Corossol crater

The Corossol structure is a circular, bedrock feature that is argued to be a deeply eroded impact structure located in the Gulf of Saint Lawrence near Sept-Îles, Quebec (Canada). It lies underwater at a depth of 40–208 meters (131–682 ft), it was created as a result of the impact of a meteorite of about 300 meters (980 ft) in diameter. Detailed analysis of high-resolution Multibeam echosounder and seismic reflection data indicates that rivers deeply eroded the Corossol structure and Paleozoic sedimentary rocks comprising the surrounding sea bottom during periods of pre-Quaternary sea-level low stands and continental ice sheets further eroded it during the Quaternary. Stratigraphic and geomorphic relationships indicate that this impact structure formed sometime after Middle Ordovician, about 470 million years ago, and before the first continental glaciations of North America at the beginning of the Quaternary, about 2.6 million years ago.