INTRACONTINENTAL MOVEMENTS IN WESTERN GONDWANALAND - A PALEOMAGNETIC TEST

Early Cretaceous intracontinental movements within Africa and/or South America, to account for misfit problem in the pre-drift reconstructio n of Western Gondwana, have been tested using palaeomagnetic poles fro m both continents. Each continent has been considered as comprising se parate subplates according to the boundaries proposed by Pindell and D ewey (1982) and Curie (1983): i.e., northern Africa (NAF), southern Af rica (SAF), northern South America (NSA) and southern South America (S SA). Visual and statistical distribution of Late Permian to Jurassic p oles from the African subplates indicate two distinct groups before ro tating SAF relative to NAF, while after the rotation they become indis tinguishable. The distribution and sparsity of data from South America limit the study in this continent as the data are statistically indis tinguishable before and after rotation of SSA with respect to NSA. Whe n the test is extended to the reconstruction of Western Gondwana, the tightest grouping of the poles occurs when an intracontinental movemen t is assumed within Africa. This suggests that the misfit between the two continents is probably due to intracontinental deformation within Africa and not in South America. If confirmed, this may have profound implications in the kinematics of the processes related to the opening of the South and Central Atlantic Oceans and also the origin of the W est African Rift System.