The thermal springs of Acquarossa and the nearby mineral springs of Soia
have outlet temperatures of 12 degrees to 25 degrees C, TDS of 2290 to
3000 mg/kg and Ca-SO4 to Ca-SO4-HCO3 composition. Chemical
geothermometers suggest reservoir temperatures close to 60 degrees C.
P-CO2 values at depth are estimated to range from 0.3 to 2 bar. delta D
and delta(18)O values indicate a meteoric origin and recharge elevations
of 1600 +/- 150 m above sea level (a.s.l.) for these thermal and mineral
waters. All these waters discharge from the overturned limb of the
Simano nappe, probably dose to the contact between basement and
underlying cover rocks. They therefore represent rain waters that
descend slowly, heat at depth and locally rise relatively quickly to the
surface, preserving part of their physical and chemical characteristics.
(C) 1999 CNR. Published by Elsevier Science Ltd. All rights reserved.