Aeromagnetic data interpretation to locate buried faults in Riyadh Region, Saudi Arabia

Abstract

High resolution aeromagnetic data and various filtered maps are used in the present study to detect buried faults in the Riyadh region, Saudi Arabia. Filtering techniques such as Butterworth filter, tilt derivative, source edge detection (SED) and Euler deconvolution (ED) were used to map the structural lineaments in the study area. In this respect, the interpretation of the magnetic anomaly maps indicates that the area is dissected by a number of deep-seated faults that aligned mainly along NNW, NNE. The NW, NE, WNW and EW trending faults are present as second order. These faults divided the study area into three main zones of variable depth, width and pattern. To the northwest, there is an elongated high magnetic anomaly that indicates possible basement uplift, where a wide low magnetic anomaly dominates the western side of the area, with three local and circular low magnetic anomalies. This anomaly pattern is interpreted as a large and regional basinal area with three local depocenters seperated by structural uplifts. The southwestern corner of the area is characterized by a general shallow basement structure with local low magnetic anomalies that form the Awsat and Nisah grabens. The edges of the interpreted structural zones are delineated clearly using SED techniques and the average depth to the magnetic sources ranged from ~5300 m to ~ 1300 m. Key words: Aeromagnetic data, basement structures, faults, Riyadh region, Saudi Arabia.