Interpretation of gravity anomalies to delineate some structural features of Biga and Gelibolu peninsulas, and their surroundings (north-west Turkey)

Abstract

On the basis of gravity data, derived anomaly traces were presented for the interpretation of some shallow structural features of Biga and Gelibolu peninsulas. Since building general understanding of subtle details about subsurface geology is of great importance considering that the study area is tectonically important, some advanced data processing techniques were implemented to gravity anomalies in a detailed manner. The procedures were performed using a MATLAB-based software package (Gravity and Magnetic Interpretation – GMINTERP). First, a finite element method was utilised to produce the residual data-set which is expected to reflect short wavelength anomalies arising from shallower geological structures, and thereafter some derivative-based algorithms were executed to analyse the residual data. The general anomaly patterns obtained from the applications clearly corresponded to the well-known surface geology map of the study area. Derivative-based anomaly maps put forward some findings about the existence of an old caldera structure in the western part of the Biga Peninsula. Additionally, abrupt lateral changes in anomaly amplitudes indicated the presence of some major structural discontinuities. Thus, findings yielded to make significant geological interpretations that might be important for further investigations. This study also showed that GMINTERP software package proved useful in assisting geological interpretation using geophysical potential field data-sets.

Keywords:

• gravity anomalies
• structural features
• data processing
• GMINTERP
• Biga and Gelibolu peninsulas

Acknowledgments

This paper is a part of PhD dissertation undertaken by the corresponding author (YLE) at Graduate School of Natural and Applied Sciences in Çanakkale Onsekiz Mart University, under the supervision of co-author (EY). Can Ertekin is warmly thanked for his great effort in digitising the 1/250,000 scaled surface geological map of the Biga Peninsula and its surrounding area. Thanks are due to Dr Abdullah Ateş, Dr Aydın Büyüksaraç, Dr Ömer Feyzi Gürer and Dr Mustafa Bozcu for their contributions. The location map in Figure 5 was generated by using Generic Mapping Tools (GMT) (Wessel & Smith, 1995) and Alper Demirci is thanked for his help in preparing this map. Two anonymous reviewers provided many helpful comments that clearly improved our paper.

Disclosure statement

No potential conflict of interest was reported by the authors.