Abstract
The petrography of the basaltic rock in ugwukwu was studied in order to provide reliable information for their petrogenetic history. The petrographic results show that ugwukwu comprise of dolerite and basalt which intruded the oldest sediment in the area. The basaltic rocks (dolerites and basalts) occur as dyke. The mineral paragenesis of the dolerite is plagioclase+olivine+pyroxene+biotite with quartz as accessory mineral while the mineral paragenesis of the basalt is plagioclase+olivine+pyroxene+biotite+- quartz. The tectonism that occurred in the study area was accompanied by magmatism and this resulted to the emplacement of the igneous rocks. The mineral compositions in the rocks shows that the igneous suite in Ugwukwu are products of basaltic magma.