Earth:Hondita Formation

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Hondita Formation
Stratigraphic range: Turonian
~93–90 Ma
TypeGeological formation
Unit ofGüagüaquí Group
UnderliesLoma Gorda Formation
Overliesnot observed
Thicknessup to 90 m (300 ft)
Lithology
PrimarySandy limestone, shale
OtherCalcareous concretions
Location
Coordinates [ ⚑ ] : 4°30′47″N 74°52′32″W / 4.51306°N 74.87556°W / 4.51306; -74.87556
Paleocoordinates [ ⚑ ] 3°00′S 52°00′W / 3.0°S 52.0°W / -3.0; -52.0
RegionUpper Magdalena Valley, Central & Eastern Ranges, Andes
Country Colombia
Type section
Named forQuebrada Hondita
Named byDe Porta
LocationPiedras, Tolima
Year defined1966
Coordinates [ ⚑ ] 4°30′47″N 74°52′32″W / 4.51306°N 74.87556°W / 4.51306; -74.87556
RegionCundinamarca, Huila, Tolima
Country Colombia
Blakey 090Ma - COL.jpg
Paleogeography of Northern South America
90 Ma, by Ron Blakey

The Hondita Formation (Spanish: 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 90 metres (300 ft).

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.[1]

Description

Lithologies

The Hondita Formation is characterised by a sequence of sandy limestones and shales with calcareous concretions up to 2 metres (6.6 ft) in diameter.[2] The formation has provided fossils of Pachyrhizodus etayoi,[3] Acanthoceras sp., Rhynchostreon sp. near Aipe, Huila.[4]

Stratigraphy and depositional environment

The Hondita Formation is the lowermost unit of the Güagüaquí Group.[1] 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.[2] Stratigraphically, the formation is time equivalent with the lower parts of the Chipaque, La Luna and La Frontera Formations.[5] 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.[6]

Yaguarasaurus

Fossils of Yaguarasaurus columbianus were described as coming from the "La Frontera Member", part of the "Villeta Formation", in the Quebrada El Ocal, 26 kilometres (16 mi) southwest of Neiva, Huila,[7][8] and in the Quebrada Itaibe 78 kilometres (48 mi) southwest of Neiva,[9] although in these areas the Hondita Formation is mapped.[10][11]

Outcrops

Hondita Formation is located in Tolima Department
Hondita Formation
Type locality of the Hondita Formation in Tolima

The type locality of the Hondita Formation is located in Piedras, Tolima.[1] Other outcrops of the Hondita Formation have been noted east of the Magdalena River northeast of Honda,[12] west of Nariño,[13] west across the Magdalena River in San Luis, Tolima,[14] between the Tetuán and Saldaña Rivers west of Coyaima and east and west of Ataco,[15] to the east of the Prado River reservoir,[16] north and west of Aipe,[17] surrounding Alpujarra, Tolima,[18] south of Palermo, Huila, displaced by the Baché Fault,[19] east of Iquira,[10] north of Yaguará,[11] south of La Plata where the formation is cut by the Itaibe Fault,[20] a small patch east of Gigante, Huila,[21] northwest and northeast of San Agustín,[22] and north of Timaná surrounding the Magdalena River.[23]

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
C-Class article Geology of the Middle Magdalena Valley

References

  1. 1.0 1.1 1.2 Acosta & Ulloa, 2002, p.23
  2. 2.0 2.1 Acosta & Ulloa, 2002, p.24
  3. Páramo, 2001, p.68
  4. Patarroyo, 2011
  5. Acosta & Ulloa, 2002, p.22
  6. Villamil, 2012, p.173
  7. 'Yaguarasaurus columbianus' in the Paleobiology Database
  8. Yaguarasaurus columbianus at Fossilworks.org
  9. Páramo Fonseca, 2000, p.124
  10. 10.0 10.1 Plancha 344, 1999
  11. 11.0 11.1 Plancha 345, 1999
  12. Plancha 207, 2010
  13. Plancha 245, 1999
  14. Plancha 264, 2002
  15. Plancha 282, 1993
  16. Plancha 283, 2009
  17. Plancha 302, 1993
  18. Plancha 303, 2002
  19. Plancha 323, 1998
  20. Plancha 366, 1998
  21. Plancha 367, 2003
  22. Plancha 388, 2002
  23. Plancha 389, 2003

Bibliography

Maps

External links