CalVO geologist Mae Marcaida examines thin layers of volcanic ash sandwiched between thick beds of sediment deposited by ancestral Mono Lake in eastern California. Each ash layer is evidence of a past explosive eruption of the Mono Craters, which began erupting about 65,000 years ago just south of present-day Mono Lake.
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CalVO geologist Mae Marcaida examines thin layers of volcanic ash s...
CalVO geologist Mae Marcaida examines thin layers of volcanic ash sandwiched between thick beds of sediment deposited by ancestral Mono Lake in eastern California. Each ash layer is evidence of a past explosive eruption of the Mono Craters, which began erupting about 65,000 years ago just south of present-day Mono Lake.

Hot Spring Cove, Paoha Island, Mono Lake Volcanic Field
Hot Spring Cove, Paoha Island, Mono Lake Volcanic Field
Hot springs and their associated rising steam may be found in Hot Spring Cove on the southeastern point of Paoha Island in the Mono Lake Volcanic Field. USGS photo by Deborah Bergfeld.
Hot springs and their associated rising steam may be found in Hot Spring Cove on the southeastern point of Paoha Island in the Mono Lake Volcanic Field. USGS photo by Deborah Bergfeld.