Provenance of the Middle Jurassic-Cretaceous sedimentary rocks of the Arequipa Basin (South Peru) and implications for the geodynamic evolution of the Central Andes

The provenance of Middle Jurassic-Cretaceous sedimentary rocks deposited in the southern Peruvian Arequipa Basin has been investigated based on measurement 41 Sr-Sm-Nd isotopic compositions rocks, 993 U-Pb zircons ages, and 202 Lu-Hf zircon isotope data. Jurassic units are dominated by Brazilian/Pampean Grenville/Sunsas have juvenile to evolved Hf Permian zircons. These consistent with an Eastern Cordillera (EC) provenance. In contrast, Late Labra Formation presents first appearance Triassic-Jurassic increase Famatinian thus suggesting a mixed from EC and/or Altiplano Coastal (CC). Gramadal shows older which reflect major contribution Precambrian sources either Amazon craton or implying change Another is documented for Hualhuani located both CC EC. Finally, Santonian Chilcane characterized large Cretaceous indicating that it was mainly sourced CC. Our dataset associated depositional setting Early formations cumulative curves age distribution, indicate not back-arc but rather rift-like setting. Contrary formations, contributions retroarc foreland basin This statement further implies Andean eastward volcanic arc had directly rift control subduction these basins might be much younger than previously thought.