Lineament fabric, crustal structure and isostatic state of the Rub’ Al-Khali Basin from gravity data

Abstract

The Rub’ Al-Khali Basin is one of the largest hydrocarbon producing basins in the world. Since the basin is covered by the Quaternary sand sea, its structural configuration is known only from geophysical data. In this study, we determine the structural lineaments and Moho structure of the basin from high resolution gravity data of the WGM2012 model using recently proposed techniques. The spectrum analysis is used to separate anomalies due to sources at different depth levels from Bouguer gravity data. The edge detection techniques are applied to these anomalies to extract the structural lineaments. In addition, the gravity inversion has been used with the purpose to estimate the Moho depth of the area. The obtained results revealed that most of the trends of shallow lineaments are N-S, W-E and NW–SE directions, the major lineament trend of average depth sources is N–S, while the deep lineaments compare favorably with features of the Moho structure. Our gravity inversion shows a thick crust in the southwest part and thinner in the northeast region. The Moho result consistents with seismic studies in the area, while gravity lineaments add local detail to the framework of the East African Orogen, where the N-S trends in the basin are broadly collinear with the dominant East African orogenic trends. This study provides detailed subsurface structures for a better knowledge of the tectonic evolution of the area.