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.

Galeotti, S., Lanci, L., Florindo, F., Naish, T.R., Sagnotti, L., Sandroni, S., et al. (2012). Cyclochronology of the Eocene-Oligocene transition from the Cape Roberts Project-3 core, Victoria Land basin, Antarctica. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 335-336, 84-94 [10.1016/j.palaeo.2011.08.011].

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

Sandroni, Sonia;Talarico, Franco Maria
2012

Abstract

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.
Galeotti, S., Lanci, L., Florindo, F., Naish, T.R., Sagnotti, L., Sandroni, S., et al. (2012). Cyclochronology of the Eocene-Oligocene transition from the Cape Roberts Project-3 core, Victoria Land basin, Antarctica. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 335-336, 84-94 [10.1016/j.palaeo.2011.08.011].
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/8110
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