Unified Interior Regions

This aerial view toward the south shows the northeastern side of Paoha Island in Mono Lake, California; the Mono Craters and Sierra Nevada are in the far distance. The north (bottom of photo) and east (left side of island) tips of the island consist of craters and lava flows that may have erupted as recently as A.D. 1720-1850.

This high aerial view of Negit Island is toward the southwest. Three separate vents each erupted individual dacite lava flows to form three parallel elongate flows. The vents are located on the highest parts of the flows. The northwest edge of Paoha Island is visible in upper left.

This outcrop is exposed in a rock quarry in Chalfant Valley about 25 km (15 mi) southwest of Long Valley Caldera. The two main units of the Bishop Tuff deposit are visible here: (1) the lower 5 m (16 f) of the section consists of the pumice that fell to the ground (airfall pumice) downwind from the eruption; and (2) the upper 5-6 m (16-20 f) of the section consists of the

Lava domes of the Mono-Inyo Craters volcanic chain.

Inyo Craters, part of the Mono-Inyo Chain, Long Valley region, California.

The breach in the rims of both Red Cones cinder cones occurred when lava poured through the breaches and spilled about 1.5 km (1 mi) down the east valley wall of the Middle Fork of the San Joaquin River (to the left of this image).

Hummocky terrain of the debris avalanche north of Mount Shasta.

First geothermal well drilled at Coso geothermal area, south-central California, by private industry. It, together with a few other wells, has been developed to feed steam into the initial powerplant. Photo from USGS Circular 1249.

Negit Island in Mono Lake, California viewed toward the NW. The three parallel dacite lava flows that form the island are clearly visible.

Mount Konocti, a mostly dacitic composite cone, on the western shore of Clear Lake, California. Thurston Lake is in the foreground.

Tremolite asbestos, Death Valley, California.