Extremely low long-term erosion rates around the Gamburtsev Mountains in interior East Antarctica

Authors

  • S. E. Cox,

    1. Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Earth Institute at Columbia University, Palisades, New York, USA
    2. Now at Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.
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  • S. N. Thomson,

    1. Department of Geosciences, University of Arizona, Tucson, Arizona, USA
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  • P. W. Reiners,

    1. Department of Geosciences, University of Arizona, Tucson, Arizona, USA
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  • S. R. Hemming,

    1. Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Earth Institute at Columbia University, Palisades, New York, USA
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  • T. van de Flierdt

    1. Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Earth Institute at Columbia University, Palisades, New York, USA
    2. Now at Department of Earth Sciences and Engineering, Imperial College London, London, UK.
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Abstract

[1] The high elevation and rugged relief (>3 km) of the Gamburtsev Subglacial Mountains (GSM) have long been considered enigmatic. Orogenesis normally occurs near plate boundaries, not cratonic interiors, and large-scale tectonic activity last occurred in East Antarctica during the Pan-African (480–600 Ma). We sampled detrital apatite from Eocene sands in Prydz Bay at the terminus of the Lambert Graben, which drained a large pre-glacial basin including the northern Gamburtsev Mountains. Apatite fission-track and (U-Th)/He cooling ages constrain bedrock erosion rates throughout the catchment. We double-dated apatites to resolve individual cooling histories. Erosion was very slow, averaging 0.01–0.02 km/Myr for >250 Myr, supporting the preservation of high elevation in interior East Antarctica since at least the cessation of Permian rifting. Long-term topographic preservation lends credence to postulated high-elevation mountain ice caps in East Antarctica since at least the Cretaceous and to the idea that cold-based glaciation can preserve tectonically inactive topography.

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