Subduction initiation in the Scotia Sea region and opening of the Drake Passage: When and why? ...

• Main Authors: van de Lagemaat, Suzanna H.A., Swart, Merel L.A., Vaes, Bram, Kosters, Martha E., Boschman, Lydian, Burton-Johnson, Alex, Bijl, Peter K., Spakman, Wim, van Hinsbergen, Douwe J.J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2021
• Subjects: Scotia Sea; Drake Passage; Kinematic reconstruction; GPLates; South Sandwich subduction initiation; Lithosphere delamination; Antarc*; Antarctic; Antarctica; Weddell Sea
• Online Access: https://dx.doi.org/10.3929/ethz-b-000472835; http://hdl.handle.net/20.500.11850/472835

During evolution of the South Sandwich subduction zone, which has consumed South American Plate oceanic lithosphere, somehow continental crust of both the South American and Antarctic plates have become incorporated into its upper plate. Continental fragments of both plates are currently separated by small oceanic basins in the upper plate above the South Sandwich subduction zone, in the Scotia Sea region, but how fragments of both continents became incorporated in the same upper plate remains enigmatic. Here we present an updated kinematic reconstruction of the Scotia Sea region using the latest published marine magnetic anomaly constraints, and place this in a South America-Africa-Antarctica plate circuit in which we take intracontinental deformation into account. We show that a change in marine magnetic anomaly orientation in the Weddell Sea requires that previously inferred initiation of subduction of South American oceanic crust of the northern Weddell Sea below the eastern margin of South Orkney ... : Earth-Science Reviews, 215 ...