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Country: | United States | |
| Subregion Name: | California (USA) | ||
| Volcano Number: | 1203-02- | ||
| Volcano Type: | Shield volcano | ||
| Volcano Status: | Radiocarbon | ||
| Last Known Eruption: | 1080 ± 25 years | ||
| Summit Elevation: | 2412 m | 7,913 feet | |
| Latitude: | 41.611°N | 41°36'40"N | |
| Longitude: | 121.554°W | 121°33'13"W | |
| Medicine Lake is a large Pleistocene-to-Holocene, basaltic-to-rhyolitic shield volcano east of the main axis of the Cascade Range. Medicine Lake volcanism, similar in style to that of Newberry volcano in Oregon, began less than one million years ago. A roughly 7 x 12 km caldera truncating the summit contains a lake that gives the volcano its name. A series of young eruptions lasting a few hundred years began about 10,500 years before present (BP) and produced 5 cu km of basaltic lava. Eruptive activity resumed 6000 years later, producing a chemically varied group of basaltic lava flows from flank vents and silicic obsidian flows from vents within the caldera and on the upper flanks. The last eruption produced the massive Glass Mountain obsidian flow on the east flank about 900 years BP. Lava Beds National Monument on the northern flank of Medicine Lake shield volcano contains hundreds of lava-tube caves displaying a variety of spectacular lava-flow features, most of which are found in the voluminous Mammoth Crater lava flow, which extends in several lobes up to 24 km from the vent. | |||
