Title : Water-rock interaction and hydrothermal equilibria in the Pertek (Tunceli, Turkey) geothermal system
Abstract:
The study area is located in Eastern Anatolia. The geology of the studied area is very important for the geodynamic evolution of the Eastern Taurus. Hydrogeological units were divided into the three units in accordance with lithological, structural and hydrogeological properties. First, the basement of the study area, marbles and dolomitic marbles within the Keban metamorphic rocks are highly fractured and karstified as main aquifer in particular thermal waters on the location. K?rkgecit and Karabakir formations occur as impermeable barrier rocks. Some parts of the limestone units act as aquifers of fresh waters. In addition, basalt and limestone of Karabakir formations having fractured also act as an aquifer for cold waters. Moreover, alluvium is the most important and favorable unit for cold groundwater production. There are most of thermal springs with low temperatures (35–37°C) with a discharge of 3 L/s in the geothermal system. The distribution of the geothermal potential appears to be controlled by the neotectonic features such that the highest potential is associated with the tensional tectonics in the Eastern Anatolia, being driven by the supply of heat from a deep-seated source and deep circulation of waters along the fracture zones.
The purpose of this study is to determine hydrochemical modelling of the Pertek geothermal system. Groundwater-rock and groundwater-clay/alteration mineral interaction processes are the predominant factors controlling the trace element hydrogeochemistry of thermal and cold waters. Low tritium values of thermal waters are indicated long groundwater circulation. Trace element composition of thermal waters occurs as the result of the groundwater-rock and groundwater-clay/alteration mineral interaction processes through long and deep circulation along the faults and fractures in the study area.
