Coihaique Group

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Coihaique Group
Stratigraphic range: Late JurassicAptian
Chilesaurus holotype cast.jpg
Toqui Formation with Chilesaurus fossils
TypeGeologic group
Unit ofAysén Basin
Sub-unitsApeleg Formation
Katterfeld Formation
Toqui Formation
UnderliesDivisadero Group
OverliesIbáñez Formation
Lithology
PrimaryShale, volcaniclastic rocks, sandstone
OtherTurbidite
Location
RegionAysén Region, Patagonia
Country Chile

The Coihaique Group is a group of geological formations in northwestern Patagonia. From top to bottom the formations that make the group are Apeleg, Katterfeld and Toqui. The contact between the formations of the group are diachronous with Katterfeld Formation interfingering with the formations on top and below it. The lower and upper boundaries of the group are unconformities formed by erosion. The older parts of Coihaique Group represent a marine transgression while the younger parts evidences a return to non-marine conditions.[1]

Fossils in Toqui Formation[edit]

The rock formation preserves fossils from the Late Jurassic period of the Mesozoic Era.

Fossils of Chilesaurus (147 Ma) were found in the Aysén Region of Patagonia. It is an extinct genus of theropods in the family Tetanurae.[2] The fossil record also comprises a sauropod Titanosaur, a Camarasaur and a Diplodocid.

See also[edit]

References[edit]

  1. ^ Suárez, Manuel; de la Cruz, Rita (1994). Estratigrafía y paleogeografía mesozoica de Aisén nororiental (45-46 lat.s.), Chile (PDF). 7° Congreso Geológico Chileno (in Spanish). Concepción: Universidad de Concepción. pp. 538–542.
  2. ^ news.nationalgeographic.com National Geographic.com: "T. rex's Oddball Vegetarian Cousin Discovered", by Michael D. Lemonick, 2015-04-27.