Akademik Veri Yönetim Sistemi
Yerbilimleri/ Earth Sciences, cilt.34, sa.2, ss.83-100, 2013 (Scopus)
NW Iran, including the study area is one of the seismically active regions between Zagros Thrust Belt at the south and Caucasus at the north. In this region, an area known as Alborz-Azerbaijan zone includes many significant active fault zones. Not only large magnitude historical earthquakes (Ms>7), but also 1997 Ardebil (Mw 6.1) and 2012 Ahar-Varzagan (Mw 6.4) earthquakes reveal that the region is seismically active. The North Bozgush Fault Zone in this region has tens of kilometers in length and hundreds of meters in width. The zone has produced some large and destructive earthquakes. In this study five different study domains have been chosen along the North Bozgush Fault Zone. These are Sherbian, Danbaran, Anakiz, Damencan and Abgerm regions, respectively. The North Bozgush Fault Zone affects the Cenozoic units. Along this zone Eocene units thrusted over Miocene and/or Plio-Quaternary sedimentary units. The zone is mainly characterized by strike-slip faults with reverse component and reverse faults. Reverse faults striking N55°-85°E and dip of 40°-50° to the SW while strike-slip faults show right lateral slip with N50°-85°W and N60°-80°E directions. Our structural data analysis indicates that the North Bozgush Fault Zone shows σ1 principal stress (compression) with NW-SE direction and σ3 principal stress (extension) with NE-SW direction. The axis direction of σ2 principal stress is vertical and the stress ratio (R) is 0.12. These results suggest that the tectonic regime along the North Bozgush Fault Zone is transpressive. Fault slip analysis results are compatible with stress directions and GPS velocity results for NW Iran. Western part of the Bozgush Mountains is bounded with the Tabriz Fault Zone. Our field studies suggest that there is a genetic relationship between the North Bozgush Fault Zone and the Tabriz Fault Zone.