The investigated sections consist of coarsening upward sequences with thick, dark gray shale at the base, grading upward through siltstones into. The use of foraminifera analysis and palynological data in the lithologic unit of ikem shale has helped in determining the paleoenvironment. Anambra basin showing the extension of ajali sandstone drawn from geological map of nigeria, gsn, 1994. In the eocene, the coastline shape became convexly curvilinear, the longshore drift. Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation. Summarized stratigraphy of the benue trough and anambra basin after. Sedimentation in the anambra basin thus commenced with the campanianmaastrichtian marine and paralic shales of the enugu and nkporo formations, overlaid. The basin is a nwse trending embayment, perpendicular to the main axis of the benue trough and the niger delta basin fig. The study area lies within latitudes 50155 55n and longitudes 70156055e, in the anambra basin. Evidence from field relationship and sedimentological study adeigbe, o. Department of geology, university of nigeria, nsukka, nigeria 2department of physics, university of port harcourt, port harcourt, nigeria abstract data from sixteen deep wells drilled for oil exploration purposes in the anambra basin of southeastern nigeria indicate large variations in temperature gradients and heat flow within the basin. Sequence stratigraphic interpretation of late cretaceousearly. The stratigraphic successions in the bida basin and their relationship to those in the. It is frequently regarded as the northwestern extension of the anambra basin, both of which were major depocentres during the third major transgressive cycle of southern nigeria in late cretaceous times.
The state lies in the anambra basin, the first region where intensive oil exploration was carried out in nigeria. Gravity studies in the bida basin put the maximum thickness of the sedimentary successions at about 3. Outcrops of the formation are well exposed along the long reach of orle stream in auchi as well as road embarkments at ayogwiri, fugar and othame environs in the western flank of the anambra basin, southwestern nigeria. Kinematics of faults and joints at enugu area of the anambra basin d. Kinematics of faults and joints at enugu area of the.
Paleoecology of enugu and mamu formations in anambra basin. Geology and foraminifera analysis of ikem shale and its environs. The southern benue trough and anambra basin, southeastern. The sedimentsinthisregionare partof the asu rivergroupwhichdepositedinthe middle albian. Stratigraphy and sedimentology of the niger delta 7 during the middlelate eocene, sediment was deposited fig. The anambra basin is situated west of the lower benue trough and is often considered youngest formation of the benue trough. Sedimentary succes sions in these basins are of middle mesozoic to recent age.
Due to geographicpositioning,the lowertroughhasinrecenttimes be describedasthe anambra basin due to stratigraphicsimilarities. Paleogeography, sedimentation and tectonics of the upper. The study area lies within the anambra basin and it is made up of. Sedimentological characteristics, provenance and hydrocarbon potential of post santonian sediments in anambra basin, southeastern nigeria. It extends northwestward into the niger valley, northward to the jos massif and northeastward into lafia.
This study aimed at determining the geology and depositional environmental of these formations through field relationship and grain size distribution morphologic studies. Integration of electrical resistivity and induced polarization for subsurface imaging around ihe pond, nsukka, anambra basin, nigeria. Sequence stratigraphic interpretation of late cretaceous. Sedimentology and sequence stratigraphy of the eocene.
Anambra basin has about 6,000 m of sedimentary rocks. The study area lies within the anambra basin and it is made up of enugu shale. The ajali sandstone is a maastrichtian deposit in the stratigraphic units that make up the anambra basin, southeastern nigeria. Anambraimo river basin development authority asked to. Anambra basin located in the south benue trough is a. Biostratigraphy and paleoenvironment of the coniacian. Sedimentology,sequence stratigraphy,anambra basin,nanka formation and eocene. Stakeholders on water have asked the anambra imo river basin development authority to embark on the recycling or reuse of waste water to ensure rapid economic development of its catchment areas. Geological survey editorial standards and stratigraphic nomenclature. Although the basin has not been fully covered by seismic investigations and remains undrilled, both ground and. Biostratigraphy and paleoenvironment of the coniacian awgu formation in nzam1 well, anambra basin, southeastern nigeria. The basin data is derived from a lower resolution grid which has been upsampled using gmt. Postdeformational sedimentation in the lower benue trough, therefore, constitutes the anambra basin. The study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation.
Diagenetic study of sandstone sediments in parts of anambra and afikpo basins, southeastern nigeria article pdf available december 2015 with 434 reads how we measure reads. Anambra basin is a structural synclinal depression and one of the intracratonic basins in nigeria whose origin is related to the separation of africa from south america and the opening of south atlantic ocean ofoegbu, 1982. Ikem and its environment which is located within the anambra basin and have shale as one of its major lithostratigraphic units. The youngest formation within the basin is nsukka formation. U2 1department of petroleum engineering, nigerian agip oil company, port harcourt department of geology, university of port harcourt, port harcourt, nigeria abstract. The structural evolution of the anambra basin has been described by ojoh 1988, popoff 1990, binks and fairhead 1992, obi et al. The basin is bounded to the south by the niger delta basin hinge line. In the paleocene, a major transgression referred to as the sokoto transgression by reijers and others, 1997 began with the imo shale being deposited in the anambra basin to the northeast and the akata shale in the niger delta basin area to the southwest. Anambra basin, geology, depositional environment, mamu.
Introduction this study examines part of the sedimentary units of the eocene nanka formation of anambra basin exposed at lat. Sedimentological attributes and stratigraphic of nanka formation, anambra basin,nigeria acra 2e. M 2 6 2departmentof chemical and geological sciences, alhikmah university, ilorin, nigeria 7 3department of geology, university of ibadan, ibadan, nigeria. Water budget analysis of agulu lake in anambra state, nigeria. Foraminiferal and palynological biostratigraphy of stratigraphic formation, port harcourtenugu expressway, anambra basin, nigeria adiela u. The eastern and western limits of the basin are defined by the abakaliki anticlinorium and ibadan massif, respectively fig. Depositional environments, organic richness, and petroleum.
The identification of additional hydrocarbon reserves to buffer pressure from increasing energy demands in nigeria necessitated the application of sequence stratigraphic framework in the analysis of sedimentary successions in the central portion of southern anambra basin. Cretaceous sedimentation and paleogeography of the central benue. Onuoha department of geology, university of nigeria, nsukka, enugu state, nigeria. Palynology, source rock potential and thermal maturity of. Paleoecology of enugu and mamu formations in anambra basin, southeastern nigeria onuigbo e. Wireline logs and biofacies data from three exploratory wells s1, s2 and s3 were used for the study.
The basins stratigraphy and paleogeography have been studied and described by various workers, such as 2,3,4,5,7,8,9,10,12,14,15,16. The available petroleum systems within the cretaceous interval in the anambra basin will be outlined. This study will contribute additional knowledge to the geology, biostratigraphy and geochemical characteristics of the sediments in the anambra basin. A sequence stratigraphic model for the group was developed by nwajide and reijers 1996, on the basis of stratigraphic analysis of a composite section located at leru, near okigwe. The granulometric study of mamu formation shows fine to medium grains, coarse, medium to fine grain for mamu and ajali formation respectively. Subsurface evaluation of source rock and hydrocarbon. Ladipo ko 1988 paleogeography, sedimentation and tectonics of the. Controversy surrounding the stratigraphy of the anambra basin, depositional. The geologic histories of both the afikpo and anambra basins are thus. Though the anambra river basin was known to be rich in crude oil and gas deposits. Excitement as orient petroleum strikes oil in anambra.
Nigeria is underlain by seven major sedimenta ry basins, viz. A reinterpretation of the depositional environments of the anambra basin succession in the light of modern sedimentological models has necessitated a revision of the late cretaceous paleogeography of southeastern nigeria. Ladtpo department of geology and mlnera sciences university of llorln p. Anambra basin is one of the basins in nigeria, habouring the largest deposit of subbituminous coal and lignite. Pdf geology and depositional environment of campano.
Cretaceous sedimentation and paleogeography of the central benue though. Subsistence of the anambra plate due to folding and uplift of the abakalikibenue fold belt in the santonian stage produces the anambra basin. Preliminary assessment of source rock potential and palynofacies analysis of maastrichtian dark shale, sw anambra basin edegbai, a. The benue trough was formed by rifting of the central west african basement, beginning at the start of the cretaceous period. Oil seepages have also been reported from parts of the basin. Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu. Palynologiacal and paleoenvironmental investigation of the. Orient petroleum resources plc opr was established to harness the vast but mostly untapped mineral, agricultural and human resources, especially hydrocarbon deposits in anambra basin, for the industrialization of the area, improvement of the socioeconomic wellbeing of the people while creating value for the stakeholders. Pdf diagenetic study of sandstone sediments in parts of. Nigeria finds oil and gas in commercial quantities in anambra. Olatunji palystrat limited, ibadan nigeria madukwe, henry y department of geology, ekiti. Ditch cutting samples from an exploratory nzam1 well located in the northwestern part of anambra basin were subjected to lithological. Textural characteristics of the siliciclasts of ajali.
The anambra basin, located in the southern benue trough is a post santonian synclinal sedimentary structure containing over 5,000m thick of upper cretaceous to recent sediments. Anambra basin, enugu shale, rockeval pyrolysis, total organic carbon, source rock, thermal maturation introduction the anambra basin figure 1 which is a cretaceous basin is located in the southern part of the regionally extensive northeastsouthwest trending benue trough. The anambra basin in the west of the lower region is more recent than the rest of the trough, being formed during a later period of compression, but is considered part of the formation. Index map of niger delta and offshore nigeria showing the anambra basin and abakaliki fold belt after doust and omatsola, 1989. Several works have been carried out within the anambra basin. Southern california area office lower colorado region. The basin developed due to the santonian tectonic event which greatly. Download fulltext pdf download fulltext pdf the fish fauna of anambra river basin, nigeria. Accepted 23 august, 2010 structural analysis of joints and fault data obtained from exposures of. Sedimentological characteristics of ajali sandstone at. This could have introduced an accuracy which is beyond the original data. The sedimentary rocks comprise ancient cretaceous deltas, somewhat similar to the niger delta, with the nkporo shale, the mamu formation, the ajali sandstone and the nsukka formation as the main deposits. Palynological and sequence stratigraphy characterization of the earlylate campanian nkporo shale, orekpekpeimiegba area, anambra basin, nigeria adebayo olajide f.
The main oil source formations of the anambra basin, southeastern nigeria. P4and itiowe k5 1,5department of geology, university of port harcourt, port harcourt, nigeria 2 dept. Biostratigraphy and paleoenvironment of the coniacian awgu. The study area lies within the anambra basin which geologically. The marginalshallow marine nkporo group is the basal lithostratigraphic unit of the late campanianmaastrichtian successions of the anambra basin, nigeria fig. Most of the people within the region inhabit the urbanized coastal areas, and the population of these areas is expected to increase by 30% by 2035, to over 4. This page bundles the available data for the anambra basin in the africa. Sedimentology and sequence stratigraphy of the nkporo.
Geology and foraminifera analysis of ikem shale and its. Subsurface evaluation of source rock and hydrocarbon potential of the anambra basin, south eastern nigeria iheanacho princewill ugochukwu dissertation. Department of geology, college of physical and applied sciences, michael okpara university of agriculture, umudike, pmb 7267, umuahia, abia state. Department of geology, ekiti state university, ado ekiti nigeria olaburaimo a. Pdf the fish fauna of anambra river basin, nigeria. The images are hyperlinks and will open up a separate window with a high resolution pdf image of the map. Anambra and bida basins indicates thats the successions of the anambra basin reached up to 8 km thickness compared with an average of 3. Department of geology, faculty of physical sciences, university of benin, benincity, nigeria correspondence. About 30 tcf of gas and 1 bn barrels of crude oil has been found in the anambra river basin in anambra state, the director of engineering standard in the department of petroleum resources dpr, mr patrick onwumere, said in awka. A reinterpretation of the depositional environments of the anambra basin.
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