Hydrogeological Investigation of Karakaya and Ilicakoy (Ankara) Hotwaters

Abstract

In this study, the geological, hydrogeological, hydrochemical and isotope hydrology studies were conducted in an area of 236.2 km2 within Ayas (Ankara) county and vicinity. Within the framework of the study, geological, hydrogeological maps and geological and hydrogeological cross sections of 1/100 000 scaled were prepared. Geological and hydrogeological properties of the reservoir rock were determined; the relationship of hot waters and the cold waters, the recharge area and residence time of the waters were examined and a conceptual hydrothermal model of the studied area was proposed. In the hydrogeological studies, hydrogeological units in the studied area were identified. The Bilecik Limestone and the alluvium constitute the main permeable units in the studied area. Karakaya Complex is defined as impermeable, while the Hancili formation, Tekke volcanics and the Bozkir formation are stated as semipermeable. The evaluation of hydrochemical data indicates that both hot and cold waters existing in the studied area are type of Na-Mg-HCO3. Hot waters (200C -310C) are recharged from Bilecik limestone and Tekke volcanic rocks and conglomerate levels of the Hancili formation. Hot and cold waters were found to be supersaturated with respect to mineral species such as, calcite, dolomite and quartz. Environmental isotope data point out that hot waters have relatively long residence time which represents a deep groundwater circulation system in this studied area.