Hiló Formation

The Hiló Formation (, 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 . 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.Acosta & Ulloa, 2002, p.44

Description Lithologies The Hiló Formation with a measured thickness of , 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.Acosta & Ulloa, 2001, p.16 The formation has been deposited in an open platform setting. The deposition is represented by a maximum flooding surface 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 at Fossilworks.orgOlini Creek 3 at Fossilworks.orgOlini Creek 6 at Fossilworks.orgOlini Creek 8 at Fossilworks.orgOlini Creek 9 at Fossilworks.orgOlini Creek 13 at Fossilworks.orgOlini Creek 15 at Fossilworks.orgOlini Creek 34 at Fossilworks.orgOlini Creek 39 at Fossilworks.orgOlini Creek 40 at Fossilworks.orgOlini Creek 47 at Fossilworks.orgOlini Creek 48 at Fossilworks.orgOlini Creek 54 at Fossilworks.orgOlini Creek 58 at Fossilworks.orgOlini Creek 59 at Fossilworks.orgOlini Creek 65 at Fossilworks.orgOlini Creek 100 at Fossilworks.orgOlini Creek 101 at Fossilworks.orgOlini Creek 106 at Fossilworks.orgOlini Creek 108 at Fossilworks.orgOlini Creek 115 at Fossilworks.orgOlini Creek 122 at Fossilworks.org

Outcrops

The Hiló Formation is apart from its type locality along the road from Apulo to Anapoima, found just east of Viotá, Cundinamarca,Plancha 246, 1998 and in the department of Tolima. West of Guayabal de Síquima, the formation is offset by the Vianí Fault.Plancha 227, 1998

Hiló Formation

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