A Revision of the Formation Conditions of the Vredefort Crater

A revised model of the Vredefort Crater, Earth's largest confirmed remnant impact structure, challenges long-standing estimates of its formation. Using advanced shock physics simulations (iSALE), researchers determined that an impactor diameter of 20–25 km and velocity of 15–25 km/s could recreate the observed crater size (~250 km) and geological features, including breccia, shatter cones, and melt distributions. This contradicts prior estimates (15 km diameter, 15 km/s), which failed to align with recent geological constraints. The model also predicts that Vredefort and Karelia, Russia—where ejecta from the impact was found—were 2,000–2,500 km apart at the time. Additionally, it estimates atmospheric gas release during such a massive impact, underscoring the need to re-evaluate parameters for large terrestrial craters.

Allen, N. H., Nakajima, M., Wünnemann, K., Helhoski, S., & Trail, D. (2022). A Revision of the Formation Conditions of the Vredefort Crater. Journal of Geophysical Research: Planets, 127(8). Portico. https://doi.org/10.1029/2022je007186