Earth:Fómeque Formation

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Short description: Geological formation in the Colombian Andes
Fómeque Formation
Stratigraphic range: Barremian-Late Aptian
~126–113 Ma
TypeGeological formation
Unit ofVilleta Group
UnderliesUne Formation
OverliesLas Juntas Formation
Thicknessup to 1,200 m (3,900 ft)
Lithology
PrimaryOrganic shale
OtherLimestone, sandstone
Location
Coordinates [ ⚑ ] : 4°27′07″N 74°03′20″W / 4.45194°N 74.05556°W / 4.45194; -74.05556
RegionAltiplano Cundiboyacense
Eastern Ranges, Andes
Country Colombia
Type section
Named forFómeque
Named byHubach
LocationFómeque
Year defined1957
Coordinates [ ⚑ ] 4°27′07″N 74°03′20″W / 4.45194°N 74.05556°W / 4.45194; -74.05556
RegionCundinamarca, Boyacá
Country Colombia
Blakey 120Ma - COL.jpg
Paleogeography of Northern South America
120 Ma, by Ron Blakey

The Fómeque Formation (Spanish: Formación Fómeque, Kif) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly organic shale formation dates to the Early Cretaceous period; Barremian to Late Aptian epochs and has a maximum thickness of 1,200 metres (3,900 ft).

Etymology

The formation was defined and named in 1957 by Hubach after Fómeque, Cundinamarca.[1]

Description

Lithologies

The Fómeque Formation has a maximum thickness of 1,200 metres (3,900 ft), and is characterised by a sequence of pyritic organic shales, with limestones and sandstone banks intercalated in the formation. The Fómeque Formation contains high values of TOC.[2] Fossils of Acarthohoplites sp., Melchionites sp., Nicklesia sp., Olcostephanus sp., Pulchellia sp. have been found in the formation.[3]

Stratigraphy and depositional environment

The Fómeque Formation overlies the Las Juntas Formation and is overlain by the Une Formation. The age has been estimated to be Barremian to Late Aptian. Stratigraphically, the formation is time equivalent with the Mercedes Formation. The formation has been deposited in a shallow marine environment.[2]

Outcrops

Lua error in Module:Location_map at line 522: Unable to find the specified location map definition: "Module:Location map/data/Bogotá savanna" does not exist. The Fómeque Formation is apart from its type locality, found in other parts of the Eastern Ranges.

Regional correlations

See also

Featured article candidate Geology of the Eastern Hills
B-Class article Geology of the Ocetá Páramo
C-Class article Geology of the Altiplano Cundiboyacense

Notes

References

  1. Acosta & Ulloa, 2002, p.52
  2. 2.0 2.1 Acosta & Ulloa, 2002, p.53
  3. Caicedo et al., 2002, p.29

Bibliography

Maps

External links