Identifying the geological structure of the Garyan area in northwest Libya using eigen-6c4 satellite gravity data

Abstract

Satellite gravity data can be used in this study to characterise hitherto unexplored regions and enhance scientific understanding of the studied area. However, the geological ambiguity of the study area makes it challenging to figure out the geological interpretation within and around the area. Therefore, this work focused on the Garyan area in the northwest part of Libya for the purpose of identifying geological structures. The Garyan region is a part of Jabal Nafusah (central Jabal) due to its geographic location and the character of the escarpment. The gravity data was analysed, designed, and developed into a geophysical model using the Oasis Montaj programme. Several analytic techniques are applied to gravity datasets for subsurface structure investigation, including (TDR) tilt derivative, (THG) total horizontal gradient, (PS) Power spectrum technique, (AS) Analytical signal, and (ED) Euler deconvolution. The results identified the presence of faults trending in different orientations (N-S, NW-SE, E-W, NNW-SSE, NE-SW), with source depths ranging between 300 and 2300 m, which indicates a complex tectonic history in the area. Clearly, this work will reduce the ambiguity of geological interpretations and provide better information on the dominant trends for future exploration activities in the study region. It also detects the contacts of density variation and estimates the depth of the gravity sources from satellite-EIGEN-6C4 gravity data.