Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Separation of Paleostresses Phases Based on Heterogeneous Fault-Slip Data in the Central Part of Dehshir Fault

Document Type : Original Research Paper

Authors
M. R. Moshrefi far 1
A. Alavi 2
M. Mohajjel 3
1 Mining Engineering Department ,Yazd University,Yazd, Iran
2 Geology Department, Earth Science Faculty, Shahid Beheshty University, Tehran, Iran
3 Geology Department, Science Faculty, Tarbiat Modares University, Tehran, Iran
10.22071/gsj.2009.57540
Abstract
         In this research, separation of paleostress phases in the central part of Dehshir fault is investigated based on the study of heterogeneous fault-slip data and their related slickenside lineations. These data are measured from the Certaceous (Taft limestone), early Eocene (Kerman conglomerate) and Eocene (Volcanics) formations. The main criteria used here to identify sense of fault-slip are stratiographic separation, accretionary mineral steps, Riedel shears and tension gash. The existing faults in the region of investigated often show two NE and NW trend in which the latter is usually dominant. Based on the study of heterogeneous fault-slip data and their related slickenside lineations  and using the multiple inverse method, at least two phases are expected. These phases show that the axis of maximum principal stress, σ1, is at NE trend and that of minimum principal stress,σ3, is at NW trend. The location of σ3 usually indicates that the strike-slip and reverse strike-slip faults mostly occur in the region. In addition, the shape of the stress ellipsoid is prolate in the region.
Keywords
Strike-Slip fault
Dehshir Fault
Paleostress
Multiple inverse method
References
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Scientific Quarterly Journal of Geosciences
Volume 18, Issue 69
Winter 2008
Pages 64-73