MULTI ISOTOPIC AND GEOCHEMICAL CONSTRAINTS ON INTERCONNECTION AND HETEROGENEITIES OF WATER BODIES IN THE ADOUR–GARONNE DISTRICT (SW FRANCE) - THE CARISMEAU RESEARCH PROJECT IAEA–CN–151/145

摘要

The main objective of the Water Framework Directive (2000/60/EC) is to prevent further deterioration and protect and enhance the status of aquatic ecosystems in Europe. The success of the WFD will be mainly measured by the status of water bodies. Aims of the research project Carismeau are to provide further characterization of the groundwater bodies which have been identifi ed as being of primary importance and/or at risk in the Adour-Garonne district (1/5 of the French territory). For that purpose, combined geochemical analysis (major and trace elements), and isotopes (δ18O and δ2 H, δ34 SSO4 and δ18 OSO4 , strontium, boron, lithium, uranium and lead isotopes) are applied on one demonstrative water body named the Eocene sands aquifer. Preliminary results point out the extreme heterogeneity of water signatures between the selected water bodies but also within a single aquifer. The ongoing research will set out to demonstrate the role of lateral variation of facies and the interconnections between aquifers.