Great Rift Valley support its current biological variety. The southern section of the Rift Valley includes Lake Malawi, the third-deepest freshwater body in the world, reaching in depth and separating the Nyassa plateau of Northern Mozambique from Malawi; it ends in the Zambezi 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
Geology of the Lassen volcanic area south and east, reaching the head of Warner Valley. By this time, the park's eastern portion had been transformed into a relatively flat plain. The activity was followed by an eruption of the Eastern basalts from volcanoes east of the park. These thick flows have subsequently eroded to produce rugged hills that limit the park on the east. Taken together, these various flows built the lava plateau that the Lassen volcanic area is located on. From 600,000 to 400,000 years ago, eruptions built a large conical stratovolcano called Mount Tehama (also called Brokeoff Volcano) in what is now the southwest