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[Display omitted] • The Jinkeng deposit formed in two stages (∼147 Ma and ∼141 Ma, respectively). • Different metallogenic potential for the two granitic rocks. • The regional compression occurred in the range of 147–144 Ma. The Jinkeng Sn-Cu polymetallic deposit in South China consists of two different types of orebodies: 1) NE-striking skarn- and vein-type Cu-Pb-Zn-Sn orebodies in volcanic rocks suffering subsequent ductile shear deformation, and 2) NW-striking quartz-cassiterite-sulfide veins filled in the faults at the porphyritic granodiorite outward from the fine-grained granite which does not exhibit deformation. The relationships among Sn-Cu polymetallic mineralization, regional magmatism, and deformation metamorphism are still controversial. To address it, the geochronological, whole-rock and mineral geochemical research along with the detailed field investigation were conducted in this study. Our zircon U-Pb dating results show that the volcanic rocks formed at 158–162 Ma, earlier than the porphyritic granodiorite which yields the emplacement age of 146–147 Ma. In-situ LA-ICP-MS U-Pb dating of cassiterite from the deformed skarn ores indicates the early-stage mineralization occurred at 146 ∼ 148 Ma, which is similar to the emplacement age of the porphyritic granodiorite, but earlier than the formation of quartz-cassiterite-sulfide veins and the fine-grained granite (141∼144 Ma). Further, the whole-rock and biotite geochemistry, and zircon Hf isotope compositions suggest that the porphyritic granodiorite exhibits a lower degree of magma differentiation, higher oxygen fugacity, higher Cl and lower F contents than the fine-grained granite. The porphyritic granodiorite might provide the most Cu-Pb-Zn budget accompanied by minor Sn for early-stage mineralization. Overall, our study suggests that the Jinkeng Sn-Cu polymetallic deposit formed in two scenarios where the early dominated Cu-Pb-Zn and minor Sn mineralization related to the emplacement of the porphyritic granodiorite is superimposed by the late vein-type Sn-dominated mineralization related to the emplacement of the fine-grained granite. The two isolated mineralizing events (∼147 Ma and ∼141 Ma, respectively) in Jinkeng were probably responded to the regional magmatic activities triggered by the tectonic transformation where two extensional tectonic events were separated by a short contractional event (147–144 Ma). [ABSTRACT FROM AUTHOR]

The Shuikoushan ore field is one of the largest Pb-Zn-Au polymetallic magmatic hydrothermal system in South China and hosts a significant metallogenic potential. The Kangjiawan gold deposit is a low-temperature hydrothermal vein-type gold deposit developed on the periphery of the ore field. Geological chronology suggests that the gold mineralization of the Kangjiawan deposit is coeval with the emplacement of the Shuikoushan granodiorite and related Pb-Zn mineralization. In addition, trace elements characteristics and a narrow δ34S range of -2.94‰ ∼ +3.03 ‰ of pyrite, indicate that ore-forming materials were mainly derived from granitic magmas. Based on the spatial distribution between the ore deposits and granitic intrusions, it is suggested that the Kangjiawan Au deposit is probably as the distal products of magmatic-hydrothermal systems of the deep concealed granitic pluton. The deep parts of the Kangjiawan Au deposit have potential for high-temperature skarn-type mineralization associated with concealed intrusion. Conversely, there is potential for low-temperature Au mineralization linked to the Shuikoushan Granodiorite in the periphery of the Shuikoushan ore field. [Display omitted] • Calcite U-Pb data support that gold mineralization at Kangjiawan occurred at 151.7 ± 5.4 Ma in late Jurassic. • Trace element analysis and S isotope compositions reflect that Kangjiawan gold deposit is genetically linked to granitic magmas. • The Kangjiawan deposit represents distal products of magmatic-hydrothermal systems associated with a deeply concealed granitic pluton. (Meta)sedimentary rock-hosted gold (Au) deposits are globally important Au resources, of which ore genesis and mineral exploration have been attracted considerable attention. However, the precise dating of Au mineralization of those Au deposits remains challenging due to the absence of suitable dating minerals, thus impeding a comprehensive understanding of their genesis. The Kangjiawan Au deposit, situated in the southern Hunan Province, South China, is one of representative (meta)sedimentary rock-hosted Au deposits. Due to the lack of mineralization age, the genesis of Kangjiawan Au deposit is still a matter of debate. Here we report the data of in situ calcite U-Pb dating, in situ trace elements and sulfur isotope analysis of pyrite, to further constrain the mineralization timing and the sources of ore-forming materials of the Kangjiawan Au deposit. Based on the detailed field investigation and petrographic observations, three mineralization stages have been identified: pyrite (Py1) + quartz (Stage I), gold-bearing pyrite (Py2) + polymetallic sulfides + quartz + calcite (Stage II), and gold-bearing pyrite (Py3) + calcite (Stage III). The results of mineralogical and trace elemental analyses indicate that Au are mainly hosted in Py2 (average 14.19 ppm) and Py3 (average 4.80 ppm), primarily as the form of "invisible gold". In situ LA-ICP-MS U-Pb dating on calcite intergrowth with the gold-bearing pyrite (Py3) yields a Tera-Wasserburg lower intercept age of 151.7 ± 5.4 Ma. This age is well consistent with the published zircon U-Pb age (158.3 ± 1.2 Ma) of the nearby Shuikoushan granodiorite, the molybdenite Re-Os age (157.8 ± 1.4 Ma) of the Laoyachao skarn Pb-Zn deposit in the Shuikoushan ore field, and the garnet U-Pb age (159.1 ± 1.9 Ma) of the skarn Pb-Zn ore in depth of the Kangjiawan Au deposit. These suggested that the Au mineralization of the Kangjiawan deposit is coeval with the emplacement of the Shuikoushan granodiorite and Laoyachao Pb-Zn mineralization, which are important parts of the large-scale Middle-Late Jurassic Cu-Au-Pb-Zn Metallogenic event of the Qin-Hang Metallogenic Belt, South China. In addition, trace elemental contents, such as relative low Co, Ni, and Se (i.e., <0.01 to 100 ppm), and a narrow δ34S range of −2.94 ‰ ∼ +3.03 ‰ of pyrite, indicate that ore-forming materials were mainly derived from granitic magmas. Integrated with previous studies, it is suggested that the Au mineralization in the Kangjiawan deposit is genetically associated with the late Jurassic granitic magmatism and is probably as the distal products of the deep-seated concealed granitic intrusions and related proximal skarn Pb-Zn ore. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three types of cobalt minerals and four types of nickel minerals are identified in Dulenggou Cu-Co deposit. • In-situ U-Pb dating of monazite yielded an age of 467 ± 17 Ma for mineralization. • Dulenggou deposit is a SEDEX-type Cu-Co deposit in the East Kunlun orogenic belt. The East Kunlun region in western China stands out as an important polymetallic metallogenic belt hosting economically significant Au, Cu, Fe, Pb, Zn, Sn, Co, Ni and Cr resources. Within this belt lies the Dulenggou deposit, a notable Cu-Co deposit. Three cobalt minerals (cobaltine, siegenite, and glaucodot) and four nickel minerals (ullmannite, gerdorffite, violarite, and millerite) coexisting with chalcopyrite and pyrite were identified in the Dulenggou deposit. The mineralization of Co and Ni primarily occurs in the form of sulfarsenides (cobaltine and gersdorffite) rather than sulfides (siegenite and ullmannite). Sulfides are commonly associated with chalcopyrite, whereas sulfarsenides coexist with chalcopyrite occasionally within the host rocks. The presence of organic-rich surrounding sedimentary rocks reduces oxygen fugacity, and the increase in arsenic content may influence the paragenetic association of minerals. The sequence of mineral formation is Py0 (host rocks) → PyI + Ccp + Co-Ni minerals (the major mineralization stage) → PyII. The mineralization age of the Dulenggou deposit has been determined by in situ U–Pb dating of hydrothermal monazite in closely association with chalcopyrite and Co–Ni minerals, yielding an age of 467 ± 17 Ma. The δ34S values of sulfides (pyrite and chalcopyrite) from ores and host rocks range widely from 1.9 ‰ to 22.1 ‰. From Py0 to PyI to PyII to chalcopyrite, the δ34S values change from 17.6 ‰ to 22.1 ‰, from 9.1 ‰ to 14.6 ‰, from 1.9 ‰ to 7.7 ‰, and from 9.6 ‰ to 13.4 ‰, respectively. The positive δ34S values suggest that the primary sulfur source possibly originated from seawater and/or the host rocks. Based on the geological and geochemical characteristics, the Dulenggou copper-cobalt deposit is identified as a syngenetic sea floor sedimentary exhalative deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • The duration of causative magmatism at Huanggang is ∼ 9 m.y. • Degassing caused the elevation of magma oxygen fugacity. • Fractionation of reduced and S-poor magma controlled the enrichment of Fe and Sn. • Enrichment of metals in the ore-forming fluid could be recorded by apatite. The large-scale Huanggang Skarn Fe-Sn deposit is located in the southern part of the Great Xing'an Range (SGXR), NE China. The causative granitic rocks in the Huanggang ore district are characterized by consistently high SiO 2 contents, low Eu N /Eu N * (0.02–0.24) and Sr/Y (0.2–1.9). The pre-ore granite porphyry and syn -ore syenogranite have been dated through zircon and monazite U-Pb dating at 144.6 ± 1.4 Ma and 138.6 ± 1.3 to 135.9 ± 0.8 Ma, respectively. The U-Pb dating of garnet from ore-associated skarn reveals that the mineralization was happened at 136.5 ± 1.3 Ma, which is consistent with the emplacement age of the ore-related syenogranite. Zircon geochemistry shows that the pre-ore granite porphyry has relatively low oxygen fugacity (average zircon Ce4+/Ce3+ = 14.74), whereas the syn -ore syenogranite is more oxidized (average zircon Ce4+/Ce3+ = 178.9). We suggest that the elevation of oxygen fugacity was most likely caused by degassing. The textural features indicate that apatite crystals from the pre-ore granite porphyry are magmatic in origin. In contrast, textural and chemical characteristics of apatite grains from syn -ore syenogranite reveal that they have been modified by hydrothermal fluids in different degrees. The apatite in both pre- and syn -ore granites display relatively high F and low Cl contents, and very low SO 3 concentrations (i.e., <0.032 wt%), indicate extremely low content of S in the causative magma. Apatite from syn -ore syenogranite display more strong and variable enrichment of LREE relative to HREE compared to those from pre-ore granite porphyry. The extensive present of new REE mineral inclusions (monazite and xenotime) in the altered apatite suggests that the concentrations of Ca and Na must be low in the ore-forming fluid. Apatite from syn -ore syenogranite have higher concentrations of Mo, W, Zn, Sn, and Be than those from pre-ore granite porphyry. Combined with zircon and apatite geochemistry, and whole rock components of the ore-related granites in the Huanggang deposit, we propose that the ore-forming magma has undergone long-term evolution under relatively reduced conditions with extensive fractional crystallization of plagioclase. The reduced and S-poor evolved magma could have promoted the enrichment of Sn and prevented Fe from precipitating as sulfide. This study also reveals that the compositional characteristics of ore-forming fluid, such as the enrichment of ore-forming materials, could be revealed by altered apatite geochemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] • REE mineralization in the Lala deposit primarily formed at ca. 850 Ma. • The host rocks and contemporaneous felsic magmatic rocks serve as the primary sources of REE metallogenic materials. • Na, CO 2 , and F-rich magmatic waters aid REE mineralization, mixing with meteoric waters, leaching the REE from host rocks and early ores. The Lala deposit in the Kangdian metallogenic province is one of the most important iron oxide copper–gold (IOCG) deposits in South China. Rare earth element (REE) activation, migration, and redistribution occurred during late-stage Cu mineralization in the deposit. However, the geological characteristics of REE mineralization and the genetic mechanism of this deposit remain poorly understood. The goal of this study was to investigate REE mineralization and the ore-forming process in the Lala deposit by employing a comprehensive approach that included techniques in petrography, mineralogy, and geochemistry. Mineralogical analysis indicated that the REE-bearing minerals in this deposit include bastnäsite, monazite, parisite, xenotime, apatite, and fluorite. Apatite was observed to have high concentrations of REE (ΣREE ranging from 7,409 to 18,739 ppm). The results of U-Pb isotope dating of bastnäsite and xenotime suggest that the REE mineralization in the Lala deposit primarily formed at ca. 850 Ma, aligning with the Neoproterozoic magmatism in this region. The chondrite-normalized REE pattern of apatite is similar to that of host rocks and contemporaneous magmatic rocks; the ε Nd(t) values of bastnäsite and xenotime (calculated at ca. 850 Ma) ranged from −12.2 to −7.0, which is comparable to the values obtained for contemporaneous country rock (−8.7 to −6.4) and felsic intrusive rocks (−9.6 to 4.4). This similarity indicates that the host rocks and contemporaneous felsic magmatic rocks serve as the primary sources of REE metallogenic materials. The ∼ 850 Ma REE mineralization overprints the early stage Fe-Cu mineralization and is associated with a Neoproterozoic magmatic event. During this process, Na, CO 2 , and F-rich magmatic water mixes with meteoric water and leaches REE from host rocks and early-stage ores. Under the disintegration of REEs, F-complex in hydrothermal fluids, REE minerals (e.g., monazite, bastnäsite, parisite, and xenotime) precipitate together with apatite and fluorite in the Fe-Cu ores. [ABSTRACT FROM AUTHOR]

[Display omitted] • First direct timing constraints on the Jiaoxi and Anglonggangri W mineralization. • Garnet-muscovite granite provided most Fe in Anglonggangri ore-forming metals. • Varied fluid component and redox state in wolframite and scheelite precipitation. • Highly-evolved granites play critical roles on the Fe-rich wolframite formation. Critical factors controlling Fe-enriched wolframite formation in the quartz vein-type wolframite deposit are in controversy. The Jiaoxi and Anglonggangri are typical examples of quartz vein-type wolframite mineralization found in western Lhasa terrane. The Jiaoxi wolframite comprise dominantly early hübnerite with late ferberite, whereas, the Anglonggangri wolframite are mainly ferberite. Wolframite U-Pb dating yields direct timing of 11.0 ± 0.2 Ma and 9.7 ± 0.2 Ma for Jiaoxi and Anglonggangri tungsten mineralization, respectively. Ages together with enrichment of Nb, Ta, Ti, and Sc and depletion of Sr and most Eu anomaly within Anglonggangri wolframite confirm that metals and fluids were mainly derived from the ore-forming garnet-muscovite granite. Iron and Mn mapping of garnet in the garnet-muscovite granite suggests this granite has changed from the early Mn-enriched to late Fe-rich affinity. Therefore, initial ore-forming fluids exsolved from garnet-muscovite granite have Fe-rich composition, that was significantly modified during tungsten mineralization. Positive trend between Mg and Fe/(Fe + Mn) of wolframite indicates biotite breakdown from country rock of biotite-muscovite granite to add Fe and Mg into fluid during greisenization. Meanwhile, decomposition of plagioclase and K-feldspar provided Ca, Sr, and Eu to form late scheelite. Enrichment of Sr with positive Eu anomaly and decline of REE, Nb, and Ta are typical features of the highly evolved and modified fluid. Positive and negative Eu anomalies within the same wolframite grains reveal the oxidized character and fluctuating composition of fluid during wolframite precipitation. By contrast, negative Eu anomaly and low Mo abundance of scheelite indicate the reducing fluid during scheelite crystallization. Identification of metal and fluid sources for Anglonggangri ferberite highlights the evolved granites play more crucial roles on ferberite formation than early hübnerite crystallization and Fe addition from country rocks during hydrothermal interaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Exhalative-syngenetic process and ductile–brittle deformation contributing to Co mineralization. • Two episodes of Co mineralization occurred at ca. 453 Ma and 190 Ma, respectively. • Tectonic-hydrothermal overprinting event raising the tenor of primary ore. Stratiform Cu-Co deposits hosted in (meta-) sedimentary and volcaniclastic rocks contribute two-thirds of the global Co supply. However, the mechanisms driving Co remobilization during tectonic-hydrothermal overprinting events remain poorly understood. As a dominant Co repository, pyrite can provide valuable insights into mineralization history due to its refractory nature. Here, we present the first micro-analytical investigation of pyrite from the Tuolugou Co(–Au) deposit in East Kunlun Orogenic Belt. Ore textures indicate that Co mineralization is attributed to two distinct stages: primary enrichment and subsequent overprinting processes. The former is characterized by pyrite (PyI with up to 3.92 wt% Co) remnants exhibiting oscillatory zones, while the latter is marked by deformation of pyrite (PyII) ores. Three overprinting episodes, namely Da, Db, and Dc, are further distinguished according to varying extents of deformation and mineral assemblages. The Da is characterized by synkinematic PyIIa (up to 4.18 wt% Co) augens, which were most likely formed via pressure–solution mechanism. The Db is represented by polygonal PyIIb (up to 4.75 wt% Co) and siegenite with 120° triple–point junctions. The random orientation and rare intragrain misorientation of cobaltiferous sulfides at Db suggest their formation by recrystallization without plastic strains. The Dc resulted in the formation of Co ± As–rich PyIIc (up to 5.36 wt% Co) along with minor occurrence of cobaltite–gersdorffite, pyrrhotite (up to 1.25 wt% Co), and marcasite (up to 1.28 wt% Co). The PyIIc replacing PyI underscores the role of fluid-coupled dissolution and precipitation during fluid–rock interactions in the formation of these cobaltiferous sulfide assemblages at Dc. The presence of PyIIc infilling within the PyI fissures, in conjunction with the transition from siegenite to cobaltite–gersdorffite, suggests a shift towards low f O2 and low temperature conditions under relatively brittle setting. There is a discernible disparity in sulfur isotope compositions between the two mineralization stages. The PyI exhibits a narrow range of δ34S V–CDT values from –2.14 to 1.35 ‰, indicating a magmatic sulfur origin. In contrast, PyII displays a wide δ34S V–CDT range of –5.22 to 6.16 ‰, suggesting an involvement of strata sulfur during the overprinting stage. Monazite U-Pb dating has effectively constrained two mineralization events. The ca. 453 Ma age implies a potential correlation of the primary Co mineralization with the Late Ordovician to Early Silurian exhalative-syngenetic processes in a Proto–Tethyan-related post–collisional extension setting. Conversely, the ca. 190 Ma age indicates that Co remobilization was instigated by the early Mesozoic ductile–brittle deformation associated with the Paleo-Tethyan orogenesis. Finally, geochemical modeling was performed by simulating the interaction of a Co-rich acidic, reducing fluid with typical quartz-albitite rocks. The simulations demonstrate the appearance of independent Co minerals such as Co-pentlandite during the reaction progression, greatly supporting ore upgrading via tectonic-hydrothermal overprinting. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new type clay-Li deposit is found in southern Hubei Province, China. • This deposit was formed by fault-controlled hydrothermal alteration. • Hydrothermal apatite U-Pb dating indicates an age of 135.2 ± 13.9 Ma. • The Li enrichment is related to the Mufushan granitic magmatism. Clay-Li deposits are among the major Li deposits in the world and occur mainly in sedimentary and/or volcanic-sedimentary strata. The Li orebodies are generally stratiform and stratibound, and Li is mainly hosted in various clay minerals. Here, we report a new type of clay-Li deposit that occurs along fault zones developed in metasedimentary rocks with significant alteration, and Li is also hosted in clay minerals in the Jinyinshan area in Xianning, southern Hubei Province, China. The study area has no granitic rock outcrops, but approximately 15 km south is the Mufushan granite batholith, where large-scale rare metal mineralization, such as Li, Be, Nb and Ta granitic pegmatites, developed in the internal and outer contact zones of the granite batholith. In this study, high-Li clay minerals, including chlorite, kaolinite and smectite, were identified. The enrichment of Li is closely related to hydrothermal activity along the F9 fault in the region. Hydrothermal apatite coexisting with Li-clay in the orebody along the fault zone yielded an in situ U–Pb age of 135.2 ± 13.9 Ma, which is in good agreement with the ages of granites and Li-pegmatites around the Mufushan batholith. Petrographic, geochemical, and chronological evidence suggests that the ore-forming fluids and Li were likely sourced from the Mufushan granite batholith or a similar blind granite at the depth of the study area; that is, the granite-derived ore-forming fluids can travel long distances along fault zones, and during this pathway, Li from the metasedimentary rocks (i.e., the Lengjiaxi Group) may also have been leached by the fluids and contributed to the Li mineralization in the Jinyinshan clay-Li deposit. The close spatial relationships among different clay minerals indicate that fluid physical–chemical conditions (changes in temperature) may play a crucial role in controlling the formation of Li-rich clay minerals. Our study indicates that the Mufushan area has great potential for hydrothermal clay-Li mineralization occurring in the Lengjiaxi Group metasedimentary rocks around the Mufushan batholith. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two hydrothermal mineralization events in this deposit are identified: quartz-sericite-pyrite-native gold (I) stage and chlorite-quartz-sericite-chalcopyrite-electrum (stage II). • This study provides additional age constraints on the host rocks (Caledonian granitic rocks) in the Hebaoshan area, with ages ranging from 441 to 446 Ma, as well as two mineralization events at approximately 238.46 ± 2.01 Ma and 179.54 ± 7.28 Ma. • The combination of ages and geological evidence suggests that the first mineralization event is associated with the intracontinental orogeny of the Yangtze Block and Cathaysia Block, as well as the flat subduction of the Paleo-Pacific Plate. The second mineralization event is related to the extensional tectonic activity following the collision between the Yangtze Block and Huaxia Block. The Hebaoshan gold deposit (41.5 t Au @ 3.5 g/t) is located in the southeastern region of the South China Block, central part of the Wuyishan metallogenic belt. The ore-hosting rocks in this area are predominantly Precambrian metasedimentary rocks and Caledonian granitic rocks. Two hydrothermal mineralization stages can be distinguished: a quartz-sericite-pyrite-native gold (stage I) and a chlorite-quartz-sericite-chalcopyrite-electrum (stage II), with hydrothermal monazite and rutile are firstly identified in separate stages. The complex geological history of the region has resulted in ongoing debates regarding the age of gold mineralization and the genesis of the major gold deposits in this area. In order to precisely constrain the mineralization age of the deposit and further establish a genetic model for the ore deposit, LA-ICP-MS U-Pb dating and trace element analysis on accessory minerals were conducted. Based on the textures mineral assemblages, and geochemical features of the accessory minerals, magmatic apatite, hydrothermal rutile, and both magmatic and hydrothermal monazite were identified. The U-Pb ages of magmatic apatite and monazite are determined to be 445.3 ± 15.80, 441.3 ± 15.10 Ma and 446.57 ± 1.03 Ma, respectively, suggesting that these ages represent the emplacement ages of the Caledonian intrusive rocks. The ages of hydrothermal monazite and hydrothermal rutile are determined to be 238.46 ± 2.01 Ma (single-mineral analysis), 238.46 ± 2.01 Ma (in-suit analysis) and 179.54 ± 7.28 Ma, respectively, suggesting that represent two mineralization events during the Late Triassic to early Jurassic in the Hebaoshan area. These data provide new constraints on the mineralization process in the Hebaoshan deposit and excludes the link between gold mineralization and the intrusion of the Caledonian granites. Regionally, It is speculated that the two mineralization events at Hebaoshan are respectively associated with intracontinental orogenic movements between the Yangtze Block and Cathaysia Block, the flat-slab subduction of the Paleo-Pacific Plate (stage I), and the subsequent extensional tectonics related to the collision between the Yangtze Block and Cathaysia Block (stage II). Our study indicates that the timing of multiple episodic mineralization can be constrained by analysis of accessory minerals, which provides a geological basis for better genetic model for the deposit and provide geological evidence for unraveling the relationships between magmatic activities and mineralization events in the region. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magmatic/hydrothermal cassiterites are identified in the Yuanlinzi Sn-Cu deposit. • Tin mineralization in the Yuanlinzi Sn-Cu deposit occurred at ca. 139 Ma. • An ore-forming environment with increasing oxygen fugacity is proposed. • Sc/V ratio of cassiterite may monitor redox state of its related melt/fluid. Microtextural, U–Pb isotopic, and trace element analyses were conducted on magmatic and hydrothermal cassiterites from the Yuanlinzi Sn–Cu deposit (NE China) to determine the timing of mineralization and investigate the ore-forming process. Magmatic cassiterites are disseminated in pegmatite, while hydrothermal cassiterites can be classified into three types: cassiterite-bearing stockworks in pegmatite, disseminated cassiterite in wall rock, and cassiterite-quartz-feldspar veins. U–Pb dating of the four types of cassiterite yields a similar age of ∼ 139 Ma, which is consistent with the ages of regional tin mineralization and granites within the mining district. These results suggest a strong association between Early Cretaceous magmatism and tin mineralization. The four types of cassiterite exhibit comparable textural features, characterized by alternating oscillatory CL zonation and dark homogeneous bands, with the latter commonly enriched in W, Nb, Ta, and U. The direct substitution of tetravalent ions, including Zr, Hf, Ti, and V, with Sn4+ and the coupled substitutions of Fe3+ + OH– = Sn4+ + O2– or Fe3+ + H+ = Sn4+, 2Sb3+ + U6+ = 3Sn4+ and Sc3+ + V5+ = 2Sn4+ are responsible for the incorporation of these elements in cassiterite. The enrichment of W, Nb, Ta, and U in the dark domains of cassiterite is related to the coupled substitution of W + U and Nb + Ta, while the excess of Nb and Ta in the oscillatory-zoned domains may be attributed to the substitution of 4(Nb, Ta)5+ + □ = 5Sn4+. The trace element variations observed in the four types of cassiterite, particularly Al, Sc, Ti, V, and Fe, reflect the ongoing enhancement of the water–rock reaction during the mineralization process. The examination of redox-sensitive elements such as Fe, U, and V suggested that tin mineralization in the Yuanlinzi deposit occurred in an oxidizing environment where oxygen fugacity gradually increased. Additionally, we proposed that the Sc/V ratio of cassiterite could serve as an indicator of the redox state of the associated melt/fluid. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal apatite U–Pb age (208.1 ± 6.5 Ma) is coeval with peripheral intrusions. • C–O–S–Pb isotopes indicate a magmatic source for the ore fluid and material. • The Qukuleke is classified as a sediment-hosted intrusion-related deposit. • Intrusion-related Au ore system is a valuable target for regional exploration. Genetic classification of sediment-hosted Au deposits is often disputed in many orogenic belts around the world. The marine sediment-hosted Qukuleke Au deposit (>5 t Au) is an example of this, which has been attributed to orogenic or intrusion-related type. This paper addresses its metallogeny through detailed geologic and petrographic studies, together with apatite U–Pb dating and C–O–S–Pb isotopes. The hydrothermal paragenesis at Qukuleke is divided into three stages (I to III): Stage I (pre-ore) sheeted quartz veins; Stage II (main ore) pervasive sericite ± carbonate ± apatite ± pyrite ± arsenopyrite alteration associated with quartz–calcite ± stibnite veins; Stage III (post-ore) barren calcite veins. LA-ICP–MS hydrothermal apatite U–Pb dating on Stage II disseminated Au ore yielded 208.1 ± 6.5 Ma, coeval with the Late Triassic post-collisional intrusions from the periphery of Qukuleke deposit. Carbon–oxygen isotopes of Au–Sb ore-related hydrothermal calcite show that the hydrothermal fluids were derived from the marine carbonate ore host with considerable magmatic input. Lead–sulfur isotopes of the Au–Sb ore-related are consistent with those of coeval intrusions around the deposit, but different from those of the local sedimentary strata. Our age and geochemical data suggest the presence of a magma source that supplied the hydrothermal fluids, sulfur and metals for the mineralization. Combining the low sulfide content and the Au–As–W–Sb–Mo assemblage characteristics, the Qukuleke is best classified as a sediment-hosted intrusion-related Au deposit. Considering also the discovery of the large coeval Qukukekedong Au deposit nearby, we propose that Late Triassic intrusion-related Au system is a high-potential exploration target in the western EKOB. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu–Pb–Zn skarn related granodiorite and diorite formed at 245–243 Ma. • Phlogopite Ar–Ar dating constrains that skarn mineralization occurs at 240 ± 1 Ma. • Middle Triassic ore-related granodiorite and diorite formed by magma mixing. • Mantle-derived magma plays a vital role in the formation of skarn mineralization. The skarn is one of the most significant Cu–Pb–Zn mineralization worldwide. The timing of the magmatic-hydrothermal activity is of importance for understanding the Cu–Pb–Zn mineralization process. The Cu–Pb–Zn skarn mineralization has been recognized in the northwestern section of the Wulonggou gold ore field, Eastern Kunlun Orogen (EKLO), NW China. However, no precise geochronological data has been measured for the Cu–Pb–Zn mineralization, and the source of ore-forming materials is also not well studied. In this study, we present new LA-ICPMS U–Pb ages and Sr–Nd–Hf isotopic compositions for granodiorite and diorite in the northern section of the Wulonggou gold ore field, as well as an Ar–Ar age for phlogopite and Pb isotopic compositions for sulfides and intrusions, further to constrain the ages of mineralization and magmatism, and the source of ore-forming materials. Two granodiorite samples yield mean ages of 245 ± 2 to 243 ± 2 Ma and a diorite has a mean age of 245 ± 2 Ma. A phlogopite sample, which is associated with Cu–Pb–Zn mineralization, has been chosen to precisely date the formation of Cu–Pb–Zn ores by Ar–Ar method and yields a well–defined plateau age of 240.4 ± 1.2 Ma. These results indicate that the Cu–Pb–Zn skarn mineralization formed in the Middle Triassic and is closely related to the coeval magmatism. The ε Hf (t) values of the ore-related granodioritic and dioritic rocks range from −2.8 to +2.5, whereas an un-mineralized granodiorite sample (WHFG–1) shows lower ε Hf (t) values of –9.3 to –3.4, indicating that these magmatic rocks are derived from the mixing of magma with different proportions of mantle- and crust-components. A mixing model with ∼40–70 % mantle contribution involved in the formation of ore-related granodiorite and diorite was revealed by Sr–Nd–Hf isotopic compositions. Combined with Pb isotopic compositions for sulfides, feldspar, and bulk rocks, we consider a common source for the ore-forming materials and magmatism. In addition, higher ε Hf (t) and ε Nd (t) values for ore-related magmatism implicate that mantle-derived melts show a vital role in the Cu–Pb–Zn skarn mineralization process. [ABSTRACT FROM AUTHOR]

Representative CL images showing the texture of the Yangla scheelite and corresponding variations in the REE patterns throughout the evolution of the oreforming fluids. [Display omitted] • Three types of scheelite are identified based on their microstructure. • Tungsten mineralization age is significantly later than the Triassic Cu mineralization in the Yangla district. • Source and evolution ore-forming fluids were constrained by scheelite texture and geochemistry. The Yangla Cu-polymetallic deposit is the largest skarn Cu deposit in the Jinshajiang suture zone. Recently, an new W orebody was identified in the depths of the Cu orebodies. However, the genetic relationship between W and Cu orebodies, along with the tungsten ore-forming processes, remains unclear. This study delves into the careful investigation of three types of scheelites focusing on microstructure, trace element compositions and Sr isotope geochemistry. The aim is to elucidate the source and evolution of ore-forming fluids and ore genesis in the multi-episodic metallogenic systems. Primary scheelite (Sch-I) generally displays oscillatory zoning in CL images with the lowest REE (3.8–142 ppm) and highest Sr (604–1480 ppm) contents. Secondary scheelite (Sch-III), commonly precipitated as overprinting rims on primary crystal, has the highest REE (145–1071 ppm) and lowest Sr (376–793 ppm) contents. In contrast, Sch-II represents a transitional stage from primary to secondary, with REE and Sr contents at intermediate levels. Sch-I is characterized by LREE enrichment and a positive Eu anomaly in the chondrite-normalized REE patterns, whereas Sch-III shows MREE-rich patterns with a weak positive Eu anomaly. Scheelite U-Pb dating (30.3 ± 1.5 Ma) indicates that the W mineralization is not genetically related to Triassic granitoids in the Yangla district. Instead, it is likely associated with magmatic activities and tectono-thermal events in the Jinshajiang fault zone during the Cenozoic. The high initial 87Sr/86Sr ratios (0.71771–0.72229) in the scheelite, significantly higher than those of Triassic granites and ore-hosting marble, suggest that the geochemical features of Sch-I are inherited from the parental ore-forming fluids. These fluids are likely derived from the mixed hydrothermal fluids involved by the Neoproterozoic strata and/or concealed magmatism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hongqiling Sn-W polymetallic deposit is a product of granitic magmatism in Late Jurassic. • The elemental composition of primary cassiterite is controlled by the compositions of ore-forming fluid and the rate of crystallization. Hongqiling deposit is one of the most typical hydrothermal vein type Sn-W polymetallic deposits in the Dongpo ore field, southern Hunan. It is an ideal object to study the Sn-W mineralization in the Nanling metallogenic belt and even in the whole South China Block, and to reveal the regional metallogenetic regularity. Based on the detailed investigation of the deposit geology, this paper discusses the mineralization age and processes of the Hongqiling hydrothermal vein type Sn-W polymetallic deposit by LA-MC-ICP-MS in-situ U-Pb dating and trace element geochemistry of cassiterite from the quartz vein type Sn-W ore body. Cathodoluminescence (CL) imaging shows that cassiterite in Hongqiling deposit can be divided into two generations. primary cassiterite (Cst-I) and altered cassiterite (Cst-II). The LA-MC-ICP-MS in-situ U-Pb age of the two groups of Cst-I samples are 158.9 ± 0.7 Ma and 158.4 ± 0.8 Ma, respectively, which are well consistent with the mineralization ages of most Sn-W deposits in the Nanling metallogenic belt, and are also consistent with the ages of middle to late Jurassic magmatic activity represented by the Qianlishan intrusion. This indicates that the Hongqiling deposit, like many Sn-W deposits in the Nanling metallogenic belt, is genetically related to the regional Middle to Late Jurassic granitic magmatic activities. LA-ICP-MS trace element analysis shows that trace elements such as Na and Cs are mainly distributed in fluid inclusions in cassiterite, while the major elements such as Mg, Al, and Si are mainly distributed in the mineral inclusions, and other elements such as W, U, Zr, Hf and Ti are mainly distributed in the cassiterite by isomorphic substitution. The high Fe and W contents in both primary and altered cassiterite indicate that the ore-forming fluid of Hongqiling deposit is mainly derived from granitic magma. The fluctuating variation of Fe, V, Sc, Ti, Zr, Hf, Nb and Ta in the primary cassiterite with the crystalline bands indicates that there are two large-scale pulses of magmatic hydrothermal fluid during the mineralization process, while the altered cassiterite is relatively depleted of Ti, Sc, Zr and U elements, and enriched in Pb which may represent the compositional characteristics of the late-stage fluid. In summary, the Hongqiling hydrothermal vein type Sn-W polymetallic deposit was formed by the pulsating exsolution of magmatic hydrothermal fluid of late Jurassic granitic magmatism. The trace elemental compositions of primary cassiterite are generally controlled by the compositions of ore-forming fluid and the rate of crystallization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The host granite belongs to the ca. 1860 Ma Donington Suite. • The host granite experienced a thermal event (>350 °C) at ca. 1770 Ma. • Porphyritic volcanic units and polylithic breccias formed at ca. 1590 Ma. • Iron Oxide Copper-Gold mineralisation formed at ca. 1585 Ma. • Uranium mineralisation, post-ore veining and late alteration formed at ca. 600–500 Ma. The Carrapateena Iron Oxide Copper-Gold (IOCG) deposit is located on the eastern margin of the Gawler Craton, approximately ∼475 km NE of Adelaide, South Australia. The deposit is hosted within a granite belonging to the Donington Suite and contains various polylithic breccias and intrusive volcanic units. Multiple stages of alteration/mineralisation are present throughout the deposit, which includes: (1) pre-mineralisation alteration; (2) hematite I; (3) Cu-Au mineralisation; (4) hematite II & REE mineralisation; (5) uranium mineralisation; (6) post-mineralisation alteration/veining. In order to establish a temporal framework, multi-mineral U–Pb geochronology was conducted on a variety of lithologies throughout the deposit and across multiple stages of alteration/mineralisation. Zircons from the host granite are predominantly discordant, with two concordant analyses from two samples producing 207Pb/206Pb ages of ca. 1880–1861 Ma, consistent with the emplacement of the Donington Suite (1860–1850 Ma). Apatite U–Pb geochronology performed on the granite-bearing samples produced ages of ca. 1775–1767 Ma, indicating the presence of a moderate temperature (≥350 °C) thermal event approximately 100 Ma after the crystallisation of the host rock. Zircon U–Pb geochronology conducted on a porphyritic volcanic unit and two polylithic breccia samples produce bi-modal age populations at ca. 1880–1860 Ma & ca. 1590 Ma. The ca. 1880–1860 Ma age reflects zircons inherited from the host granite, while the younger ca. 1590 Ma population represents the crystallisation age of the porphyritic volcanic unit and the maximum formation age of the polylithic breccias. U–Pb geochronology conducted on apatite, hematite and xenotime associated with various stages of mineralisation produce ages of ca. 1585 Ma, consistent with a major Fe-Cu-Au metallogenic event throughout the Gawler Craton. U–Pb geochronology performed on uraninite, apatite located within a late vein, and "vuggy" hematite records a second hydrothermal event from ca. 600–500 Ma, reflecting a period of minor deformation and deposit-wide fluid circulation. [ABSTRACT FROM AUTHOR]

Schematic diagram of textural characteristics, formation process and hydrothermal spatial evolution of garnets at different locations in the Huanggangliang Fe-Sn deposit. [Display omitted] • U-Pb dating of garnet constrains the onset of hydrothermal activity and the formation of skarn. • The hydrothermal physicochemical conditions of the Huanggangliang garnets are constrained. • Garnet trace elements are important in distinguishing different mineralization conditions. • Tin-rich garnet can be used as an indicator mineral for exploration of skarn-type tin deposits. Cu-Fe (Au), W-Sn (Mo), Pb-Zn (Ag) and other element assemblages are common in many skarn deposits, but examples of Fe and Sn coexistence in nature are relatively rare. The Huanggangliang deposit in the southern Great Xing'an Range is the largest Fe-Sn polymetallic deposit in northern China, and there are five main mining areas (SK Ⅰ–SK Ⅴ) distributed along a SW–NE trend. SK Ⅰ and SK Ⅲ are the two larger mining areas in the Huanggangliang deposit, and their mineral assemblages and wall-rocks are significantly different: cassiterite and metal sulfides are duncommon in SK Ⅰ (andesite), while they are widely distributed in SK Ⅲ (marble). Garnet is widely distributed in SK Ⅰ and SK Ⅲ mining areas, and provides a good opportunity to explore the mechanism of Fe-Sn assemblage differentiation. Three types of garnet are distinguishable (Grt 1, Grt 2 and Grt 3) based on their mineral associations, textures and locations, and they mainly belong to the andradite-grossular solid solution series. The LA–ICP–MS U-Pb ages of the garnets from SK Ⅰ and SK Ⅲ are 136.0 ± 1.2 Ma (n = 25, MSWD = 1.9) and 136.2 ± 2.6 Ma (n = 37, MSWD = 1.8), respectively, suggesting that magmatic-hydrothermal activity in these two mining areas began at the same time. Grt 1 (located deep in SK Ⅰ and SK Ⅲ) and Grt 2 (located shallowly in SK Ⅰ) are mainly andradite, while Grt 3 (located shallowly in SK Ⅲ) is mainly grossular. They are all enriched in high field strength elements (HFSEs) and depleted in large ion lithophile elements (LILEs), and their REE patterns are enriched in light rare earth elements (LREEs) and depleted in heavy rare earth elements (HREEs). However, Grt Ⅰ-1a and 1b (deep garnets in SK Ⅰ) exhibit obvious positive Eu anomalies, while the other garnet types exhibit negative or no obvious Eu anomalies. Additionally, Grt 3 has high contents of V, Sn, U, Th, Zn and Y, and low contents of W and Mo. This pattern implies that the garnets in deep SK Ⅰ may have formed under oxidizing conditions with high temperatures, high oxygen fugacity (f O 2) and weak acidity, while the garnets in shallow SK Ⅲ formed under reducing conditions with moderate temperatures, moderate f O 2 and near-neutral pH. The garnets in shallow SK Ⅰ and deep SK Ⅲ may have formed under weak oxidation–reduction conditions at moderate to high temperatures, moderate f O 2 and weakly acidic to neutral pH conditions. Our newly reported field geological, mineralogical, and geochemical data from garnet suggest that the ore-forming fluids of the Huanggangliang were magmatic-hydrothermal fluids mixed with slightly acidic external fluids, chloride complexes may have been the main transport ligands of REEs. The metallogenic environment may be an important factor leading to the difference of mineral assemblages in the Huanggangliang deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • The magmatic-hydrothermal system of Yangla skarn Cu deposit is relatively reduced. • The barren quartz porphyry was also originated from reduced magmas and thus less fertile for porphyry Cu formation. • Intense fluid-carbonate rocks interaction and fluid focusing could be the key to formation of the reduced Yangla Cu deposit. In the Paleo-Tethyan orogenic belt, reduced mineralization systems result in extensive saturation and segregation of magmatic sulfide phases, which in turn leads to the loss of chalcophile elements and hinders the precipitation of large amounts of copper. As a result, porphyry Cu deposits are rare within the belt. In this contribution, we investigate the composition of zircons from the granodiorite, fluid inclusions and hydrothermal scheelite from orebodies of the Yangla Skarn Cu deposit, and assess the magmatic-hydrothermal redox state of the system. The igneous zircons from ore-causative granodiorite have negative Eu anomalies (Eu N /Eu N * = 0.27 ± 0.03, n = 11) and the calculated ΔFMQ values are -0.23 ± 0.31 (n = 11). The ore-forming fluids in the pre-ore stage was rich in CH 4 , and precipitating hydrothermal scheelite in the syn -ore stage with low Mo contents (Mo = 17.4 to 149 ppm, mean 57.7 ppm) and positive Ce anomalies (Ce N /Ce N * = 1.14 ± 0.06, n = 29). The geochemistry suggests that the magmatic-hydrothermal system at Yangla is relatively reduced, consistent with the abundant development of pyrrhotite in the ore body. In addition, we have carried out zircon SIMS U-Pb dating and trace analysis of the barren quartz porphyry in the Yangla ore field, which gives an emplacement age of 227 Ma and is also derived from reduced magmas (ΔFMQ = -1.27 ± 0.55; Eu N /Eu N * = 0.32 ± 0.10, n = 7) that were less fertile for porphyry Cu formation. By comparing with the barren quartz porphyry, we suggest that the key control of the skarn ore body may have been that the low-permeability of carbonate units seal the mineralizing fluids, enhancing fluid-carbonate reactions and concentrating the sulfides in a relatively small area. Without these processes, it can only form barren porphyry system. We highlight that, unlike typical porphyry Cu deposits, intense fluid-carbonate rocks interaction and fluid focusing could result in skarn Cu formation, even though in relatively reduced magmatic-hydrothermal conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pegmatites in South Washixia and Tamuqie were emplaced in shear zones. • Li mineralization of the South Washixia and Tamuqie Li granitic pegmatite deposits formed at 448 ∼ 445 Ma. • The large Li deposits formed at final collision of three micro-continents. Micro-continent collision and amalgamation play pivotal roles in continental convergence and contribute significantly to continental crustal growth. However, the understanding of multiple micro-continent amalgamation processes, particularly their influence on the formation of large Li-Be deposits, remains limited. The Altun orogenic system, resulting from the collision and amalgamation of three micro-continents in the Proto-Tethys Ocean, has recently revealed numerous granitic pegmatite-type Li-Be deposits, presenting an ideal opportunity to investigate the mineralization. Our research focused on two large granitic pegmatite Li deposits, South Washixia and Tamuqie in the Central Altun Tagh, Northwest China. Our findings suggest: 1) The structural and photomicrograph characteristics observed in both the Tamuqie and South Washixia granitic pegmatite Li deposits, indicate that the pegmatites emplaced in shear zone within a contractional deformation zone. 2) The age of the large granitic pegmatite Li deposit in South Washixia between 447 ∼ 445 Ma, while the Tamuqie Li pegmatites formed at 448 Ma with Li-barren pegmatites formed at around 418 Ma. It is suggested that the large granitic pegmatite Li deposit in the Central Altun Block, encompassing South Washixia and Tamuqie granitic pegmatite Li deposits, originated during the final collision event of three micro-continent blocks (Qaidam, Altun-Qilian, and Dunhuang-Alex). We suggest that during the final collision and amalgamation event of multiple micro-continents triggering intense compression and thickening of the crust, and the thickened lower crust may undergo shear-driven dehydration melting of biotite in granulite facies to produce large-volume granitic magmas. These magmas crystallize and differentiate into lithium-rich pegmatitic magmas along shear zones, forming large lithium pegmatite deposits. Our research presents a novel mechanism for the formation of granitic pegmatite Li deposits, which emphasizes the role of shear-driven dehydration melting during the final collision and amalgamation events of three micro-continents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Diverse W metallogeny of the Baiyunxian ore field intensively occurred in 156–153 Ma. • W metallogeny was associated with Late Jurassic highly evolved magmatic phases. • Metal element are derived from remelting of metasedimentary crustal basement. • Lithology of wall rocks is the major cause of varied W mineralization types. The Baiyunxian ore field, a large tungsten ore filed in the Nanling Metallogenic Belt of South China, hosts a variety of tungsten deposits such as the Dapu (quartz wolframite vein type), Chashanjiao (skarn type), Toutianmen (greisen type), and Dashan (quartz scheelite vein type). However, precise mineralization ages of these deposits remain poorly constrained and this has long vexed a better understanding of genetic relationships between diverse W mineralization types and the spatially associated Jiufeng granitic complexes. Here, we report firsthand zircon U–Pb, monazite U–Pb, garnet U–Pb, cassiterite U–Pb, and molybdenite Re–Os ages of different granites and ores from the Baiyunxian ore field. The Jiufeng granitic complexes consists of phase Ⅰ biotite granite (P1), phase Ⅱ two-mica granite (P2), and phase Ⅲ granitic dikes (P3, including greisen W ore). Zircons from P1 granite define a concordant U–Pb age of 166.0 ± 0.9 Ma (MSWD = 1.1). Monazites from P2 granite yielded a Tera–Wasserburg lower intercept age of 159.2 ± 0.7 Ma (MSWD = 0.45). In addition, zircons and monazites from P3 granite in the Toutianmen deposit yield a concordant U–Pb age of 154.7 ± 1.3 Ma (MSWD = 1.3) and a Tera–Wasserburg lower intercept age of 156.6 ± 1.9 Ma (MSWD = 0.14), respectively, suggestive of multi-stage emplacement processes of the Jiufeng complexes. Ten molybdenite samples from the Dapu deposit generate an isochron age of 156.0 ± 3.0 Ma (MSWD = 0.93). In situ garnet and cassiterite LA-ICP-MS U–Pb dating results of the Chashanjiao skarn deposit yield lower Tera–Wasserburg intercept ages of 155.3 ± 1.2 Ma (MSWD = 1.6) and 153.4 ± 3.7 Ma (MSWD = 1.3), respectively. These dating results indicate that different W mineralization events in the Baiyunxian ore field intensively occurred in the Late Jurassic (∼159–153 Ma). Despite a close spatial relationship between various W orebodies and P1 granite, the geochronological results demonstrate that extensive W metallogeny in the Baiyunxian ore filed likely occurred later than P1 granite and contemporaneous with P2–3 granites. In addition, scheelites from the four deposits have similar REE patterns that are characterized by weak MREE enrichment, despite few exceptions being found in scheelites from the Dashan and Chashanjiao deposits. This suggests that the diverse W metallogeny in the Baiyunxian ore field were derived from the same magmatic hydrothermal system and changed as the ore-forming fluid evolved. Multidisciplinary evidence indicates that the Late Jurassic highly evolved P2–3 granites of the Jiufeng complexes were crucial to W mineralization in the Baiyunxian ore field and the lithology of wall rocks exerted first-order control of W mineralization types. [ABSTRACT FROM AUTHOR]

The subduction of the Pacific Plate led to asthenospheric upwelling and thus partial melting of the metasomatized mantle occurred. The REE-bearing initial alkaline magmas were evolved to generate the subsequent exsolution of carbonate melts and REE-rich hydrothermal fluids which existed at relatively shallow depth. Notably, two kinds of REE mineralization occur in the Weishan REE deposit: 1) quartz–barite–carbonate vein type and 2) disseminated and veinlet type. [Display omitted] • Zircon U-Pb dating indicates that the alkaline rocks intruded at ∼ 120 Ma; • Molybdenite Re-Os dating corroborates the mineralization age of ∼ 120 Ma; • Ore-forming magmas were mainly derived from an enriched lithospheric mantle; • Asthenospheric upwelling during craton destruction led to the mantle partial melting. The Weishan REE deposit is one of the largest LREE deposits in China, which is hosted by the Weishan alkaline complex (WSAC) and late Archean gneisses. Two types of mineralization including vein-type and disseminated-type occur in this deposit, of which the former is characterized by large quartz-sulfate-calcite-REE mineral veins cutting all kinds of wallrocks, while the latter is featured by REE minerals disseminated in the alkaline rocks. The vein-type mineralization commonly occurs at shallow depths and has been numerously studied. The disseminated-type mineralization typically occurs at deeper depths, which was newly discovered by drilling exploration and has been poorly studied. In this contribution, zircon U-Pb dating and Hf isotopic analysis as well as whole-rock geochemistry and Sr-Nd isotopic analyses were conducted on the deeply drilled alkaline rocks, combined with molybdenite Re–Os dating on the disseminated ore, with the aim to unravel the petrogenesis of the alkaline rocks and their contributions to the REE mineralization. Zircon U–Pb dating suggests an intrusive age of 119.9 ± 0.9 Ma for the WSAC, which is quite consistent the Re–Os age of 120.0 ± 1.8 Ma for the disseminated ore, corroborating their close genetic correlation. The studied alkaline rocks show enrichment of LILEs, depletion of HFSEs and strong fractionation between LREEs and HREEs, indicating a crustal involvement in the magmas or a metasomatized mantle source. They are characterized by higher Hf (εHf(t) = -6.7 to −12.2) and Nd (εNd(t) = -8.8 to −9.7) isotopic compositions compared with those of the contemporaneous subcontinental lithospheric mantle (SCLM). Based on the above features, it is inferred that the parental magmas of the WSAC were mainly derived from an enriched SCLM with some involvement of asthenospheric mantle-derived materials. The mantle source was likely metasomatized by the subducted Paleo-Pacific oceanic plate, leading to the enrichment of REE and carbonate. Rollback of the oceanic slab during the early Cretaceous resulted in an extensional setting in the study region, which was favorable for partial melting of the metasomatized mantle and thus generated the REE-rich alkaline magmas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Garnet U-Pb dating constrains the age of the Lazhushan deposit at ca. 150 Ma. • Fe skarn mineralization in the Edong district started earlier than previously thought. • The Th/U ratio of garnet is a potential redox indicator of ore fluids. Garnet is ubiquitous in skarn deposits. It is a sensitive recorder of physiochemical conditions and also a powerful geochronometer. In this study, we use garnet trace element geochemistry and U-Pb geochronology as well as sulfur isotopes of sulfides to constrain the age and mineralization process of the Lazhushan Fe skarn deposit. Garnets in the Lazhushan Fe skarn belong to the andradite-grossular solution series and yield a compositional range from Adr 47.2 Gro 50.7 to Adr 97.4 Gro 0.9. There are strong correlations between La N /Yb N ratios and andradite contents in garnet, indicating that garnet major element composition exerts a strong control on the REE fractionation. The decrease of HFSEs (Nb, Ta, Zr, Hf, and Ti) and Co, V, and Mn concentrations from prograde to retrograde garnets may reflect increasing water/rock ratio and decreasing temperature during skarn evolution, respectively. Co-precipitation with magnetite may be responsible for the low concentration of V in the retrograde garnets. The Th/U ratio increase from endoskarn garnet to exoskarn counterparts, probably reflecting an increase of fluid f O 2 due to interactions with evaporate sulfate from the wall rocks. The sulfides in this deposit are enriched in δ34S (up to 13 ‰), conforming the involvement of evaporate sulfate during Fe skarn mineralization. The incursion of evaporate sulfate may have played an important role in magnetite mineralization for the Lazhushan deposit by increasing fluid f O 2 and facilitating the oxidation of Fe2+ to precipitate magnetite. LA-ICP-MS U-Pb dating of garnets from 4 garnet-bearing samples yielded ages of 150.8 ± 6.8 Ma (2σ), 150.9 ± 5.3 Ma (2σ), 150.2 ± 7.9 Ma (2σ), and 150 ± 11 Ma (2σ), which are consistent with zircon weighted mean U–Pb ages of 150.1 ± 2.0 Ma (2σ) and 150.5 ± 1.0 Ma (2σ) of the ore-related intrusion. Combined with previously published metallogenetic ages of skarn deposits in the Edong district, we suggest that the Lazhushan deposit may represent the initiation of Fe skarn mineralization for the Edong district during the Late Mesozoic. [ABSTRACT FROM AUTHOR]

[Display omitted] • Latest Oligocene–Miocene arc magmatism in central Oaxaca developed in a thick continental crust. • Early–mid-Miocene metallogenic epoch in southern Mexico comprises Au-Ag rich epithermal deposits. • Precious metal-rich intermediate-sulfidation epithermal deposits occur at Natividad. • Detailed vein stratigraphy reveals multi-episodic fluid pulses and interaction with wall rocks. • First formal report of argyrodite (Ag 8 GeS 6) in Mexico. The final magmatic arc—Miocene in age—of the long-lived Sierra Madre del Sur igneous province in southern Mexico hosts several epithermal deposits that have hitherto received little attention. The Natividad Au-Ag(-Ge) epithermal deposit is one of them and holds a mining record of > 200 years. Here, we present the first petrogenetic and metallogenic study on the Natividad deposit, in which we use a multi-methodological approach to assess the genesis and evolution of the deposit and its associated igneous rocks. Natividad is mostly hosted by Oligocene–Miocene arc-related dacites (U-Pb zircon dates of 22.8–24.7 Ma), whose geochemical features suggest lower-crustal differentiation (i.e., involvement of garnet) at the base of a thickened continental crust. The mineralization occurs in three multi-stage quartz + carbonate veins and consists of Fe-poor sphalerite (<5 mol. % FeS), galena, chalcopyrite, acanthite, and marcasite (sulfide-dominated stage) overprinted by pearceite-polybasite, pyrargyrite-proustite, tetrahedrite-group minerals, electrum, and argyrodite (Ag 8 GeS 6 ; Ag-sulfosalt-dominated stage). Geothermometry and fluid inclusion data for ore-bearing assemblages reveal fluid temperatures of 170°–400 °C and salinities of 14.6–19.5 wt% NaCl equiv. δ18O from 0.8 ‰ to 7.5 ‰ in mineralizing fluids suggests mixtures of magmatic brines and meteoric waters, while δ13C from –8.4 ‰ to 2.2 ‰ indicates the recycling of organic carbon from the meta -sedimentary basement. Further, δ34S from –3.2 ‰ to –0.3 ‰ in sulfides attest to magmatic S. These results align with an intermediate-sulfidation epithermal model, whereby upwelling magmatic ore-bearing brines precipitated the ores due to conductive cooling, dilution, and, locally, boiling. Our study highlights the metallogenic potential of Miocene magmatism in the eastern Sierra Madre de Sur. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Yuku ore field shows prolonged post-mineralization cooling varying from 158 to 35 Ma. • The Yuku ore field underwent rapid cooling at ca. 132–125 Ma and multiple various degrees of cooling after 125 Ma. • The un-exhumated areas around the Yuku pluton are favorable sites for Mo prospecting. Molybdenum (Mo) is an important globally strategic metal and mostly occurs as molybdenite (MoS 2) in diverse Mo deposits. The Yuku ore field includes multiple porphyry-skarn Mo deposits and forms a significant world-class Mo cluster in the Qinling molybdenum belt, central China. Previous studies on the ore field were largely related to its genesis, and did not highlight the post-mineralization modifications that are important to formulate prospecting strategies. The exhumation and preservation processes of the ore field through multiple tectonic events also remain poorly understood. Here, we conducted multi-method apatite U-Pb, fission-track and (U-Th)/He and zircon (U-Th)/He medium- to low-temperature thermochronology and related thermal history modelling on granitoids from the ore-hosting Shibaogou and Yuku plutons in the Yuku ore field, and integrated published studies to unravel the post-mineralization exhumation and preservation of Mo deposits. The newly determined apatite U-Pb (158.3–104.9 Ma), zircon (U-Th)/He (158.2–115.0 Ma), apatite fission-track (90.8–63.1 Ma), and apatite (U-Th)/He (67.8–35.3 Ma) ages in this study document multiple cooling pulses during post-magma emplacement. The low-temperature thermochronological ages of 158.2–35.3 Ma also record the post-mineralization cooling and exhumation history. The thermal history modelling indicates an Early Cretaceous (132–125 Ma) rapid cooling pulse, two enhanced (or accelerated) cooling pulses at ca. 125–59 Ma and post-10 Ma, together with a slow cooling or reheating pulse at ca. 59–10 Ma in the Yuku ore field. The Early Cretaceous rapid cooling is related to the coeval collisional tectonics of the East Qinling Orogen. The enhanced cooling at ca. 125–59 Ma is triggered by the post-collisional assembly of the North China and Yangtze Blocks, the subduction of Paleo-Pacific Plate, and the sinistral strike-slip motion of the nearby Tan-Lu Fault Zone. The slow cooling during ca. 59–10 Ma and the post-10 Ma enhanced cooling are correlated with the extensional tectonics derived by the subduction of Pacific Plate and the far-field effects from India-Eurasia collision. The Yuku area underwent lower exhumation in comparison to the nearby Shibaoguo and Huangbeiling areas in the Yuku ore field, which thus is helpful to the preservation of Mo deposits. The un-exhumated areas within 1.0 km at the inner and outer contact zones between the Yuku pluton and its wall rocks are postulated to be favorable sites for Mo prospecting. In addition, the un-exhumated areas surrounding other Late Mesozoic plutons in the Luanchuan region are also suggested to have high potential for Mo exploration. [ABSTRACT FROM AUTHOR]

Metal mobilization event was linked to shear-associated granodiorite magmatism. [Display omitted] • Um Samiuki volcanogenic massive sulfide deposit in Egypt's South Eastern Desert. • Zircon U-Pb and sulfide Re-Os dating reveal the genetic link with the host rocks. • Ore-hosted stratum formed ∼700 Ma, and a crosscutting granodiorite at 624 Ma. • Sulfide minerals show high Re-Os ratios and crustal isotope signature. • Ductile shearing formed discrete sulfide masses, followed by intermittent brittle deformation. • Ag-mineral inclusions in galena and solid solution in sulfides contribute to Ag budget. The Um Samiuki deposit in the South Eastern Desert of Egypt is a Kuroko-type volcanogenic massive sulfide deposit associated with arc-related bimodal volcanic rocks. SIMS U-Pb zircon ages of the host metavolcanic rocks and a crosscutting granodiorite intrusion are integrated with Re-Os isotopes of ore sulfides, allowing the determination of the genetic relationships between sulfide mineralization and host rocks to be determined. Zircon U-Pb dating reveals that the ore-hosted stratum of banded tuffs formed at ∼700.0 ± 7.3 Ma, whereas the granodiorite yielded a concordia age of 624.0±8.5 Ma. Sulfide mineral separates (pyrite, sphalerite, chalcopyrite) and sulfide mixtures from the massive ores have significantly high radiogenic Re-Os concentrations and ratios. Regression of seven 187Re/188Os-187Os/188Os data points with the corresponding uncertainty correlation values yields a 624±46 Ma age (2σ, MSWD = 0.56), with an initial 187Os/188Os ratio of 3.58±0.7, thereby pinpointing a distinctive crustal isotope signature. Evolution towards textural equilibrium by recrystallization, as revealed by grain growth and annealing textures in the ores, suggests that ductile shearing and penetrative deformation of the host metavolcanic/metavolcaniclastic rocks led to the formation of discrete sulfide disseminations and masses. Deformed, rolled and rotated pyrites in veins and tension gashes with or without quartz evidently suggests an intermittently rejuvenated brittle deformation regime superimposed on the early ductile deformation textures. Pyrite, galena, chalcopyrite, and sphalerite contain elevated Ag contents between 5 and 812 ppm. Two pyrite generations can be distinguished with the earlier one (Py1) having the highest Ag contents of all sulfides. Silver was released during replacement of Py1 by a late assemblage (Py2-galena-chalcopyrite-sphalerite) with some Ag incorporated into the late sulfides but most Ag was released and retained in discrete Ag minerals like cerveilleite, hessite and acanthite. Time-resolved analyses of LA-ICP-MS data reveal the presence of micron-scale Ag-bearing inclusions in galena while other base metal sulfides also contribute a notable part to the Ag budget of Um Samiuki ore. The new geochronological data integrated with results of the microscopic and microanalytical analyses of the sulfide phases provide an updated insight into a metal mobilization event in the Um Samiuki volcanogenic massive sulfides, roughly coincided with shear-associated granodiorite magmatism. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Hacipushanbei deposit represents a Triassic mineralization event in the EKO. • Fluid and geochemical data indicate a magmatic affiliation for the ore formation. • Fluid immiscibility occurred to promote precipitation of polymetallic sulfides. A recent mineral exploration programme in the East Kunlun Orogen (EKO) identified the new Hacipushanbei Pb-polymetallic deposit. The ores are hosted in faults in granitic rocks and are marked by high Pb grades up to 22.5 %. U–Pb dating of calcites associated with mineralization yields an intersection age of 208 ± 9 Ma, indicating a late Triassic mineralization event. Fluid-inclusion analysis reveals that the ore-forming fluids are characterized by medium-to-high temperature, medium-to-low salinity, and low density. Fluid boiling or immiscibility during ore-formation is also noted. Three sub-generations of pyrite (Py1-1, Py1-2, and Py2) are recognized in the early mineralization stages. In situ trace element analysis shows low Co and Ni contents in Py1-1 and Py1-2 but high contents in Py2. Conversely, Au and As concentrations are the highest in Py1-2. Variations in As contents are systematically coupled with Au. Additionally, sphalerite in the second stage contains higher amounts of Co, Cu, Cd, and In, via a wide range of isomorphic elemental substitutions of X4+(Sn4+ and Ge4+) + X3+(In3+, Sb3+, and Ga3+) + X+(Ag+ and Cu+) ↔ 4Zn2+ and the associated In enrichment. The average δ 34S values of in situ and single minerals of Py1-1, Py1-2, Py2, Sp2, Ccp2, and Gn3 are 2.3 ‰, 3.3 ‰, 2.6 ‰, 2.4 ‰, 2.2 ‰, and 0.9 ‰, respectively. These values display a trend of initial increase and then decrease, consistent with thermodynamic fractionation. These data collectively indicate that the ore-forming fluid originated from a deep-seated magma chamber, and subsequent fluid immiscibility led to the formation of high-grade ores. Given the conspicuous association of Pb-polymetallic deposits with magmatic rocks in the EKO, we envisage that our genetic model can be applied, to some extent, to evaluate the potential of some mineral exploration targets. [ABSTRACT FROM AUTHOR]

[Display omitted] • Four phases of deformation are recorded with the D3 event closely related to gold. • SHRIMP zircon U-Pb dating of granite dikes yields ages of 216 ± 3.0 Ma to 210 ± 9.7 Ma. • Ar-Ar dating of gold-related muscovite gives a mineralization age of 210.9 ± 1.6 Ma. • The Yangshan mineral systems comprise epizonal orogenic gold deposits. The West Qinling Orogen in central China resulted from Late Devonian to Triassic collisional orogenesis involving accreted terranes along the southwestern margin of the North China Block with subsequent ocean closure and collision of the South China Block with those terranes. The Yangshan gold district, with a pre-mining resource of more than 308 t gold, is situated along the Mianlue Suture Zone on the southern margin of the orogen. The gold orebodies are mainly controlled by the ENE-trending Anchanghe-Guanyinba Fault and its subparallel second-order faults. The relatively low pressure–temperature mineralization is dominated by disseminated pyrite, arsenopyrite, and stibnite hosted in phyllite and granite dikes, accompanied by intense muscovite-silica-carbonate alteration. Four major phases of deformation related to collisional tectonics are recorded in the Yangshan gold district. Early N-S-oriented compressional deformation (D1) is characterized by an alignment of muscovite, overgrowths on framboidal pyrite, and quartz veinlets. D2 is characterized by a series of continuous ENE-trending reverse faults and folds at multiple scales related to SSE-NNW-oriented compression. D3 is related to gold mineralization and is characterized by a series of ENE-trending, largely normal faults, formed during transtensional tectonics. D4 post-dates gold mineralization and is associated with the development of nearly N-S-trending, low-displacement normal faults. New high-precision SHRIMP zircon U-Pb dating of three types of granite dikes in the Yangshan gold district yields broadly coincident ages of 216 ± 3.0 Ma to 210 ± 9.7 Ma, which is a range identical to that of existing dates of 217–211 Ma for more regional granite magmatism in this district. New Ar-Ar dating of gold-related muscovite gives an age of 210.9 ± 1.6 Ma for the Yangshan gold deposit, indicating that hydrothermal activity overlapped or post-dated the final stages of granite intrusion. Pre-226 Ma peak metamorphism of the ore-hosting rocks occurred prior to extensional ductile shear deformation that is constrained by a published 40Ar/39Ar muscovite cooling age of 223 ± 2 Ma. In good agreement, U-Pb constrained ages of retrograde metamorphism and associated late magmatism of around 215 Ma are reported for rocks along the Mianlue Suture Zone. These geological and geochronological data suggest that relatively shallow-level gold mineralization was broadly coeval with Late Triassic transtensional, orogen-parallel deformation along the regional-scale fault system, late in the tectonic evolution of the West Qinling Orogen. This is consistent with its classification as epizonal orogenic gold mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magmatic and metamorphic columbite crystallized at 1359 ± 31 Ma, 346 ± 18 Ma and 284 ± 16 Ma, respectively. • The niobium in Bayan Obo is sourced from Mesoproterozoic carbonatite. • Local enrichment of niobium is attributed to the process of fenitization. • Nb and REE mineralization display spatial and temporal coupling in Bayan Obo deposit. The Bayan Obo deposit is world-famous for its giant rare earth reserves, and also accompanied with 2.2 Mt Nb 2 O 5 resources at an average grade of 0.13 %, renowned as the second largest Nb deposit globally. Previous studies have focused on the origin of carbonatite (igneous/sedimentary), and variation composition during evolution, as well as its super-enrichment of light rare earth elements (LREE), while the metallogenic mechanism of niobium is being overlooked despite the identification of plenty Nb-bearing minerals. In this study, we identify four types of columbite as major Nb-bearing minerals, instead of pyrochlore in the west pit of Bayan Obo. Detailed mineralogical study has revealed large primitive columbite (Clb1-I, 100–200 μm) is hosted in the coarse-grained Fe-dolomite carbonatite (FeO = 5.46–10.47 wt%), being an ideal target for future mineral beneficiation. Those columbites (Clb1-I) are featured by lowest Sr, Y, and ∑REE but enriched in iron in composition, revealing its magmatic origin. Sieve-textured columbite (Clb1-II, ∼100 μm) dispersed in the fluorination and chloritization dolomite carbonatite, with a U–Pb age of 1359 ± 31 Ma, contemporary with ages of the regional carbonatite magma intrusion and rift-related magmatism, indicating niobium being sourced from mantle-derived carbonatite. The occurrence of fluorite as inclusions in Clb1-I indicates the solubility of Nb was enhanced by fluxes, and the columbite saturation was easily achieved during the carbonatite magma evolution into ferroan carbonatite. Strong fenitization metasomatism further locally concentrated columbite either within the mineral assemblages of pyrite + phlogopite + allanite (Clb2) or in the mica-dominated fenite (Clb3), and crystallized at 346 ± 18 Ma and 284 ± 16 Ma, respectively. The latter metalogenetic epoch is accordant with late Permian granitic magmatism event (ca. 280 Ma) while the former age may attribute to its occurrences related to the early Paleozoic arc-continent collision. Differ from pristine columbite (Clb1-I and Clb1-II), the metamorphic columbite (Clb2 and Cl3, especially Clb3) are enriched in Ta (1803–4092 ppm), Y (560–2029 ppm) and ∑REE (720–6317 ppm) content, probably suggesting the highest degree of evolution. The similar metallogenesis framework between Nb and REE, combined with the coexistence of columbite and REE minerals assemblages, implies the spatial and temporal coupling of Nb and REE mineralization. This first innovative and systematic mineralogical and geochronological work directly constrains the nature of Mesoproterozoic mantle-derived carbonatite with fertile Fe and fluxes, and the Paleozoic and Permian fenitization metasomatism, are the major factors contribute to the metallogenic specialization of niobium in Bayan Obo. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Xiaolonghe and Lailishan Sn deposits in the Tengchong-Lianghe tin belt formed in oceanic subduction and continental collisional settings, respectively. • The Sn-related granitoids from the two deposits have very similar magma sources, melting temperatures, evolution processes, redox states, and volatile contents. • The specific mechanism triggering mantle upwelling could be the most significant difference between the formation of Sn-related granitoids in subduction versus collision processes. Magmatic-hydrothermal Sn deposits can develop in both subduction and collision settings. However, a systematic comparison of the geochemical fingerprints and petrogenetic evolution of Sn-related granitoids from both settings is still lacking. The Tengchong-Lianghe tin belt hosts numerous Sn deposits but of different metallogenic ages, such as the Xiaolonghe and Lailishan Sn deposits, which provide an ideal study area for addressing this issue. Zircon U–Pb dating suggests that the Xiaolonghe and Lailishan Sn-related granitoids were emplaced at 74.2–75.5 and 50.0–51.1 Ma, respectively. Given the initial India-Asia collision commenced at ca. 65–60 Ma, these ages, consistent with available Sn metallogenic ages, suggest the formation of the Xiaolonghe and Lailishan Sn deposits in subduction and collisional settings, respectively. New zircon and apatite compositions, and apatite Sr isotopic data, combined with previously reported whole-rock geochemical results, all indicate that the Xiaolonghe and Lailishan Sn-related granitoids share similar magma sources, evolution processes, redox states, and volatile contents. The presence of hornblende, high apatite Nd N /Nd N * (mostly > 1), and whole-rock evolutionary trends, together indicate that they represent fractionated I-type granites. Distinctly elevated apatite 87Sr/86Sr ratios (0.70988–0.71430) suggest that they originated from an ancient lower crust. Subsequently, they underwent an extensive fractional crystallization dominated by feldspar, as revealed by whole-rock, apatite, and zircon elemental variation trends. The low zircon Ce N /Ce N * (mainly < 200) and ΔFMQ (–1.9 to 1.7), together with elevated apatite F content (2.30–3.69 wt%), reveal that they crystallized from reduced and F-rich magmas. The relatively high whole-rock zircon saturation temperatures (mainly > 800 ℃) and Ba/Pb ratios imply that they were produced at a higher temperature by biotite-dehydration melting, which requires additional heat from the mantle. The specific mechanism that triggers mantle upwelling (oceanic slab subduction or break-off) could be the most significant difference between Sn-related granitoids formed during subduction and collision processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The granodiorite porphyry in the Xiayi Sn deposit formed at 138 Ma, determined by zircon U-Pb dating. • Cassiterite U-Pb dating indicates a Sn mineralization age of 136 Ma in the Xiayi Sn deposit, which is contemporaneous with the granodiorite porphyry. • Hf isotope analysis of zircon suggests the involvement of mantle materials during the formation of the granodiorite porphyry. • Trace element compositions of cassiterite reveal distinct roles of Ti, W, Fe, V, and Sc in the cathodoluminescence (CL) response. • Our research provides valuable insights into the extension of the southeastern coastal metallogenic Sn belt into western Fujian Province. The Xiayi Sn deposit, located in the Sanming city, southeast China, is the largest Sn deposit in Fujian province. The mineralization mainly consists of cassiterite-bearing veinlets and stockworks, and it is spatially associated with the granodiorite porphyry. Despite its economic significance, few studies have been carried out, and the mineralization age remains unknown. In this paper, we present the first geochronological data on the cassiterite and the associated granodiorite porphyry, Hf isotope of the zircon, and trace element compositions of cassiterite from the Xiayi Sn deposit. These data give precise age of the Sn mineralization and constrain its relationship with the granitic intrusion. Zircon U-Pb dating of the ore-related granodiorite porphyry yielded the age of 138.3 ± 1.8 Ma, which agreed well with the cassiterite U-Pb age of 136.5 ± 1.4 Ma, documenting the genetic link between the Sn mineralization and granitic magmatism. Zircon εHf(t) ranged from −4.5 to −1.8 with a weighted mean of −3.4 and the Hf model ages (TDM2) vary from 1.31 to 1.47 Ga with a mean value of 1.40 Ga. These data indicate that the granodiorite porphyry originates from the partial melting of the crustal materials of Mesoproterozoic basement and show the addition of mantle-derived materials, similar to typical Sn mineralized granite in the southeastern coastal tin belt and Nanling tungsten-tin belt. Besides, cassiterite from Xiayi deposit show clear CL-bright and CL-dark sector zonation in the cathodoluminescence images. LA-ICP-MS trace element analyses of cassiterites indicate a high Ti and Fe but low Nb and Ta contents in both CL-bright and CL-dark sector zones, while the W content is significantly high in the CL-dark zone and low in the CL-bright zone. Cassiterite trace element compositions together with the mineralization pattern and alteration assemblages indicate that Xiayi is a porphyry tin deposit. These results provide proof of the extension of the southeastern coastal Sn metallogenic belt and offer potential breakthroughs in tin deposit exploration in southwestern Fujian Province. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study is the first attempt of a systematic horizontal skarn profile in Beiya. • Two types of garnet have been distinguished in endoskarn and exoskarn. • The conditions and compositions of hydrothermal fluid in different environments vary. • The skarn mineralization age is restricted by crystallization age of garnet. Garnet is one of the most typical minerals in skarn deposits, and its texture and composition is a proxy for the changing physicochemical conditions. Thus, mineralogical and geochemical characterization of different garnet types can provide important information on the nature and evolution of ore-forming fluids. The Beiya gold-polymetallic deposit is China's largest skarn-type Au deposit with Au reserves of >380 t. Although several studies have addressed the skarn formation mechanism and nature of fluid evolution, a systematic study on the changes in the composition and texture of garnet from wall rocks to ore-related intrusion has not yet been attempted. In this work, we carry out a systematic investigation along a horizonal profile in the open pit of the Beiya deposit. Our results show that the garnet in the profile belongs to grossular-andradite solid solution series with all grains showing well-developed fine oscillatory zoning. The garnets are of two types: the first type (Grt I) formed within the endoskarn, is reddish to red with euhedral-subhedral megacryst structure (>10 mm) and has altered surfaces. The second type (Grt II) occur in the proximal exoskarn, is red to brown–red, euhedral-subhedral, with medium- to fine- grained structure (0.3–4 mm) and displaying oscillatory zoning. Unlike Grt I, hydrous minerals occur in the pores among Grt II garnets, such as calcite, quartz, epidote and chlorite. Also, calcite-chlorite vein, quartz vein and quartz-chalcopyrite-pyrite vein cuts the Grt II garnets. Grt I is dominantly grossular (Adr 14.88-43.58 Grs 55.25-82.87), depleted in the large ion lithophile elements (LILE), relatively enriched in high field strength elements (HFSEs) and enriched in heavy rare earth elements (HREEs) with negative Eu anomalies. Grt II is mostly andradite (Adr 62.18-98.91 Grs 0-36.22), depleted in the LILE and HFSE, enriched in light rare earth elements (LREEs) with slightly positive Eu anomalies. Here we selected Grt II for in-situ LA-ICP-MS U-Pb dating, since Grt I contains negligible uranium. The results yielded a lower intercept 206Pb/238U age of 35.3 ± 1.8 Ma (MSWD = 0.68, n = 23). The calculated oxygen isotopic compositions of hydrothermal fluids in equilibrium with two types of garnets range from 6.46 ‰ to 8.56 ‰ (average 7.89 ‰), which are within the range of values for magmatic fluids. We infer that the physicochemical conditions of the hydrothermal fluid changed from relatively reduced, nearly neutral, and low water/rock ratios to slightly oxidized, slightly acidic, and high water/rock ratios. The chlorine content in the fluid increased during garnet growth. The fluctuating compositions of garnets in the skarn suggest multistage ore-fluid activities and the fluid evolution provide insights into the ore-forming process. [ABSTRACT FROM AUTHOR]

[Display omitted] • A porphyry-epithermal Au system is developed in the Songshunangou district. • The Songshunangou porphyry-epithermal Au system formed in the Early Paleozoic. • The Songshunangou porphyry-epithermal Au system formed in a magmatic arc setting. The Songshunangou district is located in the central part of the North Qilian orogenic belt and hosts both the Eastern and Western deposits. The Western deposit is a porphyry-Au deposit, characterized by concentrated high-grade Au mineralization within a quartz-dioritic porphyry and occurs along the contact to basaltic andesite. Alteration is concentric with potassic alteration associated with high-grade Au mineralization in the core zone, while surrounding propylitic alteration is associated with an only lower-grade Au mineralization. Barren sericite-chlorite alteration is restricted to shallow zones above or partially overprinted the potassic alteration. Mineralization, including chalcopyrite, bornite, pyrite, magnetite, native gold with minor galena, sphalerite, hematite, and covellite, is observed as quartz-sulfide stockworks and fine-grained disseminations in different alteration zones. LA-ICP-MS zircon U–Pb dating of samples from the ore-bearing quartz-dioritic porphyry, the post-mineralization dioritic porphyry and the granodioritic porphyry in the Western deposit yield mean 206Pb/238U ages of 456.3 ± 2.0 Ma to 454.9 ± 2.4 Ma, and 449.5 ± 4.5 Ma to 448.3 ± 1.4 Ma, respectively. Pyrite from quartz – chalcopyrite – bornite veinlets in the Western deposit yields a Re-Os isochron age of 454.6 ± 3.7 Ma. In the Eastern deposit, which is an intermediate-sulfidation epithermal deposit hosted in basaltic andesite, sericite-chlorite alteration is associated with the mineralization. The mineralization is predominantly found within veins and disseminated, primarily composed of galena, sphalerite, native gold, tetrahedrite, and minor chalcopyrite, pyrite, and covellite. The alteration mineral assemblage comprises sericite, chlorite, Mn-calcite, quartz, calcite, and minor epidote. A Mn-calcite – quartz – polymetallic vein from the Eastern deposit yields a calcite Sm-Nd isochron age of 453.2 ± 5.8 Ma, suggesting that intermediate-sulfidation mineralization was coeval with the emplacement of the ore-bearing quartz-dioritic porphyry and the porphyry mineralization in the Western deposit. Based on these geologic features and geochronological data, we conclude that an early Paleozoic porphyry-epithermal Au system developed in the Songshunangou district, which formed in an arc setting associated with the northward subduction of the North Qilian Ocean beneath the North Qilian orogenic belt. The occurrence of an early Paleozoic porphyry-epithermal Au system in the North Qilian orogenic belt provides new insights for regional mineral exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Maoershi Sn polymetallic deposit was closely related to Indosinian granitic magmatism. • The W–Sn polymetallic deposit in the Dupangling region formed in an extensional tectonic setting after late Indosinian collision. Nanling is located in central South China and contains the most important area of W–Sn polymetallic deposits worldwide. However, a lack of geochronological data hinders our understanding of the timing and mechanisms of W–Sn mineralization in the Dupangling area of western Nanling. The Maoershi Sn polymetallic deposit is located in the western body of Dupangling complex pluton, and is a significant hydrothermal vein deposit. Cassiterite U–Pb dating shows that the Maoershi Sn mineralization occurred during the Late Triassic (206.2 ± 2.6 Ma). This age is different from the age of granite in the western Dupangling pluton and similar to the age of the eastern Dupangling pluton. The cassiterite is enriched in Sc (4.5105–18.4049 ppm), V (37.2267–88.9671 ppm), Nb (62.0104–194.1846 ppm), Ta (11.1965–85.6881 ppm), Hf (22.0511–30.7650 ppm), U (2.8870–17.9187 ppm), Th (0.0005–0.0908 ppm), Ti (3873–6170 ppm), and other high-field-strength elements. Based on Nb/Ta and Y/Ho ratios, and the W–Fe discriminant diagram, Sn and the other mineralizing materials were mainly derived from hidden Indosinian granitic rocks. Tungsten–Sn mineralization in the Dupangling pluton exhibits a clear spatial–temporal relationship with Indosinian granitic magmatism, and occurred in an extensional setting after the continent–continent collision that marked the late Indosinian Orogeny. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wolframite U-Pb dating recognized a mineralization event at ∼140 Ma, indicating that magmatism and tungsten mineralization in Dongshanwan are almost simultaneous. • The fluid-rock interaction had a significant influence on wolframite precipitation that provides sufficient Fe; the exsolved fluid interacted with the granite achieve more enrichment in Nb, Ta, Sn, and REEs than with the tuff. • The non-CHARAC behavior of Y/Ho and Zr/Hf in wolframite indicates that fluorine is involved in the migration and enrichment of W and other elements. The Southern Great Xing'an Range is a significant polymetallic metallogenic belt in Northeast China. The ages of granite related to tungsten mineralization have been well quantified, however, the timing and mechanism of quartz vein-type wolframite deposition remain unclear. Therefore, our study focused on the Dongshanwan tungsten deposit, representing a typical wolframite-bearing quartz vein-type deposit in the Southern Great Xing'an Range. Quartz vein-type tungsten mineralization was mainly contained in the Early Cretaceous granite porphyry, with few exceptions in the Permian tuff. Representative wolframite samples were collected from intragranitic (Wol-I) and intra-tuff (Wol-II) quartz veins for wolframite U–Pb dating, electron probe microanalysis (EPMA), and trace elemental analysis. Wolframite U–Pb dating recognized an Early Cretaceous mineralization event at 139–141 Ma, consistent with the previous Dongshanwan granite's ages (∼142 Ma) but much younger than tuff (∼260 Ma). All the wolframite samples belonged to the ferberite series (FeO/MnO = 4.0–6.9), which indicates a link to the highly fractionated granite. Wol-I showed high contents of Nb, Ta, Sc, and HREEs and a strongly negative Eu anomaly (0.02–0.29), while these elements in Wol-II were approximately one order of magnitude lower than in Wol-I and the Eu anomaly was highly variable (0.17–1.02). The redox characteristics reflected by the Eu anomaly of wolframite may correspond to the variations in oxygen fugacity. Based on petrology, geochemistry, and element mass migration, this study suggests that the granite porphyry and tuff in the Dongshanwan deposit contributed differently to the wolframite precipitation even if the ore-forming fluids were of a common magmatic-hydrothermal origin. The exsolved fluid reserved in the closed system interacts with granite to achieve continuous enrichment in Nb, Ta, Sn, and REEs and accepts external Fe supply from granite alteration to precipitate Wol-I. In contrast, the fluids in relatively open and non-granitic systems have lower Nb, Ta, Sn, and REEs than the former, and Fe supply depends on the alteration of tuff. The abundance of fluorite and the non-CHARAC (CHArge-and-RAdius-Controlled) behavior of Y/Ho and Zr/Hf in the wolframite suggested that fluorine plays an important role in the migration and enrichment of tungsten and other elements during tungsten mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • An epithermal gold deposit with fluid boiling as the primary precipitation mechanism. • Formed around 97.5 Ma in the early Late Cretaceous. • Formed in an arc-extensive environment associated with the slab rollback of the subducted Palaeo-Pacific Plate. The origin and evolution of the newly discovered Yidonglinchang gold deposit in the Lesser Xing'an Range, Northeast China, remain poorly understood. This article focuses on the investigations of the geological characteristics, fluid inclusions, H-O-S-Pb stable isotopes and geochronology of the deposit. The Yidonglinchang gold deposit is mainly controlled by NEE-trending faults, and the ore bodies are present in volcanic rocks of the Early Cretaceous Ningyuancun Formation (K 1 n). Silicification, pyritisation, and argillization zones develop sequentially from near the ore center outwards. The ore minerals mainly include electrum and argentite. The gangue minerals are mainly quartz, calcite, and a small amount of sericite, plagioclase and adularia. The main gold-bearing minerals are quartz and calcite. The primary fluid inclusion types in quartz are pure-liquid-phase, gas-rich-phase, and liquid-rich-phase inclusions. Most of the inclusions are classified as a H 2 O-NaCl system which were formed under low-temperature, low-salinity conditions, indicating that Yidonglinchang is an epithermal gold deposit. The occurrence of boiling fluid inclusion assemblage indicates that the fluids underwent decompression boiling. Sm-Nd dating of calcite from the main ore-forming stage yields an age of 97.5 ± 2.3 Ma, which is interpreted as the timing of mineralisation. Zircon U-Pb dating of dioritic porphyrite yields ages of 98.8 ± 1.1 and 98.0 ± 1.3 Ma, which are consistent with the mineralisation age, suggesting a potential genetic link between the intrusive rocks and the ore formation. H-O-S-Pb isotopic compositions indicate that the ore-forming fluids were magmatic water during the early mineralisation stage, with the addition of meteoric water during the late stage. These isotopic compositions are also indicative of an origin of the ore-forming materials from the mixed crustal and mantle components. The mineralisation of the Yidonglinchang gold deposit was related to the slab rollback of the subducted Palaeo-Pacific Plate in the early Late Cretaceous. [ABSTRACT FROM AUTHOR]

[Display omitted] • We conducted fluid inclusion and isotopic analyses at the Aerhada Pb–Zn–Ag deposit. • Sphalerite Rb–Sr and zircon U–Pb dating were also employed. • Ore-forming fluids evolved from NaCl–H 2 O–CH 4 ± CO 2 system to NaCl–H 2 O system. • Ore-forming materials originated from concealed biotite granite and wall rocks. • Aerhada is a magma-related hydrothermal deposit formed in an extensional setting. The Aerhada Pb–Zn–Ag deposit is on the western margin of the Great Xing'an Range in NE China. Prior studies on this deposit lack information regarding precise mineralization age and convincing genetic interpretation, which limits both the prospecting at Aerhada and the reconstruction of the regional metallogenic evolution. Based on a detailed field investigation and microscopic observation, in this study, our aim was to determine the origin and evolution of the hydrothermal system and the timing of magmatism and mineralization, as well as to develop a possible metallogenic model, by revealing information regarding the mineralization paragenetic relationship, fluid inclusions, H–O–C–S–Pb isotopes, and sphalerite Rb–Sr and zircon U–Pb ages. Three successive mineralization stages were recognized: stage I quartz-arsenopyrite-pyrite, stage II quartz-sphalerite-galena, and stage III fluorite-calcite-pyrite. Four types of fluid inclusions were also identified in host minerals: CH 4 -rich two-phase, halite-bearing, vapor-rich two-phase, and liquid-rich two-phase. Fluid inclusion and microthermometric results showed that the homogenization temperatures were 287–341 °C for stage I, 237–291 °C for stage II, and 162–230 °C for stage III, with respective salinities of 1.7–40.2 wt%, 6.7–10.9 wt%, and 4.2–8.8 wt% NaCl equivalent. The δ18O fluid and δD fluid values of quartz in stage I (δ18O fluid = 8.6–10.3 ‰, δD fluid = -126.6 to −124.3 ‰) indicated that initial magmatic water interacted with organic strata, while decreasing the values of quartz in stage II (δ18O fluid = 3.9–6.8 ‰, δD fluid = -129.1 to −127.6 ‰) and calcite in stage III (δ18O fluid = -3.5 to −1.0 ‰, δD fluid = -115.5 to −113.4 ‰), showing a trend of dilution and cooling by meteoric water. The negative δC fluid values (δC fluid = -15.9 to −12.6 ‰) of quartz fluid inclusions from stages I and II emphasize that organic carbon was added to the hydrothermal system through water–rock interactions. The δ34S values (δ34S sulfides = 1.2–7.5 ‰) and lead isotope data of sulfides (206Pb/204Pb = 18.153–18.684, 207Pb/204Pb = 15.370–15.750, 208Pb/204Pb = 37.653–39.301), coupled with those of the hidden biotite granite and Devonian strata, indicate that the ore-forming material was primarily derived from magma and wall rocks. The sphalerite samples produced a Rb–Sr isochron age of 154.1 ± 3.5 Ma (2σ, MSWD = 0.82, n = 8), which was like the zircon U–Pb age of biotite granite (156.3 ± 1.4 Ma, 2σ, MSWD = 0.89, n = 14). Combining the alteration pattern, fluid inclusions, and isotopic and geochronological studies, it was concluded that Aerhada is a magma-related hydrothermal Pb–Zn deposit formed under the post-collision extension setting following the Mongol–Okhotsk Ocean closure during the Late Jurassic period. The proposed metallogenic model is expected to assist in the exploration and development of polymetallic mineralization in the Great Xing'an Range. [ABSTRACT FROM AUTHOR]

[Display omitted] • A giant porphyry-skarn-epithermal Mo-W-Cu-Zn-Pb-Ag metallogenic system is recognized in the Nannihu ore field. • New geochronological data reveal that the porphyry-related metallogenic system formed in the Early Cretaceous (145–139 Ma). • The episodic magmatism and mineralization resulted in the remarkable enrichment of mineral resources at Nannihu. • The model of this porphyry-related metallogenic system has a significant implication for mineral prospecting in the area. The southern North China Craton owns substantial Mo, W, Zn, Pb, Cu, and Ag resources, and most of them are hosted in hydrothermal deposits that may co-exist in the same ore field. However, the relationship between the different types of deposits is not well-constrained. To better understand this, here we present a comprehensive geological, geochronological, and pyrite geochemical study on the Nannihu ore field in the Luanchuan district. The Nannihu ore field is largely represented by the Nannihu Mo-W deposit, Luotuoshan Zn-Cu-W deposit, and Lengshuibeigou Pb-Zn-Ag deposit. Mo-W mineralization at Nannihu occurs in the contact zone between the Nannihu intrusion and the wall rocks, showing typical characteristics of the porphyry-type deposit. Three paragenetic stages are recognized at Nannihu, including quartz-potassium feldspar stage, quartz-sulfide stage, and quartz-carbonate stage. The Zn-Cu-W orebodies at Luotuoshan are mainly layered or lens-like, occurring within the skarn zones in the Luanchuan Group. Skarn stage, polymetallic sulfide stage, and carbonate stage are revealed at Luotuoshan. Pb-Zn-Ag mineralization at Lengshuibeigou is characterized by banded sulfide veins that are hosted in the NNE-trending fault zone. Three paragenetic stages are developed at Lengshuibeigou: quartz-pyrite stage, quartz-polymetallic sulfide stage, and quartz-carbonate stage. New geochronological data confirm that the Nannihu intrusion was formed by at least two phases of magmatism including the granite porphyry (zircon U-Pb age of 145 ± 2 Ma) and the porphyritic monzogranite (zircon U-Pb ages of 142 ± 1 Ma and 140 ± 1 Ma), which accompanied by two episodes of Mo mineralization at the Nannihu deposit identified by molybdenite Re-Os dating (144.9 ± 0.7 Ma and 142.8 ± 0.6 Ma). The Luotuoshan deposit and Lengshuibeigou deposit formed at 141 ± 1 Ma to 140 ± 1 Ma and 140 ± 3 Ma to 139 ± 3 Ma revealed by U-Pb dating of garnet and monazite, respectively, which are contemporaneous with the late episode of the Nannihu intrusion and Mo mineralization. Pyrite grains of the three deposits have Co/Ni ratios higher than 1, suggesting a unified magmatic-hydrothermal origin for them. Pyrite from Nannihu and Luotuoshan is enriched in Co, Ni, Se, Mo, Mn, and Bi, whereas pyrite from Lengshuibeigou contains high Zn, Pb, As, Cu, Ag, and Au. The regular elemental distribution of pyrite in the Nannihu ore field is consistent with that of typical porphyry-related systems worldwide. Collectively, the Early Cretaceous magmatic rocks and diverse deposits in the Nannihu ore field make up a giant magmatic-hydrothermal Mo-W-Cu-Zn-Pb-Ag metallogenic system, with the porphyry, skarn, and epithermal types of mineralization displaying a zonation from inside to outside. The multi-episode magmatism and mineralization could result in the remarkable enrichment of mineral resources. The close spatial relationship among different types of mineralization in the Nannihu ore field has a significant implication for porphyry-related mineral prospecting in the southern NCC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Precise W mineralization ages of 227.9 ± 2.3 and 225.6 ± 3.0 Ma. • Separate W and Au mineralization events in the Zhaishang deposit. • Contrasting physical–chemical conditions for W and Au mineralization. The West Qinling Orogen is an important Au-W ore belt; however, the spatio-temporal and genetic relationships of W and Au ores remain unclear. This study takes the Zhaishang deposit, one of the largest Au-W deposits in the West Qinling Orogen, to trace their connections. The geological observation reveals that high-grade W ores are commonly characterized by extensional hydrothermal veins. In contrast, high-grade Au ores are hosted by breccia zones, which cut the W ore-controlling structures, even though the W and Au ores overlap locally. The mineral assemblages of W ores associated with carbonatization and silicification consist of scheelite and pyrite with few polymetallic sulfides, in contrast to the abundance of polymetallic sulfides and native gold in Au ores linked with silicification. Textural and in situ trace element analyses reveal that the scheelites show a decrease in Na, U, Mo, Nd, and calculated Eu anomaly values and an increase of Th concentrations and Ce anomaly values from early- to late-generation scheelites. This finding, in conjunction with mineral assemblages and previous thermodynamic modeling, suggests a decrease in salinity and oxygen fugacity (f O 2) of the oxidized ore-forming fluids of W mineralization, as opposed to the reduced fluids of Au mineralization. The plots of scheelite at Zhaishang in the ternary LREE-MREE-HREE diagram are compatible with those of W deposits related to magmatic-hydrothermal fluids. In situ U-Pb dating of scheelite from W ores constrains the precise timing of W mineralization at ca. 227.9 ± 2.3 and 225.6 ± 3.0 Ma in a collisional orogenic setting. The unequivocal crosscutting relationship, contrasting mineral assemblages, and physiochemical conditions suggest that the W and Au mineralization at Zhaishang are due to two separate mineralization events. The identification of overlapped W and Au mineralization events at Zhaishang is crucial for guiding the regional exploration of W and Au deposits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two episodes of garnet and Fe mineralization were identified at Jia'erbasidao Fe deposit. • The 1st garnet generation was formed at 270.6 Ma and skarn related. • The 2nd garnet generation was formed at 248.3–246.0 Ma and skarn related. Over a hundred iron ore occurrences have been discovered in the Chinese Altay Orogenic Belt (AOB), which is a key Fe-ore belt in NW China. In the Jia'erbasidao ore district, Fe skarn mineralization was mainly developed along the contact zone between biotite granite and the marble of Altay Formation, which is different from most Fe mineralization (non-skarn contact zone) in the Chinese AOB. Two generations of garnet (Grt1and Grt2) have been identified to be related to the two stages of Fe-ore formation at Jia'erbasidao, and Grt1 and Grt2 can be further divided into Grt1a, 1b and Grt2a, 2b, respectively. Our U-Pb dating indicates that the biotite granite and garnet from prograde skarn stage 1 (Grt1a) were formed at 275.6 ± 3.1 Ma and 270.6 ± 4.4 Ma, respectively. The mineralized biotite granite is metaluminous to peraluminous, LREE-enriched and HREE-depleted. Meanwhile, two Grt2a samples from the prograde skarn stage 2 yielded lower intercept 206Pb/238U ages of 248.3 ± 2.9 Ma and 246.0 ± 6.0 Ma, respectively. Grt1 and Grt2 may have formed from different ore-forming fluids: Grt1a was precipitated from a LREE-depleted, near neutral and low f O 2 fluid (δEu = 1.92–2.84); Grt1b and magnetite (Mag1) were precipitated from the same fluid with higher f O 2 (δEu = mostly 1.22–2.63); Grt2a was precipitated from a fluid with relative LREE enrichment, relatively lower pH and higher f O 2 (δEu = 0.98–1.69); Grt2b and magnetite (Mag2) was formed from a fluid that was HREE-enriched, near neutral, and higher f O 2 (δEu = 0.76–1.09). Our study shows a two-stage Fe mineralization at Ja'erbasidao, including the Early Permian Fe skarn mineralization and the Early Triassic skarn mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Garnet U-Pb dating yielded a lower intercept 206Pb/238U date of 277.5 ± 8.7 Ma. • Magnetite provides a good object for the study of the Fe mineralization process. • Three magnetite types were identified in the Huogeqi Fe deposit. • Geochemical features of the magnetite prove the affinities to skarn-type deposit. The Huogeqi Fe polymetallic deposit, which contains 48.17 Mt Fe, occurs in tremolite-diopside rocks of the Neoproterozoic Langshan Group in the north China. This study focuses on the magnetite mineralogy, texture and chemical composition, and U-Pb geochronology of garnet associated with magnetite and zircon from the granitoid related to mineralization in order to constrain the origin of Fe mineralization in Huogeqi deposit. LA-ICP-MS U-Pb dating of magnetite-bearing garnets yields a lower intercept age of 277.5 ± 8.7 Ma, which is coeval with the emplacement age of the mineralized-related granitoid (275.3 ± 1.3 Ma). Three types of magnetite were formed in the Huogeqi deposit, including Mt-A (coarse-grained disseminated), Mt-B (stratiform and fine-grained dense disseminated), and Mt-C (massive). The Mt-A can be subdivided into high-Ti Mt-A1 and relatively low-Ti porous and fractured Mt-A2. The Mt-B can be subdivided into porous Mt-B1 with relatively high V and low Ti contents, dark porous Mt-B2 with a relatively low V contents, porous inclusion-rich Mt-B3 with low Fe and V contents, and high Si and Mg contents, and less-porous Mt-B4 with low Si and Mg contents. The Mt-C includes porous Mt-C1 with a low Ti contents and high Si, Al, Mn contents and less-porous Mt-C2 with low Si, Al, and Mn contents. The decreasing Ti and V contents in the subsequent magnetite types indicate progressive cooling of the mineralizing fluid, increasing oxygen fugacity, and more intense fluid-rock interaction. Dissolution and re-precipitation played an important role in the formation of different generations of magnetite of Mt-B and Mt-C. The magnetite from Huogeqi deposit has a high Ni/Cr mass ratio, a high Fe content, and a high (Ca + Al + Mn) value, and a low V content, a low Ni/(Cr + Mn) mass ratio, and a low (Ti + V) value. These geochemical characteristics indicate that the magnetite has a hydrothermal origin in a skarn-type deposit, which is related to Early Permian magmatism in the Langshan area in north China. [ABSTRACT FROM AUTHOR]

[Display omitted] • New U-Pb geochronology and trace element data of hydrothermal rutile and titanite were obtained. • The Chaihulanzi deposit is a subduction-related orogenic gold deposit. • The northern NCC has exploration potentials for Early Permian lode gold deposits. The Chifeng-Chaoyang region, located along the northern margin of the North China Craton, is an important gold producer in China, with a proven gold reserve of about 500 tons. Most gold deposits are fault-controlled and formed in the Mesozoic, but the absolute ages of gold mineralization in this region have not been well constrained due to the lack of suitable dating minerals. This study presents in situ U-Pb ages of hydrothermal rutile and titanite for the Chaihulanzi gold deposit and obtains a distinctive age. The Chaihulanzi deposit (∼27 t Au) is located in the western portion of the Chifeng-Chaoyang region and mainly hosted in the carbonaceous mica schist of the Neoarchean-Paleoproterozoic Jianping Group along NW to NWW striking faults. It contains auriferous quartz veins and disseminated ores in hydrothermal alteration zones, with pyrite and pyrrhotite as the predominant ore minerals. Based on field and petrographic observations, four stages of mineralization process can be identified, involving stage I quartz-pyrite, stage II quartz-pyrite-pyrrhotite-chalcopyrite, stage III quartz-polymetallic sulfides, and stage IV quartz-calcite. Stage II represents the main gold stage and contains abundant hydrothermal rutile and titanite, which are intergrown with pyrite, pyrrhotite and native gold. Rutile grains have high contents of V, Nb, Fe, Cr, W and low contents of Zr and yield a Tera-Wasserburg lower intercept age of 285.4 ± 8.5 Ma (n = 37, MSWD = 3.9). Titanite grains show low Th/U and La/Yb ratios (0.03 to 0.66 and 0.26 to 3.98, respectively) and flat chondrite-normalized REE patterns (LREE/HREE = 0.88–5.72, Eu/Eu* = 0.71–1.71), with a Tera-Wasserburg lower intercept age of 282.3 ± 3.4 Ma (n = 20, MSWD = 2.1). Combined with the emplacement age of a post-ore mafic dyke (ca. 275.5 Ma), the timing of the Chaihulanzi deposit can be constrained to Early Permian, representing a new gold mineralization epoch in the Chifeng-Chaoyang region. On the basis of available geological and geochronological evidence, the Chaihulanzi deposit can be classified as an orogenic gold deposit formed during the southward subduction of the paleo-Asian Ocean. These new findings likely have important implications for future regional gold exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zircon U-Pb dating results refine the emplacement age of the Xikeng pluton at 232.2 ± 1.1 Ma. • Cassiterite and wolframite U-Pb dating constrains the timing of W-Sn mineralization from Xigkeng deposit at 228.4 ± 0.90 Ma and 227.8 ± 1.60 Ma, respectively. • Source of magmatic materials was derived from reworking of crustal materials under an extensional setting. The Chongyi–Shangyou–Dayu ore-concentrated district represents one of the most important wolframite production bases in China, and most of the W-Sn deposits formed in the early Yanshanian period. The Xikeng quartz vein-type W-Sn deposit is located spatially not far from the Triassic Keshuling granitic pluton. The deposit contains 43 ore-bearing quartz veins, in which the ore minerals are mainly cassiterite and wolframite. These ore veins are concentrated in the Sinian metasandstone and sandy slate of the Laohutang Formation and extend down to the top of the concealed granite. The concealed intrusion is composed of medium- to fine-grained muscovite granites, which relate to the Indosinian Keshuling granite, according to geophysical data. Zircon grains from the concealed Xikeng granitic intrusion have a concordant U-Pb age of 232.1 ± 1.1 Ma (MSWD = 0.9). The zircon εHf(t) values range from −11.0 to −7.9, indicating primary reworking of the ancient crustal materials. Wolframite and cassiterite grains yield Tera-Wasserburg concordia intercept ages of 228.4 ± 0.9 Ma (MSWD = 1.2) and 227.8 ± 1.6 Ma (MSWD = 0.3) for the Xikeng deposit, respectively. These data demonstrate that the Indosinian W-Sn mineralization events were genetically related to granitic magma activities that share similar magmatic sources with the Yanshanian W-Sn mineralization-associated granitic intrusions. Combined with previous robust granitic and metallogenic ages, this paper identifies a new Indosinian W-Sn mineralization event in southern Jiangxi Province, Nanling Range. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal rutile formed in a magmatic-hydrothermal system. • Dashuigou Te-Bi deposit formed at the Oligocene (32.4 ± 3 Ma). • Te-Bi mineralization related to the Eocene-Oligocene alkaline magmatism. The Dashuigou deposit, located in the transitional zone between the Yangtze craton to the east and the Songpan-Ganze orogen to the west, is the world's only known deposit where tellurium and bismuth are exploited as primary products. The Te-Bi orebodies mainly occur as the dolomite-tetradymite and Te-bearing pyrrhotite veins in Triassic low-grade metamorphic rocks. The ore minerals mainly consist of tetradymite, tsumoite, tellurobismuthite, pyrrhotite, and chalcopyrite. While mineralogy and geochemistry of the ores in the Dashuigou deposit have been well documented in the past decades, the age of the Te-Bi mineralization in the Dashuigou district is not well defined due to lack of both suitable dating mineral and chronometer, and thereby impedes further understanding on its ore genesis. Hydrothermal rutile coeval with tetradymite has been identified in this study from a high-grade dolomite-tetradymite vein in the Dashuigou deposit. This rutile is closely associated with tetradymite, tsumoite, Te-bearing pyrrhotite, and contains many tiny tetradymite inclusions. Here, we present the first in situ trace element compositions and U-Pb age of these rutile crystals using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The rutile is enriched in V, Nb, Ta, Sn, and Cr, but has low contents of As, Sb, and W, indicating a magmatic origin. U-Pb dating on rutile demonstrates a well-constrained age of 32.4 ± 3 Ma, which is interpreted as the timing of Te-Bi mineralization for the Dashuigou deposit. This new age provides the first evidence suggesting that the Dashuigou deposit is contemporary with regional Eocene-Oligocene alkaline magmatism and related metallogenic event in Sanjiang region. Compared with the Beiya Te-Bi-bearing porphyry Cu-Au and Yao'an Au deposits in the alkaline magmatic belt, we propose that the Dashuigou Te-Bi deposit was likely product of a concealed alkaline magmatic-hydrothermal system. This study also demonstrates the rutile U-Pb geochronology being a powerful tool for dating unusual ore systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dafang granitoid zircon U-Pb ages related to coeval magmatic and metallogenic events. • Dafand granitoid mainly derived from Paleoproterozoic middle-lower crust. • Pb-Zn and W-Sn metallogenic variations are determined by magmatic source, redox state and evolution degree. • Oxidized and reduced magmas related to Pb-Zn and W-Sn deposits, respectively. The Nanling Metallogenic Belt (NMB) in South China contains huge amounts of Middle to Late Jurassic granitoid-related polymetallic Pb-Zn and W-Sn deposits. Whether there is a link between granitoid genesis and mineral species and what specific factors control the metallogenic specialization remained unclear. Herein, we presented a systematic investigation on the Dafang Pb-Zn ore-causative intrusion, and then placed it into the compiled comprehensive dataset of the NMB ore-hosting granitoids aiming to reveal the magmatic control on the Pb-Zn and W-Sn metallogenic variations in South China. Our results illustrate that the Dafang granitoid is potassic, alkaline (Na 2 O + K 2 O: 5.84 % to 7.87 wt%) and meta-luminous (A/CNK: 0.75 to 1.01), with middle SiO 2 content (60.59–65.15 wt%), displaying an analogous nature of I-type granitoids. Trace elements of all samples are characterized by a significant enrichment in LREEs, Pb, and K, and a strong depletion of HREEs, HFSEs as well as Ba. Further zircon U-Pb dating yields a concordant age of 157.0 ± 0.8 Ma (MSWD = 1.1), consisting with the Jurassic magmatic-hydrothermal activities in the NMB. Their negative ε Hf (t) values (−6.7 to −10.2) and two-stage Hf model ages (1.6 to 1.7 Ga) suggest that the Dafang granitoid intrusion was generated from the partial melting of a Paleoproterozoic middle-lower crust. By comparing the Dafang with other NMB ore-causative granitoids in the comprehensive dataset, we investigated two types of ore-causative granitoids, i.e., the Pb-Zn- and W-Sn-mineralized granitoids, with distinct magmatic source, redox state and evolution degree. The Pb-Zn-bearing granitoids predominantly generated from amphibolite with a high oxygen fugacity (Ce4+/Ce3+: average 104.8, n = 55) and low differentiation degree (Rb/Sr: average 0.8, n = 60; Nb/Ta: average 12.5, n = 62). In contrast, the W-Sn metallogenic granitoids originated from metasedimentary rocks with a relatively lower oxygen fugacity (Ce4+/Ce3+: average 46.7, n = 258) and higher differentiation degree (Rb/Sr: average 59.0, n = 139; Nb/Ta: average 5.3, n = 156). Collectively, we conclude the Pb-Zn and W-Sn metallogenic variations in the NMB (South China) are jointly determined by magmatic sources, oxygen fugacity and differentiation degree. [ABSTRACT FROM AUTHOR]

[Display omitted] • Redefined uranium ages at 131-127 Ma vs. previous estimates at 122-80 Ma. • At least one mineralization event emerged after solidification of volcanic caldera. • The post magmatism was likely the 'heat engine' driving hydrothermal convection. • Apatite U-Pb geochronometer: precise tool for dating hydrothermal uranium deposits. The Xiangshan volcanic-related uranium ore field, located in the Ganzhou-Hangzhou Uranium-Polymetallic Metallogenic Belt (GHMB) in South China, has been the country's largest historic uranium producer. Although this ore field has been intensely studied for decades, the absolute age of uranium ore formation was still debated. Conventional U-Pb dates on U-minerals (i.e., pitchblende, brannerite) and Ar-Ar dates on associated alteration minerals (i.e., illite) from different uranium deposits yield a wide range of ages (122 to 85 Ma). The uncertainty regarding the exact timing of uranium mineralization at Xiangshan has limited the development of accurate ore genesis models and precluded a better understanding of the links between metallogenesis and regional-scale geodynamics during the Cretaceous-Tertiary period in South China. In this work, we focus on applying in-situ LA-ICP-MS U-Pb geochronology to magmatic and hydrothermal apatite from two typical uranium ore deposits at Xiangshan, intending to indirectly constrain the exact timing of uranium mineralization and reconstruct the magmatic-hydrothermal history. U-Pb age determinations on magmatic zircon and apatite from the three types of ore-hosting volcanic rocks yielded precise crystallization ages of 133 to 136 Ma and 135 to 140 Ma, respectively. These results are identical within uncertainty to previously reported U-Pb dates obtained in the study area, and thereby tightly constrain the emplacement age of the Xiangshan volcanic complex that hosts uranium deposits. Moreover, the potassium feldspar-biotite Ar-Ar dating for the major volcanic rocks demonstrates that these host rocks were cooled and completely solidified through the biotite/potassium feldspar closure temperature (below 300 °C) at 133–131 Ma. Subhedral or anhedral aggregates of hydrothermal apatite ubiquitously formed in the high-grade uranium ores at the Shannan and Zoujiashan deposits and are commonly intergrown with fluorite, illite and uranium minerals. Relative to magmatic apatite from the host rocks, the hydrothermal apatite is typically characterized by much higher U and Th contents, depletion of LREEs, enrichment in HREEs and a much more pronounced negative Eu anomaly. As such, the hydrothermal apatite is unequivocal of hydrothermal origin and formed synchronously with uranium mineralization. LA-ICP-MS U-Pb dating of these hydrothermal apatite crystals yielded an absolute 206Pb/238U age of 126.7 ± 0.6 Ma for the Shannan deposit and 131.3 ± 7.2 Ma for the Zoujiashan deposit. The new ages are much older (>10 Ma) than those previously reported ages on ore or gangue minerals such as pitchblende and illite. Thus, one unidentified mineralization event likely occurred at ca. 131–127 Ma, soon after solidification and subsequent brittle deformation or faulting within the volcanic caldera. We, therefore, proposed that volcanic magmatism was highly likely to be the 'heat engine' driving hydrothermal fluid convection and possibly provide the essential conditions (i.e., magmatic fluids, U sources) for the formation of the U mineralization. Another implication of this study is that dating hydrothermal apatite with high U concentrations associated with uranium mineralization could be considered a complementary geochronological tool in the study of analogous hydrothermal uranium deposits worldwide. [ABSTRACT FROM AUTHOR]

[Display omitted] • Precise geochronology define the magmatism and mineralization age. • The Late Triassic weakly Mo mineralization and Late Jurassic Ag–Pb–Zn mineralization. • The in situ Sulfur isotope data herein confirm the sulfur was mainly derived from a magmatic source. The large-scale Meng'entaolegai Ag–Pb–Zn polymetallic deposit is located in the Great Hinggan Range metallogenic belt, northeastern China. To better understand the formation of the Meng'entaolegai deposit, we present in situ S isotope data, zircon U–Pb isotope data, sulfide Rb–Sr data, and molybdenite Re–Os data for the units associated with the deposit and surrounding regions. In situ analyses show that the δ34S values of the sulfides (galena, sphalerite, and pyrite) vary from + 2.4‰ to + 6.6‰ (mean = +4.7‰, n = 60). The data herein confirm that the sulfur was mainly derived from a magmatic source. Zircon U–Pb dating of the medium- to coarse-grained monzogranite, plagiogranite, and fine-grained monzogranite from the Duerji batholiths and granodiorite and monzogranite from the Meng'entaolegai deposit yield weighted mean ages of 244.3 ± 1.7, 243.0 ± 2.1, 151.8 ± 1.5, 232.6 ± 2.2, and 223.1 ± 2.3 Ma, respectively. The Meng'entaolegai deposit yields a molybdenite Re–Os age of 229.5 ± 1.5 Ma, but sulfide Rb–Sr dating yields an isochron age of 147.2 ± 2.3 Ma. These new age data have revealed that the Meng'entaolegai polymetallic deposit formed during two mineralization episodes: an early episode at 230 Ma and a second episode at 147 Ma. The Late Triassic hydrothermal activity and weakly Mo mineralization formed in an extensional setting after the final closure of the Palaeo-Asian Ocean. The Late Jurassic hydrothermal activity and Ag–Pb–Zn mineralization formed in an extensional environment related to the Mongol–Okhotsk Ocean, but these exposed granitic rocks are unlikely to be related to the Ag–Pb–Zn mineralization, suggesting that more research is needed on the magmatic hydrothermal activity within the study area. [ABSTRACT FROM AUTHOR]

[Display omitted] • Yield the age of rutile and sericite to determine the absolute age of mineralization in gold deposits is feasible. • Hydrothermal rutile and sericite paragenesis with native gold are identified from auriferous quartz veins. • New U-Pb rutile and Rb-Sr sericite geochronology confirm multistage gold mineralization in the Liling goldfield. The Liling goldfield located in northeastern (NE) Hunan contains >200 tons of proven gold reserves. The gold mineralization age in Liling has long been controversial due to the lack of datable minerals. In this study, petrographic observations indicate that hydrothermal rutile and sericite were precipitated with auriferous pyrite/arsenopyrite in the ore veins. The electron probe microanalysis (EPMA) results show that the sericite from ores and the sericite from Neoproterozoic slate display distinct compositions (Especially Al, K, and Ti). The high W (1,081–36,456 ppm) and low Zr (21.35–288.7 ppm) contents of the rutile suggests a hydrothermal origin. We reported new laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb ages of ore-stage hydrothermal rutile (415.2 ± 8.3 Ma) for the Tuanshanbei gold deposit, and sericite Rb-Sr ages (417.6 ± 12.9 Ma and 216.9 ± 7.8 Ma) for the Tuanshanbei and Yanlinsi gold deposits in the goldfield. The new data confirm that multistage gold mineralization has occurred in the Liling goldfield, and falls within the generally accepted timing (ca. 430–400 Ma and 250–200 Ma) of gold mineralization in the Jiangnan Orogen. Integration of geological characteristics, tectonic setting, and geochronology of the Liling goldfield suggest two Au mineralization episodes, which occurred in the Late Silurian-Early Devonian intracontinental orogeny and Triassic intracontinental orogeny, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Incorporation of REE and U into andradite mainly follows coupled YAG-type substitution mechanism and the coupled substitution of [U4+]VIII + 2[Fe3+, Al3+]Ⅳ – [Ca2+] – 2[Si4+]Ⅳ in the dodecahedral position, respectively. • During skarn formation, the fluid evolved from pore fluid-mixed, through magmatic-hydrothermal dominated, to meteoric water influx. • The ages of andradite samples indicate that the skarn ore formation is coeval with associated granodiorite intrusions. The Chengmenshan Cu-Au deposit is a typical porphyry-skarn deposit in the Middle-Lower Yangtze River Valley Metallogenic Belt (MLYRMB), developing abundant oscillatory zoned andradite. However, the physiochemical conditions, hydrothermal evolution and age of skarn formation is unknown. This paper presents BSE image, EMPA point analyses, LA-ICP-MS point analyses and mapping, U-Pb isotope data for andradite from the Chengmenshan Cu-Au deposit. From core to rim, three generations of andradite could be identified (Grt-1, Grt-2, Grt-3). Grt-1 (Adr 73-88) exhibit compositional variations as oscillatory zoning. Grt-2 (Adr 93-100) is almost pure andradite, with smooth surface. Grt-3 (And 71-93) occur as halo surrounding earlier andradite, with broken surface. Incorporation of REE and U into all generations of andradite mainly follows coupled YAG-type substitution mechanism and the coupled substitution of [U4+]VIII + 2[Fe3+, Al3+]Ⅳ – [Ca2+] – 2[Si4+]Ⅳ in the dodecahedral position, respectively. Their associated intrusions, mineral assemblages and consistent positive Eu anomalies indicate an acidic, oxidizing and low salinity forming conditions. From core to rim, the contents of REE and HFSE are decreasing, and the REE patterns evolve from flatted, through LREE-enriched, HREE-depleted, to REE-depleted. The chemical composition and evolution of oscillatory zoned andradite suggest that the fluids in Chengmenshan deposit experienced the sequences of pore fluid-mixed, through magmatic-hydrothermal dominated, to meteoric water influx. In this process, the temperature, pH and fluid compositions varied. U contents are closely correlated with REE contents, especially LREE contents. The andradite samples yield Tera-Wasserburg lower intercept 206Pb/238U ages of 140.1 ± 2.6 Ma (MSWD = 1.8), representing the age of Cu-Au mineralization. These results indicate the evolutionary characteristics of hydrotheraml fluids and precisely date the Cu-Au skarn formation, which may serve as a useful indicator in the exploration of similar skarn deposits and point selection for U-Pb dating. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Shangkelan alkali-feldspar granite and granitic pegmatite constitute a continuous differentiation granite–pegmatite system. • The alkali-metal elemental variations are mainly controlled by Rayleigh crystal-melt fractional crystallization. • The F- and W-rich fluid exsolution and subsequent greisenization played an important role in the wolframite mineralization. The Shangkelan granite–pegmatite is known for its internal zonation and tungsten mineralization in the Chinese Altai. However, the genetic relationship between the granite and pegmatite and the W mineralization mechanism in Shangkelan remains unclear. Here we present monazite U–Pb ages and Nd isotopic composition, and whole-rock and muscovite chemical compositions of each zone of the stock, to address these issues. From bottom to top, the stock mainly consists of alkali-feldspar granite (AFG) and granitic pegmatite (GP). Monazite LA-ICP-MS U–Pb dating and Nd isotopic analyses reveal that the AFG and GP have identical ages and similar εNd(t) values, 189 ± 2 Ma and −0.79–+0.38 and 190 ± 1 Ma and −0.70–+0.01, respectively. Whole-rock geochemical results show that the stock is highly fractionated and has a differential trend characterized by increasing Rb, Cs, and Tl contents, decreasing W, Ba, and Sr contents, and Zr/Hf ratios from the AFG to GP. Both primary (magmatic) and secondary (hydrothermal) muscovites have been recognized in Shangkelan. From the AFG to GP, element concentrations and ratios of primary muscovite form well-defined differentiation trends marked by gradual increases in Rb, Cs, and Nb, and decreases in W, K/Rb, and Nb/Ta. Based on the gradational contacts in field, identical monazite ages, and similar Nd isotopic compositions, together with the differentiation trends of incompatible elements (such as Rb and Cs) in bulk-rock and primary muscovite and alkali metal Rayleigh fractionation modeling results, we consider that the AFG is parental to GP and they were produced by continuous fractional crystallization of a common magma source. Additionally, for the monazites Nd isotopes, their two-stage Nd model ages of 1034–939 Ma and slightly negative to positive εNd(t) values (−0.79–+0.38) indicate that the magma sources were mainly derived from the reworking of the Stenian–Tonian basement. Secondary muscovite precipitated from the fluids that exsolved from the parental AFG melt has high contents of F and W. Tungsten may be dissolved as H 3 WO 4 F2− in the fluids. The greisenization caused the destabilization of H 3 WO 4 F2− and eventually led to the precipitation of wolframite in Shangkelan. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Mazhala Au-Sb deposit in South Tibet was constrained at ca. 35 Ma. • Mazhala apatite belongs to fluorapatite having F contents of 2–4%. • Mazhala apatite is rich in MREE but depleted in LREE- and HREE. • Mazhala apatite have δ18O values in the range of 16-19‰. • The Mazhala Au-Sb deposit was mainly precipitated from metamorphic water. Due to lack of suitable datable minerals, timing of the Mazhala Au-Sb deposit in South Tibet remains unresolved. Also, previous geochemical studies suggest an ambiguous conclusion on the source of ore-forming fluid, with diverse viewpoints of magmatic water, mixed magmatic–meteoric water or mixed metamorphic-meteoric water, respectively. In this study, hydrothermal apatite U-Pb dating constrains the Mazhala Au-Sb deposits to have formed at ca. 35 Ma, consistent with the timing of Eocene leucogranite intrusions in South Tibet. The Mazhala Au-Sb mineralization occurred during the main collision stage to late collision stage in Eocene to Oligocene, and predates the Cuonadong Sn mineralization in South Tibet which occurred during the crustal extension stage in Miocene. An EPMA analysis shows the apatite belongs to fluorapatite that have F contents in the dominant range of 2–4%. The Mazhala apatite displays an overall MREE enrichment and LREE- and HREE depletion distribution pattern with positive Eu anomalies, and have δ18O values dominantly in the range of 16-19‰ with a mean δ18O‰ value of 17.74 ± 0.15‰ (2σ), which suggest a relatively homogenous chemical composition for the ore forming fluids with a relatively stable temperature regime. In combination with previous temperature estimates, the ore forming fluids are inferred to have a dominant δ18O fluid value of 13-16‰, which overlap with metamorphic water. The combined age and geochemical data suggest Eocene leucogranite intrusion induced metamorphic fluid circulation within Paleozoic-Mesozoic metamorphic sedimentary rocks around the study area, which prompted precipitation of fluorapatite together with Au-Sb bearing pyrite and arsenopyrite in the Mazhala Au-Sb deposit. This study puts an emphasis on the contribution of metamorphic water as the dominant ore-forming fluid origin in the Mazhala Au-Sb deposit. In contrast, the close spatial and temporal association of the Cuonadong Sn polymetallic mineralization with the Miocene leucogranite intrusion-induced hydrothermal activity in the Cuonadong dome demonstrates that their genetic links, as was also evidenced by C-H-O-S-Pb isotope data that point to a dominant contritution of Miocene leucogranite to ore-forming fluid and materials for the Cuonadong Sn polymetallic ore deposits. As such, from a perspective of ore-forming model in South Tibet it be seen that during the main collision stage to late collision stage ore-forming fluid and materials were mainly derived from metamorphic water, whereas during the crustal extension stage, ore-forming fluid and materials were dominantly sourced from magmatic water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three stages of W-Sn mineralization in the Xitian Ore Field have been identified. • Triassic skarn-type mineralization occurred in a relatively closed metallogenic system. • Jurassic quartz vein-type mineralization occurred in an open system with addition of meteoric water. • Deeply buried Early Cretaceous magmatic-hydrothermal deposits may exist in the Xitian Ore Field. • Evolution from skarn-type to vein-type mineralization was related to tectonic environment changing. The Nanling Metallogenic Belt is a major W-Sn province in South China containing numerous ore deposits formed during a complex history of magma emplacement and mineralization. The Xitian ore field in Hunan Province is a typical example of a late magmatic-metallogenic system. In this study, garnets from skarn-type ores in the Xitian ore field yield a U-Pb age of 231.7 ± 1.3 Ma (n = 33), whereas cassiterite grains from quartz vein-type ores give U-Pb ages of 158 to 154 Ma (n = 72) and 140.7 ± 3.3 Ma (n = 6), suggesting three stages of W-Sn mineralization (Late Triassic, Late Jurassic, and Early Cretaceous). In the Late Triassic skarn-type ores, the REE patterns of scheelite change from MREE-enriched to LREE-enriched with time, whereas the REE patterns of scheelite shift from MREE-enriched to MREE-depleted in the Late Jurassic quartz vein-type ores, indicating diverse metallogenic processes. Differences in the Y/Ho ratios and Sr-O isotope compositions of scheelite further confirm discrete metallogenic pathways for the Late Triassic skarn-type W ore and the Late Jurassic quartz vein-type ore, with fluid-rock interaction of the former dominated by magmatic-hydrothermal fluids whereas the latter was influenced by large amounts of meteoric water. A model emphasizing the evolution from skarn-type to vein-type metallogeny is proposed to account for the complex genesis of multistage W–Sn deposits related to the Xitian granite complex. More generally, this study demonstrates that in-situ LA-ICP(MC)-MS U-Pb dating and isotopic analysis of hydrothermal minerals are powerful tools to decipher the nature, timing, and evolution of multistage W-Sn metallogenic systems. [ABSTRACT FROM AUTHOR]