The bolide which formed the crater was at least 10 km (6 mi) in diameter. Evidence for the impact origin of the crater includes shocked quartz, a gravity anomaly, and tektites in surrounding areas. The age of the rocks and isotope analysis show that this impact structure dates from the end of the Cretaceous period, roughly 66 million years ago. The impact associated with the crater is implicated in causing the extinction of the dinosaurs.