TEXTURAL AND PETROGRAPHIC INTERPRETATION OF THE EBENEBE SANDSTONE OF IMO FORMATION IN ISIAGU, SOUTHEAST NIGERIA

The study investigates the textural and petrographic characteristics of the Ebenebe Sandstone, a sandstone member of the Paleocene Imo Formation exposed at Isiagu in southeastern Nigeria, with the aim of interpreting its depositional environment, provenance, and geological significance. The research builds on established sedimentological principles that emphasize the use of grain-size parameters, sedimentary structures, and mineralogical composition in reconstructing depositional processes and sediment transport history. Fieldwork involved detailed outcrop logging, identification of lithofacies, measurement of sedimentary structures, and systematic sampling. Laboratory procedures included sieve analysis for determining statistical parameters such as mean size, sorting, skewness, and kurtosis using the Folk and Ward (1957) method, alongside petrographic examination of thin sections to identify mineralogical constituents and diagenetic features. Results show that the sandstone ranges from fine to medium grain size, with sorting varying from well to moderately sorted, and textural maturity indicated by predominantly near-symmetrical skewness and leptokurtic distributions. Petrographic analysis reveals a quartz-rich composition (91–93% quartz) with minor feldspar and highly stable heavy minerals such as rutile, tourmaline, and garnet, classifying the sandstone as quartz arenite to subarkose. These features reflect a mature sediment derived mainly from high-grade metamorphic and granitoid source terrains of a cratonic or recycled orogenic setting. The integration of textural data, sedimentary structures such as cross-bedding, flaser bedding, and ripple marks, and petrographic signatures supports deposition in a moderate- to high-energy shoreface to tidal-influenced shallow marine environment. Overall, the study enhances understanding of early Paleocene sediment dispersal in the northern Niger Delta Basin and underscores the potential economic relevance of the sandstone as a groundwater reservoir and silica-rich industrial material.