Siljan Ring Siljan Ring The Siljan Ring () is a prehistoric impact crater in Dalarna, central Sweden. It is one of the 15 largest known impact craters on Earth and the largest in Europe, with a diameter of about . The impact that created the Siljan Ring occurred when a meteorite collided with the Earth's surface during the Devonian period, about 376.8 ± 1.7 Ma. This coincides around the first Devonian extinction, the Kellwasser Event or Late Frasnian extinction at 376.1 Ma ± 1.6 Ma. The effects of the impact can clearly be seen in the bedrock in the area. The Cambrian,
Mora County, New Mexico 1970s; the 2016 estimate was 4,500. Prior to Spanish conquest, the Mora area was Native American country. Although not an area of heavy settlement by stationary tribes such as the Puebloans, the Mora Valley was often used by nomadic nations, including the Ute, Navajo, and Apache. Hispano settlers had occupied lands within the Mora Valley without legal title ever since Governor Juan Bautista de Anza of Nuevo México (then under the authority of the Spanish Empire) made peace with the Comanches in the late 18th century, opening up the east side of the Sangre de Cristo Mountains for settlement. The