Lithology, Structural Features and Geological History of the Area in and West of Al-Turbah Town, Southwestern Yemen

الملخص

The study area lays in and west of Al-Turbah town in the southwestern Yemen. This area has preserved a complex lithostratigraphy and structural history, which considered an important to the evolution of the geological events in southwestern of Yemen. It consists of dominantly varieties of rock unites including Precambrian basement (metamorphosed succession) such as gneisses, schists, amphibolites and migmatites. They in turn intruded by prominent exposures of granite, pegmatite, dolerite and basalts and unconformably covered by Mesozoic sediments comprising Jurassic Amran limestone and Cretaceous Tawilah sandstone and Tertiary volcanics. The area is affected by multiple ductile and brittle deformational phases structures. The ductile structures involve early stages of deformations affected only on Precambrian metamorphosed rocks including folding (F1-F3) and shearing contemporaneous with two events of metamorphism (M1 and M2). These ductile structures were followed by the formation of brittle structures were attended by voluminous mafic and felsic volcanic rocks encompassing the intrusion of mafic and felsic porphyry dykes. The large-scale faults during the Tertiary age are resulted by uplifting, creating the present-day distribution and configuration different rock units.