5 Analysis of Fault-Related Folding in South of Birjand

Mohammad Khalaj

doi:10.4236/ojg.2015.56037

Abstract

Folds have a significant development in the Cretaceous-Tertiary rock units of the northern part of Bagheran Mountains in southwest Birjand between Lut and Sistan structural zones. The general trends of fold axis and axial surface are E-W and the folds are less exposed by distance from mountain and plain boundary. Geometric and kinematic status investigation of folds (such as f2 fold in the middle part) and faults shows that faulting process has created some of the folds leading to their development. Such structures are described as fault-related folds. Also, analysis of geometry and mechanism of faults indicate that back thrusts have the largest influence on generation and development of folds in this region.

Highlights

The area of study is situated in westernmost end of Bagheran Mountain Range in southwest of Birjand City (40 km far from Khousf) between the following geographical coordinates: 59 ̊5'50"E - 59 ̊11'09"E and 32 ̊50'01"N 32 ̊50'35"N
Displacement along vertical component in easternwestern faulted zones has resulted in development of reverse faults in the subzone bounded by the Sistan and Lout zones
The investigations indicate that the relationship between folding and faulting in the region can be divided into two major categories

Summary

Introduction

The area of study is situated in westernmost end of Bagheran Mountain Range in southwest of Birjand City (40 km far from Khousf) between the following geographical coordinates: 59 ̊5'50"E - 59 ̊11'09"E and 32 ̊50'01"N 32 ̊50'35"N. As structural trends in Sistan zone in the northwestern part are orientated along E-W direction (Figure 1(a)), the main outcrop trend of rock units and faulted zones in the respective area is E-W. The respective three stages are crucial processes in regions with compressional deformations and in evolution of fold-and-thrust belts (Figure 1(b)) [1].

Results

Conclusion