Dating Hanging-Wall Colluvial Breccia to Reconstruct the Long-term Normal Fault Evolution in Carbonate Terrains

Normal fault systems within extensional domains often create steep mountain fronts and associated colluvial breccia deposits. These deposits hold an archive of long-term fault activity and landscape evolution, yet they are rarely used to quantify fault slip histories due to their complex nature and dating challenges. In this study, we investigate the Zurim Escarpment in northern Israel, focusing on the Sajur Fault, to reconstruct the long-term morphotectonic history from syn-tectonic colluvial breccia units on the hanging-wall. We integrate U-Pb dating of calcite precipitates and luminescence dating of quartz grains within the breccia matrix to constrain the timing of two breccia depositional phases. Dating results constrain the age of the older breccia phase to ~2.5 Ma, and the younger phase to at least 1.2 Ma. The presence of colluvial breccia at ~2.5 Ma indicates that relief had already developed, constraining the minimum age of escarpment formation. Through clast provenance analysis, we link breccia deposition to the progressive exhumation of the fault footwall. This yielded a long-term slip rate of 0.14±0.02 to 0.15±0.02 mm/yr over the past 2.5 million years, lower than short-term rates derived from cosmogenic dating of fault scraps (0.2–0.5 mm/yr). This discrepancy reflects the temporal dependence of fault slip rates calculations, with values decreasing and stabilizing over longer timescales as they capture the full ratio of seismically active periods to intervening quiescent periods. Our results underscore the potential of syn-tectonic colluvial breccia as a long-term archive for fault activity and landscape evolution in carbonate terrains.