Petrology, lithofacies, and sedimentary environment of Upper Cretaceous Abu Roash “G” in the AESW Block, Abu Gharadig Basin, Western Desert, Egypt

• Published in: Journal of African earth sciences (1994) 2018-09, Vol.145, p.178-189
• Main Authors: Tian, Yu, He, Enjie, Chen, Hongde, Wang, Hehua, He, Wei, Yuan, Hao, Zhang, Yijiu, Liu, Shicheng
• Format: Article
• Language: English
• Subjects: Abu Gharadig Basin; Cretaceous sediments; Lithofacies; Mineral analysis; Petrology; Sedimentary environment
• ISSN: 1464-343X; 1879-1956
• DOI: 10.1016/j.jafrearsci.2018.05.017

The Cretaceous clastic rocks are main targets for petroleum exploration and development in the Abu Gharadig Basin. In this paper, the petrology, lithofacies, and sedimentary environment are studied based on the core samples, thin sections (TS), and scanning electron microscopy (SEM) data of Upper Cretaceous Abu Roash “G” (AR “G”) Member in the AESW Block, Abu Gharadig Basin, Western Desert, Egypt. Petrographic studies suggest that sandstones of the AR “G” are classified as sub-feldspathic arenites, quartz arenites, quartz wackes, and sub-feldspathic wackes. Based on rock textures and fabrics, eight lithofacies are identified within sandstones as gravelly sandstone (Sg), massive sandstone (Sm), cross bedded sandstone (Scb), laminated sandstone (Sl), laminated silty sandstone (Slz), ripple laminated sandstone (Srl), deformed laminated sandstone (Sdl), and bioturbated sandstone (Sb). Siltstone facies are classified as laminated siltstone (Zl), laminated sandy siltstone (Zls), laminated muddy siltstone (Zlm), lenticular siltstone (Zlt), and gravelly siltstone (Zg). Mudstone facies mainly consist of massive mudstone (Mm) and laminated mudstone (Ml). Petrographic study together with Lithofacies, typical sedimentary structures, palynomorphs, and biofacies suggest a tide-dominated coastal environment ranging from subtidal flat to intertidal flat in the study area. The tidal channels and tidal bars in the subtidal flat are the most favorable sedimentary microfacies for AR “G” sandstone reservoirs in the Abu Gharadig Basin, Western Desert, Egypt. •The Abu Roash “G” Member in the AESW Block consists of clastic sediments.•Petrology and mineral composition were analyzed for the sandstones.•Three categories and fifteen lithofacies were identified in the clastic sediments.•The clastic sediments were deposited under a tide-dominated coastal environment.