Dorotea Formation

The Dorotea Formation is a geological formation in the Río de Las Chinas Valley of the Magallanes Basin in Patagonian Chile whose strata date back to the Campanian to Maastrichtian of the Late Cretaceous.[1]

Dorotea Formation
Stratigraphic range: Late Campanian-Maastrichtian
~72–66 Ma
TypeGeological formation
UnderliesMan Aike Formation
OverliesTres Pasos Formation
Thickness100–350 m (330–1,150 ft)
Lithology
PrimarySandstone, claystone
OtherConglomerate
Location
Coordinates50.7°S 72.5°W / -50.7; -72.5
Approximate paleocoordinates52.9°S 60.5°W / -52.9; -60.5
RegionMagallanes Region
Country Chile
ExtentRío de Las Chinas Valley, Magallanes Basin
Type section
Named forSierra Dorotea
Named byKatz
Year defined1963
Dorotea Formation (Chile)

Description

The Dorotea Formation was first described by Katz in 1963. The formation comprises sandstones with frequent conglomerate lenses, concretionary levels and claystones. The Dorotea Formation includes calcareous sandstones with abundant marine invertebrate and fragmentary vertebrate fossils. Hervé et al. (2004) obtained a maximum radiometric age of 67.4 ± 1.5 Ma from detrital zircons contained in sandstones of the Dorotea Formation.[2]

The mudstones and sandstones of the formation were deposited in a fluvial environment. The formation conformably overlies the Tres Pasos Formation and is unconformably overlain by the Lutetian to Bartonian Man Aike Formation.[3] The thickness of the formation ranges from 100 metres (330 ft) in the Sierra Baguales in the north to 350 metres (1,150 ft) in the eponymous Sierra Dorotea in the south.[4]

Fossil content

The following fossils were reported from the formation:[5]

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See also

References
  1. Dorotea Formation at Fossilworks.org
  2. Otero et al., 2009
  3. Goin et al., 2020, p.9
  4. Otero et al., 2015, p.240
  5. Río de las Chinas Valley at Fossilworks.org
  6. Alarcón Muñoz et al., 2020
  7. Otero et al., 2015
  8. Goin et al., 2020
  9. Kuschel, 1959

Bibliography
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