Hydrochemical investigation of Midyat Plane

ABSTRACT Master Thesis HYDROCHEMICAL INVESTIGATION OF THE MİDYAT PLANE Esra ÖZEL Fırat University Graduate School of Natural and Applied Sciences Department of Geological Engineering 2003, Page: 57 In this study Beyazsu and Karasu springs and the well waters in the Midyat Plane, was investigated. According to the meteorological data of Midyat meteorological station, the mean precipitation is 590,5 nun and the mean temperature is 15,7 °C for a period of 15 years. In the studied area evaporation-transpiration, excess water and deficit water were calculated and the climate was formulated according to Thornthwaite method. Regarding this formula the climate of the studied area is arid-slightly humid, nearly continental type, third degree mesothermal and has very much excess water in winter. Eocene Midyat Formation outcrops in the great part of the studied area. Upper Cretaceous- Paleocene Germav Formation composed of clayey limestone-sandstone-shale-marl, Lower Eocene Gercüş Formation composed of mudstone-sandstone-conglomerate, Eocene Midyat Formation composed of limestone and Quaternary Alluvium outcrop in the investigated area. The foldings have occured in the studied area that take place in the breastings of Southeast Anatolia, because of the movement of Arabian Plate. At the north of the studied area, thrusts and faults, associated with these thrusts are present. In the studied area the ground water bearing unit is Eocene karstic Midyat limestone. The origin of the anions and cations is described according to the chemical analysis of water samples. Using the chemical analysis data Schoeller, Piper, triangle, bar and circular diagrams were drawn, the relationship between the chemistry of waters and litology was investigated and the hydrochemical correlations were made. The major ions in the water samples are calcium, magnesium and bicarbonate. These ions must be originated from Midyat Formation. Ordering of the salts in the springs and the well waters, were calculated by means of the bar diagrams. According to tins, tiie dominant salts in the waters are Ca(HC03)2 and Mg(HC03)2, and minor salts in the waters are NaCl and MgS04. Drinking water diagram, USA Salinity Laboratory Diagram and Wilcox Diagram were drawn using the chemical analysis data. In this diagrams, the springs and the well waters were grouped in the "first class-good quality waters". Keywords : Midyat, Beyazsu Spring, Karasu Spring, hydrochemistry, karst. VI fcc ' ??«il hi in ii * u *n m fKUROLO