Seismic interpretation and cenozoic tectonic evolution of the Pozuelos Basin, Andean plateau, Argentina

ADAD, MARIA JOSE; LÓPEZ STEINMETZ, ROMINA; DAVILA, F.M.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2021 vol. 105

0895-9811

The Pozuelos Basin is today an internally-drained depositional area located at~22°22?S in the easternmost Andean plateau. Previous studies on sedimentarysystems across the region recognized three likely ways the Andean basins could haveformed: interconnected depozones within a simple eastward-migrating foreland orisolated depocenters in a broken foreland or intermontane basins within a risingplateau setting. In order to address the Cenozoic formation and evolution of thePozuelos Basin, and support some of these hypotheses, we conducted seismic datainterpretation, complemented with field surveys. Data allowed the correlation of theidentified seismic sequences (two basement and three Andean sequences), reflectorsand structures with the local geology. The eastern basin limit is defined by a thrustingzone, where the tectonic activity and the magnitude of deformation affected thesequences heterogeneously across strike the basin and time. Despite that in the UpperMiocene the basin configuration clearly was an isolated area within an intermontanesetting, seismic and stratigraphic evidences have divergent implications for the UpperOligocene - Middle Miocene stage, and here we discuss whether Pozuelos emergedas an isolated or interconnected sedimentary system. Some features like sequencesencroachments and stratigraphic characteristics in outcrops drove us to lean toisolated sedimentation scenarios within an intermontane configuration, likely a brokenforeland.