Widespread Antarctic glaciation during the Late Eocene

• Published in: Earth and Planetary Science Letters
• Main Authors: Carter, Andrew, Riley, T., Hillenbrand, C.-D., Rittner, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2017
• Subjects: Earth and Planetary Sciences; Antarctic; Antarctic Peninsula; Dronning Maud Land; East Antarctica; South Orkney Islands; The Antarctic; Weddell; Weddell Sea; West Antarctica; Whitmore Mountains; Antarc*; Antarctica; Iceberg*
• Online Access: https://eprints.bbk.ac.uk/id/eprint/16774/; https://eprints.bbk.ac.uk/id/eprint/16774/1/Carter%2016.pdf; https://doi.org/10.1016/j.epsl.2016.10.045

Marine sedimentary rocks drilled on the southeastern margin of the South Orkney microcontinent in Antarctica (Ocean Drilling Program Leg 113 Site 696) were deposited between ∼36.5Ma to 33.6Ma, across the Eocene–Oligocene climate transition. The recovered rocks contain abundant grains exhibiting mechanical features diagnostic of iceberg-rafted debris. Sand provenance based on a multi-proxy approach that included petrographic analysis of over 275,000 grains, detrital zircon geochronology and apatite thermochronometry rule out local sources (Antarctic Peninsula or the South Orkney Islands) for the material. Instead the ice-transported grains show a clear provenance from the southern Weddell Sea region, extending from the Ellsworth–Whitmore Mountains of West Antarctica to the coastal region of Dronning Maud Land in East Antarctica. This study provides the first evidence for a continuity of widespread glacier calving along the coastline of the southern Weddell Sea embayment at least 2.5million yrs before the prominent oxygen isotope event at 34–33.5Ma that is considered to mark the onset of widespread glaciation of the Antarctic continent.