Usme Formation
{{short description|Geological formation in the Colombian Andes}}
{{other uses|Usme (disambiguation)}}
{{Infobox rockunit
| name = Usme Formation
| period = Oligocene
| age = Late Eocene-Early Oligocene
~{{fossil range|40|30}}
| image =
| imagesize =
| caption =
| type = Geological formation
| prilithology = Shale, sandstone, conglomerate
| otherlithology =
| unitof =
| subunits =
| underlies = Tilatá Formation
| overlies = Regadera Formation
| thickness = up to {{convert|300|m|ft|abbr=on}}
| area =
| map = Blakey 035Ma - COL.jpg
| map_caption = Paleogeography of Northern South America
35 Ma, {{small|by Ron Blakey}}
| location =
| coordinates = {{coord|4|21|40.3|N|74|07|50|W|display=inline,title}}
| region = Bogotá savanna, Altiplano Cundiboyacense
Eastern Ranges, Andes
| country = Colombia
| extent =
| namedfor = Usme
| namedby = Hubach
| year_ts = 1957
| coordinates_ts = {{coord|4|21|40.3|N|74|07|50|W|display=inline}}
| paleocoordinates_ts =
| region_ts = Cundinamarca
| country_ts = Colombia
| thickness_ts =
}}
The Usme Formation ({{langx|es|Formación Usme}}, Tsu, Teu) is a geological formation of the Bogotá savanna, Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of a lower part with predominantly shales with intercalated sandstone beds and an upper sequence with sandstones and conglomerates. The Usme Formation dates to the Neogene and Paleogene periods; Late Eocene to Early Oligocene epochs, and has a maximum thickness of {{convert|300|m|ft}}.
Etymology
The formation was defined by Hubach in 1957 and named after the locality of Usme, Bogotá.Montoya & Reyes, 2005, p.65
Description
= Lithologies =
The Usme Formation is subdivided into a lower sequence of shales with intercalated sandstones and an upper part of sandstones and conglomerates.
= Stratigraphy and depositional environment =
The Usme Formation unconformably overlies the Regadera Formation and is overlain by the Tilatá Formation.Guerrero Uscátegui, 1992, p.6 The age has been estimated, based on palynological data, to be Late Eocene to Early Oligocene. The depositional environment has been interpreted as marine with the upper part deposited in a deltaic setting.Bayona et al., 2010, p.7
Outcrops
{{Location map | Bogotá savanna
| width = 250
| lat_deg = 4.361195
| lon_deg = -74.130564
| label =
| float = left
| position = right
| mark = Orange pog.svg
| marksize = 12
| caption = Type locality of the Usme Formation to the south of the Bogotá savanna
}}
The Usme Formation is found in its type locality in the synclinal of Usme, the valley of the Tunjuelo River.
{{clear}}
Regional correlations
{{Stratigraphy of the Llanos Basin}}
See also
{{Portal|Colombia|Geology}}
:{{icon|FAC}} Geology of the Eastern Hills
:{{icon|B}} Geology of the Ocetá Páramo
:{{icon|C}} Geology of the Altiplano Cundiboyacense
Notes and references
= Notes =
{{reflist|group=note}}
= References =
{{reflist|30em}}
= Bibliography =
- {{citation |last1=Bayona |first1=Germán |last2=Montenegro |first2=Omar |last3=Cardona |first3=Agustín |last4=Jaramillo |first4=Carlos |last5=Lamus |first5=Felipe |last6=Morón |first6=Sara |last7=Quiroz |first7=Luiz |last8=Ruíz |first8=María C. |last9=Valencia and Mauricio Parra |first9=Victor |year=2010 |title=Estratigrafía, procedencia, subsidencia y exhumación de las unidades paleógenas en el Sinclinal de Usme, sur de la zona axial de la Cordillera Oriental - Stratigraphy, provenance, subsidence and exhumation of the Paleogene succession in the Usme Syncline, southern axial zone of the Eastern Cordillera |url=http://www.bdigital.unal.edu.co/24001/1/21100-118170-1-PB.pdf |journal=Geología Colombiana |volume=35 |pages=5–35 |accessdate=2017-03-16}}
- {{citation |last=Guerrero Uscátegui |first=Alberto Lobo |year=1992 |title=Geología e Hidrogeología de Santafé de Bogotá y su Sabana |publisher=Sociedad Colombiana de Ingenieros |pages=1–20}}
- {{citation |last1=Montoya Arenas |first1=Diana María |last2=Reyes Torres |first2=Germán Alfonso |year=2005 |title=Geología de la Sabana de Bogotá |publisher=INGEOMINAS |pages=1–104}}
== Maps ==
- {{citation |last1=Acosta |first1=Jorge E. |last2=Ulloa |first2=Carlos E. |year=1998 |title=Plancha 246 - Fusagasugá - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QNkY5UEloZU9pdEk |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
External links
- {{citation |last1=Gómez |first1=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 |publisher=Servicio Geológico Colombiano |pages=1 |accessdate=2017-03-16}}
Category:Geologic formations of Colombia
Category:Eocene Series of South America