Chorrera Formation
Etymology
The formation was defined by Helmens and Van der Hammen in 1995 after the La Chorrera waterfall in Subachoque.
Description
Lithologies
The Chorrera Formation consists of coarse to very coarse conglomerates.
Stratigraphy and depositional environment
The Chorrera Formation unconformably overlies the Late Cretaceous Guadalupe Group. The formation is overlain by the Pleistocene Subachoque Formation. The age of the Chorrera Formation has been estimated to be Late Pliocene based on its stratigraphical position. The depositional environment is characterised by alluvial fans formed during the main phase of tectonic uplift of the Eastern Ranges in the Late Pliocene. Dutch geologist Salomon Kroonenberg, who studied the Neogene uplift of the Eastern Andes in Colombia, defines the main stage of uplift between six and four million years ago. Other Dutch geologists Helmens, Van der Hammen and Hooghiemstra have pushed back this uplift phase to between 4.5 and 3 Ma. The facies origin of the Chorrera Formation is comparable to the Marichuela Formation, outcropping on the eastern edge of the Bogotá savanna, yet different in stratigraphic position. The deposition of sediments of the Chorrera Formation is time-equivalent with the explosive phase of the Paipa–Iza volcanic complex, active between 4.7 and 3.6 Ma, and the Miocene to Late Pliocene Tilatá Formation.
Outcrops
The Chorrera Formation is found at its type locality in the synclinal of the Río Frío, east of Subachoque, Cundinamarca.
See also
References
Bibliography
- Molnar, Peter (2004), "Late Cenozoic increase in accumulation rates of terrestrial sediment", Annual Review of Earth and Planetary Sciences, 32: 67–89, doi:10.1146/annurev.earth.32.091003.143456
- Monsalve, Maria Luisa; Rojas, Nadia R.; Velandia P., Francisco A.; Pintor, Iraida; Martínez, Lina Fernanda (2011), "Caracterización geológica del cuerpo volcánico de Iza, Boyacá - Colombia" (PDF), Boletín de Geología, 33: 117–130, retrieved 2017-02-25
- Montoya Arenas, Diana María; Reyes Torres, Germán Alfonso (2005), Geología de la Sabana de Bogotá, INGEOMINAS, pp. 1–104
External links
- 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