Abstract

A paleomagnetic pole and a new Ar-Ar date of 156.08 ± 0.05 Ma are reported for the Chon Aike Formation, an extensive plateau of ignimbrites, outcropping in the Deseado Massif (southern Patagonia, Argentina). The geographic coordinates and statistical parameters for the paleomagnetic pole, validated by a reversal test, are: Lat. = 84.3° S, Long. = 191.3° E, A95 = 8.6°, K = 13.3, N = 23. This pole shows a complete coherence with Late Jurassic and Early to mid-Cretaceous poles of South America, obtained exclusively from igneous rocks, avoiding any potential inclination shallowing. It is suggested that; a) southern Patagonia was an integral part of South America in the Late Jurassic; b) any reported vertical axis tectonic rotations must pre-date the Late Jurassic in this region; c) according to updated paleomagnetic data from igneous rocks, South America had very limited latitudinal drift between about 160 and 140 Ma; and, therefore, d) its apparent polar wander (APW) path, when compared with global apparent polar wander paths, does not support a large global shift or true polar wander (TPW) between 160 and 140 Ma.

Full Text
Paper version not known

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 call

Disclaimer: 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.