GEOLOGY AND PETROGRAPHY OF THE MIGMATITES AROUND GUBI AND ENVIRONS, BAUCHI NORTHEASTERN NIGERIA

Geological mapping of Gubi and its environs a part of sheet 149, Bauchi, NE, was carried out and a geological map of the area was produced. The area is dominantly underlain by metatexite and diatexite migmatites, granites, and minor schist. However, this work is essentially centered on the migmatitic rocks. The samples of the migmatites and schist were analyzed in the field using a hand lens and in the laboratory using a petrographic microscope. The essential minerals identified are quartz, feldspars (albite, orthoclase, microcline, and andesine), biotite, clinopyroxene, some accessory minerals, and opaque minerals. The myrmekite microstructure was also identified. Although the rocks are all migmatites, they exhibited some variations in their color, structure, texture, and to some extent their mineral compositions, which is thus used in classifying the migmatites mor-phologically into metatexites and leucocratic, mesocratic, and melanocratic diatexites.