Abnormal deflection in the some folded axes within Zagros fold and Thrust Belt, Northern Iraq, Mirawa-Mawaran synclinal axis as a case Study

摘要

The Mirawa-Mawaran synclinal structure was studied in order to establish the cause of the deflection in the fold axis from one segment to another. Field data obtained from two structural sections perpendicular to the major fold axis, one of the section located in the Mirawa segment, while the second section located in Mawaran part. This study indicates that the attitude of the fold axis within Mawaran segment is 300/03, with axial plane attitude 121/77, that indicate northeast vergence fold. In the Mirawa segment, the axis of the fold is 146/11, with axial plane attitude of 328/82 that refers to southwest vergency. The deflection of the fold axis is attributed to presence of major lineament in the middle junction of these two segments that coincide with a set of strike-slip, normal and reverse faults in this zone. The model of evolution for that syncline is discussed, and assumed to be related to bending of whole syncline at that junction part which coincide with that faults. This junction part may coincide with boundary of basement block that manifested on the surface as lineament or as different types of the faults.