Bushveld Igneous Complex

The Bushveld Igneous Complex (BIC) is a large layered igneous intrusion within the Earth's crust which has been tilted and eroded and now outcrops around what appears to be the edge of a great geological basin, the Transvaal Basin. Located in South Africa, the BIC contains some of the richest ore deposits on Earth.

The complex contains the world's largest reserves of platinum-group metals (PGMs)—platinum, palladium, osmium, iridium, rhodium, and ruthenium—along with vast quantities of iron, tin, chromium, titanium and vanadium.

Gabbro or norite is also quarried from parts of the Complex and rendered into dimension stone. The site was discovered around 1897 by Gustaaf Molengraaff.

The Bushveld Igneous Complex covers a pear-shaped area in the central Transvaal. It is divided into an eastern and western lobe, with a further northern extension.

All three sections of the system were formed around the same time—about 2 billion years ago—and are remarkably similar. Vast quantities of molten rock from Earth's mantle were brought to the surface through long vertical cracks in Earth's crust—huge arcuate differentiated lopolithic intrusions—creating the geological intrusion known as the Bushveld Igneous Complex.

...
Wikipedia