Deep crustal architecture of the eastern limit of the West African Craton: Ougarta Range and Western Algerian Sahara

Abstract

Satellite gravimetric data is considered one of the most powerful and effective tool for regional geodynamic-structural zonation. The limit over the West African Craton to the Pan-African domain discussed in this paper has intricate geodynamic features that include collision tectonics, subduction and rift opening events, polyphased structural patterns made up of oceanic-continental reversed blocks of different ages, and a mosaic of several gravity and magnetic anomalies. This region is endowed with natural gas, coal and a variety of economic mineral deposits. In this study, a comprehensive analysis of the gravity data was used to construct models and maps to delineate localized deep suture zone and key proprieties of the lower crust within the Ougarta Range, Western Algerian Sahara. The results of density distribution constrained using several geological information was utilized to produce a new integrated tecto-geodynamic map of the Ougarta area. Analysis of transformed gravity maps and geological indicators show that the West African Craton and Pan-African domain converged obliquely with continuous eastward subduction. The observed layout of the suture zone in this study corresponds to the trajectory mapped since 2050 My. Guided evaluation of the resulting structural maps indicate the presence of positive and negative flower structures, typical of strike-slip movements along the eastern border of the West African Craton.