Petroleum potentials of the nigerian benue trough and anambra. The main oil source formations of the anambra basin, southeastern nigeria. Anambra basin has about 6,000 m of sedimentary rocks. Department of geology, michael okpara university of agriculture, umudike, abia state, nigeria. The oldest sediment in the anambra basin is nkporo group nwajide, 1990.
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. The oldest sedimentary formation in the anambra basin. Sedimentology and geochemical evaluation of campanomaastrichtian sediments, anambra basin, nigeria. 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. Earlier work began with the investigation of tectonism in the southern nigeria. Biostratigraphy and paleoenvironment of the coniacian. Table of contents introduction location ofthe basin geology of the basin tectonichistory petroleum potentialof the basin conclusion a basinisa depressiononthe earthssurface relative tosurroundings.
Obi department of geology, anambra state university, uli, nigeria abstract integration of sedimentologic and sequence stratigraphic interpretations of the. The basin is bounded to the south by the niger delta basin hinge line. 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. 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. It extends northwestward into the niger valley, northward to the jos massif and northeastward into lafia. Matriculation number 142332, of the department of geology, faculty of science, university of. 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. Sedimentology and sequence stratigraphy of the nkporo group. The petroleum geology, biostratigraphy and paleoenvironmental description of anambra basin have been carried out by many authors. 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. 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. Subsurface evaluation of source rock and hydrocarbon potential of the anambra basin, south eastern nigeria iheanacho princewill ugochukwu dissertation.
It consists predominantly of a gently undulating plain with an average elevation varying from 250 to 400 m above sealevel. The geology of nigeria is made up of three major lithopetrological components, namely, the basement complex. Several workers have studied the anambra basin and niger delta in terms of sedimentology. Maastrichtian deposits of ogbabu1 well anambra basin, south eastern nigeria. The basin fill is made up of three formations, namely from the oldest to the youngest, akata, agbada and benin formations 6, 12, 14. Department of geology, anambra state university, uli. The deposits are characterized by a series of mega units referred to as depobelts which strike nwse and subparallel to the present day shoreline. 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 relationship and grain size distribution morphologic studies. Anambra basin sedimentary basin sedimentary rock free.
The study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka formation. Petroleum potentials of the nigerian benue trough and. A revised stratigraphy of the bida basin, nigeria sciencedirect. The basin was initiated during the late cretaceous and covers an area of about 40,000 km 2. This study attempts to reevaluate the discrepancies in past investigations based on the prospective value and. Anambra basin is one of the basins in nigeria, habouring the largest deposit of. The main oil source formations of the anambra basin. Anambra basin is one of the basins in nigeria, habouring the largest deposit of subbituminous coal and lignite. Deltaic sedimentation in the anambra basin was controlled by the morphologic proximity of sediment sources, sea movements during the campanian to eocene times, and. Index map of niger delta and offshore nigeria showing the anambra basin and abakaliki fold belt after doust and omatsola, 1989. A regional evaluation of the paleodepositional environment of. 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 deposits in the benue trough were displaced westwards at this time, causing subsidence of the anambra basin. The shale unit in the mamu formation is the major source rock. 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. 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. Subsurface evaluation of source rock and hydrocarbon. The anambra basin is a roughly triangular basin containing more than 5 km thick of sediments of varied lithologies. Evidence from field relationship and sedimentological study. 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. Pdf geology and depositional environment of campano. Basin wide stratigraphic correlation across the anambra basin using base of the mamu formation as a datum. After the installation of the anambra basin following the. Niger delta province, nigeria, cameroon, and equatorial guinea, africa by michele l.
The akata formation is composed of continuous shale and about 10% sandstone. Oil seepages have also been reported from parts of the basin. Biostratigraphy and paleoenvironment of the coniacian awgu. Geology and mineral resources of the lower benue trough.
Agagu and ekweozor 1982 shows that the awgu and nkporo shales constitute the main source and seal rocks in the anambra basin. The study area is located in the southern part of the anambra basin fig. Based mainly on faunal content, a maastrichtian to paleocene age is given to this formation 11 21. Geology and depositional environment of campanomaastrichtian. Deltaic sedimentation in the anambra basin was controlled by. 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. Depositional environment of siliciclastic deposits on the. This sedimentary phase was initiated by the santonian folding and uplift of the abakaliki anticlinorium along the ne. 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.
This study aimed at determining the geology and depositional environmental of these formations through field. Aromatic hydrocarbon distribution and calculation of oil. The northsouth trending awkaorlu cuesta divides the study area into two relief features, viz. Lithofacies, palynology and paleoenvironmental study of. 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 extends northward to the lower benue river and also forms a boundary with the tertiary.
Aug 28, 2017 sedimentology and geochemical evaluation of campanomaastrichtian sediments, anambra basin, nigeria. The subsurface geology of the niger delta basin to which the asaba capital territory belongs is well established, figure 1. A study of hydrocarbon generation and expulsion of the. The benue trough was formed by rifting of the central west african basement, beginning at the start of the cretaceous period.
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. Aspects of the geology and groundwater conditions of asaba. Anambra basin is one of the energyrich inland sedimentary basins in nigeria. The stratigraphic succession of each region was established and correlated across the basin and to the adjoining anambra basin. Anambra river1, ihadagu1 and very scanty 2d seismic information, anambra basin is under explored. 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. The iullemmeden basin in northwestern nigeria is known locally as the sokoto basin. The mineral resources so far reported in the trough by the geological survey of nigeria agency are discussed below.
Aromatic hydrocarbon distribution and calculation of oil and. Geologic map of southeastern nigeria showing the study area modified from hoque, 1977. Of the anambra basin, nigeria chukwuemeka frank odumodu department of geology, anambra state university, p. Paleoecology of enugu and mamu formations in anambra. 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. Sedimentology and sequence stratigraphy of the nkporo. 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. Paleoecology of enugu and mamu formations in anambra basin.
The marginalshallow marine nkporo group is the basal lithostratigraphic unit of the late campanianmaastrichtian successions of the anambra basin, nigeria fig. Russ 1930, adeleye 1974, whiteman 1982, braide 1992, idowu and enu 1992, akande et al. 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. During the santonian age, around 84 million years ago, the basin underwent intense compression and folding, forming over 100 anticlines and synclines. The anambra basin is situated at the southwestern extremity of the benue trough. The sokoto basin nigerian sector of the iullemmeden basin. It consists predominantly of a gently undulating plain with an. The southern benue trough and anambra basin, southeastern nigeria.
The main geologic units of the study area are the nanka sand ecocene, overlain by ogwashiasaba, formation oligocene and underlain by imo. Hydrogeophysical investigation of southern anambra basin. Earth sciences basins geology analysis cretaceous period estuaries geomorphology sediments geology. Department of geology, federal university, oyeekiti, ekiti state, nigeria. The main oil source formations of the anambra basin, southeastern. Geologic setting and stratigraphy the geology of the anambra basin has been well studied and documented. With less than 50 wells so far drilled two discoveries. Location of the study area geology of anambra and niger delta basin. Palynofacies studies of sedimentary succession in ogbabu1. Pdf petroleum potentials of the nigerian benue trough. Geochemical evaluation of okaba odagbo coal deposit. Geology and mineral resources of the lower benue trough, nigeria. This study is a contribution to our understanding of the hydrocarbon potentials of the nkporo shale in the anambra basin, nigeria. Geology and depositional environment of campanomaastrichtian sediments in the anambra basin, southeastern nigeria.
Pdf the study area lies within the anambra basin and it is made up of enugu shale, mamu formation, ajali sandstone, and nsukka. Therefore, the npkoro shale, as it named by, is partially equivalent to the araromi formation. 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. 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.
Geological survey editorial standards or with the north american stratigraphic. 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. Sedimentology and geochemical evaluation of campano. The stratigraphic sequence in the anambra basin is well discussed in several literatures 28, 1, 26. The geologic formations encountered in the basins include. It was deposited into the basin in late campanian, comprising nkporo shale, owelli sandstone and enugu shale reyment, 1965 and obi, 2001. Evidence from field relationship and sedimentological study adeigbe, o. Anambra basin was then filled with transgressiveregressive cycles between, in the tertiary. 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. A regional evaluation of the paleodepositional environment. The anambra basin is situated west of the lower benue trough and is often considered youngest formation of the benue trough.