Age and composition of igneous rocks, Edna Mountain quadrangle, Humboldt County, Nevada

Journal of Research of the U.S. Geological Survey
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Abstract

Six pulses of igneous activity ranging in age from Jurassic to Pliocene have been identified in the Edna Mountain quadrangle, Humboldt County, Nev. Porphyritic syenite am! quartz monzonite of Jurassic age (146-164 million years) at Buffalo Mountain are highly potassic through a wide range in SiO2 content from olivine-bearing syenite to quartz-rich monzonite, and their composition contrasts sharply with plutons elsewhere in north-central Nevada. Granodiorite and quartz monzonite plutons of Cretaceous age (88- 106 m.y.) are chemically and mineralogically similar to other calc-alkaline plutons in north-central Nevada. Four episodes of Tertiary volcanism include rhyolite ashflow tuffs and slightly younger andesitic basalt flows and tuffs of Oligocene age, rhyolite vitrophyre of late Miocene age, and olivine basalt flows of Pliocene age. Their age and mineralogical and chemical compositions are similar to other Tertiary volcanic rocks in north-central Nevada.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Age and composition of igneous rocks, Edna Mountain quadrangle, Humboldt County, Nevada
Series title Journal of Research of the U.S. Geological Survey
Volume 6
Issue 6
Year Published 1978
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Description 17 p.
First page 727
Last page 743
Country United States
State Nevada
County Humboldt County
Other Geospatial Edna Mountain quadrangle
Online Only (Y/N) N
Additional Online Files (Y/N) N
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