El Peñón Formation

The El Peñón Formation (Spanish: Formación El Peñón, Kipe) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of calcareous shales and siltstones and dates to the Early Cretaceous period; Late Aptian epoch and has a measured thickness at its type section of 381 metres (1,250 ft). Ammonite fossils have been found in the formation, deposited in a shallow marine platform environment.

El Peñón Formation
Stratigraphic range: Late Aptian ~
Type	Geological formation
Unit of	Villeta Group
Underlies	Capotes Formation
Overlies	Trincheras Formation
Thickness	more than 381 m (1,250 ft)
Lithology
Primary	Calcareous shale
Other	Siltstone, gypsum
Location
Coordinates	5°15′13″N 74°20′28″W
Region	Altiplano Cundiboyacense Eastern Ranges, Andes
Country	Colombia
Type section
Named for	El Peñón
Named by	Ulloa
Location	El Peñón
Year defined	1982
Coordinates	5°15′13″N 74°20′28″W
Region	Cundinamarca
Country	Colombia
Thickness at type section	381 m (1,250 ft)
Paleogeography of Northern South America 120 Ma, by Ron Blakey

Etymology

The formation was defined and named in 1982 by Ulloa after El Peñón, Cundinamarca.

Description

Lithologies

The El Peñón Formation has at is type section a thickness of 381 metres (1,250 ft), and is characterised by a sequence of calcareous shales and siltstones. The middle part of the sequence contains gypsum. Fossils of the ammonites Cheloniceras sp. and Epicheloniceras sp. aff. carlosacostai have been found in the El Peñón Formation.

Stratigraphy and depositional environment

The El Peñón Formation, part of the Villeta Group, conformably overlies the Trincheras Formation and is conformably overlain by the Capotes Formation. The age has been estimated to be Late Aptian. Stratigraphically, the formation is time equivalent with the Tablazo Formation and a lateral facies equivalent of the Socotá Formation. The formation has been deposited in a shallow marine platform environment. In the Late Aptian, central Colombia was dominated by shallow marine carbonate platform environments.

Outcrops

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Type locality of the El Peñón Formation to the west of the Altiplano Cundiboyacense

The El Peñón Formation, restricted to Cundinamarca, is locally found around its type locality, between Bituima and Guayabal de Síquima, and along the road from Villeta to Sasaima.

See also

Geology of the Eastern Hills

Geology of the Ocetá Páramo

Geology of the Altiplano Cundiboyacense

References

Bibliography

• Acosta Garay, Jorge E.; Ulloa Melo, Carlos E. (2002), Mapa Geológico del Departamento de Cundinamarca - 1:250,000 - Memoria explicativa, INGEOMINAS, pp. 1–108, retrieved 2017-04-26
• Acosta Garay, Jorge; Ulloa Melo, Carlos E. (2001), Geología de la Plancha 208 Villeta - 1:100,000 (PDF), INGEOMINAS, pp. 1–84, retrieved 2017-06-05 Archived 2017-03-24 at the Wayback Machine
• Villamil, Tomas (2012), Chronology Relative Sea Level History and a New Sequence Stratigraphic Model for Basinal Cretaceous Facies of Colombia, Society for Sedimentary Geology (SEPM), pp. 161–216

Maps

• Ulloa, Carlos; Acosta, Jorge (1998), Plancha 208 - Villeta - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
• Ulloa, Carlos E; Rodríguez, Erasmo; Acosta, Jorge E. (1998), Plancha 227 - La Mesa - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06

External links

• Gómez, J.; Montes, N.E.; Nivia, Á.; Diederix, H. (2015), Plancha 5-09 del Atlas Geológico de Colombia 2015 – escala 1:500,000, Servicio Geológico Colombiano, p. 1, retrieved 2017-03-16