Geochemical study of thermal, mineral and groundwater in bursa city and surroundings

Bursa is a province full of ground waters, mineral waters and thermal waters since it is located in the juxtaposition of West Anatolian Extensional Zone and the southern branch of North Anatolian Fault Zone (NAFZ). Besides these different tectonic zones, Uludağ massive, which is highest mountain of Western Anatolia, is located in this region. Thermal waters discharge in the center of city at the north of Uludağ Pluton, the mineral waters reach the surface along Nilüfer creek in a tectonic valley at the south west of the pluton. Cold water springs have been discharged different altitudes from Uludağ to Bursa Plain. The stable isotope composition of hot springs are similar to cold waters suggesting that hot springs are fed from the altitudes of Uludağ (from 1800 m), heated as a result of geothermal gradient effects during circulation through the deeper levels of Bursa Valley and reach the surface through fault systems. No fast cycles or a distinct waterrock effect due to cold water composition is observed but a water-water effect can be seen. On the other hand a distinct water-rock interaction can be observed in mineral waters due to the interaction of water with granite and gneiss conglomerates. Mineral waters rise to the surface in a limited area are and the physical, chemical and isotopic compositions of these waters vary and the temperature of the waters increase as depth increases. The seasonal changes of the region?s meteoric waters due to the snow waters that melt from the crests of Uludağ and mix with ground waters, can be monitored from the physical and isotopic compositions. This also shows that the hot springs are strongly affected by surface effects. Keywords : Thermal Waters, Mineral Waters, Geochemistry