Geological formation in the Colombian Andes
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] 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. ?Syncyclonema sp. [ 4] [ 5] [ 6] [ 7] [ 8] [ 9] [ 10] [ 11] [ 12] [ 13] [ 14] [ 15] [ 16] [ 17] [ 18] [ 19] [ 20] [ 21] [ 22] [ 23] [ 24] [ 25]
Outcrops
Type locality of the Hiló Formation to the west of the Bogotá savanna
The Hiló Formation is apart from its type locality along the road from Apulo to Anapoima , found just east of Viotá , Cundinamarca,[ 26] 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] Guayabal de Síquima , the formation is offset by the Vianí Fault.[ 27]
Regional correlations
See also
Geology of the Eastern Hills Geology of the Ocetá Páramo Geology of the Altiplano Cundiboyacense
References
Bibliography
Acosta Garay, Jorge E.; Ulloa Melo, Carlos E. (2002), Mapa Geológico del Departamento de Cundinamarca - 1:250,000 - Memoria explicativa INGEOMINAS , pp. 1–108, retrieved 2017-04-26 Acosta Garay, Jorge; Ulloa Melo, Carlos E. (2001), Geología de la Plancha 208 Villeta - 1:100,000 (PDF) , INGEOMINAS , pp. 1–84, archived from the original (PDF) on 2017-03-24, retrieved 2017-04-04 Villamil, Tomas (2012), Chronology Relative Sea Level History and a New Sequence Stratigraphic Model for Basinal Cretaceous Facies of Colombia , Society for Sedimentary Geology (SEPM), pp. 161–216
Maps
Ulloa, Carlos; Acosta, Jorge (1998), Plancha 208 - Villeta - 1:100,000 INGEOMINAS , p. 1, retrieved 2017-06-06 Ulloa, Carlos E.; Rodríguez, Erasmo; Acosta, Jorge E. (1998), Plancha 227 - La Mesa - 1:100,000 INGEOMINAS , p. 1, retrieved 2017-06-06 Acosta, Jorge E.; Ulloa, Carlos E. (1998), Plancha 246 - Fusagasugá - 1:100,000 INGEOMINAS , p. 1, retrieved 2017-06-06
