The Simijaca Formation (Spanish: Formación Simijaca, K2S, Kss) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly mudstone formation dates to the Late Cretaceous period; Turonian and Cenomanian epochs, and has a maximum thickness of 693 metres (2,274 ft).

Simijaca Formation
Stratigraphic range: Cenomanian-Turonian
~100–90 Ma
TypeGeological formation
Unit ofVilleta Group
UnderliesLa Frontera Formation
OverliesChiquinquirá Sst., Churuvita Fm., Hiló Fm., Pacho Fm.
Thicknessup to 693 m (2,270 ft)
Lithology
PrimaryMudstone
OtherShale, sandstone, limestone
Location
Coordinates5°29′15″N 73°50′55″W / 5.48750°N 73.84861°W / 5.48750; -73.84861
RegionAltiplano Cundiboyacense
Eastern Ranges, Andes
Country Colombia
Type section
Named forSimijaca
Named byUlloa & Rodríguez
LocationSouth of Simijaca
Year defined1991
Coordinates5°29′15″N 73°50′55″W / 5.48750°N 73.84861°W / 5.48750; -73.84861
RegionCundinamarca, Boyacá
Country Colombia
Thickness at type section432 metres (1,420 ft)

Paleogeography of Northern South America
90 Ma, by Ron Blakey

Etymology

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The formation was defined and named in 1991 by Ulloa and Rodríguez after Simijaca, Cundinamarca.[1]

Description

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Lithologies

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The Simijaca Formation is characterised by a sequence of mudstones, grey and black shales with sandstone and limestone intercalations.[1][2]

Stratigraphy and depositional environment

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The Simijaca Formation conformably overlies the Chiquinquirá Sandstone, and the Hiló and Pacho Formations, and is overlain by the La Frontera Formation.[3] The age has been estimated to be Turonian,[1] or Cenomanian.[4] Stratigraphically, the formation is time equivalent with the Chipaque Formation.[5] The formation has been deposited in an open marine platform setting.[6] The deposition is represented by a maximum flooding surface.[7]

Outcrops

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Type locality of the Simijaca Formation on the Altiplano Cundiboyacense

The Simijaca Formation is apart from its type locality in the Quebrada Don Lope,[2] found at surface in the north of the Bogotá savanna, in the Tabio anticlinal, along the road Ubaté-Carmen de Carupa,[8] at the western and eastern flanks of the Aponsentos-Chiquinquirá Synclinal,[9] near Tena, south of Anolaima and Cachipay,[10] and between Anapoima and Granada.[11]

Regional correlations

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See also

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

References

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  1. ^ a b c Montoya & Reyes, 2005, p.21
  2. ^ a b Acosta & Ulloa, 2001, p.38
  3. ^ Acosta & Ulloa, 2001, p.32
  4. ^ Acosta & Ulloa, 2001, p.41
  5. ^ Montoya & Reyes, 2005, p.22
  6. ^ García González et al., 2009, p.209
  7. ^ Villamil, 2012, p.164
  8. ^ Montoya & Reyes, 2005, p.23
  9. ^ Plancha 190, 2009
  10. ^ Plancha 227, 1998
  11. ^ Plancha 246, 1998

Bibliography

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  • Acosta Garay, Jorge; Ulloa Melo, Carlos E. (2001), Geología de la Plancha 208 Villeta - 1:100,000 (PDF), INGEOMINAS, pp. 1–84, retrieved 2017-03-23
  • García González, Mario; Mier Umaña, Ricardo; Cruz Guevara, Luis Enrique; Vásquez, Mauricio (2009), Informe Ejecutivo - evaluación del potencial hidrocarburífero de las cuencas colombianas, Universidad Industrial de Santander, pp. 1–219
  • Montoya Arenas, Diana María; Reyes Torres, Germán Alfonso (2005), Geología de la Sabana de Bogotá, INGEOMINAS, pp. 1–104
  • 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

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