COMPARATIVE U/PB DETRITAL ZIRCON ANALYSIS OF SOUTHERN SOUTH AMERICA AND THE NORTHERN ANTARCTIC PENINSULA

The post-Jurassic tectonic evolution and paleogeographical connections of the previously contiguous Antarctic and South American regions remains poorly understood, but are essential for evaluating the timing and mechanism of separation which may have prompted the Oligocene glaciation of Antarctica with the formation of the Drake Passage. To evaluate separation history, a comparative detrital zircon analysis of sedimentary basins within each region should allow for recognition of similar and diverging provenance. In this contribution, we present results of U/Pb detrital zircon crystallization ages of Cretaceous-Oligocene sandstones from the Rocas Verdes and Magallanes Basins of Southern South America, as well as the Larsen Basin of the eastern Antarctic Peninsula. Strong similarities observed within provenance data metamorphic complexes of Trinity Peninsula Group of Antarctica and Duque de York of South America suggest a connection possibility until the Cretaceous. The Paleogene aged rocks of the Larsen Basin are dominated by zircons of Precambrian-Ordovician age, however this provenance data is unseen in the South American rocks. The zircons from similar aged rocks of the Magallanes Basin are largely derived from Jurassic-Cretaceous aged units associated with the formation of the Patagonian-Fuegian magmatic arc. By the middle Eocene the zircons populations in South America were largely contributed by Jurassic volcanics and metasedimentary Cordillera Darwin rocks. Data from the Larsen Basin suggests a divergence in provenance history prior to the late Paleocene with the onset of the Precambrian-Ordocivian aged zircons when compared to the Magallanes Basin. By studying the detrital zircon data of the sediment Antarctica and South America we will be able to aid in discovering accurate paleogeographical configurations and improve our understanding of the tectonic history and its potential effects on global climate change.