Tectonic elements and structural framework deduced from magnetic data of the Southern Desert, Iraq

The Iraq Southern Desert (SD) needs detailed studies to explore the subsurface, especially the deep and concealed basement. The aim of this work is to interpret the airborne magnetic survey data of the SD, which has a thick Phanerozoic sedimentary cover. The basement has not been imaged by deep seismic or even accessed by exploration wells. Magnetic edge-detection filters: total horizontal gradient, improved logistic, and second-vertical gradient (in the form of the signum transform) are utilized to help define the structural framework of the basement. The results of edge-detection filters are utilized in determining basement-dominated fault systems and aid in defining magnetic susceptibility boundaries. We have found a remarkable relationship between the interpreted fault systems and previously drilled hydrocarbon wells that could be used to indicate fault-bound structural traps. The results of edge filters also show linear clustering of magnetic structures that may indicate a distinctive phenomenon characterized old and reworked basement. The calculated magnetic susceptibilities utilizing two-dimensional forward modeling are consistent with metamorphic rocks and igneous intrusions. Further, two north–south-trending magnetic zones are displaced by a northeast-southwest-trending strike-slip movement. These zones are here considered as the northward projection of the Ediacaran Al Amar Suture in Iraq. We suggest a novel approach that combines edge-detection filters with a depth estimation method that can be successfully applied to discovering the stable (inner) parts of platforms with deep and concealed basements.