Pacho Formation

The Pacho Formation (, Kslp) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consisting of alternating siltstones and shales with siderite concretions dates to the Middle Cretaceous period; Late Albian to Cenomanian epochs and has an approximate thickness of .
Etymology.
The formation was defined and named in 1982 by Ulloa after Pacho, Cundinamarca.
Description.
Lithologies.
The Pacho Formation has an approximate thickness of , and is characterised by a sequence of alternating siltstones and shales with siderite concretions.
Stratigraphy and depositional environment.
The Pacho Formation, pertaining to the Villeta Group, partly overlies and is partly lateral equivalent with the Hiló Formation and is partly overlain by and partly time equivalent with the Simijaca Formation. The age has been estimated to be Late Albian to Cenomanian. Stratigraphically, the formation is time equivalent with the Une Formation. The formation has been deposited in an outer marine platform environment.
Outcrops.
The Pacho Formation is found around its type locality near Pacho.