Microfacies analysis of Middle Jurassic Tuwaiq Mountain Formation in Shaqra Quadrangle, Saudi Arabia

The Tuwaiq Mountain Limestone is a cliff-forming Middle Jurassic shallow-water shelf deposit in central Saudi Arabia. The Formation is responsible for the Tuwaiq Mountain Escarpment, a characteristic prominent cuesta that extends for more than 1200 km from south to north, with a maximum outcrop width of 20 kilometers in central Najd. It is overlain by marls and soft limestones of the Hanifa Formation and underlain by olive green shale of the Dhruma Formation. This study seeks to elucidate the microfacies of the carbonate successions of the Tuwaiq Mountain Formation in the Shaqra Quadrangle and develop a predictive conceptual depositional model using micropaleontological and depositional facies data of this carbonate succession to improve previous studies. The approach and methods to be followed in this project will combine field observations and laboratory analyses of the Tuwaiq Mountain Formation in the study area. The study will emphasize their sedimentology, stratigraphic facies, micropalaeontological and petrographic (microfacies) properties. The project includes lectures on carbonate microfacies by Dr. Axel Munnecke (consultant) for KFUPM students. The expected real, tangible and measurable outcomes of the project are: 1) Unraveling the depositional environments of the carbonate successions through field studies of Middle Jurassic Tuwaiq Mountain Formation of Saudi Arabia. 2) Increase international collaboration and mentoring opportunities for students pursuing a career in the field of carbonate microfacies analysis. 3) Develop a depositional successional history of the conspicuous stromatoporoid facies of the upper part of the Formation, to improve the understanding of their spatial distribution in subsurface hydrocarbon reservoirs. Carbonate microfacies analysis can provide important information to refine palaeoenvironmental interpretations. The proposed research will include thin section micropalaeontology of the field samples, with taxonomy, illustration and documentation of all biocomponents. This study will increase understanding and awareness of carbonate facies and their sedimentary significance in the Kingdom. It will contribute to future research in this field and assist understanding and evaluation of reservoir-associated carbonates in the subsurface. We envisage that the impacts of this research will have scientific, technical and economic significance for the Kingdom.