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El Peñón Formation
El Peñón Formation
Stratigraphic range: Late Aptian; ~115–112 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
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 / 5.25361°N 74.34111°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 / 5.25361°N 74.34111°W
Region	Cundinamarca
Country	Colombia
Thickness at type section	381 m (1,250 ft)
	; Paleogeography of Northern South America; 120 Ma, by Ron Blakey

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.

Etymology

The formation was defined and named in 1982 by Ulloa after El Peñón, Cundinamarca.^[1]

Description

Lithologies

The El Peñón Formation has at is type section a thickness of 381 metres (1,250 ft),^[2] and is characterised by a sequence of calcareous shales and siltstones. The middle part of the sequence contains gypsum.^[3] Fossils of the ammonites Cheloniceras sp. and Epicheloniceras sp. aff. carlosacostai have been found in the El Peñón Formation.^[1]

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.^[4] The age has been estimated to be Late Aptian.^[1] Stratigraphically, the formation is time equivalent with the Tablazo Formation and a lateral facies equivalent of the Socotá Formation.^[5] The formation has been deposited in a shallow marine platform environment.^[1] In the Late Aptian, central Colombia was dominated by shallow marine carbonate platform environments.^[6]

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,^[1] between Bituima and Guayabal de Síquima,^[7] and along the road from Villeta to Sasaima.^[2]

Regional correlations

Cretaceous stratigraphy of the central Colombian Eastern Ranges
Age	VMM	Guaduas-Vélez		W Emerald Belt		Villeta anticlinal		Chiquinquirá- Arcabuco	Tunja- Duitama	Altiplano Cundiboyacense		El Cocuy
Maastrichtian	Umir	Córdoba		Seca		eroded		Guaduas				Colón-Mito Juan
Maastrichtian				Umir				Guadalupe
Campanian				Córdoba
Campanian				Oliní
Santonian	La Luna	Cimarrona - La Tabla										La Luna
Coniacian		Oliní				Villeta	Conejo		Chipaque
Coniacian		Güagüaquí	Loma Gorda	undefined			La Frontera
Turonian		Güagüaquí	Hondita	La Frontera	Otanche		La Frontera
Cenomanian	Simití	hiatus		La Corona			Simijaca					Capacho
Cenomanian				Pacho Fm.			Hiló - Pacho	Churuvita	Une			Aguardiente
Albian				Hiló			Hiló - Pacho	Chiquinquirá	Tibasosa	Une		Aguardiente
Albian	Tablazo			Tablazo			Capotes - La Palma - Simití	Simití		Une		Tibú-Mercedes
Aptian	Tablazo			Capotes			Socotá - El Peñón	Paja		Fómeque		Tibú-Mercedes
	Paja			Paja	El Peñón		Trincheras					Río Negro
						La Naveta
Barremian
Hauterivian					Muzo					Cáqueza	Las Juntas
Hauterivian	Rosablanca				Muzo			Ritoque			Las Juntas
Valanginian				Ritoque	Furatena	Útica - Murca		Rosablanca	hiatus		Macanal
Valanginian				Rosablanca	Furatena			Rosablanca			Macanal
Berriasian	Cumbre			Cumbre				Los Medios			Guavio
Berriasian	Tambor			Arcabuco				Cumbre			Guavio
Sources

References

^ ^a ^b ^c ^d ^e Acosta & Ulloa, 2002, p.42
^ ^a ^b Acosta & Ulloa, 2001, p.27
^ Acosta & Ulloa, 2001, p.29
^ Acosta & Ulloa, 2001, p.30
^ Acosta & Ulloa, 2001, p.16
^ Villamil, 2012, p.164
^ Plancha 227, 1998

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