The Sangemil Spa and the Dão fault system

Abstract

Thermal manifestation along the Dão fault system is expressed by thermal springs issuing at different temperatures, but with chemical composition remarkably similar for practically all major and many trace elements. Due to its temperature and special chemical components, these thermal waters have long ago been used for medical purposes. Sangemil Spa is the aim of this paper who presents a summary of geological and hydrochemical (including isotope measurements) studies carried out in the area. A model is proposed for the circulating water in the thermal spring.