The Hiló Formation ( es, Formación Hiló, Kih) 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

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

formation dates to the

Middle Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period; Late Albian to Early Cenomanian epochs and has a measured thickness at its type section of . The fossiliferous formation has provided a great abundance of

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

s and other marine species.

Etymology

The formation was defined and named in 1931 by Hubach after the Caserío Boquerón de Hiló in

Anapoima Anapoima () is a Colombian municipality in the department of Cundinamarca located from Bogotá. History The first inhabitants of the region were the Anapoymas Indians of the Panche nation. Between Tocaima and Tena there existed only small in ...

.Acosta & Ulloa, 2002, p.44

Description

Lithologies

The Hiló Formation with a measured thickness of , is characterised by a sequence of pyritic organic shales,

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

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s, with

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.

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 Une is a municipality and town of Colombia in the Eastern Province, Cundinamarca, Eastern Province, part of the Departments of Colombia, department of Cundinamarca Department, Cundinamarca. The urban centre is located at an altitude of at a dista ...

and Pacho Formations.Acosta & Ulloa, 2001, p.16 The formation has been deposited in an

open Open or OPEN may refer to: Music * Open (band), Australian pop/rock band * The Open (band), English indie rock band * ''Open'' (Blues Image album), 1969 * ''Open'' (Gotthard album), 1999 * ''Open'' (Cowboy Junkies album), 2001 * ''Open'' (YF ...

platform setting. The deposition is represented by a

maximum flooding surface In sequence stratigraphy Sequence stratigraphy is a branch of geology, specifically a branch of stratigraphy, that attempts to discern and understand historic geology through time by subdividing and linking sedimentary deposits into unconformity bo ...

and pelagic to hemipelagic conditions.Villamil, 2012, p.164

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.Olini Creek 1
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Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

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Outcrops

The Hiló Formation is apart from its type locality along the road from

Apulo Apulo (previously called ''Rafael Reyes Municipality'') is a Colombian town and municipality in the Cundinamarca Department. Municipalities of Cundinamarca Department {{Cundinamarca-geo-stub ...

, found just east of Viotá, Cundinamarca,Plancha 246, 1998 and in the

department Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

of Tolima. West of Guayabal de Síquima, the formation is offset by the Vianí Fault.Plancha 227, 1998

Regional correlations

References

Bibliography

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Maps

* * * {{DEFAULTSORT:Hilo Formation Geologic formations of Colombia Cretaceous Colombia Lower Cretaceous Series of South America Upper Cretaceous Series of South America Albian Stage Cenomanian Stage Shale formations Open marine deposits Fossiliferous stratigraphic units of South America Paleontology in Colombia Formations Formations Formations Muysccubun