The predominantly organic shale formation dates to the Early Cretaceous period; Barremian to Late Aptian epochs and has a maximum thickness of 1,200 metres (3,900 ft).

The formation was defined and named in 1957 by Hubach after Fómeque, Cundinamarca.

[1] The Fómeque Formation has a maximum thickness of 1,200 metres (3,900 ft), and is characterised by a sequence of pyritic organic shales, with limestones and sandstone banks intercalated in the formation.

[2] Fossils of Acarthohoplites sp., Melchionites sp., Nicklesia sp., Olcostephanus sp., Pulchellia sp.

[2] The Fómeque Formation is apart from its type locality, found in other parts of the Eastern Ranges.