The separation of South America from Africa during the Early Cretaceous isolated equivalent stratigraphic sequences on both continents. This is well established for rock sequences, including flood basalts, which were deposited prior to oceanic onset; however, earlier extensional events are also recorded by the resulting intracontinental basins. Of these, the depositional area containing the Late Permian-earliest Triassic Gai-As Lake is a prime example.