Late Cretaceous/Paleogene Stratigraphy in the James Ross Basin

Abstract

AbstractLate Cretaceous sedimentary rocks are only exposed around the northern part of West Antarctica, on the South Shetland Islands and James Ross Island Group, Weddell Sea. They were deposited in very different tectonic settings and environments. The South Shetland Island sequence represents a Cenozoic outer-arc (Birkenmajer 1995) or fore-arc (Elliot 1988) succession composed mainly of terrestrial volcanic and sedimentary deposits. It should also be noted that some very thin and intermittent sequences of terrestrial sedimentary rocks interbedded within extensive volcanic units on King George Island, South Shetland Islands may be of Maastrichtian age. The Paleogene back-arc deposits comprise more than 1000 m of shallow marine to coastal fossiliferous clastic sedimentary rocks mainly of Paleocene and Eocene ages. They are exposed on Seymour and Cockburn islands approximately 100 km SE of the northern tip of the Antarctic Peninsula representing the uppermost part of the James Ross Basin succession.KeywordsJames Ross BasinLate CretaceousPaleogeneStratigraphyGustavMarambio and Seymour Island Groups