River Basalt Group flows. Other factors, including the number of active fissure segments and topography, modified the shape of the flows and the number of flow units. 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.