Huitrera Formation
Stratigraphic range: Early Eocene (Casamayoran)
TypeGeological formation
UnderliesCollón Curá Formation
OverliesAngostura Colorada Formation
ThicknessUp to 1,300 m (4,300 ft)
Lithology
PrimaryMudstone, sandstone
OtherAndesites, dacitic & rhyolitic ignimbrites, volcanic breccias, tuffs & trachybasalts
Location
Coordinates41°00′S 71°12′W / 41.0°S 71.2°W / -41.0; -71.2
Approximate paleocoordinates43°30′S 61°12′W / 43.5°S 61.2°W / -43.5; -61.2
RegionNeuquén & Río Negro Provinces
CountryArgentina
ExtentNeuquén Basin
Type section
Named forCerro Huitrera
Named byRavazzoli & Sesana
Year defined1977
Huitrera Formation is located in Argentina
Huitrera Formation
Huitrera Formation (Argentina)

The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification.

The formation is together with the Reyhuau basalts part of the Pilcaniyeu Belt, a volcanic belt active in Paleocene to middle Eocene times.[1]

Description

The Huitrera Formation was first defined by Ravazzoli and Sesana in 1977. The name has been used to identify various volcaniclastic sequences, among others in the Ñirihuau fold-and-thrust belt.[2] The up to 1,300 metres (4,300 ft) thick formation comprises mudstones and sandstones deposited in a crater lake environment. Part of the formation comprises andesites, dacitic and rhyolitic ignimbrites, volcanic breccias, tuffs and trachybasalts.[3]

The formation was initially described as Late Eocene to Early Oligocene, but was later dated to 54.24 ± 0.45 Ma, meaning the Huitrera Formation is Ypresian, or in the SALMA classification, Casamayoran in age.

Fossil content

The following macrofossils were reported from the formation:[4]

The formation has also provided many pollen, analyzed in 2003 by Melendi et al.[12]

See also

References

  1. ↑ Fernández Paz et al., 2020
  2. ↑ Escosteguy & Franchi, 2010, p.420
  3. ↑ Prez & Massafero, 2013, p.228
  4. ↑ Huitrera Formation at Fossilworks.org
  5. ↑ Degrange, F. J.; Pol, D.; Puerta, P.; Wilf, P. (2021). "Unexpected larger distribution of Paleogene stem-rollers (Aves, Coracii): new evidence from the Eocene of Patagonia, Argentina". Scientific Reports. 11 (1): Article number 1363. doi:10.1038/s41598-020-80479-8. PMC 7809110. PMID 33446824.
  6. ↑ Báez & Pugener, 2003
  7. ↑ Aranciaga et al., 2019
  8. ↑ Jin et al., 2020
  9. ↑ Ramírez et al., 2016
  10. ↑ Jud et al., 2018
  11. ↑ Barrera et al., 2012
  12. ↑ Melendi et al., 2003

Bibliography

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