APPLICATION OF TILT ANGLE METHOD TO THE BOUGUER GRAVITY DATA OF WESTERN ANATOLIA

Abstract

In this study, tilt angle method was applied to Western Anatolia gravity data in order to estimate edges of the geological structures. Tilt angle was obtained in two different ways by using gravity and its vertical derivative. In potential fi eld methods, tilt angle technique is expressed as the ratio of vertical derivative to horizontal derivatives of anomaly. In the tilt angle map, 0° contours defi nes structure edges, half of the distance between ±45° defi nes depth of upper structure. In the fi eld work of the study, gravity data, which was measured in Western Anatolia, was used to obtain regional anomaly maps and tilt angle and tilt angle of vertical directional derivative were applied to these maps. A signifi ciant difference was observed between western and eastern parts of the N-S striking line, througout 28o longitude, from the results of tilt angle which was obtained by applying upward continuation method (50, 75 and 100 km) to the Bouguer anomaly. Same difference was determined from the results of vertical derivative of tilt angle which was obtained from upward contuniation of Bouguer anomaly. Depth values were obtained from the results of tilt angle and vertical derivative of tilt angle methods between 7 and 43 km in study area. The obtained results were compared with geological structural boundary and possible depths of geological discontinuities were estimated. In addition, obtained results were investigated with seismic activity in the study area and compared with previous geological and geophysical studies.