Villeta Group

Villeta Group
Stratigraphic range: Aptian-Coniacian
~125–87 Ma
Villeta, type locality of the Villeta Group
Type Geological group
Sub-units Conejo Fm., La Frontera Fm., Simijaca Fm., Hiló Fm., Pacho Fm., Chiquinquirá Sst., Capotes Fm., Socotá Fm., El Peñón Fm., Trincheras Fm.
Underlies Guadalupe Group
Overlies La Naveta Formation
Lithology
Primary Sandstone, shale, limestone
Location
Coordinates 5°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
Region Altiplano Cundiboyacense
Eastern Ranges, Andes
Country  Colombia
Type section
Named for Villeta
Named by Hettner
Year defined 1892
Coordinates 4°35′31″N 74°03′15″W / 4.59194°N 74.05417°W / 4.59194; -74.05417
Region Cundinamarca, Boyacá, Huila, Santander
Country  Colombia

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, Chiquinquirá, 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 La Luna Formation of the Middle Magdalena Valley (VMM) and Sierra Nevada del Cocuy, the Oliní and Güagüaquí Groups of the Guaduas-Vélez synclinal and the Chipaque Formation of the Altiplano Cundiboyacense. The lower part has been correlated with the Simití, Tablazo and Paja Formations of the VMM, the upper Tibasosa, Une and Fómeque Formations of the Altiplano Cundiboyacense and the Capacho, Aguardiente, Tibú-Mercedes and upper Río Negro Formations of the Sierra Nevada del Cocuy.

Etymology

The group was published in 1892 by Hettner and named after its type locality Villeta on the western flanks of the Eastern Ranges of the Colombian Andes.[1]

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.[2]

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 Chiquinquirá Sandstone, 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.[1][3] 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.[4]

Outcrops

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.[5][6][7][8][9][10][11][12][13][14][15]

Regional correlations

Cretaceous stratigraphy of the central Colombian Eastern Ranges
AgePaleomapVMMGuaduas-VélezW Emerald BeltVilleta anticlinalChiquinquirá-
Arcabuco		Tunja-
Duitama		Altiplano CundiboyacenseEl Cocuy
MaastrichtianUmir Fm.Córdoba Fm.Seca Fm.erodedGuadalupe Gp.Colón-Mito Juan Fm.
Umir Fm.
CampanianCórdoba Fm.
Oliní Gp.
SantonianLa Luna Fm.Cimarrona Fm. - La Tabla Fm.La Luna Fm.
ConiacianOliní Gp.Conejo Fm.Chipaque Fm.
Güagüaquí Gp
Loma Gorda Fm.undefinedLa Frontera Fm.
TuronianHondita Fm.La Frontera Fm.Otanche Fm.
CenomanianSimití Fm.hiatusLa Corona Gb.Simijaca Fm.Capacho Fm.
Pacho Fm.Hiló Fm. - Pacho Fm.Churuvita Fm.Une Fm.Aguardiente Fm.
AlbianHiló Fm.Chiquinquirá Sst.Tibasosa Fm.Une Fm.
Tablazo Fm.Tablazo Fm.Capotes Fm. - La Palma Fm. - Simití Fm.Simití Fm.Tibú-Mercedes Fm.
AptianCapotes Fm.Socotá Fm. - El Peñón Fm.Paja Fm.Fómeque Fm.
Paja Fm.Paja Fm.El Peñón Fm.Trincheras Fm.Río Negro Fm.
La Naveta Fm.
Barremian
HauterivianMuzo Fm.
Cáqueza Gp
Las Juntas Fm.
Rosablanca Fm.Ritoque Fm.
ValanginianRitoque Fm.Furatena Fm.Útica Fm. - Murca Fm.Rosablanca Fm.Girón Fm.Macanal Fm.
Rosablanca Fm.
BerriasianCumbre Fm.Cumbre Fm.Los Medios Fm.Guavio Fm.
Tambor Fm.Arcabuco Fm.Cumbre Fm.
Sources

See also

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

References

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

Bibliography

  • 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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