major division of late Precambrian rocks (the Precambrian era began about 3.8 billion years ago and ended 540 million years ago) in central Africa, especially in Katanga province, Congo (Kinshasa). The Katangan Complex is a complicated array of diverse sedimentary and metamorphic rocks; Katangan rocks consist of shales, quartzites, limestones, sandstones, dolomites, and slates more than 7,000 m (23,000 feet) thick. The Katangan has been radiometrically dated at more than 620 million years in age. Katangan rocks are of tremendous economic importance; copper, cobalt, uranium, zinc, and other valuable minerals are abundant.