Abstract
Quantifying past changes in erosion rate is essential for deciphering earth surface processes and their driving mechanisms. Coupled in situ cosmogenic 14C-10Be has been shown to be a useful chronometer in detecting changes in erosion rate, but its detection ability is limited to rapidly eroding fluvial landscapes and changes greater than a factor of two; and in any case, it cannot uniquely quantify both the magnitude and the timing of change in erosion rate. Here, we establish a theoretical framework to show that this limitation can be overcome by combining the recently developed optically stimulated luminescence (OSL) rock surface exposure dating with the 14C-10Be chronometer. We demonstrate that the resulting OSL-14C-10Be composite geochronometer can determine both the magnitude and the timing of an abrupt change in bedrock erosion rate by a factor of < 0.8 or > 1.2 over 100–104 a timescales, where erosion rates are < 10−2 cm a−1.
Original language | English |
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Journal | Earth Surface Processes and Landforms |
Volume | 48 |
Pages (from-to) | 322–331 |
ISSN | 0197-9337 |
DOIs | |
Publication status | Published - 2023 |
Keywords
- Cosmogenic nuclides
- Erosion rate
- Exposure age
- Landscape evolution
- OSL surface exposure dating