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Guichón Formation

Coordinates: 32°00′S 57°42′W / 32.0°S 57.7°W / -32.0; -57.7
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Guichón Formation
Stratigraphic range: Aptian-Santonian
~125–85 Ma
TypeGeological formation
Unit ofPaysandú Group
UnderliesMercedes Formation
OverliesArapey Formation
ThicknessUp to >100 m (330 ft) (in wells)
Lithology
PrimarySandstone
OtherConglomerate
Location
Coordinates32°00′S 57°42′W / 32.0°S 57.7°W / -32.0; -57.7
Approximate paleocoordinates38°24′S 30°00′W / 38.4°S 30.0°W / -38.4; -30.0
RegionPaysandú Department
Country Uruguay
ExtentNorte Basin
Type section
Named forGuichón
Guichón Formation is located in Uruguay
Guichón Formation
Guichón Formation (Uruguay)

The Guichón Formation is a Late Cretaceous geologic formation of the Paysandú Group in Uruguay. Dinosaur remains are among the fossils that have been recovered from the formation.[1]

Description

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The Guichón Formation comprises mainly pink-greyish to reddish sandstones, which contain moderate to well-sorted, subrounded, fine to medium-sized grains in a pelitic matrix. These sandstones (which compositionally are feldspathic wackes) are either massive or may instead exhibit parallel lamination, cross-lamination and graded bedding. These lithologies were deposited in southwest-trending alluvialfluvial systems comprising low-sinuosity channels traversing through sandy plains. Subordinate to the already mentioned sandstones are conglomeratic and pelitic lithologies, interpreted as channel-fill and overbank deposits, respectively. It is inferred that the Guichón Formation was deposited in warm, semi-arid climatic conditions.[2] The formation has been correlated to the Puerto Yeruá Formation of northwestern Argentina.[3]

The formation reaches a thickness of more than 100 metres (330 ft) in wells perforating the formation.[4] It is overlain by the Mercedes Formation and overlies the Arapey Formation.[5]

Fossil content

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The following fossils have been reported from the formation:[2][6]

Fossil eggs

See also

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References

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  1. ^ Weishampel et al., 2004, pp.517-607
  2. ^ a b Guichón at Fossilworks.org
  3. ^ Soto et al., 2009, p.13
  4. ^ Tofalo et al., 2011, p.616
  5. ^ Tofalo et al., 2011, p.617
  6. ^ Soto et al., 2009, p.19
  7. ^ Soto, M.; Carballido, J. L.; Langer, M. C.; Silva Junior, J. C. G.; Montenegro, F.; Perea, D. (2024). "Phylogenetic relationships of a new titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Uruguay". Cretaceous Research. 160. 105894. doi:10.1016/j.cretres.2024.105894.
  8. ^ Mones, 1972
  9. ^ a b Soto et al., 2011
  10. ^ Soto et al., 2012

Bibliography

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