Three-dimensional magnetic model of amphibolite complex

in Taskesti area, Mudurnu valley, North-West Turkey

A. Büyüksarac ^*+, S. Reiprich ^** and A. Ates ^*

^* Earthquake Research Department, Gen. Dir. of Disas. Aff., 06530 Ankara, Turkey

^** GeoForschungsZentrum, 14473 Potsdam, Germany

^* A.Ü., Fen Fak., Jeofizik Müh. Böl., Besevler, 06100 Ankara, Turkey

^*+ Corresponding author : E-mail : aydin@deprem.gov.tr

(Received 9 May 1998; accepted 16 July 1998 )

Abstract : The North Anatolian Fault Zone (NAFZ) crosses almost the whole northern part of Turkey. The active tectonism of NAFZ causes major earthquakes. Some big earthquakes originated from the NAFZ caused loss of lifes and properties. The movements of the fault create stress and strain in the surrounding area. Varying tectonic stress on blocks generates changes of the magnetization due to the magneto-elastic rock properties. In this paper, the previously modeled amphibolite complex that poduce the magnetic anomaly in Mudurnu valley, between Adapazari and Bolu, around Taskesti has been remodeled by an automatic three-dimensional modeling method. The new model suggests a magnetized body extending from near surface to the depth of 1.2 km having a susceptibility value of 22 x 10^-2(SI). The parameters of the new 3-D model improve the interpretation of tectonomagnetic signals.

Key Words: Amphibolite complex, Free air correction, Three-dimensional magnetic model.