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dc.contributor.advisor Rogers, John J. W.
dc.creatorLeeman, William Prescott
dc.date.accessioned 2016-04-22T21:59:10Z
dc.date.available 2016-04-22T21:59:10Z
dc.date.issued 1969
dc.identifier.citation Leeman, William Prescott. "Late Cenozoic basalts from the Basin-Range province, western United States." (1969) Master’s Thesis, Rice University. https://hdl.handle.net/1911/89961.
dc.identifier.urihttps://hdl.handle.net/1911/89961
dc.description.abstract Petrographic and chemical analyses demonstrate that late Cenozoic mafic lavas from the Basin-Range province, western United States, are predominantly alkali-olivine basalts. Associated with these lavas are lesser volumes of basaltic andesite which appear to be differentiates from the more primitive alkali basalts. Late Cenozoic basalts from adjacent regions (Columbia River Plateau, Snake River Plain, Yellowstone area, High Cascades and Sierra Nevada) are predominantly tholeiitic. This apparent petrologic provincialism is supported by complementary variations in heat flow, seismic velocities, crustal thickness, magnetic anomalies and geologic setting. Alkali-olivine basalts from Japan and eastern Australia are analogous to those from the Basin-Range province both in composition and tectonic environment. It is suggested that these lavas are the products of a unique environment characterized by high heat flow and a thin crust. Recent melting experiments on peridotites and basalts and measurements of heat flow allow limits to be placed on the depth of origin of Basin-Range alkali-olivine basalt magmas. It is proposed that these lavas are produced by partial melting (less than 20%) of peridotitic mantle material at depths between 40 and 60 km in response to an elevated geothermal gradient. The basaltic andesites may be derived from hydrous alkali basalt magma by fractionation at depths of 30 to 40 km.
dc.format.extent 88 pp
dc.language.iso eng
dc.title Late Cenozoic basalts from the Basin-Range province, western United States
dc.identifier.digital RICE0996
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Earth Science
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Masters
thesis.degree.name Master of Arts
dc.format.digitalOrigin reformatted digital
dc.identifier.callno Thesis Geol. 1969 Leeman


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