1. ISM-CNR; P.O. Box 10, 00016 Monterotondo Staz. Roma Italy
2. Via dei Vascellari 34; 00153 Roma Italy
3. Department of Applied Geological Sciences and Geophysics; University of Leoben; A-8700 Austria
4. D.E.Ü Engineering Faculty; Geological Engineering Department; İzmir Turkey