Toqui Formation

The Toqui Formation is a geological formation in the Aysén Region of southern Chile. It has been dated to the Tithonian stage of the Late Jurassic by uranium–lead dating of zircons, providing an age of 147 ± 0.1 Ma. It consists of an sequence of clastic sedimentary sandstones and conglomerates, interbedded with volcanic tuffs and ignimbrite. The dinosaurs "Chilesaurus" and indeterminate diplodocids are known from the formation. The formation was deposited in a fluvio-deltaic environment.