The predominantly sandstone formation dates to the Early Cretaceous period; Hauterivian epoch, and has a maximum thickness of 910 metres (2,990 ft).

The formation was defined and named in 1979 by Rodríguez and Ulloa after Cerro Las Juntas, Guateque, Tenza Valley, Boyacá.

[1][2] The Las Juntas Formation has a maximum thickness of 910 metres (2,990 ft) and is characterised by a sequence of sandstones with interbedded shales.

The formation has been deposited in a near shore deltaic environment,[1][2] with as provenance areas the Santander High and the Guiana Shield.

[5] The Las Juntas Formation is apart from its type locality east of Guateque, found in Chingaza National Park,[1] in the El Cochal Synclinal east of the Ocetá Páramo,[6] between Lake Tota and Labranzagrande,[7] other parts of the Tenza Valley such as close to Macanal and Almeida.