Paleomagnetic study on the volcanic rocks in Armutlu peninsula and Almacık mountain

Abstract

Twelve sites were sampled in the Armutlu Peninsula and Almaclk Mountain, in orderto gather paleomagnetic information about the tectonic evolution of the intrapontidesuture zone from the Eocene to the present. These sites are in the vicinity of the rightlateral strike slip North Anatolian Fault Zone.Thermal and alternating demagnetization methods were applied to the samples fromEocene igneous rocks, throughout the paleomagnetic analysis. Seven of the 12 sites gavereliable paleomagnetic results.The results obtained from each site on the Armutlu Peninsula were quite similar, thoughdifferent results were found from Almaclk Mountain. The mean declination angle of theEocene sampling sites is 14. 3° (clockwise), the mean inclination angle of the Earth'smagnetic field was found to be 52. 7° on the same samples in the Armutlu Peninsula.Today, the value of the geomagnetic inclination Angle is around 57 ° in this samplingregion. The difference in the inclination angle of the geomagnetic field between Eoceneand today shows that the region studied has migrated northwards. The paleomagneticresults are scattered in Almaclk Mountain and the declination angles were larger in thisregion (the site mean is between 175 ° and 185 0). However, calculated results show aclockwise rotation in this region. We may say that, the region studied has migratednorthwards when we compare the present inclination value of the Earth's magnetic field( 57 ° ) and the mean inclination of the sampling sites (54. 8 ° ).