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.
Medicine Lake
Medicine Lake Volcano is a large shield volcano in northeastern California about 50 kilometers (30 mi) northeast of Mount Shasta. The volcano is located in a zone of east-west crustal extension east of the main axis of the Cascade Volcanic Arc and the Cascade Range. The 1-kilometer (0.6 mi) thick shield is 35 km (22 mi) from east to west and 45 to 50 km (28 to 31 mi) from north to south, and covers more than 2,000 km (770 sq mi). The underlying rock has downwarped by 0.5 km (0.3 mi) under the center of the volcano. The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a 7 by 12 km (4.3 by 7.5 mi) caldera at the center.
Medicine Lake
The Medicine Lake shield rises about 1,200 meters (3,900 ft) above the Modoc Plateau to an elevation of 2,376 meters (7,795 ft). Lavas from Medicine Lake Volcano are estimated to be at least 600 km (140 cu mi) in volume, making Medicine Lake the largest volcano by volume in the Cascade Range (Newberry Volcano in Oregon has the second largest volume). Lava Beds National Monument lies on the northeast flank of the volcano.
Originally posted 2010-08-27 03:17:06.
