Basin wide stratigraphic correlation across the anambra basin using base of the mamu formation as a datum. This study aimed at determining the geology and depositional environmental of these formations through field relationship and grain size distribution morphologic studies. The mineral resources so far reported in the trough by the geological survey of nigeria agency are discussed below. The benue trough was formed by rifting of the central west african basement, beginning at the start of the cretaceous period. Anambra basin is one of the basins in nigeria, habouring the largest deposit of subbituminous coal and lignite. Anambra river1, ihadagu1 and very scanty 2d seismic information, anambra basin is under explored.
Therefore, the npkoro shale, as it named by, is partially equivalent to the araromi formation. The petroleum geology, biostratigraphy and paleoenvironmental description of anambra basin have been carried out by many authors. Paleoecology of enugu and mamu formations in anambra basin. A regional evaluation of the paleodepositional environment of. It consists predominantly of a gently undulating plain with an. Apr 30, 2009 the iullemmeden basin in northwestern nigeria is known locally as the sokoto basin.
This study aimed at determining the geology and depositional environmental of these formations through field. The anambra basin is a cretaceoustertiary basin, which is the structural link between the cretaceous benue trough and the tertiary niger delta basin lucas and ishiekwene, 2010. The study area is located in the southern part of the anambra basin fig. The main oil source formations of the anambra basin. Anambra basin in the lower benue trough is a major coal producing basin in nigeria where intensive exploration and exploitation activities have been on since 1916 owing to the discovery of commercial coal in udi. Sedimentology and sequence stratigraphy of the nkporo group. Of the anambra basin, nigeria chukwuemeka frank odumodu department of geology, anambra state university, p. It extends northward to the lower benue river and also forms a boundary with the tertiary. The study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation. Agagu and ekweozor 1982 shows that the awgu and nkporo shales constitute the main source and seal rocks in the anambra basin. The anambra basin is a roughly triangular basin containing more than 5 km thick of sediments of varied lithologies.
The subsurface geology of the niger delta basin to which the asaba capital territory belongs is well established, figure 1. Anambra basin was then filled with transgressiveregressive cycles between, in the tertiary. The geology of nigeria is made up of three major lithopetrological components, namely, the basement complex. The deposits are characterized by a series of mega units referred to as depobelts which strike nwse and subparallel to the present day shoreline. This sedimentary phase was initiated by the santonian folding and uplift of the abakaliki anticlinorium along the ne. The anambra basin is located in the southwestern end of the benue trough figure 1 and contains up to 9 km of siliciclastic sedimentary strata whiteman, 1982. Aromatic hydrocarbon distribution and calculation of oil. This study was undertaken to study the hydrogeophysical properties of the geologic formations that underlie the southern anambra basin and to help in delineating sites for drilling of productive boreholes in the area. The deposits in the benue trough were displaced westwards at this time, causing subsidence of the anambra basin. Aspects of the geology and groundwater conditions of asaba.
Hydrogeophysical investigation of southern anambra basin. The shale unit in the mamu formation is the major source rock. The main oil source formations of the anambra basin, southeastern nigeria. The stratigraphic succession of each region was established and correlated across the basin and to the adjoining anambra basin. The anambra basin is situated at the southwestern extremity of the benue trough. The iullemmeden basin in northwestern nigeria is known locally as the sokoto basin. The basin is bounded to the south by the niger delta basin hinge line.
Geological survey editorial standards or with the north american stratigraphic. Oil seepages have also been reported from parts of the basin. Location of the study area geology of anambra and niger delta basin. During the santonian age, around 84 million years ago, the basin underwent intense compression and folding, forming over 100 anticlines and synclines. With less than 50 wells so far drilled two discoveries. The basement rocks are also exposed in the north central, southwestern and eastern part of the country and the basement complex are separated by sedimentary rocks except in the north central where they are interwoven for descriptive purposes. The oldest sedimentary formation in the anambra basin. Based mainly on faunal content, a maastrichtian to paleocene age is given to this formation 11 21. Obi department of geology, anambra state university, uli, nigeria abstract integration of sedimentologic and sequence stratigraphic interpretations of the nkporo group has provided the basis for a basin wide framework for prediction of potential. Russ 1930, adeleye 1974, whiteman 1982, braide 1992, idowu and enu 1992, akande et al. Department of geology, anambra state university, uli. Petroleum potentials of the nigerian benue trough and. The basin fill is made up of three formations, namely from the oldest to the youngest, akata, agbada and benin formations 6, 12, 14. Pdf petroleum potentials of the nigerian benue trough.
The anambra basin is situated west of the lower benue trough and is often considered youngest formation of the benue trough. The asu river group in the lower benue trough comprises the shales, limestones, and sandstone lenses of the abakaliki formation in the abakaliki area and the. Geology and mineral resources of the lower benue trough, nigeria. Deltaic sedimentation in the anambra basin was controlled by. Petroleum potentials of the nigerian benue trough and anambra. The main oil source formations of the anambra basin, southeastern. The southern benue trough and anambra basin, southeastern nigeria. Anambra basin is one of the basins in nigeria, habouring the largest deposit of. Index map of niger delta and offshore nigeria showing the anambra basin and abakaliki fold belt after doust and omatsola, 1989. Geology department, federal university of technology, minna, nigeria abstract geochemical studies have been carried out on coal samples from okaba odagbo in the anambra basin of nigeria to determine their geochemical characteristics and possible use as coking coal or otherwise. Matriculation number 142332, of the department of geology, faculty of science, university of. Palynofacies studies of sedimentary succession in ogbabu1. The stratigraphic sequence in the anambra basin is well discussed in several literatures 28, 1, 26.
Aromatic hydrocarbon distribution and calculation of oil and. After the installation of the anambra basin following the. The oban masif, southwestern nigeria basement craton and the cameroon basement complex also served as sources for the sediments of the anambra basin hoque and ezepue, 1977. Earlier work began with the investigation of tectonism in the southern nigeria. Obi department of geology, anambra state university, uli, nigeria abstract integration of sedimentologic and sequence stratigraphic interpretations of the. Anambra basin is one of the energyrich inland sedimentary basins in nigeria 153 it is a nearly triangular shaped embayment covering about 3000 km 2 with a total sedimentary thickness of approximately 9 km 2. Geochemical evaluation of okaba odagbo coal deposit. Biostratigraphy and paleoenvironment of the coniacian awgu. Sedimentology and sequence stratigraphy of the nkporo group campanianmaastrichtian, anambra basin, nigeria shirley o. Subsurface evaluation of source rock and hydrocarbon potential of the anambra basin, south eastern nigeria iheanacho princewill ugochukwu dissertation. Biostratigraphy and paleoenvironment of the coniacian.
The marginalshallow marine nkporo group is the basal lithostratigraphic unit of the late campanianmaastrichtian successions of the anambra basin, nigeria fig. Evidence from field relationship and sedimentological study. Paleoecology of enugu and mamu formations in anambra. Geology and depositional environment of campanomaastrichtian sediments in the anambra basin, southeastern nigeria. Evidence from field relationship and sedimentological study adeigbe, o. It consists predominantly of a gently undulating plain with an average elevation varying from 250 to 400 m above sealevel. Table of contents introduction location ofthe basin geology of the basin tectonichistory petroleum potentialof the basin conclusion a basinisa depressiononthe earthssurface relative tosurroundings. The geologic formations encountered in the basins include. Aug 28, 2017 sedimentology and geochemical evaluation of campanomaastrichtian sediments, anambra basin, nigeria. The main geologic units of the study area are the nanka sand ecocene, overlain by ogwashiasaba, formation oligocene and underlain by imo. A revised stratigraphy of the bida basin, nigeria sciencedirect. Department of geology, federal university, oyeekiti, ekiti state, nigeria. Lithofacies, palynology and paleoenvironmental study of. This study attempts to reevaluate the discrepancies in past investigations based on the prospective value and.
This represents the average thickness of the sedimentary formation that overlay the basement complex within the lower portion of benue basin and the upper portion of anambra basin. Depositional environment of siliciclastic deposits on the. It extends northwestward into the niger valley, northward to the jos massif and northeastward into lafia. 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.
Niger delta province, nigeria, cameroon, and equatorial guinea, africa by michele l. Besides the differences in interpretation, the singleoutcrop approach adopted in the stratigraphic analysis of the nkporo group presented by nwajide and reijers 1996 did not permit determination of largescale stratigraphic distribution. The oldest sediment in the anambra basin is nkporo group nwajide, 1990. The sokoto basin nigerian sector of the iullemmeden basin. The study area is a significant part of anambra river basin stratigraphy and is basically, a result of the paleohydrogy of the region durham et al, 2008. The study area lies within the anambra basin in southeastern nigeria, between longitudes 630 e and 800 e and latitudes 520n and 750 n fig. Deltaic sedimentation in the anambra basin was controlled by the morphologic proximity of sediment sources, sea movements during the campanian to eocene times, and. Several workers have studied the anambra basin and niger delta in terms of sedimentology. Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka. Sedimentology and geochemical evaluation of campano. Sedimentation in the lower benue trough commenced with the marine albian asu river group, although some pyroclastics of aptianearly albian ages have been sparingly reported. Subsurface evaluation of source rock and hydrocarbon. The basement rocks are also exposed in the north central, southwestern and eastern part of the country and the basement complex are separated by sedimentary rocks except in the north central where they are interwoven for. The main objective was to simulate the hydrocarbon generation and expulsion in the nkporo source horizons encountered in igbariam1, iji1, and ajire1 wells drilled in the basin, using the onedimensional genesis zetaware basin modeling software.
It was deposited into the basin in late campanian, comprising nkporo shale, owelli sandstone and enugu shale reyment, 1965 and obi, 2001. Maastrichtian deposits of ogbabu1 well anambra basin, south eastern nigeria. This study is a contribution to our understanding of the hydrocarbon potentials of the nkporo shale in the anambra basin, nigeria. 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. Geology and depositional environment of campanomaastrichtian. Anambra basin sedimentary basin sedimentary rock free. A study of hydrocarbon generation and expulsion of the. Sedimentology and geochemical evaluation of campanomaastrichtian sediments, anambra basin, nigeria. The deepest parts of the basins are the lower southern edge, these are around idah, angba, and ankpa and the midportion of the study area, below udegi, which record. Pdf geology and depositional environment of campano.
Geologic setting and stratigraphy the geology of the anambra basin has been well studied and documented. Obi department of geology, anambra state university, uli, nigeria abstract integration of sedimentologic and sequence stratigraphic interpretations of the nkporo group has provided the basis for a basinwide framework for prediction of potential. Anambra basin is one of the energyrich inland sedimentary basins in nigeria. Geologic map of southeastern nigeria showing the study area modified from hoque, 1977. 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. Anambra basin has about 6,000 m of sedimentary rocks. The tectonic, stratigraphic and organic geochemical evaluations of these basins suggest the similarity with the contiguous basins of chad and niger republics and sudan, where commercial oil discovery have been made. The northsouth trending awkaorlu cuesta divides the study area into two relief features, viz. Earth sciences basins geology analysis cretaceous period estuaries geomorphology sediments geology. Sedimentology and sequence stratigraphy of the nkporo. A regional evaluation of the paleodepositional environment.
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