Quaternary coastal uplift along the Coastal Cordillera along Central-South Chile: preliminary results from new marine terraces mapping

Our recent investigations along the Coastal Cordillera in Central-South Chile have identified up to three marine terrace levels in areas including Vegas del Itata, Purema, Coliumo, Punta de Parra, Talcahuano, and Coronel. These terraces appear to correlate with those previously mapped to the north between Pelluhue and Pichilemu, and to the south between Coronel and the Arauco Peninsula. Prior studies in the region have reported uplift rates ranging from 0.3 to 1.1 m/ka between Pelluhue and Pichilemu, and 1.8 ± 0.2 m/ka for the ~125-ka-old marine terrace on the Arauco Peninsula. Notably, areas with recognized faults exhibit higher uplift rates, while regions between these faults tend to have lower rates. The identified marine terrace levels have been associated with Marine Isotope Stages (MIS) 5, 7, and 9. Through a comprehensive analysis of the newly mapped terraces' shoreline angles, we anticipate deriving similar uplift rates for this area.