Pub Date : 2025-03-08DOI: 10.1016/j.oregeorev.2025.106535
Rong Xu , Rolf L. Romer , Jun Deng
Major Sn-Cu deposits in the Gejiu ore district are genetically related to granitic intrusions. As Sn and Cu are lost during magma evolution in oxidized and reduced systems, respectively, they do not enrich together in the same magma. Therefore, the formation of Sn-Cu deposits in magmatic systems is debated. In particular, it is unclear whether Cu was added during late-stage magma evolution or after the crystallization of the magma. We address this question by analyzing tourmaline from the Tangziwa Sn-Cu deposit. The uniform B isotopic compositions of tourmaline (δ11B = −16.61 to −14.45 ‰) indicate that it crystallized from granitic melts or magmatic hydrothermal fluids. The chemical compositions of tourmaline track the evolution of fluids and melts from which tourmaline crystallized and record the availability of compatible elements. Tourmaline has high Sn contents, which shows that Sn was abundant in the melt. In contrast, the Cu contents in toumaline (less than 15 ppm) are low as for typical Sn-rich granites and much lower than in tourmaline from Cu-rich magmas that form Cu-Mo-Au porphyry deposits (Cu contents in such tourmaline may reach ∼1000 ppm). This implies that the granitic melts from Tangziwa had low Cu contents and these melts could not be the source of Cu in the deposit. Our data demonstrate that Cu was introduced after crystallization of tourmaline, possibly by the same fluid that resulted in extensive alteration of the granitic rocks and the mobilization of Sn from magmatic minerals to form alteration, skarn, vein, and sulfide type Sn deposits.
{"title":"Tourmaline compositions trace the sources of metals in the Tangziwa Sn-Cu deposit, Gejiu ore district, China","authors":"Rong Xu , Rolf L. Romer , Jun Deng","doi":"10.1016/j.oregeorev.2025.106535","DOIUrl":"10.1016/j.oregeorev.2025.106535","url":null,"abstract":"<div><div>Major Sn-Cu deposits in the Gejiu ore district are genetically related to granitic intrusions. As Sn and Cu are lost during magma evolution in oxidized and reduced systems, respectively, they do not enrich together in the same magma. Therefore, the formation of Sn-Cu deposits in magmatic systems is debated. In particular, it is unclear whether Cu was added during late-stage magma evolution or after the crystallization of the magma. We address this question by analyzing tourmaline from the Tangziwa Sn-Cu deposit. The uniform B isotopic compositions of tourmaline (δ<sup>11</sup>B = −16.61 to −14.45 ‰) indicate that it crystallized from granitic melts or magmatic hydrothermal fluids. The chemical compositions of tourmaline track the evolution of fluids and melts from which tourmaline crystallized and record the availability of compatible elements. Tourmaline has high Sn contents, which shows that Sn was abundant in the melt. In contrast, the Cu contents in toumaline (less than 15 ppm) are low as for typical Sn-rich granites and much lower than in tourmaline from Cu-rich magmas that form Cu-Mo-Au porphyry deposits (Cu contents in such tourmaline may reach ∼1000 ppm). This implies that the granitic melts from Tangziwa had low Cu contents and these melts could not be the source of Cu in the deposit. Our data demonstrate that Cu was introduced after crystallization of tourmaline, possibly by the same fluid that resulted in extensive alteration of the granitic rocks and the mobilization of Sn from magmatic minerals to form alteration, skarn, vein, and sulfide type Sn deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"180 ","pages":"Article 106535"},"PeriodicalIF":3.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.oregeorev.2025.106545
Yiting Zhu , Xiaofeng Li , Chunzeng Wang , Xinglin Wei , David R. Lentz
Rare metal deposits are generally associated with highly fractionated granites with unique geochemical signatures and the mineralization is controlled by composition of magmas, degree of magma fractionation, and magmatic-hydrothermal processes. The Ganfang rare metal deposit, located in Jiangxi Province, south China, is hosted within a strongly peraluminous, P and F-rich S-type rare-metal granite pluton (the Ganfang composite granite pluton) of Early Cretaceous age in the Jiuling Neoproterozoic granitic batholith. The pluton comprises two-mica monzogranite, topaz-bearing muscovite-albite granite, and felsite (locally aplitic) dikes. The topaz-bearing muscovite-albite granite is highly enriched in Li, Ta, Sn, Nb, Be, Rb, and Cs, while the felsite displays ultra-high enrichment of P, Li, Cs, Rb, Be, W, Sn, Nb, and Ta. The cassiterite U–Pb (137–140 Ma), monazite U–Pb (∼140 Ma), and muscovite Ar–Ar (140–142 Ma) ages indicate a coeval magmatic association for the pluton. Nd isotopic compositions indicate magmatic origination in the Late Paleoproterozoic metasedimentary basement. However, the significant differences in contents of SiO2, Al2O3, Li2O, P2O5, Rb2O, Cs2O, and F among these three components suggest unlikely a single parental magma source. The columbite minerals in the topaz-bearing muscovite-albite granite show complex replacement textures and unique chemical composition, suggesting involvement of locally Ta-saturated magma and melt-fluid metasomatism during the magma evolution process. The felsite shows high F (up to 1 wt%), P2O5 (up to 1.2 wt%), and Li2O (up to 1.5 wt%), indicating that the magma sequestered a large quantity of incompatible elements and ascended rapidly through the melt column to its emplacement level. In summary, enrichment of source magmas with rare metals, extreme fractionation, and melt-fluid metasomatism are the key factors in controlling genesis of the Ganfang Li-Rb-Cs-Be-Ta-Sn deposit.
{"title":"Genesis of the Ganfang Li-Rb-Cs-Be-Ta-Sn rare metal deposit: Evidence from geochemistry, geochronology, and Nd isotopes","authors":"Yiting Zhu , Xiaofeng Li , Chunzeng Wang , Xinglin Wei , David R. Lentz","doi":"10.1016/j.oregeorev.2025.106545","DOIUrl":"10.1016/j.oregeorev.2025.106545","url":null,"abstract":"<div><div>Rare metal deposits are generally associated with highly fractionated granites with unique geochemical signatures and the mineralization is controlled by composition of magmas, degree of magma fractionation, and magmatic-hydrothermal processes. The Ganfang rare metal deposit, located in Jiangxi Province, south China, is hosted within a strongly peraluminous, P and F-rich S-type rare-metal granite pluton (the Ganfang composite granite pluton) of Early Cretaceous age in the Jiuling Neoproterozoic granitic batholith. The pluton comprises two-mica monzogranite, topaz-bearing muscovite-albite granite, and felsite (locally aplitic) dikes. The topaz-bearing muscovite-albite granite is highly enriched in Li, Ta, Sn, Nb, Be, Rb, and Cs, while the felsite displays ultra-high enrichment of P, Li, Cs, Rb, Be, W, Sn, Nb, and Ta. The cassiterite U–Pb (137–140 Ma), monazite U–Pb (∼140 Ma), and muscovite Ar–Ar (140–142 Ma) ages indicate a coeval magmatic association for the pluton. Nd isotopic compositions indicate magmatic origination in the Late Paleoproterozoic metasedimentary basement. However, the significant differences in contents of SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, Li<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub>, Rb<sub>2</sub>O, Cs<sub>2</sub>O, and F among these three components suggest unlikely a single parental magma source. The columbite minerals in the topaz-bearing muscovite-albite granite show complex replacement textures and unique chemical composition, suggesting involvement of locally Ta-saturated magma and melt-fluid metasomatism during the magma evolution process. The felsite shows high F (up to 1 wt%), P<sub>2</sub>O<sub>5</sub> (up to 1.2 wt%), and Li<sub>2</sub>O (up to 1.5 wt%), indicating that the magma sequestered a large quantity of incompatible elements and ascended rapidly through the melt column to its emplacement level. In summary, enrichment of source magmas with rare metals, extreme fractionation, and melt-fluid metasomatism are the key factors in controlling genesis of the Ganfang Li-Rb-Cs-Be-Ta-Sn deposit.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106545"},"PeriodicalIF":3.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-06DOI: 10.1016/j.oregeorev.2025.106546
Qingling Xiao , Taofa Zhou , Noel C. White , Shiwei Wang , Jin Liu , Xuanxuan Li
Epidote is one of the main alteration minerals in propylitic alteration, and its mineral chemistry has been shown to provide vectors to assist in exploration for hidden arc-related porphyry copper deposits hosted in volcanic rocks. However, it is unknown whether the same vectors are applicable in exploration for porphyry deposits hosted in carbonates. Chating copper–gold deposit in the Middle Lower Yangtze River Metallogenic Belt of eastern China is a porphyry deposit associated with limestone wall rocks. We systematically analyzed epidote associated with Chating deposit, using EMPA and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to assess the factors controlling epidote geochemistry and the effectiveness of epidote chemistry as a vector in porphyry deposit which hosts in carbonates.
The petrographic study showed that there are three types of epidote in Chating: Ep1 (vein type), Ep2 (replacing magmatic minerals such as plagioclase and amphibole), and Ep3 (replacing skarn minerals such as garnet). All are hosted in the ore bearing quartz diorite porphyry. The major and trace element analysis results show that epidotes in Chating are enriched in Ca, Mn, Zn, Mg, P, Ti, Sr, As and Sb, with higher Ca and Al in Ep3 than in Ep1 and Ep2, and all epidotes are depleted in Cu, Au, Mo and Ag. Epidote chemistry in Chating varies with distance to the ore deposit center, with As, Sb, Pb, Ca and Al high distal from the deposit, whereas Fe, Sn and Fe/Al ratios are low. However, Mn, Zn, Cu and Au, which have proven to be effective vectors in subduction porphyry deposits, did not show systematic spatial variations. We suggest that epidote chemistry in Chating is controlled by several factors, including fluid composition, temperature, oxygen fugacity and the degree of fluid-rock interaction. The dominant factors that resulted in the restricted scale of propylitic alteration, and differences in the spatial trend of elements in epidote between Chating and subduction related porphyry deposits is the wall rock lithology and the degree of fluid-wall rock interaction. The spatial trends of As, Sb, Pb, Ca, Al, Fe, and Sn, and the content of Cu, Au and Mo in Chating epidote can also provide vectoring and fertility information, with potential to be applied in exploration for carbonate hosted porphyry deposits elsewhere.
{"title":"Epidote geochemistry of the Chating porphyry Cu-Au deposit, eastern China: Metallogenic and exploration implications for porphyry Cu deposits associated with carbonate wall rocks","authors":"Qingling Xiao , Taofa Zhou , Noel C. White , Shiwei Wang , Jin Liu , Xuanxuan Li","doi":"10.1016/j.oregeorev.2025.106546","DOIUrl":"10.1016/j.oregeorev.2025.106546","url":null,"abstract":"<div><div>Epidote is one of the main alteration minerals in propylitic alteration, and its mineral chemistry has been shown to provide vectors to assist in exploration for hidden arc-related porphyry copper deposits hosted in volcanic rocks. However, it is unknown whether the same vectors are applicable in exploration for porphyry deposits hosted in carbonates. Chating copper–gold deposit in the Middle Lower Yangtze River Metallogenic Belt of eastern China is a porphyry deposit associated with limestone wall rocks. We systematically analyzed epidote associated with Chating deposit, using EMPA and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to assess the factors controlling epidote geochemistry and the effectiveness of epidote chemistry as a vector in porphyry deposit which hosts in carbonates.</div><div>The petrographic study showed that there are three types of epidote in Chating: Ep1 (vein type), Ep2 (replacing magmatic minerals such as plagioclase and amphibole), and Ep3 (replacing skarn minerals such as garnet). All are hosted in the ore bearing quartz diorite porphyry. The major and trace element analysis results show that epidotes in Chating are enriched in Ca, Mn, Zn, Mg, P, Ti, Sr, As and Sb, with higher Ca and Al in Ep3 than in Ep1 and Ep2, and all epidotes are depleted in Cu, Au, Mo and Ag. Epidote chemistry in Chating varies with distance to the ore deposit center, with As, Sb, Pb, Ca and Al high distal from the deposit, whereas Fe, Sn and Fe/Al ratios are low. However, Mn, Zn, Cu and Au, which have proven to be effective vectors in subduction porphyry deposits, did not show systematic spatial variations. We suggest that epidote chemistry in Chating is controlled by several factors, including fluid composition, temperature, oxygen fugacity and the degree of fluid-rock interaction. The dominant factors that resulted in the restricted scale of propylitic alteration, and differences in the spatial trend of elements in epidote between Chating and subduction related porphyry deposits is the wall rock lithology and the degree of fluid-wall rock interaction. The spatial trends of As, Sb, Pb, Ca, Al, Fe, and Sn, and the content of Cu, Au and Mo in Chating epidote can also provide vectoring and fertility information, with potential to be applied in exploration for carbonate hosted porphyry deposits elsewhere.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106546"},"PeriodicalIF":3.2,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.oregeorev.2025.106542
Emma Losantos , Iñigo Borrajo , Iván Losada , Lluís Boixet , José M. Castelo Branco , Fernando Tornos
This paper provides a comprehensive review and a refined classification of Sn-W mineralisation in the Iberian Peninsula, based on an extensive review of the available literature. The study synthesises and clarifies previously published information to improve the understanding of the mineralisation processes and their tectonic and magmatic controls. The Sn and W mineralisation in the Iberian Peninsula exhibit a strong correlation with specific granitic suites primarily formed during the late to post-Variscan orogeny. Structural controls, particularly syn- to late-D3 strike-slip and/or extensional structures developed during the tectonic regime of the late Variscan, appear to be pivotal to facilitate the emplacement of this water-rich granitic magmas, that otherwise would have stalled at deeper environments, and the development of extensive hydrothermal systems. Two main mineralisation styles are identified: Sn-(Nb-Ta-Li) mineralisation under lithostatic pressure conditions, characterised by disseminated cassiterite in some pegmatites and altered granitic cupolas; and Sn-(Nb-Ta-Li) and W-(Sn) deposits formed at shallower levels within the brittle regime. The Sn-(Nb-Ta-Li) mineralisation is primarily associated with S-type granitic intrusions, while the W-(Sn) mineralisation also tends to be linked to these granitic suites, although several W-rich but Sn-poor deposits appear related to I-type granitoids. The metal enrichment in these magmas is likely due to a combination of inheritance from the source of the protoliths and magmatic evolution processes. The observed decoupling between Sn-rich and W-poor deposits versus W-(Sn)-rich deposits suggests contrasting behaviours of W and Sn during magmatic transport, the magmatic-hydrothermal transition, and the subsequent hydrothermal transport and deposition. Both types of deposits likely represent different settings and/or stages within a single magmatic-hydrothermal system.
{"title":"Sn and W mineralisation in the Iberian Peninsula","authors":"Emma Losantos , Iñigo Borrajo , Iván Losada , Lluís Boixet , José M. Castelo Branco , Fernando Tornos","doi":"10.1016/j.oregeorev.2025.106542","DOIUrl":"10.1016/j.oregeorev.2025.106542","url":null,"abstract":"<div><div>This paper provides a comprehensive review and a refined classification of Sn-W mineralisation in the Iberian Peninsula, based on an extensive review of the available literature. The study synthesises and clarifies previously published information to improve the understanding of the mineralisation processes and their tectonic and magmatic controls. The Sn and W mineralisation in the Iberian Peninsula exhibit a strong correlation with specific granitic suites primarily formed during the late to post-Variscan orogeny. Structural controls, particularly syn- to late-D<sub>3</sub> strike-slip and/or extensional structures developed during the tectonic regime of the late Variscan, appear to be pivotal to facilitate the emplacement of this water-rich granitic magmas, that otherwise would have stalled at deeper environments, and the development of extensive hydrothermal systems. Two main mineralisation styles are identified: Sn-(Nb-Ta-Li) mineralisation under lithostatic pressure conditions, characterised by disseminated cassiterite in some pegmatites and altered granitic cupolas; and Sn-(Nb-Ta-Li) and W-(Sn) deposits formed at shallower levels within the brittle regime. The Sn-(Nb-Ta-Li) mineralisation is primarily associated with S-type granitic intrusions, while the W-(Sn) mineralisation also tends to be linked to these granitic suites, although several W-rich but Sn-poor deposits appear related to I-type granitoids. The metal enrichment in these magmas is likely due to a combination of inheritance from the source of the protoliths and magmatic evolution processes. The observed decoupling between Sn-rich and W-poor deposits versus W-(Sn)-rich deposits suggests contrasting behaviours of W and Sn during magmatic transport, the magmatic-hydrothermal transition, and the subsequent hydrothermal transport and deposition. Both types of deposits likely represent different settings and/or stages within a single magmatic-hydrothermal system.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106542"},"PeriodicalIF":3.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.oregeorev.2025.106534
Ya-qi Huang , Ming-qian Wu , Jian-wen Yang , Xue-ming Teng , Cong Ao , Germain Kaningu Bishikwabo , Kun-feng Qiu
The sandstone-type uranium deposits are the dominant source of uranium in China. The Qaidam Basin, the largest inland sedimentary basin from the Chinese northern Tibetan Plateau, is shaped by various tectonic processes from the surrounding East Kunlun, Altyn, and Qilian orogenic belts, and is characterized by uranium mineralization and enrichment of petroleum. The Shizigou Formation is identified as one of the U-bearing strata in the Qigequan area. We present a case study at the Qigequan area in the southwestern edge of the Qaidam Basin, to investigate the governing factors for anomalous uranium enrichment in this stratum. U-Pb dating of detrital zircon from sandstones of the Shizigou Formation reveales two age peaks at 450 Ma and 260 Ma, respectively. The zircon CL images suggest that the majority of zircon grains assessed are magmatic origin, though some show complex core-rim texture, irregular shape core with overgrowth domains, patched zoning and sector zoning, indicating a metamorphic origin. The bimodal age distribution, textures, and REE distribution of the selected detrital zircon grains all indicate that the sedimentary source of the Shizigou Formation originated from the Qimantagh area (East Kunlun). The paleoclimate proxies, namely the Sr/Cu, Sr/Ba, V/Sc, V/Cr, and Fe3+/Fe2+ values, combined with the chemical index of alteration (CIA) and index of compositional variation (ICV) reveal that the Shizigou Formation was formed in a relatively arid and oxidized environment that suffered a low degree of chemical weathering, which provides condition for the transportation of U-bearing ore-forming fluids. The escaping organic matters in the underlying strata act as reducing materials that control the precipitation of uranium-complexes in ore-forming fluids. On the other hand, the surrounding strata containing the source rocks and hydrocarbon make an effective barrier for the uranium orebodies to be preserved. The source of ore-forming materials, sedimentary environment and organic matters have made significant contributions to the uranium mineralization in the southwest Qaidam Basin.
{"title":"Sedimentary and ore-forming characteristics of uranium mineralization in the Shizigou formation from the Southwest Qaidam Basin, Northwest China","authors":"Ya-qi Huang , Ming-qian Wu , Jian-wen Yang , Xue-ming Teng , Cong Ao , Germain Kaningu Bishikwabo , Kun-feng Qiu","doi":"10.1016/j.oregeorev.2025.106534","DOIUrl":"10.1016/j.oregeorev.2025.106534","url":null,"abstract":"<div><div>The sandstone-type uranium deposits are the dominant source of uranium in China. The Qaidam Basin, the largest inland sedimentary basin from the Chinese northern Tibetan Plateau, is shaped by various tectonic processes from the surrounding East Kunlun, Altyn, and Qilian orogenic belts, and is characterized by uranium mineralization and enrichment of petroleum. The Shizigou Formation is identified as one of the U-bearing strata in the Qigequan area. We present a case study at the Qigequan area in the southwestern edge of the Qaidam Basin, to investigate the governing factors for anomalous uranium enrichment in this stratum. U-Pb dating of detrital zircon from sandstones of the Shizigou Formation reveales two age peaks at 450 Ma and 260 Ma, respectively. The zircon CL images suggest that the majority of zircon grains assessed are magmatic origin, though some show complex core-rim texture, irregular shape core with overgrowth domains, patched zoning and sector zoning, indicating a metamorphic origin. The bimodal age distribution, textures, and REE distribution of the selected detrital zircon grains all indicate that the sedimentary source of the Shizigou Formation originated from the Qimantagh area (East Kunlun). The paleoclimate proxies, namely the Sr/Cu, Sr/Ba, V/Sc, V/Cr, and Fe<sup>3+</sup>/Fe<sup>2+</sup> values, combined with the chemical index of alteration (CIA) and index of compositional variation (ICV) reveal that the Shizigou Formation was formed in a relatively arid and oxidized environment that suffered a low degree of chemical weathering, which provides condition for the transportation of U-bearing ore-forming fluids. The escaping organic matters in the underlying strata act as reducing materials that control the precipitation of uranium-complexes in ore-forming fluids. On the other hand, the surrounding strata containing the source rocks and hydrocarbon make an effective barrier for the uranium orebodies to be preserved. The source of ore-forming materials, sedimentary environment and organic matters have made significant contributions to the uranium mineralization in the southwest Qaidam Basin.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106534"},"PeriodicalIF":3.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.oregeorev.2025.106531
Chang Fan , Hao-Cheng Yu , Murat Taner Tamer , Lian Zhang , Jie Wang , Pei-Xiong Liu , Xian-Fa Xue , Chao Li , Yu-Xi Wang
The Nanban quartz vein-hosted gold deposit is located in the West Qinling Orogenic Belt, and the NS-trending faults control gold mineralization. This study integrates deposit geology, hydrothermal monazite U-Pb dating, trace element composition of sulfides, and sulfur isotope characteristics of the Nanban gold deposit, in comparison with the nearby Ludousou reduced intrusion-related gold deposit, to establish the genetic model of the deposit. Hydrothermal monazite U-Pb dating indicates that gold mineralization occurred at 229.8 ± 2.5 Ma. The study has identified two generations of pyrite (Py1 and Py2) and two generations of arsenopyrite (Apy1 and Apy2). The early Py1 and Apy1 samples exhibit compositional homogeneity, with minimal fractures and mineral inclusions. In contrast, Py2 and Apy2 exhibit a greater abundance of mineral inclusions and are extensively fractured, with quartz, galena, and sphalerite filling the fractures. Geochemical analyses show that Py1 and Apy1 have higher concentrations of Co and Ni, while Py2 and Apy2 are enriched in Au, As, Cu, Ag, and Pb. The Ag/Co ratio of Py1 is less than 0.1, while the Ag/Co ratio of Py2 is generally greater than 0.1. All these characteristics indicate that the Py1 and Apy1 might have formed under mild boiling conditions, and Py2 and Apy2 may have occurred under highly variable physicochemical conditions, such as violent fluid boiling. Fluid boiling likely destabilized gold-sulfur complexes, leading to gold precipitation. The sulfur isotope data of the pyrite range from +2.17 ‰ to +6.54 ‰, indicating a deviation from the values observed in nearby magmatic-hydrothermal deposits but demonstrating a similarity to those of authigenic pyrite within the underlying Cambrian black shale. The ore-forming fluids are inferred to originate from metamorphic devolatilization of underlying strata during the Late Triassic syn-collisional event. Differences in mineralization age, ore-forming material sources, and geochemical characteristics between the Nanban and nearby Ludousou gold deposits further support a non-magmatic-hydrothermal origin. The results support the classification of the Nanban gold as orogenic gold deposit. This study further demonstrates that vein-type gold deposits hosted in granitoids do not necessarily have a genetic relationship with the granitoids. Through the integration of geochronological research with sulfur isotope analysis, a more precise determination can be achieved.
{"title":"Ore genesis of the Nanban gold deposit, West Qinling Orogen: Insights from monazite geochronology and geochemistry of sulfides","authors":"Chang Fan , Hao-Cheng Yu , Murat Taner Tamer , Lian Zhang , Jie Wang , Pei-Xiong Liu , Xian-Fa Xue , Chao Li , Yu-Xi Wang","doi":"10.1016/j.oregeorev.2025.106531","DOIUrl":"10.1016/j.oregeorev.2025.106531","url":null,"abstract":"<div><div>The Nanban quartz vein-hosted gold deposit is located in the West Qinling Orogenic Belt, and the NS-trending faults control gold mineralization. This study integrates deposit geology, hydrothermal monazite U-Pb dating, trace element composition of sulfides, and sulfur isotope characteristics of the Nanban gold deposit, in comparison with the nearby Ludousou reduced intrusion-related gold deposit, to establish the genetic model of the deposit. Hydrothermal monazite U-Pb dating indicates that gold mineralization occurred at 229.8 ± 2.5 Ma. The study has identified two generations of pyrite (Py1 and Py2) and two generations of arsenopyrite (Apy1 and Apy2). The early Py1 and Apy1 samples exhibit compositional homogeneity, with minimal fractures and mineral inclusions. In contrast, Py2 and Apy2 exhibit a greater abundance of mineral inclusions and are extensively fractured, with quartz, galena, and sphalerite filling the fractures. Geochemical analyses show that Py1 and Apy1 have higher concentrations of Co and Ni, while Py2 and Apy2 are enriched in Au, As, Cu, Ag, and Pb. The Ag/Co ratio of Py1 is less than 0.1, while the Ag/Co ratio of Py2 is generally greater than 0.1. All these characteristics indicate that the Py1 and Apy1 might have formed under mild boiling conditions, and Py2 and Apy2 may have occurred under highly variable physicochemical conditions, such as violent fluid boiling. Fluid boiling likely destabilized gold-sulfur complexes, leading to gold precipitation. The sulfur isotope data of the pyrite range from +2.17 ‰ to +6.54 ‰, indicating a deviation from the values observed in nearby magmatic-hydrothermal deposits but demonstrating a similarity to those of authigenic pyrite within the underlying Cambrian black shale. The ore-forming fluids are inferred to originate from metamorphic devolatilization of underlying strata during the Late Triassic <em>syn</em>-collisional event. Differences in mineralization age, ore-forming material sources, and geochemical characteristics between the Nanban and nearby Ludousou gold deposits further support a non-magmatic-hydrothermal origin. The results support the classification of the Nanban gold as orogenic gold deposit. This study further demonstrates that vein-type gold deposits hosted in granitoids do not necessarily have a genetic relationship with the granitoids. Through the integration of geochronological research with sulfur isotope analysis, a more precise determination can be achieved.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106531"},"PeriodicalIF":3.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.oregeorev.2025.106532
Nilay Gülyüz
This study employs multiple low-temperature thermochronology techniques—Apatite Fission Track (AFT), Apatite (U-Th)/He (AHe), and Zircon (U-Th)/He (ZHe)—to reveal the cooling, exhumation, and preservation history of the İspir-Ulutaş porphyry Cu-Mo deposit, the oldest known porphyry deposit in the Eastern Pontides (∼131 Ma), and to investigate the relative scarcity of the porphyry systems in the Eastern Pontides.
The inverse thermal history model reveals a complex multi-stage cooling/exhumation history of the İspir-Ulutaş deposit. The ZHe data and thermal model indicate that the deposit was emplaced at a paleodepth of over 5 km at ∼ 131 Ma. The deposit experienced two major exhumation stages. The first, occurring during the Middle Eocene (∼43–38 Ma), was triggered by anomalous regional compressional forces likely due to the subduction of a mid-ocean ridge along the Bitlis-Zagros suture zone. During this phase, the porphyry system was exhumed to near-surface levels, but only its uppermost parts were eroded. Shortly after, post-collisional volcanic and sedimentary sequences buried the deposit, temporarily protecting it from further erosion. The second major exhumation phase, recorded by AHe data, began around 18 Ma and continues to the present, resulting in approximately 2.5 km of erosion. This phase aligns with the timing of the Arabia-Eurasia collision, which caused gradual uplift and exhumation across the region.
In summary, the deep emplacement of the İspir-Ulutaş deposit (>5 km), combined with the post-mineralization burial by Eocene sequences, extended slow exhumation, and drier/continental climatic conditions, played key roles in the preservation of the porphyry system. Lastly, the study proposes that areas in the southern Eastern Pontides, particularly those covered by Eocene sequences, may offer promising exploration targets for new porphyry deposits.
{"title":"Thermal-tectonic history of the İspir-Ulutaş porphyry Cu-Mo deposit, Eastern Pontides: Implications for regional tectonics and exploration of porphyry systems","authors":"Nilay Gülyüz","doi":"10.1016/j.oregeorev.2025.106532","DOIUrl":"10.1016/j.oregeorev.2025.106532","url":null,"abstract":"<div><div>This study employs multiple low-temperature thermochronology techniques—Apatite Fission Track (AFT), Apatite (U-Th)/He (AHe), and Zircon (U-Th)/He (ZHe)—to reveal the cooling, exhumation, and preservation history of the İspir-Ulutaş porphyry Cu-Mo deposit, the oldest known porphyry deposit in the Eastern Pontides (∼131 Ma), and to investigate the relative scarcity of the porphyry systems in the Eastern Pontides.</div><div>The inverse thermal history model reveals a complex multi-stage cooling/exhumation history of the İspir-Ulutaş deposit. The ZHe data and thermal model indicate that the deposit was emplaced at a paleodepth of over 5 km at ∼ 131 Ma. The deposit experienced two major exhumation stages. The first, occurring during the Middle Eocene (∼43–38 Ma), was triggered by anomalous regional compressional forces likely due to the subduction of a mid-ocean ridge along the Bitlis-Zagros suture zone. During this phase, the porphyry system was exhumed to near-surface levels, but only its uppermost parts were eroded. Shortly after, post-collisional volcanic and sedimentary sequences buried the deposit, temporarily protecting it from further erosion. The second major exhumation phase, recorded by AHe data, began around 18 Ma and continues to the present, resulting in approximately 2.5 km of erosion. This phase aligns with the timing of the Arabia-Eurasia collision, which caused gradual uplift and exhumation across the region.</div><div>In summary, the deep emplacement of the İspir-Ulutaş deposit (>5 km), combined with the post-mineralization burial by Eocene sequences, extended slow exhumation, and drier/continental climatic conditions, played key roles in the preservation of the porphyry system. Lastly, the study proposes that areas in the southern Eastern Pontides, particularly those covered by Eocene sequences, may offer promising exploration targets for new porphyry deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106532"},"PeriodicalIF":3.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.oregeorev.2025.106512
Yi-Zi Zou , Shan-Shan Li , Huai-Feng Zhang , Murat Taner Tamer , Germain Kaningu Bishikwabo , Espine Tuyakula Shivute , Wen-Ming Dong , Absai Vatuva , Chuan-Heng Zhang
The Pan-African Orogeny induced extensive magmatic activity in the Central Zone of the Damara Orogenic Belt in Southwest Africa. However, the genesis of these granitoid complexes remains a subject of considerable uncertainty. The Salem granite, situated within the Central Zone of the Damara Orogenic Belt, serves as a prime subject for the investigation of the tectonic evolution of this belt. This paper utilizes a multidisciplinary approach encompassing petrography, whole rock geochemistry, U-Pb geochronology on zircon and monazite from quartz-monzonites and granodiorites collected from the Salem granitic complex. It discusses the petrogenesis, magmatic and metamorphic evolution, as well as its implication for the Damara Orogeny. The analysis of whole rock geochemical data suggests that the Salem granite are primarily peraluminous, ferroan, and alkali-calcic to alkalic in nature. These rocks exhibit elevated concentrations of high field strength elements (e.g., Th, U, Nb, Zr) and demonstrate light rare earth elements (LREE) enrichment relative to heavy rare earth elements (HREE). These geochemical characteristics bear a resemblance to those observed in A-type peraluminous granites. The magma may have undergone fractionation of plagioclase, biotite, and garnet during its evolution. Zircon and monazite U-Pb data reveal a magma crystallization age of 539–538 Ma, which overlaps with the extensive 540–490 Ma magmatic activity in the Damara Orogenic Belt. Their metamorphic age of 528–526 Ma is consistent with the 530–520 Ma regional peak granulite facies metamorphism. The metamorphic age of 501–484 Ma these granites coincides with the timing of the post-orogenic magmatism and uranium mineralization age of 500–480 Ma. Their Nb/Ta (19.0–71.2) and Zr/Hf ratios (83.5–146.0) are significantly higher than those of the depleted mantle (Nb/Ta = 17.5, Zr/Hf = 36.3) and crust (Nb/Ta = 12.4, Zr/Hf = 35.5), suggesting that the magma may source from an enriched mantle. The presence of large ion lithophile elements such as Pb, Rb and K indicates that the mantle-derived magmas interacted with the crustal material during their ascent. We propose that the magma source of Salem granite was primarily derived from the mantle and was subsequently contaminated by crustal materials during the continental collision of Congo Craton and Kalahari Craton.
{"title":"Petrogenesis, magmatic and metamorphic evolution of Salem granite: Implications for the Damara Orogeny","authors":"Yi-Zi Zou , Shan-Shan Li , Huai-Feng Zhang , Murat Taner Tamer , Germain Kaningu Bishikwabo , Espine Tuyakula Shivute , Wen-Ming Dong , Absai Vatuva , Chuan-Heng Zhang","doi":"10.1016/j.oregeorev.2025.106512","DOIUrl":"10.1016/j.oregeorev.2025.106512","url":null,"abstract":"<div><div>The Pan-African Orogeny induced extensive magmatic activity in the Central Zone of the Damara Orogenic Belt in Southwest Africa. However, the genesis of these granitoid complexes remains a subject of considerable uncertainty. The Salem granite, situated within the Central Zone of the Damara Orogenic Belt, serves as a prime subject for the investigation of the tectonic evolution of this belt. This paper utilizes a multidisciplinary approach encompassing petrography, whole rock geochemistry, U-Pb geochronology on zircon and monazite from quartz-monzonites and granodiorites collected from the Salem granitic complex. It discusses the petrogenesis, magmatic and metamorphic evolution, as well as its implication for the Damara Orogeny. The analysis of whole rock geochemical data suggests that the Salem granite are primarily peraluminous, ferroan, and alkali-calcic to alkalic in nature. These rocks exhibit elevated concentrations of high field strength elements (e.g., Th, U, Nb, Zr) and demonstrate light rare earth elements (LREE) enrichment relative to heavy rare earth elements (HREE). These geochemical characteristics bear a resemblance to those observed in A-type peraluminous granites. The magma may have undergone fractionation of plagioclase, biotite, and garnet during its evolution. Zircon and monazite U-Pb data reveal a magma crystallization age of 539–538 Ma, which overlaps with the extensive 540–490 Ma magmatic activity in the Damara Orogenic Belt. Their metamorphic age of 528–526 Ma is consistent with the 530–520 Ma regional peak granulite facies metamorphism. The metamorphic age of 501–484 Ma these granites coincides with the timing of the post-orogenic magmatism and uranium mineralization age of 500–480 Ma. Their Nb/Ta (19.0–71.2) and Zr/Hf ratios (83.5–146.0) are significantly higher than those of the depleted mantle (Nb/Ta = 17.5, Zr/Hf = 36.3) and crust (Nb/Ta = 12.4, Zr/Hf = 35.5), suggesting that the magma may source from an enriched mantle. The presence of large ion lithophile elements such as Pb, Rb and K indicates that the mantle-derived magmas interacted with the crustal material during their ascent. We propose that the magma source of Salem granite was primarily derived from the mantle and was subsequently contaminated by crustal materials during the continental collision of Congo Craton and Kalahari Craton.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106512"},"PeriodicalIF":3.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.oregeorev.2025.106540
Hangfei Ge , Yi Liang , Guogang Wang , Chunbo Zhou , Qiuming Pei , Xingyu Jiao , Haonan Huang
The Huangjindong gold deposit (∼80 t Au @ 5 g/t) is located in the middle segment of the Jiangnan Orogenic Belt, South China. Mineralization of the deposit is mainly controlled by the NE-trending faults and a series of EW-NWW-trending inverted folds, which are dominated by auriferous quartz veins, altered slates and breccias. As the gold-bearing minerals, pyrite and arsenopyrite are both classified into two generations (Py1, Py2, Apy-a and Apy-b). The mineralization comprises three stages, Py1 + quartz + sericite (stage I), Py2 + arsenopyrite + gold + galena + sphalerite + chalcopyrite + tetrahedrite + quartz (stage II), and quartz + chlorite + calcite (stage III). To understand the characteristics of gold mineralization and the ore-forming conditions, we conducted comprehensive studies of the fluid inclusions, EPMA, LA-ICP-MS and thermodynamic analyses. The microthermometric results reveal that the ore-forming fluids may have two temperature peaks at ∼180 °C and ∼280 °C. The EPMA results show that the fineness of the native gold ranges from 978 to 1000 (mean 995.9). The LA-ICP-MS analyses of fluid inclusions, pyrite and arsenopyrite formed at different stages reveal the distinct distributions of trace elements. Since the processed data from the LA-ICP-MS mapping analyses reveals that the Au/Ag values of Py2 (10–1000) and arsenopyrite (10–10,000) are higher than that of Py1 (0.1–100), we conducted thermodynamic calculations and plotted the 3D isopleth models for the gold solubility and the Au/Ag ratio. The results of this study suggest that gold mineralization mainly occurs in stage II with higher Au/Ag ratios and higher temperatures, and the decreased sulfur concentration might have caused large-scale gold precipitation.
{"title":"Gold mineralization of the Huangjindong gold deposit in the Jiangnan Orogen, South China: Constraints from fluid inclusions and LA-ICP-MS analysis of pyrite and arsenopyrite","authors":"Hangfei Ge , Yi Liang , Guogang Wang , Chunbo Zhou , Qiuming Pei , Xingyu Jiao , Haonan Huang","doi":"10.1016/j.oregeorev.2025.106540","DOIUrl":"10.1016/j.oregeorev.2025.106540","url":null,"abstract":"<div><div>The Huangjindong gold deposit (∼80 t Au @ 5 g/t) is located in the middle segment of the Jiangnan Orogenic Belt, South China. Mineralization of the deposit is mainly controlled by the NE-trending faults and a series of EW-NWW-trending inverted folds, which are dominated by auriferous quartz veins, altered slates and breccias. As the gold-bearing minerals, pyrite and arsenopyrite are both classified into two generations (Py1, Py2, Apy-a and Apy-b). The mineralization comprises three stages, Py1 + quartz + sericite (stage I), Py2 + arsenopyrite + gold + galena + sphalerite + chalcopyrite + tetrahedrite + quartz (stage II), and quartz + chlorite + calcite (stage III). To understand the characteristics of gold mineralization and the ore-forming conditions, we conducted comprehensive studies of the fluid inclusions, EPMA, LA-ICP-MS and thermodynamic analyses. The microthermometric results reveal that the ore-forming fluids may have two temperature peaks at ∼180 °C and ∼280 °C. The EPMA results show that the fineness of the native gold ranges from 978 to 1000 (mean 995.9). The LA-ICP-MS analyses of fluid inclusions, pyrite and arsenopyrite formed at different stages reveal the distinct distributions of trace elements. Since the processed data from the LA-ICP-MS mapping analyses reveals that the Au/Ag values of Py2 (10–1000) and arsenopyrite (10–10,000) are higher than that of Py1 (0.1–100), we conducted thermodynamic calculations and plotted the 3D isopleth models for the gold solubility and the Au/Ag ratio. The results of this study suggest that gold mineralization mainly occurs in stage II with higher Au/Ag ratios and higher temperatures, and the decreased sulfur concentration might have caused large-scale gold precipitation.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106540"},"PeriodicalIF":3.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1016/j.oregeorev.2025.106538
Xiaoyu Ge , Fan Yang , Zhenyu Qin , Leon Bagas , Hongying Li , Weidong Ren , Feifan Xu
Molybdenum (Mo) is an energy metal that plays a crucial role in numerous sectors of the national economy. China has been the world’s largest supplier of Mo, with most hosted by porphyry deposits. The Jinduicheng deposit is an important porphyry Mo deposit in the East Qinling Orogen of central China, with a proven reserve of 1.03 Mt Mo. Although early studies related to the genesis of the deposit, the details of the hydrothermal ore-forming processes remain unclear. Muscovite, a typical rock-forming mineral, has been widely used to trace ore-forming physio-chemical conditions and hydrothermal evolution. With this in mind, we carried out in-situ major and trace element analysis of muscovite from the mineralised granite porphyry and andesite porphyry in the Jinduicheng Mo deposit to reveal the changes in ore-forming physico-chemical conditions and hydrothermal mineralising processes. The studied muscovite samples are hydrothermal (or secondary) type with crystallisation temperatures of ∼ 152–364 °C for the altered granite porphyry and of ∼ 182–246 °C for the altered andesite porphyry, in response to the ore-forming temperature (150–360 °C) of the Jinduicheng deposit. The IV(F), IV(Cl), and IV(F/Cl) values of hydrothermal muscovite at the deposit range from 1.73 to 2.24, −4.02 to −2.12, and 3.67 to 5.88 for the altered granite porphyry, and from 1.58 to 1.78, −3.49 to −2.41, and 4.13 to 5.03 for the altered andesite porphyry, which indicates high F fugacity. During ore-forming processes, high oxygen and halogen fugacities promoted the formation and transportation of stable Cl- and hexavalent Mo complexes, which result in the enrichment of Mo. The Mo precipitation processes at Jinduicheng involve the progressive enrichment of Mo as magmatic and hydrothermal fluid differentiated. Higher oxygen and halogen fugacity favors the hexavalent state of Mo (H2MoO4, HMoO4-, or MoO42-), which facilitated the formation of stable complexes with hexavalent Mo. Medium to high-temperature fluids, enriched in CO2, also contributed to Mo transport through complex anions such as CO32– and HCO3-. Subsequently, fluid-rock interactions resulted in the formation of K-feldspar-quartz-sulfide and quartz-sulfide veins, with tectonic changes affecting fluid equilibrium and promoting Mo-sulfide precipitation. The late stage of Mo mineralisation, the mixing of hydrothermal fluids with meteoric water were added to the deposit, which significantly altered the mineralising system’s physicochemical conditions, destabilized the fluids, and facilitated Mo precipitation. This study also indicates that hydrothermal muscovite geochemistry is useful in clarifying the ore-forming process within hydrothermal systems.
{"title":"Hydrothermal muscovite geochemistry unravelling the ore-forming process of the Jinduicheng porphyry Mo deposit, East Qinling, China","authors":"Xiaoyu Ge , Fan Yang , Zhenyu Qin , Leon Bagas , Hongying Li , Weidong Ren , Feifan Xu","doi":"10.1016/j.oregeorev.2025.106538","DOIUrl":"10.1016/j.oregeorev.2025.106538","url":null,"abstract":"<div><div>Molybdenum (Mo) is an energy metal that plays a crucial role in numerous sectors of the national economy. China has been the world’s largest supplier of Mo, with most hosted by porphyry deposits. The Jinduicheng deposit is an important porphyry Mo deposit in the East Qinling Orogen of central China, with a proven reserve of 1.03 Mt Mo. Although early studies related to the genesis of the deposit, the details of the hydrothermal ore-forming processes remain unclear. Muscovite, a typical rock-forming mineral, has been widely used to trace ore-forming physio-chemical conditions and hydrothermal evolution. With this in mind, we carried out <em>in-situ</em> major and trace element analysis of muscovite from the mineralised granite porphyry and andesite porphyry in the Jinduicheng Mo deposit to reveal the changes in ore-forming physico-chemical conditions and hydrothermal mineralising processes. The studied muscovite samples are hydrothermal (or secondary) type with crystallisation temperatures of ∼ 152–364 °C for the altered granite porphyry and of ∼ 182–246 °C for the altered andesite porphyry, in response to the ore-forming temperature (150–360 °C) of the Jinduicheng deposit. The IV(F), IV(Cl), and IV(F/Cl) values of hydrothermal muscovite at the deposit range from 1.73 to 2.24, −4.02 to −2.12, and 3.67 to 5.88 for the altered granite porphyry, and from 1.58 to 1.78, −3.49 to −2.41, and 4.13 to 5.03 for the altered andesite porphyry, which indicates high F fugacity. During ore-forming processes, high oxygen and halogen fugacities promoted the formation and transportation of stable Cl<sup>-</sup> and hexavalent Mo complexes, which result in the enrichment of Mo. The Mo precipitation processes at Jinduicheng involve the progressive enrichment of Mo as magmatic and hydrothermal fluid differentiated. Higher oxygen and halogen fugacity favors the hexavalent state of Mo (H<sub>2</sub>MoO<sub>4</sub>, HMoO<sub>4</sub><sup>-</sup>, or MoO<sub>4</sub><sup>2-</sup>), which facilitated the formation of stable complexes with hexavalent Mo. Medium to high-temperature fluids, enriched in CO<sub>2</sub>, also contributed to Mo transport through complex anions such as CO<sub>3</sub><sup>2–</sup> and HCO<sub>3</sub><sup>-</sup>. Subsequently, fluid-rock interactions resulted in the formation of K-feldspar-quartz-sulfide and quartz-sulfide veins, with tectonic changes affecting fluid equilibrium and promoting Mo-sulfide precipitation. The late stage of Mo mineralisation, the mixing of hydrothermal fluids with meteoric water were added to the deposit, which significantly altered the mineralising system’s physicochemical conditions, destabilized the fluids, and facilitated Mo precipitation. This study also indicates that hydrothermal muscovite geochemistry is useful in clarifying the ore-forming process within hydrothermal systems.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"179 ","pages":"Article 106538"},"PeriodicalIF":3.2,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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