Tectonic vs. climate controls on the evolution of a miocene intermontane basin, Patagonian Andean Foreland, Argentina

BUCHER, JOAQUÍN; MOYANO PAZ, DAMIÁN; LÓPEZ, MANUEL; D'ELIA, LEANDRO; BILMES, ANDRÉS; VARELA, AUGUSTO NICOLÁS; GARCÍA, MICAELA; FEO, RODRIGO; FUENTES, TOMÁS; FRANZESE, JUAN

INTERNATIONAL JOURNAL OF EARTH SCIENCES

SPRINGER

Año: 2021 p. 1 - 22

1437-3254

The interaction of tectonics and climate is considered the main determining factor on the development of different depositional systems (from aeolian to alluvial to lacustrine environments) in intermontane basins. The role of these external controls forces the paleoenvironmental evolution of intermontane basins. In this work we analyze a Miocene (15?11.5 Ma) synorogenic succession of an intermontane basin (Paso del Sapo Basin) of the Northpatagonian Andean foreland region. The evolution of the infill was synchronously developed with the Andean uplift and, consequently, with the rain shadow effect generation. A detailed sedimentological and stratigraphic analysis allowed to define eight facies associations, which are lateral and vertical stacked into three different depositional systems. Alluvial depositional systems occurred between 15?14.6 Ma, deltaic?lacustrine systems took place between 14.6?12.75 Ma, and a reinstatement of alluvial depositional systems occurred between 12.75?11.5 Ma. These variations in the type of depositional systems were contrasted with synchronous tectonic and climatic changes and some considerations about the role of these external controls were discussed in order to unravel their influence on the paleoenvironmental evolution. The onset of the deltaic?lacustrine depositional system was related to a tectonic reconfiguration whereas the reinstatement of the alluvial depositional system was associated with a regional aridization.