vredefort dome

Added in 2005, the Vredefort Dome is seventh on the list of South Africa's World Heritage Sites. Geologists are still arguing about the details, but all agree that it is the site of the largest and oldest recorded impact site in the world. Some say a meteorite hit the earth and vaporised after making a crater deep into the earth's crust, others suggest that it was a comet that collided and melted on impact. The area around Parys/Vredefort is only the eroded remains of the central cone of the crater that was uplifted 37km above the crater floor - the edges of the crater itself reached the Magaliesberg!

"Approximately 120 km south-west of Johannesburg, it is a representative part of a larger meteorite impact structure, or astrobleme. Dating back 2,023 million years, it is the oldest astrobleme yet found on Earth. With a radius of 190 km, it is also the largest and the most deeply eroded. Vredefort Dome bears witness to the world's greatest known single energy release event, which had devastating global effects including, according to some scientists, major evolutionary changes. It provides critical evidence of the Earth's geological history and is crucial to understanding of the evolution of the planet. Despite the importance of impact sites to the planet's history, geological activity on the Earth's surface has led to the disappearance of evidence from most of them, and Vredefort is the only example to provide a full geological profile of an astrobleme below the crater floor." (from whc.unesco.org/en/list/1162)


Facing west, all that remains of the central cone of the crater is an arc of hills north-west of the impact site.

Below is a satellite image that clearly shows the formation of the central cone - Potchefstoom is on the top centre-left, Parys just south of the hills, left of the u-bend in the Vaal River, and Vredefort is near the center of the cone. www.hartrao.ac.za/other/vredefort/vredefort.html has some info about the impact and geology, while www-za.tvdc.co.za has info about the conservancy area.