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Mono Lake Volcanic Field

The Mono Lake volcanic field, east of Yosemite National Park and north of the Mono Craters, consists of vents within Mono Lake and on its north shore. The most topographically prominent feature, Black Point, is an initially sublacustral (below lake level) basaltic cone that rises above the northwest shore and was formed about 13,300 years ago when Mono Lake was higher. Holocene rhyodacitic lava domes and flows form Negit and parts of Paoha islands off the northern shore and center of the lake, respectively. The most recent eruptive activity in the Long Valley to Mono Lake region took place 100-230 years ago, when lake-bottom sediments forming much of Paoha Island were uplifted by intrusion of a rhyolitic dome that never reached the surface. This type of dome is called a cryptodome. Spectacular tufa towers line the shores of Mono Lake.