The Main Lineament Trends of Central Iraq, Depending on the THD of Residual Gravity and Magnetic Maps Obtained from Four Upward Continuation Levels

Abstract

The upward continuation was used to obtain central Iraq's residual gravity and RTP magnetic maps at elevations 2, 12, 16, and 22 km. These maps are processed by the Total Horizontal Derivative (THD) technique to detect the main lineaments that represent the boundary of subsurface sources or faults. The obtained lineaments trends represented on the rose diagram and the main trends in the study area were found. The lineaments (faults) orders from the main trend descending, from gravity data, are N55W, N45W, N35W, N-S, and N65W, respectively, for the four considered upward elevations. The length of the faults obtained from gravity data ranges from 40-250km, while the length of faults obtained from magnetic data ranges from 20-100km. The lineament from the main trend descending, from magnetic data, are NS, N55W, N35W, N45W, N45E, N35E, N65W and N55E, respectively. The lineaments obtained from magnetic data indicate that the main trend in shallow sources is NW-SE, while for deep sources; the main trend is N-S. The NW-SE fault trends obtained from gravity data are related to the Najd faults system, while the N-S fault trends are related to the Nabitah system. Generally, it is indicated from the analysis of lineaments of gravity and magnetic data that the NW-SE is the main trend of shallow structures in most areas of central Iraq.