Fish River Canyon

The Fish River Canyon, is located in the south of Namibia. It is the largest canyon in Africa, as well as the second most visited tourist attraction in Namibia. It features a gigantic ravine, in total about 100mi long, up to 27 km wide and in places almost 550 meters deep.The Fish River is the longest interior river in Namibia. It cuts deep into the plateau which is today dry, stony and sparsely covered with hardy drought-resistant plants. The river flows intermittently, usually flooding in late summer; the rest of the year it becomes a chain of long narrow pools. At the lower end of the Fish River Canyon, the hot springs resort of Ai-Ais is situated.Public view points are near Hobas, a camp site 70 km north of Ai-Ais. This part of the canyon is part of the Ai-Ais/Richtersveld Transfrontier Park. The other 90 km of this canyon are privately owned.GeologyThe Fish River canyon consists of an upper canyon, where river erosion was inhibited by hard gneiss bedrocks, and a lower canyon formed after erosion had finally worn through the gneisses.Upstream, the river runs through horizontal dolomite strata; these metamorphic rocks formed part of the canyon. About 650 million years ago (Mya), plate movement formed a north-south graben, or lowered area, along which the ancient Fish River could flow and eventually erode a flat plain, which is today's upper canyon. Glaciation at around 300 Mya, part of the Dyka glaciation during the Karoo Ice Age, further deepened the canyon. About 60 Mya, South America and Africa separated (due to continental drift) and Africa rose significantly; the consequentially increased gradient of the Fish River enabled it to erode the lower canyon into the hard gneisses, forming the current deeply twisting, meandering system of the lower canyon.