Fish River Canyon

Fish River Canyon, in southern Namibia, is one of the largest canyons in Africa, extending some 160 kilometers in length and reaching depths of up to 550 meters, cut into an ancient basement of quartzite, gneiss, dolerite and lava roughly 1,000 to 2,600 million years old. Its formation began with a broad, shallow valley that developed along a zone of crustal weakness associated with regional rifting and faulting some 500 million years ago; renewed tectonic uplift much later steepened the terrain, and the Fish River, exploiting the pre-existing fault-weakened rock, incised a deep, steep-walled gorge whose winding course still reflects the underlying structural control of ancient faults and joints rather than a purely erosional meander. Along with the Grand Canyon in the United States, it is frequently cited among the largest canyons on Earth by combined length, depth and width.