Abstract
Paleomagnetic evidence indicates that most of the extensive dike swarms cutting Triassic and older formations probably intruded in a time of regional tectonic and magmatic activity distinct from the late Triassic tectogenesis. The fossil magnetic directions of the dikes coincide neither with Late Triassic nor with Early Cretaceous paleomagnetic directions, which suggests a Jurassic age for the intrusions. The dikes were emplaced along tensional fractures that were the surficial expressions of deep-seated movements. The fan-shaped arrangement of these fractures indicates a southwestward decrease of the rotational component of the shear couple and a sinistral polarity of the shear movements. Periodic increases in tectonic and mafic magmatic activity, such as this one in the Jurassic, appear to be characteristic of Mesozoic deformations in the Appalachians.
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.
