Geochemistry of Selected Kaolins from Cameroon and Nigeria

AbstractThe geochemical characteristics of selected kaolins from Cameroon and Nigeria are presented, with an attempt to elucidate on their possible industrial applications by comparing them to world-known kaolin deposits. Major oxides concentrations were subjected to factor analyses in interpreting their relationships. Geochemical indices, including chemical index of alteration (CIA), chemical index of weathering (CIW) and the index of compositional variability (ICV) were computed and plotted on binary and ternary diagrams to determine the intensity of weathering of the kaolins and discriminate their different source rock types. Kaolinite was the major phase, followed by quartz, illite and goethite as minor phases. Minerals in trace phases included smectite, anatase, muscovite, gibbsite, microcline, palygorskite and calcite. Mean abundances of major oxides in wt% were: SiO

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X-RAY FLUORESCENCE AND STABLE ISOTOPES ANALYSES OF IKPESHI MARBLE, SOUTH SOUTHERN NIGERIA

African Journal of Science and Nature ◽

10.46881/ajsn.v10i0.183 ◽

2020 ◽

Vol 10 ◽

pp. 102

Author(s):

Phillips Reuben Ikhane ◽

Olalekan Olayiwola Oyebolu ◽

Afolabi Omotayo Alaka

Keyword(s):

Stable Isotopes ◽

Stable Isotope ◽

Precipitation Process ◽

Dolomitic Marble ◽

X Ray ◽

Humid Condition ◽

Major Oxides ◽

Chemical Index ◽

Isotopic Analyses ◽

Chemical Index Of Alteration

Integration of X-ray fluor escence and stable isotope spectrometric techniques for quality assessment and provenance study of exposed marble deposit at Fakunle Quarry, Ikpeshi, South Western Nigeria constitute the fundamental aims of this research. Fourteen fresh (14) marble samples obtained at different localities within the quarry were subjected to geochemical and isotopic analyses to ascertain the quantitative abundance of major oxides and stable isotopes using X-Ray Fluorescence and Thermo Fisher mass spectrometer respectively. The major oxides revealed by XRF analysis of the marble samples are CaO, MgO, SiO2, Al2O3, Fe2O3 and Na2O with percentage composition ranging between 11.66 – 13.25, 7.75 – 9.65, 41.36 – 47.55, 12.36 – 15.23, 7.79 – 10.55 and 1.44 – 1.75respectively. Na2O + K2O value ranges between 1.48 and 1.78.The classification of marble in relation to percentage of calcite-dolomite indicate a percentage range of -5 to 4% and 93-103% for Calcite and Dolomite respectively. Chemical Index of Alteration (CIA) ranges from 45.16 to 51.59 % and Chemical Index of Weathering (CIW) ranges from 46.19 to 52.30 %. Stable isotope ( ? –180) of marble ranges from -10.50 to -7.00 with a corresponding value from 25.50 to 55.33.Interpretation of the overall results indicates an impure quartz-rich dolomitic marble; metamorphosed from a low carbonate sedimentary/meta sedimentary protolith which shallowly precipitated within a passive marginal marine environment under humid condition. The high silica impurity can however be attributed to the inordinate influx of terrigenous sediments during the precipitation process. Weathering effect is minimal on the marble deposit. Conclusively, strong correlation is apparent between the obtained geochemical result and the basement geology of the study area.

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Potassium-metasomatism in Anthracite: A Cluster of Geochemical Evidences

10.21203/rs.3.rs-832423/v1 ◽

2021 ◽

Author(s):

Santanu Ghosh ◽

Anwita Ojha ◽

Atul Kumar Varma

Keyword(s):

Source Rock ◽

Chemical Weathering ◽

Bituminous Coal ◽

Climatic Conditions ◽

Rock Composition ◽

Thrust Belts ◽

Chemical Index ◽

Parent Rocks ◽

Chemical Index Of Alteration ◽

The Fourier Transform

Abstract The present study focuses on the inorganic geochemical features of the bituminous coal samples from the Raniganj and the Jharia Basin, as well as the anthracite samples from the Himalayan fold-thrust belts of Sikkim, India. The SiO2 content (48.05 to 65.09 wt% in the ash yield of the bituminous coal samples and 35.92 to 50.11 wt% in the ash yield of the anthracite samples) and the ratio of Al2O3/TiO2 (6.97 to 17.03 in the bituminous coal samples and 10.34 to 20.07 in the anthracite samples) reveal the intermediate igneous source rock composition of the minerals. The ratio of the K2O/Al2O3 in the ash yield of the bituminous coal samples (0.03 to 0.09) may suggest the presence of kaolinite mixed with montmorillonite, while its range in the ash yield of the anthracite samples (0.16 to 0.27) may imply the presence of illite mixed with kaolinite. The chemical index of alteration values may suggest the moderate to strong chemical weathering of the source rock under sub-humid to humid climatic conditions. The plot of the bituminous coal samples in the A-CN-K diagram depicts the traditional weathering trend of parent rocks, but the anthracite samples plot near the illite field and are a bit offset from the weathering trend. This may imply the plausible influences of the potassium-metasomatism at post coalification stages. The Fourier transform infrared spectra further reveal the hydroxyl stretching intensity of the illite in the anthracite samples substantiating the effect of the epigenetic potassium-metasomatism. The decrease in total kaolinite intensity/compound intensity of quartz and feldspar may provide additional evidence towards this epigenetic event.

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Environmental Geochemical Assessment of Ogbagha River Sediments in Okpella Area of Edo State, Nigeria

Journal of Applied Sciences and Environmental Management ◽

10.4314/jasem.v24i2.21 ◽

2020 ◽

Vol 24 (2) ◽

pp. 335-340

Author(s):

S.O. Obanje ◽

S.A. Adelowo

Keyword(s):

Source Rock ◽

Environmental Remediation ◽

River Sediments ◽

Environmental Geochemistry ◽

Major And Trace Elements ◽

Mean Values ◽

Chemical Index ◽

Chemical Index Of Alteration ◽

Edo State ◽

Geochemical Assessment

The main aim of this paper is the environmental geochemical assessment of Ogbagha river sediments to ascertain the level of their pollution. The study area lies between latitude 7°14’N and 7°22’N and longitude 6°15’E and 6°23’E in Okpella area of Edo State, Nigeria. Major and trace elements in the six composite samples collected were analysed using Epsilon-5 x-ray fluorescence model (pAnalytical). SiO2 values range from71.4-81.61 wt. % with mean of 75.71 wt %, while Al2O3 values range from 7.01-12.97 wt. % with mean values of 11.56 wt. %.The other major oxides are below 7.00 wt. %. SiO2 and Al2O3 wt. % values are indicative of felsic source rock. The mean concentration values of Zr (1,830.55 ppm), Ba (1,416.00 ppm) and Cu (77.17 ppm) are higher than their crustal baseline values. Conversely, Sr (295.00 ppm), In (106.00 ppm), As (14.83 ppm), Cr (8.53 ppm), Co (7.00 ppm), Pb (13.33 ppm) have lower average concentrations than their crustal baseline average concentrations. Chemical index of alteration values for the samples also pointed to felsic source rock(s). The index of geoaccumulation values of Sb, In, Zr is indicative of serious environmental geochemical concern in the study area. However, potentially toxic elements such as Cu, Cr, Co, Pb, etc. are below the pollution baseline. It is recommended that standard environmental remediation measures should be taken to mitigate the pollution impact of In, Sb and Zr in the study area. Keywords: Ogbagha-Okpella, environmental geochemistry, enrichment ratios, geoaccumulation index

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Permo-Carboniferous Climate Change: Geochemical Evidences from Lower Gondwana Glacial Sediments, Rangit Valley, Sikkim Lesser Himalaya, India

Journal of Climate Change ◽

10.3233/jcc210001 ◽

2021 ◽

Vol 7 (1) ◽

pp. 1-11

Author(s):

Raj Kumar Priya ◽

Vinod Chandra Tewari ◽

Rakesh Kumar Ranjan

Keyword(s):

Climate Change ◽

Chemical Weathering ◽

Depositional Environment ◽

Lesser Himalaya ◽

Glacial Sediments ◽

Source Areas ◽

Chemical Index ◽

Chemical Index Of Alteration ◽

Compositional Variability ◽

Stratigraphic Sequences

The Rangit Gondwana Basin of Sikkim in the lesser Himalaya witnessed a wide span of climate change during the Permo-Carboniferous period. The principal objective of the present study is to document this Permo-Carboniferous climate change in the form of a geochemical signature preserved in the siliciclastic facies of the Rangit Pebble Slate Formation. The stratigraphic sequences of the Rangit Gondwana Basin are categorically well defined and subdivided into upper and lower sequences on the basis of their depositional environment. The lower sequences of the Rangit Gondwana basin are comprised of massive diamictite with large stromatolitic dolomite boulders and dropstone embedded in the coarser sandstone which indicate the cold glaciomarine environment of deposition, whereas upper sequences consist of repeated alternate beds of sandstone, black shale and coal seam with a regular interval depicting the fluvial and deltaic environment of deposition. The enrichment of SiO2, Al2O3, TiO2, MnO, MgO, and K2O indicates that these sediments were mostly derived from felsic rock source areas. Chemical Index of Alteration (CIA) and Index of Compositional Variability (ICV) CaO + Na2O + K2O/Al2O3, and SiO2 vs. (Al2O3 + K2O + Na2O) values suggest that the sediments maturity and paleoclimatic environment deposition of the sediments of lower sequences was cold and semi-humid whereas the deposition of sediments of upper sequences was warm and humid. The A-CN-K ternary plot and CIA vs ICV binary plot also indicate and verify that the source areas were subjected to prolonged intense chemical weathering from low to high grade due to shifting of cold to warm humid paleo-climatic condition.

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PROVENANCE, TEXTURE, AND RELATIVE AGE CONTROLS ON THE CHEMICAL INDEX OF ALTERATION (CIA) IN PLEISTOCENE TILLS, MINNESOTA USA

10.1130/abs/2018nc-313117 ◽

2018 ◽

Author(s):

Chad Wittkop ◽

◽

Christian Piper ◽

Julie K. Bartley ◽

Russell Krueger ◽

...

Keyword(s):

Relative Age ◽

Chemical Index ◽

Chemical Index Of Alteration

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Compositional variability of regoliths on equatorial highlands (East Timor). Source-rock control and competing effects of weathering and denudation

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2020.104658 ◽

2020 ◽

pp. 104658

Author(s):

Pedro A. Dinis ◽

José Sá Pereira ◽

Eduardo Ivo Alves ◽

João Serra Pratas

Keyword(s):

Source Rock ◽

East Timor ◽

Compositional Variability

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Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas State, northwestern Gulf of Mexico

Journal of Palaeogeography ◽

10.1186/s42501-021-00101-4 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Mayla A. Ramos-Vázquez ◽

John S. Armstrong-Altrin

Keyword(s):

Gulf Of Mexico ◽

Age Groups ◽

Source Area ◽

Detrital Zircons ◽

Sediment Provenance ◽

Geochemical Composition ◽

Chemical Index ◽

Beach Sediments ◽

Chemical Index Of Alteration ◽

Ree Patterns

AbstractThe mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo (Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite, zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element (REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly (Eu/Eu* = ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments, respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic (~ 2039–595 Ma), Mesozoic (~ 244–70.3 Ma), and Cenozoic (~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province (EAP) and Mesa Central Province (MCP). Similarly, the likely sources for the Proterozoic zircons were the Sierra Madre Oriental (SMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

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