Aeromagnetic interpretation of basement structure and architecture of the Dahomey Basin, Southwestern Nigeria

10 representative samples of limestone were collected from the Arimogija-Okeluse Axis of the Dahomey Basin and subjected to X-Ray Fluorescence analysis. Major and Trace elements were used to classify and predict the depositional environment of Arimogija-Okeluse limestone.The results for the major oxide composition revealed that CaO content ranges from 47.6-52.31% with a mean value of 50.06%. SiO2concentration varies from 1.94-5.24% with an average of 3.36%. Fe2O3. MgO, and Al2O3contents have mean values of 1.702%, 1.52%, and 1.09% respectively. Other oxides; Na2O, P2O5, K2O and TiO2are low in concentration. The Loss on Ignition also varies from 38.9-41.8 with a mean value of 40.43% suggesting a high carbonate content for the limestone. Standard Ca/Mg and Mg/Ca ratios varies from 25.87-37.63 and 0.03-0.04 with a mean of 33.31and 0.031 respectively. The high strontium content reveals a high saline environmental condition of formation for the limestone.The results obtained, however showed that the Arimogija-Okeluse limestone is a Magnesian limestone type deposited in a shallow marine environment and suitable for cement production.

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Petrography, compositional characteristics and stable isotope geochemistry of the Ewekoro formation from Ibese Corehole, eastern Dahomey basin, southwestern Nigeria

Global Journal of Geological Sciences ◽

10.4314/gjgs.v13i1.5 ◽

2015 ◽

Vol 13 (1) ◽

pp. 35

Author(s):

ME Nton ◽

MO Adeyemi

Keyword(s):

Stable Isotope ◽

Isotope Geochemistry ◽

Stable Isotope Geochemistry ◽

Southwestern Nigeria ◽

Dahomey Basin

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Sedimentation, depositional environments, and hydrocarbon potential of the Maastrichtian-Paleocene Araromi Formation, eastern Dahomey (Benin) Basin, southwestern Nigeria

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01262-7 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3917-3934

Author(s):

Oladotun Afolabi Oluwajana ◽

Abraham Olatunji Opatola ◽

Olajide Jonathan Adamolekun ◽

Otobong Sunday Ndukwe ◽

Gabriel Toluwalope Olawuyi ◽

...

Keyword(s):

Liquid Hydrocarbon ◽

Poor Quality ◽

Depositional Environments ◽

Source Rocks ◽

Coarse Grained ◽

Southwestern Nigeria ◽

Palynological Assemblages ◽

Dahomey Basin ◽

Integrated Study ◽

Hydrocarbon Generating Potential

AbstractThe Cretaceous sediments in southwestern Nigeria are host to one of the largest bitumen deposits in the world. In the current paper, an integrated study on sedimentology, palynology, and applied petroleum geochemistry of the Maastrichtian-Paleocene Araromi Formation was used to determine the depositional environments and hydrocarbon potentials of the formation on the eastern Dahomey Basin. Four sedimentary lithofacies were identified from core samples, namely, lower limestone (F1); medium to coarse-grained sandstone (F2); lower loosely consolidated sandstone (F3); and shale and siltstone (F4). Sedimentation in the eastern Dahomey Basin occurred mainly in fluvial and shallow-marine (shelf) environments. The palynological assemblages of the Araromi Formation reflect deposition in coastal through brackish water to shallow shelf environment with periods of localized wind-induced storms. The shale and siltstone samples of the Araromi Formation are characterized by total organic carbon (TOC) values of up to 2.50 wt % and S2 (hydrocarbon-generating potential) values ranging from 0.26 to 0.70 mgHC/g rock, indicating poor source rocks. Shales show poor quality and thermally immature organic matter at shallow depth and could neither have generated liquid hydrocarbon nor contributed to the heavy oil occurrence on the bitumen and tar-sand belt of eastern Dahomey (Benin) Basin.

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Groundwater Quality Index as a Hydrochemical Tool for Monitoring Saltwater Intrusion into Coastal Freshwater Aquifer of Eastern Dahomey Basin, Southwestern Nigeria

Groundwater for Sustainable Development ◽

10.1016/j.gsd.2021.100568 ◽

2021 ◽

pp. 100568

Author(s):

Jamiu A. Aladejana ◽

Robert M. Kalin ◽

Philippe Sentenac ◽

Ibrahim Hassan

Keyword(s):

Groundwater Quality ◽

Saltwater Intrusion ◽

Quality Index ◽

Southwestern Nigeria ◽

Groundwater Quality Index ◽

Dahomey Basin

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Petrographic Analysis of the Palaeocene-Eocene Phosphate-Bearing Rocks of Eastern Dahomey Basin, Southwestern Nigeria.

10.21203/rs.3.rs-88244/v1 ◽

2020 ◽

Author(s):

Timileyin Olanipekun ◽

Anthony Bolarinwa

Keyword(s):

Plant Growth ◽

Phosphorus Pentoxide ◽

Petrographic Analysis ◽

Mineral Component ◽

Industrial Products ◽

Southwestern Nigeria ◽

Phosphate Mineral ◽

Dahomey Basin ◽

Bone Fragments ◽

Essential Function

Abstract Phosphorus is ubiquitous for its essential function in plant growth. Phosphate-bearing rocks include phosphorites and rocks that host phosphate mineral. Phosphorites, rocks containing ≥18 % phosphorus-pentoxide (P2O5), are essential sources of phosphorus. Due to the vast application of phosphorites in the manufacture of fertilisers and industrial products, the study of phosphate bearing rocks is crucial. This article examines the mineral component and structure of phosphate-bearing rocks in the Eastern Dahomey Basin, Southwestern Nigeria. Eleven pulverised samples of phosphatic rocks were analysed, employing a microscope, for petrographic studies. Three major types of phosphorites exist in the Eastern Dahomey Basin: Granular (which are composed of oolitic and pelletal structures), Nodular (which comprises cylindrical, rectangular, ellipsoidal shapes), and the vesicular (which either have coarse or fine forms) varieties. The phosphorites contain fluorapatite (as the dominant mineral), calcite, quartz, and glauconite. Generally, the phosphorites are fossiliferous (lamellibranches, echinoderms, shell, and bone fragments are observable). The phosphatic limestones are micrite (allochems) hosting collophane (specks of fine-textured fluorapatite) and glauconite. While fluorapatite occurs in the phosphatic claystone, it is glauconitic, just as the gypsum. The results of the petrographic analysis indicated the influence of seawater in the deposition of the phosphate-bearing rocks in an oxic environment.

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Structural Interpretation and Depth Estimation from Aeromagnetic Data of Abigi-Ijebu-Waterside area of Eastern Dahomey Basin, Southwestern Nigeria

Geofísica Internacional ◽

10.22201/igeof.00167169p.2019.58.4.2057 ◽

2019 ◽

Vol 58 (4) ◽

pp. 259-277

Author(s):

Osinowo Olawale Olakunle ◽

Adabanija Moruffdeen A. ◽

Adewoye Oluwatoyin Adebayo

Keyword(s):

Depth Estimation ◽

Aeromagnetic Data ◽

Southwestern Nigeria ◽

Structural Interpretation ◽

Dahomey Basin ◽

Para Determinar

Los datos de alta resolución aeronáutica (HRAM) de la costa de Abigi-Ijebu en la parte oriental de la cuenca Dahomey en el sudoeste de Nigeria se filtraron, transformaron, mejoraron, analizaron e interpretaron en términos de estructuras, geometría del basamento y espesor sedimentario, para evaluar el potencial de prospección petrolera de este sector de la cuenca Dahomey, así como proporcionar información relevante que podría apoyar la campaña de exploración de hidrocarburos del descuidado brazo oriental de la cuenca Dahomey, que recientemente ha demostrado ser prolífico con el descubrimiento de yacimientos de petróleo Aje y Ogo en la parte costera de la cuenca . Los datos de HRAM se filtraron para eliminar el ruido cultural y de fondo, continuaron hacia arriba para suprimir los efectos de fuentes poco profundas y mejorar el efecto de roca del sótano que emana de fuentes relativamente más profundas. Los datos también se redujeron al polo a baja latitud para simplificar las anomalías magnéticas y para enfocar los picos de las anomalías positivamente simétricas con respecto a las fuentes geológicas correspondientes. Se aplicaron filtros derivados para detectar y mejorar las firmas magnéticas alineadas de forma preferencial que reflejan el marco estructural del área de estudio. El análisis espectral radial y las técnicas de ponderación de profundidad de Euler se emplearon para determinar la profundidad de las fuentes magnéticas que generaron la topografía del basamento y, por lo tanto, el espesor de las rocas sedimentarias que cubren las rocas cristalinas. Los derivados y filtros derivados de inclinación mejoraron y delinearon varias estructuras regionales lineales, algunas de las cuales tienen más de 15 km de longitud y una tendencia principalmente a lo largo de la dirección NE - SW. El análisis espectral y las soluciones de ponderación de profundidad de deconvolución de Euler 3D indican que la profundidad en la parte superior de las anomalías magnéticas varía desde alrededor de 100 m por encima del dato de referencia de Minna hasta más de 2,0 km por debajo del dato. La topografía del basamento revelada por las parcelas de solución de Euler indica rocas del basamento de la corteza gradual y suavemente deprimidas que pueden ser ayudadas por fallas regionales que gradualmente descendieron o deprimieron las rocas de la corteza hacia el sur para aumentar el acomodo de los sedimentos. Por lo tanto, esto sugiere un aumento en el potencial de prospección de hidrocarburos hacia el sur del área de estudio, especialmente en el mar abierto y más profundamente en el Océano Atlántico.

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