Paleostress Reconstruction from Mesoscopic Fault Striae in Cretaceous Rocks in Piramagroon Anticline, NE Iraq
摘要
Paleostress reconstructed from fault-slip data in Piramagroon anticline in the high folded zone of Northeastern Iraq. The attitude of the fault planes, sense of the movement, and rake angle of the striations were collected from road cut outcrops and, veins in the fractures exposures of the Cretaceous rocks.The paleostress tensors attained from compressive and strike-slip faults relative to the horizontal maximum stress trend (σ1) are as follows (i) NNE‒SSW is the primary compressive tensor; (ii) NE‒SW, ENE‒WSW are primary compressive and strike-slip tensors; (iii) ESE‒WNW and SE‒NW secondary compressive tensor formed during relaxation episode. The NNE‒SSW and NE‒SW are extensional tensors relative to the horizontal minimum stress trend (σ3). They followed the primary stress episode. The SE‒NW extensional tensors represent the relaxed tensor derived from secondary compressive stress in the same direction. These various stress tensor directions may be attributed to the oblique collision between the Arabian and Eurasian tectonic plates.