Tag Archives: Stratigraphy

Taxonomic Notes on Some Members of Genus Uvigerina from the Deep Offshore Eastern Niger Delta Nigeria (Published)

In an effort to give a systematic taxonomic account of benthic foraminifera from the Niger Delta, a total of 1,213 specimens of foraminifera were retrieved from 85 composite ditch cuttings samples from NEP-1 Well, off-shore eastern Niger Delta Nigeria. A detailed taxonomic appraisal of 140 specimens from the genus Uvigerina was carried out. The interval studied is 1750 meters thick, belonging to the Agbada Formation; lithologically, the section varies from shaly-sand to sandy-shale to shale. A genus of benthic foraminifera –Uvigerina d’Orbigny 1826, comprising of 4 species were identified, and described in details from this site, these includes Uvigerina peregrina Cushman 1923, Uvigerina bifurcata d’Orbigny 1839, Uvigerina hispida Schwager, 1866 and Uvigerina senticosa Cushman 1927.  The fifth species (Uvigerina sp.) is identified to generic level and therefore described in open nomenclature.

Keywords: Assemblages, Diagnosis, Genus, Palaeontology, Stratigraphy

Taxonomic Notes on Some Members of Genus Uvigerina from the Deep Offshore Eastern Niger Delta Nigeria (Published)

In an effort to give a systematic taxonomic account of benthic foraminifera from the Niger Delta, a total of 1,213 specimens of foraminifera were retrieved from 85 composite ditch cuttings samples from NEP-1 Well, off-shore eastern Niger Delta Nigeria. A detailed taxonomic appraisal of 140 specimens from the genus Uvigerina was carried out. The interval studied is 1750 meters thick, belonging to the Agbada Formation; lithologically, the section varies from shaly-sand to sandy-shale to shale. A genus of benthic foraminifera –Uvigerina d’Orbigny 1826, comprising of 4 species were identified, and described in details from this site, these includes Uvigerina peregrina Cushman 1923, Uvigerina bifurcata d’Orbigny 1839, Uvigerina hispida Schwager, 1866 and Uvigerina senticosa Cushman 1927.  The fifth species (Uvigerina sp.) is identified to generic level and therefore described in open nomenclature.

Keywords: Assemblages, Diagnosis, Genus, Palaeontology, Stratigraphy

Geotechnical Evaluation of Foundation Conditions in Igbogene, Bayelsa State, Nigeria (Published)

Geotechnical studies were carried out to investigate the foundation conditions in Igbogene, Etelebou in Bayelsa State, Nigeria. The evaluation was carried out by means of three (3) number boreholes to a maximum depth of 30m below the existing ground level using a using the cable percussive rig. Field and laboratory investigations reveal a near surface stratigraphy of clay to an average depth of 6m underlain by loose silty sand to a depth of 10m below the existing ground level. Underlying this clay layer, the formation presents a stratum of sand which extends to the maximum depth of investigation. Field and laboratory analysis carried out on relatively undisturbed soil samples of the silty clay showed the undrained shear strength of this near surface soil to lie between 40 and 56 kPa with a mean value of 47kPa.  However, the 1.0m thick peat embedded between 3.0m and 4.0m will great increase the compressibility of this clay. Pile foundation is recommended, considering the anticipated load and the very high compressibility of peat under imposed load. Piles should be straight-shaft, closed-ended steel pipe piles and driven into the medium dense sand.  Pile load test should be carried out on all piles to confirm working load and estimated settlements.

Keywords: Bayelsa State, Borehole, Stratigraphy, engineering geology, foundation, subsoil

Palynostratigraphy Analysis of the Agbada Formation (Nep-1 Well) Offshore, Eastern Niger-Delta Basin, Nigeria (Published)

Palynological analyses were carried out using 36 composite ditch cutting samples from NEP -1 well, off-shore eastern Niger Delta Nigeria. The interval studied is 1750 meters thick, belonging to the Agbada Formation; lithologically, the section varies from shaly-sand to sandy-shale to shale. Three zonal assemblage schemes have been erected; zone boundaries were placed where significant changes occurred in the abundance of the species, the proposed palynological zones are: Echiperiporites cf. estelae, Psilatricolpites okeizeis and Foeveotricolpites sp. zones; these are correlatable with the pantropical zones. Samples from the section are assigned a late Miocene to early Pliocene age based on the palynological evidences at this site.

Keywords: Agbada, Niger-Delta, Palynomorph, Palynostratigraphy, Stratigraphy

PALYNOSTRATIGRAPHIC ANALYSIS OF THE AGBADA FORMATION (NEP-1 WELL) OFFSHORE, EASTERN NIGER-DELTA BASIN, NIGERIA (Published)

Palynological analyses were carried out using 36 composite ditch cutting samples from NEP -1 well, off-shore eastern Niger Delta Nigeria. The interval studied is 1750 meters thick, belonging to the Agbada Formation; lithologically, the section varies from shaly-sand to sandy-shale to shale. Three zonal assemblage schemes have been erected; zone boundaries were placed where significant changes occurred in the abundance of the species, the proposed palynological zones are: Echiperiporites cf. estelae, Psilatricolpites okeizeis and Foeveotricolpites sp. zones; these are correlatable with the pantropical zones. Samples from the section are assigned a late Miocene to early Pliocene age based on the palynological evidences at this site.

Keywords: Agbada, Niger-Delta, Palynomorph, Palynostratigraphy, Stratigraphy