9706735 Thomas One of the fundamental problems in early Paleozoic plate tectonic history of the Americas is where and how much the west coast of South America has interacted with the east coast of North America. One of the ways to test possible interactions of the continents is by testing lithostratigraphic correlations of Cambrian and Ordovician rocks. Thomas' study will do exactly that: compare and contrast the potential correlation of early Paleozoic sediments in the southeastern US with those of northwestern Argentina. The results will go a long way toward evaluating whether the correlations of these rocks permits a transfer in the Early Paleozoic of the Precordillera from Laurentia to Argentina .