Geology is the study of Earth, including its history, composition, processes, and life evolution. This discipline delves into Earth’s formation, its constituent materials, their structure, and the forces, both internal and external, shaping them, including phenomena like landslides, earthquakes, floods, and volcanic eruptions.
Earth materials, vital to human existence, include water, metals, and oil, extracted from deep within the planet. Geologists play a pivotal role in locating rocks containing valuable metals through exploration and devising methods for their extraction from host rocks through exploitation.
Understanding Earth’s history is foundational in geology, with the principle of Uniformitarianism highlighting the importance of present processes in understanding past and future events. For instance, geologists analyze past climates to comprehend current concerns like climate change.
They used tools such as the Geological Time Scale, established through relative stratigraphic relationships or absolute radiometric dating, to chronicle Earth’s geological events. Radiometric dating suggests Earth is approximately 4.54 billion years old.
Mineral resources, naturally occurring crystalline, inorganic substances with specific chemical compositions and structures, are accumulations of materials found on or within Earth that can be profitably extracted.
Mineral resources are categorized into three primary groups
- Energy minerals, which includes:
a) Nuclear fuels, such as uranium and zirconium.
b) Fossil fuels, including oil and coal.
- Metallic mineral resources, which consist of:
Ferrous metals like iron and iron-associated minerals.
Non-ferrous metals, including light metals such as lithium and bismuth, precious metals like platinum group metals, gold, silver, and tin, as well as base metals like copper, zinc, lead, nickel, chromium, arsenic, and cadmium.
- Industrial minerals, which involve:
Construction materials like stone aggregates, limestone, and clay.
Non-construction materials like chemicals, fertilizers, and ceramics.
Geology of Nigeria
Nigeria’s geological landscape is situated approximately between latitudes 4°N and 15°N and longitudes 3°E and 14°E, within the Pan African mobile belt nestled between the West African and Congo cratons.
The geological composition of Nigeria is chiefly characterized by three primary rock types: crystalline rocks (comprising igneous and metamorphic formations) and sedimentary rocks, each occurring in roughly equal proportions. The crystalline igneous and metamorphic rocks form the Precambrian-Palaeozoic basement complex, predominantly found in the eastern region of the country and extending through the north-central to the northeastern parts of Nigeria.
The sedimentary basins, on the other hand, consist of seven inland basins, including the Niger Delta, the Anambra Basin, the Benue Trough, the Chad Basin, the Sokoto Basin, the Bida-Nupe Basin, and the Dahomey Basin, all filled with sediments ranging in age from the Cretaceous period to recent times.
Mineral Resources of Nigeria
Mineral resources are commonly associated with specific geological epochs or metallogenic provinces. In Nigeria, three significant economic metallogenic provinces or epochs are identifiable, listed in decreasing order of age:
- Tin-tantalum (with traces of niobium) pegmatites, likely of Pan-African origin, situated along an east-west trending zone.
- Tin-niobium (with traces of tantalum and tungsten) greisens and granites, originating from the Mesozoic Younger granites found on the Jos Plateau.
- Lead-zinc sulphide veins found within Lower to Middle Cretaceous sediments of the Benue trough.
Principal Tectonic Environments
During the Archaean period, two primary tectonic environments can be discerned:
- High-grade zones: These regions host mineral deposits such as Ni-Cu in amphibolites (e.g., Pikwe, Botswana), chromite in layered anorthositic complexes (e.g., Fiskenaessit, West Germany), and chromite seams in dunite lenses (> 3800 Ma).
- Greenstone belts: These belts are rich in mineral deposits associated with various rocks, including ultramafic flows and intrusions (Cr, Ni, Cu), mafic to felsic volcanics (Au, Ag, Cu-Zn), sediments (Fe, Mn, Ba), and granites and pegmatite (Li, Ta, Be, Sn, Mo, Bi).
Mineral Commodities in Nigeria
Nigeria is blessed with approximately 34 solid minerals found in 450 locations across the country. Some of these minerals include gold, iron ore, cassiterite, columbite, wolframite, pyrochlore, monazite, marble, coal, limestone, clays, barites, lead-zinc, among others, distributed within the various metallogenic provinces of the country.
Of these minerals, the government has designated seven as strategic minerals, which are bitumen, gold, coal, iron ore, limestone, lead/zinc ores, limestone, and barites. Other minerals with promising economic potential include tin, tantalite, niobium, gypsum, gemstones, kaolin, among others.
Currently, only a fraction, less than 5%, of these minerals are actively mined, processed, and marketed. Among these are coal, kaolin, barite, limestone, dolomite, gypsum, feldspar, gold, iron ore, lead-zinc, tin, and niobium, as well as tantalum ores.
The remaining 95% of mineral ores, despite being in demand, remain largely untapped. As it stands, solid minerals contribute a mere 3% to the country’s GDP, in stark contrast to oil exports, which account for over 95% of Nigeria’s foreign exchange earnings.
Nevertheless, mineral exploration and production play significant roles in Nigeria’s economy and are considered important for future economic expansion. Despite having a favorable fiscal regime for mining, the development of the mineral sector faces various obstacles.
These challenges include the scarcity of proven mineral reserves, illegal mining activities, inadequate infrastructure, insufficient mineral production and processing capacity, as well as the illicit smuggling of minerals out of the country.
Mineral Resources Classification
- Metallic mineral resources refer to minerals containing raw metal that exhibit a metallic luster and can be melted to form new products. Examples of metallic mineral resources encompass Gold, Silver, Copper, Tin, Iron, Lead, Zinc, Nickel, Chromium, and Aluminum.
- Non-metallic mineral resources are minerals devoid of extractable metals in their chemical composition; they encompass substances such as sand, stone, gravel, clay, gypsum, halite, and Uranium.
- Fuel mineral resources comprise coal, crude oil (petroleum), and natural gas.
Related Article: How Geology Shapes Land Use Planning in Nigeria
Economic Opportunities and Benefits of Solid Minerals Development
The utilization of available mineral resources presents opportunities for ensuring a consistent supply of essential raw materials to our domestic industries crucial for national economic advancement. For instance:
- The oil industry requires minerals like barite and bentonite, essential for various operations.
- The fertilizer industry relies on minerals such as kaolin, phosphate, and marble.
- The iron/steel industry benefits from minerals like marble and refractory clay.
- The aluminum industry depends on bauxite.
- Other mineral-consuming sectors include textiles, ceramics, soap, detergent, glass, and the construction industry.
Developing solid minerals will:
- Support agricultural productivity by providing cheaper domestically sourced fertilizers.
- Facilitate access to new markets due to increased demand, fostering expansion of trade.
- Serve as sources of income, particularly for impoverished communities, as solid mineral mining often creates job opportunities and reduces poverty.
- Generate employment opportunities, particularly for the vast population of young people.
