Geology of Nigeria- Update 2010

Geological Background Today: Tuesday, June 15, 2010 By S. W. Peters INTRODUCTION Geology, the study of rocks, minerals and the physical make-up of the solid earth, determines the environment and natural resources and, thence also, the industrial potentials and wealth of a nation. After climate, geological factors exert, perhaps, the greatest impact on economic activities, since soils, water supply and vegetation are, to a large extent, influenced by the nature of the underlying bedrock. The vast ocean margin that borders Nigeria to the south; the intricate drainage systems that sculpture the physical landscape; the mountainous eastern frontiers; and the wind-swept northern hinterland, with the great plains on the Saharan fringe, are all part of the sur- face geological features that bestow upon Nigeria its unique physical attributes. It could, perhaps, perplex the ordinary mind that, whereas Nigeria exhibits bewildering cultural diversity, the landscape is a continuum in a seamless physical web that unites the physical entity termed Nigeria, regardless of political differences, which are mere human artifact. For example, the Niger-Benue drainage system, which has, over the long geological period of 55 million years, supplied sediments from the Nigerian hinterland for the construction of the petroleum-rich Niger Delta on the coast, has demonstrated the long-term impact of unifying geological processes in a nation with diver- gent human interests. Economic self-sufficiency is also feasible in Nigeria, where the diversity of rocks and mineral wealth, combined with cheap sources of renewable and non-renewable energy, create an enormous industrial potential. The three major rock types - igneous, meta- morphic and sedimentary - abound in Nigeria. Igneous and metamorphic rocks constitute the Pre- cambrian basement complex which is the oldest, crystalline, solid physical foundation of the country. Sedimentary rocks fill up the basins which are vast depressions between basement landmass. The Basement Complex and the sedimentary basins are equally dispersed in Nigeria, with base- ment most extensive in Northern Nigeria; less so in the south-western part of the country; and least along the eastern margin. The sedimentary basins occupy the central x-shaped area in the country; they underlie all of southern Nigeria; and are found in the northwest in Sokoto, and in Borno State and the entire Lake Chad in the north- east. Igneous and volcanic rocks occur mainly on the Jos Plateau, where they are the sources of mineral deposits such as tin, columbite, tantalite, wolframite, monazite and gemstones. Gold, molyb- denite, and non-metallic minerals such as marble, feldspars and talc are among the mineral deposits in the Basement Complex. Apart from oil and natural gas, groundwater and a host of industrial minerals such as barites, lime- stone and clay, the older sedimentary rocks are mineralised with lead and zinc. Coal and lignite occur extensively in the southern and middle Benue Trough, with the lignite belt extending into Delta State. Bitumen or tar occurs in Cretaceous sedi- ments extending from Ogun to Ondo State. Lateritic superficial deposits are ubiquitous in Nigeria. Basement complex rocks are subdivided into migmatite-gneiss complexes; the older metasediments; the younger metasediments; the older gran- ites; and the younger granite alkaline ring

complex- es and volcanic rocks. The migmatite gneiss complex is the common- est rock type in the Nigerian Basement complex. It comprises two main types of gneisses: the biotite gneiss and the banded gneiss. Very widespread, the biotitic gneisses are normally fine-grained with strong foliation caused by the parallel arrangement of alternating dark and light minerals. The banded gneisses show alternating light-coloured and dark bands and exhibit intricate folding of their bands. The migmatite gneiss complex is the oldest basement rock, and is believed to be of sedimentary origin but was later profoundly altered into metamorphic and granite conditions. The older metasediments were also among the earliest rocks to form on the Nigerian Basement Complex. Initially of sedimentary origin, with a more extensive distribution, the older metasediments underwent prolonged, repeated metamor- phism; and now occur as quaitzites (ancient sand- stones), marble (ancient limestones), and other calcareous and relics of highly altered clayey sediments and igneous rocks. Most parts of the Basement complex are under- lain by belts of roughly north-south trending, slight- ly metamorphosed ancient Pre-Cambrian sedimentary and volcanic rocks known as the younger metasediments. The major rock types are ancient shaly rocks which are now referred to as quartz- biotite-muscovite schist. These change laterally into coarse-grained feldspar-bearing micaceous schists. Schists with graphite, phyllites and chlorite are common. Ferruginous quartzites and tale schists also occur. The younger metasediments contain most of the gold deposits in Nigeria in the northwest around Maru and Anka, and at Zuru; near Kaduna, and also at llesha in southwestern Nigeria. Older granites are widespread throughout the Basement Complex and occur as large circular masses within the schists and the older migmite- gneiss complexes. The older granites vary exten- sively in composition. The younger granite complexes in Nigeria are found mainly on the Jos Plateau, forming a distinc- tive group of intrusive and volcanic rocks that are bounded by ring dykes or ring faults. Other occur- rences approximate a north-south belt towards the middle Benue in the south where the ages are younger, and towards Niger Republic in the north where the younger granites are older. There is enormous variety in the granite composition of these rocks.

Sedimentary Basins Today:Tuesday, June 15, 2010 Nigeria is underlain by seven major sedimenta- ry basins, viz: (from the oldest), the Calabar Flank, the Benue Trough, the Chad Basin, SE lullem- menden (Sokoto) Basin, the Dahomey Basin, and the Niger Delta Basin. Sedimentary succes- sions in these basins are of middle Mesozoic to Recent age. Older sedimentary deposits were not preserved, probably because during the Paleozoic - early Mesozoic, what is now Nigeria was a broad regional basement uplift, with no major basin subsi- dence for sediment accumulation. Nigerian basins are broadly divisible into coastal Calabar Flank, Niger Delta, Dahomey Basin and interior basins (Benue Trough, Chad Basin, Nupe Basin, SE lullemmeden Basin). However, the sedimentary successions in these basins are broadly divisible into: (1) basal continental sandstones, siltstones, and mudstones; (2) middle marine shales and limestones interbedded with sandstones and siltstones; (3) upper sandstone sequence that is conti- nental or paralic. Although a tripartite subdivision is also applicable to the Niger Delta, this sequence has been growing seaward with lower marine shales grading through thick ancient coastal sandstones and

shales, into an upper continental sequence. The middle ancient coastal sediments are oil-and gas-bearing.

The Calabar Flank Today:Tuesday, June 15, 2010 The Calabar Flank sedimentary basin that extends from the southern margin of the is Oban Basement complex to the boundary with the e Niger Delta. Here, sudden sediment thickening e demarcates the Niger Delta Basin that formed as the latest of a series of basins in the Benue Trough, diagonally crossing Nigeria from the southwest to ir the northwest. Northwest-southern trending basement structures underlie the Calabar Flank and e define the ltu High and the lkang Trough, thus relating the Calabar Flank to the South Atlantic Cretaceous marginal basins with similar horst-and-graben structures in Angola and Gabon. The sedimentary succession on the Calabar Flank is mostly of Cretaceous age, comprising an ancient river-borne sandstone, the Awi Formation; and the overlying marine Odukpani Group of Albian to Late Cretaceous age. The Odukpani Group comprises the Mfamosing Limestone, the Ekenkpon Shale and the New Netim Marl, which :h are all exposed near the Odukpani local government area headquarters. This is unconformably covered by the Nkporo Shale. Tertiary marine shales and regressive sandstones overlie the Cretaceous succession. The total sediment thickness in the surfaces of the Calabar Flank is over 3500m.

The Benue Trough Today:Tuesday, June 15, 2010 The Benue Trough originated from Early Cretaceous rifling of the central West African basement uplift. It forms a regional structure which is exposed from the northern frame of the Niger Delta and runs northeastwards for about lOOOkm to underneath Lake Chad, where it terminates. Regionally, the Benue Trough is part of an Early Cretaceous rift complex known as the West and Central African Rift System. Tectonic phases and basin development on the Benue :o Trough are divisible into: (1) An Early Cretaceous rift phase with fluviatile and lacustrine deposits; (2) Late Early to Middle Cretaceous phase of rapid basin subsidence and initiation of marine transgression in all rift segments, characterised by submarine gravity flows with megaslumps and turbidites; (3) Prolonged shelf and deep basin deposition especially in the southern part (Abakiliki Rift) under predominantly oxygen-deficient bottom conditions, (4) Tectonism, involving deformation and a- magnetism and the formation of lead-zinc deposits from circulating hot brines, (5) Late Cretaceous post-deformation subsidence with westward displacement of depocentres, especially in the Anambra Basin, where extensive coal forming swamps developed. Although several sub-basins or depocentres have been identified in the Benue Trough on geophysical (gravity) evidence, structurally and in terms of sediments three segments, the Lower, the Middle and the Upper Benue Trough, have been recognised

The Southern Chad Basin Today:Tuesday, June 15, 2010 This is poorly exposed in Nigeria and merges with the Upper Benue Trough. A subsurface basement high, the Zambuk Ridge, separates the Southern Chad Basin from the Upper Benue. The Bima sandstone is the oldest sedimentary deposit in the Chad Basin. A Middle Cretaceous shale-limestone succession, subdivided into the Gongola Formation at the base and the Fika Shale at the top, constitutes the marine and transitional deposits which extend from the Upper Benue into the Southern Chad Basin. The Tertiary Chad Formation is very thick. SE lullemmeden Basin Marine Late Cretaceous - Palaeocene beds in the SE lullemme- den Basin are well exposed into the Sokoto region, in Niger and extending into Mali. Two cycles of dep- osition constitute the Late Cretaceous - Palaeocene marine sequence in SE lullemmeden Basin. The Rima cycle of Late Cretaceous age comprises the Taloka Formation (50m of brown, laminated, paral- lel, bedded, carbonaceous, fine-grained sandstone, siltstones and mudstones), overlain by the Dukamaje Formation (10m of basal bone bed, gyp- siferous, fissile, gray lower and upper shales and middle marl). The Palaeocene Sokoto cycle com- prises the Wurno Formation (20m of soft, tabular mudstone, muddy siltstones, and fine-grained sandstones at the base which grades upward into the Dange shale (10m thick), and the Kalambaina Formation (12m of nodular, marly limestone which becomes shaly at the top). The Gwandu Formation above is a ferruginious sandstone of continental origin.

Dahomey Basin Today:Tuesday, June 15, 2010 This is an arcuate coastal basin, the onshore parts of which underlie the coastal plains of southwest Nigeria, Benin and Togo. A faulted basement high, the Okitipupa Basement Ridge separated the Dahomey Embayment from the Benue Trough until the late cretaceous subsidence and marine transgression united both basins. From available subsurface stratigraphic information, it is apparent that some of the basement blocks underlie the Dahomey Embayment are displaced towards the NNE-SSW basin axis as well as towards the offshore. At the base of the sedimentary succession is the bitumen- bearing sand of enormous economic potentials. Shallow boreholes have penetrated continuous Late Cretaceous marine shales which are correlat- ed with the Nkporo Shale Formation. Nearer the coast and offshore, the marine beds are older. Lower Tertiary marine units (Palaeocene Ewekoro Limestone Formation and the Eocene phosphatic Oshosun Formation) are exposed in quarries at Shagamu and Ewekoro in Ogun State, and at Onigbolo and Tabligbo in neighbouring Benin Republic. Although the younger Tertiary strata exposed along the coast are non-marine, marine Miocene deposits (ljebu Formation, Afowo Beds) are known in the offshore subsurface. Niger Delta In its sedimentary succession, the Niger Delta comprises a lower marine unit, the Akata Group; a middle coastal unit, the Agbada Group; and an upper continental sequence, the Benin Group. Each of these units represents an enormous geologic age span, because of the advancement of the Niger Delta oceanward. Ancient marine shales in the Niger Delta provide excellent source rocks for petroleum, whereas the sands are the reservoirs where oil and gas accu- mulation took place; trapping is mostly along faults. CONCLUSION

Geologically, Nigeria comprises crystalline basement rocks and sedimentary basins, almost in equal proportions. The ages of the basement rocks span Precambrian to early Palaeozoic, having been consolidated during the Pan-African. The sedimen- tary basins are of Cretaceous to Recent age. While road construction and maintenance are compara- tively cheaper on basement terrain, the sedimenta- ry basins present enormous difficulties and lead to high construction costs, the situation being more challenging in the Niger Delta. However, the geol- ogy of Nigeria provides a unique source of petrole- um and mineral wealth, and unparalleled opportuni- ties for rapid economic development.

Energy Resources and Energy Policy Today:Tuesday, June 15, 2010 INTRODUCTION Nigeria is Africa's energy giant. It is the continent's most prolific oil- producing country, which, together with Libya, accounts for two- thirds of Africa's crude oil reserves. It ranks second to Algeria in natural gas. Most of Africa's bitumen and lignite reserves are found in this country. In its mix of conventional energy reserves, Nigeria is simply unmatched by any other country on the African continent. It is not surprising, therefore, that energy export is the mainstay of the Nigerian economy. Also, primary energy resources dominate the nation's industrial raw materials endowment. Nigeria's industrialisation depends largely on how its energy resources (oil, gas, bitumen, coal, lignite) are har- nessed either as fuel or as industrial feedstock. Over-dependence on oil is evident from the fact that oil revenue, as a percentage of the nation's total export earnings, soared from 13.5 per cent in 1956 to 96.5 per cent in 1979. Since then, crude oil production has accounted for 30 per cent of GDP and about 80 per cent of total government revenue. (ECN, 1992). With the completion of the Oso export-marketing condensate facility, and of Phase 1 of Nigeria's petrochemical project, as well as the commencement of the export of liquefied natural gas to Europe, there is no doubt that the energy sector will continue to be an important factor in the Nigerian economy for the foreseeable future. In keeping with its policy of regional cooperation with sister African nations, Nigeria recently entered into negotiations with five West African states under the West African Gas Reserves Project. These are the Republics of Ghana, Togo, Benin, Niger and Cote d'lvoire. The aim is to ensure that in the event of serious power interrup- tion in those countries, Nigeria's National Electric Power Authority (NEPA) will switch them on. Nigeria already supplies electricity to Chad Republic. Also, under the West African Gas Pipeline Project, Nigeria is to supply gas regionally.

Domestic Energy Scene Today:Tuesday, June 15, 2010 Availability of reliable power supply is part of the enabling environment for industrialisation and is, therefore, a deliberate national policy. To attract industrial development to all parts of this vast and populous country, many major towns have been linked to the national grid. The installed electricity- generating capacity in the country stands at 5,700 MW, of which the average plant capacity in 1992 was 3,200 MW, while the peak demand for the year was 2,362 MW. Generally, there has been a phenomenal growth in energy consumption which surged from 23 million tons of oil equivalent in 1970 to nearly 60 million tons in 1990. Commercial energy consumption has also witnessed spectacular growth, in which petroleum products account for about 70 per cent, natural gas 25 per cent, electricity 5 per cent, and coal one per cent.

Per capita primary energy consumption is about 480 oil equiva- lent, which falls to 301 if traditional energy sources like firewood and charcoal are not considered. Natural gas and hydroelectricity provide the sources of the power generated by NEPA. Private power plants are also operated as stand-by generating units in the event of power outages from NEPA. The oldest generating station in the country is the Kainji Hydroelectric Power Station, located on the River Niger, upstream from Jebba. This station was completed in 1968. With the traditional generating units added subsequently, the total capacity at the Kainji station is 760 MW. At Jebba, another hydro station is located, with a generating capacity of 540 MW. A modern hydroelectric station was commis- sioned in 1990 at Shiroro Gorge on the Kaduna River, near Minna in Niger state. The Shiroro station has a maximum capacity of 600 MW. The earliest gas station in the country is the Afarn Thermal Power Station, built in 1963 with a total capacity of 696 MW. In Lagos, the thermal power station at Egbin is the largest single station in the country and in Africa, with a capacity of 1320 MW. Located directly on the Niger Delta, the Sapale Thermal Station is designed to use both oil and gas, and can produce up to 720 MW at full firing. The Delta (IV) Thermal Station at Ughelli, Delta state, has a capacity of 600 MW, and was commissioned in 1991. Two new power stations are being planned for Zungeru (950 MW) and Abuja, the Federal Capital.

Propile of Available Energy Resources Today:Tuesday, June 15, 2010 Petroleum: Reserves in Nigeria at the moment are estimated at over 23 billion barrels of crude oil and 260 trillion cubic feet of natural gas. The natu- ral gas reserve amounts to three times the total crude reserves. From a modest initial output of 5,000 barrels per day (bpd) in 1958 when production first began, Nigeria's production rose rapidly, to 2.4 million bpd in 1979. Nigeria's petroleum resources lie mostly in the Niger Delta, the central coastal plain of southern Nigeria; at the continental margin; and at the small offshore portion which extends into Equatorial Guinea and Carneroun, where the delta is known as the Rio del Rey Basin. So far, 29.2 billion barrels of crude oil have been discovered in the delta, 23.3 billion barrels in the Nigerian sector, 937 million barrels in the Rio del Rey Basin, and 45 million barrels of condensate in Equatorial Guinea. Ancient delta front sands of Late Cenozoic age account for the bulk of the Niger Delta oil fields. (Whiteman, 1982). So far, about 870 oil fields have been discovered with over 4000 oil wells, the bulk of which are not yet producing. Among the giant fields is the Edop field, the largest offshore platform in Nigeria which can handle 180,000 barrels per day, but will increase production to 250,000 barrels per day. Other large fields include Janes Creek, Imo River, Nembe, Meren, Delta south and Okan. A major boost to the Nigerian petroleum sector was the coming on stream recently of the Oso condensate project. With 500 million barrels of condensate and a production capacity of 100,000 bpd, the Oso field, which is offshore Akwa lbom State and is operated by the Nigerian National Petroleum Corporation/ Mobil joint venture, will generate eleven billion dollars to the Nigerian government, and allow the reinjection of all the associated gas produced by Mobil in the eastern offshore delta. Over 70 per cent of the associated gas in Nigerian oil fields is flared; and less than 30 per cent is used for power generation and by industries. Shell, Exxon, Mobil, Chevron, Agip, Elf, and Texaco are the main operators. Since petroleum is a wasting asset, the NNPC has encouraged exploration in other Nigerian sedimentary basins, notably the Borno and Anambra Basins, and the deep water Niger Delta. With their sedimentary sequences, the Borno and Anambra Basins have been drilled, though without success so far. The deeper offshore Niger Delta is the most promising petroleum frontier

province, where water depths between 200 and 1,500m have been allo- cated for prospecting, with encouraging recent discoveries

Coal and Lignite Today:Tuesday, June 15, 2010 Like other parts of the world, coal is the oldest commercial fuel, dating in Nigeria from 1916 when 24,000 tons were produced. Production peaked at near one million tons in 1959, before declining to the present insignificant level. This is due to the reduction in the demand for coal arisina from dieselisation of rail transportation, and switching from coal to gas for thermal power generation. Nevertheless, Nigeria's coal reserves are large, over 2 billion metric tonnes, of which 650 mil- lion tonnes are proven. If fully revitalised, the coal industry could fetch up to 5 billion Naira in export earnings. Coal production is from the Cretaceous Anambra Basin which extends to Dekina in the northern part of the basin in Benue State and to Okigwe in the south. The coal in this basin is sub- bituminous and occurs principally at two levels, the lower coal measures (Mamu Formation) and the upper coal measures (Nsukka Formation). From north to south, the reserves from seams over one meter thick, are (in million tonnes); Ogboyoga (100), Okaba (70), Orukpa (60), Ezimo (50), and Enugu (50) (FRN, 1987). Coal seams also occur at Gombe in Gombe State. Mine production capaci- ties after full rehabilitation and privatisation could attain the following levels: Onyeama and Okpara (150,000-400,000 tonnes/year), Owukpa (2,500 tonnes/year) and Okaba (15,000-300,000 tonnes/ year). Nigerian subbituminous coal has a high calorific value (5,000-6,000 cal/g or 5500-6500 airdried), low ash and low sulfur contents, with good storage characteristics (Afonja, 1979). In the Lafia-Obi area of Nassarawa State, good quality cooking coal has been discovered which is suitable for use in the iron and steel industry. If utilised, the Lafia-Obi coal would save the country the high cost of importing cookable coal. Since the Nigerian Coal Corporation has lost nearly all its tra- ditional customers, notably railways and power authority, a recent drive to market its coal overseas offered some hope of recovery. European buyers in Italy and the United Kingdom have started import- ing Nigerian coal, because its low sulfur content is environmentally acceptable. As already noted, Nigeria has the largest lignite deposit in Africa, with reserves of about 50 million tonnes. The Nigerian lignite belt, of midTertiary age, extends from Oriu in the south-east, through Urnuezeala, Umuahia, Nnewi, Oba, in a 20 to 40km - wide belt across the Niger, to Ogwashi, Asaba, Mgbiigliba and Adiase-Uti in Delta State. It has not yet been exploited.

Bituminous Sand Today:Tuesday, June 15, 2010 About 31 billion barrels of heavy crude oil is held in bituminous sand deposits in south-western Nigeria. The bituminous sand deposits occur in 12km - wide belt that extends from ljebu-Ode in Ogun State, through Ondo State, to Edo State. It lies in the Upper Cretaceous sequence of the Abeokuta Formation in the eastern Dahomey Basin. Nigeria imports an average of 50,000 barrels of heavy crude oil a day from Venezuela for producing "base oil" which is used to blend with lubricants and greases in Kaduna Refinery. There is, therefore, a need to extract heavy oil from the Ondo deposit for the refinery and for bitumen. Hydropower:Hydro-electricity accounts for nearly half of the power supply in Nigeria, and more stations are being planned. The River Niger has been excessively damned in Mali, Niger and

Nigeria. Therefore, to continue to depend on it for electricity, especially considering its droughtprone upper basin that traverses the Sahel, is no longer strategic. Apart from the River Niger, other hydropower stations have been proposed: Makurdi on the River Benue (1000 MW); Yola, also on the Benue (600 MW); Katsina North on the River Katsina (160 MW); Beli SE on the Taraba River (240 MW); and Ikorn on the Cross River (400 MW). Other potential hydro-electric dam sites are: Afikpo (180 MW); Bembu (130 MW); Garin Ladi (13 MW); Richa (70 MW); Sarkin (50 MW); Guadjikiri (40 MW); Kuru (40 MW); and at Gwaram, Kasambia and lfon, where each station could generate 30 MW.

Biomass Energy Today:Tuesday, June 15, 2010 Biomass is the most com- monly used source of rural energy in Nigeria because fuel-wood is the cheapest and most accessible source of fuel even in urban households. In fact, fuel-wood is the traditional fuel source, which, in spite of the availability of conventional domestic fuels, remains in very high demand at the expense of Nigerian forests. Even in the ecologi- cally fragile Sudan-Sahel belt of northern Nigeria where desertification poses a serious threat to man and the environment, there are hardly any large scale shifts from traditional biomass energy to mod- ern fossil fuels. Supplies appear to be diminishing, overall, in the face of increasing consumption, and massive forest/woodland and farm tree losses. The human and environmental cost of obtaining and consuming fuel-wood appear to be increasing. The total annual consumption of fuel-wood in the country in 1987 was estimated at about 80 million cubic metres. Because of the inefficiency of the local fuel-wood stoves, the bulk of the energy avail- able from wood-burning was lost, amounting to 97 per cent. In terms of the average per capita wood consumption, urban dwellers use about 360 kg/per- son, while in the rural areas the average per capita consumption has been put at 511.2 kg/person or 0.71m of solid wood. Communal bushes constitute the largest source of wood for fuel, a situation that engenders severe deforestation. In extremely stressed environments in the Sudan-Sahel region, grasses and cow dung are used for fuel because of wood- deficiency. Wood-processing mills provide a small source of wood energy in parts of southern Nigeria. Fuel-wood plantations are of negligible importance even though the first such plantation was established in Lagos in 1912. There were oth- ers at lbadan and ljebu-Ode. More fuelwood plan- tations are needed in the country to conserve the natural forests. Another solution, recently embarked upon, is to transport coal from the south to the north, and market it there as an alternative to firewood. Solar Energy: Situated approximately between 4°N and 13°N, Nigeria is geographically favourably located to tap unlimited solar energy, the most dependable renewable energy source. It has been estimated that a yearly average of about 2,300 kwh/m2 of solar energy tails on a horizontal surface in Nigeria, and that in Lagos the intensity of solar radiation is about 930w/m2 on a clear sunny day. (FMST, 1987). At the International Institute for Tropical Agriculture at lbadan, incident solar energy varies from S.lkwh/malday during the least favourable day in August to 5.8kwh/m~/day in March and April. What Nigeria requires is an affordable solar energy technology and cheap appliances. Potential solar energy applications in the country include drying of agricultural products (the traditional use), water pumping, air-conditioning and refrigeration, electricity generation, desalination and distillation, cooking and water heating.

Energy Sources as Industrial Feed Stock Today:Tuesday, June 15, 2010 Nuclear Energy: Nuclear power is one of the most feasible alternatives to fossil fuels in the developed countries, except for the heavy stigma of its deadly 'association with nuclear weapons and wastes. Such disasters as Three Mile Island (U.S.A.) and Chernobyl (Russia), also attest to the dangers. However, its prospect in Nigeria is as yet a curiosity. Economic uranium deposits are yet to be established, in the first instance. So far, uranium traces have been found only near Gombe in Gombe State and Ugep in Cross River State. In Sokoto and Ogun states, radioactive phosphate grains occur. However, given the widespread peaceful applications of nuclear technology in agriculture and animal production, medicine, mineral exploration and environmental protection, Nigeria is keenly interested in nuclear science and technology ENERGY SOURCES AS INDUSTRIAL FEED STOCK Crude oil, natural gas, coal and lignite serve a dual function as fuels and as industrial feedstock. It is therefore pertinent to examine briefly the later applications of fossil fuels in Nigeria. In a typical sense in which oil and gas are used in modern industrial civilisation as source of fuel, food and fibre, Nigeria is developing these down stream aspects of its petroleum industry. There are three refineries in the country at Port Harcourt, Warri and Kaduna, with a combined capacity of 445,000 barrels per day. Having met its domestic fuel needs, Nigeria has made plans to build an export efinery in the country. It was to ensure the availability of basic industrial raw materials that the nation's first petrochemical complex began operation in 1988, when the polypropylene plant which is attached to the Warri refinery was commissioned. This plant also produces carbon black for the manufacture of tyres and other products. Another plant, which is attached to the Kaduna refinery, produces Linear Alkyl Benzene. The Eleme Petrochemical Complex, which is under construction near Port Harcourt, will supply ethylene and propylene utilising natural gas, used for the manufacture of fertiliser by a company also in Port Harcourt. Coal and lignite are potential raw materials for the chemical industry. Plans are underway to utilise the local coal in the iron and steel industry.

Energy Policy Today:Tuesday, June 15, 2010 In his foreword to the Proceedings of the Energy Policy Conference held in 1978, President Olusegun Obasanjo, then the military Head of State, declared as follows: "Energy, in all its ramifications, has finally emerged in our consciousness as a crucial element in this unavoidable industriali sation and socio-economic development process. " When eventually a copy of the first Policy Guidelines on Energy for Nigeria was presented in 1987, it had as its cardinal goal, the achievement of a good mix in the development of Nigeria's energy resources, in an environmentally acceptable manner that would guarantee national self sufficiency and security. The objectives of the guidelines include the development and maintenance of a regular inventory of the energy resources in Nigeria. It also aims at ensuring continuity and self-sufficiency in energy supply in the short, medium, and long- term, at economically favourable costs. The guide lines took cognisance of the need to protect the quality of the environment and the population from the hazards of energy exploitation and utilisation. It further aims at improving the

nation's technical capabilities in the energy sector for State security, self-reliance and economic competitiveness. Furthermore, the national policy guidelines aim at providing a co-ordinated framework for the imple- mentation of energy policy issues. To this end, the Energy Commission of Nigeria was set up, in addi- tion to the government-funded centres for energy research at the Ahmadu Bello University, Zaria, the University of Nigeria, Nsukka and at the Obafemi Awolowo University, lleife. Several strategies have also been adopted towards achieving the main policy thrust of diversifying the economy to guarantee the full development of all available energy resource potentials in the country. Priority attention has been given to increased utilisation of natural gas for industrial and domestic (household) use. The nation's energy policy also recognises the crucial importance of rural electrification as a means of rapid rural development and protecting the Nigerian nvironment, by bringing an alternative energy source to the grassroots.As noted by the then Secretary of Power and Steel in his 1992 Ministerial Press Briefing. The present Administration is desirous of leaving behind a commitment to a policy of integrated rural development as a key to national development. Basic to this is the provision of electric power in the rural areas; an objective which the Rural Electrification Programme is designed to achieve. Finally, regional and international co-operation in energy matters is a deliberate goal of the Nigerian Energy Policy, the primary and immediate focus of which is the Economic Community of West African States (ECOWAS), which is experiencing severe energy crisis. To alleviate the situation among the countries of ECOWAS, the strategies adopted by Nigeria include coordination of energy planning, research, information and technological exchange on a regional scale; minimising the high cost of energy importation into member States by facilitating the regional distribution of petroleum products; and encouraging the extension of the national grids of neighbouring countries to optimise the utilisation of regional hydroelectricity and other energy potentials. CONCLUSION Nigeria's energy mix and the potentials of the conventional sources of electricity generation and fuel supply have been proven, but have remained largely untapped. Cheap energy supply is the greatest stimulus for industrialisation. Hence, investments, diversification, deregulation and the creation of regional power supply companies are needed to clear energy supply bottlenecks.

Non-Metallic Mineral and Industrial Materials Today:Tuesday, June 15, 2010 Crushed rock, gravel, sand and clay are ubiquitous building materials widely used for rural and urban dwellings, and in the construction industry for civil engineering works such as roads, buildings, bridges and dams. The Basement Complex furnishes a rich source of crushed rock which is augmented with basalt, dolerite and limestone in some places. Laterite is a common building and road-surfacing material. River gravel of various sizes are widely available as aggregates and building material, especially in Akwa lbom and Cross River states. Sand of glass-making quality has been found and assays in many parts of the country (Odukwe, 1981). In Port Harcourt, the Trans-Amadi sands contain over 99 per cent Silicon oxide (S,0g) and at Ughelli, another clean coastal plain, sand deposit assays 97 per cent Silicon oxide (S,0j. Both

sands are used for the manufacture of bottles and window glass. The West African Glass Company at Aba utilises a local sand deposit. Many other glass sand deposits are known especially along the coast. Reserves are inexhaustible since full industrial use has hardly begun. Clays of various kinds and grades abound throughout Nigeria's sedimentary basins and on the basement. Nigeria has a rich traditional pottery industry that dates from the Stone Age. In all parts of the country, native pottery is a vibrant traditional art form and an established cottage industry for earthenwares. Modern industrial uses of clay for ceramics and bricks obtain throughout the country. Ceramic works at Abeokuta (Ogun State), Ikorodu (Lagos State), Okigwe (Imo State), Umuahia (Abia State) and Suleja in Niger State produce glazed wares from local kaolin. Refractory clays for refractory bricks have been proven at Onibode near Abeokuta where the refractoriness is very high at about 1,750°C. In Enugu, beneath the coal seams, are vast deposits of other fire clays, with reserves of about 130 million tonnes. Other major clay deposits occur in Akwa lbom (Etinan, ltu, Onna, Uyo); Anambra State at Ozubulu (3.5 million tonnes) and Ukpor (4.2 million tonnes); Edo/Delta States at lgoriakhi (over 14.0 million tonnes); Imo/Abia States (over 2.0 million tonnes) at lgbere and Ogbuebule; Kaduna State (over 5.3 million tonnes) at Miraba- Rido and Kaohia; Katsina State (3.4 million tonnes) at Kankara; Ogun State (over 2.0 million tonnes) at Oke-Eri and Illefun Hill; large deposits in Ondo State; over 18 million tonnes in Plateau State at Nafuta, Worrom, Major Porter and Sabon Gida; and, in Sokoto State 2.0 million tonnes of pisolitic clays occur at Girl, and clay bricks are made at Wurno (RMRDC, 1989). Bentonitic clays, which are used for drilling mud, were first produced in Bende in Abia State in 1961-62. Recent investigations by the Nigerian Mining Corporation, aimed at locally sourcing the enormous amount of bentonite imported into the country by the petroleum industry, established the existence of bentonitic clay reserves of over 700 million tonnes in the country, with the largest single deposit atAfuze in Edo State holding 70-80 million tonnes. Limestone and gypsum, the principal raw materials for cement manufacture, are very essential for a rapidly growing nation like Nigeria. And, indeed, cement is in very high demand in the country. While limestones abound in Nigeria more than in any other West African country, gypsum and other salts have not been found in commercial quantity. The nearest potential source of gypsum for Nigeria could be Mali Republic, where millions of tonnes of mineable salts occur at Agorgott. As for clinker (processed limestone for cement), Nigeria could export this material to Cameroun, which at present obtains its clinker from Europe. Seven out of the eight cement factories in Nigeria are sited close to limestone deposits, except the plant at Okpilla in Edo State, which uses marble. The cement factory at D'Onigholo in Benin Republic is jointly owned by Benin (52 per cent) and Nigeria (46 per cent); It is located on the Ewekoro limestone deposit which extends from Ogun State in Nigeria to as far as Ghana. Other cement factories in Nigeria are located atAshaka, Yandev, Nkalagu, Shagamu, Okpilla, Ewekoro, Sokoto and Calabar. The limestone at Mfamosing, near Calabar, is the largest and the purest deposit in Nigeria. It is about 50m thick, at the quarry site. West of Calabar, another carbonate body occurs in the subsurface that is 450m thick. The Calabar flank is the main carbonate province in Nigeria, with well-developed tropical karsts and caves (Reiljers and Potters, 1987). The Mfamosing limestone has over 97 per cent limestone (CaC03). It is used by the Delta Steel plant at Aladja as a flux- ing agent and for making hydrated lime. Marble is found in the Basement Complex and is quarried at Jankura near Lokoja, at Ubo near Okene, and at Okpilla. The Jankura marble is utilised as decorative marble by the Nigerian

Marble Industries. Dolomitic marble deposits are exploited at lgbeti in Oyo State and at Kwakuti in i Niger State. Other deposits are at Elehu in Kwara State, Kobe in Benue State, Muro Hill in Plateau State, and at Burum and Taka Lafia in the Federal Capital Territory. Feldspar, a mineral that is used locally in the ceramic and glass industries, occurs abundantly in the Basement Complex. Economic deposits are found in the granitic intrusives in the basement and especially in pegmatites where potash feldspar is the commercial type. Important sources of feldspar rich pegmatites occur in Kwara and Kogi States and also extensively around Osogbo in Osun State.Near Oshogbo, potash feldspars attain lengths of 0.9m, but around Ijero in Ekiti state, gigantic crystals are up to 1.2m long. Feldspar-rich pegmatities are common in the Qwozan area of Borno State and in parts of Adamawa/Taraba states. Although rock salt has not been found in Nigeria, highly saline brines in the Benue Trough provide potential local sources of salt except, of course, the open ocean and there are as yet no salinas on the Nigerian coast.But along the Benue Trough brines, saltsprings, saltponds and shallow subsurface brine pools are commonly associated with lead-zinc deposits. Salt concentrations are up to 1.5 per cent in the Ikom area and 8.6 per cent at Okpoma in Cross River State, where the richest occur. At Uburu-Okposi in Abia State, the salt con- centration is up to 5 per cent and 5 - 6 per cent at Ameri.nearAbakaliki. Further north, in Nassarawa State (Keana, Awe) and in Taraba and Adamawa States, there are other brine fields. Geophysical investigations by the Geological Survey of Nigeria and other organisations aimed at locating salt domes in the Benue Trough, have so far not found any. Therefore, the establishment of local, modern and large-scale salt industry in Nigeria is still a dream not realised. However, at Okpoma, Ikom, Uburu, Okposi, Abakaliki and in the Keana/Awe areas, the local people have established a long tradition of winning salt from their brines. Among the metallurgical and refractory minerals needed for the reduction of ores from their metallic state and for making resistant materials for high temperature metallurgical furnace, which will be required by the local metallurgical industries (e.g. iron steel plant), only flourspar and graphite seem to have commercial prospects in Nigeria. The lead-zinc lodes in the Benue Trough carry small amounts of flourspar which also occur in tin veins in the younger granites. Impure graphite is known in the younger metasediments near Birnin Gwari in Kaduna State, Taraba and Adamawa States, at Hayna (Ningi) in Bauchi State and in the Obudu area of Cross River State. Other refractory minerals, such as sillimanite and kyanite, occur in the Birnin Qwari schists, while sillimanite is found in the vicinity of lbadan. Other industrial and manufacturing materials such as mica, talc, asbestos and barytes also occur in the country. There is a mica deposit around Egbe in Kwara and Kogi States which was mined in the past. The crystal size of Nigerian mica is often not large enough to be economic. Low grade talc occurs in schists near lbadan (Oyo State), llesha (Osun State), Abuchi in Niger State, Zonkwa in Kaduna State and at Isanlu in Kwara State. Asbestos exists at Shemi in Kaduna State, and a large deposit occurs at Chafe in Sokoto State. Barytes, a major weight filler for drilling mud, occurs in veins, up to 1.8m thick in association with lead- zinc deposits in Cross River, Benue, Plateau, Taraba and Adamawa States. Major baryte occurrences in Nigeria are at Lefin in Cross River State, at Aloshi, Akuri, Wuse, Azara and Gbane in Plateau State. Keana in Nassarawa State and at Ibi and Durngel in Taraba and Adamawa States.

At Azara, good quality baryte reserves of about 70,000 tonnes have been proven by the Nigerian Mining Corporation. Finally, the Nigerian basement also holds some prospects for gemstones. In Nassarawa, Plateau and Kaduna States, aquamarine, emerald, sap- phire, ruby, topaz, tourmaline, zircon and almandine have been won from pegmatites. CONCLUSION The solid mineral sector offers viable orosoects for mining, mineral processing and the manufacture of a host of intermediate raw materials for local industries as well as for foreign exchange earning. It has created the opportunity for diversifying Nigeria's hitherto petroleum dominated economy. Intensive mineral exploration and appraisals are needed to attract foreign investors into the mining of gold, tin, columbite, lead and zinc. Moreover, coal, bitumen, barytes, feldspars and a host of other industrial minerals are awaiting exploitation by potential investors.