The Aurora-Bodie Volcanic Feld

US Forest Service Intermountain Region - Geology - Geologic Points of Interest - Humboldt-Toiyabe NF:

"The Aurora-Bodie volcanic field occurs east-northeast of Mono Lake, between the Sierra Nevada and the Great Basin. Calc-alkaline andesite, dacite and trachyandesite lavas, breccias and ashflow tuffs, dated 15 to 8 million years ago, underlie a tighter concentration of younger alkaline-calcic cinder cones and flows. The older volcanics cover approximately 80 square kilometers with a volume of approximately 35 cubic kilometers. Andesite domes and flows, 4.5 to 2 million years in age, occur at Cedar Hill and other areas in the field, and Pleistocene to late Holocene basaltic rocks forming well-preserved cinder cones and flows cover approximately 100 square kilometers. The probable late Pleistocene age Mud Springs volcano consists of a steep-fronted bulbous flow surrounding a depressed vent area, and a 7-kilometer-long ridged flow, together creating a remarkably distinctive landform. Although trees cover the flows, partially accounting for their dark color, the volcano is clearly one of the freshest in the Aurora-Bodie field.

Aurora Crater, approximately 12 kilometers west of Mud Springs volcano, is a 1.7-kilometer-wide breached crater of approximately 250,000 years, totally surrounded by lava flows, with an estimated total volume of 2 cubic kilometers. Many of the volcanoes are cut by faults, and Pleistocene basalt has been warped as well. The topography of the entire area has been softened by ash probably erupted by the younger Mono Craters to the southwest. Gold and silver found in quartz veins in the Miocene (but not younger) volcanic rocks were mined until about 1950, and only the ghost towns of Bodie, California, and Aurora, Nevada, remain. (From: Wood and Kienle, 1990)"