Topic summary
Los Colorados Formation
The Los Colorados Formation is a sedimentaryrock formation of the Ischigualasto-Villa Unión Basin, found in the provinces of San Juan and La Rioja in Argentina. The formation dates back to the Norian age of the Late Triassic.
The up to 600 metres (2,000 ft) thick formation comprises sandstones, siltstones, mudstones and conglomerates with gypsum layers deposited in a fluvial to lacustrineenvironment. The formation is the uppermost stratigraphic unit of the , overlying the Lagerstätte of the Ischigualasto Formation. Los Colorados Formation is partly covered by the Cretaceous , separated by an unconformity.
The formation is known for its fossils of early dinosaurs, including the coelophysoidZupaysaurus and the "prosauropods" Coloradisaurus, Lessemsaurus, and Riojasaurus. Magnetostratigraphic analysis suggests that the Los Colorados Formation was deposited between 227 and 213 million years ago.