It was formed by the impact of an asteroid or comet approximately 142.5 ± 0.8 million years ago, in the earliest Cretaceous Period, very close to the Jurassic – Cretaceous boundary. The original crater rim has been estimated at about 22 km (13.7 Mi) in diameter, but this has been eroded away. The 5 km (3 mi) diameter, 150 m (500 ft) high crater-like feature, now exposed, is interpreded as the eroded relic of the crater’s central uplift. The impact origin of this topographic feature was first proposed in the 1960s, the strongest evidence coming from the abundance of shatter cones.
The site is known as Tnorala to the Western Arrernte Aboriginal people, and is a sacred place. It is now located in the Tnorala Conservation Reserve.
In the past the crater has been the target of petroleum exploration, and two abandoned exploration wells lies near its centre.