The early Precambrian tectonic evolution of the North China Craton has been debated for years. Here, we focus on the structural relationships between the ca. 2.5 Ga Wangjiazhuang granite and its host rocks in the Zanhuang Massif by integrating multiscale observations and methods, including field studies, electron backscatter diffraction fabric analysis, and host-rock geochronology, to evaluate the tectonic evolution of the Zanhuang Massif and its relationship to the North China Craton. At the pluton scale, foliations in both the marginal Wangjiazhuang granite and its host rocks are parallel to the boundary of the pluton. However, the internal foliation of the Wangjiazhuang granite strikes nearly east-west, approximately parallel to the regional foliation in the host rocks. At the outcrop scale, the host rocks near the granite are characterized by a shear sense of downward transport attributed to the emplacement of the granite, whereas those farther away exhibit a regional top-to-the-southeast shear sense. At the grain scale, the Wangjiazhuang granite exhibits both magmatic and subsolidus fabrics that are mutually parallel. Electron backscatter diffraction analysis shows that quartz in the Wangjiazhuang granite mainly underwent prism slip deformation corresponding to 500-600 degrees C, and plagioclase also experienced deformation at >550 degrees C, consistent with the medium- to high-temperature subsolidus deformation. The subsolidus fabric at the margin of the granite is more developed than at the core, while the magmatic fabric shows the opposite pattern. These relationships indicate that the granite foliation is partially coupled with the main foliation in the host rocks. The Wangjiazhuang granite is identified as a syn-tectonic intrusion. The structures at the margin of the Wangjiazhuang granite and its nearby host rocks were mainly controlled by the emplacement of the granite, while the internal fabrics of the granite were influenced by regional tectonic convergence. Maximum depositional ages obtained from zircon U-Pb dating of the host rocks, including quartzite and quartz-mica schist, are 2.53-2.52 Ga. Structural relationships between the Wangjiazhuang granite and its host rocks constrain the depositional age of the host rocks to between 2.53 Ga and 2.50 Ga. Structural and geochronological analyses of the Wangjiazhuang granite and its host rocks indicate that the Zanhuang Massif experienced northwest-southeast convergence at ca. 2.50 Ga, following the arc-continent collision between the Fuping terrane and the Eastern Block. Critically, second-order extension was potentially driven by slab rollback or break-off, facilitating the emplacement of syn-tectonic A-type granite. This study demonstrates the operation of a dynamic plate tectonic regime involving subduction, collision, and slab failure in the late Neoarchean North China Craton.

Li-Rb-Cs rare metal mineralization is closely linked to highly fractionated granites. However, the origin of Li-Rb-Cs rare metal mineralization during the shear-deformation remains unclear. The Gaoligong Shear Zone (GSZ) is situated along the eastern margin of Tibetan in southwestern China. It is a dextral strike-slip shear zone formed by the northward movement of the India Plate to relative to the Eurasia Plate during Oligocene-Miocene. Bulk mineral composition, together with EMPA and LA-ICP-MS data, reveal that Li-Rb-Cs-rich phlogopite occurs in Carboniferous metamorphic rocks of the GSZ. This phlogopite is enriched in F (4.29-5.06 wt%), Li (1281-1849 ppm), Rb (2550-3242 ppm), and Cs (386-1575 ppm), but depleted in Be (<1 ppm). In contrast, scapolite (marialite) intergrown with the Li-Rb-Cs-rich phlogopites is enriched in Be (31.31-91.34 ppm), and Ga (38.92-48.83 ppm), but poor in Li (1.86-18.71 ppm). Two phlogopite samples yield (ArAr)-Ar-40-Ar-39 plateau ages of 15.64 +/- 0.36 Ma, and 14.44 +/- 0.23 Ma, indicating Miocene formation. These ages coincide with major shearing and regional metamorphism in the Gaoligong area. This suggests the formation of Li-Rb-Cs-rich phlogopite may have been related to intense shearing and intracrustal melting. Magma-derived metasomatic hydrothermal fluids may have contributed to the formation of the Li-Rb-Cs-rich phlogopite and the Be-rich scapolite. The study suggests that the Li-Rb-Cs rare metal mineralization can form during the shear deformation and that F-rich phlogopite is a promising indicator for rare-metal exploration in the shear deformation zone.

The southwestern Hunan gold metallogenic belt is one of the most significant gold mineralization belts in the Xuefengshan region of South China, hosting numerous gold deposits. This study investigates the occurrence, transport, and precipitation mechanisms of gold in the Jinkeng (JK) and Huanggou (HG) deposits, southwestern Hunan, within the Jiangnan orogenic belt. Combined petrographic, microanalytical, and geochemical data indicate that invisible gold predominantly exists as lattice-bound Au+ within pyrite and arsenopyrite, while visible gold occurs mainly along micro-fractures or as coarse-grained grains precipitated directly from hydrothermal fluids. Gold transport was primarily controlled by Au(HS)2 - and AuH3SiO4 complexes under lowtemperature (130-266 degrees C), low-salinity, and reducing conditions. Sulfide geochemistry reflects the behavior of dissolved Au species, whereas fluid-rock interactions, including reduction and desulfidation processes, triggered gold precipitation. High Sb concentrations in arsenopyrite suggest that Sb-rich fluids inhibited Au incorporation into sulfides, highlighting a genetic link between Au and Sb mineralization. The Co/Ni ratios of pyrite, coupled with H-O isotopic compositions of quartz (delta Dfluid: -76.4 to -50.6%o; delta 18Ofluid: +1.0 to +3.1%o), indicate that the ore-forming fluids were primarily derived from metamorphic dehydration reactions during regional tectonothermal events, accompanied by an influx of meteoric water. The deposits (mainly JK) were modified by Yanshanian magmatic-hydrothermal activity. These results provide new insights into gold transport, deposition, and the fluid evolution in orogenic gold systems of the Jiangnan belt.

Recent gold exploration in the Jiangnan orogenic belt, South China, has yielded significant progress, particularly within regions characterized by complex tectonic evolution and magmatic-hydrothermal activity. Despite these advancements, the sources of ore-forming fluids and the genesis of gold deposits in southwestern Hunan, western Jiangnan orogen, remain poorly understood. To address these gaps, this study integrates detailed fieldwork, petrographic investigation, and trace element geochemistry of gold-bearing pyrite and arsenopyrite, alongside hydrogen and oxygen (H-O) isotopic compositions of quartz, from four representative gold deposits: Taojinchong, Yangwantuan, Mobin and Xinhuang Mibei. Pyrite from these deposits exhibits a range of elemental concentrations: very low to low (< 0.1-10 ppm) for Zn, Mo, Bi, Co, Cu, Sb, Au, Ni and Pb; moderate concentrations (10 to 1,000 ppm) for Ge, Ni, Pb, Co, Cu, Sb and Au; and elevated concentrations (> 1,000 ppm) for As. Arsenopyrite crystals show very low to low concentrations (< 0.1-10 ppm) of elements such as Cu, Zn, Ag, Co, Mo, Te, Bi, Ni, Au and Pb; intermediate concentrations (10 to 1,000 ppm) of Ge, Ni, Au, Pb, Co, Te; and extremely high concentrations (> 1,000 ppm) of Sb. The delta Dfluid values vary from-72.3 %o to-48.9 %o, while the delta 18Ofluid values range from 0.3 %o to 4.6 %o. Gold occurs in both visible and invisible forms, with the latter predominantly existing as lattice-bound gold in pyrite and arsenopyrite crystals. The findings revealed that gold transport occurred primarily as complexes (e.g., Au(HS)2-and AuH3SiO4) within weakly acidic, low-temperature, and reducing metamorphic-hydrothermal fluids. We propose that metamorphic-hydrothermal fluids were the primary source of ore-forming fluids during the mineralization process, accompanied by late-stage influx of meteoric water. The pronounced enrichment of Sb in these mineralizing fluids highlights a potential genetic association between Au and Au-Sb deposits in the Jiangnan Orogenic Belt, offering new exploration targets in analogous collisional orogens.

Rare metal deposits are generally associated with highly fractionated granites with unique geochemical signatures and the mineralization is controlled by composition of magmas, degree of magma fractionation, and magmatic-hydrothermal processes. The Ganfang rare metal deposit, located in Jiangxi Province, south China, is hosted within a strongly peraluminous, P and F-rich S-type rare-metal granite pluton (the Ganfang composite granite pluton) of Early Cretaceous age in the Jiuling Neoproterozoic granitic batholith. The pluton comprises two-mica monzogranite, topaz-bearing muscovite-albite granite, and felsite (locally aplitic) dikes. The topaz-bearing muscovite-albite granite is highly enriched in Li, Ta, Sn, Nb, Be, Rb, and Cs, while the felsite displays ultra-high enrichment of P, Li, Cs, Rb, Be, W, Sn, Nb, and Ta. The cassiterite U-Pb (137-140 Ma), monazite U-Pb (similar to 140 Ma), and muscovite Ar-Ar (140-142 Ma) ages indicate a coeval magmatic association for the pluton. Nd isotopic compositions indicate magmatic origination in the Late Paleoproterozoic metasedimentary basement. However, the significant differences in contents of SiO2, Al2O3, Li2O, P2O5, Rb2O, Cs2O, and F among these three components suggest unlikely a single parental magma source. The columbite minerals in the topaz-bearing muscovite-albite granite show complex replacement textures and unique chemical composition, suggesting involvement of locally Ta-saturated magma and melt-fluid metasomatism during the magma evolution process. The felsite shows high F (up to 1 wt%), P2O5 (up to 1.2 wt%), and Li2O (up to 1.5 wt%), indicating that the magma sequestered a large quantity of incompatible elements and ascended rapidly through the melt column to its emplacement level. In summary, enrichment of source magmas with rare metals, extreme fractionation, and melt-fluid metasomatism are the key factors in controlling genesis of the Ganfang Li-Rb-Cs-Be-Ta-Sn deposit.

The western Yunnan region is located in the southeastern part of the Tibetan Plateau, and its geological evolution in history is a microcosm of the Tethys tectonic belt. A large-scale Cu, Pb, Zn and other non-ferrous metal deposits occur in western Yunnan. However, the potential of rare metal mineralization has been a scientific issue to geologists in the past decades. In the process of carrying out the project "Assessment of the Current Status and Prospects of Rare Metal Resources" of "Comprehensive Study of the Second Scientific Expedition of Tibetan Plateau", the paper collected, analyzed, and organized existing geological exploration data, geochronological data, geochemical and isotopic data based on previous research. Through the investigation and research of typical rare metal deposits (occurrences), it reveals the metallogenic and resource prospects of rare metals in western Yunnan. Rare metal deposits in western Yunnan are mainly distributed in banded and locally concentrated along the Nujiang River Fault and Lancang River Fault. The rare metal mineralization mainly includes granite, pegmatite, skarn, greisen, tourmaline-quartz vein, sulfide-quartz vein, phlogopite vein, weathering, as well as coal-host and hot-spring-host type. Some granite and pegmatite rare metal deposits host precious jade resources (such as tourmaline, aquamarine, etc.). These rare metal deposits were mainly formed in six periods: Triassic (240 similar to 220Ma), Early Cretaceous (124 similar to 120Ma), Late Cretaceous (80 similar to 70Ma), Paleocene-Eocene (65 similar to 50Ma), Oligocene (33 similar to 30Ma), and Miocene (25 similar to 12Ma). They are related to the collision environment after the closure of the Paleo-Tethys Ocean in the Triassic, the subduction and collision of the New-Tethys Ocean, and the large-scale shear strike slip after the collision between India and Eurasia, respectively. Li-Be-Rb-Cs rare metal deposits were mainly formed in the Eocene-Oligocene and Miocene, which related to contemporaneous shear strike-slip deformation-metamorphism. It shows that rare metal mineralization in western Yunnan, has the characteristic of regional and temporal controlling, and the characteristics of being rich in F or B, or rich in F and rich in B, and are closely related to granites with high differentiation in different periods. Indicator minerals such as cassiterite, tourmaline, and mica can trace the mineralization process of rare metals and the differences in the composition of ore-forming elements. This paper suggests that it has good potential for rare metal mineralization in western Yunnan, the granite and pegmatite rare-metal deposits as the main resources for next exploration. In the future, the exploration of Li-Rb-Cs will mainly focus on the Nujiang metallogenic belt, with granite-type rare metal deposit and weathering-type rare metal deposits in the Tengchong-Lianghe area, pegmatite and hydrothermal vein being the main resource in the Gaoligong area. The exploration target for Be mineralization mainly focuses on the Gaoligong area and Tengchong-Lianghe area, Chongshan and Ximeng regions should also pay more attention. The exploration of Nb-Ta and Zr-Hf should pay much for their associated main mineralization species. Tin mineralization should be considered more in depth and peripheral in the current exploration project.

To assess the effect of mining activity on heavy metal pollution and associated health risks in tin mining regions, water and soil sampling was conducted near a tin mining site in Hunan Province. The content and distribution of heavy metals were determined. Pollution, ecological risks, and potential health hazards were evaluated using the ground accumulation index, potential ecological risk index, and health risk assessment models, respectively. The results indicated elevated levels of heavy metals in water and soil samples compared to acceptable background values. Ground accumulation index assessment revealed extreme pollution of soil with As and Cd and moderate pollution with Cu, Pb, and Zn. Cr and Hg were categorized as non-pollutants. Water samples exhibited extreme pollution levels of Hg, Cr, Cd, and As;moderate pollution levels of Pb; and moderate to high pollution levels of Cu and Zn. The tin mining area demonstrated a significantly high level of potential ecological risk, where As and Cd were the primary risk elements in soil, whereas Cr, Cd, and As contributed predominantly to water ecological risk. The human health risk assessment highlighted As, Cd, Cr, Hg, Pb, and Cu in water and As and Pb in soil as the principal non-carcinogenic factors. The primary carcinogenic factors were As, Cr, and Cd in water and As in soil, with As posing the greatest risk for non-carcinogenic and carcinogenic effects. Furthermore, oral intake was the primary exposure route, with children being particularly vulnerable to the adverse effects of heavy metal pollution.

Lithium (Li), as a strategic critical metal, plays a pivotal role in the emerging energy landscape, particularly in the context of Li-ion batteries driving the new energy economy. Recently, Li-rich strata (with Li2O > 0.3 wt%) have been discovered in the Mesoproterozoic Wumishan Formation in Hebei Province, North China, suggesting a prospective Li reservoir. This study investigates these Li-rich strata using geochemical and in-situ micro- analytical techniques to explore the occurrence of Li and the formation mechanism of Li-host minerals, aiming for a comprehensive understanding of the supernormal enrichment of Li. The Li-rich samples are predominantly composed of dolomite and quartz, followed by clay minerals such as illite, interstratified illite-smectite (I/S), and chlorite, with minor amounts of K-feldspar, albite, biotite, calcite, baryte, fluorite and fluorapatite. In-situ analysis and 7 Li NMR spectroscopy reveal that Li predominantly occupies the octahedral sites within the structures of authigenic illite and I/S, while its absence in clastic illite, clastic chlorite, unaltered K-feldspar, and dolomite. The presence of veined minerals (e.g., fluorite, baryte, and calcite) and a strong positive correlation between Li and F imply that post-depositional hydrothermal fluids have significantly contributed to the formation of Li-host minerals. The paragenesis of these minerals suggests that Li-bearing illite has formed through the hydrothermal alteration of K-feldspar. These Li-bearing illites subsequently transformed into Li-bearing I/S, consisting of illite-rich I/S and smectite-rich I/S, under continuous hydrothermal alteration. Lithium could have been leached from the surrounding carbonate rock and tuff through water-rock interaction and subsequently enriched by post-depositional hydrothermal fluids in specific regions, leading to mineralization. These findings provide valuable insights for targeting exploration of this promising Li resource.

Volcanic-hosted beryllium deposit is an important type of beryllium resource, it provides over 80% of global beryllium resources annually. Therefore, the exploration and discovery of this type is crucial to improve the safe supply capacity of beryllium resources in China. On the basis of preliminary field geological investigation, analysis and testing, and geological profile measurement, three volcanic-hosted beryllium occurrences, such as Shangwan, Songdong and Rongjingba, were discovered in the terrestrial volcanic rock area of Mikengshan, Jiangxi Province, South China. According to the host rock, it can be divided into two types of mineralization: (1) topaz-bearing sulfide quartz vein in pyroclastic lava, and (2) altered rock type in the fractured zone in the tuff. Topaz-bearing sulfide quartz vein occur as large veins, veinlets, stockwork, and/or massive. It is mainly composed of topaz, quartz, muscovite, biotite, sphalerite, galena, cassiterite, wolframite, molybdenite, phenakite and bertrandite. At present, more than 20 topaz-bearing sulfide quartz vein have been discovered, with Be content range from 106×10-6 to 850×10-6. The altered rock type is mainly distributed along the fracture zone in the tuff, and the ore is mainly composed of quartz, fluorite, chlorite, sphalerite, galena, cassiterite, beryl, phenakite and bertrandite. Four altered fracture zones have been found in the tuff, which with Be content range from 40×10-6 to 2790×10-6. The Be concentration in altered fracture zone increased with the degree of chloritization alteration. The hydrothermal alterations related to beryllium mineralization are mainly composed of topazization, muscovitization, fluoritization, chloritization, and carbonatization. This paper obtains a zircon SHRIMP U-Pb age of 136.4±1.8Ma for porphyroclastic lava, two cassiterite U-Pb ages of 137.4±1.9Ma from topaz-bearing sulfide quartz vein in porphyroclastic lava and 134.7±4.8Ma from altered rock in the fractured zone in the tuff type, respectively. These two events formed almost simultaneously within the error range, which suggests the beryllium mineralization is close to or slightly later than the crystalline tuff deposition and porphyroclastic lava erupted in the region, and is related to volcanic magmatic activity. The discovery of volcanic-hosted beryllium occurrences not only provides a clue to search for this type of deposit in volcanic-sedimentary basins in the region, but also provides reference for the exploration for volcanic-hosted beryllium deposits in areas where porphyry and sub-volcanic tin deposits are developed.

Beryllium is a strategically critical metal, and its accurate in situ analysis in beryllium minerals is challenging in the field of earth science. High spatial resolution is also a difficult point in the analysis. A new analysis approach for the accurate and precise determination of beryllium contents in beryl using an ablation spot size of 13 mu m by LA-ICP-MS was first achieved in this study. The control variables were used to optimise the instrument conditions and determine the laser ablation parameters suitable for determining beryl under an ablation spot size of 13 mu m. The energy density was set at 5.5 J/cm 2 with a repetition rate of 4 Hz, and the ablation time was 50 s. A new concept, the Relative Fractionation Index ( RFI ), was proposed to measure fractionation and matrix effects. Two potential beryl reference substances (B4-2 and Brl-3) were also assessed by determining their homogeneity to further improve the measurement accuracy. Other common beryllium minerals, including phenakite, chrysoberyl, and herderite, were identified in this study. By comparing the RFI values of different minerals and reference materials, appropriate reference materials and determination conditions were selected, and ideal analysis results were obtained. Therefore, the accurate and precise determination of beryllium contents in common beryllium minerals was achieved using an ablation spot size of 13 mu m by LA-ICP-MS.

The Mibei gold deposit, located in the southwestern part of the Xuefengshan uplift zone, the middle section of the Jiangnan orogenic belt in southern China, has estimated gold resources of approximately seven tons. This deposit is primarily a quartz vein-type gold deposit, with ore bodies occurring mainly within Neoproterozoic metasediments. The main metallic minerals in the ore are pyrite, chalcopyrite, and arsenopyrite. In this study, the petrography and microthermometry of ore-forming fluid inclusions, oxygen isotopes of gold-bearing quartz, and sulfur isotopes of gold-bearing sulfides and arsenopyrite were analyzed. Three types of fluid inclusions were identified: type Ia three-phase inclusions comprising vapor and two phases of liquids (VCO2 + LCO2 + LH2O), type Ib two-phase liquids (LCO2 + LH2O), type II two-phase vapor-rich inclusions (V/V + L > 50%), and type III pure liquid inclusions. Type I inclusions were heated uniformly to the liquid phase, type II inclusions were heated uniformly to the gas phase, and type III inclusions were heated without change. In general, the temperature range of homogenization to liquid phase of fluid inclusions in the Mibei gold deposit is 204–227°C. The salinity of the inclusion ranges from 4.6 to 12.2 wt% NaCl equiv. The δ18OSMOW of gold-bearing quartz varies from 16.9‰ to 17.5‰. The δ18OH2O of gold-bearing quartz are varied from 6.5‰ to 7.5‰. The δ34S values of gold-bearing pyrite range from 1.7‰ to 6.8‰. The δ34S values of gold-bearing arsenopyrite range from 5.6‰ to 5.9‰. The δ34S values of pyrite from wall rocks slate range from 6.4‰ to 11.6‰. This evidence implies that the ore-forming fluids of the Mibei gold deposit originated from magmatic-hydrothermal processes, mixing with minor S from the surrounding metasediments. Combined with the evolution of the Jiangnan orogenic belt, due to the magmatic and tectonic activities of the Xuefengshan uplift during the Caledonian period, the fault seal mechanism controlled the ore-forming process. Overall, the Mibei gold deposit is more akin to a magmatic-hydrothermal gold deposit.

Pegmatite rare metal deposits are vital sources of rare metals. However, their metallogenic mechanism remains controversial. Numerous pegmatites have been discovered in the Gaoligong High-Grade Metamorphic Belt, southeastern margin of the Tibetan Plateau, southwestern China. These pegmatites can be categorized into rare metal-bearing pegmatites, such as albite pegmatite and perthite-albite pegmatite, and non-rare metal-bearing pegmatites, including orthoclase-albite pegmatite and biotite pegmatite. The rare metal minerals columbite, tantalite, cassiterite, and beryl intergrown with hydrothermal muscovite, topaz, and apatite are observed in the rare metal-bearing pegmatites. In the rare metal-bearing pegmatites, magmatic muscovite that is enriched in rare metals exhibits significantly higher Rb2O and Cs2O levels, lower MgO and FeO concentrations, and lower K/Rb ratios than magmatic muscovite found in non-rare metal-bearing pegmatites, which show higher MgO, FeO, and K/Rb values but lower Rb2O and Cs2O contents. Hydrothermal muscovite in rare metal-bearing pegmatites has distinctly higher F, Li2O, Rb2O, and Cs2O values than its magmatic counterpart. Additionally, orthoclase and albite from rare metalbearing pegmatites have relatively high levels of P2O5. The decreasing K/Rb values from non-rare metalbearing to rare metal-bearing pegmatites indicate an increase in the degree of pegmatite evolution. The increase in F, Li2O, Rb2O, and Cs2O concentrations in muscovite from the magmatic to hydrothermal stages in rare metalbearing pegmatites suggests the involvement of F-, Li-, Rb-, and Cs-rich fluids in rare metal enrichment. Cassiterite U-Pb dating of rare metal-bearing albite pegmatite and perthite-albite pegmatite yields ages of approximately 14.79 +/- 0.76 Ma and 16.81 +/- 0.36 Ma, respectively, indicating that rare metal mineralization occurred during the Miocene. The rare metal mineralization in the Gaoligong High-Grade Metamorphic Belt (GHMB) is related to movements along strike-slip faults following the collision between the Indian and Eurasian plates. The differentiation of these magmas and the associated hydrothermal activity played a crucial role in rare metal mineralization, and hydrothermal processes were particularly instrumental in the GHMB.

The southwestern Hunan province (SHP) is an important gold mineralization province in the Xuefengshan Uplift (South China) and is represented by quartz vein-type gold deposits. Gold deposits and occurrences in this district are geologically similar and can be regarded as specific manifestations of the same extensive gold mineralization in different spatial locations. In this study, the metal sources and mineralization processes of gold mineralization in the SHP have been discussed based on zircon geochronology and geochemistry from six gold deposits. The zircon age distribution is similar in most of the samples, mainly plotted in a narrow range: 900 to 600 Ma, with the major peak around 800 +/- 50 Ma. It overlaps with the detrital zircon age distributions of the Lengjiaxi Group, Banxi Group, and Jiangkou Formation. The trace elements and Lu-Hf compositions of these zircons further prove an original relationship between the gold mineralization and strata. In addition, the Indosinian magmatic activities might also be potential sources for the zircons in these deposits, as 7 of 349 analyzed zircons with ages of approximately similar to 240 Ma were observed. The differences in trace, as well as rare elements, have been widely seen in zircons suggesting that the gold mineralization has been modified to different degrees by post-mineralization hydrothermal fluids which are considered as related to Indosinian magmatic activities. Combined with the geological characteristics of gold mineralization, the gold deposits in the SHP are typical orogenic gold deposits forming during the Caledonian movement and modified by Indosinian magmatic-hydrothermal fluids. The highlights of this study are using zircon geochronology and geochemistry to clarify the genesis of gold mineralization in the SHP and providing a new method to understand the genesis of similar vein-type gold mineralization worldwide.

The Tongshanyuan copper polymetallic deposit is located between the two faults of Jiangshan-Shaoxing and Lishui-Yuyao, Lishui-Ningbo Uplift Zone belong to southeastern Zhejiang Fold Belt of the Cathaysia Fold System. The mineralization of this deposit is mainly controlled by northeast-trending and northwest-trending compression faults, and the host rock is the Zhantou Formation of the Proterozoic Badu Group. The mineralization is mainly divided into fractured-zone altered rock type and quartz vein type, respectively. On the basis of systematic geological investigation and the chemical analysis , we found significant enrichment of beryllium in the fractured-zone altered rock type ores, with Be content ranging from 15.5x10(-6) to 147x10(-6) . Based on the EPMA and Laser Raman Spectroscopy analysis, the beryllium mineral is mainly composed of bertrandite. The fluoritization and carbonation is closely related to bertrandite precipitation, which can be classified as a new type of beryllium mineralization-metamorphic-modified beryllium ores. In this type of deposit, Be may mainly migrated in the form of (BeF (4))(2-) and [Be(CO3)(2)](2-) complexes in the ore-forming fluid . When the ore-forming fluid encounters Ca-bearing minerals such as andradite, F- or CO32- in the hydrothermal solution combines with calcium iron to form fluorite or calcite, causing (BeF4)(2-) and [Be(CO3)(2)] (2-) complexes to precipitate in the form of bertrandite. The discovery of beryllium mineralization at the Tongshanyuan copper polymetallic deposit provides a good example for searching for this new beryllium resources in the area. The paper also suggests much more attention should also be paid to the enrichment and mineralization of other key metals such as Cd, Co, and In in the area when searching for this new type beryllium resources.

The Lancangjiang tin belt is located on the eastern margin of the Tibetan Plateau, which is in the northern part of the Southeast Asian tin belt that contains Sn, W, and base metal ore deposits. Tourmaline alteration and high B contents are typical features of the magmatic-hydrothermal systems in the Lancangjiang tin belt. Our new data for tourmaline intergrown with cassiterite reveal complex geochemical features that provide important insights into the origins of ore-forming fluids in this B-rich tin belt. Most of the tourmaline in the Sn deposits and metamorphic rocks belongs to the alkali-group dravite series, except for some that is part of the X-vacant group. The tourmaline compositions differ among the ore districts, but all exhibit Fe-poor (0.61-1.08 apfu) and Mg-rich (1.43-2.06 apfu) compositions, with Fe/(Fe + Mg) = 0.18-0.46. Most trace elements in the tourmaline occur at low contents (<50 ppm), including the large-ion lithophile elements (e.g., Cs and Ba) and high-field-strength elements (e.g., Nb, Ta, Hf, and Th). However, some trace elements (e.g., Zn, Sr, and V) and Sn have high contents (up to several hundreds or thousands of ppm). The delta B-11 values of tourmaline from the Sn deposits range from -14.7 parts per thousand to -11.3 parts per thousand, except for those in the Man Makhsan Sn deposit, which range from -12.0 parts per thousand to -8.1 parts per thousand. The delta B-11 values (-14.7 parts per thousand to -8.1 parts per thousand) and the positive correlation between Sn contents and Nb/Ta, Al/Ga, and K/Cs ratios in the ore-related tourmaline indicate that the exsolved ore-forming fluids were derived from highly fractionated S - type granitic magmas. The fluids were mainly B-, Sn-, and Al-enriched. The low Fe/(Mg + Fe) ratios, high oxygen fugacity, and Al saturation were favorable for cassiterite precipitation, and are proxies for the ore-forming potential of large-scale Sn deposits.

Devonian magmatism is one of the most important tectonothermal events in the Central Asian Orogenic Belt (CAOB). However, little is known regarding the petrogenesis and geodynamic setting of the widely distributed Devonian granitoids in the eastern Southern Beishan Orogenic Belt (SBOB). Early-Devonian granitic magmatism has been recognized from the Luotuoquan area, and the granites were emplaced between 404.9 Ma and 399.4 Ma according to LA-ICPMS zircon U–Pb dating. Geochemically, the granites exhibit high SiO2 and Al2O3 contents and are enriched in light rare earth elements as well as Rb, Th, Nd, Zr, and Hf, while being depleted in heavy rare earth elements and Ba, U, Sr, and Ti, with distinct rare earth element fractionation and pronounced negative Eu anomalies. According to the comprehensive analysis, they closely resemble the features typically associated with A-type granites. The zircons εHf(t) values are within the range of +0.90–+5.19 (averaged 3.23) for the monzogranite and syenogranite, whereas their TDM2 values fall between 1.05 and 1.34 Ga, suggesting that the magma source of the monzogranite–syenogranite originated from the partial melting of the Mesoproterozoic crust dominated by metagreywackes. Furthermore, the monzogranite and syenogranite exhibit high temperatures (average 782 °C), thin crustal thickness (average 30 km), and A-type characteristics, suggesting their formation in post-collision extensional settings. We propose the closure of the Beishan Ocean occurred before the early Devonian, followed by a transition in the Southern Beishan Orogenic Belt from a compressional to an extensional setting.

Zuun Mod is a porphyry-type Mo-Cu deposit located in the Edren terrane in Southwest Mongolia. The deposit has estimated resources of 218 Mt with an average Mo grade of 0.057% and Cu grade of 0.069%, and significant amounts of Re. The deposit is characterized by multiple pulses of magmatism and exsolution of magmatic ore fluids and associated alteration and mineralization. The timing of these events and the tectonic environment were unconstrained, and the deposit's origin remains controversial. Based on drill core and field examinations, four lithological units of the Bayanbulag intrusive complex are identified in the deposit area including quartz syenite, quartz monzonite, granodiorite, and granite. The majority of Mo mineralization at Zuun Mod occurs in sheeted and stockwork quartz veins that crosscut units of the Bayanbulag complex as well as disseminations within altered granitoids wherein the mineralized quartz veins occur with potassic and phyllic alteration selvages. Zircon U-Pb age dating for quartz monzonite and granodiorite defined the timing of magmatic events at 305.3 +/- 3.6 Ma and 301.8 +/- 2.7 Ma, respectively. Molybdenite Re-Os geochronology on grains from a quartz vein with potassic alteration selvage determined the age of Mo mineralization at 297 +/- 4.8 Ma. Lithogeochemical data of intrusive units suggest the granitoid rocks show calc-alkaline to high-K calc-alkaline, Itype, and metaluminous to slightly peraluminous affinities that formed in a post-collisional setting and were likely sourced from subduction-modified lithosphere. Lithogeochemical signatures and the tectonic environment classify Zuun Mod into neither Climax nor Endako-types, but as a Mo-rich porphyry Cu deposit.

As the mostly studied region of granite in China, Nanling Range in South China is extremely attractive for its close relationship of granite with mieralizations of W, Sn, Nb, Ta, Zr, Hf, Cu, Mo, Pb, Zn, Bi, Sb, U, Li, Be, REE, etc. It was generally thought that the above mineralizations were related to the highly fractionation of granitic magma, although the fractionation mechanism was not well understood. After summarizing the various characteristics from field investigation, and combining those indoors mineralogical and geochemical observations, it was suggested that the Mesozoic Yanshanian granites displayed a long-term and even continuous separation of crystal and residual melt within a magma chamber. The coarse-grained porphyritic granite is interpreted as the early cumulate crystallized during magma evolution, whereas the fine-grained granite as the residual high-silica melt after crystal fractionation. It was proposed that the above crystal-melt separation was controlled by two factors. One is the continuous input of mafic or new set of magma from below, which mobilized the mostly crystallized mush and triggered upward movement of the intergranular and metal-rich melt. Another is the marginal pegmatite (stockscheider) cover that prevented the lost of volatiles and maintained a sufficient fractional crystallization of magma within a close chamber. All these features make the Nanling granite much different from those of the Himalayan leucogranite that was similarly fractionated, but was formed by magma movement along a large scale of ductile detachment fault. Therefore, the Nanling Range granite and Himalayan leucogranite can be classified into thermal- and structural-driven end-members, respectively, in terms of highly fractionation mechanism of granitic magma. It is expected that an overall examination and evaluation should be conducted in the future to those late stage of highly fractionated granites, in order to meet the increasing demand for critical mineral resources. Especially, by deciphering the lithological sequence, mineralogical variation and evolution, metal enrichment and magma storage of the zinnwaldite-bearing granite and related greisen, a new step could be made up for the studies of the Nanling granite and its connection to the various mineralizations.

Helvine-group minerals have characteristic chemical compositions and textures and occur in different environments within magmatic–hydrothermal deposits. However, their origin is still unclear. There are several quartz-vein beryllium deposits with different element assemblages existing in southeastern China; these include the Dawan Be-Mo, Qidushan Be-Zn-Sn, and Taoxikeng Be-W deposits. We present the chemical composition of helvine-group minerals analyzed by electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry, in addition to zircon sensitive high-mass-resolution ion microprobe U-Pb and cassiterite laser ablation inductively coupled plasma mass spectrometry U-Pb ages. The zircon and cassiterite U-Pb data indicate that the Qidushan deposit formed during the Late Cretaceous (127–132 Ma). The electron probe microanalysis data show that the helvine-group minerals from the three deposits are helvine and/or danalite. A wide variety of different trace elements display high concentrations in the different deposits [e.g., helvine-group minerals from the Dawan deposit are rich in Li, B, Sc, V, Ga, Y, Sn, Cs, Th, and U; those from the Qidushan deposit are rich in Sc, Cd, and Sn; whereas those from the Taoxikeng deposit are rich in Y, Cd, Sn, Ta, and total rare-earth elements (ΣREE). The material analyzed from the Dawan deposit has the highest concentrations of Li (28.03–134.96 ppm), Sn (126.01–709.24 ppm), Sc (108.10–287.64 ppm), Cs (0–37.24 ppm), Th (4.78–112.63 ppm), and U (0.79–4.13 ppm). The material analyzed from the Taoxikeng deposit has the highest concentrations of Y (594.95–899.95 ppm), Cd (22.63–25.21 ppm), Ta (0.41–0.86 ppm), and ΣREE (281.69–451.79 ppm). However, those from the Qidushan deposit have the lowest concentrations of Y (10.21–37.70 ppm), Sn (0–26.88 ppm), U (0–19.06 ppm), Eu (0–0.14 ppm), and Cs (being below the detection limit). All of them are rich in heavy REEs but poor in light REEs, with distinctive REE patterns. Our results reveal that both crystallographic substitution and fluid composition control the enrichment of trace elements in helvine-group minerals. The textures and trace element compositions of helvine-group minerals can represent various parageneses and ore-forming fluid compositions. We propose that the δEu values and (La/Yb)N ratios can be used as markers to discriminate the genesis of helvine-group mineral precipitated from different environments based on the chemical compositions and the origin of ore-forming fluids.

铍、铯、铀等关键金属是支撑高新技术产业与尖端国防科技发展的战略性金属资源,其矿床的成因机制研究一直备受各国学者关注.研究发现,在一些关键金属矿床中均发育有蛋白石矿物,且蛋白石的形成与Be、Cs、U等金属元素的富集密切相关.这些关键金属的富集机制与蛋白石的成因、多相转化以及蛋白石中的微生物作用息息相关,这种关系主要表现在:(1)蛋白石成因与结晶相转化机制控制着关键金属元素的赋存形式、迁移机制与沉淀机制;(2)含铀蛋白石的年代学与硅氧同位素可以示踪关键金属成矿时代与沉淀的物理化学环境;(3)蛋白石中的微生物群落可以为关键金属元素的富集提供合适的氧化还原环境.蛋白石的矿物学、地球化学及其中的微生物成矿作用可以厘定关键金属矿床的成矿时代,示踪关键金属矿床的成矿物质来源,探讨关键金属矿床的成因机制.未来关键金属矿床中蛋白石的研究可以为低温环境下关键金属的富集成矿提供重要的科学依据.