Effect of Alteration Zones on Water Quality: A Case Study from Biga Peninsula, Turkey

Widespread and intense zones of silicified, propylitic, and argillic alteration can be found in the Can volcanics of Biga Peninsula, northwest Turkey. Most of the springs in the study area surface out from the boundary between fractured aquifer (silicified zone) and impervious boundary (argillic zone). This study focuses on two such springs in KirazlA +/- area (KirazlA +/- and Balaban springs) with a distinct quality pattern. Accordingly, field parameters (temperature, pH, and electrical conductivity), major anion and cation (sodium, potassium, calcium, magnesium, chloride, bicarbonate, and sulfate), heavy metals (aluminum, arsenic, barium, chromium, cobalt, cupper, iron, lithium, manganese, nickel, lead, and zinc), and isotopes (oxygen-18, deuterium, and tritium) were determined in water samples taken from these springs during 2005 through 2007. The chemical analyses showed that aluminum concentrations were found to be two orders of magnitude greater in KirazlA +/- waters (mean value 13813.25 mu g/L). The levels of this element exceeded the maximum allowable limits given in national and international standards for drinking-water quality. In addition, Balaban and KirazlA +/- springs are > 55 years old according to their tritium levels; KirazlA +/- spring is older than Balaban spring. KirazlA +/- spring is also more enriched than Balaban spring based in oxygen-18 and deuterium values. Furthermore, KirazlA +/- spring water has been in contact with altered rocks longer than Balaban spring water, according to its relatively high chloride and electrical conductivity values.