Older andesite and intermediate flows and breccias (NVTa1;0)

Older andesite and intermediate flows and breccias

Unit includes andesite or dacite flows, flow breccias, and hypabyssal rocks in Lander County, andesitic to latitic flows, pyroclastic rocks, and phenoandesitic and phenolatitic flows in Elko County, and other undifferentiated volcanic rocks in other counties. Present in Humboldt, northern Nye, Churchill, Elko, Eureka, Lander, and White Pine Counties. It corresponds to the 1978 State map unit Ta1.

State	Nevada
Name	Older andesite and intermediate flows and breccias
Geologic age	lower Oligocene to middle Eocene
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Andesite (Flow, Volcaniclastic-volcanic breccia) Igneous > Volcanic > Felsic-volcanic > Dacite (Flow, Volcaniclastic-volcanic breccia) Minor Igneous > Hypabyssalhypabyssal rocks in Lander County Igneous > Volcanic > Felsic-volcanic > Latite (Flow, Pyroclastic)andesitic to latitic flows, pyroclastic rocks, and phenoandesitic and phenolatitic flows in Elko County Igneous > Volcanicother undifferentiated volcanic rocks in other counties
References	Crafford, A.E.J., 2007, Geologic Map of Nevada: U.S. Geological Survey Data Series 249, 1 CD-ROM, 46 p., 1 plate; Scale 1:250,000. Extended unit descriptions taken from pamphlet that accompanies geologic data/map. https://pubs.er.usgs.gov/publication/ds249
NGMDB product	NGMDB product page for 81584
Counties	Churchill - Elko - Eureka - Humboldt - Lander - Nye - White Pine

Older andesite and intermediate flows and breccias

Crafford, A.E.J., 2007, Geologic Map of Nevada: U.S. Geological Survey Data Series 249, 1 CD-ROM, 46 p., 1 plate; Scale 1:250,000. Extended unit descriptions taken from pamphlet that accompanies geologic data/map.