The Skytrain plate and tectonic evolution of southwest Gondwana since Jurassic times

• Published in: Scientific Reports
• Main Authors: Eagles, Graeme, Eisermann, Hannes
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2020
• Subjects: Antarc*; Antarctica; Drake Passage; Scotia Sea; Weddell Sea
• Online Access: https://epic.awi.de/id/eprint/53297/; https://epic.awi.de/id/eprint/53297/1/Eagles_Eisermann_2020_SREP_Skytrain.pdf; https://hdl.handle.net/10013/epic.c454da5f-4cba-4d5e-9add-224b1dce0752

Uncertainty about the structure of the Falkland Plateau Basin has long hindered understanding of tectonic evolution in southwest Gondwana. New aeromagnetic data from the basin reveal Jurassic-onset seafloor spreading by motion of a single newly-recognized plate, Skytrain, which also governed continental extension in the Weddell Sea Embayment and possibly further afield in Antarctica. The Skytrain plate resolves a nearly century-old controversy by requiring a South American setting for the Falkland Islands in Gondwana. The Skytrain plate’s later motion provides a unifying context for post-Cambrian wide-angle paleomagnetic rotation, Cretaceous uplift, and post-Permian oblique collision in the Ellsworth Mountains of Antarctica. Further north, the Skytrain plate’s margins built a continuous conjugate ocean to the Weddell Sea in the Falkland Plateau Basin and central Scotia Sea. This ocean rules out venerable correlation-based interpretations for a Pacific margin location and subsequent long-distance translation of the South Georgia microcontinent as the Drake Passage gateway opened.