The study of changes in deformation of Shahabad tapered zone (Northeast of Birjand)

Deformation in the east of Iran results from activities of fault zone with different trends. In the boundaries between these fault zones, a series of tapered zones has been created that various deformations are observed in it. The study of deformation changes in mentioned tapered zone is effective in recognition of genesis (the northern part of Sistan zone). The investigated area is one of the tapered zones which has been located between two right-lateral Koch fault (with northern-southern trend) and Shahabad (with northwestern-southeastern trend). In the boundary of this tapered zone, deformation has shown major changes from the location of convergence toward divergence. The amount of shortening of sedimentary folded tertiary units is around 13% percent in faults divergence and it increases to 69% percent toward the location of faults convergence.