• Title/Summary/Keyword: Rare Earth

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Geochemistry and Petrogenesis of Pan-african Granitoids in Kaiama, North Central, Nigeria

  • Aliyu Ohiani Umaru;Olugbenga Okunlola;Umaru Adamu Danbatta;Olusegun G. Olisa
    • Economic and Environmental Geology
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    • v.56 no.3
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    • pp.259-275
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    • 2023

  • Pan African granitoids of Kaiama is comprised of K-feldspar rich granites, porphyritic granites, and granitic gneiss that are intruded by quartz veins and aplitic veins and dykes which trend NE-SW. In order to establish the geochemical signatures, petrogenesis, and tectonic settings of the lithological units, petrological, petrographical, and geochemical studies was carried out. Petrographic analysis reveals that the granitoids are dominantly composed of quartz, plagioclase feldspar, biotite, and k-feldspar with occasional muscovites, sericite, and opaque minerals that constitute very low proportion. Major, trace, and rare earth elements geochemical data reveal that the rocks have moderate to high silica (SiO2=63-79.7%) and alumina (Al2O3=11.85-16.15) contents that correlate with the abundance of quartz, feldspars, and biotite. The rocks are calc-alkaline, peraluminous (ASI=1.0-<1.2), and S-type granitoids sourced by melting of pre-existing metasedimentary or sedimentary rocks containing Al, Na, and K oxides. They plot dominantly in the WPG and VAG fields suggesting emplacement in a post-collisional tectonic setting. On a multi-element variation diagram, the granitoids show depletion in Ba, K, P, Rb, and Ti while enrichment was observed for Th, U, Nd, Pb and Sm. Their rare-earth elements pattern is characterized by moderate fractionation ((La/Yb)N=0.52-38.24) and pronounced negative Eu-anomaly (Eu/Eu*=0.02-1.22) that points to the preservation of plagioclase from the source magma. Generally, the geochemical features of the granitoids show that they were derived by the partial melting of crustal rocks with some input from greywacke and pelitic materials in a typical post-collisional tectonic setting.

  • https://doi.org/10.9719/EEG.2023.56.3.259 인용 PDF

Properties and Recovery Technologies for Rare-Platinum Group using Patent Information (특허정보(特許情報)를 이용한 희소백금족(稀少白金族) 특성(特性)과 회수기술(回收技術))

  • Ahn, Jong-Gwan;Lee, Kang-Myoung;Lee, Jae-Ryeong
    • Resources Recycling
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    • v.18 no.4
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    • pp.3-13
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    • 2009

  • Rare platinum group (RPG)including rhodium, ruthenium, iridium, osmium, exists at the rate of 0.4 ppb or less in the earth's crust. For the purpose of suggestion to developing necessity for recycling technology with the RPG, survey on the characteristics and the recovery technologies was carried out by using patent information.

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Application of Electron Spectroscopies for Thin Film Analysis

  • Hua, Z.Y.
    • Journal of the Korean Vacuum Society
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    • v.2 no.3
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    • pp.384-390
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    • 1993

  • A number of different thin-film analytical method using electron spectroscopies are reviewed and evaluated. Results from various kinds of films (e.g. superconductive, electron-emissive, amorphous, rare-earth containing, etc.) are given for illustration. The existing quantification problems from this technology and some approaches for solving them are also discussed.

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