The Cacho Formation (Spanish: Formación Cacho, E1C, Tpc, Tec) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly sandstone formation with thin intercalated beds of shales dates to the Paleogene period; Middle to Late Paleocene epochs, and has a maximum thickness of 400 metres (1,300 ft).
| Cacho Formation | |
|---|---|
| Stratigraphic range: Mid-Late Paleocene ~ | |
| Type | Geological formation |
| Underlies | Bogotá Formation |
| Overlies | Guaduas Formation |
| Thickness | 50–400 m (160–1,310 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Shale |
| Location | |
| Coordinates | 4°35′11.4″N 74°14′25.8″W / 4.586500°N 74.240500°W |
| Region | Bogotá savanna Altiplano Cundiboyacense Eastern Ranges Andes |
| Country |  Colombia |
| Type section | |
| Named by | Julivert |
| Location | Soacha |
| Year defined | 1963 |
| Coordinates | 4°35′11.4″N 74°14′25.8″W / 4.586500°N 74.240500°W |
| Region | Cundinamarca |
| Country | Colombia |
Definition
editThe formation was first described by Hubach in 1931 and 1957 and named by Campbell in 1962 and Julivert in 1963.[1][2]
Description
editLithologies
editThe Cacho Formation consists of white, yellow and reddish fine to coarse cross-bedded sandstones in thick banks intercalated with reddish and grey shales.[1][3]
Stratigraphy and depositional environment
editThe 50 to 400 metres (160 to 1,310 ft) thick Cacho Formation overlies the Guaduas Formation and is overlain by the Bogotá Formation.[3] The age has been estimated to be Late Paleocene, based on paleoflora studied by Thomas van der Hammen in 1957. The formation is laterally equivalent to the Lower Socha and Barco Formations.[4]
Outcrops
edit
The Cacho Formation is apart from its type locality in Soacha, found in the Eastern Hills of Bogotá, and many other locations in the Eastern Ranges up until the south of Boyacá.[2] The synclinals of the Río Frío, Checua-Lenguazaque, Sesquilé, Sisga, Subachoque, Teusacá, Siecha, and the anticlinal of Guatavita are composed of the Cacho Formation.[1]
See also
edit
References
editBibliography
edit- 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 2017-03-29
- Guerrero Uscátegui, Alberto Lobo (1992), Geología e Hidrogeología de Santafé de Bogotá y su Sabana, Sociedad Colombiana de Ingenieros, pp. 1–20
- Montoya Arenas, Diana María; Reyes Torres, Germán Alfonso (2005), Geología de la Sabana de Bogotá, INGEOMINAS, pp. 1–104
Maps
edit- Fuquen M., Jaime A; Osorno M, José F. (2009), Plancha 190 - Chiquinquirá - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
- Montoya, Diana María; Reyes, Germán (2009), Plancha 209 - Zipaquirá - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
- Terraza, Roberto; Moreno, Giovanni; Buitrago, José A.; Pérez, Adrián; Montoya, Diana María (2010), Plancha 210 - Guateque - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
- Buitrago, José Alberto; Terraza M., Roberto; Etayo, Fernando (1998), Plancha 228 - Santafé de Bogotá Noreste - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
External links
edit- Gómez, J.; Montes, N.E.; Nivia, Á.; Diederix, H. (2015), Plancha 5-09 del Atlas Geológico de Colombia 2015 – escala 1:500,000, Servicio Geológico Colombiano, p. 1, retrieved 2017-03-16