scholarly journals Geochemical Characterization of Mineralized Pegmatites around Wowyen Areas, Akwanga, Northcentral Nigeria

Author(s):  
Anthony Chukwu

This study aims to account for the petrogenesis and mineralization of pegmatites around the Wowyen area, northcentral basement complex,Nigeria. Field studies, petrography and whole rock geochemistry (Major oxides were estimated by X-Ray Fluorescence while the trace elements were estimated by Inductively Coupled Plasma Mass Spectrometry) where the methods adopted. The pegmatites around Wowyen area are emplaced in the remobilized belt of the Nigerian Basement complex. They are predominantly complex pegmatites (rare-metal pegmatites) which are intruded in the biotite-muscovite gneiss while the simple pegmatites intruded more in the migmatitic banded gneiss. The major components of the complex pegmatites are quartz, albite and muscovite and tourmaline.The accessory constituents are garnet; ilmenites; cassiterite-columbitetantalite oxides in contrast to quartz, microcline and biotite of the simple pegmatites. The complex pegmatites show higher peraluminous than the simple pegmatites, however, higher fractionation is observed in the complex pegmatites than the simple pegmatites. The complex pegmatites are rather enriched in rare elements such as Li, Rb, B, Cs, Sn, Nb, Be and Ta and show low ratios in Al/Ga and K/Rb than the simple pegmatites. The pegmatites are likely product of sedimentary origin and originated from post-collisional tectonic event.

Archaeometry ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 35-46 ◽  
Author(s):  
D. J. Kennett ◽  
A. J. Anderson ◽  
M. J. Cruz ◽  
G. R. Clark ◽  
G. R. Summerhayes

2021 ◽  
Author(s):  
Frederico Sousa Guimarães ◽  
Rongqing Zhang ◽  
Bernd Lehmann ◽  
Alexandre Raphael Cabral ◽  
Francisco Javier Rios

Abstract The Mesoproterozoic Rondônia Tin Province of the Amazonian craton records a protracted history of about 600 m.y. of successive rare-metal granite intrusions and hosts the youngest known event of tin-granite emplacement of the craton—a rare-metal granite suite known as the Younger Granites of Rondônia intrusive suite. The ~1 Ga suite is currently interpreted as intracratonic magmatism resulting from a Grenvillian-age orogeny during the assembly of Rodinia. The Santa Bárbara massif is a tin-granite system of the Younger Granites of Rondônia intrusive suite that hosts Sn-Nb-Ta-W–bearing endogreisen and stockwork, as well as important placer deposits. The Santa Bárbara mine produces about 800 to 1,000 t Sn/year from placers and weathered greisen and represents about 20% of the tin mine output of the Rondônia Tin Province. Here, we report laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) cassiterite U-Pb ages of 989 ± 3 and 987 ± 6 Ma for the Santa Bárbara greisen and the cassiterite-quartz vein system, respectively. Alluvial cassiterite from placer mining has a U-Pb age of 995 ± 4 Ma, which is, within uncertainty, indistinguishable from those of primary cassiterite. These ages agree well with the previously published zircon and monazite U-Pb ages for the Santa Bárbara granite (978 ± 13 and 989 ± 13 Ma), which indicate a coeval relationship between hydrothermal tin mineralization and granite magmatism. The previously suggested 20- to 30-m.y. time span between granite magmatism and hydrothermal tin mineralization, which was based on mica K-Ar and Ar-Ar age data, is likely due to younger thermal disturbance of the isotopic systems.


2020 ◽  
Vol 35 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Eduardo Bolea-Fernandez ◽  
Ana Rua-Ibarz ◽  
Milica Velimirovic ◽  
Kristof Tirez ◽  
Frank Vanhaecke

The occurrence of microplastics (MPs) in the environment is a matter of increasing concern. In this work, it has been shown for the first time that ICP-MS operated in single-event mode can be used for the characterization of MPs relying on their C content.


Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 535
Author(s):  
Franca Piera Caucia ◽  
Luigi Marinoni ◽  
Maurizio Scacchetti ◽  
Maria Pia Riccardi ◽  
Omar Bartoli

In Val d’Ala (Western Alps in Piedmont, Italy), the most interesting rocks for mineralogical research are represented by rodingite (rich in mineralized veins and fractures) associated with serpentinite in the eclogitized oceanic crust of Piedmont Zone, south of Gran Paradiso Massif. Among the vein-filling minerals, vesuvianite is well appreciated for its potential as gem-quality materials, even though it has never been characterized in detail. This study provides a gemological characterization of eleven vesuvianite crystals from different localities of the Val d’Ala. The refractive index (1.717–1.708) and density (1.705–1.709) values of our vesuvianite are in the range of those in the literature. Scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) established that the samples are pretty compositionally homogeneous in terms of major elements, while trace and rare earth elements (REE) contents are more variable. All REE patterns are characterized by pronounced positive Eu anomalies. The variations in color (from olive green to dark green with chocolate (reddish-brown color shades and polychrome bands) are due to the relevant presence of Fe and, to a lesser extent, Ti and Cr. The X-ray powder diffraction (XRPD) analyses and SEM/EDS quantitative study indicate that the other phases associated with vesuvianite are represented by diopside, garnet, clinochlore.


Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 635
Author(s):  
Aashvi Dudhaiya ◽  
Fatima Haque ◽  
Hugo Fantucci ◽  
Rafael M. Santos

Wollastonite is a natural silicate mineral that can be used as an agricultural soil amendment. Once in the soil, this mineral undergoes weathering and carbonation reactions, and, under certain soil and field crop conditions, our previous work has shown that this practice leads to accumulation of inorganic carbon (calcium carbonate). Mineral carbonation is the carbon sequestration approach with the greatest potential for sequestration capacity and permanency. Agricultural lands offer vast areas onto which such minerals can be applied, while benefiting crops. This work illustrates a technique to separate wollastonite-containing soils into different fractions. These fractions are characterized separately to determine organic and inorganic content, as well as to determine the chemical and mineral composition. The aim is to detect the fate of wollastonite in agricultural soils, and the fate of weathering/carbonation products in the soil. The soils used in the study were collected from soybean and potato farmlands in Southern Ontario, and from an experimental pilot plot. Soil fractionation was done using sieving, and soil fractions were analyzed by a calcimeter, X-ray diffraction, and loss-on-ignition. Acid digested samples were measured by Inductively Coupled Plasma Mass Spectrometry. Carbonates and wollastonite were enriched by fractionation.


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