The formation comprises fine-grained sandstones and sandy limestones with stromatolites deposited in a shallow marine to lacustrine environment.

The formation has provided fossils of Dolichochampsa minima,[1] and ichnofossils of Ankylosauria indet., Ornithopoda indet., Theropoda indet.

[2][3][4] The tracksite of Cal Orcko is the best known example of the ichnofossil locations of the formation.

The ichnofossil of Ligabueichnum bolivianum may be attributed to an ankylosaur.

[5] The fossil fish species Dasyatis molinoensis is named after the formation.