Mineralogical and geochemical evolution of the Bidgol bauxite deposit, Zagros Mountain Belt, Iran: Implications for ore genesis, rare earth elements fractionation and parental affinity

2017 ◽  
Vol 86 ◽  
pp. 755-783 ◽  
Author(s):  
Farhad Ahmadnejad ◽  
Hassan Zamanian ◽  
Batoul Taghipour ◽  
Alireza Zarasvandi ◽  
Roberto Buccione ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Geochemical Evolution ◽  
Bauxite Deposit ◽  
Ore Genesis ◽  
Zagros Mountain ◽  
Mountain Belt

scholarly journals Geochemical Characteristics and Tectonic Setting of Amphibolites in Ifewara Area, Ife-Ilesha Schist Belt, Southwestern Nigeria

2016 ◽  
Vol 6 (1) ◽  
pp. 43 ◽  
Author(s):  
Anthony Temidayo Bolarinwa ◽  
Adebimpe Atinuke Adepoju
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Major Element ◽  
Tectonic Setting ◽  
Crustal Contamination ◽  
Geochemical Evolution ◽  
Schist Belt ◽  
Southwestern Nigeria ◽  
Eu Anomaly ◽  
Ree Patterns

Trace and Rare Earth Elements (REEs) data are used to constrain the geochemical evolution of the amphibolites from Ifewara in the Ife-Ilesha schist belt of southwestern Nigeria. The amphibolites can be grouped into banded and sheared amphibolites. Major element data show SiO2 (48.34%), Fe2O3 (11.03-17.88%), MgO (5.76-9.90%), CaO (7.76-18.6%) and TiO2 (0.44-1.77%) contents which are similar to amphibolites in other schist belts in Nigeria. The Al2O3 (2.85-15.55%) content is varied, with the higher values suggesting alkali basalt protolith. Trace and rare earth elements composition reveal Sr (160-1077ppm), Rb (0.5-22.9ppm), Ni (4.7-10.2ppm), Co (12.2-50.9 ppm) and Cr (2-7ppm). Chondrite-normalized REE patterns show that the banded amphibolites have HREE depletion and both negative and positive Eu anomalies while the sheared variety showed slight LREE enrichment with no apparent Eu anomaly. The study amphibolites plot in the Mid Oceanic Ridge Basalts (MORB) and within plate basalt fields on the Zr/Y vs Zr discriminatory diagrams. They are further classified as volcanic arc basalt and E-type MORB on the Th- Hf/3- Ta and the Zr-Nb-Y diagrams. The amphibolites precursor is considered a tholeiitic suite that suffered crustal contamination, during emplacement in a rifted crust.

scholarly journals Allanite Geochemical Response to Hydrothermal Alteration by Alkaline, Low-Temperature Fluids

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 392 ◽  
Author(s):  
Katarzyna Gros ◽  
Ewa Słaby ◽  
Petras Jokubauskas ◽  
Jiří Sláma ◽  
Gabriela Kozub-Budzyń
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Rare Earth Elements ◽  
Geochemical Evolution ◽  
Additional Component ◽  
Second Stage ◽  
Ce Anomaly ◽  
Hydrothermal Processes ◽  
Fluid Infiltration ◽  
Two Stages

Allanite is one of the main rare earth elements (REE)-rich accessory minerals in composite dykes from the granitoid pluton of Karkonosze. These dykes differ in composition from the bulk of the pluton by elevated rare earth elements (REE), Y, Zr, and alkali contents, suggesting contribution of an additional component. Allanite exhibits complex alteration textures, which can be divided into two stages. The first stage is represented by allanite mantles, formed by fluid infiltration into previously crystallized magmatic allanite. These zones have low totals, are Ca-, Al-, Mg-, and light REE (LREE)-depleted, and Y-, heavy REE (HREE)-, Th-, Ti-, and alkali-enriched. The fractionation between LREE and HREE was caused by different mobility of complexes formed by these elements in aqueous fluids. The second stage includes recrystallized LREE-poor, Y-HREE-rich allanite with variable Ca, Al, Mg, and REE-fluorocarbonates. The alteration products from both stages demonstrate higher Fe3+/(Fe2+ + Fe3+) ratios and a negative Ce anomaly. These features point to the alkaline, low-temperature, and oxidized nature of the fluids. The differences in mobility and solubility of respective ligands show that the fluids from the first stage may have been dominated by Cl, whereas those of the second stage may have been dominated by F and CO2 (and PO4 in case of one sample). The inferred chemistry of the fluids resembles the overall geochemical signature of the composite dykes, indicating a major contribution of the hydrothermal processes to their geochemical evolution.

Geochemical evolution of the Chatham–Grenville stock, Quebec

1985 ◽  
Vol 22 (6) ◽  
pp. 872-880 ◽  
Author(s):  
Michael Denis Higgins
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mass Balance ◽  
Major Element ◽  
Parental Magma ◽  
Alkali Feldspar ◽  
Geochemical Evolution ◽  
Wide Range ◽  
The Mean

The Chatham–Grenville stock is an anorogenic multiple intrusion that shows a complete gradation from early cumulate and noncumulate syenites to slightly peralkaline granites. It can be divided into four units. Unit 1, the first unit, is a noncumulate syenite with modal quartz less than 5%. Unit 2 has a wide range in composition from cumulate syenites (no modal quartz) to noncumulate syenites and quartz syenites (modal quartz = 20%). Units 3 and 4 are granites with modal quartz up to 25 and 30%, respectively. The parental magma of the whole complex was syenitic. Differentiation occurred as a result of crystal fractionation by filter pressing both at depth and in situ. Ba, Sr, Rb, and Eu abundances and major-element mass-balance calculations show that alkali feldspar, mafic minerals, and apatite were fractionated. At least 79% fractionation is necessary to transform the mean composition of the first unit (1) into the mean composition of the last unit (4). The rare-earth elements, Th, Ta, Hf, and Zr, did not behave in a residual fashion but may have been fractionated in minor accessory phases such as apatite, zircon, monazite, allanite, and xenotime.

Corundum (sapphire) and zircon relationships, Lava Plains gem fields, NE Australia: Integrated mineralogy, geochemistry, age determination, genesis and geographical typing

2015 ◽  
Vol 79 (3) ◽  
pp. 545-581 ◽  
Author(s):  
F. L. Sutherland ◽  
R. R. Coenraads ◽  
A. Abduriyim ◽  
S. Meffre ◽  
P. W. O. Hoskin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Field Strength ◽  
Rare Earth Elements ◽  
Trace Element ◽  
High Field ◽  
Age Determination ◽  
Silicate Melts ◽  
Geochemical Evolution ◽  
High Field Strength ◽  
Zircon Formation

AbstractGem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.

scholarly journals SEQUENTIAL EXTRACTION OF RARE EARTH ELEMENTS TO EVALUATE POST-DEPOSITIONAL GEOCHEMICAL EVOLUTION IN MARCELLUS SHALE

2017 ◽  
Author(s):  
Thai T. Phan ◽  
◽  
J. Alexandra Hakala ◽  
J. Alexandra Hakala ◽  
Christina L. Lopano ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Sequential Extraction ◽  
Marcellus Shale ◽  
Geochemical Evolution
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