Abstract
ON the basis of the positions of the magnetic south pole in the Triassic determined by palaeomagnetic studies of African and South American rocks, Creer1 has argued that the drifting apart of Africa and South America began in the Permian. Briefly, if South America and Africa are placed in such a position that their Palaeozoic polar wandering curves coincide, there is obtained a reconstruction very similar to that suggested by the shapes of the coastlines, and the earliest palaeopoles which do not coincide are those of the Triassic. In this argument, the Triassic palaeopole for South America was computed from a study of the lavas of the Serra Geral formation, in the southern part of Brazil. Unfortunately, a radiometric study2 of forty-one samples of basalt and dacite has shown that the principal phase of this igneous cycle is of Middle Cretaceous age, about 115–125 m.y.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
