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GEOREF RECORD

Basaltic volcanism of the central and western Snake River plain; a guide to field relations between Twin Falls and Mountain Home, Idaho

John W. Shervais, John D. Kauffman, Virginia S. Gillerman, Kurt L. Othberg, Scott K. Vetter, V. Ruth Hobson, Meghan Zarnetske, Matthew F. Cooke, Scott H. Matthews and Barry B. Hanan
Basaltic volcanism of the central and western Snake River plain; a guide to field relations between Twin Falls and Mountain Home, Idaho (in Interior western United States, Joel L. Pederson (editor) and Carol M. Dehler (editor))
Field Guide (Geological Society of America) (2005) 6: 27-52

Abstract

Basaltic volcanism in the Snake River Plain of southern Idaho has long been associated with the concept of a mantle plume that was overridden by North American during the Neogene and now resides beneath the Yellowstone plateau. This concept is consistent with the time-transgressive nature of rhyolite volcanism in the plain, but the history of basaltic volcanism is more complex. In the eastern Snake River Plain, basalts erupted after the end of major silicic volcanism. The basalts typically erupt from small shield volcanoes that cover up to 680 km (super 2) and may form elongate flows that extend 50-60 km from the central vent. The shields coalesce to form extensive plains of basalt that mantle the entire width of the plain, with the thickest accumulations of basalt forming an axial high along the length of the plain. In contrast, basaltic volcanism in the western Snake River Plain formed in two episodes: the first (ca. 7-9 Ma) immediately following the eruption of rhyolites laveas now exposed along the margins of the plain, and the second forming in the Pleistocene (< or =2 Ma), long after active volcanism ceased in the adjacent eastern Snake River Plain. Pleistocene basalts of the western Snake River Plain are intercalated with, or overlie, lacustrine sediments of Pliocene-Pleistocene Lake Idaho, basaltic volcanism. The contrast in occurrence and chemistry of basalt in the eastern and western plains suggest the interpretation of volcanism in the Snake River Plain is more nuanced than simple models proposed to date.


ISSN: 2333-0937
EISSN: 2333-0945
Serial Title: Field Guide (Geological Society of America)
Serial Volume: 6
Title: Basaltic volcanism of the central and western Snake River plain; a guide to field relations between Twin Falls and Mountain Home, Idaho
Title: Interior western United States
Affiliation: Utah State University, Department of Geology, Logan, UT, United States
Affiliation: Utah State University, Department of Geology, Logan, UT, United States
Pages: 27-52
Published: 2005
Text Language: English
Publisher: Geological Society of America, Boulder, CO, United States
ISBN: 0-8137-0006-X
References: 95
Accession Number: 2006-030399
Categories: Igneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sketch maps
N42°46'00" - N44°07'00", W116°17'60" - W114°58'60"
N42°00'00" - N42°49'60", W115°04'60" - W114°00'00"
Secondary Affiliation: University of Idaho, USA, United StatesBoise State University, USA, United StatesCentenary College, USA, United StatesUniversity of South Carolina, USA, United StatesSan Diego State University, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 200609
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