The Byers Basin: Jurassic-Cretaceous tectonic and depositional evolution of the forearc deposits of the South Shetland Islands and its implications for the northern Antarctic Peninsula |
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Authors: | Joaquin Bastias Mauricio Calderón Lea Israel Francisco Hervé Richard Spikings Robert Pankhurst |
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Affiliation: | 1. Departamento de Geología, Universidad de Chile , Santiago, Chile;2. Earth Sciences Department, Université de Genève , Geneva, Switzerland j.bastias.silva@gmail.com https://orcid.org/0000-0001-6678-3173;4. Carrera de Geología, Universidad Andres Bello, Sazie 2119 , Santiago, Chile;5. Departamento de Geología, Universidad de Chile , Santiago, Chile;6. Earth Sciences Department, Université de Genève , Geneva, Switzerland;7. Visiting Research Associate, British Geological Survey , Keyworth Nottingham, UK |
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Abstract: | ABSTRACT This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U-Pb zircon ages are presented for the upper Anchorage Formation (153.1 ± 1.7 Ma) and the Cape Wallace granodiorite of Low Island (137.1 ± 1.7 Ma) as well as 40Ar/39Ar ages of 136–139 Ma for Low Island andesites. Data are also presented for a U-Pb age of 109.0 ± 1.4 Ma for the upper volcanic succession of Snow Island. In combination with published stratigraphy, these data provide a refined chrono- and litho-stratigraphic framework for the deposits herein referred to as the Byers Basin. Tentative correlation is explored with previously described deposits on Adelaide and Alexander islands, which could suggest further continuation of the Byers Basin towards the south. We also discuss possible correlation of the Byers Basin with the Larsen Basin, a sequence that shows the evolution of foreland to back-arc deposits more or less contemporaneously with the fore-arc to intra-arc evolution of the Byers Basin. |
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Keywords: | Tectono-stratigraphical evolution Weddell Sea South Shetland Islands Antarctic Peninsula Jurassic cretaceous basin evolution |
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