STRUCTURAL FRAMEWORK BENEATH RIYADH REGION, SAUDI ARABIA USING GRAVITY AND AEROMAGNETIC DATA

Document Type : Original Article

Authors

1 * King Abdulaziz City for Science and Technology (KACST), P. O. Box 6086, Riyadh 11442, Saudi Arabia.

2 ** Department of Geology, Faculty of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.

Abstract

Gravity data for Riyadh region were acquired and processed to construct Bouguer, Free-air, Decompensative isostatic residual and Upward continuation anomaly maps. These maps have clarified the basement relief and its variation beneath Riyadh region. Four profiles extending east-west have been selected from the decompensative isostatic residual anomaly map to estimate the depth of basement rocks by applying the 2-D modeling technique. While Aeromagnetic anomaly and the total horizontal derivative anomaly maps were reduced to the pole (RTP) and used to identify the subsurface geological structures. It could be shown that the salt layer lies directly above the basement rocks with different thicknesses and areal distribution. It can be concluded that the structural framework beneath Riyadh region is complicated. The current study shows fault system with different directions, deeper extension were affected the basement complex and some geological formations attributed to certain geological period of tectonic activity. Some of these faults extend northeast-southwest, and separated Ar-Rayn province into its northern and southern parts, while other faults belong to the Najd fault system.