The James Ross Basin contains the only exposed sequence of Upper Cretaceous to Lower Tertiary marine strata in Antarctica. This sequence was deposited in an back-arc basin related to the development of the mid-Mesozoic to mid-Tertiary "Andean" active plate margin of the Antarctic Peninsula. Seymour Island has strata of Campanian to Oligocene age. These poorly consolidated sedimentary rocks contain a diverse invertebrate fauna that for the most part shows exceptional preservation. Plant microfossils are also common, and the vertebrate faunas include the first fossil marsupial from Antarctica. The Campanian to Paleocene sequence also spans the K/T boundary. This sequence provides the opportunity to investigate the tectonic evolution of the Antarctic Peninsula cordillera through study of the depositional settings of the strata, paleocurrent data, provenance of the detrital sediment, and petrology of the contemporaneous volcanic material. Results of these field and laboratory studies will be combined with information on the magmatic history of the cordillera to model the tectonic evolution of the source terrain which occupied the region of the northern Antarctic Peninsula.
