Diamond Craters

Diamond Craters is a volcanic field^[2] or small shield volcano^[3] in southeastern Oregon, about 40 miles (64 km) southeast of the town of Burns. It consists of a 23 sq mi (60 km²) area of basaltic lava flows, cinder cones, and maars.^[2] The volcanoes are less than 60,000 years old, and some craters may be as recent as 6,000 years based on the sedimentation history in the lake-filled Malheur Maar.^[1]

• http://en.wikipedia.org/wiki/Diamond Craters