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

• Published in: Scientific Reports
• Main Authors: Eagles, Graeme, Eisermann, Hannes
• Other Authors: Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Projekt DEAL
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2020
• Subjects: Multidisciplinary; Drake Passage; Ellsworth Mountains; Falkland Plateau; Pacific; Scotia Sea; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1038/s41598-020-77070-6; http://www.nature.com/articles/s41598-020-77070-6.pdf; http://www.nature.com/articles/s41598-020-77070-6

Abstract 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.