Neogene to Quaternary tectono-geomorphic evolution and paleo-hydrology of the South Central Andes, NW Argentina

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The South Central Andes of Argentina are ideal to study the tectonic and climatic evolution of an actively growing subduction orogen. As an integral part of the Andes, sedimentary strata in intermontane basins straddling the margin of the intraorogenic Puna Plateau record valuable information on spatiotemporal characteristics of tectonism and climate of the eastward propagating orogen. Understanding the hydrologic and ecological changes caused by the uplift of orographic barriers is crucial for reconstructing such processes. We propose a multiproxy isotope study that entails the study of elevation changes, paleoclimate, and sedimentation characteristics, by utilizing stable isotope concentrations of oxygen (O) and hydrogen (H) from sediments in the intermontane basins and the foreland. This will be of paramount importance to understanding non-collisional mountain building and will improve our understanding of lateral orogenic plateau development and its influence on environmental parameters. We will gain insights into these complex issues by: a) obtaining modern stable isotope data from stream- and rainwater, soils, and plants; b) deciphering hydrologic and climatic changes through the H-isotope signature of lipid biomarkers extracted from the basin record; c) evaluating elevation changes and their effects on orographic precipitation using the isotopic signature of volcanic glass shards; and d) combining our results to understand the patterns of lateral orogenic growth during foreland segmentation and ensuing changes in the climate and depositional systems.