Isotope Hydrological Study on the Origin and Age of Deep Groundwater in the Semi-Arid Chaco Boreal, South America

摘要

An isotope hydrological study was carried out on deep groundwater in the northern and central semi-arid Chaco Boreal in Bolivia and northwestern Paraguay. This region is bordered by the Andes in the north and by the Pilcomayo River in the southwest. A satellite image shows a wide delta of palaeo-riverbeds, which consist of coarse sand and are covered with grass and open forest. The are heavy silty fluviatile sediments covered with dense, thorny vegetation between the palaeo-riverbeds.