Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107023
Bei-Er Guo , Kui-Dong Zhao , Guo-Qi Liu , Qian Li , Wei Chen , Shao-Yong Jiang , Gregory M. Yaxley
The Yashan granitic complex, a multiphase, highly evolved granitic system, hosts one of the largest Ta-Nb-Li deposits in South China. Spatially, it comprises a composite pluton intruded by multiple albitite dikes (AD). The pluton exhibits a vertically zoned sequence of granitic rocks, progressing from two-mica granite (TMG) at the base through Li-mica granite (LG) and topaz lepidolite granite (TLG) to lepidolite quartz rock (LQR) at the top. Apatite is widespread in the Yashan complex and displays distinct morphologic and chemical variations. Three genetically distinct types have been identified: magmatic (Ap1), magmatic-hydrothermal overprinted (Ap2), and later hydrothermal (Ap3) apatite. Ap1 yields concordant U-Pb ages of 152.5 ± 0.6 Ma and exhibits geochemical characteristics similar to those of typical S-type granites. Fractional crystallization of plagioclase, monazite, and garnet controls the distribution of Sr, REE, and trace-elements. Ap2 displays porous textures, elevated Sr contents (up to 15,705 ppm), and high 87Sr/86Sr isotopic ratios, along with scattered U-Pb ages. The spatial association of Ap2 with hydrothermal Li-rich mica, as well as its enrichment in Nb and Ta, suggests fluid-mediated remobilization of rare metals. These features reflect metasomatic overprinting by hydrothermal fluids exsolved from the evolved magma. Ap3 records a discrete hydrothermal event with a late Cretaceous age of 87.2 ± 2.9 Ma. Collectively, these findings indicate that although hydrothermal alteration significantly modified mineral chemistry, magmatic differentiation remained the dominant control on rare-metal enrichment. Furthermore, the study highlights that Sr-rich apatite with low Th/U ratios (<1) in highly evolved granites can serve as a valuable indicator for constraining the timing of hydrothermal alteration.
{"title":"Magmatic evolution and late hydrothermal activity in the Yashan rare-metal granites, South China: Insights from apatite geochronology and geochemistry","authors":"Bei-Er Guo , Kui-Dong Zhao , Guo-Qi Liu , Qian Li , Wei Chen , Shao-Yong Jiang , Gregory M. Yaxley","doi":"10.1016/j.oregeorev.2025.107023","DOIUrl":"10.1016/j.oregeorev.2025.107023","url":null,"abstract":"<div><div>The Yashan granitic complex, a multiphase, highly evolved granitic system, hosts one of the largest Ta-Nb-Li deposits in South China. Spatially, it comprises a composite pluton intruded by multiple albitite dikes (AD). The pluton exhibits a vertically zoned sequence of granitic rocks, progressing from two-mica granite (TMG) at the base through Li-mica granite (LG) and topaz lepidolite granite (TLG) to lepidolite quartz rock (LQR) at the top. Apatite is widespread in the Yashan complex and displays distinct morphologic and chemical variations. Three genetically distinct types have been identified: magmatic (Ap1), magmatic-hydrothermal overprinted (Ap2), and later hydrothermal (Ap3) apatite. Ap1 yields concordant U-Pb ages of 152.5 ± 0.6 Ma and exhibits geochemical characteristics similar to those of typical S-type granites. Fractional crystallization of plagioclase, monazite, and garnet controls the distribution of Sr, REE, and trace-elements. Ap2 displays porous textures, elevated Sr contents (up to 15,705 ppm), and high <sup>87</sup>Sr/<sup>86</sup>Sr isotopic ratios, along with scattered U-Pb ages. The spatial association of Ap2 with hydrothermal Li-rich mica, as well as its enrichment in Nb and Ta, suggests fluid-mediated remobilization of rare metals. These features reflect metasomatic overprinting by hydrothermal fluids exsolved from the evolved magma. Ap3 records a discrete hydrothermal event with a late Cretaceous age of 87.2 ± 2.9 Ma. Collectively, these findings indicate that although hydrothermal alteration significantly modified mineral chemistry, magmatic differentiation remained the dominant control on rare-metal enrichment. Furthermore, the study highlights that Sr-rich apatite with low Th/U ratios (<1) in highly evolved granites can serve as a valuable indicator for constraining the timing of hydrothermal alteration.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107023"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107016
Yuting Yang , Xiaoxue Lu , Evgeniy V. Kislov , Feng Bai , Yan Liu
<div><div>Nephrite consists predominantly of fine-grained tremolite–actinolite aggregates and typically occurs at the contact between granite/granodiorite and dolomitic marble. Most previous studies have focused on the mineralogy, geochemistry, age, and ore-forming fluids of nephrite deposits. However, the detailed formation processes of nephrite remain unclear, particularly in terms of the occurrence of fine-grained tremolite aggregates in nephrite and whether granitoids can be directly replaced by nephrite. The Kavokta nephrite deposit is the largest dolomite-related nephrite deposit in Russia and is an ideal target for investigating the formation of nephrite deposits because it contains a relic mineral assemblage derived from granitoids and multiple generations of minerals that crystallized during nephrite formation. In this study, we undertook a comprehensive set of observations and analyses, including back-scattered electron (BSE) imaging, TESCAN integrated mineral analysis (TIMA), X-ray fluorescence spectrometry (XRF), inductively coupled plasma–mass spectrometry (ICP–MS), electron probe microanalysis (EPMA), laser ablation inductively coupled plasma–mass spectrometry (LA–ICP–MS), and isotope ratio mass spectrometry (IRMS), to constrain the genesis of the Kavokta nephrite deposit. The igneous minerals (e.g., apatite, allanite, titanite, thorite, rutile and ilmenite) in the nephrite are relics after metasomatism of the granitoids by ore-forming fluids. The relic igneous minerals, along with the metasomatic grossular and diopside, and other multi-stage mineral assemblages (e.g., epidote, tremolite, and talc; serpentine–talc; phlogopite–chlorite; tremolite–chlorite; and tremolite–talc) in the nephrite, record magmatic, contact metamorphic, and prograde and retrograde metasomatic stages. This suggests that the nephrite with fine-grained tremolite formed by the successive replacement of coarse-grained tremolite aggregates. Both green and white nephrite samples have similar rare earth and trace element features, characterized by moderate negative Eu anomalies, U enrichment, and Nb depletion. Hydrothermal zircons occur in two samples of green nephrite collected near the host granitoids. The samples have whole-rock Zr contents of 43 and 31 ppm, and the zircons yield a concordant <sup>206</sup>Pb/<sup>238</sup>U age of 343.9 ± 1.2 Ma (n = 10; MSWD = 2.3), similar to the age of the host granitoids. Oxygen and hydrogen isotope data indicate the ore-forming fluids in this deposit were predominantly meteoric water, very possibly with contributions from magmatic water and CO<sub>2</sub> derived by dolomite decarbonation. In general, the Kavokta deposit is a typical dolomite-related nephrite deposit, and the formation of nephrite at the contact between the granitoids and dolomitic marble resulted in the retention of some relic minerals from the granitoids and the crystallization of multiple generations of minerals of various sizes. We propose a model of n
软玉主要由细粒透闪石-放光石聚集体组成，通常产于花岗岩/花岗闪长岩与白云岩大理岩的接触处。以往的研究大多集中在软玉矿床的矿物学、地球化学、年龄和成矿流体等方面。然而，软玉的详细形成过程尚不清楚，特别是软玉中是否存在细粒透闪石聚集体，以及花岗岩类是否可以直接被软玉取代。Kavokta软玉矿床是俄罗斯最大的白云岩相关软玉矿床，是研究软玉矿床形成的理想目标，因为它含有花岗岩类的遗迹矿物组合和软玉形成过程中结晶的多代矿物。本研究采用背散射电子（BSE）成像、TESCAN综合矿物分析（TIMA）、x射线荧光光谱（XRF）、电感耦合等离子体质谱（ICP-MS）、电子探针显微分析（EPMA）、激光烧蚀电感耦合等离子体质谱（LA-ICP-MS）和同位素比值质谱（IRMS）等方法，对Kavokta软玉矿床的成因进行了全面的观察和分析。软玉中的火成岩矿物（磷灰石、allanite、钛矿、钍矿、金红石、钛铁矿）是成矿流体对花岗岩类交代作用后的遗迹。软玉中的残余火成岩矿物，连同交代的透辉石和透辉石，以及其他多阶段矿物组合（如绿帘石、透闪石、滑石、蛇纹石-滑石、辉绿石-绿泥石、透闪石-滑石），记录了岩浆、接触变质、进、退交代阶段。这表明，软玉与细粒透闪石是由粗粒透闪石聚集体相继取代而形成的。绿色和白色软玉样品具有相似的稀土和微量元素特征，其特征为中度负Eu异常，U富集，Nb耗竭。热液锆石赋存于靠近花岗岩寄主的绿软玉中。样品的全岩Zr含量分别为43和31 ppm，锆石的206Pb/238U年龄为343.9±1.2 Ma (n = 10, MSWD = 2.3)，与围岩花岗岩年龄相近。氧、氢同位素资料表明，成矿流体以大气降水为主，岩浆水和白云岩脱碳产生的CO2也很可能对成矿流体有贡献。总的来说，Kavokta矿床是一个典型的与白云岩有关的软玉矿床，软玉形成于花岗岩类与白云岩大理岩的接触处，导致花岗岩类中的一些残留矿物被保留下来，形成了多代大小不一的矿物结晶。我们提出了一种软玉形成模型，其中花岗岩和白云岩大理岩均被成矿流体交代，导致软玉形成，随后粗粒透闪石再结晶为细粒软玉。
{"title":"Genesis of nephrite-bearing magnesian skarns in the Kavokta deposit, Vitim region, eastern Buryatia, Russia: Evidence from petrography, geochemistry, and zircon U–Pb ages and δ18O values","authors":"Yuting Yang , Xiaoxue Lu , Evgeniy V. Kislov , Feng Bai , Yan Liu","doi":"10.1016/j.oregeorev.2025.107016","DOIUrl":"10.1016/j.oregeorev.2025.107016","url":null,"abstract":"<div><div>Nephrite consists predominantly of fine-grained tremolite–actinolite aggregates and typically occurs at the contact between granite/granodiorite and dolomitic marble. Most previous studies have focused on the mineralogy, geochemistry, age, and ore-forming fluids of nephrite deposits. However, the detailed formation processes of nephrite remain unclear, particularly in terms of the occurrence of fine-grained tremolite aggregates in nephrite and whether granitoids can be directly replaced by nephrite. The Kavokta nephrite deposit is the largest dolomite-related nephrite deposit in Russia and is an ideal target for investigating the formation of nephrite deposits because it contains a relic mineral assemblage derived from granitoids and multiple generations of minerals that crystallized during nephrite formation. In this study, we undertook a comprehensive set of observations and analyses, including back-scattered electron (BSE) imaging, TESCAN integrated mineral analysis (TIMA), X-ray fluorescence spectrometry (XRF), inductively coupled plasma–mass spectrometry (ICP–MS), electron probe microanalysis (EPMA), laser ablation inductively coupled plasma–mass spectrometry (LA–ICP–MS), and isotope ratio mass spectrometry (IRMS), to constrain the genesis of the Kavokta nephrite deposit. The igneous minerals (e.g., apatite, allanite, titanite, thorite, rutile and ilmenite) in the nephrite are relics after metasomatism of the granitoids by ore-forming fluids. The relic igneous minerals, along with the metasomatic grossular and diopside, and other multi-stage mineral assemblages (e.g., epidote, tremolite, and talc; serpentine–talc; phlogopite–chlorite; tremolite–chlorite; and tremolite–talc) in the nephrite, record magmatic, contact metamorphic, and prograde and retrograde metasomatic stages. This suggests that the nephrite with fine-grained tremolite formed by the successive replacement of coarse-grained tremolite aggregates. Both green and white nephrite samples have similar rare earth and trace element features, characterized by moderate negative Eu anomalies, U enrichment, and Nb depletion. Hydrothermal zircons occur in two samples of green nephrite collected near the host granitoids. The samples have whole-rock Zr contents of 43 and 31 ppm, and the zircons yield a concordant <sup>206</sup>Pb/<sup>238</sup>U age of 343.9 ± 1.2 Ma (n = 10; MSWD = 2.3), similar to the age of the host granitoids. Oxygen and hydrogen isotope data indicate the ore-forming fluids in this deposit were predominantly meteoric water, very possibly with contributions from magmatic water and CO<sub>2</sub> derived by dolomite decarbonation. In general, the Kavokta deposit is a typical dolomite-related nephrite deposit, and the formation of nephrite at the contact between the granitoids and dolomitic marble resulted in the retention of some relic minerals from the granitoids and the crystallization of multiple generations of minerals of various sizes. We propose a model of n","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107016"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107029
Tingwei Liu , Guoxu Chen , Yufeng Deng , Shengxuan Cao , Huqiang Wang , Xuewen Zhang
Constructing complex geological models is one of the core tasks in geosciences. This study proposes an implicit modeling approach that integrates data-driven techniques with prior geological knowledge. The approach is designed to address challenges such as data sparsity, morphological complexity, and inadequate uncertainty representation in the three-dimensional modeling of complex Cu-Ni sulfide orebodies. The method extracts point sets from multi-directional two-dimensional sectional contours and utilizes Chamfer distance-based hard constraints to characterize the geometric features of orebody boundaries. A geochemical grade field is constructed using Kriging interpolation, while a mineralization probability field is generated through a logistic regression model to provide soft constraints that guide boundary evolution. The orebody interfaces are dynamically evolved using a level set function, and multiple realizations are generated through Markov Chain Monte Carlo sampling, effectively capturing the complexity and spatial variability inherent in the mineralization process. A multi-source loss function is developed to simultaneously enhance geometric accuracy and incorporate mineralization trend information, thereby improving the model’s structural validity and spatial continuity. Applying the proposed method to the Tulaergen and Huangshanxi Cu-Ni sulfide deposits in the Eastern Tianshan region of Xinjiang demonstrates its applicability and robustness in modeling complex orebodies and representing multiple solution scenarios. This provides robust technical support for deep resource evaluation, uncertainty quantification, and exploration decision-making.
{"title":"Data–knowledge integrated stochastic modeling of complex Cu-Ni sulfide orebodies: A case study from the Eastern Tianshan Cu-Ni Deposit, Xinjiang, China","authors":"Tingwei Liu , Guoxu Chen , Yufeng Deng , Shengxuan Cao , Huqiang Wang , Xuewen Zhang","doi":"10.1016/j.oregeorev.2025.107029","DOIUrl":"10.1016/j.oregeorev.2025.107029","url":null,"abstract":"<div><div>Constructing complex geological models is one of the core tasks in geosciences. This study proposes an implicit modeling approach that integrates data-driven techniques with prior geological knowledge. The approach is designed to address challenges such as data sparsity, morphological complexity, and inadequate uncertainty representation in the three-dimensional modeling of complex Cu-Ni sulfide orebodies. The method extracts point sets from multi-directional two-dimensional sectional contours and utilizes Chamfer distance-based hard constraints to characterize the geometric features of orebody boundaries. A geochemical grade field is constructed using Kriging interpolation, while a mineralization probability field is generated through a logistic regression model to provide soft constraints that guide boundary evolution. The orebody interfaces are dynamically evolved using a level set function, and multiple realizations are generated through Markov Chain Monte Carlo sampling, effectively capturing the complexity and spatial variability inherent in the mineralization process. A multi-source loss function is developed to simultaneously enhance geometric accuracy and incorporate mineralization trend information, thereby improving the model’s structural validity and spatial continuity. Applying the proposed method to the Tulaergen and Huangshanxi Cu-Ni sulfide deposits in the Eastern Tianshan region of Xinjiang demonstrates its applicability and robustness in modeling complex orebodies and representing multiple solution scenarios. This provides robust technical support for deep resource evaluation, uncertainty quantification, and exploration decision-making.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107029"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107021
Miao Shi , Qinyuan Cao , Jinchuan Zhang , Ye Yuan , Haoyu Lu , Xiwei Wang
The redox conditions of seawater in the shallow-water to deep-water facies of the Early Cambrian Niutitang Formation exhibited significant differences, which controlled the deposition of black shales. These conditions further affect the porosity of shale, and the evolution of pores is also influenced by subsequent diagenesis, thus leading to a close correlation with the mechanism of shale gas accumulation. In this study, shale samples from the Niutitang Formation in Well Cenye–1 (CY–1), Cengong region, Guizhou Province, were analyzed to reconstruct paleoredox conditions and their impact on shale gas enrichment. An integrated approach combining pyrite morphology, Fe speciation, and Fe–S isotope geochemistry was employed. The research shows three primary morphological types of pyrite: framboidal, euhedral to subhedral, and anhedral (typically amorphous in nature). These different types of pyrite indicate distinct sedimentary environments. Framboidal pyrite indicates a ferruginous-euxinic environment, euhedral to subhedral pyrite suggests an euxinic environment, and anhedral pyrite implies hydrothermal activity during shale deposition. The FeHR/FeT ratios (0.68–0.99) and Fepy/FeHR ratios (0.7–0.98) both indicate that the predominant sedimentary environment was euxinic. The δ56Fe values (0.31‰ to 1.57‰) exhibit a distinct positive drift, while the δ34Spyvalues (−7.76‰ to 17.05‰) display a significant negative drift. The Fe–S isotope trends further confirm that the Niutitang Formation shale was euxinic sedimentary environment. Pyrite exerts a significant control on the enrichment and preservation of organic matter as the intergranular pores within framboidal pyrite aggregates serve as a carrier for the adsorption, preservation, and migration of shale gas. In an euxinic environment, weaker hydrodynamic conditions combined with a more reducing sedimentary environment are more favorable for the preservation of organic matter in shale gas reservoirs, resulting in an increased amount of generated and expelled hydrocarbons. This study systematically elucidates the critical role of pyrite in indicating the depositional environment of shale and the shale gas enrichment process. It provides an important theoretical foundation and key geochemical indicators for optimizing exploration targets in structurally complex regions.
{"title":"Decoding paleoredox environments and shale gas accumulation in the Niutitang Formation (South China): A pyrite morphology, Fe speciation, and Fe–S isotopes perspective","authors":"Miao Shi , Qinyuan Cao , Jinchuan Zhang , Ye Yuan , Haoyu Lu , Xiwei Wang","doi":"10.1016/j.oregeorev.2025.107021","DOIUrl":"10.1016/j.oregeorev.2025.107021","url":null,"abstract":"<div><div>The redox conditions of seawater in the shallow-water to deep-water facies of the Early Cambrian Niutitang Formation exhibited significant differences, which controlled the deposition of black shales. These conditions further affect the porosity of shale, and the evolution of pores is also influenced by subsequent diagenesis, thus leading to a close correlation with the mechanism of shale gas accumulation. In this study, shale samples from the Niutitang Formation in Well Cenye–1 (CY–1), Cengong region, Guizhou Province, were analyzed to reconstruct paleoredox conditions and their impact on shale gas enrichment. An integrated approach combining pyrite morphology, Fe speciation, and Fe–S isotope geochemistry was employed. The research shows three primary morphological types of pyrite: framboidal, euhedral to subhedral, and anhedral (typically amorphous in nature). These different types of pyrite indicate distinct sedimentary environments. Framboidal pyrite indicates a ferruginous-euxinic environment, euhedral to subhedral pyrite suggests an euxinic environment, and anhedral pyrite implies hydrothermal activity during shale deposition. The Fe<sub>HR</sub>/Fe<sub>T</sub> ratios (0.68–0.99) and Fe<sub>py</sub>/Fe<sub>HR</sub> ratios (0.7–0.98) both indicate that the predominant sedimentary environment was euxinic. The <em>δ</em><sup>56</sup>Fe values (0.31‰ to 1.57‰) exhibit a distinct positive drift, while the <em>δ</em><sup>34</sup>S<sub>py</sub>values (−7.76‰ to 17.05‰) display a significant negative drift. The Fe–S isotope trends further confirm that the Niutitang Formation shale was euxinic sedimentary environment. Pyrite exerts a significant control on the enrichment and preservation of organic matter as the intergranular pores within framboidal pyrite aggregates serve as a carrier for the adsorption, preservation, and migration of shale gas. In an euxinic environment, weaker hydrodynamic conditions combined with a more reducing sedimentary environment are more favorable for the preservation of organic matter in shale gas reservoirs, resulting in an increased amount of generated and expelled hydrocarbons. This study systematically elucidates the critical role of pyrite in indicating the depositional environment of shale and the shale gas enrichment process. It provides an important theoretical foundation and key geochemical indicators for optimizing exploration targets in structurally complex regions.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107021"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107035
Gai-Zhong Liang , Hong-Rui Fan , Sheng-Peng Du , Zhao-Wei Zhang , Guang-Li Ren , Xing-Hui Li , Kui-Feng Yang , Qing-Dong Zeng , Jin-Jian Wu
The Gouli goldfield, hosting intense magmatism related gold mineralization, is a highly distinctive gold producer in the East Kunlun Orogenic Belt. Genesis of gold deposits in this region is enigmatic, primarily due to uncertainties of the ore-forming timing, the critical mineralization processes and the material sources. Here, we conducted comprehensive in-situ textural and geochemistry (trace elements, mapping and sulfur isotopes) analyses on pyrite and in-situ U-Pb dating on monazite from the hydrothermal stages in Walega gold deposit from the north-central Gouli goldfield, with the aim to exactly constrain these uncertainties. Three types of pyrite are classified in the Walega gold deposit, based on their structural and geochemical characteristics. Py1 is mostly found in pyrite-quartz veins (metallogenic stage I), and often occurs as the nucleus of Py2 and Py3 in stages II or III, or is replaced by transitional pyrite (T-Py) or Py2. T-Py, a nano-micron pyrite particle aggregate, is the transition pyrite between Py1 and Py2, and usually shows colloidal, pseudocrystalline, and banded textures. Py2 is mainly found in pyrite-arsenopyrite-quartz veins (metallogenic stage II), which has a close syngenetic relationship with the arsenopyrite, and is commonly found as core (Py1)-rim (Py2) structure. Py3 is mainly found in quartz-polymetallic sulphide veins (metallogenic stage III), as a common core (Py1)-mantle (Py2)-rim (Py3) structure. In metallogenic stage III, the darkest pyrite (Py1) is encapsulated by brighter pyrite (Py2) co-precipitated with gold and arsenopyrite, and the brighter pyrite (Py2) is encapsulated by the brightest pyrite (Py3) co-precipitated with polymetallic minerals. Py1 typically contains lower concentrations of As (median 11.97 ppm) and Au (median 0.02 ppm), with δ34S values ranging from + 4.0 ‰ to + 6.1 ‰. Py2 exhibits the highest concentrations of As (median 7559 ppm) and the second-highest concentrations of Au (median 1.86 ppm), with δ34S values (+4.0 ‰ to + 5.9 ‰) similar to those of Py1 and Py3. T-Py shows the second-highest As content (median 1871 ppm) but the highest Au content (median 2.86 ppm). The As and Au contents of Py3 fall between those of Py1 and Py2, and its δ34S values ranging from + 4.4 ‰ to + 6.2 ‰. U-Pb dating of hydrothermal monazite in metallogenic stage I and III constrains the mineralization age to ∼ 229 Ma, consistent with the age of magmatic-hydrothermal gold mineralization of Gouli goldfield. The chemical composition and structural characteristics of pyrite, along with monazite geochronology, suggest that the ore-forming fluids in the Walega gold deposit are derived from multistage magmatic-hydrothermal processes and that both the fluids and ore-forming materials originated from the late hydrothermal phase of the granitic magmatism.
{"title":"Geochronology, ore-forming processes and metal source of the Walega gold deposit, Eastern Kunlun Orogenic Belt, China: Constraints from monazite in-situ U-Pb dating and pyrite geochemistry","authors":"Gai-Zhong Liang , Hong-Rui Fan , Sheng-Peng Du , Zhao-Wei Zhang , Guang-Li Ren , Xing-Hui Li , Kui-Feng Yang , Qing-Dong Zeng , Jin-Jian Wu","doi":"10.1016/j.oregeorev.2025.107035","DOIUrl":"10.1016/j.oregeorev.2025.107035","url":null,"abstract":"<div><div>The Gouli goldfield, hosting intense magmatism related gold mineralization, is a highly distinctive gold producer in the East Kunlun Orogenic Belt. Genesis of gold deposits in this region is enigmatic, primarily due to uncertainties of the ore-forming timing, the critical mineralization processes and the material sources. Here, we conducted comprehensive in-situ textural and geochemistry (trace elements, mapping and sulfur isotopes) analyses on pyrite and in-situ U-Pb dating on monazite from the hydrothermal stages in Walega gold deposit from the north-central Gouli goldfield, with the aim to exactly constrain these uncertainties. Three types of pyrite are classified in the Walega gold deposit, based on their structural and geochemical characteristics. Py1 is mostly found in pyrite-quartz veins (metallogenic stage I), and often occurs as the nucleus of Py2 and Py3 in stages II or III, or is replaced by transitional pyrite (T-Py) or Py2. T-Py, a nano-micron pyrite particle aggregate, is the transition pyrite between Py1 and Py2, and usually shows colloidal, pseudocrystalline, and banded textures. Py2 is mainly found in pyrite-arsenopyrite-quartz veins (metallogenic stage II), which has a close syngenetic relationship with the arsenopyrite, and is commonly found as core (Py1)-rim (Py2) structure. Py3 is mainly found in quartz-polymetallic sulphide veins (metallogenic stage III), as a common core (Py1)-mantle (Py2)-rim (Py3) structure. In metallogenic stage III, the darkest pyrite (Py1) is encapsulated by brighter pyrite (Py2) co-precipitated with gold and arsenopyrite, and the brighter pyrite (Py2) is encapsulated by the brightest pyrite (Py3) co-precipitated with polymetallic minerals. Py1 typically contains lower concentrations of As (median 11.97 ppm) and Au (median 0.02 ppm), with δ<sup>34</sup>S values ranging from + 4.0 ‰ to + 6.1 ‰. Py2 exhibits the highest concentrations of As (median 7559 ppm) and the second-highest concentrations of Au (median 1.86 ppm), with δ<sup>34</sup>S values (+4.0 ‰ to + 5.9 ‰) similar to those of Py1 and Py3. T-Py shows the second-highest As content (median 1871 ppm) but the highest Au content (median 2.86 ppm). The As and Au contents of Py3 fall between those of Py1 and Py2, and its δ<sup>34</sup>S values ranging from + 4.4 ‰ to + 6.2 ‰. U-Pb dating of hydrothermal monazite in metallogenic stage I and III constrains the mineralization age to ∼ 229 Ma, consistent with the age of magmatic-hydrothermal gold mineralization of Gouli goldfield. The chemical composition and structural characteristics of pyrite, along with monazite geochronology, suggest that the ore-forming fluids in the Walega gold deposit are derived from multistage magmatic-hydrothermal processes and that both the fluids and ore-forming materials originated from the late hydrothermal phase of the granitic magmatism.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107035"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.oregeorev.2025.107032
Zenglian Xu , Chao Tang , Huajian Liu , Ming Duan
The Luhai uranium deposit is a typical paleo-channel sandstone-type uranium deposit. Its target layer is the upper section of the SaihanTala Formation (K1s3), deposited in a fluvial environment. However, the unclear relationship between sedimentary facies, sequence stratigraphy, and uranium mineralization hinders subsequent prospecting and prediction. A comprehensive analysis of this relationship between sequence and sedimentary facies and uranium mineralization led to the development of a sequence-sedimentation-mineralization model, exploring the law of uranium mineralization. One third-order sequences (SQ) were identified in K1s3 of the Erlian Basin, comprising a lowstand systems tract (LST), transgressive systems tract (TST), and highstand systems tract (HST). The target layer exhibited five subfacies and eight microfacies in the braided and meandering river facies. Uranium mineralization was predominantly concentrated in braided channel sediments formed durirng the LST. Notably, thick and stable uranium mineralization was observed at the transition from channel lag microfacies to channel bar microfacies or from channel bar microfacies to floodplain microfacies. During the early K1s3 period, fault-depression transition activity and a warm-humid climate controlled the development of charcoal-rich braided channel sand bodies in the LST. During the late K1s3 period, red mudstone interbedded with sandstone was deposited in the TST and HST. This, combined with the sand bodies formed in the LST of K1s3 and thick lacustrine mudstone deposited in the K2s2, resulted in a mud-sand-mud structure conducive to uranium enrichment. During the K2-E1 period, enhanced tectonic uplift facilitated the migration of uranium-bearing fluids along steep paleo topography towards the charcoal-rich geochemical barrier, contributing to the reductive mineralization in the channel bar deposits. Our findings illustrate the importance of sequence stratigraphy and sedimentary facies in sandstone-type uranium mineralization of fluvial deposits. This research provides valuable insights and guidance for future prospecting and predictive modeling of such uranium deposits.
{"title":"The relationship between sedimentary facies and sequence stratigraphy of SaihanTala Formation and sandstone-type mineralization in the Luhai uranium deposit of Erlian Basin","authors":"Zenglian Xu , Chao Tang , Huajian Liu , Ming Duan","doi":"10.1016/j.oregeorev.2025.107032","DOIUrl":"10.1016/j.oregeorev.2025.107032","url":null,"abstract":"<div><div>The Luhai uranium deposit is a typical paleo-channel sandstone-type uranium deposit. Its target layer is the upper section of the SaihanTala Formation (K<sub>1</sub>s<sup>3</sup>), deposited in a fluvial environment. However, the unclear relationship between sedimentary facies, sequence stratigraphy, and uranium mineralization hinders subsequent prospecting and prediction. A comprehensive analysis of this relationship between sequence and sedimentary facies and uranium mineralization led to the development of a sequence-sedimentation-mineralization model, exploring the law of uranium mineralization. One third-order sequences (SQ) were identified in K<sub>1</sub>s<sup>3</sup> of the Erlian Basin, comprising a lowstand systems tract (LST), transgressive systems tract (TST), and highstand systems tract (HST). The target layer exhibited five subfacies and eight microfacies in the braided and meandering river facies. Uranium mineralization was predominantly concentrated in braided channel sediments formed durirng the LST. Notably, thick and stable uranium mineralization was observed at the transition from channel lag microfacies to channel bar microfacies or from channel bar microfacies to floodplain microfacies. During the early K<sub>1</sub>s<sup>3</sup> period, fault-depression transition activity and a warm-humid climate controlled the development of charcoal-rich braided channel sand bodies in the LST. During the late K<sub>1</sub>s<sup>3</sup> period, red mudstone interbedded with sandstone was deposited in the TST and HST. This, combined with the sand bodies formed in the LST of K<sub>1</sub>s<sup>3</sup> and thick lacustrine mudstone deposited in the K<sub>2</sub>s<sup>2</sup>, resulted in a mud-sand-mud structure conducive to uranium enrichment. During the K<sub>2</sub>-E<sub>1</sub> period, enhanced tectonic uplift facilitated the migration of uranium-bearing fluids along steep paleo topography towards the charcoal-rich geochemical barrier, contributing to the reductive mineralization in the channel bar deposits. Our findings illustrate the importance of sequence stratigraphy and sedimentary facies in sandstone-type uranium mineralization of fluvial deposits. This research provides valuable insights and guidance for future prospecting and predictive modeling of such uranium deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107032"},"PeriodicalIF":3.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The seismic reflection method enables the interpretation of ore-controlling structures across various scales that govern ore-forming processes, facilitating the establishment of high-resolution deep prospecting models. Despite significant advances in exploring targets across various scales, from ore districts to deposits and bodies, a systematic prospecting framework is still lacking. Based on mineral systems theory, this study reviews the seismic wave response characteristics from existing global seismic exploration cases to develop a systematic prospecting model that correlates specific seismic frequency domains with the four fundamental elements of the mineral system: source-transport-trap-preservation. The model employs multi-band seismic reflection technologies to characterize ore-forming elements at corresponding scales. Low-frequency seismic data (<20 Hz) can effectively image large-scale lithospheric structures that control metal enrichment processes, such as the crust-mantle boundary and deep-seated magma chambers, thereby constraining potential source regions for ore-forming materials. Medium- to low-frequency seismic data (20–40 Hz) can interpret the fault networks and unconformity surfaces that channelize fluids migration, thus analyzing key transport pathways for ore-forming fluids. Medium- to high-frequency seismic data (40–60 Hz) can identify ore-hosting structures and lithological contacts, defining deposition traps for metal precipitation. High-frequency seismic data (>60 Hz) can delineate the preservation sites of ore bodies or mineralized alteration zones. This model may offer significant potential for guiding deep mineral exploration. As seismic exploration technologies for metallic minerals continue to advance and multi-technique integration constraints strengthen, its predictive accuracy and exploration efficiency will be substantially enhanced.
{"title":"A multi-frequency seismic reflection prospecting model for metallic mineral exploration based on the mineral system: A review","authors":"Zhe Zhou , Weiwei Zhou , Wengao Zhang , Tengfei Wang","doi":"10.1016/j.oregeorev.2025.107030","DOIUrl":"10.1016/j.oregeorev.2025.107030","url":null,"abstract":"<div><div>The seismic reflection method enables the interpretation of ore-controlling structures across various scales that govern ore-forming processes, facilitating the establishment of high-resolution deep prospecting models. Despite significant advances in exploring targets across various scales, from ore districts to deposits and bodies, a systematic prospecting framework is still lacking. Based on mineral systems theory, this study reviews the seismic wave response characteristics from existing global seismic exploration cases to develop a systematic prospecting model that correlates specific seismic frequency domains with the four fundamental elements of the mineral system: source-transport-trap-preservation. The model employs multi-band seismic reflection technologies to characterize ore-forming elements at corresponding scales. Low-frequency seismic data (<20 Hz) can effectively image large-scale lithospheric structures that control metal enrichment processes, such as the crust-mantle boundary and deep-seated magma chambers, thereby constraining potential source regions for ore-forming materials. Medium- to low-frequency seismic data (20–40 Hz) can interpret the fault networks and unconformity surfaces that channelize fluids migration, thus analyzing key transport pathways for ore-forming fluids. Medium- to high-frequency seismic data (40–60 Hz) can identify ore-hosting structures and lithological contacts, defining deposition traps for metal precipitation. High-frequency seismic data (>60 Hz) can delineate the preservation sites of ore bodies or mineralized alteration zones. This model may offer significant potential for guiding deep mineral exploration. As seismic exploration technologies for metallic minerals continue to advance and multi-technique integration constraints strengthen, its predictive accuracy and exploration efficiency will be substantially enhanced.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107030"},"PeriodicalIF":3.6,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The South Altai in the Central Asian Orogenic Belt (CAOB) contains four Devonian-Carboniferous extensional volcano-sedimentary basins: Ashele, Chonghu'er, Kelan, and Maizi. Three basins (Ashele, Kelan, Maizi) host subduction-related arc/back-arc magmatism and significant volcanogenic massive sulfide (VMS) deposits. However, the Chonghuer Basin, which hosts the Keyinbulake Zn-Cu deposit, lacks a well-established genetic link to regional submarine volcanism. Combining sulfur isotopes and trace element geochemistry of sulfides, we identify two distinct mineralization stages: (1) syngenetic massive Zn-Cu mineralization (362–380 °C) driven by magmatic-hydrothermal fluids enriched in Cu, Se, and Bi, and (2) epigenetic vein-type Zn-Pb mineralization (338–367 °C) dominated by seawater-derived fluids influenced by phase separation. Sulfur isotopes (δ34S = +0.84 ‰ to + 3.61 ‰) confirm sulfur derivation via thermochemical sulfate reduction (TSR) of marine sulfate, with minimal magmatic input. The syngenetic stage (Py1 and Sp1) is characterized by coarse-grained pyrite enriched in Cu, Se, and Bi, and sphalerite with elevated Fe, Mn, Cu and In, demonstrating the key role of magmatic volatiles in early metal mobilization. In contrast, the epigenetic stage features higher Co/Ni in pyrite (Py2), low-In sphalerite (Sp2), reflecting seawater-dominated fluids modified by phase separation at lower temperatures. This study highlights the dynamic interplay between magmatic and seawater-derived fluids, where early magmatic inputs and later seawater-dominated processes collectively govern polymetallic enrichment. This work establishes Keyinbulake as a hybrid seafloor hydrothermal system in CAOB, governed by early magmatic contributions and later seawater-driven processes to enrich polymetallic ores.
{"title":"Magmatic-seawater interaction in the Keyinbulake Zn-Cu deposit (NW China): Insight from sulfide S isotope and trace elements","authors":"Wendong Zhang, Xuebing Zhang, Guangfei Liu, Xulun Guo","doi":"10.1016/j.oregeorev.2025.107027","DOIUrl":"10.1016/j.oregeorev.2025.107027","url":null,"abstract":"<div><div>The South Altai in the Central Asian Orogenic Belt (CAOB) contains four Devonian-Carboniferous extensional volcano-sedimentary basins: Ashele, Chonghu'er, Kelan, and Maizi. Three basins (Ashele, Kelan, Maizi) host subduction-related arc/back-arc magmatism and significant volcanogenic massive sulfide (VMS) deposits. However, the Chonghuer Basin, which hosts the Keyinbulake Zn-Cu deposit, lacks a well-established genetic link to regional submarine volcanism. Combining sulfur isotopes and trace element geochemistry of sulfides, we identify two distinct mineralization stages: (1) syngenetic massive Zn-Cu mineralization (362–380 °C) driven by magmatic-hydrothermal fluids enriched in Cu, Se, and Bi, and (2) epigenetic vein-type Zn-Pb mineralization (338–367 °C) dominated by seawater-derived fluids influenced by phase separation. Sulfur isotopes (δ<sup>34</sup>S = +0.84 ‰ to + 3.61 ‰) confirm sulfur derivation via thermochemical sulfate reduction (TSR) of marine sulfate, with minimal magmatic input. The syngenetic stage (Py1 and Sp1) is characterized by coarse-grained pyrite enriched in Cu, Se, and Bi, and sphalerite with elevated Fe, Mn, Cu and In, demonstrating the key role of magmatic volatiles in early metal mobilization. In contrast, the epigenetic stage features higher Co/Ni in pyrite (Py2), low-In sphalerite (Sp2), reflecting seawater-dominated fluids modified by phase separation at lower temperatures. This study highlights the dynamic interplay between magmatic and seawater-derived fluids, where early magmatic inputs and later seawater-dominated processes collectively govern polymetallic enrichment. This work establishes Keyinbulake as a hybrid seafloor hydrothermal system in CAOB, governed by early magmatic contributions and later seawater-driven processes to enrich polymetallic ores.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107027"},"PeriodicalIF":3.6,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-28DOI: 10.1016/j.oregeorev.2025.107028
Jianfang Zhang , Changgui Xiao , Haoran Chen , Zhen Wang , Yanhua Hu , Kunlun Zhang , Zhili Ma , Huidong Yu , Gangyang Zhang , Hao Zou , Huawen Cao
Large-scale fluorite mineralization occurred in the South China Block during the Late Cretaceous, but its genesis and tectonic setting remain unknown. The Hengkengping fluorite deposit, a representative large-scale hydrothermal vein-type monomineralic fluorite deposit in the Zhezhong–Wuyi minerogenetic belt in South China, is characterized by high-grade ore and substantial reserves. Most orebodies occur in NE-trending fractures within early Cretaceous porphyroclastic lava controlled by NE-striking faults along Mesozoic volcanic faulted basins. In this study, the timing and genesis of mineralization were systematically investigated through integrated methods, including cathodoluminescence imaging, fluid inclusion microthermometry, in situ laser ablation inductively coupled plasma mass spectroscopy (LA–ICP–MS) microanalysis, H–O isotope tracing, and Sm–Nd isotope dating. Ore textures and cathodoluminescence features revealed the following three mineral types (stages): purple veinlet/breccia-type fluorite, green massive fluorite, and colorless vein-replacement fluorite. The trace and rare earth element signatures of fluorite indicated a multistage growth history involving dissolution–reprecipitation–recrystallization, with characteristics of homologous medium- to low-temperature hydrothermal products. Sm–Nd isochron dating yielded an age of 80 ± 3 Ma, which coincides with terminal Late Cretaceous volcanism. The low εNd(80 Ma) values suggested crustal derivation of ore-forming materials. The δD and δ18O values of the ore-forming fluids indicated dominant meteoric water involvement. The fluid inclusion data revealed homogenization temperatures ranging from 100 to 190 °C and the occurrence of low-salinity H2O–NaCl fluids, corresponding to a shallow mineralization depth (∼0.9 km). The ore-forming system involved geothermal fluids derived from deeply circulated meteoric water heated by Cretaceous magmatic activity. Water–rock interactions between geothermal fluids and F-rich volcanic rocks generated weakly reduced, F-enriched medium- to low-temperature hydrothermal fluids. These F-bearing fluids, mobilized from Jurassic–Cretaceous pyroclastic sequences, precipitated large-scale fluorite deposits through cooling and decompression during their ascent along fault zones. In this study, it is proposed that Late Cretaceous extensional tectonics and volcanism, driven by Paleo-Pacific Plate rollback, provided critical controls on the surge in fluorite mineralization in the South China Block by providing F-rich materials, thermal energy, fluid dynamics, and structural traps for the formation of fluorite deposits.
{"title":"Genesis of the Late Cretaceous fluorite mineralization surge in Zhejiang, South China, using geochronological, isotopic, and geochemical evidence from the Hengkengping fluorite deposit","authors":"Jianfang Zhang , Changgui Xiao , Haoran Chen , Zhen Wang , Yanhua Hu , Kunlun Zhang , Zhili Ma , Huidong Yu , Gangyang Zhang , Hao Zou , Huawen Cao","doi":"10.1016/j.oregeorev.2025.107028","DOIUrl":"10.1016/j.oregeorev.2025.107028","url":null,"abstract":"<div><div>Large-scale fluorite mineralization occurred in the South China Block during the Late Cretaceous, but its genesis and tectonic setting remain unknown. The Hengkengping fluorite deposit, a representative large-scale hydrothermal vein-type monomineralic fluorite deposit in the Zhezhong–Wuyi minerogenetic belt in South China, is characterized by high-grade ore and substantial reserves. Most orebodies occur in NE-trending fractures within early Cretaceous porphyroclastic lava controlled by NE-striking faults along Mesozoic volcanic faulted basins. In this study, the timing and genesis of mineralization were systematically investigated through integrated methods, including cathodoluminescence imaging, fluid inclusion microthermometry, in situ laser ablation inductively coupled plasma mass spectroscopy (LA–ICP–MS) microanalysis, H–O isotope tracing, and Sm–Nd isotope dating. Ore textures and cathodoluminescence features revealed the following three mineral types (stages): purple veinlet/breccia-type fluorite, green massive fluorite, and colorless vein-replacement fluorite. The trace and rare earth element signatures of fluorite indicated a multistage growth history involving dissolution–reprecipitation–recrystallization, with characteristics of homologous medium- to low-temperature hydrothermal products. Sm–Nd isochron dating yielded an age of 80 ± 3 Ma, which coincides with terminal Late Cretaceous volcanism. The low εNd<sub>(80 Ma)</sub> values suggested crustal derivation of ore-forming materials. The δD and δ<sup>18</sup>O values of the ore-forming fluids indicated dominant meteoric water involvement. The fluid inclusion data revealed homogenization temperatures ranging from 100 to 190 °C and the occurrence of low-salinity H<sub>2</sub>O–NaCl fluids, corresponding to a shallow mineralization depth (∼0.9 km). The ore-forming system involved geothermal fluids derived from deeply circulated meteoric water heated by Cretaceous magmatic activity. Water–rock interactions between geothermal fluids and F-rich volcanic rocks generated weakly reduced, F-enriched medium- to low-temperature hydrothermal fluids. These F-bearing fluids, mobilized from Jurassic–Cretaceous pyroclastic sequences, precipitated large-scale fluorite deposits through cooling and decompression during their ascent along fault zones. In this study, it is proposed that Late Cretaceous extensional tectonics and volcanism, driven by Paleo-Pacific Plate rollback, provided critical controls on the surge in fluorite mineralization in the South China Block by providing F-rich materials, thermal energy, fluid dynamics, and structural traps for the formation of fluorite deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107028"},"PeriodicalIF":3.6,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dynamic interplay between melt evolution and fluid activity plays a crucial role in rare metal enrichment in highly fractionated granites, yet the specific mechanisms remain inadequately understood. This study explores the recently discovered Tailaihua Be–Nb–Ta deposit in the southern Great Xing’an Range (SGXR) to elucidate these processes. By integrating monazite U–Pb geochronology, whole-rock geochemistry, and electron probe microanalysis (EPMA) of major minerals, we establish a comprehensive magmatic-hydrothermal evolution sequence and explores the behavioral dynamics of melt-fluid interactions within highly fractionated granitic systems exhibiting Be-Nb-Ta mineralization. LA-ICP-MS U-Pb dating of Tailaihua ore-forming granite yielded ages of 143.4 ± 1.9 Ma for the monzonitic granite (MG), 142.1 ± 2.3 Ma for the alkali-feldspathic granite (AFG), and 140.0 ± 3.0 Ma for the albite granite (AG). The Tailaihua ore-forming granites are characterized by high SiO2, Al2O3, alkalis (K2O + Na2O), and A/CNK ratios (>1.1), with depleted CaO, MgO, FeOT, indicating high-K peraluminous compositions. Trace elements show Rb-Th-U-Ta enrichment and Sr-Ba-Eu depletion, confirming highly fractionated I-type granitic magmas, accompanied by strongly REE tetrad effects. Progressive crystal fractionation of biotite, K-feldspar, and plagioclase within the MG-AFG-AG sequence drove magma evolution. Our key finding reveals that extreme rare metal enrichment resulted from a two-stage process: 1) initial magmatic concentration through fractional crystallization, followed by 2) significant hydrothermal remobilization driven by volatile exsolution (H2O–F), inducing pervasive metasomatism and characteristic REE tetrad effects. This study quantitatively links magma differentiation to ore formation, offering a robust model for exploring similar rare-metal deposits.
{"title":"Petrogenesis of the Tailaihua ore-forming granites in the southern Great Xing’an Range, NE China: Implications for magma evolution and Be-Nb-Ta mineralization in Late Mesozoic","authors":"Jiangpeng Shi , Guang Wu , Gongzheng Chen , Yanjing Chen","doi":"10.1016/j.oregeorev.2025.107008","DOIUrl":"10.1016/j.oregeorev.2025.107008","url":null,"abstract":"<div><div>The dynamic interplay between melt evolution and fluid activity plays a crucial role in rare metal enrichment in highly fractionated granites, yet the specific mechanisms remain inadequately understood. This study explores the recently discovered Tailaihua Be–Nb–Ta deposit in the southern Great Xing’an Range (SGXR) to elucidate these processes. By integrating monazite U–Pb geochronology, whole-rock geochemistry, and electron probe microanalysis (EPMA) of major minerals, we establish a comprehensive magmatic-hydrothermal evolution sequence and explores the behavioral dynamics of melt-fluid interactions within highly fractionated granitic systems exhibiting Be-Nb-Ta mineralization. LA-ICP-MS U-Pb dating of Tailaihua ore-forming granite yielded ages of 143.4 ± 1.9 Ma for the monzonitic granite (MG), 142.1 ± 2.3 Ma for the alkali-feldspathic granite (AFG), and 140.0 ± 3.0 Ma for the albite granite (AG). The Tailaihua ore-forming granites are characterized by high SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, alkalis (K<sub>2</sub>O + Na<sub>2</sub>O), and A/CNK ratios (>1.1), with depleted CaO, MgO, FeO<sup>T</sup>, indicating high-K peraluminous compositions. Trace elements show Rb-Th-U-Ta enrichment and Sr-Ba-Eu depletion, confirming highly fractionated I-type granitic magmas, accompanied by strongly REE tetrad effects. Progressive crystal fractionation of biotite, K-feldspar, and plagioclase within the MG-AFG-AG sequence drove magma evolution. Our key finding reveals that extreme rare metal enrichment resulted from a two-stage process: 1) initial magmatic concentration through fractional crystallization, followed by 2) significant hydrothermal remobilization driven by volatile exsolution (H<sub>2</sub>O–F), inducing pervasive metasomatism and characteristic REE tetrad effects. This study quantitatively links magma differentiation to ore formation, offering a robust model for exploring similar rare-metal deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"188 ","pages":"Article 107008"},"PeriodicalIF":3.6,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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