Earth:Hiló Formation

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Short description: Geological formation in the Colombian Andes
Hiló Formation
Stratigraphic range: Late Albian-Early Cenomanian
~102–98 Ma
TypeGeological formation
Unit ofVilleta Group
UnderliesSimijaca Formation
OverliesCapotes Formation
Thicknessmore than 470 metres (1,540 ft)
Lithology
PrimaryShale
OtherSandstone, limestone, siltstone
Location
Coordinates [ ⚑ ] : 4°47′28″N 74°30′49″W / 4.79111°N 74.51361°W / 4.79111; -74.51361
RegionAltiplano Cundiboyacense
Eastern Ranges, Andes
Country Colombia
Type section
Named forCaserío Boquerón de Hiló
Named byHubach
LocationApulo-Anapoima
Year defined1931
Coordinates [ ⚑ ] 4°47′28″N 74°30′49″W / 4.79111°N 74.51361°W / 4.79111; -74.51361
Paleocoordinates [ ⚑ ] 0°36′N 45°18′W / 0.6°N 45.3°W / 0.6; -45.3
RegionCundinamarca, Tolima
Country Colombia
Thickness at type section470 m (1,540 ft)
Blakey 105Ma - COL.jpg
Paleogeography of Northern South America
105 Ma, by Ron Blakey

The Hiló Formation (Spanish: Formación Hiló, Kih) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly shale formation dates to the Middle Cretaceous period; Late Albian to Early Cenomanian epochs and has a measured thickness at its type section of 470 metres (1,540 ft). The fossiliferous formation has provided a great abundance of ammonites and other marine species.

Etymology

The formation was defined and named in 1931 by Hubach after the Caserío Boquerón de Hiló in Anapoima.[1]

Description

Lithologies

The Hiló Formation with a measured thickness of 470 metres (1,540 ft), is characterised by a sequence of pyritic organic shales, limestones and siltstones, with sandstone banks intercalated in the formation.

Stratigraphy and depositional environment

The Hiló Formation overlies the Capotes Formation and is overlain by the Simijaca Formation. The age has been estimated to be Late Albian to Early Cenomanian. Stratigraphically, the formation is time equivalent with the Une and Pacho Formations.[2] The formation has been deposited in an open platform setting. The deposition is represented by a maximum flooding surface and pelagic to hemipelagic conditions.[1][3]

Fossil content

Fossils of Actinoceramus munsoni, Actinoceramus aff. subsulcatiformis, Beudanticeras cf. rebouli, Desmoceras latidorsatum, Eubrancoceras cf. aegoceratoides, Exogyra aff. texana, Goodhallites aguilerae, Inoceramus anglicus, Inoceramus cf. cadottensis, Inoceramus aff. dunveganensis, Inoceramus aff. etheridgei, Inoceramus cf. ewaldi, Inoceramus aff. irenensis, Inoceramus prefragilis, Inoceramus cf. richensis, Lyelliceras pseudolyelli, Mojsisovicsia evansi, Mortoniceras arietiforme, Neocomiceramus neocomiensis, Neoharpoceras hugardianum, Oxytropidoceras intermedium, Oxytropidoceras karsteni, Oxytropidoceras laraense, Oxytropidoceras multicostatum, Oxytropidoceras nodosum, Oxytropidoceras peruvianum, ?Oxytropidoceras robustum, Oxytropidoceras venezolanum, Prolyelliceras gevreyi, Prolyelliceras prorsocurvatum, Puzio media, Tegoceras mosense, Acompsoceras sp., ?Bositra sp., Camptonectes sp., Entolium sp., Hamites sp., Hysteroceras sp., Mariella sp., Ostrea sp., Phelopteria sp., and ?Syncyclonema sp. have been found in the Hiló Formation.[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]

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 Hiló Formation is apart from its type locality along the road from Apulo to Anapoima, found just east of Viotá, Cundinamarca,[26] and in the department of Tolima.[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] West of Guayabal de Síquima, the formation is offset by the Vianí Fault.[27]

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

References

Bibliography

Maps