The group, a sequence of shales, limestones and sandstones, is subdivided into various formations; Conejo, La Frontera, Simijaca, Hiló, Pacho, Chiquinquirá, Capotes, Socotá, El Peñón, and Trincheras, and dates to the Cretaceous period; Aptian-Coniacian epochs.

The group stretches out across four departments, from Huila in the south, through Cundinamarca and Boyacá to southern Santander in the north.

The upper part of the Villeta Group is time-equivalent with the La Luna Formation of the Middle Magdalena Valley (VMM) and Sierra Nevada del Cocuy, the Oliní and Güagüaquí Groups of the Guaduas-Vélez synclinal and the Chipaque Formation of the Altiplano Cundiboyacense.

[1] The group was subsequently published in 1892 by Hettner in his book Die Kordilleren von Bogotá and named after its type locality Villeta on the western flanks of the Eastern Ranges of the Colombian Andes.

The core extent of the group has been defined by Cáceres and Etayo in 1969, running from Apulo in the south to Muzo in the north.