Geochemical survey of the occurrence of trace metals in thermal groundwaters from Sicily, (Southern Italy)

摘要

The concentrations of 15 minor and trace elements were determined in 28 groundwater samples collected throughout Sicily. Thermal manifestations (T= 20-98°C) associated both with active volcanic areas (Etna, Pantelleria, Aeolian Islands) and with seismogenetic area (Belice area, Longi-Taormina fault zone) were selected for the present investigation. Trace metal concentrations range from a few tenths of μg/1 for ultra-trace elements (U, Y, Cs) up to 1-10 mg/1 for minor elements (Sr, Fe, Li, Rb). Due to the costal location of many sampling sites, seawater contribution is often important, at least for alkaline and earth-alkaline elements. However, the trace metal content is controlled by factors such as the master variables of the weathering solution (T, pH, Eh), the composition of the host rocks and the saturation state for primary and secondary mineral phases