scholarly journals New Oligocene to Early Miocene Palynomorph Zonation of GZ-1 Well, Onshore Western Niger Delta, Nigeria

2021 ◽  
Vol 25 (4) ◽  
pp. 511-521
Author(s):  
F.O. Amiewalan ◽  
F.O. Balogun
Keyword(s):  
Niger Delta ◽  
Pollen Grain ◽  
Early Miocene ◽  
Spores And Pollen ◽  
Important Indicator ◽  
Delta Area ◽  
Palynological Analysis ◽  
Indicator Taxa ◽  
Early Oligocene ◽  
Angiosperm Pollen

Palynological studies was carried out on GZ-1 well from the onshore western Niger Delta in order to recognized a new detected developments in the varieties of key pollen and spore taxa that have shorter and more distinguished interval zones to advance stratigraphical delineation. Palynological analysis was carried out using the conventional maceration technique for recovering acid insoluble organic-walled microfossils from sediments. The result yielded rich and diversified palynomorphs. The main assemblage were dominated by angiosperm pollen grain (dominant global flora from Late Cretaceous onwards) followed by pteridophytes/bryophyte spore. Dinoflagellate cysts, on the contrast, were less diverse while the Gymnosperm pollen were scarce. The identified palynomorph were used to establish seven main zones - AF1 Psilatricolporites crassus zone, AF2 Verrucatosporites usmensis zone, AF3 Triplochiton scleroxylon zone, AF4 Crassoretitriletes vanraadshooveni zone, AF5 Acrostichum aureum zone, AF6 Gemmatriporites ogwashiensis zone and AF7 Retitricolporites irregularis zone in this study. Established on quantitative events, the zones were also divided into seven subzones with some having finer subdivisions into (a) and (b) ranging in age from Early Oligocene to Early Miocene. Previous unfiled event trends of important indicator taxa of spores and pollen accredited to Pelliceria, Caesalapinoideae, Stenochlaena palustris, Polypodiaceae, Lygodium microphyllum, Polypodiaceae, Adiantaceae and Amanoa (Euphorbiaceae) have assisted improvement of formerly used palynological zonation schemes in the Niger Delta. It is anticipated that this quantitative zonation scheme erected, will help with imminent palynostratigraphical studies in the onshore Niger delta area.

scholarly journals Foraminiferal analysis of AE-1 well, Agbada formation Onshore, Western Niger Delta Basin: Implication for biozonation and age dating

2020 ◽  
Vol 26 (2) ◽  
pp. 107-118
Author(s):  
Florence O. Amiewalan ◽  
Frankie .O. Balogun
Keyword(s):  
Niger Delta ◽  
Age Dating ◽  
Early Miocene ◽  
Total Count ◽  
Early Oligocene ◽  
Sandy Clay ◽  
Sandy Shale ◽  
Shaly Sand ◽  
Stratigraphic Ranges ◽  
Niger Delta Basin

Foraminiferal and sedimentological analysis was carried out using ditch cutting samples from intervals 2700 ft. - 10,185 ft. in AE-1 well. The samples were composited at 60 ft. into ninety four (94) ditch cutting samples. The standard micropaleontological sample procedures to recover the foraminiferal biofacies assemblages was utilized, followed by analysis and interpretation of the obtained results. The sedimentological analysis reveals five lithofacies - sandstone, sandy shale, shaly sand, mudstone and sandy clay which constitute part of the Agbada Formation of the Niger Delta. The foraminiferal fauna recovered from the samples studied comprised of twenty four species grouped into nineteen genera from niniteen families and nineteen subfamilies. A few number of miscellaneous microfossils such as Ostracoda, Holothuroidea and Echinoderm remains were recovered. The total count of foraminiferal defined from this well is four hundred and nineteen (419). The planktic foraminiferal count was two hundred and forty two (242) (57.8 % of the total count) while the benthics foraminiferal count was one hundred and seventy seven (177) (42.2 % of the total count). Among the benthic forms, the calcareous consists of one hundred and forty nine forms (149) (33.4 % of the total benthic count) while the agglutinating benthic forms were thirty seven (37) (8.8 % of the total benthic count). One (1) planktic (Chiloguembelinacubensis) and three (3) benthic (Eponidesberthelotianus, Hanzawaiastratonii and Nonionellaauris) informal foraminiferal zones were established in the well. The age of the AE-1 well sediments has been interpreted to belong to Early Oligocene - Early Miocene in comparism with foraminiferal markers species whose stratigraphic ranges are well established in the Niger Delta and globally. This inferred the presence of the Rupelian - Burdigalian sediments in the Niger Delta. Keywords: Foraminiferal, Biozone, Age, Rupelian, Burdigalian.

scholarly journals Palynostratigraphic and Paleoenvironmental Study of an Offshore Well in the Niger Delta Nigeria

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Dairo VA
Keyword(s):  
Organic Matter ◽  
Niger Delta ◽  
Botryococcus Braunii ◽  
Optical Microscope ◽  
Late Oligocene ◽  
Delta Area ◽  
Early Oligocene ◽  
Pollen And Spores ◽  
Abundance And Diversity ◽  
Sandy Mudstone

Palynomorphs were employed in this study to deduce the palynozones, age and paleoenvironment of an exploratory well drilled in the Niger Delta area. Sixty (60) ditch cutting samples were selected at intervals of 60ft from the depth of 6110ft to 11690ft and subjected to palynological laboratory analysis. The residual samples which comprise of Particulate Organic Matter (POM) were identified under optical microscope and the information from the abundance of pollens and spores identified were imputed into the Stratabug software. The lithostratigraphy of the section penetrated by the well comprises of intercalation of sandy mudstone, argillaceous sandstone to coarse sandstone. Also, a total of one hundred (100) palynomorph species were identified, out of which some marker species such as Botryococcus braunii, Laevigatosporites sp, Striatopollis catatumbus, Stiamoncolpites rectostriatus, Peregrinipollis nigericus, Cicatricosisporites dorogensis, Verrucatosporites sp, and Pachydermites diederixi were identified. This was followed by biozonation with the aid of standard zonation scheme and four (4) zones of pollen and spores comprising of P540, P560, P580 and P5620 were identified based on the Last Downhole Occurrence (Base) and First Downhole Occurrence (Top) of some marker species. Based on the palynozones identified, the age of the sections penetrated by the well ranges from late Oligocene to early Oligocene, which falls within the Rupelian and Chattian stage while the paleoenvironmental studies of the abundance and diversity of pollens and spores with respect to their environment, shows that most of the species falls within the Brackish water and the Freshwater swamps environments.

scholarly journals The Cenozoic Malaguide Basin from Sierra Espuña (Murcia, S Spain): An Example of Geological Heritage

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Santiago Moliner-Aznar ◽  
Manuel Martín-Martín ◽  
Tomás Rodríguez-Estrella ◽  
Gregorio Romero-Sánchez
Keyword(s):  
Middle Eocene ◽  
Geological Heritage ◽  
Passive Margin ◽  
Early Miocene ◽  
Late Oligocene ◽  
Deep Basin ◽  
Sedimentary Evolution ◽  
Early Oligocene ◽  
Upper Oligocene ◽  
Very High

The Cenozoic Malaguide Basin from Sierra Espuña (Internal Betic Zone, S Spain) due to the quality of outcropping, areal representation, and continuity in the sedimentation can be considered a key-basin. In the last 30 years, a large number of studies with very different methodological approaches have been done in the area. Models indicate an evolution from passive margin to wedge-top basin from Late Cretaceous to Early Miocene. Sedimentation changes from limestone platforms with scarce terrigenous inputs, during the Paleocene to Early Oligocene, to the deep basin with huge supplies of turbidite sandstones and conglomerates during the Late Oligocene to Early Miocene. The area now appears structured as an antiformal stack with evidence of synsedimentary tectonics. The Cenozoic tectono-sedimentary basin evolution is related to three phases: (1) flexural tectonics during most of the Paleogene times to create the basin; (2) fault and fold compartmentation of the basin with the creation of structural highs and subsiding areas related to blind-fault-propagation folds, deforming the basin from south to north during Late Oligocene to Early Aquitanian times; (3) thin-skin thrusting tectonics when the basin began to be eroded during the Late Aquitanian-Burdigalian. In recent times some works on the geological heritage of the area have been performed trying to diffuse different geological aspects of the sector to the general public. A review of the studies performed and the revisiting of the area allow proposing different key-outcrops to follow the tectono-sedimentary evolution of the Cenozoic basin from this area. Eight sites of geological interest have been selected (Cretaceous-Cenozoic boundary, Paleocene Mula Fm, Lower Eocene Espuña-Valdelaparra Fms, Middle Eocene Malvariche-Cánovas Fms, Lowermost Oligocene As Fm, Upper Oligocene-Lower Aquitanian Bosque Fm, Upper Oligocene-Aquitanian Río Pliego Fm, Burdigalian El Niño Fm) and an evaluation has been performed to obtain four parameters: the scientific value, the educational and touristic potential, and the degradation risk. The firsts three parameters obtained values above 50 being considered of “high” or “very high” interest (“very high” in most of the cases). The last parameter shows always values below 50 indicating a “moderate” or “low” risk of degradation. The obtained values allow us considering the tectono-sedimentary evolution of this basin worthy of being proposed as a geological heritage.

scholarly journals Late oligocene–early miocene shortening in the Thrace Basin, northern Aegean

2021 ◽  
Author(s):  
Ümitcan Erbil ◽  
Aral I. Okay ◽  
Aynur Hakyemez
Keyword(s):  
Large Scale ◽  
Middle Eocene ◽  
Early Miocene ◽  
Fold Axis ◽  
Late Oligocene ◽  
The Balkans ◽  
Sedimentary Sequences ◽  
The North ◽  
Early Oligocene ◽  
Thrace Basin

AbstractLate Cenozoic was a period of large-scale extension in the Aegean. The extension is mainly recorded in the metamorphic core complexes with little data from the sedimentary sequences. The exception is the Thrace Basin in the northern Aegean, which has a continuous record of Middle Eocene to Oligocene marine sedimentation. In the Thrace Basin, the Late Oligocene–Early Miocene was characterized by north-northwest (N25°W) shortening leading to the termination of sedimentation and formation of large-scale folds. We studied the stratigraphy and structure of one of these folds, the Korudağ anticline. The Korudağ anticline has formed in the uppermost Eocene–Lower Oligocene siliciclastic turbidites with Early Oligocene (31.6 Ma zircon U–Pb age) acidic tuff beds. The turbidites are underlain by a thin sequence of Upper Eocene pelagic limestone. The Korudağ anticline is an east-northeast (N65°E) trending fault-propagation fold, 9 km wide and 22 km long and with a subhorizontal fold axis. It is asymmetric with shallowly-dipping northern and steeply-dipping southern limbs. Its geometry indicates about 1 km of shortening in a N25°W direction. The folded strata are unconformably overlain by Middle Miocene continental sandstones, which constrain the age of folding. The Korudağ anticline and other large folds in the Thrace Basin predate the inception of the North Anatolian Fault (NAF) by at least 12 myr. The Late Oligocene–Early Miocene (28–17 Ma) shortening in the Thrace Basin and elsewhere in the Balkans forms an interlude between two extensional periods, and is probably linked to changes in the subduction dynamics along the Hellenic trench.

scholarly journals Malaria and its burden among pregnant women in parts of the Niger Delta area of Nigeria

2012 ◽  
Vol 1 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Chukwuocha Uchechukwu Madukaku ◽  
Dozie Ikechukwu Nosike ◽  
Chukwuocha Adanna Nneoma
Keyword(s):  
Pregnant Women ◽  
Niger Delta ◽  
Delta Area

Foraminifera Biostratigraphy of Two Wells in Niger Delta

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Dairo VA
Keyword(s):  
Niger Delta ◽  
Middle Miocene ◽  
Early Miocene ◽  
Orbulina Universa ◽  
Exploratory Wells ◽  
Stratigraphic Range

Biostratigraphic studies of foraminifera were carried out on two exploratory wells drilled in the Eastern Niger Delta to establish the age, biozonation and paleoenvironment of the foraminifera present in the strata penetrated by the wells. A total of 80 ditch cutting samples retrieved at 60ft intervals from AX-1 and AX-2 Wells at the depth of 3,600ft to 6,000ft and 4,200ft to 6500ft. respectively were subjected to micropaleontological analysis which involves picking and identification of the foraminifera present. The resulting data were loaded into the Stratabug software and interpreted. The foraminifera recovered and identified from the two wells are made up of both benthic and planktic species. The marker species, whose stratigraphic range are well established were used to describe the biozonation and these includes Heterostegina sp, Catapsydrax stainforthi, Chiloguembelina victoriana, Orbulina universa/suturalis, Praeorbulina sicana,Buliminella subfusiformis, Nonion centrosulcatum, Catapsydrax dissimilis, Globigerinoides bisphericus and Globigerinoides sicanus. Four biozones of foraminifera made up of N8, N7-N8, N6-N7 and N5-N6 were recognised based on the zonation scheme of Grandstein; with their stratigraphic age ranging from early Miocene to middle Miocene. Furthermore, the environment of deposition prevailing in the Formations penetrated by the two wells are predominantly middle neritic with similarity in their ages as observed from the correlation of the biozones from the two wells

scholarly journals The Nossa Senhora da Luz flora from the Early Cretaceous (early Aptian-late Albian) of Juncal in the western Portuguese Basin

2018 ◽  
Vol 58 (2) ◽  
pp. 159-174 ◽  
Author(s):  
Mário Miguel Mendes ◽  
Else Marie Friis
Keyword(s):  
Early Cretaceous ◽  
Pollen Grains ◽  
Fossil Flora ◽  
Spores And Pollen ◽  
Fossil Assemblage ◽  
Seasonally Dry ◽  
Palynological Assemblage ◽  
Conifer Seeds ◽  
Angiosperm Pollen ◽  
The Village

AbstractA new fossil flora is described from the Early Cretaceous of the western Portuguese Basin, based on a combined palynological-mesofossil study. The fossil specimens were extracted from samples collected in the Nossa Senhora da Luz opencast clay pit complex near the village of Juncal in the Estremadura region. The plant-bearing sediments belong to the Famalicão Member of the Figueira da Foz Formation, considered late Aptianearly Albian in age. The palynological assemblage is diverse, including 588 spores and pollen grains assigned to 30 genera and 48 species. The palynoflora is dominated by fern spores and conifer pollen. Angiosperm pollen is also present, but subordinate. The mesofossil flora is less diverse, including 175 specimens ascribed to 17 species, and is dominated by angiosperm fruits and seeds. The mesofossil flora also contains conifer seeds and twigs as well as fossils with selaginellaceous affinity. The fossil assemblage indicates a warm and seasonally dry climate for the Nossa Senhora da Luz flora.

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