The formation consisting of a lower unit of calcareous shales and an upper sequence of shales dates to the Early Cretaceous period; Early Aptian epoch and has a maximum thickness of 1,260 metres (4,130 ft).

The formation, deposited in a marine platform environment, part of a transgressive cycle, hosts ammonite, bryozoan, mollusc and echinoid fossils.

The formation was defined and named in 1969 by Cáceres and Etayo after Quebrada Trincheras, Apulo, Cundinamarca.

[1] The Trincheras Formation has a maximum thickness of 1,260 metres (4,130 ft),[2] and is characterised by a sequence of claystones with intercalated limestones and sandstones.

[2] The formation also crops out around San Joaquín east of La Mesa,[6] and on the right bank of the Bogotá River near Apulo.