GEOLOGY AND PETROGRAPHIC STUDY OF THE BASEMENT COMPLEX ROCKS AROUND KOTORKOSHI AND ITS ENVIRONS, PART OF SHEET 54 S.E, ZAMFARA STATE, NORTHWESTERN NIGERIA.

ABSTRACT This study focuses on the geology and petrography of Basement Complex rocks in Kotorkoshi and its environs, located within Sheet 54 SE of the Nigerian Geological Survey. The region is predominantly underlain by porphyritic granite, granite gneiss, and migmatite, which exhibit diverse textural and mineralogical characteristics reflective of complex tectonothermal events. Field mapping and petrographic analysis were conducted to identify lithologies, structural features, and mineralogical compositions. Structural data indicate multiple deformation episodes, including jointing, veining, and minor faulting. Petrographic results revealed quartz, feldspar, biotite, and hornblende as primary minerals, with textures such as porphyritic and granoblastic suggesting both igneous and metamorphic origins. The geological structures show dominant NE–SW and NNE–SSW trends, consistent with the regional Pan-African tectonic framework. This research contributes to a better understanding of the local geology and supports future mineral exploration and geoscientific studies in the region.