Carbon Sources and Water-Rock Interactions in the Allier River, France

The Allier River is an important tributary of the Loire River, one of the major rivers in France. The Allier River presents both a natural environment upstream and a zone deeply impacted by mines and human activities. The δ13C and δ7Li combination show that the Allier River DIC is due to mixing of carbon from organic decay produced in a natural environment upstream, progressively enriched in DIC of anthropogenic origin downstream, and magmatic carbon inputs often associated with hydrothermal contributions.