Calcite veins of the Stripa granite (Sweden) as records of the origin of the ground waters and their interactions with the granitic body

A Sr isotopic study combined with stable isotope determinations (δ18O and δ13C), petrographic observations and speciation calculations suggests that the Stripa granite (Sweden) contains at least three different types of calcite veins. One type with δ18O = -18 to -24 per-thousand (PDB) and 87Sr/86Sr = 0.7814 to 1.0696 probably formed at temperatures above 200 degree C, together with chlorite and epidote, during one or two metamorphic events which are recorded in the Rb-Sr systematics of some minerals of the granite at 1.4 and 0.8 Ga. Another type with δ18O = -12 to -18 per-thousand (PDB) and 87Sr/86Sr = 0.7406 to 0.7536 and mainly associated with chlorite, is most likely in equilibrium with the present day ground waters, which probably have reacted with the fracture minerals of the granitic body for a long time without any supply of external fluids. The third type of calcite with δ18C = -12 to -18 per-thousand (PDB), δ13C = -5 to -45 per-thousand (PDB) and 87Sr/86Sr = 0.7266 to 0.7406, could have formed from reactions involving methane oxidation or sulfate reduction in the presence of bacteria