The Marichuela Formation ( es, Formación Marichuela, N_1m) is a

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

of the Bogotá savanna, Altiplano Cundiboyacense, Eastern Ranges of the

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. The formation consists of coarse to very coarse conglomerates. The Marichuela Formation dates to the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

period;

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

Early Pliocene Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

epochs, and has a maximum thickness of .

Etymology

The formation was defined by Helmens and Van der Hammen in 1995 and named after the Marichuela neighbourhood of

Usme Usme is the 5th locality of the Capital District of Bogotá, capital city of Colombia. Usme is located in the south of Bogotá, bordering to the north the localities of San Cristóbal, Rafael Uribe Uribe and Tunjuelito, to the west the locali ...

.Montoya & Reyes, 2005, p.65 Part of the Marichuela Formation had been included in the Conos de Tunjuelo, defined by Julivert in 1961.Suna Hisca, s.a., p.45

Description

Lithologies

The Marichuela Formation consists of coarse to very coarse conglomerates.

Stratigraphy and depositional environment

The Marichuela Formation unconformably overlies the Cretaceous rocks of the

Guadalupe Group The Guadalupe Group ( es, Grupo Guadalupe, K2G, Ksg) is a geological group of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The group, a sequence of shales and sandstones, is subdivided into three formations; Arenisca Dur ...

. The age has been estimated to be

.Montoya & Reyes, 2005, p.67 The depositional environment has been interpreted as alluvial fans, caused by earthquakes or heavy rains.Montoya & Reyes, 2005, p.66

Outcrops

The Marichuela Formation is apart from its type locality in the

Synclinal, the valley of the

Tunjuelo River The Tunjuelo or Tunjuelito River is a river on the Bogotá savanna and a left tributary of the Bogotá River. The river, with a length of originates in the Sumapaz Páramo and flows northward through the Usme Synclinal to enter the Colombian capit ...

, found in the synclinals of Neusa, Sisga and La Calera.

Regional correlations

Notes

References

Bibliography

* *

Maps

External links

* {{cite LSA , last=Gómez , first=J. , last2=Montes , first2=N.E. , last3=Nivia , first3=Á. , last4=Diederix , first4=H. , year=2015 , title=Plancha 5-09 del Atlas Geológico de Colombia 2015 – escala 1:500,000 , url=https://www.researchgate.net/publication/309533589_Plancha_5-09_del_Atlas_Geologico_de_Colombia_2015 , publisher=

Servicio Geológico Colombiano The Colombian Geological Survey (CGS) ( es, Servicio Geológico Colombiano; formerly known as INGEOMINAS) is a scientific agency of the Colombian government in charge of contributing to the socioeconomic development of the nation through research ...

, pages=1 , accessdate=2017-03-16 Geologic formations of Colombia Neogene Colombia Messinian Tortonian Miocene Series of South America Pliocene Series of South America Montehermosan Huayquerian Conglomerate formations Alluvial deposits Formations Geography of Cundinamarca Department Geography of Bogotá