Age and provenance of the Mio-Pleistocene sediments from the Sacaco area, Peruvian continental margin

Over the last decades, rocks from East Pisco Basin (EPB), on Central Peruvian coast (13°-16°S), have yielded an abundant and diverse collection of coastal-marine fossils, which are key for characterizing onset evolution modern Humboldt Current. Despite its paleontological richness, after almost 40 years study, spatio-temporal context deposits southern part EPB (Sacaco area) remains only broadly constrained, being mostly tailored to particular vertebrate-rich levels occurring throughout area. Here we build a composite stratigraphic section Sacaco area including three lithostratigraphic units (Pisco, Caracoles, Pongo formations), documents several discontinuities intraformational unconformities. We infer depositional ages based new radiometric (U–Pb), isotopic (Sr) biostratigraphic data, synthesize previous litho-, chemo-, bio-stratigraphic studies, present comprehensive chronostratigraphic review Mio-Pleistocene record sub-basin that allows us identify various local basinal events. Our results indicate that, in area, Formation ranges ∼9.6 4.5 Ma, overlying Caracoles 2.7 ∼1.9 accumulated up at least 1.4 Ma. These sedimentary successions continually subsiding setting show shallowing-upwards trend. Zircon U–Pb provenance analysis mainly Neoproterozoic, Cretaceous, populations, revealing discrete up-section changes source areas. Cretaceous sources continuously present, while older recycled-orogen vary through time presence abundance, indicating either paleogeographic or exhaustion.