Английская Википедия:El Peñón Formation

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Шаблон:Infobox rockunit The El Peñón Formation (Шаблон:Lang-es, 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 Шаблон:Convert. 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 Шаблон:Convert,[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

Шаблон:Location map 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]

Шаблон:Clearleft

Regional correlations

Шаблон:Cretaceous stratigraphy of the central Colombian Eastern Ranges

See also

Шаблон:Portal

Шаблон:Icon Geology of the Eastern Hills
Шаблон:Icon Geology of the Ocetá Páramo
Шаблон:Icon Geology of the Altiplano Cundiboyacense

Шаблон:Clearboth

References

Шаблон:Reflist

Bibliography

Maps

External links

  1. 1,0 1,1 1,2 1,3 1,4 Acosta & Ulloa, 2002, p.42
  2. 2,0 2,1 Acosta & Ulloa, 2001, p.27
  3. Acosta & Ulloa, 2001, p.29
  4. Acosta & Ulloa, 2001, p.30
  5. Acosta & Ulloa, 2001, p.16
  6. Villamil, 2012, p.164
  7. Plancha 227, 1998