Therapeutic characteristics of Galician mineral and thermal waters (NW-Spain) ascribed to their local/regional geological setting

Abstract

Galicia is located in the NW corner of the Iberian Peninsula (Spain). From a geological point of view, the territory belongs to the Hercynian chain and, more specifically, to a large outcrop dominated by igneous and metamorphic rocks called the Hesperian Massif or Iberian Massif. In some sectors the Hesperian Massif is partially covered by more recent sedimentary deposits. The geology of Galicia is very complex due to the age of the rocks that make up its substrate and their diversity. Thus, the hydrogeological behaviour of the underground medium (hydrodynamic and hydrogeochemical characteristics) will determine the therapeutic properties of the water emanating from the surface. In Galicia, aquifers are generally shallow with low mineralization, except for those whose waters come from deep fractured mediums. The chemical characteristics of the water are directly related to the geological matrix. The groundwater flows through the geological medium and is mineralogically enriched by heterogeneous chemical reactions. Galicia turns out to be an area rich in the potential exploitation, applications and use of different water resources. These resources are thermal, mineral-natural and mineral-medicinal waters. In this work, we have developed a study that relates the geology, hydrogeological and hydrogeochemical characteristics of the Galician substrate and their potential therapeutic indications. To achieve that, we have chosen to study the exploited waters with higher flow rates, including the natural mineral waters for human use.