Vredefort crater

The Vredefort crater is the largest verified impact crater on Earth, more than 300 km (186 mi) across when it was formed. What remains of it is located in the present-day Free State Province of South Africa and named after the town of Vredefort, which is situated near its center. Although the crater itself has long since eroded away, the remaining geological structures at its center are known as the Vredefort Dome or Vredefort impact structure. The crater is estimated to be 2.023 billion years old (± 4 million years), with impact being in the Paleoproterozoic Era. It is the second-oldest known crater on Earth.In 2005, the Vredefort Dome was added to the list of UNESCO World Heritage Sites for its geologic interest.Formation and structureThe asteroid that hit Vredefort is estimated to have been one of the largest ever to strike Earth (at least since the Hadean Eon some four billion years ago), thought to have been approximately 10– in diameter. The bolide that created the Sudbury Basin could have been even larger.The original crater was estimated to have a diameter of roughly 300km, although this has been eroded away. It would have been larger than the 250km Sudbury Basin and the 180km Chicxulub Crater. The remaining structure, the "Vredefort Dome", consists of a partial ring of hills 70 km in diameter, and are the remains of a dome created by the rebound of rock below the impact site after the collision.