Cyclochronology of the Eocene-Oligocene transition from the Cape Roberts Project-3 core, Victoria Land basin, Antarctica

• Published in: Palaeogeography, Palaeoclimatology, Palaeoecology
• Main Authors: Galeotti, Simone, Lanci, Luca, Florindo, Fabio, Naish, Tim R., Sagnotti, Leonardo, Sandroni, Sonia, Talarico, Franco Maria
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: Antarctica; CRP-3 drill hole; Cyclostratigraphy; Eocene-Oligocene climate transition; Antarctic; Cape Roberts; East Antarctic Ice Sheet; Ross Sea; The Antarctic; Victoria Land; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/11365/8110; https://doi.org/10.1016/j.palaeo.2011.08.011

About 34 million years ago, at the Eocene-Oligocene (E-O) transition, Earth's climate underwent a substantial change from relatively ice-free "green house" conditions to a glacial state marked by the establishment of a permanent ice sheet on Antarctica. Our understanding of the Antarctic cryospheric evolution across the E-O climate transition relies on indirect marine geochemical proxies and, hitherto, it has not been possible to reconcile the pattern of inferred ice-sheet growth from these "far-field" proxy records with direct physical evidence of ice sheet behaviour from the proximal Antarctic continental margin. Here we present a correlation of cyclical changes recorded in the CRP-3 drill hole sediment core from the western Ross Sea, that are related to oscillations in the volume of a growing East Antarctic Ice Sheet, with well dated lower latitude records of orbital forcing and climate change across the E-O transition. We evaluate the results in the light of the age model available for the CRP-3A succession. Our cyclostratigraphy developed on the basis of repetitive vertical facies changes and clast peak abundances within sequences matches the floating cyclochronology developed in deep-sea successions for major glacial events. The astrochronological calibration of the CRP-3 succession represents the first high-resolution correlation of direct physical evidence of orbitally controlled glaciation from the Antarctic margin to geochemical records of paleoclimate changes across the E-O climate transition.