Résumé
In karstic aquifers, organic carbon is a potential tracer of the fastflows coming from the soil. To study natural tracing using organic carbon,during karstic flows, we focused on the degradation of organic matter bybacterial activity during the infiltration of water. To demonstrate the impact ofTOC (total organic carbon) mineralization on the TDIC (total dissolvedinorganic carbon), we created a small-scale model of a karstic aquifer to studythe kinetics of degradation for dissolved and particulate organic carbon in twodifferent closed systems, one without carbonate and the other with limestone.During the three-month experiment we found that the proportion of C02produced by mineralization is significant. Therefore the production of C02resulting from the mineralization of organic matter must be considered in thecarbon balance of karstic aquifers.