Villeta Group

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Villeta Group
Stratigraphic range: Aptian-Coniacian
~125–87 Ma
Relieve Villetano.jpg
Villeta, type locality of the Villeta Group
TypeGeological group
Sub-unitsConejo Fm., La Frontera Fm., Simijaca Fm., Hiló Fm., Pacho Fm., , Capotes Fm., Socotá Fm., El Peñón Fm., Trincheras Fm.
UnderliesGuadalupe Group
OverliesLa Naveta Formation
Lithology
PrimarySandstone, shale, limestone
Location
Coordinates5°00′59″N 74°28′54″W / 5.01639°N 74.48167°W / 5.01639; -74.48167Coordinates: 5°00′59″N 74°28′54″W / 5.01639°N 74.48167°W / 5.01639; -74.48167
RegionAltiplano Cundiboyacense
Eastern Ranges, Andes
Country Colombia
Type section
Named forVilleta
Named byHumboldt
Year defined1810
Coordinates4°35′31″N 74°03′15″W / 4.59194°N 74.05417°W / 4.59194; -74.05417
RegionCundinamarca, Boyacá, Huila, Santander
Country Colombia
Blakey 105Ma - COL.jpg
Paleogeography of northern South America
105 Ma, by Ron Blakey

The Villeta Group (Spanish: Grupo Villeta) is a geological group of the Eastern Ranges of the Colombian Andes, to the west of the Altiplano Cundiboyacense. The group, a sequence of shales, limestones and sandstones, is subdivided into various formations; Conejo, La Frontera, Simijaca, Hiló, Pacho, , 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 of the Middle Magdalena Valley (VMM) and Sierra Nevada del Cocuy, the Oliní and of the Guaduas-Vélez synclinal and the Chipaque Formation of the Altiplano Cundiboyacense. The lower part has been correlated with the , and Paja Formations of the VMM, the upper , Une and Fómeque Formations of the Altiplano Cundiboyacense and the , , and upper of the Sierra Nevada del Cocuy.

Etymology[]

The group was first described by Alexander Von Humboldt around 1810 as the " Villeta Tonschiefer", german name for Villeta's clay slate.[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.[2]

Description[]

Lithologies[]

The sequence comprises an alternation of sandstones, shales and limestones and the lithologies and lateral facies variations are described in detail in the various formations comprising the group. Mineralizations of zinc, cadmium and molybdenum have been found in the Villeta Group.[3]

Stratigraphy and depositional environment[]

The Villeta Group overlies the La Naveta Formation and is overlain by the Guadalupe Group. The age has been estimated to be Aptian-Coniacian and the unit is subdivided into the Conejo, La Frontera, Simijaca, Hiló, Pacho Formations, the , and the Capotes, Socotá, El Peñón, and Trincheras Formations. 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.[2][4] The Villeta Group has been deposited in a marine environment and the organic rich shales and pelagic limestones and cherts of the Villeta Group and equivalent units comprise 60-70% of the Cretaceous record in the Eastern Ranges. They provide a good opportunity to study the interactions between tectonics eustatic sea level and sedimentation that regulate relative sea level in a basin.[5]

Outcrops[]

Villeta Group is located in the Bogotá savanna
Villeta Group
Type locality of the Villeta Group to the northwest of the Bogotá savanna

The formations of the Villeta Group are apart from its type locality near Villeta, found in other parts of the western flanks of the Eastern Ranges, stretching from Huila in the south to southern Santander in the north.[6][7][8][9][10][11][12][13][14][15][16]

Regional correlations[]

Cretaceous stratigraphy of the central Colombian Eastern Ranges
Age Paleomap VMM Guaduas-Vélez W Emerald Belt Villeta anticlinal Chiquinquirá-
Arcabuco		 Tunja-
Duitama		 Altiplano Cundiboyacense El Cocuy
Maastrichtian Blakey 065Ma - COL.jpg eroded Guaduas
Guadalupe
Campanian
Oliní
Santonian -
Coniacian Oliní Conejo Chipaque
Loma Gorda undefined La Frontera
Turonian Blakey 090Ma - COL.jpg Hondita La Frontera
Cenomanian hiatus Simijaca
Pacho Fm. Hiló - Pacho Une
Albian Blakey 105Ma - COL.jpg Hiló Une
Capotes - -
Aptian Capotes Socotá - El Peñón Paja Fómeque
Paja Paja El Peñón Trincheras
La Naveta
Barremian Blakey 120Ma - COL.jpg
Hauterivian
Las Juntas
Rosablanca Ritoque
Valanginian Ritoque - Murca Rosablanca hiatus Macanal
Rosablanca
Berriasian Blakey 150Ma - COL.jpg Guavio
Arcabuco
Sources


See also[]

Geology of the Eastern Hills
Geology of the Ocetá Páramo
Geology of the Altiplano Cundiboyacense

References[]

  1. ^ Humboldt, 1810, p. 11
  2. ^ a b Acosta & Ulloa, 2002, p.39
  3. ^ Acosta & Ulloa, 2001, p.14
  4. ^ Acosta & Ulloa, 2001, p.22
  5. ^ Villamil, 2012, p.161
  6. ^ Plancha 170, 2009
  7. ^ Plancha 171, 2009
  8. ^ Plancha 190, 2009
  9. ^ Plancha 191, 1998
  10. ^ Plancha 209, 2009
  11. ^ Plancha 210, 2010
  12. ^ Plancha 227, 1998
  13. ^ Plancha 245, 1999
  14. ^ Plancha 246, 1998
  15. ^ Plancha 264, 2000
  16. ^ Plancha 265, 1999

Bibliography[]

  • Humboldt, Alexander V.. 1810. Vues des Cordillères, et monumens des peuples indigenes de l'Amérique. . Accessed 2020-03-08.
  • Acosta, Jorge E., and Carlos E. Ulloa. 2002. Mapa geológico del Departamento de Cundinamarca 1:250,000 - Memoria Explicativa, 1-108. INGEOMINAS.
  • Acosta Garay, Jorge, and Carlos E. Ulloa Melo. 2001. Geología de la Plancha 208 Villeta - 1:100,000, 1-84. INGEOMINAS. Accessed 2018-05-12.
  • Villamil, Tomas. 2012. Chronology Relative Sea Level History and a New Sequence Stratigraphic Model for Basinal Cretaceous Facies of Colombia, 161–216. Society for Sedimentary Geology (SEPM).

Maps[]

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