ABSTRACT
Nowadays, the hydrogeological studies in the Catalan Potassic Basin (CPB), located 70 km NW of the city of Barcelona, focus on the characterisation of the Tertiary and Quaternary alluvial aquifers in order to define a conceptual model of their behaviour. The hydrogeochemical and isotopic data revealed a regional fresh water input in the shallow Tertiary and Quaternary alluvial aquifers coexisting with two main salinization sources: 1) a saline natural source related to the Eocene marine salt layers which produce a salinity increase with depth, mainly in the Tertiary formation, and 2) an anthropogenic saline point contamination related basically with mine dumps (usually associated with organic compounds). Furthermore, the conceptual model allows understanding the role of groundwater flow and geologic faults in some salt mine subsidence problems in the CPB.
