Investigation of Subsurface Structures by Using Seismic Refraction Method, Northwestern of Al-Anbar Governorate / Iraq

Abstract

Seismic refraction survey is conducted along both banks of Euphrates River, northwestern of AL-Anbar governorate in order to investigate the subsurface structures at the study area. Four main layers are delineated from the results of interpretation to the seismic data. The first layer represents surface layer which corresponding to quaternary deposits , the ranges of velocity and thickness to the first layer are (600m/sec-950m/sec) and (2.26m-7.4m) respectively. The second layer corresponding to Euphrates Formation with ranges of velocity and thickness between (1400 m/sec -2000 m/sec) and (6.2 m-21.2 m) respectively. Third layer corresponding to Anah Formation with velocity and thickness ranges between (2400 m/sec - 3000 m/sec) and (20.6m-40.4m) respectively. Fourth layer corresponding to Baba Formation it has velocity range between (3333m/sec- 4000m/sec). The area at the right bank of Euphrates River is characterized by complex geological situation. Two faults are recognized on the right bank of Euphrates River (F1 and F2), both of them are normal. The first one is located at a distance of 230 m from the river bank and the second is located at a distance of 575m from the river bank. The area at the left bank of the Euphrates refer is characterized by horizontal layers and there is no evidence of any subsurface faults in this part of the study area