Browsing by Author "Nton, M.E"

Now showing 1 - 3 of 3

" Compositional characteristics and industrial assessment of sedimentary clay bodies in part of eastern Dahomey Basin, southwestern Nigeria "
(Nigerian mining and geosciences society, 2005) Nton, M.E; Elueze, A.A.
"Clay bodies occur as lenses and interbeds within the predominantly shaley Akinbo Formation in the eastern Dahomey Basin. They are greenish to grayish, plastic, and in some places contain concretions. In order to assess their sedimentological significance as well as evaluate their potential as industrial raw materials, representative outcrop arid borehole samples .were subjected to mineralogical, chemical and physical characterization. Mineralogical determination by X-ray diffraction (XRD) method, indicates kaolinite as the major clay mineral, with a range of 32.86-58.33%. Other constituents are illite (4.95%), smectite (2.87-14.29%) and palygorskite (2.87%). The non-clay minerals are quartz, K-feldspar, micas and graphite. In terms of chemical composition, the clay bodies. are characterised by the following; Si02 (52.96-55.84%), Al2O3 (16.22-17.74%) Fe203 (7.13-10.35%); CaO (4.65-7.95%)-; MgO (2.26-3.98%) while Na20, K2O, MnO, Ti02 and P2Os have individual values < 1%. The relatively high CaO reflect some contribution from the limestone bed underlying this formation. The clay specimens generally display colour ranging from grayish in fresh, to brownish-red on firing. Corresponding values of physical parameters include linear shrinkage (3.75-7.50%), plastic limit (23- 31%), liquid limit (48-56%), plasticity index (21-30%) and water absorption capacity (5.80-11.90%). The average silica sesquioxide and alumina-iron oxide ratios are respectively 2.17 and 2.08. These values are within the range suitable for clays or shales to be used in the manufacture of good quality cement. The clays have high silica content and are relatively rich in fluxing elements such as Ca and Mg, and could be utilized in the manufacture of domestic and sanitary earth wares. The high plasticity as reflected by the values of the relevant physical indices, and the general fineness qualify the clays to be useful as fillers or coating materials in paper and paint industries. They could also be useful in the production of construction bricks, ceramics, and with beneficiation, the quality might improve for other applications. "
Patrography and compositional characteristics of Ewekoro formation, eastern Dahomey basin, southwestern Nigeria: implications for depositional environment and reservoir characteristics
(Nigerian association of petroleum explorists, 2013) Nton, M.E; Adeyemi, M.O.
Subsurface samples of the predominantly carbonate Ewekoro foundation, obtained from the Ibese core hole, in the eastern Dahomey Basin, were examined based on petrographic and geochemistry indices. The study aims at ascertaining the microfacies, depositional environment, as well as the reservoir characteristics. Petrographic reveals sandy biomicrite, biomicrite, biosparite and dolomitic microfacies with fossil content made up of gastropods, brachiopods, ostracods, coralline algae and foraminifera. It is observed that the depositional porosity has been altered by different diagenetic pore types which could serve as conduits for fluids. Major element oxides ranges; CaO (39.79-53.98wt. %), SiO2 (1.29-25.37 wt. %), AI2O3 (0.43-3.77 wt. %) K2O (0.04-0.27wt. %)Fe2O3 (0.74-2.35wt. %), and Na2O (<0.01-0.05 wt. %). Correlation coefficient shows that elements such as Na, K, Ti, Ba, Cs, Ga, Rb, Sr, Th, La, Ce, Mo, and Ni have strongly correlated values with Al (r >0.75). Consequently, they share siliciclastic origin with abundance of Al and their fluctuations can be linked to variation in detrital influx. The U/Th ratio (-0.25 to 2.3) and the V/Sc ratio (-6.0 to 23) suggest that the Ewekoro limestone was deposited in an oxic to anoxic setting with a strong anoxic influence.
Sedimentology and depositional environment of Awi formation Calabar flank, southeastern Nigeria
(Journal of mining and geology, 1999) Nton, M.E
"A sequence of conglomerates, sandstones, siltstones, claystones carbonaceous shales and mudstones which rims the Oban Massif in the Calabar Flank, constitutes the Early Cretaceous (probably Aptian) Awi Formation In the southeastern Nigeria. Field studies and laboratory analyses were conducted on these sediments to determine their provenance and depositlonal environment. Field observations show that the sediments are grently dipping (.< 16°) in a southwesterly direction. They vary in thickness from thin to very thick beds and are laterally, discontinuous. The pattern of sedimentation is cyclic with fining upward sequences. The sediments are textually immature with angular to subangular grains dominating, thus indicating short distance transportation. The sandstones are medium to coarse-grained, poorly sorted, mostly leptokurtic, fine skewed and unimodal in distribution. They are subarkoslc with more than 70% quartz which are of Igneous and metamorphic origin while the associated claystones contain kaolinite. Heavy mineral assemblages show the presence of predominantly zircon, tourmaline, rutile, garnet and staurolite with a range of 66.7 to 96%. This indicates mature to superrnature sandstones and can be attributed to wet climatic conditions. The carbonaceous shales which grade into mudstone In some cases are non-fossillferous, poorly laminated, pyritized and rich in lignitised wood. All these indicate that sediments of Awi Formation were derived from the Oban Massif and deposited in environments ranging from channel lag and point bar to flood plain. "