[2][3][4] At the type section, the Onate Formation consists of about 85–95 feet (26–29 m) of orange yellow-weathering dolomitic siltstone with shales and sandstone.

[3] The formation is interpreted as having been deposited on a shallow shelf environment deepening to a euxenic basin to the south.

Conodonts are rare but a few tabulate corals, ichnofossils, and the receptaculid Sphaerospongia is present.

The receptaculids provided a solid substrate for colonization by the rugose coral Tabulophyllum traversensis.

Stevenson questioned the correlation, and designated a new Onate Formation including the beds in 1945.