Sobral Formation

For the part of the Portuguese Lourinhã Formation, see Sobral Unit.

Sobral Formation
Stratigraphic range: Danian ~66–61.6  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Marambio Group
Underlies	Cross Valley & La Meseta Formations
Overlies	Lopez de Bertodano Formation
Thickness	250 m (820 ft)
Lithology
Primary	Siltstone, mudstone
Other	Concretion, sandstone
Location
Coordinates	64°18′S56°42′W / 64.3°S 56.7°W / -64.3; -56.7
Approximate paleocoordinates	63°12′S66°36′W / 63.2°S 66.6°W / -63.2; -66.6
Region	Seymour Island, James Ross Island group
Country	Antarctica
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.

See also

• Geology portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Antarctica
• List of fossil sites

References

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.

Further reading

• Baldoni M. A., Barreda V. D. (1986). "Estudio palinológico de las formaciones López de Bertodano y Sobral, Isla Vicecomodoro Marambio, Antártida". Boletín del IG-USP, Serie Científica. 17 (17): 89–98. doi: 10.11606/issn.2316-8986.v17i0p89-96 .
• Filkorn H. F. (1994). "Fossil scleractinian corals from James Ross Basin, Antarctica". Antarctic Research Series. 65: 1–96.
• Poole I., Mennega A. M. W., Cantrill D. J. (2003). "Valdivian ecosystems in the Late Cretaceous and Early Tertiary of Antarctica: further evidence from myrtaceous and eucryphiaceous fossil wood" (PDF). Review of Palaeobotany and Palynology. 124 (1–2): 9–27. Bibcode:2003RPaPa.124....9P. doi:10.1016/s0034-6667(02)00244-0. hdl:1874/31608. S2CID   129281012.