scholarly journals Formation of the Granodiorite-Hosting Magushan Cu–Mo Polymetallic Deposit in Southern Anhui, Eastern China: Evidences from Geochronology and Geochemistry

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 475 ◽  
Author(s):  
Qi ◽  
Lu ◽  
Yang ◽  
Zhou ◽  
Zhao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Eastern China ◽  
Heavy Rare Earth Element ◽  
Quartz Veins ◽  
Polymetallic Deposit ◽  
High K ◽  
Icp Ms ◽  
Primary Type ◽  
T Values ◽  
Light Rare Earth Elements

The newly discovered Magushan Cu-Mo polymetallic deposit, located in southeastern Anhui, eastern China, is a middle-scale skarn-type polymetallic deposit with different ore types of veinlets-disseminated skarn (the primary type), quartz veins, and porphyry. LA-ICP-MS zircon U–Pb analyses yielded a crystallization age of 135.7 ± 1.5 Ma for the ore-related granodiorite in Magushan. The granodiorites are I-type granites in nature, characterized by metaluminous and high-K calc-alkaline characteristics. They are enriched in large ion lithophile elements (LILEs, e.g., Ba, Th, and U) and light rare earth elements (LREEs), and depleted in high field strength elements (NFSEs, e.g., Nb, Ta, and Ti) and heavy rare earth element (HREEs), with slightly negative Eu anomalies (Eu/Eu* = 0.81–0.86). These granodiorites show high Mg# (mainly > 40) values, high MgO (1.73–1.96 wt. %) and low Na2O (<4.21 wt. %) contents, with whole-rock (87Sr/86Sr)i ratios (0.708877 to 0.710398), negative εNd(t) values of −5.4 to −5.2, and negative zircon εHf(t) values of −4.60 to −1.37, with old two-stage Hf model ages (TDM2) between 1.2‒1.5 Ga. Besides, they are characterized by high radiogenic Pb isotopic compositions with (206Pb/204Pb)i = 18.44–18.56, (207Pb/204Pb)i = 15.66–15.67, and (208Pb/204Pb)i = 38.77–38.87. These granodiorites are characterized by high zircon Ce4+/Ce3+ ratios (average 893) and Eu/Eu* ratios (average 0.51), indicating high magmatic oxygen fugacities. The distinct geochemical and isotopic features suggest that the Magushan granodiorites could be formed by metasomatized mantle-derived magmas, mixing with materials from Neoproterozoic crust that is widely distributed in the Southern Anhui. This study concludes that the formation of the Magushan Cu-Mo polymetallic deposits may largely depend on an oxidizing environment and multi-sources mixed of mantle- and crust-derived materials.

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.

A model involving amphibolite lower crust melting and subsequent melt extraction for leucogranite generation

2021 ◽  
Author(s):  
Liqiang Wang ◽  
Wenbin Cheng ◽  
Teng Gao ◽  
Yong Wang
Keyword(s):  
Rare Earth ◽  
Partial Melting ◽  
Lower Crust ◽  
Melt Extraction ◽  
Southern Tibetan Plateau ◽  
Himalayan Orogenic Belt ◽  
Positive Correlations ◽  
Charge And Radius ◽  
T Values ◽  
Light Rare Earth Elements

In the southern Tibetan Plateau, leucogranites are dominantly distributed in the Himalayan orogenic belt with minor occurrences in the southern Lhasa subterrane. In this paper, we report the first Miocene Anglonggangri leucogranites in the northern Lhasa subterrane. This finding provides important constraints on both leucogranite petrogenesis and the tectono-magmatic evolution of the Lhasa terrane. The Anglonggangri leucogranites include biotite-muscovite granite and slightly younger garnet-muscovite granite and pegmatite. Zircon U-Pb and muscovite 40Ar-39Ar dating of these leucogranites yields Miocene ages of 11.1−10.2 Ma. The biotite-muscovite and garnet-muscovite granites are characterized by high SiO2 (72.3−74.4 wt%) and Al2O3 contents (14.4−15.4 wt%) and are peraluminous. The biotite-muscovite granite displays geochemical signatures with high Sr/Y (29.2−81.0) and (La/Yb)N (37.5−98.9) ratios, low Y (4.30−7.22 ppm) and Yb contents (0.26−0.47 ppm), low to moderate initial (87Sr/86Sr)i ratios (0.7085−0.7192), and moderate εNd(t) values (−10.17 to −6.94). Furthermore, they also exhibit radiogenic Pb isotope and variable zircon εHf(t) values (−9.6 to +4.4) with Proterozoic Nd (1.1−1.4 Ga) and Hf model ages (0.8−1.7 Ga). By comparison, the garnet-muscovite granite has lower CaO, MgO, TiO2, and total FeO contents and is enriched in Rb (380−466 ppm) and depleted in Sr (24.1−38.5 ppm) and Ba (30.7−58.6 ppm) and further characterized by a significant rare earth element (REE) tetrad effect and non-charge and radius-controlled (CHARAC) trace element behaviors. The garnet-muscovite granite shows a negative Eu anomaly and positive correlations among Sr and Eu, Sr and Ba, and Th and light rare earth elements (LREEs). Pegmatite comprising Nb-Ta oxides and cassiterite occurs in the garnet-muscovite granite. Geochronological and geochemical characteristics of the Anglonggangri leucogranites indicate that the magma of the biotite-muscovite granite was derived from partial melting of amphibolite lower crust contaminated with Proterozoic-Archean upper crustal materials. The garnet-muscovite granite was generated through melt extraction from the biotite-muscovite granite crystal mush. These results confirm that partial melting of the amphibolite lower crust not only occurred in the southern and central Lhasa subterranes but also in the northern Lhasa subterrane.

Age and composition of the Rushan intrusive complex in the northern Sulu orogen, eastern China: petrogenesis and lithospheric mantle evolution

2008 ◽  
Vol 146 (2) ◽  
pp. 199-215 ◽  
Author(s):  
HUA-YUN TANG ◽  
JIAN-PING ZHENG ◽  
CHUN-MEI YU
Keyword(s):  
North China Craton ◽  
North China ◽  
Eastern China ◽  
Major Elements ◽  
Intrusive Complex ◽  
Mantle Evolution ◽  
The North ◽  
High K ◽  
Cratonic Mantle ◽  
Light Rare Earth Elements

AbstractZircon U–Pb age, whole-rock elemental and Sr–Nd isotopic data are presented for the Rushan intrusive complex from the northern Sulu orogen, China. The intrusion, emplaced at c. 111 Ma, consists mainly of biotite-bearing gabbro and pyroxene-bearing diorite. The rocks are high-K calc-alkaline in major elements, and enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE), depleted in high field strength elements (HFSE), and possess narrow ranges of initial 87Sr/86Sr (0.70746–0.70827) and ɛNd(t) (−12.37 to −8.26). The complex is interpreted to originate from decompression melting of spinel-facies cratonic mantle that was metasomatized by the subducted Yangtze crustal materials and the melts experienced fractionation of olivine, clinopyroxene, apatite and Fe–Ti oxides. The Rushan complex is similar in composition to other Early Cretaceous mafic-intermediate complexes from the southern margin of the North China Craton, such as the Fangcheng basalts and Yinan gabbros, implying the mantle source of the Rushan intrusion is tectonically affiliated to the southern wedge of the Craton. We infer that the Rushan complex formed in an extensional regime corresponding to the asthenosphere upwelling during gradual erosion and replacement of the cratonic mantle by the fertile lithosphere beneath the eastern North China Craton.

The Mesozoic granitic magmatism in Haliheiba: implications from geochronology, geochemistry and Hf isotopes

2020 ◽  
Author(s):  
Wei Wei ◽  
Xiyong Wu
Keyword(s):  
North China ◽  
Hf Isotopes ◽  
Primitive Mantle ◽  
Crustal Accretion ◽  
The North ◽  
Icp Ms ◽  
Granitic Magmatism ◽  
Quartz Monzonite ◽  
T Values ◽  
Light Rare Earth Elements

&lt;p&gt;The Mesozoic granitic magmatism in Haliheiba is poorly understood because of lacking systematic data. Hence, this paper presents petrological observations, zircon U&amp;#8211;Pb ages, geochemistry and Hf isotopes for these rocks. These rocks comprise granidiorite and quartz monzonite. Zircon LA-ICP-MS U&amp;#8211;Pb dating yields emplacement ages of 247.6 &amp;#177; 1.1 Ma and 247.0 &amp;#177; 1.5 Ma for granidiorite and quartz monzonite, respectively. Geochemically, the granidiorite has SiO&lt;sub&gt;2&lt;/sub&gt; contents of 65.86&amp;#8211;67.37 wt% and alkali concentrations of 7.97&amp;#8211;8.44 wt%; the quartz monzonite has SiO&lt;sub&gt;2&lt;/sub&gt; contents of 66.95&amp;#8211;67.28 wt% and alkali concentrations of 8.52&amp;#8211;8.63 wt%, which belong to calc-alkaline series and are metaluminous rocks. These granitoids are enriched in light rare earth elements (LREEs) with (La/Yb)&lt;sub&gt;N&lt;/sub&gt; values from 5.27 to 12.09 and have slightly to moderately negative Eu anomalies with &amp;#948;Eu values from 0.53 to 0.78 in the chondrite-normalized REE diagram. Furthermore, these granitoids are relatively enriched Rb, U, Th, K, and Pb and slightly depleted in Nb, Ta, Ba, Ti, and P in the primitive mantle-normalized spider diagram. The above geochemical signatures reveal that these granites have I-type affinity. Zircon Hf isotope data show that these granitoids possess high positive &amp;#949;Hf(t) values from +8.9 to +14.9 and fairly young Hf model ages from 305 to 620 Ma, indicating that they are mainly derived from partial melting of juvenile crustal components. Combined with regional geology, our results indicate that the Triassic magmatism in Haliheiba most likely resulted from the subduction of the Paleo-Asian Ocean beneath the North China Craton. Our results together with regional isotopic data suggest that a significant crustal accretion event occurred during the Neoproterozoic to Paleozoic in the Great Xing&amp;#8217;an Range.&lt;/p&gt;

scholarly journals Petrogenesis and Tectonic Setting of the Highly Fractionated Junye Granitic Intrusion in the Yiliu Tungsten Polymetallic Deposit, Guangdong Province, South China: Constraints from Geochemistry and Sr-Nd-Pb-Hf Isotopes

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 631
Author(s):  
Tao Wu ◽  
Zhilong Huang ◽  
Mu Yang ◽  
Dexian Zhang ◽  
Jiawei Zhang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
South China ◽  
Tectonic Setting ◽  
Granitic Magma ◽  
Geochemical Data ◽  
Metallogenic Province ◽  
Polymetallic Deposit ◽  
South Central ◽  
High K

The Yiliu tungsten polymetallic deposit, located in the south central portion of the Nanling nonferrous metal metallogenic province in South China, is an area with common Yanshanian tectonothermal events. Early Yanshanian magmatism leads to the emplacement of voluminous tungsten-bearing granite intrusions, such as the Baoshan, Benggangling and Junye plutons, which are considered temporally and spatially associated with W-polymetallic mineralization in the Yiliu region. Here, we investigate the basic geological and petrological characteristics of the Junye granites, and present major and trace element geochemical data and bulk-rock Sr-Nd-Pb-Hf isotopic data to gain insight into the petrogenesis and tectonic setting of granitic intrusions in the region. The Junye granites are high-K calc-alkaline and metaluminous to weakly peraluminous [A/CNK = molar ratios of Al2O3/(CaO + Na2O + K2O) = 0.97–1.02] with enrichment in SiO2 (75.68–76.44 wt.%), relatively high total alkalis (K2O + Na2O = 8.06–8.45 wt.%) with K2O/Na2O ratios ranging from 1.12 to 1.42, and moderate Al2O3 (12.62–13.00 wt.%), but low in P2O5 (<0.01 wt.%), MgO (0.02–0.04 wt.%), CaO (0.78–0.95 wt.%) and Fe2O3T (0.93–1.07 wt.%). They show spectacular tetrad effect REE (rare earth element) patterns with low ΣREE content (53.2–145.3 ppm), negative Eu anomalies (δEu = 0.09–0.17) and slight enrichment of LREEs (light rare earth elements) relative to HREEs (heavy rare earth elements). The granites are enriched in Rb (481–860 ppm), Th (16.2–46.1 ppm) and U (25.4–40.8 ppm) but depleted in Ba (1.0–5.8 ppm), Sr (11.1–23.4 ppm), P (9.5–26.7 ppm) and Ti (241–393 ppm). All geochemical features lead us to interpret the Junye granites as highly fractionated I-type granites. These granites underwent intense interaction between highly evolved magma and volatile-rich hydrothermal fluids during the late stage of formation, and accompanied fractional crystallization of biotite, plagioclase and accessory minerals, such as apatite, monazite and allanite. Additionally, the granites show uniform Nd isotopic ratios with calculated εNd (152 Ma) values of −8.28 to −8.91 and Nd model age (TDM2) of 1645 to 1698 Ma, stable age-corrected initial Pb isotopic compositions with (206Pb/204Pb)i of 18.646–19.010, (207Pb/204Pb)i of 15.767–15.786 and (208Pb/204Pb)i of 39.113–39.159, respectively, and homogeneous Hf isotopic values yielding εHf (152 Ma) values from −6.9 to −9.5 with TDM2 ages of 1680 to 2214 Ma, collectively suggesting that the granitic magma was probably derived from the remelting of ancient infracrustal materials in the basement of the Nanling region. Consequently, we consider that the Junye granites are the products of partial melting of Paleoproterozoic infracrustal medium- to high-K metamorphic basaltic rocks in the Cathaysia Block, which was caused by the underplating of coeval mantle basaltic magmas that provided abundant heat energy for melting in a tectonic setting, with lithospheric extension and thinning during the late Jurassic period.

Precise magnesium isotope analyses of high-K and low-Mg rocks by MC-ICP-MS

2019 ◽  
Vol 34 (5) ◽  
pp. 940-953 ◽  
Author(s):  
Zhian Bao ◽  
Kangjun Huang ◽  
Tianzheng Huang ◽  
Bing Shen ◽  
Chunlei Zong ◽  
...  
Keyword(s):  
Igneous Rock ◽  
Magnesium Isotope ◽  
Rock Samples ◽  
High K ◽  
Icp Ms ◽  
Isotope Analyses

This study presents a chemical protocol for the separation of Mg that is particularly adapted for diverse igneous rock samples, especially for high-K and low-Mg rocks.

Rare-earth crystal chemistry of thalénite-(Y) from different environments

2018 ◽  
Vol 82 (2) ◽  
pp. 313-327
Author(s):  
Markus B. Raschke ◽  
Evan J. D. Anderson ◽  
Jason Van Fosson ◽  
Julien M. Allaz ◽  
Joseph R. Smyth ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Spatial Scales ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Element ◽  
X Ray ◽  
Golden Horn

ABSTRACTThalénite-(Y), ideally Y3Si3O10F, is a heavy-rare-earth-rich silicate phase occurring in granite pegmatites that may help to illustrate rare-earth element (REE) chemistry and behaviour in natural systems. The crystal structure and mineral chemistry of thalénite-(Y) were analysed by electron microprobe analysis, X-ray diffraction and micro-Raman spectroscopy from a new locality in the peralkaline granite of the Golden Horn batholith, Okanogan County, Washington State, USA, in comparison with new analyses from the White Cloud pegmatite in the Pikes Peak batholith, Colorado, USA. The Golden Horn thalénite-(Y) occurs as late-stage sub-millimetre euhedral bladed transparent crystals in small miarolitic cavities in an arfvedsonite-bearing biotite granite. It exhibits growth zoning with distinct heavy-rare-earth element (HREE) vs. light-rare-earth element (LREE) enriched zones. The White Cloud thalénite-(Y) occurs in two distinct anhedral and botryoidal crystal habits of mostly homogenous composition. In addition, minor secondary thalénite-(Y) is recognized by its distinct Yb-rich composition (up to 0.8 atoms per formula unit (apfu) Yb). Single-crystal X-ray diffraction analysis and structure refinement reveals Y-site ordering with preferential HREE occupation of Y2 vs. Y1 and Y3 REE sites. Chondrite normalization shows continuous enrichment of HREE in White Cloud thalénite-(Y), in contrast to Golden Horn thalénite-(Y) with a slight depletion of the heaviest REE (Tm, Yb and Lu). The results suggest a hydrothermal origin of the Golden Horn miarolitic thalénite-(Y), compared to a combination of both primary magmatic followed by hydrothermal processes responsible for the multiple generations over a range of spatial scales in White Cloud thalénite-(Y).

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