Cima Dome & Volcanic Field National Natural Landmark

關於

Cima volcanic field is a volcanic field in San Bernardino County, California, close to the border with Nevada. The volcanic field covers a surface area of 600 km2 (230 mi2) within the Mojave National Preserve west of the Cima Dome and consists of about 40 volcanic cones with about 60 lava flows. The volcanic cones range from simple cones over multi-cratered mountains to eroded hills, and lava flows are up to 9.1 km (5.7 mi) long. At least one lava tube exists in the field and can be visited.

Volcanic activity in the field commenced in the Late Miocene and after a pause between 3 and 1 million years ago continued into the latest Pleistocene. The youngest cone is known as the Black Tank cone and formed about 15,000 years before present, although it is possible that it was formed through two separate eruption events; formerly it was considered to be of historical age.

內容改寫自 Wikipedia (CC BY-SA)。照片來自 Wikimedia Commons.