On the Isotopic Composition in δD and δ18O of Water and Ice During Freezing

Experiments on progressive unidirectional freezing are conducted to determine the evolution in δ D and δ 18 O of successive water samples and ice layers taken during the course of freezing. Results indicate that this evolution takes place, in a δ D– δ 18 O diagram, along a straight line with a characteristic slope. This slope, different from that due to the precipitation effect, gives a finger-print of the occurrence of a freezing or of a melting–refreezing process in the studied reservoir.