Morphology and microstructure of migmatite rocks around Zaranda, Bauchi

Abstract

The study area covers Zaranda village and environs within latitudes 10°16'00"N  & 
10°13'00"N and longitudes 9°39'21"E  & 9°42'35"E. In the northern Precambrian base
ment, the area comprises mainly of pan-African migmatites, based on previous literatures. 
15 samples of rocks have been subjected to geochemical and petrology studies after car
rying out the geological mapping technique. The rock samples are found to contain high 
amounts of silicon oxides and low major oxides. The minerals identified are biotite, ilmen
ite, silimanite, garnet, quartz, and feldspar (plagioclase orthoclase). Microstructures were 
observed under cross- and plane-polarized light, indicating rock forms and resulting in 
partial melting of structures: melting of feldspar in quartz and vis-é-vis and cleavages in 
plagioclase feldspar. The paleosome appears finer and lighter as observed in the field. The 
remains of metasedimentary rocks as evident by quartzite rock are observed at a point 
within the study area. This work shows sodium-rich plagioclase and has successfully cat
egorized the homogeneous and inhomogeneous migmatite into metatexite, mesocratic, 
and leucocratic diatexites.