scholarly journals Geochemistry of the Serra das Melancias Pluton in the Serra da Aldeia Suite: a classic post-collisional high Ba-Sr granite in The Riacho do Pontal Fold Belt, NE Brazil

2016 ◽  
Vol 46 (2) ◽  
pp. 221-237 ◽  
Author(s):  
Marcela Paschoal Perpétuo ◽  
Wagner da Silva Amaral ◽  
Felipe Grandjean da Costa ◽  
Evilarde Carvalho Uchôa Filho ◽  
Daniel Francisco Martins de Sousa
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Geochemical Data ◽  
Fold Belt ◽  
Heavy Rare Earth ◽  
Pan African ◽  
High K ◽  
Heavy Rare Earth Elements ◽  
Brasiliano Orogeny ◽  
Light Rare Earth Elements

ABSTRACT: The Serra da Aldeia Suite is composed by circular or oval-shaped plutons, intrusive in meta-sedimentary and meta-volcanosedimentary rocks in the Riacho do Pontal Fold Belt, NE Brazil. The Serra das Melancias Pluton, belonging to Serra da Aldeia Suite, is located southeastern of Piaui state, near Paulistana city. These plutons represent a major magmatic expression in this area and contain important information about the late magmatic/collisional geologic evolution of the Brasiliano Orogeny. Based on petrographic and geochemical data, three facies were defined in the Serra das Melancias Pluton: granites, syenites and quartz monzonites. The rocks display high-K and alkaline to shoshonitic affinities, are metaluminous and show ferrous character. They are enriched in Light Rare Earth Elements and Large Ion Lithophile Elements, with negative anomalies in Nb, Ta and Ti. Their high Ba, Sr, K/Rb, low Rb, relatively low U, Th, Nb to very low Heavy Rare Earth Elements and Y resemble those of typical high Ba-Sr granitoids. The geochemical data suggest the emplacement of Serra das Melancias Pluton in a transitional, late to post-orogenic setting in the Riacho do Pontal Fold Belt during the late Brasiliano-Pan African Orogeny.

scholarly journals Rare earth elements and stable sulphur (δ34s) isotope of baryte mineralization in Liji Area, Northern Benue trough, northeastern Nigeria

2020 ◽  
Vol 39 (3) ◽  
pp. 687-693
Author(s):  
H.I. Kamale ◽  
J.M. El-Nafaty ◽  
A.O. Umaru ◽  
B. Shettima ◽  
M.U. Obidiegwu
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Isotope Geochemistry ◽  
Sulphur Isotope ◽  
Benue Trough ◽  
Granite Pegmatite ◽  
Sedimentary Deposits ◽  
Pan African ◽  
Heavy Rare Earth Elements ◽  
Light Rare Earth Elements

The Liji area lithologically consists of inliers of granite and pegmatite members of the Pan-African granitoids surrounded by Cretaceous sedimentary deposits of Bima, Yolde, Pindiga and Gombe Formations. Epigenetic fracture-filling baryte mineralization hosted by granite, pegmatite and Bima Sandstone were delineated, sampled and analyzed for rare-earth elements (REEs) and stable sulphur isotope geochemistry. The REEs of the distal (unaltered) rocks indicated normal values (26.15-36.81 ppm) before mineralization was marked by enrichment of light rare-earth elements (LREEs) (27.94 ppm) relative to the heavy rare-earth elements (HREEs) (5.34 ppm) and negative Eu anomalies typical of calc-alkaline granites of Pan-African age. The baryte separates were marked by enriched LREEs and depleted HREEs with pronounced positive Eu anomalies indicating the invasion and consequent deposition of baryte-rich hydrothermal fluid under oxidizing conditions in the N-S and E-W striking fractures. Stable sulphur isotope of the baryte gives values that ranged from 18.3 - 19.8o/oo CDT indicating that the source of sulphur is from ocean water and not from magmatic, fresh water and connate water sources from the nearby granite, pegmatite and sandstone. Keywords: Baryte, Mineralization, Hydrothermal, Liji, REE, Sulphur-Isotope.

Selective recovery of heavy rare earth elements from apatite with an adsorbent bearing immobilized tridentate amido ligands

2016 ◽  
Vol 159 ◽  
pp. 157-160 ◽  
Author(s):  
Takeshi Ogata ◽  
Hirokazu Narita ◽  
Mikiya Tanaka ◽  
Mihoko Hoshino ◽  
Yoshiaki Kon ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Heavy Rare Earth ◽  
Amido Ligands ◽  
Selective Recovery ◽  
Heavy Rare Earth Elements

scholarly journals Effect of acid mine drainage on dissolved rare earth elements geochemistry along a fluvial–estuarine system: the Tinto-Odiel Estuary (S.W. Spain)

2012 ◽  
Vol 43 (3) ◽  
pp. 262-274 ◽  
Author(s):  
J. Borrego ◽  
B. Carro ◽  
N. López-González ◽  
J. de la Rosa ◽  
J. A. Grande ◽  
...  
Keyword(s):  
Rare Earth ◽  
Acid Mine Drainage ◽  
Rare Earth Elements ◽  
Mine Drainage ◽  
Drainage System ◽  
Estuarine System ◽  
Mixing Zone ◽  
Heavy Rare Earth ◽  
Acid Mine ◽  
Heavy Rare Earth Elements

The concentration of rare earth elements together with Sc, Y, and U, as well as rare earth elements fractionation patterns, in the water of an affected acid mine drainage system were investigated. Significant dissolved concentrations of the studied elements were observed in the fluvial sector of this estuary system (Sc ∼ 31 μg L−1, Y ∼ 187 μg L−1, U ∼ 41 μg L−1, Σ rare earth elements ∼621 μg L−1), with pH values below 2.7. In the mixing zone of the estuary, concentrations are lower (Sc ∼ 2.1 μg L−1; Y ∼ 16.7 μg L−1; U ∼ 4.8 μg L−1; Σ rare earth elements ∼65.3 μg L−1) and show a strong longitudinal gradient. The largest rare earth elements removal occurs in the medium-chlorinity zone and it becomes extreme for heavy rare earth elements, as observed for Sc. Samples of the mixing zone show a North American Shale normalized pattern similar to the fluvial zone water, while the samples located in the zone with pH between 6.5 and 7.7 show a depletion of light rare earth elements relative to middle rare earth elements and heavy rare earth elements, similar to that observed in samples of the marine estuary.

scholarly journals Separation and Adsorption-Desorption Characteristics of Heavy Rare Earth Elements (Gd, Tb, Dy) using P507 Resin

2016 ◽  
Vol 25 (4) ◽  
pp. 60-67
Author(s):  
Sungeun Lee ◽  
Joung Woon Kim ◽  
Jong Hyuk Jeon ◽  
Hong Myeong Jun ◽  
Jin Young Lee ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Elements ◽  
Adsorption Desorption

High specific surface 1-(2-pyridylazo) 2-naphthol (PAN) modified Carbon-based silicon film with cellulose nanocrystalline structure for efficient adsorption of rare earth elements

2021 ◽  
Author(s):  
Bin Wang ◽  
Yuzhe Zhang ◽  
Wen Sun ◽  
Xudong Zheng ◽  
Zhongyu Li
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Specific Surface ◽  
Cellulose Nanocrystals ◽  
Silicon Film ◽  
Nanocrystalline Structure ◽  
Heavy Rare Earth ◽  
Beneficial Result ◽  
Waste Products ◽  
Heavy Rare Earth Elements

The recovery of rare earth elements, especially heavy rare earth elements, from rare earth waste products has a high economic and environmental beneficial result. In this paper, cellulose nanocrystals used...

Petrogenesis of the Upper Cretaceous volcanism in the Kefken region, Western Pontides, NW Turkey

2021 ◽  
Author(s):  
Turgut Duzman ◽  
Ezgi Sağlam ◽  
Aral I. Okay
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Partial Melting ◽  
Upper Cretaceous ◽  
Volcanic Rocks ◽  
Early Eocene ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Elements ◽  
Cretaceous Volcanism ◽  
Oceanic Slab

<p>The Upper Cretaceous volcanic and volcaniclastic rocks crop out along the Black Sea coastline in Turkey. They are part of a magmatic arc that formed as a result of northward subduction of the Tethys ocean beneath the southern margin of Laurasia. The lower part of the Upper Cretaceous volcanism in the Kefken region, 100 km northeast of Istanbul, is represented by basaltic andesites, andesites, agglomerates and tuffs, which have yielded Late Cretaceous (Campanian, ca. 83 Ma) U-Pb zircon ages. The volcanic and volcanoclastic rocks are stratigraphically overlain by shallow to deep marine limestones, which range in age from Late Campanian to Early Eocene.  Geochemically, basaltic andesites and andesites display negative anomalies in Nb, Ta and Ti, enrichment in large ion lithophile elements (LILE) relative to high field strength elements (HFSE). Light rare earth elements (LREE) show slightly enrichment relative to heavy rare earth elements (La<sub>cn</sub>/Yb<sub>cn</sub> =2.51-3.63) and there are slight negative Eu anomalies (Eu/Eu* = 0.71-0.95) in basaltic andesite and andesite samples. The geochemical data indicate that Campanian volcanic rocks were derived from the partial melting of the mantle wedge induced by hydrous fluids released by dehydration of the subducted oceanic slab.</p><p>There is also a horizon of volcanic rocks, about 230 m thick, within the Late Campanian-Early Eocene limestone sequence.  This volcanic horizon, which consists of pillow basalts, porphyritic basalts,  andesites and dacites, is of Maastrichtian age based on paleontological data from the intra-pillow sediments and U-Pb zircon ages from the andesites and dacites (72-68 Ma).  The Maastrichtian andesites and dacites are geochemically distinct from the Campanian volcanic rocks. They show distinct adakite-like geochemical signatures with high ratios of Sr/Y (>85.5), high La<sub>cn</sub>/Yb<sub>cn </sub>(16.4-23.7) ratios, low content of Y (7.4-8.6 ppm) and low content of heavy rare-earth elements (HREE). The adakitic rocks most probably formed as a result of partial melting of the subducting oceanic slab under garnet and amphibole stable conditions.</p><p>The Upper Cretaceous arc sequence in the Kefken region shows a change from typical subduction-related magmas to adakitic ones, accompanied by decrease in the volcanism.</p><p> </p><p> </p>

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