Contribution of gravity anomalies interpretation to the geology of the Jbel Saghro (eastern Anti-Atlas, Morocco): implications for the impact of structural control on sedimentation distribution

The objective of the gravity investigation in Saghro is to follow the depth of the causative sources and to examine the continuity of the geological formation boundaries. To achieve these objectives, the Bouguer anomaly data was subjected to a subtraction of the regional component and, then, interpreted in the light of three mathematical transformations. The upward-continuation enabled classifying the causative features to deep and shallow sources. Source-Parameter-Imaging allowed us to determine the depth and distribution of the basement uplifts, while the horizontal gradient was used to detect subsurface linear discontinuities, which correspond to geological lineaments. The horizontal gradient enabled revealing several faults trending mainly E-W, NE-SW, and NW-SE; these lineaments are linked to the Anti-Atlas tectonic events. The gravity analysis outcomes were validated by field investigations and interpreted in the light of the previous geological studies carried out in Saghro. The distribution of the basement uplifts is related to tectonics, which transformed the basement into high and low areas, and subsequently influenced posterior sediments distribution. The Saghro southern flank registers a thick and complete sedimentary sequence, whereas the sequence on its northern flank is thin, indicating relatively higher subsidence on the southern flank due to various faulting systems.