Late Cenzoic rhyolites from the Kern Plateau, southern Sierra Nevada, California.

American Journal of Science
By:  and 

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Abstract

Four late Cenozoic rhyolite domes lie atop the Kern Plateau, 30 to 40km S-SE of Mount Whitney. K-Ar and 40Ar/39Ar dating shows that Monache, Templeton, and Little Templeton Mountains are all about 2.4Ma old; a small dome nearby is approx 0.2Ma old. The three older rhyolites have SiO2 = 73-74% and have steep, fractionated rare earth element (REE) patterns; the youngest has SiO2 = 76% and a concave-upward REE pattern with a large negative Eu anomaly, Monache rhyolite contains the unusual phenocryst assemblage almandine + fayalite + biotite + oligoclase. The 2.4Ma old rocks may be nearly unmodified partial melts of crustal sources, whereas the 0.2Ma old rhyolite may be a product of relatively shallow differentiation. The rhyolites and nearby basalts are coeval with mafic and silicic volcanic rocks in the Coso Range about 40km to the SE. Their generation and eruption may reflect intense tectonic extension at the margin of the Basin and Range province and concomitant relaxation of compressive stress in a W- NW direction, allowing melts to reach the surface in the adjacent Sierra Nevada.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Late Cenzoic rhyolites from the Kern Plateau, southern Sierra Nevada, California.
Series title American Journal of Science
DOI 10.2475/ajs.281.1.1
Volume 281
Issue 1
Year Published 1981
Language English
Publisher American Journal of Science
Contributing office(s) Volcano Science Center
Description 34 p.
First page 1
Last page 34
Country United States
State California
Other Geospatial Kern Plateau