Serap Çolak (*), Mehmet Özkul (**) & Ercan Aksoy (*)
(*) Department of Geological Engineering, Engineering Faculty, Fırat University, 20070 Elazığ, Turkey. E-mail: eaksoy@firat.edu.tr
(**) Department of Geological Engineering, Engineering Faculty, Pamukkale University, 20070 Denizli, Turkey. E-mail: mozkul@pau.edu.tr