| Abstract |
In Turkey, the tectonic position of the eastern Mediterranean area between the Eurasian and African plates is controlled by the Anatolian and Aegean micro plates. The plate tectonic development results in the uplift of the Menderes Massif showing a dome shaped structure due to compressional tectonic features from Oligocene to Middle Miocene. From Early to Middle Miocene, the continental rift zones of the Büyük Menderes, the Küçük Menderes and the Gediz were formed by extensional tectonic features, which strike E-W generally and are represented by a great number of thermal waters, epithermal Hg, Sb, and Au mineralizations, and volcanic rocks of Middle Miocene to recent age. The thermal waters and epithermal mineralizations are related to faults, which strike preferentially NW-SE and NE-SW and are located diagonally to the general strike of the rift zones. These faults are probably generated by compressional tectonic stress, which leads to the deformation of uplift between two extensional rift zones. The thermal waters of Kýzýldere, Bayýndýr, and Salihli represent typical examples of active geothermal waters in the investigated area. The meteoric waters in the drainage area percolate at fault zones and permeable clastic sediments into the reaction zone of the roof area of a magma chamber situated in a probable depth of up to 5 km where meteoric fluids are heated by the cooling magmatic melt and ascend to the surface due to their lower density caused by convection cells. The volatile components of CO2, SO2, HCl, H2S, HB, HF, and He that are released out of the magma reach the geothermal water reservoir where equilibrium between altered rocks, gas components, and fluids occurs. Finally, the geothermal waters ascend along tectonic zones of weakness at the continental rift zones of the Menderes Massif, forming hot springs, gases, and steams. These fluids are characterized by high to medium CO2, H2S and NaCl contents. |