Study of dilution processes of sulfidic aquifer hosted by the Fiume-Vento karstic complex, Frasassi (Central Italy)

Sulfuric acid caves are widespread worldwide. In Central Italy, the Fiume-Vento karstic complex represents most important active hypogenic cave system hosting several interconnected lakes where groundwater moves towards sulfidic springs emerging along Sentino Stream. Stratification and dilution phenomena between freshwater water occur in many underground lakes, even if they remain still open these processes driven by stream-aquifer interaction or dripping water. The speleological knowledge coupled with geochemical surveys can help study circulation karst system’s inner outer portions. analyses on samples taken Stream, inside (dripping water) allow establishing origin of However, interactions cannot be excluded during flood events. Using tracer masse balance method (chloride sodium ions), discharge ranges 65 11 L/s. results presented this may understand other systems characterised sulfuric speleogenesis type.