Abstract
The polydeformed basement area in SE Norway is situated within the southwest border of the Baltic Shield. The investigated area covers the northern part of the Ostfold segment (the Ostfold Complex) and adjoining parts of the Median segment (the Romerike Complex). New Rb-Sr whole-rock age determinations are integrated with the structural evolution. The oldest rock unit is the Ostfold-St. Le-Marstrand formation. During successive stages the supracrustal unit was intruded by major granitic bodies now forming the biotite gneiss (oldest), the augen gneiss and metatonalite/granite complexes (youngest). The emplacement of the granitic units was separated by orogenic deformation events, F0-F3, recognized by the development of large-scale regional folding accompanied by amphibolite facies metamorphism. Rb-Sr whole-rock age determinations indicate a maximum age for the biotite gneiss (pre-F0) at 1.71 Ga; this age also marks the maximum age of the Gothian orogeny. Intrusion of the Nordstrand-Sormarka metatonalite/gr...
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.