GEOCHEMISTRY AND PETROGRAPHIC STUDIES OF GRANITES IN SERE, MAYO BELWA, NORTHEAST, NIGERIA

ABSTRACT This study investigates the geochemistry and petrography of granites in Sere, Mayo Belwa, located in the northeastern region of Nigeria. The area is part of the Adamawa Massif, a segment of the Precambrian crystalline basement, which underwent significant geological transformations through four major orogenic cycles: Liberian, Eburnean, Kibaran, and Pan-African. Eight samples collected in the study area were used for petrographic analyses in addition to the geological field mapping Technique; which were collected from local outcrops. The hand specimen descriptions and results of microscopic studies of the collected samples in the area revealed that quartz, feldspar and biotite are the predominant minerals in the rocks exposed, which are mainly granites. Fieldwork involved extensive geological mapping and sample collection, utilizing various tools including GPS, clinometers, and geological hammers. A total of eight granite samples were subjected to petrographic analysis under both PPL and XPL, to analyze the mineralogical composition. The mineral composition revealed that quartz is the dominant mineral, with biotite and feldspar with microcline also present, demonstrating typical characteristics such as pleochroism in biotite and multiple twinning in feldspar. Geochemical analysis highlighted variations in elemental concentrations, with samples exhibiting a high silica content, confirming their classification as felsic granites. Notable findings include the presence of significant aluminum oxide (Al2O3), sodium oxide (Na2O), and potassium oxide (K2O), indicating the dominance of feldspar minerals. The analysis also revealed that while sample SV1 is acidic and peralkaline, sample SV2 is acidic and subaluminous. Overall, this research contributes valuable insights into the geological composition of the granites in Mayo Belwa.