Multiproxy provenance analysis of Lower to Upper Cretaceous synorogenic deposits in the Southern Andes (34–35°S): Evidence of coeval volcanism during the onset of the Andean orogeny

The combination of detrital low-temperature thermochronology with previous U–Pb geochronology, petrological and sedimentological analyses, has proven to be a valuable approach constrain the provenance non-marine Lower Upper Cretaceous synorogenic deposits in northern Neuquén Basin. This work focuses on study Diamante Formation, fluvial succession that represents first products Andean foreland basin at 34–35°S. results indicate deposition Formation occurred simultaneously existence an active western volcanic arc during onset basin. facies associations evidence transition between backarc stages as well inception sedimentation foredeep. Petrographic together changes paleocurrents record limestone clasts suggest regional source shift. Apatite fission-track analyses (AFT) sample collected from lower part Albian central cooling age. also evidences remarkable presence angular apatite zircon crystals subordinated rounded subangular grains. Zircon (ZFT) upper yield two discrete populations ages, both reflecting source-cooling Late Jurassic (?161 Ma) Permian (?265 Ma). Finally, comparison AFT maximum depositional zircon-age reveals short lag time (ca. 3 ma), likely related rapid magmatic coeval ?110 Ma (Albian).