ABSTRACT
The lower parts of the system are in contact with a sulfide aquifer, fed by rising waters from buried evaporitic formations and by seeping meteoric water. The phreatic waters are cold and rich in Cl−, Na+, and SO42−, with a rather high H2S content (up to 18 mg l−1). The saline content varies throughout the year, being controlled by the mixing ratio between meteoric and sulfide waters: therefore higher values (about 2 g l−1) occur at the end of the summer.
