STRUCTURAL ANALYSIS OF THE BASEMENT COMPLEX ROCKS OF SOME PARTS OF IGARRA AND ITS ENVIRONS, EDO STATE: CONSTRAINED FROM FRACTURE ANALYSIS AND DEFORMATION

ABSTRACT

The study area, Ugbogbo and its environs is situated within the basement complex of the Igarra schist belt, a region that has experienced significant geological changes and have suffered a number of deformation over time. This deformation have left distinct structural features, which this study attempt to evaluate the deformation of the region by examining the fractures and conducting structural analysis. The techniques employed to achieve this is a combination of field survey techniques for data collection, fracture mapping to document fracture distribution and the use of advanced analytical tools such as rose diagram for visualizing fracture orientations and stereonet projections for detailed structural analysis. By analyzing the orientation and distribution of the structures contained in the rocks, the study involved plotting orientations on both rose diagram and stereonets to identify key structural trends. The analysis of these plots reveals a dominant NE-SW fracture trend that runs across the study area, which is a crucial finding. This indicates that the region was subjected to polyphase deformation, comprising of pre-Pan African and Pan African orogeny, the latter being associated with significant regional tectonic forces that shaped the current geological structure of the area. The NE-SW trend observed in the rocks is indicative of the earlier pre-Pan African orogeny, which predates the pan African events, highlighting the complex tectonic history of the region and the influence of multiple deformation phases over time.