The Fómeque Formation ( es, Formación Fómeque, Kif) 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

Altiplano Cundiboyacense The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. The altiplano corresponds to the ancient territory of the Muisca. The Alti ...

Eastern Ranges The Eastern Ranges is an Australian rules football team in the NAB League, the Victorian statewide under-18s competition. The club is a founding member of the competition (1992) and has produced several players for the Australian Football Leagu ...

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 predominantly organic shale formation dates to the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period;

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded ...

to Late Aptian epochs and has a maximum thickness of .

Etymology

The formation was defined and named in 1957 by Hubach after

Fómeque Fómeque is a municipality and town of Colombia in the Departments of Colombia, department of Cundinamarca Department, Cundinamarca. Municipalities of Cundinamarca Department {{Cundinamarca-geo-stub ...

, Cundinamarca.Acosta & Ulloa, 2002, p.52

Description

Lithologies

The Fómeque Formation has a maximum thickness of , and is characterised by a sequence of pyritic

organic shale Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product o ...

s, with

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

s and

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

banks intercalated in the formation. The Fómeque Formation contains high values of TOC.Acosta & Ulloa, 2002, p.53 Fossils of '' Acarthohoplites sp.'', '' Melchionites sp.'', '' Nicklesia sp.'', '' Olcostephanus sp.'', '' Pulchellia sp.'' have been found in the formation.Caicedo et al., 2002, p.29

Stratigraphy and depositional environment

The Fómeque Formation overlies the Las Juntas Formation and is overlain by the

Une Formation The Une Formation ( es, Formación Une, Kiu) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly sandstone formation dates to the Middle Cretaceous period; Albian to Cenomanian epoc ...

. The age has been estimated to be

to Late Aptian. Stratigraphically, the formation is time equivalent with the Mercedes Formation. The formation has been deposited in a shallow marine

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

Outcrops

The Fómeque Formation is apart from its type locality, found in other parts of the Eastern Ranges.

Regional correlations

Notes

References

Bibliography

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Maps

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External links

* {{DEFAULTSORT:Fomeque Formation Geologic formations of Colombia Cretaceous Colombia Lower Cretaceous Series of South America Barremian Stage Aptian Stage Shale formations Shallow marine deposits Source rock formations Mining in Colombia Formations Geography of Cundinamarca Department Geography of Boyacá Department