Structural Pattern of Ghyrian Domes, Nafusa Uplift, Northwest Libya: Relation to Sirte Basin Rifting and Volcanic Activities

NE of the most favourable host rocks for REE metals in the Central Eastern Desert of Egypt is the Um Safi rhyolitic volcanics, which are thought to have a high potential source of REE metals associated with mostly thorium radioactive materials.Whereas, W. Ras Abda alkali feldspar high-K calc-alkaline perthitic granite is considered a high potential source for radioactive minerals in the Northern Eastern Desert of Egypt.The presence of REEs, Th, and U mineralizations in both rhyolitic volcanic rocks at Um Safi and at intrusive granitic rocks of W. Ras Abda areas are greatly controlled by internal tectonics that are related to the same extensional phase of deformation (WNW-ESE to E-W).The radioactivity in Um Safi area is higher than in W. Ras Abda but the W. Ras Abda area is richer in uranium minerals than Um Safi area.Uranophane, Uranothorite, and thorite are detected at Wadi Ras Abda area; while thorite is identified at Um Safi area.The resolved shear stress structural analysis indicates the direction of shear stress () on Um Safi rhyolitic volcanics as N-S direction, where it is slightly shifted to NNE-SSW and NE-SW at W. Ras Abda granitic mineralized fault zones.