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

阿根廷中南部的安第斯山脉是研究俯冲造山带构造和气候演化的理想地区。作为安第斯山脉的重要组成部分，跨造山带内普纳高原边缘的山间盆地沉积地层记录了东延造山带构造和气候的时空特征。了解地形障碍物的隆起所造成的水文和生态变化是重建这些过程的关键。我们提出了一个多代理同位素研究，包括海拔变化，古气候和沉积特征的研究，通过利用稳定的氧（O）和氢（H）同位素浓度的沉积物在山间盆地和前陆。这将是至关重要的了解非碰撞造山作用，并将提高我们的了解横向造山高原的发展及其对环境参数的影响。我们将通过以下方式深入了解这些复杂的问题：a）从溪流和雨水、土壤和植物中获得现代稳定同位素数据; B）通过从盆地记录中提取的脂质生物标志物的H同位素特征来解读水文和气候变化; c）使用火山玻璃碎片的同位素特征来评估海拔变化及其对地形降水的影响; d）结合我们的研究结果来理解前陆分割期间侧向造山生长的模式以及随之而来的气候和沉积体系的变化。

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.