Abstract
The different upper- and lower-plate settings of detachment-related geometries of passive margins controlled by different extensional geometries can strongly influence the geodynamics and resultant vergence of subsequent active convergent margins during contractional orogenic development. The observed vergence along the Tasman Line and also the foreland-directed vergence of the early Tasmanides (Kanmantoo Fold Belt) and the miogeoclinal belt (Adelaide Fold Belt) support this concept. The less frequently recognized mixed vergence, like that in the Lachlan Fold Belt, has probably been caused by microcontinents and tectonically underplated terrane(s) which acted as structural backstops during the prolonged and complicated orogenic contraction. The geometry of the orogenic float (the mechanically separated surficial rock complexes and crustal units from the underlying continental and oceanic lithosphere) was strongly influenced by the relative displacement of several individual basement domains (some microcontinents) separated by long-lived, (i.e. reactivated), sutures and/or root zones.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
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.