Structurally incorporated and water extractable chlorine in the Boettstein granite (N. Switzerland)

Samples from fresh to strongly hydrothermally altered granite have been analysed for water-, HNO₃-extractable and total chlorine. From the total of 115 ppm Cl, 60 ppm are contained in fluid inclusions, 1–2 ppm in apatite and 50 ppm in biotite. It is obvious that the high salinity (1,330 mg/l) of the deep ground water in this granite can be obtained by extraction from a fraction of chlorine originating from broken inclusions in tectonic breccias in fault zones.