A Novel Approach for Reconstructing Slip Histories for Bedrock Fault Scarps Using Rock Surface Luminescence Dating

A newly developing method, optically stimulated luminescence (OSL)-depth profiles (DPs), provides a novel means of reconstructing and quantifying fault slip on timescales of 10(1-4) years. A targeted bedrock fault scarp along Langshan in north China, used as proof of concept, is divided into four sections based on four groups of OSL-DPs at different heights up the bedrock fault scarp. These have seismic displacements of 170, 80, 130, and 140 cm, and without considering the erosion rate, the exposure ages at the four displacements are 6-35 a, 19-84 a, 0.5-0.9 ka, and 2-5 ka, respectively. The ages are overall in chronological order, while the actual ages are likely underestimated due to erosion. After assuming erosion amounts according to the weathering characteristics, the calculated ages are mostly consistent with paleoseismic trenching studies. In addition, the method may identify a seismic event that previous studies did not identify.