The Vredefort dome, the central part of the Vredefort impact structure, is a prominent 80 km wide feature of the Kaapvaal craton. Its location at the centre of the Witwatersrand basin, from which almost half of the world’s total gold production has been extracted, has made it a focus of geological study for more than a century.

The origin of the +/- 80 km-wide Vredefort dome, located south west of Johannesburg, has been debated for the best part of the last century. It is now, however, universally accepted that the Vredefort dome represents the central position of a deeply eroded, complex impact structure the Vredefort impact structure that formed 2 023 +/- 4 Ma ago in Archaen and Palaeoproterozoic rocks of the Kaapvaal craton. This structure is the oldest and, with an estimated original diameter of 250 300 km, the largest impact feature identified thus far on Earth. At this size, it encompasses the entire extent of the economically important Witwatersrand basin. The Witwatersrand part of this basin was largely preserved due to downwarping / inward-directed megablock slumping of Witwatersrand rocks and their associated gold and uranium resources as a result of the Vredefort impact event. Recent results have shown that the Vredefort impact structure is also one of the most deeply eroded impact structures known, with current levels of exhumation estimated to represent post-impact depths of between 8 and 11 km. Besides providing a unique window into the deep levels of a very large, complex structure, the Vredefort structure also permits detailed studies of more than 3 billion years of geological evolution of the crust of the Kaapvaal craton.

By reservation only, trips to the highest point of the Vredefort Dome are being offered and can be combined with a meal and explanation of the impact site