Shallow Thermal Anomalies and Their Role in the Breakup Evolution Along the Conjugate Margins of the Fram Strait (Svalbard and Eastern North Greenland), Indicated by Low‐Temperature Thermochronology

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Katrin Meier, Paul O’Sullivan, Malte M. Jochmann, Tino Wallrath, Patrick Monien, Karsten Piepjohn, Frank Lisker, Cornelia Spiegel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: apatite fission track analysis; (U‐Th‐Sm)/He thermochronology; Prins Karls Forland; De Geer Fracture Zone; North Greenland; Geophysics. Cosmic physics; QC801-809; Geology; QE1-996.5; Fram Strait; Greenland; North Atlantic; Svalbard
• Online Access: https://doi.org/10.1029/2023GC011074; https://doaj.org/article/b4a0ae0d2f504d2b98424c5743802ecd

Abstract We investigated highly mature sedimentary rocks exposed along both sides of the Fram Strait in the northern North Atlantic using apatite fission track and (U‐Th)/He thermochronology to obtain information on the thermal imprint of rifting and continental breakup processes along a sheared margin. Our data showed that the conjugate margins experienced several heating episodes, which we explain as resulting from heat transfer along segments of the De Geer Fracture Zone, a large continental transform system which connected magmatic centers north and south of the Fram Strait. Heating occurred prior to and during the Eurekan intraplate orogeny, which occupied the position of the present‐day Fram Strait during the Eocene. Heat transfer may have caused or contributed to lithospheric weak zones, which focussed deformation during intraplate orogeny. Movements along the transform fault system continued during the Oligocene, after the end of the Eurekan Orogeny, causing further structural weakening of pre‐existing fault zones. These were exploited during the final continental breakup leading to the opening of the Fram Strait. No unambiguous thermal signature associated with this latest stage of breakup was detected. Our data underline recent studies on the importance of structural inheritance and continental transform faults for the prolonged and complex processes of continental rifting and breakup.