 Ultrapotassic lamprophyre dikes can also be found along the basin flanks, which are highly unusual in the Rocky Mountain region.The site of the Raton Basin was a coastal plain at the end of Cretaceous and beginning of Paleogene time, and has a well-preserved sequence of rocks spanning the Cretaceous–Paleogene boundary.For this reason, the Raton Basin has been studied for evidence of the iridium anomaly thought to be evidence for a large meteor impact at the end of the Cretaceous that is in turn thought to have caused the Cretaceous–Paleogene extinction event.