Clast transport history influences Schmidt hammer rebound values |
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| Authors: | Telemak Olsen Josh Borella Timothy Stahl |
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| Institution: | 1. Frontiers Abroad, Christchurch, New Zealand;2. Frontiers Abroad, Christchurch, New Zealand
School of Earth and Environment, University of Canterbury, Christchurch, New Zealand;3. School of Earth and Environment, University of Canterbury, Christchurch, New Zealand |
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| Abstract: | The Schmidt hammer (SH) is widely used in geomorphology for relative- and calibrated-exposure age dating surfaces and deposits within landforms. This study employs a laboratory-based methodology to assess the effects of surface roughness, clast roundness, and clast volume on SH rebound values (R-values) by analyzing samples from three modern depositional environments (i.e. river, alluvial fan, talus). Each environment contains clasts of Torlesse supergroup greywacke sandstones with distinct roundness and micro-scale roughness characteristics. Roundness, surface roughness, and clast volume were all found to influence R-values significantly. The R-values from different deposit types are statistically significant and could potentially create an apparent age divergence of several thousand years for samples with the same exposure-age. © 2020 John Wiley & Sons, Ltd. |
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| Keywords: | Schmidt hammer exposure-age dating rock weathering surface roughness clast roundness New Zealand |
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