Great Rift Valley Great Rift Valley The Great Rift Valley is a continuous geographic trench, approximately in length, that runs from Lebanon's Beqaa Valley in Asia to Mozambique in Southeastern Africa. The name continues in some usages, although it is today considered geologically imprecise as it combines features that are today regarded as separate, although related, rift and fault systems. Today, the term is most often used to refer to the valley of the East African Rift, the divergent plate boundary which extends from the Afar Triple Junction southward across eastern Africa, and is in the process of splitting the African Plate into
Volcanic history of the Northern Cordilleran Volcanic Province and inaccessible Coast Mountains south or southwest of Atlin Lake. On the south side of the Khutzeymateen Inlet north of Prince Rupert, thick basaltic Plinian eruption tephra deposits are recognized at Crow Lagoon. These volcanics originated from a volcanic vent that remains unidentified. However, existence of volcanic bombs at the Plinian tephra deposits indicates the volcanic vent of its origin is located nearby. The age of these volcanics is unknown but they were deposited throughout the Holocene epoch. In the Pleistocene Tuya Volcanic Field, small subaerial shield volcanoes and postglacial cinder cones and lava flows can be recognized. At least