Landscape and drainage evolution during the Cenozoic in the Salinas Grandes Basin, Andean Plateau of NW Argentina

AVILA PILAR; DAVILA FEDERICO; LÓPEZ STEINMETZ, ROMINA

GEOMORPHOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2020 vol. 353

0169-555X

The formation of endorheic basins is one of the main features, and likely the most distinctive, of the modern Andean plateau. These basins records thick Neogene-to-Modern evaporite successions that are considered to represent the onset of internal drainage and aridity. However, some isolated Paleogene evaporites have been described across the Argentine Puna, suggesting the beginning of the closed basin and the intermontane landscape prior to the main Miocene-Pliocene uplift. But evaporites beds are not conclusive evidence for such environments, given that their formation depends not only on the tectonically-driven paleo-drainage, but also on other sensitive variables as climate, and salinity of the sources. In this contribution, we discuss the paleo-drainage evolution across the eastern Puna plateau at 23°-24° S, combining landscape numerical modelling with outcrop and seismic stratigraphy. Our results suggest that endorheism would have dominated most (>80%) of the basin history, interrupted by a short (