The formation consists of grey claystones intercalated by orange quartz siltstones and sandstones of small to conglomeratic grain size.

In the formation, dated on the basis of its fossil content to the Late Oligocene, many leaf imprints and mollusks were found, suggesting a lacustrine to deltaic depositional environment with periodical marine incursions.

The formation comprises grey claystones intercalated by orange quartz siltstones and sandstones of small to conglomeratic grain size.

[1] In these thick packages of claystones, the formation has provided fossil leaves in various forms and sizes, and to a lesser extent the remains of mollusks; gastropods and bivalves.

[1] The grain composition of the lithic fraction comprises zircon,[3] epidote, zoisite, clinozoisite and pyroxenes, which at the top of the formation amounts to 86 percent.

[1] The abundance of lithic clasts near the top of the formation supports a renewed provenance area to the east; the uplift of the Eastern Ranges of the Colombian Andes,[6] due to activity of the La Salina Fault.