Geology and Petrography of Kanawa Member of Pindiga Formation Exposed at Ashaka Cement Quarry of the Upper Benue Trough, Northeasten Nigeria

The limestone facies of the Pindiga Formation in the Gongola Sub-basin represents a key sedimentary unit, extensively exposed at the Ashaka Cement Quarry. Limestone samples were collected and subjected to petrographic analysis. The thin sections were examined under plane and cross-polarized lights. Ten representative samples were analyzed to determine their mineral composition and optical properties. The results indicate that the limestone is dominated by calcite, dolomite, and iron oxide, with quartz and orthoclase as accessory minerals. Clay minerals, which constitute approximately 95% of the limestone, are not observable under a polarizing microscope. The presence of calcite and dolomite suggests potential for calcitization and dolomitization under favorable geochemical conditions. These findings highlight the industrial potential of the limestone for applications such as cement, fertilizer and glass production.