THE ROLE OF DEEP CRUSTAL FAULTS ON DEFORMATION PATTERN IN EGHLID-DEH BID REGION AND SEISMOTECTONIC IMPLICATIONS FOR THE SANANDAJ-SIRJAN ZONE

Deep crustal faults have significant role on stress distribution and final deformation pattern of geological regions. In this paper, we investigate the role of Zagros suture a s an important tectonic element in the Iranian geology and strike-slip Deh Shir-Baft fault regarding their situation and geometry on stress distribution and displacement pattern in Deh Bid-Eghlid area as part of the Sanandaj-Sirjan Belt using Finite Element modeling. In this paper, the role of Zagros suture as an important tectonic element in the Iranian geology and strike-slip Deh Shir-Baft fault regarding their situation and geometry on stress distribution and displacement pattern in Deh Bid-Eghlid area in the most complicated structural zone of the country, the Sanandaj-Sirjan Belt is investigated using Finite Element modeling. Our results showed that position and selected dip for the suture have significant role on the stress and displacement fields and are both totally comparable with plate boundary shear zones demonstrating dextral transpression. The results show that position and selected dip for the suture have significant role on the stress and displacement fields and there is an anti-clockwise rotational deformation in the region and stress accumulation towards the faults convergence point. These results indicated a right lateral component along the Zagros Thrust Line changing from 4 mm/year in the north to 3 mm/year in the south are totally comparable with plate boundary shear zones demonstrating dextral transpression. This is fairly consistent with a suture zone located at or very close to the Zagros Thrust Line place. Regarding to the seismic gaps or instrumental data deficiency in the region, such a component will be important in evaluation of seismicity and risk analysis and also in prediction of future earthquakes. Based on our model, such a character could be due to stress accumulation in the region on the model, such a character could be due to stress accumulation in the region. Some recent field surveys including micro and macro-tectonic data as well as geomorphologic evidence support such a conclusion.