Assuming that the trace metals found in fraction 2 originate solely from dissolution of dolomite, the only carbonate phase identified, one can calculate the following concentrations for these metals in CaMg(CO&: 190 and 300 ppm Cu, 65 and 70 ppm Ni, 150 and 350 ppm Pb, and 660 and 290 ppm Zn,
where the two values refer to Saint-Marcel and Pierreville sediments respectively.