Tectonic evolution of the eastern margin of the southern patagonian andes fold-thrust belt, from foredeep depocenter to uplift stages: u-pb detrital zircon geochronology and kinematic-structural modeling

Abstract

The beginning of the Austral-Magallanes foreland basin is recognized by the appearance of Punta Barrosa Formation sandy turbidites above Zapata Formation fine-grain deposits, this event marks the on-set of the compressional phase and hinterland uplift of the Southern Patagonian fold-thrust belt (Fig. 1). During foredeep deposition, the study region receives ~5000 m of marine sedimentation. Using detrital zircon U-Pb geochronology in ten sandstone samples, we calculate maximum depositional ages (MDA) of the units belonging to that stratigraphic sequence which began at 96.0 ± 1.5 Ma (first sandstones beds of Punta Barrosa Formation).