The ajali sandstone is a maastrichtian deposit in the stratigraphic units that make up the anambra basin, southeastern nigeria. Geological survey editorial standards and stratigraphic nomenclature. P4and itiowe k5 1,5department of geology, university of port harcourt, port harcourt, nigeria 2 dept. The study area lies within the anambra basin which geologically. Stratigraphy and sedimentology of the niger delta 7 during the middlelate eocene, sediment was deposited fig. Sedimentology,sequence stratigraphy,anambra basin,nanka formation and eocene. Several works have been carried out within the anambra basin. 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. The stratigraphic successions in the bida basin and their relationship to those in the. Sedimentological characteristics of ajali sandstone at. The use of foraminifera analysis and palynological data in the lithologic unit of ikem shale has helped in determining the paleoenvironment. 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.
Sequence stratigraphic interpretation of late cretaceous. 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. Accepted 23 august, 2010 structural analysis of joints and fault data obtained from exposures of. Index map of niger delta and offshore nigeria showing the anambra basin and abakaliki fold belt after doust and omatsola, 1989. U2 1department of petroleum engineering, nigerian agip oil company, port harcourt department of geology, university of port harcourt, port harcourt, nigeria abstract. Ikem and its environment which is located within the anambra basin and have shale as one of its major lithostratigraphic units. Textural characteristics of the siliciclasts of ajali. Excitement as orient petroleum strikes oil in anambra. Kinematics of faults and joints at enugu area of the. Pdf the fish fauna of anambra river basin, nigeria. This study aimed at determining the geology and depositional environmental of these formations through field relationship and grain size distribution morphologic studies.
The southern benue trough and anambra basin, southeastern. Biostratigraphy and paleoenvironment of the coniacian. Pdf diagenetic study of sandstone sediments in parts of. Department of geology, ekiti state university, ado ekiti nigeria olaburaimo a. Postdeformational sedimentation in the lower benue trough, therefore, constitutes the anambra basin. Sedimentary succes sions in these basins are of middle mesozoic to recent age. The marginalshallow marine nkporo group is the basal lithostratigraphic unit of the late campanianmaastrichtian successions of the anambra basin, nigeria fig. Controversy surrounding the stratigraphy of the anambra basin, depositional. Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation.
Anambra basin showing the extension of ajali sandstone drawn from geological map of nigeria, gsn, 1994. The study area lies within the anambra basin and it is made up of enugu shale. Geology and foraminifera analysis of ikem shale and its. 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. Sedimentation in the anambra basin thus commenced with the campanianmaastrichtian marine and paralic shales of the enugu and nkporo formations, overlaid. 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.
Download fulltext pdf download fulltext pdf the fish fauna of anambra river basin, nigeria. Water budget analysis of agulu lake in anambra state, nigeria. M 2 6 2departmentof chemical and geological sciences, alhikmah university, ilorin, nigeria 7 3department of geology, university of ibadan, ibadan, nigeria. Wireline logs and biofacies data from three exploratory wells s1, s2 and s3 were used for the study. Sedimentology and sequence stratigraphy of the eocene. 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.
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. The youngest formation within the basin is nsukka formation. Depositional environments, organic richness, and petroleum. 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. Kinematics of faults and joints at enugu area of the anambra basin d. This page bundles the available data for the anambra basin in the africa. 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. Department of geology, faculty of physical sciences, university of benin, benincity, nigeria correspondence. Though the anambra river basin was known to be rich in crude oil and gas deposits.
The basin is a nwse trending embayment, perpendicular to the main axis of the benue trough and the niger delta basin fig. The sedimentsinthisregionare partof the asu rivergroupwhichdepositedinthe middle albian. The study area lies within the anambra basin and it is made up of. The eastern and western limits of the basin are defined by the abakaliki anticlinorium and ibadan massif, respectively fig. Sedimentological characteristics, provenance and hydrocarbon potential of post santonian sediments in anambra basin, southeastern nigeria. A reinterpretation of the depositional environments of the anambra basin. Ditch cutting samples from an exploratory nzam1 well located in the northwestern part of anambra basin were subjected to lithological.
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. 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 basin is bounded to the south by the niger delta basin hinge line. Anambra basin, geology, depositional environment, mamu. Anambraimo river basin development authority asked to. 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. Sequence stratigraphic interpretation of late cretaceousearly. This could have introduced an accuracy which is beyond the original data. Palynological and sequence stratigraphy characterization of the earlylate campanian nkporo shale, orekpekpeimiegba area, anambra basin, nigeria adebayo olajide f. Biostratigraphy and paleoenvironment of the coniacian awgu. The basin data is derived from a lower resolution grid which has been upsampled using gmt. Paleoecology of enugu and mamu formations in anambra basin, southeastern nigeria onuigbo e. 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. Department of geology, college of physical and applied sciences, michael okpara university of agriculture, umudike, pmb 7267, umuahia, abia state.
The granulometric study of mamu formation shows fine to medium grains, coarse, medium to fine grain for mamu and ajali formation respectively. In the eocene, the coastline shape became convexly curvilinear, the longshore drift. The images are hyperlinks and will open up a separate window with a high resolution pdf image of the map. Sedimentological attributes and stratigraphic of nanka formation, anambra basin,nigeria acra 2e. The benue trough was formed by rifting of the central west african basement, beginning at the start of the cretaceous period. Southern california area office lower colorado region. Anambra basin located in the south benue trough is a. Olatunji palystrat limited, ibadan nigeria madukwe, henry y department of geology, ekiti. Preliminary assessment of source rock potential and palynofacies analysis of maastrichtian dark shale, sw anambra basin edegbai, a. Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu.
It extends northwestward into the niger valley, northward to the jos massif and northeastward into lafia. Palynology, source rock potential and thermal maturity of. 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. Integration of electrical resistivity and induced polarization for subsurface imaging around ihe pond, nsukka, anambra basin, nigeria. The main oil source formations of the anambra basin, southeastern nigeria.
Foraminiferal and palynological biostratigraphy of stratigraphic formation, port harcourtenugu expressway, anambra basin, nigeria adiela u. 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. Subsurface evaluation of source rock and hydrocarbon potential of the anambra basin, south eastern nigeria iheanacho princewill ugochukwu dissertation. Nigeria is underlain by seven major sedimenta ry basins, viz. The state lies in the anambra basin, the first region where intensive oil exploration was carried out in nigeria. The geologic histories of both the afikpo and anambra basins are thus. 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. Oil seepages have also been reported from parts of the basin. This study will contribute additional knowledge to the geology, biostratigraphy and geochemical characteristics of the sediments in the anambra basin. Subsurface evaluation of source rock and hydrocarbon. Sedimentology and sequence stratigraphy of the nkporo. Evidence from field relationship and sedimentological study adeigbe, o. 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.
Anambra and bida basins indicates thats the successions of the anambra basin reached up to 8 km thickness compared with an average of 3. The investigated sections consist of coarsening upward sequences with thick, dark gray shale at the base, grading upward through siltstones into. The available petroleum systems within the cretaceous interval in the anambra basin will be outlined. The anambra basin is situated west of the lower benue trough and is often considered youngest formation of the benue trough. The study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation. Cretaceous sedimentation and paleogeography of the central benue though.
Nigeria finds oil and gas in commercial quantities in anambra. Paleoecology of enugu and mamu formations in anambra basin. Subsistence of the anambra plate due to folding and uplift of the abakalikibenue fold belt in the santonian stage produces the anambra basin. 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. Due to geographicpositioning,the lowertroughhasinrecenttimes be describedasthe anambra basin due to stratigraphicsimilarities. Cretaceous sedimentation and paleogeography of the central benue. Palynologiacal and paleoenvironmental investigation of the. Ladipo ko 1988 paleogeography, sedimentation and tectonics of the. 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. 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. Ladtpo department of geology and mlnera sciences university of llorln p. Onuoha department of geology, university of nigeria, nsukka, enugu state, nigeria. Geology and foraminifera analysis of ikem shale and its environs.
The basin developed due to the santonian tectonic event which greatly. Introduction this study examines part of the sedimentary units of the eocene nanka formation of anambra basin exposed at lat. The study area lies within latitudes 50155 55n and longitudes 70156055e, in the anambra basin. Anambra basin has about 6,000 m of sedimentary rocks. Gravity studies in the bida basin put the maximum thickness of the sedimentary successions at about 3. Paleogeography, sedimentation and tectonics of the upper.
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