Petrographic And Structural Characters Of The Basement Units In Kura Area Northeastern Nigeria.

Field mapping structural studies and petrography of the basement complex around Kura area in Bauchi State exposes variations in rock types and structural features. Deformation and migmatization of the rocks produced orientations in different directions with abundance of geologic structures such as foliation ptygmatic folds veins fractures and dykes. Most of these structures found on the rocks tend to trend towards the NE SW and E-W directions these trends are consistent with the general trends of Pan-African structures and of schist belt respectively. This study provides some dynamic information on the rocks exposed around the area and reveals the various rock types and their geological characteristics field relation macroscopic and microscopic features as well as structural elements. The main aim of this work is to study the geologic conditions of the study area in order to infer the level of deformation on the rocks with the intent of recognizing and further suggesting the variations in paleo-environmental regimes of pressure temperature and fluid activity. Results from the field shows that the area consists of migmatites granitic gneisses and biotite hornblende granites which all show a variety of colors textures and mineralogy. The displacement of distinctive mineralogy textures optical and structural characteristics led to the nomenclature of the rocks. Exposure of rocks in the area were mostly high and medium level outcrops with elevations ranging from 574m to 597m. Petrography reveals pelitic mineral assemblages suggesting high grade metamorphism. Characteristic structures such as gneissosity and typical metamorphic textures such as granoblastic textures are present in the migmatites and graniticgneisses respectively while granitic textures characterize the granites.