Conejo Formation
| Conejo Formation Stratigraphic range: Turonian-Santonian ~90–83.6 Ma |
|
|---|---|
| Type | Geological formation |
| Unit of | Villeta Group |
| Underlies | Guadalupe Group |
| Overlies | La Frontera Formation |
| Thickness | up to 1,022 m (3,353 ft) |
| Lithology | |
| Primary | Sandstone, shale |
| Other | Limestone |
| Location | |
| Coordinates | 5°35′40.7″N 73°12′59.6″W / 5.594639°N 73.216556°WCoordinates: 5°35′40.7″N 73°12′59.6″W / 5.594639°N 73.216556°W |
| Region |
Altiplano Cundiboyacense Eastern Ranges, Andes |
| Country |
 Colombia
|
| Type section | |
| Named for | El Conejo Hill |
| Named by | Renzoni |
| Location | , Boyacá |
| Year defined | 1981 |
| Coordinates | 5°35′40.7″N 73°12′59.6″W / 5.594639°N 73.216556°W |
| Region | Cundinamarca, Boyacá |
| Country |
Colombia
|
 Paleogeography of Northern South America 90 Ma, by Ron Blakey |
|
The Conejo Formation (Spanish: 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 1,022 metres (3,353 ft).
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.
The Conejo Formation is characterised by a sequence of calcareous sandstones, containing ammonites, shales and the uppermost part sandstone and limestone banks. 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.
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, and Loma Gorda Formations.
...
Wikipedia