Sobral Formation

Sobral Formation
Stratigraphic range: Danian
~66–61.6 Ma
TypeGeological formation
Unit ofMarambio Group
UnderliesCross Valley & La Meseta Formations
OverliesLopez de Bertodano Formation
Thickness250 m (820 ft)
Lithology
PrimarySiltstone, mudstone
OtherConcretion, sandstone
Location
Coordinates64°18′S 56°42′W / 64.3°S 56.7°W / -64.3; -56.7
Approximate paleocoordinates63°12′S 66°36′W / 63.2°S 66.6°W / -63.2; -66.6
RegionSeymour Island, James Ross Island group
CountryAntarctica

Geologic map of Seymour Island, Antarctica with the Sobral Formation in brown

The Sobral Formation is a palaeontological formation located in Antarctica. It dates to the Danian stage of the Lower Paleocene period.[1]

Spectacular fossils documenting marine and terrestrial ecosystems soon after the (non-avian) dinosaurs became extinct at the Cretaceous-Paleogene boundary are found in this formation.[2] One of the most significant sites is on Seymour Island.

  1. ^ Bowman, V.; Ineson, J.; Riding, J.; Crame, J.; Francis, J.; Condon, D.; Whittle, R.; Ferraccioli, F. (2016). "The Paleocene of Antarctica: Dinoflagellate cyst biostratigraphy, chronostratigraphy and implications for the palaeo-Pacific margin of Gondwana". Gondwana Research. 38: 132–148. Bibcode:2016GondR..38..132B. doi:10.1016/j.gr.2015.10.018.
  2. ^ Crame, J.A.; Beu, A.G.; Ineson J.R.; Francis J.A.; Whittle R.J.; Bowman V.C. (2014). "The Early Origin of the Antarctic Marine Fauna and Its Evolutionary Implications". PLOS ONE. 7 (12): e114743. Bibcode:2014PLoSO...9k4743C. doi:10.1371/journal.pone.0114743. PMC 4262473. PMID 25493546.