Abstract
SUMMARY 122 oriented core samples were collected from folded Lower Cretaceous units at four localities in the Sierra Madre Oriental Mountains near Torreon, northeast Mexico. Palaeomagnetic analyses of these samples identify a stable synfolding remanence at three localities that was acquired during the Laramide Orogeny (Eocene). The fourth locality exhibited a post-folding or late-synfolding remanence. Each locality has undergone a regional rotation and at least three localities have undergone local rotations since remanence acquisition. By examining the relationships between the apparent polar wander paths for North America and Mexico, pole positions generated by this study and observed structural trends, it has been possible to evaluate the different contributions of local versus regional rotations and to calculate a least-locally-rotated Eocene pole position for the Torreon region. This pole (Lat. = 69.9N, Long. = 172.8E, n = 27, k = 30, ag5 = 5.2) agrees well with a published Mexican Eocene pole position for a locality located 450 km northnorthwest of the present study area. On the basis of this information, we conclude that a large fragment of northern Mexico has undergone a 10-15 post-Eocene counterclockwise rotation with respect to the rest of North America, in agreement with the model proposed by Urrutia-Fucugauchi (1981).
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.
