Hondita Formation

The Hondita Formation ( es, Formación Hondita, Ksh) is a fossiliferous geological formation of the Upper Magdalena Valley (VSM) and surrounding Central and Eastern Ranges of the Colombian Andes, extending from Cundinamarca in the north to Huila and easternmost Tolima in the south. The lowermost unit of the Güagüaquí Group, a sequence of sandy limestones and shales, dates to the Late Cretaceous period; Turonian epoch, and has a maximum thickness of .

Fossils of '' Yaguarasaurus columbianus'', said to be found in the time-equivalent La Frontera Formation (listed as "La Frontera Member"), were actually recovered from the Hondita Formation as the stratigraphic unit present in the Quebradas El Ocal and Itaibe, Huila.

Etymology

The formation was named in 1966 by De Porta, named after Quebrada Hondita in Piedras, Tolima.Acosta & Ulloa, 2002, p.23

Description

Lithologies

The Hondita Formation is characterised by a sequence of sandy limestones and shales with calcareous concretions up to in diameter.Acosta & Ulloa, 2002, p.24 The formation has provided fossils of '' Pachyrhizodus etayoi'',Páramo, 2001, p.68 '' Acanthoceras sp.'', '' Rhynchostreon sp.'' near Aipe, Huila.Patarroyo, 2011

Stratigraphy and depositional environment

The Hondita Formation is the lowermost unit of the Güagüaquí Group. It is overlain by the Loma Gorda Formation and its base has not been observed. The age has been estimated on the basis of ammonites to be Turonian. Stratigraphically, the formation is time equivalent with the lower parts of the Chipaque, La Luna and La Frontera Formations.Acosta & Ulloa, 2002, p.22 The formation was deposited in a relative highstand sequence with an oceanic oxygen depletion event, sharply marked in Colombia and characterised by the appearance of calcareous concretions with a thick pyrite rim.Villamil, 2012, p.173

''Yaguarasaurus''

Fossils of '' Yaguarasaurus columbianus'' were described as coming from the "La Frontera Member", part of the "Villeta Formation", in the Quebrada El Ocal, southwest of Neiva, Huila,''Yaguarasaurus columbianus''
at Fossilworks.org and in the Quebrada Itaibe southwest of Neiva,Páramo Fonseca, 2000, p.124 although in these areas the Hondita Formation is mapped.Plancha 344, 1999Plancha 345, 1999

Outcrops

The type locality of the Hondita Formation is located in Piedras, Tolima. Other outcrops of the Hondita Formation have been noted east of the Magdalena River northeast of Honda,Plancha 207, 2010 west of Nariño,Plancha 245, 1999 west across the Magdalena River in San Luis, Tolima,Plancha 264, 2002 between the Tetuán and Saldaña Rivers west of Coyaima and east and west of Ataco,Plancha 282, 1993 to the east of the Prado River reservoir,Plancha 283, 2009 north and west of Aipe,Plancha 302, 1993 surrounding Alpujarra, Tolima,Plancha 303, 2002 south of Palermo, Huila, displaced by the Baché Fault,Plancha 323, 1998 east of Iquira,Plancha 344, 1999 north of Yaguará,Plancha 345, 1999 south of La Plata where the formation is cut by the Itaibe Fault,Plancha 366, 1998 a small patch east of Gigante, Huila,Plancha 367, 2003 northwest and northeast of San Agustín,Plancha 388, 2002 and north of Timaná surrounding the Magdalena River.Plancha 389, 2003

Regional correlations

See also

: Geology of the Eastern Hills
: Geology of the Ocetá Páramo
: Geology of the Altiplano Cundiboyacense
: Geology of the Middle Magdalena Valley

References

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Maps

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External links

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{{Paleontology in Colombia, state=expanded

Geologic formations of Colombia
Cretaceous Colombia
Upper Cretaceous Series of South America
Turonian Stage
Limestone formations
Shale formations
Open marine deposits
Fossiliferous stratigraphic units of South America
Paleontology in Colombia
Formations
Formations
Formations
Magdalena River