| Title | The Relation of Geothermal Resources with Young Tectonics in the Gediz Graben (West Anatolia, Turkey) and Their Hydrogeochemical Analyses |
|---|---|
| Authors | Yılmazer S., Pasvanoğlu S., Vural S. |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Gediz graben, young tectonic, geothermal, Turkey |
| Abstract | Paleozoic Menderes metamorphic rocks (gneiss, micaschist and marbles) comprise the basement in the area. The metamorphics are unconformably overlain by a Neogene sedimentary and volcanic rocks. The upper most part is represented by Quaternary alluvium. In Western Anatolia again E-W trending normal faults and NE-SW and NW-SE trending right lateral strike slip faults have been formed as a result of E-W trending compressions. Gediz Graben, like Büyük Menderes Graben, formed during Quaternary. That is why Quaternary volcanics formed along the E-W trending fractures, while the Neogene volcanic products of West Anatolia crop out near the N-S trending fractures and fissures. In the region, WNW-ESE trending faults have been formed during Upper Quaternary, while E-W and NE-SW trending faults formed during Lower Quaternary and this activity continues presently. In fact, geothermal resources are located at the intersect points of these differently-directed tectonic events. Gediz Graben is also a rift system and the formation of the Quaternary Kula volcanics of the region is related with this rift system. The heating source of the geothermal systems in Gediz Graben is these deepening young faults and Kula Volcanics. Many hot water resources occur along Gediz Graben starting from Alaşehir-Sarıgöl in the east. The measured reservoir temperature is 215oC in Alasehir, 155oC in Salihli, and 85oC in Urganlı geothermal system. Accordingly, temperatures in Gediz Graben decrease from east to west. The thermal waters of Alaşehir, Salihli and Urganlı geothermal systems are alkaline where carbonate alkalinity>non carbonate alkalinity. They are very soft waters which is rarely found in the nature. According to the classification nearly whole waters’ type is sodium-bicarbonated. |