Geochemical and structural segmentation inside the Laguna del Maule hydrothermal system

Abstract

The Laguna del Maule Volcanic Complex is one of the most studied active volcanic systems in the South American Andean range, but hardly any investigations have combined geochemical fluids with the structural arrangement. Therefore, we discuss the relationship between thermal waters and the structural characteristics in this volcanic system, in order to provide a new approach on the understanding of the hydrothermal system in the area. We carried out a geochemical analysis of thermal manifestations, focusing on Cajón Grande and Guanaco hot springs on the Argentine sector of this volcanic Complex, to compare our results with the ones already published in the literature on Chilean territory. The integration of the physicochemical analyses, isotopic compositions, and a morphostructural analysis allow us to identify a possible reservoir segmentation that we consider to be associated with a relative temporal evolution between these thermal manifestations. Here, we recognized a previous stage controlled by the volcanism of Cerro Campanario that influences Cajón Grande and Guanaco thermal emissions. Whereas, a current stage related to the actual active magmatism determines the composition of the other water manifestations. Therefore, our findings contribute to the understanding of the Laguna del Maule Hydrothermal System, and shed light on the role of structures associated with fluid circulation.