Late Miocene - Quaternary forearc uplift in southern Peru: new insights from 10Be dates and rocky coastal sequences

We explore the coastal morphology along an uplifting 500 km-long segment of Central Andes, between cities Chala (Peru) and Arica (Chile). use accurate DEM field surveys to extract sequences uplifted shorelines study area. In addition, we consider continental pediment surfaces that limit both geographical vertical extent marine landforms. establish a chronology based on published dates for landforms surfaces. expand this corpus with new 10Be data shore platforms. The last 12 Ma are marked by three periods stability or subsidence dated ~12-11 Ma, ~8-7 ~5–2.5 ago. uplift accumulated these has been ~1000 m since 11 Ma; its rate can reach 0.25 mm/a (m/ka). For period only, during 800 ka, forearc accurately recorded carving numerous sequences. Within sequences, correlated terraces sea level highstands (interglacial stages sub-stages) up MIS 19 (790 ka), i.e., resolution ~100 ka. increases westward from 0.18 at Peru-Chile border ~0.25 in center It further northwestward, 0.45 mm/a, due influence Nazca Ridge. study, document unusual cyclic ~4 Ma-long cycles. This periodicity corresponds predictions made Menant et al. (2020) numerical models, could be related episodic tectonic underplating (subducting slab stripping) beneath