scholarly journals Sedimentological and geochemical characterization of DF-2 well, Onshore Western Niger Delta: Implications for provenance, tectonic history and paleo depositional conditions

2020 ◽  
Vol 26 (2) ◽  
pp. 141-155
Author(s):  
Florence O. Amiewalan ◽  
Frankie .O. Balogun ◽  
Kingsley Ejairu

The sedimentology and geochemistry of the major oxides and trace elements of DF-2 well, Onshore, Niger Delta, are presented in this study. The study is aimed at describing the sedimentological characteristics as well as using the major oxides and trace elements to investigate the provenance, tectonic history and palaeo-depositional conditions of the well. Selected samples were investigated with fused bead X-Ray Fluorescence (XRF) spectrometry to determine their major oxides and fused bead laser ablation inductively couple plasma mass spectroscopy (LA-ICP-MS) for  their trace elements. Sedimentological analysis from the well shows that the lithology ranged from shaly sand, sandy shale, sandstone and shale. The results show the dominance of silicon oxide (SiO2) contents which ranges from 81.1 to 91.4 wt. % (average of 87.1 wt. %). The low average concentration of Cr<150 ppm and Ni <100 ppm, the ratios of Th/Sc, Th/Co, Th/Cr, Cr/Th, La/Sc, as well as the plots of Th/Co versus La/Sc and TiO2 versus Zr, all infer a felsic source rock. The discrimination plots of ratioK2O/Na2O against SiO2 and Log K2O/Na2O against Log SiO2/Al2O3 indicated passive continental margin. Various chemical classifications of the sediments show that the sandstone facies plotted mainly in quartzarenite, sublitharenite and Fe-rich sand domains. The samples were deposited under oxic environment based on the average values of U/Th (0.26 ppm), Ni/Co (2.79 ppm) and Cu/Zn (1.81ppm) and bivariate plot of Ni/Co versus V/Cr. However, the bivariate plot of Ni/Co versus V/ (V+Ni) specifies oxic to  anoxic conditions and V/Vi + Ni ratios indicate oxic, suboxic to euxinicpalaeode positional environments for the sediments. Geochemical characterization illustrates mixed marine and terrigenous source input, deposited mainly in semi humid/humid climate. The positive values attained from ratios of Al2O3/(CaO+MgO+Na2O+K2O) infers mineralogical maturity based on stable mobile oxides content in the studied samples. Keywords: Felsic Rock, Quartzarenite, Litharenite, Passive Margin, Mobile Oxide, Mature Sediments.

2020 ◽  
Vol 24 (2) ◽  
pp. 381-391
Author(s):  
F.O. Amiewalan ◽  
F.A. Lucas

Major oxides and trace elements analysis was carried out on ditch cutting samples of FE-1 well, Onshore, Niger Delta Basin, to define their oxygen condition, paleo-climatic conditions, provenance, tectonic setting, sandstone classification and maturity of the sediments. Sedimentological analysis revealed five main lithofacies comprising of sandstone, shaly sand, mudstone, sandy clay and sandy shale. Geochemical results indicates that the average value of silica (87.1 wt. %) is far higher than the average values of the rest oxides which shows the duration and intensity of weathering and destruction of other minerals during transportation. Bivariate plot of La/Sc versus Th/Co, Zr versus TiO2, and trace elemental ratios of Th/Sc, Th/Co, Th/Cr, Cr/Th, La/Sc establishes that the source of the sediment are from felsic rock. Different chemical classification schemes characterized the sediments as quartzarenite, lithic arenites and Fe-rich sand. The plot of Log (K2O/Na2O) versus Log (SiO2/Al2O3) and K2O/Na2O versus SiO2 all plotted mainly in the passive margin zone. The low average value of uranium content, trace elemental ratios of U/Th, Ni/Co, Cu/Zn, V/Cr and binary plot of Ni/Co versus V/Cr indicated an oxic environment of deposition. However, the binary plot of Ni/Co versus V/ (V+Ni) indicates oxic to anoxic condition during deposition of the mixed marine and terrigenous source input sediment. Binary plot of SiO2 versus (Al2O3+Na2O+K2O) designates deposition mainly in humid/semi-humid climatic condition. The samples studied have a much higher SiO2/Al2O3 ratio with low Fe2O3/K2O ratio, thus, they are mineralogically mature. The Al2O3/(CaO+MgO+Na2O+K2O) ratio inferred that there are stable mobile oxides in the samples. Keywords: Major oxides, lithic arenites, provenance, tectonic setting.  


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
S. O. Oni ◽  
A. S. Olatunji ◽  
O. A. Ehinola

Provenance analysis serves to reconstruct the predepositional history of a sediment/sedimentary rock. This paper focuses on the reconstruction of the provenance and tectonic settings of the Niger delta clastic facies using geochemical approach. The main types of geochemical tests include major, trace, and rare earth element (REE) tests. Twenty-one samples of shales and sandstones units were purposely collected from a depth between 1160 and 11,480 m, grinded, pulverized, and sieved with a <75 μm. About 5 g was packed and sent to Acme analytical Laboratory Ltd., Vancouver, Canada. The analyses were carried out by both induced coupled plasma-mass spectrometry (ICP-MS) and induced coupled plasma-emission spectrometry (ICP-ES). Bulk-rock geochemistry of major oxides, trace elements, and rare earth elements was utilized for the provenance and tectonic setting determination. Based on the discrimination diagram for major oxides, the probable provenance of the south eastern Delta clastic sediments was mainly of the active continental margins. The bivariate plots of La versus Th, La/Y versus Sc/Cr, and Ti/Zr versus La/Sc and the trivariate plots of La-Th-Sc, Th-Sc-Zr/10, and Th-Co-Zr/10 are all plotted on the fields of active continental margin sediments which is consistent with the known actively opening of a failed arm of triple junction. The trace elements and REE analysis indicates that they are virtually Fe-rich, lithic/quartz arkosic sandstones. The normalizing factors used for the REE are Wakita chondrite. Their rare earth elements (REE) pattern displays high light REE/heavy REE (LREE/HREE) ratio, flat HREE, and a significant negative Eu anomaly which correlate well with the UCC and PAAS average composition. The source area may have contained felsic igneous rocks.


2020 ◽  
Vol 18 (1) ◽  
pp. 77-96
Author(s):  
Hameed Alsamadany ◽  
Hassan S. Al-Zahrani ◽  
El-Metwally M. Selim ◽  
Mohsen M. El-Sherbiny

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.


2015 ◽  
Vol 45 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Hermínio Arias Nalini Júnior ◽  
Rômulo Machado ◽  
Essaid Bilal

The Urucum suite (582 ± 2 Ma, zircon U-Pb age), situated in the Mid-Rio Doce Valley, eastern part of Minas Gerais State, is characterized by elongated, NW-SE and N-S trending granitic massifs associated with the Conselho Peña-Resplendor high-angle shear zone. It corresponds to a syn to late collisional magmatism that presents dominant solid-state foliation. Four facies are distinguished within the Urucum suite: (i) a porphyritic (Urucum); (ii) a medium- to coarse nequigranular (Palmital); (iii) a tourmaline-bearing; and (iv) a pegmatitic facies. These facies are peraluminous, with alumina saturation index varying from 0.98 to 1.38. SiO2 contents vary from 70.7 to 73.7 wt%, with K2O values ranging from 3.5 to 5.7 wt%, Na2O from 1.9 to 4.4 wt%, MgO from 0.6 to 1.2 wt%, and CaO from 0.3 to 0.9%. Harker-type diagrams show rather continuous trends from the less-evolved Urucum facies to the more evolved tourmaline-bearing and pegmatitic facies. The behavior of several major oxides and trace elements (Fe2O3, MgO, MnO, CaO, TiO2, Al2O3, K2O, Rb and Ba) reflects the role played by fractionation of ferromagnesian minerals, feldspars and accessory minerals. Initial Sr87/Sr86 ratios vary from 0.711 to 0.716, with εNd (580 Ma) values between -7.4 to -8.2, and Sm-Nd TDM model ages ranging from 2290 to 1840 Ma.


2019 ◽  
Author(s):  
Onema C. Adojoh ◽  
◽  
Fabienne Marret-Davies ◽  
Fabienne Marret-Davies ◽  
Robert Duller ◽  
...  

2020 ◽  
Vol 18 (1) ◽  
pp. 443-452
Author(s):  
Grażyna Kowalska ◽  
Urszula Pankiewicz ◽  
Radosław Kowalski ◽  
Artur Mazurek

AbstractThe objective of the study was to determine the content of cadmium (Cd), lead (Pb), arsenic (As), aluminium (Al), thallium (Tl), antimony (Sb) and uranium (U) in the apple and orange juices and black currant nectar in relation to the kind of packaging. Also, probabilistic risk assessment (non-carcinogenic) was estimated by models including target hazard quotient (THQ and THQ*). Aluminium (Al) was present at the highest concentration in the analysed juices and nectars, with average concentration ranging from 1.34 mg/kg in orange juices (glass) to 4.26 mg/kg in black currant nectar (glass). Fruit juices and nectars kept in tetra pack packaging were characterised by elevated concentrations of Al and Sb, while the products in glass packaging contained significantly higher concentrations of As compared with the products in tetra pack packaging. Although the average concentrations of trace elements were lower than the standard limit, exposure to non-carcinogenic factors was demonstrated.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sandra Bravo Martín-Consuegra ◽  
Jose A. Amorós Ortíz-Villajos ◽  
Caridad Pérez-de-los-Reyes ◽  
Francisco J. García Navarro ◽  
Rolando Ruedas Luna ◽  
...  

The study of five soil profiles developed on carbonatic sediments of Tertiary Miocene origin has been carried out. The topography of the area was basically flat and the traditional uses of the soils are the cultivation of dry cereals and grapevine. The geochemical characterization of the aforementioned profiles involves a study of the contents of major and trace elements among other pedologic aspects (texture, pH, organic matter, etc.). The results of this study also indicate a superficial enrichment of trace elements due to the leaching of Ca and moderate biological and anthropic activity. We can consider strontium, Sr, as the trace element that characterizes these limy soils (435 mg/kg average content in total soil and 708 mg/kg in the original rock). These contents are similar to the average value in Castilla-La Mancha of 380 mg/kg and are higher than the average in world soils of about 200 mg/kg. High levels of dangerous or pollutant elements (Cd, Hg, Pb, Cu, Zn, or Ni) were not detected. The majority of trace element anomalies are related to calcareous material and the leaching of calcium carbonate (Ca), while the influence of the anthropogenic factor is secondary. Soil quality does not indicate toxicity although surficial enrichment suggests a weak threat from consuming crops.


2019 ◽  
pp. 337-347
Author(s):  
Ol'ga Aleksandrovna Golubina ◽  
Tat'yana Nikolayevna Tsybukova ◽  
Elena Nikitichna Tveryakova ◽  
Irina Aleksandrovna Perederina ◽  
Galina Aleksandrovna Zholobova ◽  
...  

Peats and marsh waters of the peat bog eutrophic ecosystem (Tomsk region) for the content of trace elements have been studied. The peat deposit is composed of lowland peats of grass type predominantly. The deposit average depth is about 3 meters. Samples of several observation points, which differ in botanical composition and hydrothermal conditions of occurrence were analyzed. The concentration of biogenic (Zn, Co, Cr), alkaline (Rb, Cs), alkaline earth (Sr, Ba) and rare earth (Hf, La) metals in peat and marsh waters has been determined by the method of neutron activation analysis. It was shown that the amount of various elements in peat is determined by regional characteristics and botanical composition. From comparative elements concentration analysis, it has been found that concentration of metals varies identically depending on the depth of the peat bog, which indicates typical conditions for the accumulation of these elements. As a result of the research was founded high content of the Ba and Sr in peats of all observation points. It has been established that the peat of native section 3 is enriched with all studied metals Zn, Cr, Sr, Ba in comparison with peats of the first and the second observation points. Besides, under the conditions of this ecosystem cobalt, rubidium and lanthanum were accumulated in peats. The average concentration of trace elements in the studied peat bog ecosystem is comparable to the average values of this region. We have found that samples of marsh water are enriched with the biogenic zinc. Among rare metals, such elements as strontium and barium are the most abundant in marsh water, what correlates with the largest content of Zn, Sr and Ba in the studied peats. Light Rb and Sr ions transfer from peat to swamp waters in greater amount than heavier Cs and Ba ions. Strontium enters and migrates intensively to the swamp waters of all three observation points.


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