Medicine Lake Volcano Medicine Lake Volcano Medicine Lake Volcano is a large shield volcano in northeastern California about 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 thick shield is from east to west and from north to south, and covers more than . The underlying rock has downwarped by under the center of the volcano. The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a caldera at the center. The Medicine Lake shield rises about above
The Volcano (British Columbia) of the much larger Northern Cordilleran Volcanic Province, which extends from the Alaska–Yukon border to near the port city of Prince Rupert, British Columbia. Eruptive activity at The Volcano is relatively young compared to most other volcanoes in the Northern Cordilleran Volcanic Province. Geologic studies have shown that The Volcano and its eruptive products were emplaced in the past 400 years; this is well after the last glacial period, which ended about 10,000 years ago. The Volcano is the southernmost of 10 volcanoes comprising the Iskut-Unuk River Cones volcanic field, as well as the most recent to erupt. Its structure