This award supports cooperative research on the geophysics of Argentine and Antarctic margins to be conducted by John LaBrecque of the Lamont-Doherty Geological Observatory at Columbia University and Marta Ghidella of the Antarctic Institute in Buenos Aires, Argentina. This work will extend studies of the pre-Jurassic reconstructions of the conjugate margins of the Antarctic Weddell basin and the southern edge of South America. The procedure will be to compare magnetic and gravitational anomalies on both sides of the South Atlantic in Africa and South America to define the reconstruction of the prerift continent. Current information suggests that the Weddell and South American margins are conjugate rift margins but data is lacking for the Weddell side. This study will help provide such data through dipping seismic reflector measurements which can indicate thick accumulations of volcanically thickened oceanic crust. These will be correlated with high amplitude magnetic anomalies. The results will be shed further light on the theory of the breakup of the supercontinent Gondwana. In this study, the U.S. side will benefit from logistic support in Argentina, access to new data sets, and general advancement of geophysical science. They bring advanced scientific computing and improved instrumentation as additional benefits to the collaboration. The result will be an expanded data base for this sector of the southern oceans and encouragement for the U.S.-Argentine joint geophysical effort in Antarctic research.
