Geology and Mineral Deposits of Ondo State, Southwestern Nigeria: Assessment of Potential Benefits of Resource Exploitation

Abstract

Ondo State, situated in southwestern Nigeria within the Nigerian Basement Complex and the East Dahomey Basin, encompasses a diverse range of geologic units and mineral deposits. The state’s geology is characterized mainly by ancient Precambrian crystalline rocks, including grey gneisses, which are considered the oldest rocks in the Nigerian basement complex; granite gneisses of supposedly Liberian age (>2.5 Ga); pelitic gneisses, quartzites, schists (ancient metasediments); a 2nd generation of granite gneisses of Eburnean age (ca. 2.0 Ga), Proterozoic Schist Belts and Pan-African (ca. 600 Ma) granites and charnockite, overlain by Cretaceous to Recent sedimentary sequences. These rocks provide the framework for the formation of a variety of solid mineral deposits, including gold, limestone, glass sand, tar sand, bitumen, coal, kaolin, lateritic iron ore, dimension stones, and construction materials, as well as hydrocarbons in the onshore-offshore East Dahomey Basin. This paper reviews and presents a novel interpretation of the geological history and localization of mineral deposits in Ondo State, highlighting their economic potential and the benefits of exploiting these resources. Furthermore, the paper assesses the opportunities and challenges associated with sustainable resource utilization, including environmental degradation and community displacement. The findings demonstrate that responsible and sustainable development of these resources could significantly enhance the state’s economic landscape, stimulate industrial growth, bolster energy supply, promote job creation, advance infrastructure development, support community uplift, and generate substantial revenue for both the state and national economies. However, it is critical to consider environmental impacts, technological requirements, and practical policy frameworks to maximize the benefits. This paper contributes to a deeper understanding of the geology, age relationships, and mineral deposits of Ondo State, underscoring the necessity for further geological research and integrated resource management strategies that harmonize economic advancement with environmental conservation and community welfare.