Guichón Formation
Introduction The '''Guichón Formation''' is a Late Cretaceous geologic formation of the Paysandú Group in Uruguay. Dinosaur remains are among the fossils that have been recovered from the formation.
Description The Guichón Formation comprises mainly pink-greyish to reddish sandstones, which contain moderate to well-sorted, subrounded, fine to medium-sized grains in a pelitic matrix. These sandstones (which compositionally are feldspathic wackes) are either massive or may instead exhibit parallel lamination, cross-lamination and graded bedding. These lithologies were deposited in southwest-trending alluvial–fluvial systems comprising low-sinuosity channels traversing through sandy plains. Subordinate to the already mentioned sandstones are conglomeratic and pelitic lithologies, interpreted as channel-fill and overbank deposits, respectively. It is inferred that the Guichón Formation was deposited in warm, semi-arid climatic conditions. The formation has been correlated to the Puerto Yeruá Formation of northwestern Argentina.The formation reaches a thickness of more than  in wells perforating the formation. It is overlain by the Mercedes Formation and overlies the Arapey Formation.
Fossil content The following fossils have been reported from the formation:* ''Uruguaysuchus aznarezi''* Iguanodontia indet. * Saltasauridae indet. * Theropoda indet. ;Fossil eggs* ''Sphaerovum sp.''
See also * List of dinosaur-bearing rock formations** List of stratigraphic units with indeterminate dinosaur fossils* List of fossiliferous stratigraphic units in Uruguay
References === Bibliography ===* * * * *  * *