Crystalline rocks form a major part of the basement complex of Nigeria, and Babanla area in Egbe-Isanlu schist belt is not an exception. These rock units are investigated for lithological characteristics and petrographic features that may be related to geodynamic setting of the area. Systematic geological mapping reveals the area is underlain by banded gneiss, granite gneiss, quartzite (quartz schist), marble, talcose rock (talc schist), epidiorite, coarse-grained granite and pegmatite. Field investigation also reveals the gneissic units are low-lying and Babanla area sits on Precambrian pegmatite occurring as dykes, veins and discordant bodies within the host gneissic rocks. The structural framework of Babanla area is dominated by discontinuities including faults, joints and fractures with widespread deformations characterized by mesmerizing folds and veining. Petrographic analysis of the crystalline rocks indicates the units contain varying amounts of common rock-forming minerals which include quartz, orthoclase, plagioclase, muscovite, biotite, hornblende and subordinate opaque minerals. The percentage mineralogical composition as revealed in thin section based on visual estimation and point counting indicates the rocks are mineralogically similar to those in other areas of the basement complex. These lithologies, which are mainly metamorphic and igneous are common and have predictable mineralogy but are unique in their respective localities as contributing to the understanding of the geodynamic evolution of the basement complex of south western Nigeria.
Keywords: Babanla, Egbe-Isanlu schist belt, lithological characteristics, petrographic, discontinuities, geodynamic evolution.
Citation: OlaOlorun, A. O. et al. (2025). Lithologic Relationship and Petrographic Features of Crystalline Rocks in Babanla Area, Egbe-Isanlu Schist Belt, Southwestern Nigeria. Adv Earth & Env Sci; 6(3):1-11. DOI : https://doi.org/10.47485/2766-2624.1070