Neotectonics of the Sarıköy-Đnova and Çan-Bayramiç-Ezine fault zones: basin formation, age and Slip Rates, NW Anatolia-Turkey

Abstract

he Sarıköy-Đnova and the Çan-Bayramiç-Ezine fault zones (SIFZ, ÇBEFZ) comprise the southern strand of the North Anatolian Fault System in the Biga Peninsula. They are located in the area between Sarıköy to northeast and the Dalyan settlement around Bozcaada in the North Aegean Sea to southwest. Both of the fault zones are active. This is evidenced by the 6 March 1737 (Ms =7.0) Đnova, 1st February 1809 Hurma (Ms = 6.1), and the 8 February 1826 Güllüce (Ms = 6.2) historical earthquakes resulted from these fault zones. Maximum lengths of fault segments comprising the SIFZ and the ÇBEFZ are 14 km and 15 km, respectively. Based on the maximum lengths of fault segments, the magnitude of the peak earthquakes to be originated from these faults are Mw = 6.3 and 6.6, respectively. Based on both the geological and geographic markers, the total right lateral offsets accumulated on the SIFZ and ÇBEFZ are 12 km and 20 km, respectively. These offset values imply to the slip rates of 4.6 mm/yr and 7.7 mm/yr, respectively. Five pull-apart basins were developed on both fault zones. These are the Sarıköy, Đnova, Kazabat, Çan and Ezine-Bayramiç basins. The first three of them are pure strike-slip pull-apart basins, while the type of the rest basins is superimposed. The angular unconformity between the nondeformed basin fill of Quaternary age and the folded to thrust-faulted basement rocks of pre-Quaternary age reveals strongly that the pull-apart basins have formed during the Quaternary time. This relationship also reveals that the commencement age of the strike-slip neotectonic regime and formation of associated fault zones are the Early Quaternary.