Analyzing Gravity and Magnetic Data for the Detection of Deep-Seated Faults and Faults within the Sedimentary Cover Near Habbanieyah and Razzaza Lakes in the Middle of Iraq

Abstract

This research deals with the processing and analyzing of magnetic and gravitational data for an area covering the region of Habbanieyah - Razzaza Lakes and its adjacent areas. The study includes data processing and mapping of the total gravity and magnetic anomalies for only the concerned region, then separating the residual anomalies by adopting the polynomial regression graphical method. The residual gravity anomaly reflects the variations of rock densities within the sedimentary cover. The horizontal gradient filter has been applied to the residual gravity anomaly in order to conduct the locations of fault planes within the sedimentary cover where sudden variations of gravity field take place. The quantitative interpretation for both gravity and magnetic anomalies yielded a preliminary determination for the depth to the center of major faults within the sedimentary cover. By constructing a gravity model along a profile which directed NE-SW and passing through the middle part of the study region, depth to the center of the effective faults found. This depth variation is due to the effect of tectonic activity which produced a set of faults, such faults caused the upward and downward structural motions and were responsible for positioning the deep high density causative slabs of bedrock. The residual magnetic field quantitative interpretation along two profiles crosses over anomalies at the NE and SW parts of the region yielded the depth to the top of magnetized basement rocks. The difference in depth of the basement rocks and the shifted anomaly locations reflects the effect of tectonic activity which may relate to a strike slip faulting in the higher depths.