THE AIRBORNE MAGNETIC SIGNATURE OF GÖKOVA GULF

Gökova gulf situated in the Aegian extension zone in Turkey has been considered very interesting for numerous research workers. Gökova gulf is located in the N-S regional extentional tectonic regime. N-S extension of western Anatolia initiated development of E-W extended grabens here. The bay extends 100 km E-W and 25 km N-S directions. Datça peninsula is in the south, Bodrum peninsula is located in the north of the Gökova gulf. In recent years ‘Full Tensor Gradiometer Potential Field’ methods (FTG) has found a practice area in between the gravimetric and magnetic methods. In the past as it was in the gravimetric methods vertical component of the magnetic field measurments used to be recorded. In recent years total field (x, y, z components) measurments have become more applicable. This method has been applied to the airborne magnetic field data. Total magnetic data components of the airborne survey have been calculated and FTG method has been used. Gökova gulf is seismicly very active. There is a magnetic anomaly recorded in the Gökova gulf. To be able to bring a new outlook to the geology of the bay, the magnetic anomaly has been analysed by using ‘Full Tensor Magnetic Gradiometer’ (FTG) method. At first Tx, Ty, Tz magnetic field components of the airborne anomaly have been calculated. To the calculated components Txx, Txy, Txz, Tyy, Tyz, Tzz derivatives have been applied to have an impression of the geological feature causing the anomaly. The anomaly in the bay indicated that ultramafic rocks, ophiolitic melange in the Datça peninsula continue under the sea to the Gökova gulf. Data indicate that northern boundary of the peridotites continues up to about 9 km to the northern coast of the bay. The method is considered to be useful to help mapping of the geological features with different magnetic sensitivities.