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1
Yu, Xue Feng, Da Peng Li, Hong Kui Li, Shu Xing Wang, and Wei Shan. "Mesozoic Tectonomagmatic Evolution and Gold Metallogeny in Jiaodong Area, East China." Advanced Materials Research 905 (April 2014): 92–95. http://dx.doi.org/10.4028/www.scientific.net/amr.905.92.
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There were twice major collision orogenic events in Jiaodong area in Mesozoic period. It showed as three times of magmatic activities and stretching in Jiaodong area. In this paper, based on collecting age datas, referring to the previous classification scheme, a chronological frame pattern of Yanshanian granites had been put forward: Linglong-Kunyushan granite emplacement was in in 160~150Ma; the formation of Guojialing granodiorite was in 130~126Ma; Weideshan granodiorite-granite emplacement was in 120~110Ma; Laoshan A-type miarolitic cavity parlkaline alkali feldspar granite emplacement was in 110~100Ma and represented the end of Yanshan movement. Gold mineralization in three periods in this area had coupled relation with Linglong-Kunyushan granite, Guojialing granodiorite and Weideshan granodiorite-granite. Jiaodong tectonic-magmatic events and gold mineralization were controlled by the interactions among Tethyan tectonic domain, Paleo-ocean tectonic domain and the Pacific tectonic domain.
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Xiong, Yi-Qu, Yong-Jun Shao, Yanbo Cheng, and Shao-Yong Jiang. "Discrete Jurassic and Cretaceous Mineralization Events at the Xiangdong W(-Sn) Deposit, Nanling Range, South China." Economic Geology 115, no. 2 (March 1, 2020): 385–413. http://dx.doi.org/10.5382/econgeo.4704.
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Abstract The Xiangdong W(-Sn) deposit is hosted in the Dengfuxian multiphase granites (biotite, two-mica, and muscovite granites) within the Nanling Range metallogenic belt in south China. Previous studies suggested that the W(-Sn) mineralization in the Xiangdong deposit is related to the Late Jurassic two-mica granite, whereas recently W-Sn–bearing quartz veins have also been identified in muscovite granite. We present new cassiterite and zircon U-Pb ages to constrain the timing of W-Sn mineralization and related granitic magmatism. Our laser ablation-inductively coupled plasma-mass spectrometry U-Pb dating of zircon grains, combined with previous zircon ages, in addition to the trace element composition of the muscovite granite, suggest the muscovite granite in the Dengfuxian pluton was emplaced at 145 to 142 Ma and shows highly evolved features. Cassiterite grains from the ore-bearing veins in two-mica granite yielded U-Pb ages of 151.6 ± 3.7 and 141 to 138 Ma, whereas cassiterite grains from quartz veins occurring in muscovite granite yielded a U-Pb age of 136.8 ± 3.3 Ma. The new ages and detailed geologic evidence indicate that the Early Cretaceous muscovite granite is also genetically related to W-Sn mineralization. Combining this with previously published data from the Late Jurassic two-mica granites and related mineralization, we suggest that there were two stages of W-Sn mineralization at Xiangdong. Arsenopyrite geothermometry from the two stages suggests temperatures of 300° to 491° and 308° to 450°C in stage I and stage II, respectively. Wolframite grains from the two stages also show different characteristics and patterns for their major and trace elements. The enrichment in Sc in wolframite suggests low-pH and low-Eh conditions for a fluid containing F– and/or PO43− complexes during stage I, whereas higher contents of Nb and Ta and lower contents of Sc in wolframite from stage II indicate relatively lower pH and higher Eh conditions. In combination with data from other recent studies, we propose that the 145 to 130 Ma interval represents a newly recognized W-Sn metallogenic period linked with highly evolved granites in the Nanling Range metallogenic belt. The Early Cretaceous muscovite granite is an important new target for W and Sn resources in south China.
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He, Zhilei, Zhende Zhu, Nan Wu, Zhen Wang, and Shi Cheng. "Study on Time-Dependent Behavior of Granite and the Creep Model Based on Fractional Derivative Approach Considering Temperature." Mathematical Problems in Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/8572040.
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Based on mineral components and the creep experimental studies of Three Gorges granite and Beishan granite from different regions of China at various temperatures, the strength and creep property of two types of granites are compared and analyzed. Considering the damage evolution process, a new creep constitutive model is proposed to describe the creep property of granite at different temperatures based on fractional derivative. The parameters of the new creep model are determined on the basis of the experimental results of the two granites. In addition, a sensitivity study is carried out, showing effects of stress level, fractional derivative order, and the exponentm. The results indicate that the proposed creep model can describe the three creep stages of granite at different temperatures and contribute to further research on the creep property of granite.
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Zan, Pei, Shouyu Chen, Jinduo Chen, and Shengli Li. "Early Paleozoic Adakitic Granitoids from the Xingshuping Gold Deposit of East Qinling, China: Petrogenesis and Tectonic Significance." Minerals 11, no. 10 (September 23, 2021): 1032. http://dx.doi.org/10.3390/min11101032.
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This study discussed the pertrological classification, geochronology, petrogenesis and tectonic evolution of early Paleozoic granites from the Xingshuping gold deposit in the East Qinling orogenic belt. In order to achieve this target, we carried out an integrated study of zircon U–Pb age, whole-rock major and trace elements, as well as Sr–Nd–Hf isotope compositions for the Xingshuping granites (part of the Wuduoshan pluton) from the Erlangping unit. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating constrains the emplacement age of the Xingshuping granites at 446.2 ± 1.2 Ma. The rocks at Xingshuping can be divided into two types: mainly biotite granite and monzonitic granite. The biotite granites are typical adakitic rocks, while the monzonitic granites show characteristics similar to normal arc volcanic rocks. The geochemical compositions reveal that they were derived from a clay-rich, plagioclase-rich and biotite-rich psammitic lower continental crust source, with contributions of mantle-derived magmas. The distinction is that the biotite granites were primarily derived from partial melting in a syn-collision extension setting, whereas the monzonitic granite went through a fractional crystallization process in an intraplate anorogenic setting.
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Dai, Hongzhang, Denghong Wang, Xin Li, Shanbao Liu, Chenghui Wang, and Yan Sun. "Genesis of the Wuzhutang Granite and Associated W–Sn–Be Mineralization in the Xuebaoding Mining Area, Sichuan Province, China." Minerals 12, no. 8 (August 5, 2022): 993. http://dx.doi.org/10.3390/min12080993.
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The Xuebaoding W–Sn–Be mining area, located in the Songpan–Garze orogenic belt in western China, is known for producing large, colorful, euhedral crystals of scheelite, cassiterite, and tabular beryl. Zircon LA-ICP-MS U–Pb dating of the Wuzhutang granite yields a concordia age of 218.96 ± 2.1 Ma, and a weighted mean 206Pb/238U age of 218.98 ± 1.12 Ma. Cassiterite LA-MC-ICPMS dating of the quartz vein bearing beryl, cassiterite, and scheelite, yields a concordant age of 213.5 ± 1.7 Ma. These observations indicate that magmatic activities and mineralization on the western side of the Zibaishan dome occurred during the late Indosinian, prior to their occurrence on the eastern side of the dome, reflecting the fact that the granite may have undergone two epochs of magmatic evolution and metallogenic processes. Geochemical analysis revealed that the Wuzhutang granite has relatively high A/CNK (average: 1.05) and differentiation index (DI; 81.16~85.88) values, and that they are enriched in W, Sn, Be, Li, and Cs. Unlike the Pukouling and Pankou granites, the Wuzhutang granite contains a certain amount of plagioclase and relatively high contents of Ba (633~1007 ppm) and Sr (334~411 ppm). Sr–Nd–Pb isotope values (87Sr/86Sr(t) = 0.70747–0.70865, εNd(t) = −6.35 to –4.34, 206Pb/204Pb = 18.186–18.3, 207Pb/204Pb = 15.556–15.592, and 208Pb/204Pb = 38.268–38.432) indicate a Mesoproterozoic basement origin for the Wuzhutang granite. We suggest the three granites belong to a peraluminous magma system and were derived by partial melting of the upper crust, the magma of the Wuzhutang granite originated from a deeper source and exhibits a lower degree of differentiation than that of the Pankou and Pukouling granites.
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XU, XI-SHENG, KAZUHIRO SUZUKI, LEI LIU, and DE-ZI WANG. "Petrogenesis and tectonic implications of Late Mesozoic granites in the NE Yangtze Block, China: further insights from the Jiuhuashan–Qingyang complex." Geological Magazine 147, no. 2 (October 27, 2009): 219–32. http://dx.doi.org/10.1017/s0016756809990367.
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AbstractThe Jiuhuashan–Qingyang complex is one of the Mesozoic granite complexes in the NE Yangzte Block, China. New petrographical and petrochemical data show that the complex comprises a dominant granodiorite–monzogranite, the Qingyang body, which was intruded by the Jiuhuashan granite body. The two are characterized by distinct mineral components and trace element patterns. Compared to the Qingyang granodiorite and monzogranite, the Jiuhuashan granite is enriched in Rb, Th, U, Nb, Ta, Hf, Yb and Lu, and depleted in Ba, Sr, Nd, Sm, Eu, Gd and Ti, which are ascribable to the separation of plagioclase and biotite, and crystallization of thorite and fergusonite during the magmatism. New LA-ICPMS zircon U–Pb dating suggests that the crystallization age of the Qingyang body is 139–133 Ma, and the Jiuhuashan granite followed at 127 Ma. Moreover, the new zircon U–Pb dates reveal that Archaean materials were involved in the formation of these magmas, and that a sodium-rich metasomatic event occurred at about 100 Ma. The CHIME monazite and zircon ages studied for the Jiuhuashan body agree well with the LA-ICPMS zircon ages. Integrating this information with previous studies for granites in the NE Yangtze Block and in the coastal area of SE China, we believe that all of these Late Mesozoic granites were produced under the tectonic regime of palaeo-Pacific plate subduction towards the SE China continent in a NW direction, but the granites in the NE Yangtze Block are basically derived by crustal melting with limited mixing of juvenile material during the magma generation.
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Yu, Zhi-Feng, Qi-Ming Peng, Zheng Zhao, Ping-An Wang, Ying Xia, Yu-Qi Wang, and Hao Wang. "Geochronology, Geochemistry, and Geodynamic Relationship of the Mafic Dykes and Granites in the Qianlishan Complex, South China." Minerals 10, no. 12 (November 29, 2020): 1069. http://dx.doi.org/10.3390/min10121069.
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The Qianlishan complex, located in Hunan Province of South China, is closely associated with intense W-dominated polymetallic mineralization. The Qianlishan complex is composed of three phases: the main-phase porphyritic and equigranular granites, granite porphyry, and mafic dykes. Geochronologically, the zircon U-Pb dating results show that the porphyritic and equigranular granites have ages of approximately 159 and 158 Ma, respectively, similar to those of mafic dykes (approximately 158 Ma), while the granite porphyry was formed later at approximately 145 Ma. Geochemically, the mafic dykes are characterized by calc-alkaline high-Mg andesite (HMA) with high MgO, TiO2, Mg#, and CA/TH index. They exhibit significantly depleted εNd(t) and εHf(t) with high Ba/La, La/Nb, and (La/Yb)N, indicating that they formed from mixing melts of depleted asthenospheric mantle and metasomatized subcontinental lithospheric mantle (SCLM). The main-phase granites are peraluminous and are characterized by high SiO2, low (La/Yb)N ratios, and relative depletion in Ba, Sr, Ti, and Eu. They also display negative correlations between La, Ce, Y, and Rb contents, suggesting that they are highly fractionated S-type granites. Furthermore, they show high εNd(t) and εHf(t), CaO/Na2O ratios, HREE, and Y contents, indicating that they were produced by parental melting of ancient basement mixed with mantle-derived components. In contrast, the granite porphyry shows A-type signature granites, with higher εNd(t) and εHf(t) and CaO/Na2O ratios than the main-phase granites but similar Zr/Nb and Zr/Hf ratios to the mafic dykes, suggesting that they are the products of partial melting of a hybrid source with ancient basement and the mafic dykes. We thus infer that the slab roll-back led to generation of Qianlishan back-arc basalt and HMA and further triggered the formation of the Qianlishan granite.
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Leng, Jiahao, Yulong Lu, Xingqiang Li, Xiangying Zhao, and Yang Liu. "Tungsten–Gold Metallogenetic Potential of the Ziyunshan Pluton in Central Hunan, South China: Insights from Element Geochemistry of Granites." Minerals 13, no. 2 (January 18, 2023): 144. http://dx.doi.org/10.3390/min13020144.
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In order to reveal the metallogenic potential of the Indosinian Ziyunshan granite in central Hunan, the temporal, spatial and genetic relationship between the mineralization and the granite is discussed, and the concentrations of ore-forming elements for different granites are measured. The geochemistry of the elements, isotope geochemistry and chronology, and the data derived from the analysis on Au-W deposit in the area are compared with the geologic features of the regional metallogenic rock. The results indicate that Ziyunshan granite is an irregular shaped complex of late Indosinian by multi-stage intrusion. Elements such as W, Sn, Cu, Pb, Ag, Sb, Be, Li and Ta are enriched in the granite. The sulfophilic elements including Au, Pb, Zn and Ag are relatively enriched in the main body of the Ziyunshan granite, while the lithophilic elements including W and Sn are relatively enriched in the late phase of the Ziyunshan granite. The zoning of the ore-forming elements could be observed in the granite: Nb and Ta (inside the granite); W, Sn, Mo and Bi (inner contact zone); Pb, Zn and Cu (contact zone); and Au and Sb (outer contact zone). All the deposits in the area are formed after the intrusion of the Ziyunshan granite except the Ni-Ta-Sn ore formed simultaneously with the Ziyunshan granite. The Ziyunshan granite provides necessary heat, active fluid and partial ore-forming materials sources, which may show good metallogenic potential.
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Yin, Rong, Li Han, Xiao-Long Huang, Jie Li, Wu-Xian Li, and Lin-Li Chen. "Textural and chemical variations of micas as indicators for tungsten mineralization: Evidence from highly evolved granites in the Dahutang tungsten deposit, South China." American Mineralogist 104, no. 7 (July 1, 2019): 949–65. http://dx.doi.org/10.2138/am-2019-6796.
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Abstract The Dahutang tungsten deposit, located in the Yangtze Block, South China, is one of the largest tungsten deposits in the world. Tungsten mineralization is closely related to Mesozoic granitic plutons. A drill core through a pluton in the Dalingshang ore block in the Central segment of the Dahutang tungsten deposit shows that the pluton is characterized by multi-stage intrusive phases including biotite granite, muscovite granite, and Li-mica granite. The granites are strongly peraluminous and rich in P and F. Decreasing bulk-rock (La/Yb)N ratios and total rare earth element (ΣREE) concentrations from the biotite granite to muscovite granite and Li-mica granite suggest an evolution involving the fractional crystallization of plagioclase. Bulk-rock Li, Rb, Cs, P, Sn, Nb, and Ta contents increase with decreasing Zr/Hf and Nb/Ta ratios, denoting that the muscovite granite and Li-mica granite have experienced a higher degree of magmatic fractionation than the biotite granite. In addition, the muscovite and Li-mica granites show M-type lanthanide tetrad effect, which indicates hydrothermal alteration during the post-magmatic stage. The micas are classified as lithian biotite and muscovite in the biotite granite, muscovite in the muscovite granite, and Li-muscovite and lepidolite in the Li-mica granite. The Li, F, Rb, and Cs contents of micas increase, while FeOT, MgO, and TiO2 contents decrease with increasing degree of magmatic fractionation. Micas in the muscovite granite and Li-mica granite exhibit compositional zonation in which Si, Rb, F, Fe, and Li increase, and Al decreases gradually from core to mantle, consistent with magmatic differentiation. However, the outermost rim contains much lower contents of Si, Rb, F, Fe, and Li, and higher Al than the mantle domains due to metasomatism in the presence of fluids. The variability in W contents of the micas matches the variability in Li, F, Rb, and Cs contents, indicating that both the magmatic and hydrothermal evolutions were closely associated with W mineralization in the Dahutang deposit. The chemical zoning of muscovite and Li-micas not only traces the processes of W enrichment by magmatic differentiation and volatiles but also traces the leaching of W by the fluids. Therefore, micas are indicators not only for the magmatic–hydrothermal evolution of granite, but also for tungsten mineralization.
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Mughal, Muhammad Saleem, Chengjun Zhang, Amjad Hussain, Hafiz Ur Rehman, Dingding Du, Mirza Shahid Baig, Muhammad Basharat, Jingya Zhang, Qi Zheng, and Syed Asim Hussain. "Petrogenesis and Geochronology of Tianshui Granites from Western Qinling Orogen, Central China: Implications for Caledonian and Indosinian Orogenies on the Asian Plate." Minerals 10, no. 6 (June 2, 2020): 515. http://dx.doi.org/10.3390/min10060515.
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The precise timing, petrogenesis, and geodynamic significance of three granitoid bodies (Beidao granite, Caochuanpu granite, Yuanlongzhen granite, and the Roche type rock) of the Tianshui area in the Western Qinling Orogen, central China, are poorly constrained. We performed an integrated study of petrology, geochemistry, and zircon U-Pb dating to constrain their genesis and tectonic implication. Petrographic investigation of the granites shows that the rocks are mainly monzogranites. The Al saturation index (A/CNK versus SiO2) of the granitoid samples indicates meta-aluminous to peraluminous I-type granites. Their magmas were likely generated by the partial melting of igneous protoliths during the syn-collisional tectonic regime. Rare-earth-elements data further support their origin from a magma that was formed by the partial melting of lower continental crust. The Beidao, Caochuanpu, and Yuanlongzhen granites yielded U-Pb zircon weighted mean ages of 417 ± 5 Ma, 216 ± 3 Ma, and 219 ± 3 Ma, respectively. This study shows that the Beidao granite possibly formed in syn- to post-collision tectonic settings due to the subduction of the Proto-Tethys under the North China Block, and can be linked to the generally reported Caledonian orogeny (440–400 Ma) in the western segment of the North Qinling belt, whereas Yuanlongzhen and Caochuanpu granites can be linked to the widely known Indosinian orogeny (255–210 Ma). These granitoids formed due to the subduction of the oceanic lithospheres of the Proto-Tethyan Qinling and Paleo-Tethyan Qinling. The Roche type rock, tourmaline-rich, was possibly formed from the hydrothermal fluids as indicated by the higher concentrations of boron leftover during the late-stages of magmatic crystallization of the granites.
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Liu, Shiyu, Yuping Liu, Lin Ye, Chen Wei, Yi Cai, and Weihong Chen. "Genesis of Dulong Sn-Zn-In Polymetallic Deposit in Yunnan Province, South China: Insights from Cassiterite U-Pb Ages and Trace Element Compositions." Minerals 11, no. 2 (February 13, 2021): 199. http://dx.doi.org/10.3390/min11020199.
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The Dulong Sn-Zn-In polymetallic deposit in the Yunnan province, SW China, hosts a reserve of 5.0 Mt Zn, 0.4 Mt Sn, and 7 Kt In. It is one of the most important polymetallic tin ore districts in China. Granites at Dulong mining area include mainly the Laojunshan granite (third phase), which occurs as quartz porphyry or granite porphyry dikes in the Southern edge of the Laojunshan intrusive complex. Granites of phases one and two are intersected at drill holes at depth. There are three types of cassiterite mineralization developed in the deposit: cassiterite-magnetite ± sulfide ore (Cst I), cassiterite-sulfide ore (Cst II) within the proximal skarn in contact with the concealed granite (granites of phases one to two and three), and cassiterite-quartz vein ore (Cst III) near porphyritic granite. Field geology and petrographic studies indicate that acid neutralising muscovitization and pyroxene reactions were part of mechanisms for Sn precipitation resulting from fluid-rock interaction. In situ U–Pb dating of cassiterite samples from the ore stages of cassiterite-sulfide (Cst II) and Cassiterite-quartz vein (Cst III) yielded Tera-Wasserburg U–Pb lower intercept ages of 88.5 ± 2.1 Ma and 82.1 ± 6.3 Ma, respectively. The two mineralization ages are consistent with the emplacement age of the Laojunshan granite (75.9–92.9 Ma) within error, suggesting a close temporal link between Sn-Zn(-In) mineralization and granitic magmatism. LA-ICPMS trace element study of cassiterite indicates that tetravalent elements (such as Zr, Hf, Ti, U, W) are incorporated in cassiterite by direct substitution, and the trivalent element (Fe) is replaced by coupled substitution. CL image shows that the fluorescence signal of Cst I–II is greater than that of Cst III, which is caused by differences in contents of activating luminescence elements (Al, Ti, W, etc.) and quenching luminescence element (Fe). Elevated W and Fe but lowered Zr, Hf, Nb, and Ta concentrations of the three type cassiterites from the Dulong Sn-Zn-In polymetallic deposit are distinctly different from those of cassiterites in VMS/SEDEX tin deposits, but similar to those from granite-related tin deposits. From cassiterite-magnetite ± sulfide (Cst I), cassiterite-sulfide ore (Cst II), to cassiterite-quartz vein ore-stage (Cst III), high field strength elements (HFSEs: Zr, Nb, Ta, Hf) decrease. This fact combined with cassiterite crystallization ages, indicates that Cst I–II mainly related to concealed granite (Laojunshan granites of phases one and two) while Cst III is mainly related to porphyritic granite (Laojunshan granites of phase three).
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Chen, Xu, Chunhua Wen, Debao Meng, Bin Li, Biguang Jiang, and Jinning Qin. "Implications of Major and Trace Element Migration in Altered Granites for Hydrothermal Alteration and Granite-Related Uranium Mineralization in the Sanjiu Ore Field, South China." Minerals 12, no. 2 (January 25, 2022): 144. http://dx.doi.org/10.3390/min12020144.
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The recently discovered Sanjiu ore field (SJOF) is a granite-related uranium ore field located in the middle of Zhuguangshan (South China). The relationship between hydrothermal alteration of granite and uranium mineralization in the SJOF is crucial yet understudied. In this study, the major- and trace-element contents of granite samples (fresh granite, altered granite, and tectonites) with different uranium contents were analyzed by using X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma–mass spectrometry (ICP–MS). The analytical results show a relative increase in Si, S, Ca, Pb, Mo, and Sb content in altered granites and tectonites, relative to fresh granites. During the mineralization stage, the increase of the aforementioned elements is related to various hydrothermal alterations (e.g., silicification, carbonation, sulfation, etc.) and newly formed minerals (e.g., microfine crystalline quartz veins; calcite agglomerates or fine veins; and metal sulfides, such as pyrite). There is a concomitant relative decrease in Na, K, Al, Fe, Mg, and other elemental contents that may be due to mineralogical alteration processes, such as biotite to chlorite, feldspar-group minerals to clay minerals, and redox of Fe-bearing minerals. The LREE/HREE ratio in altered granites decreases significantly with the increase in uranium content, suggesting that a low LREE/HREE ratio may be a prospecting indicator. The normalized trace-element patterns of mineralized granite (ore) and the relatively high U content of fresh granite imply that granitic rocks may be the primary uranium source in the SJOF. The uranium mineralization is mainly concentrated in the redox zone that occurs at a depth of 100−300 m. The redox zone is characterized by the most developed hydrothermal alterations and enrichment of trace elements, including W, Mo, Sb, Li, and the HREE.
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Belkasmi, M., M. Cuney, P. J. Pollard, and A. Bastoul. "Chemistry of the Ta-Nb-Sn-W oxide minerals from the Yichun rare metal granite (SE China): genetic implications and comparison with Moroccan and French Hercynian examples." Mineralogical Magazine 64, no. 3 (June 2000): 507–23. http://dx.doi.org/10.1180/002646100549391.
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AbstractIn the Yichun granite complex (SE China), columbite group minerals, microlite and cassiterite are the main Nb, Ta, Sn-bearing minerals. They are mainly concentrated in the uppermost albite-lepidolite granite. Rutile is the only Nb, Ta-bearing phase in the geochemically primitive muscovite-zinnwaldite granite. The chemical evolution of the columbite group minerals (the most abundant and commonly zoned Nb, Ta-bearing minerals) indicates a complex crystallization history of the host granites with: (1) fractional crystallization at depth, reflected by a strong increase of Mn/(Mn+Fe) ratios with a moderate increase of Ta/(Ta+Nb) ratios from the muscovite-zinnwaldite granite to the Li-mica granite and then the most fractionated topaz-lepidolite granite; and (2) emplacement of successive magma batches corresponding to the different units of the granite complex with progressive crystallization of each unit, mainly reflected by a strong increase of Ta/(Ta+Nb) ratios with moderate variation of Mn/(Mn+Fe) ratios during the growth of the zoned crystals. The data are compared with those from the RMG of Ezzirari (Morocco), Montebras, Beauvoir and Chèdeville (France).
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Huo, Hailong, Da Zhang, Zhengle Chen, Yongjun Di, Xiaolong He, Ning Li, and Bojie Hu. "Geochemistry and Zircon U–Pb Geochronology of the Zhuxi Granites in the Jingdezhen Area, Jiangxi Province, China: Implications for the Mesozoic Tectonic Development of South China." Minerals 12, no. 3 (February 24, 2022): 283. http://dx.doi.org/10.3390/min12030283.
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Mesozoic granitic magmatism in Northeastern Jiangxi, China is of tectonic significance for the evolution of the South China Block. Whole-rock geochemical and zircon U–Pb geochronological and Lu–Hf isotopic data for Mesozoic Zhuxi granites in the Jingdezhen area of Northeastern Jiangxi were presented. The Zhuxi granites are composed of granodiorite, biotite granite, and two-mica granite. Zircon LA–ICP–MS U–Pb isotopic analyses indicated emplacement at 159–147 Ma. The granites are characterized by a strongly peraluminous nature with high A/CNK values (>1.1), high SiO2 (66.09–74.46 wt.%) and K2O (3.50–5.52 wt.%) contents, depletion in Ba, Nb, Ce, Sr, and Ti, moderately negative Eu anomalies (Eu/Eu* = 0.40–0.63), enrichment in LREE, and depletion in HREE ((La/Yb)N > 7.43). The A/CNK > 1.1, widespread aluminum-rich minerals (e.g., muscovite and tourmaline), indicating they are S–type granites and belong to muscovite–bearing peraluminous granites (MPG). The Zhuxi granites exhibited negative εHf(t) values (−9.9 to −3.7) and the TDM2 model ages of 1840–1442 Ma indicated derivation from ancient crustal sources. The magma is possibly caused by the subsequent process of intracontinental subduction. It is inferred that the Mesozoic magmatism in Northeastern Jiangxi was associated with oceanic–continental convergence of the Paleo–Pacific and Eurasian plates as well as the intracontinental subduction of the Yangtze and Cathaysia blocks. The Zhuxi granites highlight the primary role of oceanic–continental convergence and intracontinental subduction in early Yanshanian granitoid magmatism in South China.
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CHEN, LING, CHANG-QIAN MA, ZHEN-BING SHE, ROGER MASON, JIN-YANG ZHANG, and CHAO ZHANG. "Petrogenesis and tectonic implications of A-type granites in the Dabie orogenic belt, China: geochronological and geochemical constraints." Geological Magazine 146, no. 5 (January 19, 2009): 638–51. http://dx.doi.org/10.1017/s0016756808005918.
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AbstractThe Dabie orogenic belt is characterized by the presence of large volumes of intrusive and volcanic rocks that formed in Late Mesozoic times. Most of the intrusive bodies are I-type granites but it is still unclear whether there are contemporary A-type granites. Here, we report the first unambiguous discovery of A-type granite from Baiyashan in the North Dabie tectonic belt. The crystallization age of the body has been fixed as 120.4 ± 1.2 Ma using U–Pb analysis of zircons by LA-ICPMS. The Baiyashan granite is enriched in Si, K, Na, Rb and REE, has elevated FeOtot/(FeOtot + MgO) and Ga/Al ratios, and is depleted in Mg, Ca, Mn, Ba, Sr, P and Ti. The REE composition shows highly fractionated patterns with (La/Yb)N = 6.95–16.68 and Eu*/Eu = 0.33–0.59. Its crystallization age, field relationships, petrographic and geochemical data show beyond doubt that the Baiyashan granite is an Early Cretaceous A-type granite. Sr–Nd isotope systematics are characterized by a high ISr of 0.708–0.714 and a low ɛNd of −7.5 to −19.4, with TDM2 = 1.5–2.5 Ga, and these data indicate that the magmas were dominantly sourced from partial melting of middle to lower crustal intermediate-felsic igneous rocks and mingling with mafic to intermediate magmas, during rift-related magmatism associated with subduction of the Palaeo-Pacific Plate beneath Eastern China in Early Cretaceous times.
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Tian, Mao-Jun, Huan Li, Landry Soh Tamehe, and Zhen Xi. "Geochronology and Geochemistry of the Zengudi and Tuobake Granite Porphyries in the Sanjiang Region, SW China: Petrogenesis and Tectonic Significance." Minerals 11, no. 4 (April 12, 2021): 404. http://dx.doi.org/10.3390/min11040404.
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The boundary between the Gondwana and Yangtze plate is still controversial. In southwest China, the Sanjiang region marks the collision zone which accreted several blocks coming from the northern Gondwana margin. In this region, subduction of the Paleo-Tethys Ocean and associated continental blocks during the Triassic Period led to the formation of an N–S trending complex involving intrusive and volcanic rocks. The intrusive rocks are important for constraining the evolution of the Paleo-Tethyan in southwestern China. This study presents new geochronological, geochemical, and Sr-Nd-Hf isotopic data of granite porphyries from northern Lancangjiang, in order to discuss the origin of these granites and their tectonic significance. Representative samples of the Zengudi and the Tuobake granite porphyries from the Yezhi area yielded weighted mean 206Pb/238U ages of 247–254 Ma and 246 Ma, respectively. The Zengudi granite porphyries display zircon ԐHf(t) values of −12.94 to −2.63, ԐNd(t) values of −14.5 to −9.35, and initial 87Sr/86Sr ratios of 0.708 to 0.716. The Tuobake granite porphyries have zircon ԐHf(t) values of −14.06 to −6.55, ԐNd(t) values of −10.9 to −9.41, and initial 87Sr/86Sr ratios of 0.716 to 0.731. Both the Zengudi and Tuobake granite porphyries exhibit strongly peraluminous signatures with high A/CNK nAl2O3/(K2O + Na2O + K2O) ratios (1.07–1.86 and 0.83–1.33, respectively). These granites are enriched in Rb and Th, and depleted in Ti, Nb, Ta, Sr, and P, with negative Eu anomalies (Eu/Eu* < 0.61). These geochemical and isotopic data indicate that the primary magma of the granite porphyries originated from partial melting of ancient continental crust as a result of basaltic magma underplating and underwent fractionation crystallization during their emplacement. We propose that the Triassic subduction of the Paleo-Tethys Ocean led to crust shortening and thickening in the Sanjiang region, while the northern Lancangjiang area was involved in the continental collision after the subduction of the Paleo-Tethys Ocean before 254 Ma.
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Lee, Byung Choon, Weon-Seo Kee, Uk Hwan Byun, and Sung Won Kim. "Statherian (ca. 1714–1680 Ma) Extension-Related Magmatism and Deformation in the Southwestern Korean Peninsula and Its Geological Significance: Constraints from the Petrological, Structural, Geochemical and Geochronological Studies of Newly Identified Granitoids." Minerals 11, no. 6 (May 24, 2021): 557. http://dx.doi.org/10.3390/min11060557.
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In this study, petrological, structural, geochemical, and geochronological analyses of the Statherian alkali feldspar granite and porphyritic alkali feldspar granite in the southwestern part of the Korean Peninsula were conducted to examine petrogenesis of the granitoids and their tectonic setting. Zircon U-Pb dating revealed that the two granites formed around 1.71 Ga and 1.70–1.68 Ga, respectively. The results of the geochemical analyses showed that both of the granites have a high content of K2O, Nb, Ta, and Y, as well as high FeOt/MgO and Ga/Al ratios. Both granites have alkali-calcic characteristics with a ferroan composition, indicating an A-type affinity. Zircon Lu-Hf isotopic compositions yielded negative εHf(t) values (−3.5 to −10.6), indicating a derivation from ancient crustal materials. Both granite types underwent ductile deformation and exhibited a dextral sense of shear with a minor extension component. Based on field relationships and zircon U-Pb dating, it was considered that the deformation event postdated the emplacement of the alkali feldspar granite and terminated soon after the emplacement of the porphyritic alkali feldspar granite in an extensional setting. These data indicated that there were extension-related magmatic activities accompanying ductile deformation in the southwestern part of the Korean Peninsula during 1.71–1.68 Ga. The Statherian extension-related events are well correlated with those in the midwestern part of the Korean and eastern parts of the North China Craton.
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Li, Ying Shu, Yan Cai, Jiao Jiao Chen, Nan Chen, Lun Wang, Yi Ke Zhang, and Da Qing He. "Geochemistrical Features of Laojunshan Granite and its Evolution in East-South Yunnan, China." Advanced Materials Research 634-638 (January 2013): 3375–79. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3375.
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Laojunshan granite is located in east-south Yunnan. Study on the geology, petrochemistry, microelement and rare earth elements of the Laojunshan granite indicates that the Laojunshan granite is a complex granite, which is divided into three epoch and various metasomatism within the granite is visible. The content of titanium, iron, magnesium is low and the content of silicon, aluminium, potassium is high in the granite, reflecting the granite is a granite of saturated-aluminium series and speculating mother rock of the granite is mud, psammitic rock. Formation of the granite is related with geological development of Laojunshan area, sedimenting in form of subside in the pre-Caledonian epoch, upheavaling in the late-Caledonian epoch and arising orogeny from the Indo-Chinese epoch to the Yannshan epoch, and undergoing sedimention, regional metamorphism, migmatization, granitization and remelting magma emplacement. Because Laojunshan granite possesses features of autochthonous and parautochthonous transformation type granite, origin of Laojunshan rock body belongs to continental crust alterational and metasomatic remelting granite.
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Liu, Xue Long, Wen Chang Li, Yan Yang, and Guang Hou Yin. "Tectonic Environment and Geochemical Characteristics of Geza Arc Magmatic Rocks in Sanjiang Orgenic Belt, SW China." Advanced Materials Research 734-737 (August 2013): 444–47. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.444.
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Geza island arc located in the southwest Sanjiang tectonic igneous rock belts, it was a products of Ganzi-Litang oceanic crust diving to Zhongdian Landmasses in late Triassic and a important of newly discovered copper polymetallic belts in the recent years in China. The regional strong tectonic-magmatic activity throughout the island-arc orogenesis from beginning to the end, the rich mineralization developed in the different times and different circumstances. Based on the development stage of island arc orogenic,the distribution of intrusive rocks, rocks composition, geochemical characteristics, Geza island arc granit belt can be divided into three belts. Lithogeochemical characteristics show that the porphyry (porphyrite) and island-arc granite rocks have the same rock series (high-K calc-alkaline) and the same genetic type (I-type granite); these rocks trace elements very similar to granite of island arc, which enriched in Ba, La, Hf, Au,chalcophile elements Cu,Pb, siderophile elements Mo, Ni, and depleted in Rb, Nb, P, Ti.
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Li, Longxue, Qingye Hou, Dingling Huang, and Xinyu Wang. "Early Permian Granitic Magmatism in Middle Part of the Northern Margin of the North China Craton: Petrogenesis, Source, and Tectonic Setting." Minerals 11, no. 2 (January 20, 2021): 99. http://dx.doi.org/10.3390/min11020099.
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The late Palaeozoic was an important period of tectonic evolution for the northern margin of the North China Craton (NCC). The source(s) and tectonic setting of early Permian granitoid rocks emplaced along the northern margin of the NCC are still unclear. These granitoids formed between ~295.4–276.1 Ma (uncertainties ranging from ±1.5 to ±7.8 Ma) according to zircon laser ablation inductively coupled mass spectrometry (LA-ICP-MS) and sensitive high-resolution ion microprobe (SHRIMP) U-Pb data. The Dadongou (DDG) pluton is an A1-type granite and the Dananfangzi (DNFZ) pluton is an A2-type granite. The Erdaowa (EDW), Lisicun (LSC), Wuhai (WH) and Gehuasitai (GHST) plutons are I-type granites. The Yuanbaoshan (YBS) dykes are diorite and syenodiorite. All the granitoids are enriched in large ion lithophile elements and light rare earth elements, depleted in high field strength elements and have negative εNd(t) and εHf(t) values. The A1-type granite was formed by the melting of the mafic crust. The A2-type granite was derived from partial melting of tonalite gneiss from the NCC crust and mantle materials. The EDW, LSC, WH and GHST granites mainly originated from partially melted granulite, with some mantle input. The YBS dykes are formed by the magma mixing of hot mantle melt and the relatively cold crustal magma. The northern margin of the NCC experienced anorogenic and collision tectonic stages, and the structural setting started to transform to post-collision at the later period of early Permian.
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Chen, Binghan, Jun Deng, and Xingzhong Ji. "Time Limit of Gold Mineralization in Muping–Rushan Belt, Eastern Jiaodong Peninsula, China: Evidence from Muscovite Ar–Ar Dating." Minerals 12, no. 3 (February 23, 2022): 278. http://dx.doi.org/10.3390/min12030278.
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Controversy surrounds the genetic relationship between gold mineralization and magmatism, especially in deposits in granite. Jiaodong Peninsula is the leading gold province in China, and most deposits are in Mesozoic granites; moreover, debate on the genesis persists. In eastern Jiaodong, the Muping–Rushan gold belt produces mainly quartz–sulfide vein-type gold, and the Upper Jurassic Kunyushan granite and Late Lower Cretaceous Sanfoshan granite are the wall rock. Precise mineralization ages should be identified to determine whether gold is related to the intrusion. In this study, three gold deposits (Sanjia, Yinggezhuang, and Xipo) from two ore-controlling faults were considered. Muscovites from quartz–sulfide veins and beresite were selected for Argon–Argon dating. The results obtained were 116.51 ± 0.47 Ma, 120.02 ± 0.38 Ma, and 121.65 ± 0.48 Ma for the three deposits, respectively. The mineralization lasted about 5 Ma in the Muping–Rushan gold belt. The test results showed that the mineralization was 16 Ma later than the intrusion time of Kunyushan granite and was earlier than that of Sanfoshan granite. Only the cooling age overlapped with the mineralization age. Previous studies have demonstrated that the ore fluid is of medium–low salinity and medium–low temperature. No typical high–low temperature mineral assemblage exists in the Muping–Rushan gold belt. Hence, gold deposits in Muping–Rushan gold belt could not be categorized as intrusion-related gold type.
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Wei, Hao, Jiuhua Xu, Guorui Zhang, Xihui Cheng, Haixia Chu, Chunjing Bian, and Zeyang Zhang. "Hydrothermal Metasomatism and Gold Mineralization of Porphyritic Granite in the Dongping Deposit, North Hebei, China: Evidence from Zircon Dating." Minerals 8, no. 9 (August 21, 2018): 363. http://dx.doi.org/10.3390/min8090363.
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A porphyritic granite intrusion was recently discovered in the Zhuanzhilian section of the Dongping gold deposit. There is as many as one tonnage of Au in the fractured shear zone within the porphyritic granite intrusion, but no relevant reports concerning the origin and age of the intrusion has been published as yet. In this paper, zircon U-Pb dating is used to study the geochronology of porphyritic granite, in order to find out the evidence of age and the relationship with gold mineralization. There are two groups of zircon 207Pb/235U-206Pb/238U concordant ages of porphyritic granites: The concordant age of 373.0 ± 3.5 Ma, with the weighted mean age of 373.0 ± 6.4 Ma; and the concordant age of 142.02 ± 1.2 Ma with the weighted mean age of 142.06 ± 0.84 Ma. We believe that the first group might represent the age of residual zircon of alkaline complex, while the second group might be related with main gold mineralization. The obtained results of the petrography and electron probe analysis indicate that the porphyritic quartz and porphyritic granite, as well as gold mineralization, might be products of a late replacement of tectonic-hydrothermal fluid, which was rich in Si, Na and K originally and later yielded gold-forming fluids.
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Bulakh, Andrey, Paavo Härmä, Elena Panova, and Olavi Selonen. "Rapakivi granite in the architecture of St Petersburg: a potential Global Heritage Stone from Finland and Russia." Geological Society, London, Special Publications 486, no. 1 (2020): 67–76. http://dx.doi.org/10.1144/sp486-2018-5.
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AbstractRapakivi granites were in use during the Middle Ages in Finland. Their most spectacular use, however, was for structures built in St Petersburg between 1760 and 1917. Remarkable examples are the majestic and slender Alexander Column and the 112 columns of St Isaac's Cathedral. All Rapakivi granite was extracted from the Wiborg Rapakivi granite batholith in several quarries around the municipality of Virolahti in SE Finland (old Russia). Today, the 1640 Ma-old Wiborg batholith is the most important area for natural stone production in Finland and in the Leningrad region, Russian Federation. The main quarried stone varieties of Rapakivi granite (Baltic Brown, Baltic Green, Carmen Red, Karelia Red, Eagle Red and Balmoral Red) are regularly produced in large quantities in Finland for the global stone market due to the stone's unique qualities. Examples of applications in Rapakivi granite from Finland can be found in the USA, China, South Africa, the UK, Italy, Austria, Ireland, Spain and Germany as well as in Scandinavia and Russia. There are also quarries near Vyborg, the Russian Federation: Vozrozhdenie and Ala-Noskua.
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Liu, Huimin, Zhaojun Song, Hongbo Yan, Wenyu Wang, Xinru Wang, Yifang Sun, and Haonan Li. "New View on the Genesis of the Bashuihe Pluton, Laoshan Granites, China: Indications from Fluid Inclusions and H–O Isotopes." Geofluids 2021 (February 6, 2021): 1–12. http://dx.doi.org/10.1155/2021/6655431.
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Oval caves have recently been discovered in the Bashuihe granite pluton of Laoshan Mountain, China. Oval caves typically occur in alkaline granites. This study conducted microthermometry and stable isotope analysis of quartz inclusions from oval caves and host rocks from the Bashuihe pluton to reconstruct the diagenetic evolutionary history of the Laoshan area. The temperature measurement results indicated a homogenisation temperature range from 162.5 to 261.6°C (mean 203.9°C), a salinity range of 2.1–8.3 wt% (mean 5.07 wt%), and a density range of 0.8–0.98 g/cm3 (mean 0.90 g/cm3), indicating a low-temperature, low-salinity, and low-density fluid. The emplacement depth ranged from 2.73 km to 4.43 km, indicating medium-shallow granite. A hydrogen and oxygen isotope analysis ( δ D = − 83.58 – − 67.17 , δ 18 O H 2 O = 0.83 – 0.39 ) revealed that the diagenetic fluids of the Bashuihe pluton represented a mixed hydrothermal solution composed of meteoric water and magmatic water. The results of a whole rock, H–O isotopes, rare earth element, and high field strength element analysis on the Laoshan alkali granites suggest significant hydrothermal activity in the late stage of magmatism. Primary oval caves in the Bashuihe pluton most likely evolved in the following sequence: fluid was enriched in the late diagenetic stage, diagenetic minerals crystallised under low temperature and pressure conditions, the crystallisation rate accelerated, and the magma condensed rapidly. Moreover, the increase in magma fluid enabled the movement and convergence of fluid. The accumulated fluid and volatiles occupied more space, and rapid magma condensation trapped the accumulated fluid and volatiles in the pluton, forming the oval granite cave. This research provides a crucial theoretical reference for the development and utilisation of underground space and engineering buildings in granite regions.
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Liu, Zekun. "Metallogenic characteristics and genesis of granite type uranium ore bodies in South China." E3S Web of Conferences 261 (2021): 02068. http://dx.doi.org/10.1051/e3sconf/202126102068.
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South China is the key producing area of granite-type uranium deposits in China. After decades of exploration, many important progress has been made in the study of metallogenic regularity of granite type uranium deposits in this area. On the basis of previous studies, this paper attempts to sort out the geological conditions and characteristics of diagenesis and mineralization of granite type uranium deposits in South China, and discuss their metallogenic models, so as to better summarize the metallogenic regularity and serve the prospecting and prediction.
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YU, SHENG-YAO, JIAN-XIN ZHANG, XI-LIN ZHAO, JIANG-HUA GONG, and YUN-SHUAI LI. "Geochronology, geochemistry and petrogenesis of the late Palaeoproterozoic A-type granites from the Dunhuang block, SE Tarim Craton, China: implications for the break-up of the Columbia supercontinent." Geological Magazine 151, no. 4 (September 19, 2013): 629–48. http://dx.doi.org/10.1017/s0016756813000538.
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AbstractThe discovery ofc. 1.77 Ga A-type granite in the Tarim Craton (TC) provides the first evidence that supports an extensional event related to fragmentation of the Columbia supercontinent in the late Palaeoproterozoic. We present laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb ages, Lu–Hf isotopic data and the whole-rock geochemical and Nd isotopic data of A-type granites in the Dunhuang area in the SE Tarim Craton. Zircon U–Pb dating for three granite samples indicate that they were emplaced atc. 1.77 Ga. Zircons from these granites have εHf(t) values ranging from –5.9 to 8.7, corresponding to two-stage model ages of 1.9–2.7 Ga. These granites exhibit the following petrological geochemical characteristics that are typical of A-type granite: (a) high content of SiO2and alkalis (i.e. high K2O + Na2O with K2O/Na2O > 1), enrichment of high-field-strength elements (HFSE) and rare Earth elements (REE) (except for Eu) and extreme depletion of Ba, Sr, P, Ti and Eu; (b) 10000×Ga/Al ratios in the Dunhuang granites of 3.5–4.4, with an average value of 3.79 which is similar to the global average of 3.75 for A-type granites; (c) the presence of characteristic minerals such as amphibole, sphene and perthite; and (d) zirconium saturation temperature results indicate that the Dunhuang granites have high initial magmatic temperatures in the range 887–950°C, similar to those of typical of A-type granites. Whole-rock εNd(t) values range from –2.5 to –6.2 andTDMmodel ages from 2.3 to 2.7 Ga. Nd–Hf isotopic and whole-rock geochemical data indicate that these granites were most likely derived from the late Archean crustal source in a post-collisional/post-orogenic extensional tectonic environment. The late Palaeoproterozoic A-type granites in the TC could be correlated with those of the North China Craton (NCC), India and the Canadian Shield, thus demonstrating extensional tectonics and break-up of the Columbia supercontinent.
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Sun, Xing Li, Xiao Huang Liu, Jiu Feng Liu, and Bai Nian Sun. "The Age and Origin of the Jinfosi Biotite Granite, North Qilian, NW China: Evidence from U–Pb Zircon Age Data, Geochemistry, and Nd–Sr–Pb Isotopes." Advanced Materials Research 616-618 (December 2012): 3–18. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.3.
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New geochemistry, Nd–Sr–Pb isotopes and U–Pb zircon data from the Jinfosi Biotite granite provide important constraints on the evolution of the crust in this part of the North Qilian, NW China. The Jinfosi Biotite granite have the following properties: SiO2 > 65%, A/CNK(Molar Al2O3/(CaO + Na2O + K2O) ratios generally > 1.1, Na2O generally < 3.2%, Sm/Nd values between 0.17 and 0.27, and high Rb/Sr values. A chondrite-normalized rare earth element (REE) pattern shows negative Eu anomalies and depletion in heavy REEs. 143Nd/144Nd values are relatively low, and values of εNd(t) and εSr(t) are indicative of continental lithosphere. (87Sr/86Sr)i values are between 0.69952 and 0.70962, corresponding to continental crust mixed with a minor component of mantle material. Values of 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb are 18.9–19.0, 15.59–15.85, and 38.00–and 39.00, respectively, corresponding to S-type collision-related granites. The Jinfosi Biotite granite yield a SHRIMP zircon U–Pb age of 416.7 ± 4.1 Ma. R1–R2 and Rb versus (Yb + Nb) discrimination diagrams indicate that the Jinfosi biotite granite was produced during continental collision following closure of the paleo-North Qilian Ocean.
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Qin, Yue, Yongfeng Cai, Wei Fu, Zhixuan Han, Panfeng Liu, Changling Lao, Yongshan Zhao, Zhengchao Han, and Yun Zhou. "Mineralogical, Geochronological, and Geochemical Characteristics of Early Cretaceous Granite in South China: Implications for Tectonic Evolution and REE Mineralization." Minerals 12, no. 10 (October 17, 2022): 1308. http://dx.doi.org/10.3390/min12101308.
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One of the most important geological features of South China are the widespread Mesozoic igneous rocks that play a key role in revealing the tectonic evolution of South China. Due to the thick covering of vegetation and Quaternary sediments, the early Cretaceous magmatism in southwestern South China is still not well constrained. In this paper, we report newly identified early Cretaceous granites in Guangxi, South China. Zircon U–Pb dating results showed that representative fine-grained and coarse-grained granites in northeastern Guangxi indicate the early Cretaceous ages of 141 ± 3 Ma and 141 ± 4 Ma, respectively. Geochemically, both fine-grained and coarse-grained granites had high 10,000 × Ga/Al ratios and belonged to A-type granite. They had undergone high degrees of magma differentiation, as evidenced by extremely negative Sr, Ba, and Eu anomalies. They had high REE (rare earth elements) contents (>451 ppm). The fine-grained granites were characterized by higher HREE (heavy rare earth elements) contents, lower LREE (light rare earth elements) contents, and lower LREE/HREE ratios than the coarse-grained granites. Integrated with regional geological data, the early Cretaceous granites were likely formed in a back-arc extensional environment in response to the increased subduction angle of the Paleo-Pacific plate. Different REE contents in the fine- and coarse-grained granites may be a result of fractional crystallization. Magma differentiation and hydrothermal alteration might have played an important role in REE mineralization of the early Cretaceous granites in Guangxi.
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DENG, XIN, KUNGUANG YANG, ALI POLAT, TIMOTHY M. KUSKY, and KAIBIN WU. "Zircon U–Pb ages, major and trace elements, and Hf isotope characteristics of the Tiantangzhai granites in the North Dabie orogen, Central China: tectonic implications." Geological Magazine 151, no. 5 (December 18, 2013): 916–37. http://dx.doi.org/10.1017/s0016756813000976.
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AbstractCretaceous granites are widespread in the North Dabie orogen, Central China, but their emplacement sequence and mechanism are poorly known. The Tiantangzhai Complex in the North Dabie Complex is the largest Cretaceous granitic suite consisting of six individual intrusions. In this study, zircon U–Pb ages are used to constrain the crystallization and protolith ages of these intrusions. The Shigujian granite is a syn-tectonic intrusion with an age of 141 Ma. This granite was emplaced under a compressional regime. Oscillatory rims of zircons have yielded two peaks at 137±1 Ma and 125±1 Ma. The 137±1 Ma peak represents the beginning of orogenic extension and tectonic collapse, whereas the 125±1 Ma peak represents widespread granitic magmatism. Zircon cores have yielded concordant ages between 812 and 804 Ma, which indicate a crystallization age for the protolith. The Tiantangzhai granites show relatively high Sr contents and high La/Yb and Sr/Y ratios. The Shigujian granite has positive Eu anomalies resulting from partial melting of a plagioclase-rich source in an over-thickened crust. Correspondingly, in situ Lu–Hf analyses from zircons yield high negative εHf(t) values from −24.8 to −26.6, with two-stage Hf model ages from 2748±34 to 2864±40 Ma, suggesting that the magmas were dominantly derived from partial melting of middle to lower crustal rocks. The Dabie orogen underwent pervasive NW–SE extension at the beginning of the early Cretaceous associated with subduction of the Palaeo-Pacific plate beneath eastern China.
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Wang, R. C., G. T. Zhao, J. J. Lu, X. M. Chen, S. J. Xu, and D. Z. Wang. "Chemistry of Hf-rich zircons from the Laoshan I- and A-type granites, Eastern China." Mineralogical Magazine 64, no. 5 (October 2000): 867–77. http://dx.doi.org/10.1180/002646100549850.
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AbstractZircon commonly occurs as one of important accessory HFSE-bearing minerals in A-type granite. A detailed electron microprobe study was carried out on zircon from the Laoshan complex, Eastern China, which is composed of I- and A-type granites. Zircon from the I-type rocks is relatively poor in trace elements (HfO2<2 wt.%, UO2, ThO2 and Y2O3 <1 wt.%), but that from the A-type rocks is richer in Hf, U, Th and Y. Hafnian zircon with a HfO2 content of up to 12.37 wt.% was found in the arfvedsonite granite, which is considered the most evolved facies in the A-type suite. Enrichment in Hf is generally observed at the rims of zircon crystals relative to the cores. The Hf enrichment in zircon, and the association of exotic REE- and HFSE-bearing minerals are linked to hydrothermal activity, suggesting that during the last stage of crystallization of the A-type magma, fluids enriched in REE, HFSE, F−, CO32− and PO43− were released.
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Pham, Minh, Hieu Trung Pham, and Hoang Kim Nguyen. "Geochemical characteristics of the Muong Hum alkaline granite in the Phan Si Pan zone, Northwestern Vietnam." Science and Technology Development Journal - Natural Sciences 1, T2 (June 30, 2017): 114–23. http://dx.doi.org/10.32508/stdjns.v1it2.451.
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Alkaline granites of the Muong Hum are distributed mainly in the NW Phan Si Pan zone. The granite closely has striped or clear gneissoid structures, coinciding with general NW-SE trends. It consists mainly of plagioclase (~20–30 %), alkaline feldspar (~30–50 %), quartz (~20–25 %), biotite (~1–5 %), aegirine (~1–3 %), and riebeckite (~1–2 %). It has 10,000×Ga/Al ratios of 4.70–4.93, A/CNK values of 0.87–0.90, and negative Eu-anomalies as well as apparent depletion of Ba, Sr, Ti, and P. The mineral assemblages and chemical characteristics show that it is typical of A-type granites. Compared with other adjacent Late Permian to Early Triassic A-type granitic plutons, geochemical characteristics of the Muong Hum granite are similar to the Phu Sa Phìn, Phan Si Pan, Ye Yen Sun, and Nam Xe-Tam Duong granites in NW Vietnam as well as the Taihe, and Panzhihua granites in SW China. Thus, the Phan Si Pan zone must have been a displaced portion of the Emeishan large igneous province. This might be a direct result of the left-lateral Cenozoic Red River shear zone.
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Xie, L., R. C. Wang, D. Z. Wang, and J. S. Qiu. "A survey of accessory mineral assemblages in peralkaline and more aluminous A-type granites of the southeast coastal area of China." Mineralogical Magazine 70, no. 6 (December 2006): 709–29. http://dx.doi.org/10.1180/0026461067060362.
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AbstractAn extensive belt of A-type granite exists along the southeast coast of China. The granites are divided into peralkaline and more aluminous subgroups which differ in mineral assemblages, mineral compositions and textures. In the peralkaline subgroup, primary magmatic Th-rich zircon is typically overgrown by Th-poor zircon containing thorite micro-inclusions. REE minerals in this subgroup are dominated by allanite-(Ce), chevkinite-(Ce), titanite and pyrochlore. Fe-Ti oxides are titanian magnetite and Mn-rich ilmenite. In contrast, in the more aluminous subgroup rocks, zircon is weakly zoned and exhibits very low Th but relatively high U contents. The REE minerals are dominated by Th-rich monazite-(Ce). Titanium-poor magnetite, pyrophanite and rutile are the major Fe-Ti oxides. These occurrences indicate that peralkaline magmas favour the formation of REE silicates, whereas magmas with higher alumina saturation stabilize REE phosphates. Peralkaline granites crystallized at temperatures 50–100°C greater than the more aluminous granites, but under lower oxidation conditions. These differences in formation conditions of the two A-type granite subgroups, deduced by accessory mineralcharacteristics, are inferred to be related to magma derivation at different crustal levels, with peralkaline magma deriving from a deeper crustal level with more mantle input.
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Liu, Jun, You Fei Guan, Yong Zhan, and Hai Jiao You. "The Thermal History of the Hukeng Granite Body in Jiangxi Province, South China." Applied Mechanics and Materials 170-173 (May 2012): 928–31. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.928.
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The Hukeng granite body locates in southeast limb of Wugongshan compound anticline, where developed large scale tungsten deposit that is an important part of poly-metallic metallogenetic belt in South China. The thermal history of the Hukeng granite has been studied based on zircon U-Pb dating, whole rock Rb-Sr dating and K-Ar dating of muscovite from the same rock body. From the beginning of zircon crystallization to the closure of whole rock Rb-Sr system, the Hukeng granite body had a relatively fast cooling rate (65°C/Ma), and from the closure of whole rock Rb-Sr system to the closure of K-Ar system of muscovite, the granite body had a very fast cooling rate (208.3°C/Ma). The Hukeng granite body had a very short cooling period (<5Ma) and experienced a rapid cooling process.
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Zhang, Liang, Roberto F. Weinberg, Li-Qiang Yang, David I. Groves, Sheng-Xun Sai, Erin Matchan, David Phillips, et al. "Mesozoic Orogenic Gold Mineralization in the Jiaodong Peninsula, China: A Focused Event at 120 ± 2 Ma During Cooling of Pregold Granite Intrusions." Economic Geology 115, no. 2 (March 1, 2020): 415–41. http://dx.doi.org/10.5382/econgeo.4716.
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Abstract Jiaodong gold deposits are mainly sited along faulted contacts between Upper Jurassic Linglong granite and Precambrian basement metamorphic rocks or Lower Cretaceous Guojialing granite. Long-standing controversies relate to timing of gold mineralization and granite-gold relationships. In this study, gold-related muscovite consistently provides concordant 40Ar/39Ar plateau ages of 120 ± 2 Ma (2σ) for the Jiaojia, Sizhuang, and Luoshan deposits. Analogous 40Ar/39Ar timing constraints from gold-related muscovite are provided by total gas and high-temperature ages from Fushan, concordant high-temperature ages from Rushan, and fusion-step ages from Xiadian deposits. These new 40Ar/39Ar ages, when combined with previous reliable 40Ar/39Ar and U-Pb age constraints for mineralization, including ages of pre- and postgold dikes, define a widespread gold mineralization event at 120 ± 2 Ma (2σ). Published zircon U-Pb ages for Guojialing and Aishan granite magmatism suggest an ~8-m.y. lag between peak intrusive activity and gold mineralization. This, together with lack of both high-temperature alteration assemblages and alteration and/or metal zonation, indicates that the structurally controlled Jiaodong deposits are orogenic rather than intrusion-related deposits. Despite this, granite intrusions are considered to have provided suitable fluid trap sites. New 40Ar/39Ar analyses of biotite from the Linglong and Guojialing granites show they had cooled to about ~300° ± 50°C by ca. 123 to 124 Ma, providing pressure-temperature conditions similar to those under which most orogenic gold deposits formed close to the ductile-brittle transition. This enabled the effective ingress of fluids at supralithostatic pressures at 120 ± 2 Ma, leading to intensive brecciation, alteration, and deposition of both vein-type and disseminated gold ores. New zircon (U-Th)/He dates together with apatite fission-track data indicate that preservation of the gold province is due to slow postmineralization uplift and exhumation.
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Zhang, Yaoyao, Kai Liu, Ye Wang, Da Zhang, Xuanxue Mo, Yuefei Deng, Tingxi Yu, and Zenan Zhao. "Geological Significance of Late Permian Magmatic Rocks in the Middle Section of the Ailaoshan Orogenic Belt, SW China: Constraints from Petrology, Geochemistry and Geochronology." Minerals 12, no. 5 (May 21, 2022): 652. http://dx.doi.org/10.3390/min12050652.
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The Ailaoshan orogenic belt, located in the SE margin of the Qinghai–Tibet Plateau, is an important Paleo-Tethys suture zone in the eastern margin of the Sanjiang Tethys tectonic domain. The areas of Mojiang and Zhenyuan, located in the middle part of the Ailaoshan orogenic belt, are the key parts of the Ailaoshan Paleo-Tethys Ocean closure and collision orogeny. The rhyolites outcropped in the Mojiang area, and the granite porphyries outcropped in Zhenyuan area, are systematically studied for petrology, isotope geochemistry and geochronology. The Zircon U-Pb geochronology of rhyolites and granite porphyries give weighted average ages of 253.4 ± 4.2 Ma and 253.3 ± 2.0 Ma, respectively, both of which were formed in the late Permian period. The rhyolites belong to potassic calc-alkaline to subalkaline series. The patterns of the rare earth elements (REE) show a right-inclined seagull-type distribution, and the trace elements plot is right-inclined. The granite porphyries are high potassic calc-alkaline to subalkaline. The REE patterns show a right-inclined distribution, and the trace elements plot is right-inclined, which is consistent with the typical patterns observed in the crust. The peraluminous, highly differentiated and high ASI values suggest that rhyolites and granite porphyries are S-type granites. The zircon εHf(t) of the rhyolites range from −7.22 to −0.72, and two-stage Hf zircon model ages are (TDMC) 1771–2352 Ma, indicating that the magma source area is mainly crust-derived. The zircon εHf(t) of the granite porphyries range from −0.97 to 4.08, and two-stage Hf zircon model ages are (TDMC) 1336–1795 Ma, indicating that the magma is derived from a depleted mantle source and the partial melting of ancient crustal materials. The rhyolites and granite porphyries were possibly formed in the syn-collisional tectonic setting during the late Permian, and their ages limited the time of the final closure of the Ailaoshan Ocean and the initiation of collisional orogeny.
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Xie, Guiqing, Jingwen Mao, Wei Li, Bin Fu, and Zhiyuan Zhang. "Granite-related Yangjiashan tungsten deposit, southern China." Mineralium Deposita 54, no. 1 (April 12, 2018): 67–80. http://dx.doi.org/10.1007/s00126-018-0805-5.
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Liu, Jun, Zhen Xiu Liao, Ying Chen, Yong Zhan, and You Fei Guan. "Sr-Nd-Pb Isotopic Geochemistry of the Hukeng Granite Body in Jiangxi Province, South China." Applied Mechanics and Materials 353-356 (August 2013): 1187–90. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.1187.
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The Mesozoic Hukeng granite body locates in southeast limb of Wugongshan compound anticline in Jiangxi Province, South China. This study uses samples from the Hukeng granite body to determine the characteristics of Sr-Nd-Pb isotopes and source of the granite body. The rocks have 87Sr/86Sr ratios as high as 0.84112, suggesting that crustal contamination existed there. The rocks have higher ratios of 87Rb/86Sr, 87Sr/86Sr and (87Sr/86Sr)i, and lower ratios of 147Sm/144Nd, 43Nd/144Nd and lower εNd(t), indicating that the Hukeng granite body possessesEMⅡ-like characteristics. Combined with Pb isotopic values (206Pb/204Pb ratios from 18.5313 to 18.8460, 207Pb/204Pb ratios from 15.6562 to 15.6782 and 208Pb/204Pb ratios from 38.7015 to 38.7565), the Hukeng granite body originated from EMⅡ and suffered crustal contamination in certain extent.
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Wang, Juntao, Lingwei Kong, Junbiao Yan, and Zhenhua Zhou. "Comparative Investigation on Small-Strain Stiffness Characteristics of Undisturbed and Compacted Highly Weathered Granites at Various Densities." Geofluids 2022 (October 22, 2022): 1–17. http://dx.doi.org/10.1155/2022/3935815.
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To investigate the small-strain stiffness characteristics of highly weathered granite (HWG), a resonance column test system was used to conduct resonance column tests on highly weathered granite taken from the Lincang City, Yunnan Province, China. The effects of effective consolidation stress and structural changes is caused by remodeling process and initial dry density on the small-strain stiffness of HWG. Furthermore, the difference between the test data and other geotechnical materials were compared and analyzed. The test results show that the maximum dynamic shear modulus G max of remodeled highly weathered granite samples is greater than that of undisturbed samples once the effective consolidation stress is smaller than 300 kPa, but the opposite result is observed once the effective consolidation stress exceeds 300 kPa, and the phenomenon was also explained from a microscopic perspective based on the scanning electron microscopy (SEM). The G max of remodeled highly weathered granite gradually increases with the increase in dry density and effective consolidation stress. At an identical effective consolidation stress, the dynamic shear modulus ratio G / G max − γ curves of remodeled highly weathered granites at different initial dry densities are nearly consistent. Additionally, according to the test data, the mathematical model of G max for remodeled highly weathered granite considering effective consolidation pressure and initial dry density was established and agrees well with the test results of practical engineering cases. The range of variation in G / G max was given by the research results, which were compared with the G / G max of weathered granite obtained from the existing research, and the results in this work can provide a valuable reference for analyzing dynamic stability of buildings in the engineering construction of weathered granite sites.
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Charoy, Bernard, and Pierre Barbey. "Ferromagnesian silicate association in S-type granites: the Darongshan granitic complex (Guangxi, South China)." Bulletin de la Société Géologique de France 179, no. 1 (January 1, 2008): 13–27. http://dx.doi.org/10.2113/gssgfbull.179.1.13.
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Abstract The late Indosinian Darongshan granite complex (Guangxi Province, South China) consists mainly of three plutons (Taima, Jiuzhou and Darongshan), with coarse-grained to subvolcanic rock types. There is a rough mineral evolution from the western to the eastern part of the complex, with ferromagnesian magmatic silicates sequentially distributed : Opx+Crd±Bt (Taima), Opx+Grt+Bt+Crd (Jiuzhou) and Bt+Crd (Darongshan). Restitic, cumulative or xenocrystic minerals (mainly Crd with fibrolite+spinel inclusions, Grt and probably Opx in some cases) are also encountered. Mineralogical, chemical and isotopic compositions of the granites suggest that the three plutons derive from a source dominated by a reduced, immature greywacke-psammite series, which has experienced high-amphibolite to granulite-facies metamorphism. This S-type granite complex is considered to result from various degrees of melting at different crustal levels by biotite dehydration-melting in a high T (800° to 950°C), low P (400–600 MPa) metamorphic environment. Abundant granulite-facies metasedimentary enclaves with refractory compositions are considered as xenoliths entrapped during magma ascent. The presence of scarce mafic microgranular enclaves and the high temperatures needed for melting could suggest that heat may have been partly contributed by mantle-derived magmas.
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ZENG, QING-DONG, JIN-HUI YANG, JIAN-MING LIU, SHAO-XIONG CHU, XIAO-XIA DUAN, ZUO-LUN ZHANG, WEI-QING ZHANG, and SONG ZHANG. "Genesis of the Chehugou Mo-bearing granitic complex on the northern margin of the North China Craton: geochemistry, zircon U–Pb age and Sr–Nd–Pb isotopes." Geological Magazine 149, no. 5 (November 24, 2011): 753–67. http://dx.doi.org/10.1017/s0016756811000987.
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AbstractThe Chehugou granite-hosted molybdenum deposit is typical of the Xilamulun metallogenic belt, which is an important Mo–Ag–Pb–Zn producer in China. A combination of major and trace element, Sr and Nd isotope, and zircon U–Pb isotopic data are reported for the Chehugou batholith to constrain its petrogenesis and Mo mineralization. The zircon SIMS U–Pb dating yields mean ages of 384.7 ± 4.0 Ma and 373.1 ± 5.9 Ma for monzogranite and syenogranite and 265.6 ± 3.5 Ma and 245.1 ± 4.4 Ma for syenogranite porphyry and granite porphyry, respectively. The Devonian granites are calc-alkaline with K2O/Na2O ratios of 0.44–0.52, the Permian granites are alkali-calcic with K2O/Na2O ratios of 1.13–1.25, and the Triassic granites are calc-alkaline and alkali-calcic rocks with K2O/Na2O ratios of 0.78–1.63. They are all enriched in large-ion lithophile elements (LILEs) and depleted in high-field-strength elements (HFSEs) with negative Nb and Ta anomalies in primitive mantle-normalized trace element diagrams. They have relatively high Sr (189–1256 ppm) and low Y (3.87–5.43 ppm) concentrations. The Devonian granites have relatively high initial Sr isotope ratios of 0.7100–0.7126, negative ɛNd(t) values of −12.3 to −12.4 and 206Pb/204Pb ratios of 16.46–17.50. In contrast, the Permian and Triassic granitoids have relatively low initial 87Sr/86Sr ratios (0.7048–0.7074), negative ɛNd(t) values of −10.1 to −13.1 and 206Pb/204Pb ratios of 17.23–17.51. These geochemical features suggest that the Devonian, Permian and Triassic Chehugou granitoids were derived from ancient, garnet-bearing crustal rocks related to subduction of the Palaeo-Asian Ocean and subsequent continent–continent collision between the North China and Siberian plates.
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Elton, N. J., J. J. Hooper, and L. Coggon. "Morinite from Gunheath China Clay Pit, St Austell, Cornwall." Mineralogical Magazine 60, no. 400 (June 1996): 517–18. http://dx.doi.org/10.1180/minmag.1996.060.400.14.
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Morinite, NaCa2A12(PO4)2(OH)F4.2H2O, is a lowtemperature hydrothermal phosphate found in granite and granite-pegmatite environments. It was first described by Lacroix in 1891 from Montebras, France (see Palache et al., 1951) where it occurred as rose coloured prismatic crystals with amblygonite, wardite, wavellite, apatite and cassiterite. Morinite is also known from Germany, Finland (Roberts et al., 1990) and the USA (Fisher and Runner, 1958; Fisher, 1960).
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Miao, Jin Xiang, Cai Xia Li, Jin Qu, Xin Chen, Hong Wang, and Qin Chang Song. "3D Geological Modeling (Deposit Scale) for Granite Rock-Mass in Yuku Area, Luanchuan, China." Advanced Materials Research 962-965 (June 2014): 92–98. http://dx.doi.org/10.4028/www.scientific.net/amr.962-965.92.
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In order to find out the spatial shape of a granite rock-mass, three kinds of data can be used:1) The exploration data (drilling data, geological profile data, geological boundaries and so on); 2) The ridge extension line data applied to speculate the concealed granite rock-mass based on low magnetic-anomaly zone (△T≤50nT) from high-precision magnetic-prospecting and Controlled-Source Audio-Frequency Magnetotelluric (CSAMT) results; 3) The other interpolated data of concealed granite rock-mass boundary on CSAMT comprehensive prospecting profile. With these data, a simulating 3D model of the granite rock-mass can be established to provide basic data for prospecting deep concealed porphyry-polymetallic ore deposits.
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Ding, Kun, Xiuqing Yang, Hui Wang, Ying Li, Kai Liu, Zhihui Wang, Liang Zhao, and Yanjun Chen. "Geochronology and Geochemistry of the Granite Porphyry from the Qinglingou Gold Deposit, South Qinling, China: Implication for Petrogenesis and Mineralization." Minerals 12, no. 6 (May 31, 2022): 707. http://dx.doi.org/10.3390/min12060707.
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The Zhashui-Shanyang ore cluster area is one of the most important gold polymetallic ones in northwestern China. The Qinglingou gold deposit is a newly discovered small-scale deposit in the Zhashui-Shanyang area. Gold mineralization closely related to acid intrusive rocks has been found for the first time in this area. In this paper, the geochronology, whole-rock geochemistry, and isotope signature of the granite porphyries in the deposit are studied. They are characterized by variable medium SiO2 (67.22–71.72 wt.%), high K2O + Na2O contents (6.54–10.34 wt.%), and variable Al2O3 (14.47–15.10 wt.%) values. The A/CNK ratios range from 0.90 to 1.23, and the A/NK ratios vary from 1.14 to 1.48. These rocks also contain biotite and amphiboles and are similar to peraluminous and high-K calc-alkaline I-type granites. The Qinglingou granite porphyries show relative enrichment of Rb, Th, and K, and depletion of Nb, Ta, P, Ti, and other high field strength elements. These porphyries are enriched in light rare earth elements relative to heavy rare earth elements with weak negative Eu anomalies (δEu = 0.63–0.89), which is interpreted to be the best age of crystallization of the Qinglingou porphyries. LA–ICPMS zircon U–Pb dating yields an age of 211 ± 1.2 Ma (n=16, MSWD=0.39). The close spatial relationship between the ore bodies and granite porphyry dikes indicates that this age may represent the metallogenic age in this area. The zircons have 176Hf/177Hf ratios ranging from 0.282625 to 0.282702, the εHf(t) values are near 0 and the two-stage zircon Hf model ages range from 1121 to 1296 Ma. These data indicate that the Qinglingou granite porphyries were derived from the interplay between mantle- and crustal-derived magmas. We therefore propose that there is potential gold in carbonate rocks at the periphery of porphyry-skarn copper-molybdenum deposits.
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ZHAO, XILIN, YANG JIANG, GUANGFU XING, ZHIHONG CHEN, KAI LIU, MINGGANG YU, and SHENGYAO YU. "A geochemical and geochronological study of the Early Cretaceous, extension-related Honggong ferroan (A-type) granite in southwestern Zhejiang Province, southeast China." Geological Magazine 155, no. 3 (September 27, 2016): 549–67. http://dx.doi.org/10.1017/s0016756816000790.
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AbstractThe Honggong pluton is the largest ferroan alkalic (A-type) granite intrusion emplaced along the Jiangshan–Shaoxing fault zone in southwestern Zhejiang Province, and has important implications for understanding the Late Mesozoic tectonic evolution of SE China. U–Pb ages of 138.7 ± 0.8, 134.2 ± 1.1, 128.5 ± 1.5 and 126.1 ± 0.9 Ma were obtained from zircon by laser ablation–inductively coupled plasma–mass spectrometry, indicating that the Honggong pluton formed in the Early Cretaceous. The Honggong pluton has a clear ferroan alkalic (A-type) granite geochemical signature with, for example, high total alkali contents and FeOt/(FeOt+ MgO) values. The Sr–Nd–Hf isotopic compositions suggest that there was juvenile material in the magma source. Geochemical evidence indicates that the pluton was derived through extensive fractionation of melts that contained both asthenospheric mantle and Mesoproterozoic crustal components. These rare granites in southern China were emplaced during five episodes at 235–225, 190, 165–155, 100–90 and 140–120 Ma. The age of the Honggong pluton suggests that localized extension in southwestern Zhejiang Province began as early as ~138 Ma and continued to 126 Ma. This Early Cretaceous extensional event was triggered by localized rollback of the subducting Pacific Plate.
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Yang, Wu, Min Zhang, Jun Yan, and Xiaocui Chen. "Zircon U-Pb Ages and Geochemistry of the Granite in the Xintianling Tungsten Deposit, SE China: Implications for Geodynamic Settings of the Regional Tungsten Mineralization." Minerals 12, no. 8 (July 28, 2022): 952. http://dx.doi.org/10.3390/min12080952.
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The Xintianling tungsten deposit is a super-large deposit in the Nanling tungsten–tin mineralization belt, which is genetically associated with the early-stage hornblende-biotite monzonitic granite of Qitianling pluton. The orebodies predominantly occur as veins and lenses within skarn rocks between Xintianling granite and limestone (Shidengzi group). In this work, whole-rock major and trace elements and zircon U–Pb ages of the Xintianling granite were studied in an attempt to investigate the geochronological framework, petrogenesis, tectonism, and metallogenesis with regard to the deposit. The petrographic and geochemical analyses indicated that the Xintianling granite consists of three intrusive units of medium- and coarse-grained biotite granite, fine-grained biotite granite, and granite porphyry, of which the biotite granite was strongly associated with mineralization. Biotite granite rocks are highly K-calc-alkaline and weakly peraluminous, with A/CNK ratios ranging from 0.99 to 1.05. Late-granite porphyry is aluminum-supersaturated with a high evolution degree, whose geochemical characteristics suggest that it is either an I- or S-type granite. LA-ICP-MS zircon U-Pb dating revealed that medium- and coarse-grained biotite granite (162.3 ± 1.2 Ma, MSWD = 1.3), fine-grained biotite granite (161.8 ± 1.3 Ma, MSWD = 1.8), and granite porphyry (154.3 ± 1.6 Ma, MSWD = 2.4) formed in the late Jurassic. The emplacement of the Qitianling A-type granite and associated tungsten-tin polymetallic mineralization is a continuous evolution process, and they are products of the large-scale mineralization of the Nanling in the middle–late Jurassic (150–160 Ma). Under the tectonic setting of the Mesozoic lithospheric extension, asthenosphere upwelling along deep-fault, intensive mantle–crust interaction processes probably provide not only the high heat flow, but also partly mantle-derived material for large-scale W-Sn-polymetallic mineralization in this area.
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Zhu, Xinxiang, Markus B. Raschke, and Yan Liu. "Tourmaline as a Recorder of Ore-Forming Processes in the Xuebaoding W-Sn-Be Deposit, Sichuan Province, China: Evidence from the Chemical Composition of Tourmaline." Minerals 10, no. 5 (May 14, 2020): 438. http://dx.doi.org/10.3390/min10050438.
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The Xuebaoding W-Sn-Be deposit located in the Songpan-Ganze Orogenic Belt (Sichuan Province, China) is a hydrothermal deposit with less developed pegmatite stage. The deposit is famous for the coarse-grained crystals of beryl, scheelite, cassiterite, apatite, fluorite, muscovite, and others. The orebody is spatially associated with the Pankou and Pukouling granites hosted in Triassic marbles and schists. The highly fractionated granites are peraluminous, Li-Rb-Cs-rich, and related to W-Sn-Be mineralization. The mineralization can chiefly be classified based on the wallrock and mineral assemblages as muscovite and beryl in granite (Zone I), then beryl, cassiterite and muscovite at the transition from granite to triassic strata (Zone II), and the main mineralized veins composed of an assemblage of beryl, cassiterite, scheelite, fluorite, and apatite hosted in metasedimentary rock units of marble and schist (Zone III). Due to the stability of tourmaline over a wide range of temperature and pressure conditions, its compositional variability can reflect the evolution of the ore-forming fluids. Tourmaline is an important gangue mineral in the Xuebaoding deposit and occurs in the late-magmatic to early-hydrothermal stage, and can thus be used as a proxy for the fluid evolution. Three types of tourmalines can be distinguished: tourmaline disseminations within the granite (type I), tourmaline clusters at the margin of the granite (type II), and tourmalines occurring in the mineralized veins (type III). Based on their chemical composition, both type I and II tourmalines belong to the alkali group and to the dravite-schorl solid solution. Type III tourmaline which is higher in X-site vacancy corresponds to foitite and schorl. It is proposed that the weakly zoned type I tourmalines result from an immiscible boron-rich aqueous fluid in the latest stage of granite crystallization, that the type II tourmalines showing skeletal texture directly formed from the undercooled melts, and that type III tourmalines occurring in the mineralized veins formed directly from the magmatic hydrothermal fluids. Both type I and type II tourmalines show similar compositional variations reflecting the highly fractionated Pankou and Pukouling granites. The higher Ca, Mg, and Fe contents of type III tourmaline are buffered by the composition of the metasedimentary host rocks. The decreasing Na content (<0.8 atoms per formula unit (apfu)) and increasing Fe3+/Fe2+ ratios of all tourmaline samples suggest that they precipitated from oxidized, low-salinity fluids. The decreasing trend of Al content from type I (5.60–6.36 apfu) and type II (6.01–6.43 apfu) to type III (5.58–5.87 apfu) tourmalines, and associated decrease in Na, may be caused by the crystallization of albite and muscovite. The combined petrographic, mineralogical, and chemical characteristics of the three types of tourmalines thus reflect the late-magmatic to early-hydrothermal evolution of the ore-forming fluids, and could be used as a geochemical fingerprint for prospecting W-Sn-Be mineralization in the Xuebaoding district.
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He, Miao, Qing Liu, Quanlin Hou, Jinfeng Sun, and Quanren Yan. "Petrogenesis of the Microgranular Enclaves and Their Host Granites from the Xitian Intrusion in South China: Implications for Geodynamic Setting and Mineralization." Minerals 10, no. 12 (November 26, 2020): 1059. http://dx.doi.org/10.3390/min10121059.
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The South China Block had experienced a significant tectonic transition during the Mesozoic in response to the subduction of the Paleo- and the Pacific Ocean. Large-scale granitic intrusions with massive mineralization are widespread in South China, and their tectonic settings are not defined. The Xitian intrusion is ideal for probing the geodynamic setting and mineralization in South China because they comprise an abundance of microgranular enclaves (MEs) and diverse types of granite associated with mineralization. Age determined by zircon U-Pb dating suggests that the MEs and their host granites are coeval within error, of ca. 152 Ma. The MEs have a similar initial Hf-O isotopic composition as host granites, and the rapid cooling mineral textures indicate that they are autoliths. Geochemical data show that the host granites are high-K, calc-alkaline, and transitional from metaluminous to peraluminous, slightly enriched in light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs), with obvious negative Eu anomalies, belonging to I-type. The Nb/Ta and Zr/Hf ratios indicate the volatile penetrates the magmatic-forming process, and the fluid with abundant volatile could extract metal element effectively from the mantle.
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Li, Yang, Yongqiang Yang, Lei Hua, Yaxing Leng, and Jiang Xin. "Geochronology and Tectonic Implications of the Nianzigou Granites and Associated Mo Deposit, Inner Mongolia." Minerals 12, no. 7 (June 21, 2022): 791. http://dx.doi.org/10.3390/min12070791.
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Multiple stages of igneous rocks occur in the recently discovered Nianzigou Mo deposit in Chifeng, Inner Mongolia, which can provide insights into the late Mesozoic geodynamic evolution of the southern Da Hinggan Range. The mineralization age is similar to the age of local granites, but there are few detailed studies of the tectonic setting during Cu-Mo mineralization in this area. The Nianzigou Mo deposit is located close to the northern margin of the North China Craton and in the eastern Central Asian Orogenic Belt and is a typical quartz-vein-type Mo deposit in the Xilamulun Mo ore belt. The granite in this deposit has high SiO2, Al2O3, K2O, and Na2O contents, and low MgO, CaO, and Fe2O3t contents. The granite is characterized by enrichments in large-ion lithophile elements and depletions in high-field-strength elements and, in particular, Sr, Ti, and P. The granite has high contents of rare-earth elements, is enriched in light rare-earth elements, and has marked negative Eu anomalies. The granite is an alkaline and calc-alkaline and metaluminous A-type granite. The zircon U-Pb ages of the monzogranite and granite porphyry are 157.2 ± 0.3 and 154.4 ± 0.4 Ma. The model age obtained by Re-Os isotopic dating is 154.3 ± 1.7 Ma, indicating that molybdenite mineralization also occurred during the Late Jurassic period. Given that the molybdenite Re contents are 7.8–24.9 ppm (average = 16.8 ppm), the ore-forming materials of the Nianzigou Mo deposit had a mixed crust–mantle source, but were mainly derived from the lower crust. Based on the geology and geochemistry, we propose that the Nianzigou Mo deposit formed in a postorogenic extensional tectonic setting associated with the southward subduction of the Mongol–Okhotsk oceanic plate.
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Ouyang, Yuan, Wunian Yang, Hanxiao Huang, Hong Liu, Jianlong Zhang, and Jianhua Zhang. "Metallogenic Dynamics Background of Ga’erqiong Cu-Au Deposit in Tibet, China." Earth Sciences Research Journal 21, no. 2 (April 1, 2017): 59–65. http://dx.doi.org/10.15446/esrj.v21n2.65192.
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The Ga’erqiong Cu-Au deposit, which sits on the north side of the Coqên-Xainzamagmatite belt, is a large-scale skarn-type deposit, whose ore body has formed in the skarn zone in the contact part of quartz diorite and marble of Duoai formation or the cracks of quartz diorite. Its mineralization is closely related to quartz diorite. And granite porphyry-related molybdenum ore still exists in its deep part. Currently, there are disputes about the metallogenic dynamics background of this deposit. From previous studies, this paper carried out zircon LA-LCPMS U-Pb dating and petrogeochemistry study for quartz diorite of Ga’erqiong Cu-Au deposit. The testing result indicates: quartz diorite and granite porphyry were formed respectively in 88±2Ma and 83±1Ma, belonging to the magmatic activity of the early stage of Upper Cretaceous; quartz diorite and granite porphyry have geochemical characteristics similar to those of island arc rock of subduction zone and geochemical indexes similar to “adakite.” Combining with the regional tectonic evolution, we think that quartz diorite and granite porphyry were all formed in the extension environment after the collision of Lhasa block and Qiangtang block. Quartz diorite is the result of the migmatization of basic melt and acid melt evoked by asthenosphere material raise caused by lower crustal delamination; the formation of granite porphyry may be crust-mantle material’s partial melting results due to delaminated lower crustal. Therefore, Ga’erqiongskarn-type Cu-Au deposit belongs to the metallogenic response to the collisional orogeny in the closing process of Meso-Tethys.
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Li, Chengsheng, Lingwei Kong, Rongjun Shu, Ran An, and Xianwei Zhang. "Disintegration characteristics in granite residual soil and their relationship with the collapsing gully in South China." Open Geosciences 12, no. 1 (October 19, 2020): 1116–26. http://dx.doi.org/10.1515/geo-2020-0178.
Full textAbstract:
AbstractThe climate is a significant factor affecting the collapsing gully in weathered granite areas, and most of the surface layers of the collapsed area comprise granite residual soil. Granite residual soil has complex disintegration characteristics under different initial water content conditions. Besides, its disintegration characteristic is an essential factor for collapsing gully. Therefore, disintegration tests, triaxial shear tests, nuclear magnetic resonance tests, and hydraulic conductivity tests are conducted under torridity and rainstorm conditions in order to study the disintegration characteristics of granite residual soil. The results of disintegration test showed that the initial disintegration rate of granite residual soil increased rapidly with the decrease in water content, while the relationship between disintegration rate and water content in the later stage of disintegration is unclear. When soaked, the maximum decrease in cohesion was 44.48%, the hydraulic conductivity became six times larger, and the amplitude of the T2 curve increased by about 40%, which reduced the strength of the soil and provided better access for rainwater infiltration to deeper stratum. The results show that the microstructure of granite residual soil would be damaged and the disintegration would occur after a rainstorm at low water content. Micropores would be formed inside the sample after soaking, resulting in destroying the continuity of the material.