The Geology of Dumne Area in Southeastern Hawal Massif, Northeastern Nigeria

Dumne area, situated at the southeastern part of Hawal Massif, Northeastern Nigeria is underlain by gneisses, migmatites, Older Granites and Tertiary basalts with granite gneiss dominating. Both granites and gneisses contain mainly feldspars, hornblende, biotite, quartz and numerous opaque minerals and high silica (57.20 wt % and 60.50 wt %) and alumina (9.19 wt % and 7.40 wt %). Basalts have high concentration of Fe2O3 (11.08 wt %) contents, granites have high alkalis (Na + K) contents while the mean concentration of trace elements is generally low in all the rocks. The mineralogical and geochemical compositions of the gneisses and granites have strong similarity. The outcrops show gradational contact with each other but exhibit sharp contact with the surrounding sedimentary cover depicting igneous origin for the entire rock suite. The minerals exhibit strain and deformational features depicting a highly deformed rock suite.