GEOLOGY AND PETROGRAPHIC STUDIES OF NGATUKPA, PART OF JEMA’A SHEET 188SE

The geological field mapping of Ngatukpa area of Jema’a sheet 188 SE located between longitudes 8º11ʹ50.22ʺE to 8°14ʹ27.4ʺE, and latitudes 9º11ʹ.00ʺN to 9º13ʹ32.43ʺN was carried out to delineate geology, petrography, structural characterization and petrogenesis of rocks. Field observation and petrographic studies that the area is underlain has mica schist, granite gneiss, rhyolite porphry and olivine rich basalt. Mica schist contains (20%) quartz, (25%) biotite, (40%) plagioclase, (5%) muscovite and (10%) opaque minerals. Granite gneiss contains (22%) quartz, (20%) biotite, (39%) microcline, (4%) muscovite and (5%) opaque minerals. Rhyolite Porphyry contains (23%) quartz, (45%) orthoclase, (12%) biotite and (20%) Ironoxide. Olivine-rich basalt contains (11%) olivine, (58%) sanidine, (8%) pyroxene, (20%) opaque minerals and 3% accessories minerals. The structural elements are evidenced that the study area has undergone polyphase deformation, anatectic melting and granitization process that led to the conversion of mica-schist to granitic gneiss during regional metamorphism.