Investigation of the sediment thickness of Büyük Menderes graben by geophysical methods

The Menderes Massif is a NE-SW trending crustal scale core complex which is located in Western Turkey. Massif forms the most important geological structure of Turkish-Alp orogenic zone and under the effect of North-South trending extensional tectonic since the Early-Miocene. Generally negative regional gravity anomalies are present in Western Anatolia. It is pointed out that regional negative gravity anomalies in continental stress field are created as a result of the common effect of a zone of low density and of thin oceanic crust. Büyük Menderes Graben has generally E-W trends (Darracott, 1972 and Condie, 1976) .Thus, large areas show negative Bouguer gravity anomaly observed at the west of Menderes massif is interpreted as a continuation of positive anomaly belt identified as a concave side of island arc (Rabinowitz and Ryan,1970, Özelçi, 1973). In this study the structural properties of the Büyük Menderes Graben is studied by using the Bouguer gravity anomalies. The maximum sedimentary thicknesses are calculated by using the boundary analysis method. By using the power spectrum method average sedimentary thicknesses are determined. To determine the boundaries and the trend of graben, the boundary analysis method applied to the Büyük Menderes Graben Gravity data and the boundary analysis method results and fault map which taken from preceding studies (Sözbilir, 2005) are compared. Keywords: Western Anatolia, Büyük Menderes, Gravity