Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

194 PATA Days 2024 and rockfalls associated with up to 100 m height scarps, etc. The current activity of these faults is corroborated by instrumentally detected seismic events within the last 30 years (e.g., Antayhua et al., 2002; Delgado et al., 2016; Gaidzik & Więsek, 2021; Taver et al., 2022; Woszczycka et al., 2024); however, predominantly without surface rupture (Benavente et al., 2015). To understand their seismic history and determine slip rates, recurrence interval, and potential seismic hazard, we opened five palaeoseismological trenches: four across the Trigal Fault and its branches (T1 to T4 in Figs. 1 & 2) and one across the Solarpampa Fault (S1 in Figs. 1 & 2). We also collected additional samples for further cosmogenic exposure dating from fallen blocks to test the coseismic nature of observed rockfalls and their relation with traced active faults. Fig. 1: Location of the studied paleoseismological trenches (S1, T1-T4; T4 according to Benavente et al., 2015) in the Colca Region on shaded relief map (30 m resolution digital elevation model, DEM from Shuttle Radar Topography Mission, SRTM (https:// earthexplorer.usgs.gov) . Active faults, according to Benavente et al., 2017. Initial findings from the trench excavations suggest a few seismic events in each trench, with a dozen to several dozen centimeters of surface rupture. However, we are awaiting the outcomes of Optically Stimulated Luminescence (OSL) and radiocarbon dating. Consequently, we cannot furnish the ages of reported seismic events or determine the recurrence interval or slip rates. Nevertheless, based on the observed displacements, we suggest that both structures, Trigal and Solarpampa Faults, are capable of producing earthquakes with magnitudes exceeding 7.