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

Metropolitan Region (Figure 1) and has a length of at least 50 kilometers and a depth of around 15 kilometers (Armijo et al., 2010; Vargas et al. 2014). Evidence suggests that the San Ramon Fault is responsible for major crustal earthquakes during the late Quaternary and that there is a possibility that new earthquakes have the potential to strongly impact the central depression where the city of Santiago is located (Armijo et al., 2010; Vargas et al., 2014; Riesner et al., 2017). M E T H O D S The study area is in the sector of San Carlos de Apoquindo, in Las Condes district, in the piedmont of the Andes Cordillera (Figure 2), where an eastern branch of the San Ramón Fault affects rocks and sediments (Figure 3). The main outcrop of this study is shown in (Figure 4), where stratified rocks are observed overthrusting unconsolidated Quaternary deposits. Another similar, but smaller outcrop is found at point 2, which was used as a reference to trace the previously proposed fault. A detailed description of the outcrop was carried out, meter by meter in the hanging wall, considering aspects such as clast and matrix sizes, clast shapes, and contact relationships. According to the literature, the damage zone is a volumetric zone around the fault core consisting of subsidiary structures such as joints, secondary faults, brecciation, produced by the activity (initiation, propagation, and termination) of faults (Jin-Hyuck et. al, 2016). These structures also typically serve as pathways for fluid circulation (Peacock, 2017). This report focuses on characterizing the structures around the fault core and accurately defining the damage zone of the fault in the area. Fig 1: Tectonic setting of the west Andean mountain front, and location of the city of Santiago (from Armijo et al., 2010).