Cretaceous–Paleogene tectonic reconstructions of the South Scotia Ridge and implications for the initiation of subduction in the Scotia Sea ...

• Main Authors: Riley, Teal R., Burton-Johnson, Alex, Hogan, Kelly A., Carter, Andrew, Leat, Philip T.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Geological Society of London 2023
• Subjects: Geology; FOS Earth and related environmental sciences; Antarctic; Antarctic Peninsula; Drake Passage; Scotia Sea; South Scotia Ridge; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.6639909; https://geolsoc.figshare.com/collections/Cretaceous_Paleogene_tectonic_reconstructions_of_the_South_Scotia_Ridge_and_implications_for_the_initiation_of_subduction_in_the_Scotia_Sea/6639909

Abstract: The Cenozoic development of the Scotia Sea and opening of Drake Passage led to the dispersal of crustal blocks of the North and South Scotia ridges that today have a strong influence on the pathway of the Antarctic circumpolar current. The pre-translation positions of the crustal fragments of the Scotia ridges are uncertain, with correlations to both the Antarctic and South American plates. We present direct geochronology ( 40 Ar/ 39 Ar) from Bruce and Jane banks of the South Scotia Ridge that yield Late Cretaceous–Paleogene ages indicating a pre-translation magmatic history. Basaltic magmatism from Bruce Bank is calc-alkaline, akin to Cenozoic magmatism of the South Orkney microcontinent and the South Shetlands Islands, and in agreement with pre-translation tectonic models that place the crustal blocks of the South Scotia Ridge adjacent to the northern Antarctic Peninsula arc. The intra-oceanic arc magmatism at Jane Bank is Late Cretaceous in age (97.2  ± 1.1 Ma), and is not consistent with ...