Great Dyke

Great Dyke, a linear geological formation extending about 520 km (about 320 mi) from northeast to southwest across central Zimbabwe. It was formed when molten rock forced its way into existing rock formations, which later eroded. The remaining intrusions consist of four long complexes of igneous rock, ranging from about 3 to 13 km (about 2 to 8 mi) wide, and varying in elevation from about 900 to 1,200 m (about 2,900 to 3,900 ft). The areas adjacent to the Great Dyke are densely populated and contain several of Zimbabwe’s larger urban centers, including Harare, Gweru, Kwekwe, Shurugwi, and Zvishavane.

Deposits of high-grade chromite ore found along the Great Dyke contribute significantly to Zimbabwe’s reserves of the mineral. The first chromite claims were staked during World War I (1914-1918), and large-scale mining began in the 1950s. Asbestos, copper, nickel, platinum, and gold are also extracted from the Great Dyke in significant quantities. While the surrounding regions contain excellent farmland, the dyke’s infertile and toxic soils, caused by the concentrated level of chromite, support little agriculture.