Detailed mapping and geochemical analysis of Oligocene to early
Pliocene volcanic rocks in the Little Walker volcanic center, Mono
County, California have revealed a complex eruptive history. After
eruption of widespread rhyolitic ash flows of the Valley Springs
Formation in the Oligocene, Miocene to early Pliocene volcanism of
The Seaman Gulch area is located approximately 20
miles east of Redding, California and is part of the
eastern Klamath lithotectonic belt.
Rock units of the area are chiefly mafic and silicic
volcanics of island arc affinity and shale that are Permian
to Triassic in age. Volcanic rocks of Tertiary...
Surface and subsurface mapping are combined to determine the
geologic history along the San Gabriel fault near the town of Castaic.
Palomas Gneiss, Whitaker Granodiorite, and Pelona Schist are basement
terranes encountered in the subsurface. West of the San
Gabriel fault, basement is unconformably overlain by marine middle