Geomorphological Changes in River Courses as an Indicator of the Presence of Hydrocarbonate Structures in Southern Iraq, Morphotectonic-Geophysical Study

In southern Iraq, many rivers have been subjected to changes, meander, and migration, in their courses, is changing temporally and spatially. The current study focused on analysing the causes of the meanders of many river courses and which they relate to the structural and oil fields in Basrah Governorate. Many sites were selected, the locations of the Tigris River (three sites) and Euphrates River north of Basrah, as well as the site of the Qarmat Ali river meander in the center of the city. In this study, the technique of Sub Bottom Profiler (SBP) is used to perform cross-sections and to identify the characteristics of river bottoms, and Transverse River Profiles (TRPs) index is applied to the cross-sections of the river bottoms for quantitative analysis to identify the main causes of these meanders. The results of the current study revealed that most of the changes and meanders of these rivers are influenced by neotectonics activity, therefore most of these meanders are associated with the presence of oil field structures. As the meander of Tigris river is affected by the Majnoon field structure and the meander of Euphrates river north of the city is affected by the Rumaila field structure (west of Qurna), the meander of the Qarmat Ali river influenced by Nahar Ben Umar field structure, so the application of this study has given active results about the meanders of these river courses which consider as an effective indicator of the presence of oil geological structures, so it can be applied in other locations.