Geodynamics and its implications to environmental protection: A case study of Aule area, Akure, Ondo State, Southwestern Nigeria

Abstract

This research work evaluates the effects of geodynamics processes on the emerging local geology of an area, especially against the background of global tectonic activities, the gradual but continuous earth movement and the depletion of the ozone layer, as it were and its implications on the local geology of a place, especially as it affects the rate of weathering, fracturing and other geologic processes which may pose environmental challenges. A ten year template was adopted for this study, while geophysical and metrological approach was engaged in the study with the use of electrical resistivity method and rainfall data. Two techniques involving lateral resistivity profiling of near E-W orientation with a profile length of 150 m with electrode separation at a = 10 and 20 meters while electrode movement was at 5 meters. Nine vertical electrical soundings (VES) with maximum spread AB/2 = 100 m was carried out at same locations and period (July to August) as was obtained ten years ago for the purpose of effective correlation from the point of data acquisition, data analysis, interpretation, results and findings. Rain data within study area was also collected covering a period of ten (10) years was analysed and presented as bar chart. The result obtained revealed the nature of changes that has taken place within the study area in terms of weathering, and the rate of weathering in the last ten years. Vertical variation/changes occurred at a weathering rate of 1.573, 1.489 and 1.711 cm along the three traverses with average rate of 1.591 cm per year. Horizontal variations also indicated some changes in position of strata, implying an average yearly weathering of about 1.591 cm when compared with the principle of plate tectonics and gradual but continuous earth movement which is at the rate of about 2 cm per year. Therefore, the local geodynamic constant was determined from product of lateral movement and vertical earth weathering trend/gradient which is 3.182 cm2. The rainfall analysis reflects the global weathered changes which is a major contributory factor to geological processes/weathering.