Cerro Carnerero Formation

The Cerro Carnerero Formation is a geological formation of the Golfo San Jorge Basin in Chubut Province, Patagonia, Argentina.
Description.
The claystones and tuffs of the approximately thick formation, belonging to the Lonco Trapial Group, were deposited in a fluvial environment.
The formation dates back to the Middle Jurassic (Toarcian stage) and has preserved fossils of "Cladophlebis oblonga", and "Amygdalodon patagonicus".
The fossiliferous beds rest on Liassic beds with "Harpoceras subplanatum", and below the Middle to Upper Jurassic Porphyritic Series. Called the "Cerro Carnerero" beds, Rauhut, 2008, assigned the Cerro Carnerero to the Toarcian to Bajocian.
Lithology.
The formation comprises sandy tuffs and bluish gray claystones, which form part of a continental sedimentary series mixed with porphyritic conglomerates with partly encrusted round pebbles, and bluish gray clays with sandy intercalations and clays in lesser amounts.