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 caldera 900,000 years ago. As well, subglacial eruptions around the flanks of Mount Edziza and Ice Peak constructed piles of pillow lava and hyaloclastite. Prindle Volcano, the northernmost volcano of the Northern Cordilleran Volcanic Province and one of the most isolated volcanoes in Alaska, was formed on the Yukon-Tanana upland during the Pleistocene epoch. It is a small cinder cone made of basanite with a deep breached volcanic crater at its summit. Extending from Prindle's breached volcanic crater is a long basanite lava flow that flowed southeast of the cone then flowed southwest into a river valley. The Cassiar Mountains