Isotopic evidence on the structure and origin of subcontinental lithospheric mantle in southern Nevada

Journal Article · Sat Jun 10 04:00:00 EDT 1989 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB094iB06p07885· OSTI ID:5994398

Farmer, G L; Perry, F V; Semken, S; Crowe, B; Curtis, D; DePaolo, D J

The trace element and Nd, Sr, and Pb isotopic compositions of extension-related late Cenozoic basalts in southern Nevada were determined in order to constrain models for the tectonic evolution of the subcrustal mantle in the southern Great Basin since 10 Ma. Basalts in southern Nevada between latitudes 36/degree/N and 37/degree/N have low /var epsilon//sub Nd/(/minus/8 to /minus/10), high /Delta/8/4(+70 to +107) and /Delta/7/4 (+8 to +12), high /sup 87/Sr//sup 86/Sr, and low high field strength element (HFSE) concentrations relative to other Basin and Range basalts. Basalts with these chemical and isotopic traits have erupted semicontinuously in southern Nevada since 10 Ma. During the same period of time, basalts in central Nevada and east central California have shifted toward higher /var epsilon//sub Nd/, lower /sup 87/Sr//sup 86/Sr, lower /Delta/8/4 and /Delta/7/4, and higher HFSE contents than observed for the southern Nevada basalts.

• Research Organization: Department of Geological Sciences and Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder(US); Los Alamos National Laboratory, New Mexico; Navajo Community College, Shiprock, New Mexico; Los Alamos National Laboratory, New Mexico; Department of Geology and Geophysics, University of California, Berkeley
• OSTI ID: 5994398
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 94:B6; ISSN JGREA
• Country of Publication: United States
• Language: English

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58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
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FEDERAL REGION IX
GREAT BASIN
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