TRACING CALCITE PRECIPITATION WITH SPECIFIC CONDUCTANCE IN A HARD WATER ALPINE LAKE

Laboratoire de Ge´ochimie des Eaux, Universite´ Denis Diderot—Paris 7, Case postale7052, 2 place Jussieu, 75251, Paris, Cedex 05, France(First received 13 July 1999)Abstract—The authors discuss the reliability of a new method used to depict precisely the authigeniccalcite precipitation process in the water column of a mesotrophic alpine lake (Lake Bourget, Savoie,France). Complete chemical analysis of dissolved major elements shows that, in the epilimnion, calciumconcentration and alkalinity are the only chemical species presenting large variations. The behaviour ofthese two parameters is only related to calcite precipitation. The method is based on in situ specificconductance measurements (C