Conejo Formation
{{Short description|Fossiliferous geological formation in the Eastern Ranges of the Colombian Andes}}
{{Infobox rockunit
| name = Conejo Formation
| period = Santonian
| age = Turonian-Santonian
~{{fossil range|90|83.6}}
| image =
| imagesize =
| caption =
| type = Geological formation
| prilithology = Sandstone, shale
| otherlithology = Limestone
| unitof = Villeta Group
| subunits =
| underlies = Guadalupe Group
| overlies = La Frontera Formation
| thickness = up to {{convert|1022|m|ft|abbr=on}}
| area =
| map = Blakey 090Ma - COL.jpg
| map_caption = Paleogeography of Northern South America
90 Ma, {{small|by Ron Blakey}}
| location =
| coordinates = {{coord|5|35|40.7|N|73|12|59.6|W|display=inline,title}}
| region = Altiplano Cundiboyacense
Eastern Ranges, Andes
| country = Colombia
| extent =
| namedfor = El Conejo Hill
| namedby = Renzoni
| year_ts = 1981
| coordinates_ts = {{coord|5|35|40.7|N|73|12|59.6|W|display=inline}}
| paleocoordinates_ts =
| region_ts = Cundinamarca, Boyacá
| country_ts = Colombia
| thickness_ts =
}}
The Conejo Formation ({{langx|es|Formación Conejo}}, K2C, Kscn) is a fossiliferous geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The uppermost unit of the Villeta Group, a sequence of shales and sandstones dates to the Late Cretaceous period; Turonian, Coniacian and Santonian epochs, and has a maximum thickness of {{convert|1022|m|ft}}.
Etymology
The formation was named in 1967 and published in 1981 by Renzoni, named after El Conejo Hill in Pontezuela, Toca, Boyacá, west of the Copa Reservoir.Montoya & Reyes, 2005, p.29
Description
= Lithologies =
The Conejo Formation is characterised by a sequence of calcareous sandstones, containing ammonites, shales and the uppermost part sandstone and limestone banks.Montoya & Reyes, 2005, p.30 In the Conejo Formation, fossils of Protopholoe colombiana, Archaeglobigerina blowi, Dicarinella concavata, Dicarinella primitiva, Sigalitruncana sigali, Marginotruncana sp. ct. M. renzi, Marginotruncana angusticarenata, Marginotruncana sp. cf. M.sinuosa, Rosita tornicata, Heterohelix globulosa, Heterohelix reussi, Whiteinella inornata, Hedbergella sp., and the ammonites Gloriaceras correai, Protexamites cucaitaense and Codazziceras scheibei have been found.Luque et al., 2015Tchegliakova & Pérez, 1995Acosta & Ulloa, 2002, p.48
= Stratigraphy and depositional environment =
The Conejo Formation is the uppermost unit of the Villeta Group. It overlies the La Frontera Formation and is overlain by the Guadalupe Group. The age has been estimated on the basis of ammonites to be ranging from Turonian to Santonian. Stratigraphically, the lower part of the formation is time equivalent with the upper part of the Chipaque,Montoya & Reyes, 2005, p.34 and Loma Gorda Formations.Acosta & Ulloa, 2002, p.22
Outcrops
{{Location map | Altiplano Cundiboyacense
| width = 250
| lat_deg = 5.594641
| lon_deg = -73.216546
| label =
| float = left
| position = right
| mark = Green pog.svg
| marksize = 12
| caption = Type locality of the Conejo Formation on the Altiplano Cundiboyacense
}}
The type locality of the Conejo Formation is located close to El Conejo Hill in Pontezuela, Toca, Boyacá.Acosta & Ulloa, 2001, p.43 Other outcrops of the Conejo Formation have been noted in Cucaita, the urban areas of Boyacá and Ventaquemada, around the Puente de Boyacá, south of Pesca, west of Siachoque,Plancha 191, 1998 surrounding Chiquinquirá and Ubaté,Plancha 190, 2009 between Chivatá and Oicatá, east of Paipa,Planchas 171 & 191, 2005 west of Tibacuy,Plancha 246, 1998 north and south of Albán, southeast of Cachipay, east of Anolaima, and San Antonio del Tequendama, Cundinamarca.Plancha 227, 1998
{{clear}}
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
References
{{reflist|20em}}
= Bibliography =
- {{citation |last1=Acosta |first1=Jorge E. |last2=Ulloa |first2=Carlos E. |year=2002 |title=Mapa geológico del Departamento de Cundinamarca 1:250,000 - Memoria Explicativa |publisher=INGEOMINAS |pages=1–108}}
- {{citation |last1=Acosta Garay |first1=Jorge |last2=Ulloa Melo |first2=Carlos E. |year=2001 |title=Geología de la Plancha 208 Villeta - 1:100,000 |url=http://aplicaciones1.sgc.gov.co/Bodega/i_vector/130/10/0100/20136/documento/pdf/0101201361101000.pdf |publisher=INGEOMINAS |pages=1–84 |accessdate=2017-03-16 }} {{Webarchive|url=https://web.archive.org/web/20170324084417/http://aplicaciones1.sgc.gov.co/Bodega/i_vector/130/10/0100/20136/documento/pdf/0101201361101000.pdf |date=2017-03-24 }}
- {{citation |last1=Luque |first1=Javier |last2=Hourdez |first2=Stéphane |last3=Vinn |first3=Olev |year=2015 |title=A new fossil bristle worm (Annelida: Polychaeta: Aphroditiformia) from the late Cretaceous of tropical America |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/new-fossil-bristle-worm-annelida-polychaeta-aphroditiformia-from-the-late-cretaceous-of-tropical-america/001779F49F6F5DA4DA99C472068B31E6 |journal=Journal of Paleontology |volume=89 |issue=2 |pages=257–261 |doi=10.1017/jpa.2014.22 |bibcode=2015JPal...89..257L |accessdate=2017-04-04|url-access=subscription }}
- {{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}}
- {{citation |last1=Tchegliakova |first1=Nadejda |last2=Pérez |first2=Vladimir |year=1995 |title=Registro de la Zona bioestratigrafica Dicarinella concavata (Foraminiferida) en el Extremo noroccidental de Suramerica (Colombia) |url=http://168.176.5.16/index.php/geocol/article/viewFile/31349/31355 |journal=Geología Colombiana |volume=19 |pages=131–143 |accessdate=2017-04-06}}
- {{citation |last=Villamil |first=Tomas |year=2012 |title=Chronology Relative Sea Level History and a New Sequence Stratigraphic Model for Basinal Cretaceous Facies of Colombia |publisher=Society for Sedimentary Geology (SEPM) |pages=161–216}}
== Maps ==
- {{citation |last1=Ulloa |first1=Carlos E |last2=Rodríguez |first2=Erasmo |year=2009 |title=Plancha 170 - Vélez - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QcGU2Z19qSDBTZ28 |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Renzoni |first1=Giancarlo |last2=Rosas |first2=Humberto |year=2009 |title=Plancha 171 - Duitama - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QVU40dC0wUzhzTkk |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Fuquen M. |first1=Jaime A |last2=Osorno M |first2=José F. |year=2009 |title=Plancha 190 - Chiquinquirá - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QVEYzMnV1ekNxTDQ |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Renzoni |first1=Giancarlo |last2=Rosas |first2=Humberto |author3-link=Fernando Etayo |last3=Etayo Serna |first3=Fernando |year=1998 |title=Plancha 191 - Tunja - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QQzhBTXNwUWJuUDg |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Ulloa |first1=Carlos |last2=Acosta |first2=Jorge |year=1998 |title=Plancha 208 - Villeta - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QMjhLeWJ0aU1Za1U |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Montoya |first1=Diana María |last2=Reyes |first2=Germán |year=2009 |title=Plancha 209 - Zipaquirá - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QYUdHRWFiN1JrVms |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Terraza |first1=Roberto |last2=Moreno |first2=Giovanni |last3=Buitrago |first3=José A. |last4=Pérez |first4=Adrián |last5=Montoya |first5=Diana María |year=2010 |title=Plancha 210 - Guateque - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QS1VHUTg1MEpNcHM |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Ulloa |first1=Carlos E |last2=Rodríguez |first2=Erasmo |last3=Acosta |first3=Jorge E. |year=1998 |title=Plancha 227 - La Mesa - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QR0k3cWk2aTlwbEk |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{citation |last1=Acosta |first1=Jorge E. |last2=Guatame |first2=Rafael |last3=Torres |first3=Oscar |last4=Solano |first4=Frank |year=1999 |title=Plancha 245 - Girardot - 1:100,000 |url=https://drive.google.com/open?id=0BwFQPMJEi17QUmhEQTdMNmcxT28 |publisher=INGEOMINAS |pages=1 |accessdate=2017-06-06}}
- {{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}}
- {{citation |last1=Velandia |first1=Francisco |last2=Cepeda |first2=Héctor |year=2005 |title=Planchas 171 & 191 - Geología sector del sur del municipio de Paipa (Boyacá) - 1:25,000 |publisher=INGEOMINAS}}
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:Upper Cretaceous Series of South America
Category:Fossiliferous stratigraphic units of South America