Tectonic effects of Abu-Jir Fault Zone on Euphrates and Fatha formations between Heet and Haditha western Iraq

Abstract

The current study comprised four outcrops: Heet, Sahliyah, Al-Baghdadi and Haditha, that comparison with, the Melh Tharthar-1well. We used a detailed field study to evaluate the tectonic effects of the Abu-Jir Fault Zone on the study area. We concluded through lithostratigraphic studies of the surface outcrops and the Correlation between them, that although the distances between sections are close, there is a substantial variance in lithofacies laterally and vertically. The layers of marly limestone in the Euphrates Formation are becoming thicker toward the southeast. It's a good indicator of a deeper environment than the northwest in the study area. The very quick subsidence of the eastern side of Abu-Jir Fault Zone during Late Early Miocene and Middle Miocene due to elastic isostasy of the Mesopotamian foredeep. The structural study reveals that the study area has been subjected to two types of stress during Miocene. The first one is extension in response to the tilt of the Mesopotamia sequence is took place as a result of the collision between Arabian and Eurasian plates during or after the end of the Early Miocene. The tilt created an extension zone along the axis of flexure, west of the Abu-Jir Fault System. The second type of stress is compression as a result of the strike-slip movement that occurred along the Abu-Jir Fault Zone during the Middle Miocene. The western block of the Abu-Jir Fault Zone moves northward relative to the eastern block, as a result of the right lateral strike-slip movement. The main forces come from the south during the Late Early Miocene and Middle Miocene, its source the Afar plume, as the upwelling mantle influence from the Afar plume reached the current study area during the Miocene (20 Ma), which is definitely the one that activates the western block of the Abu-Jir Fault Zone and pushes it towards the north relative to the eastern block.