The Xinjiang (China) to Central Asia region is located north of the Karakum-Tarim Craton and belongs to the Paleo-Asian Ocean tectonic domain, one of the world's three major tectonic domains. Distinguished by its unique geographical setting, this region is rich in mineral resources such as lead, zinc, copper, gold, rare earth, and lithium, and has become an important area for China's international mining cooperation in recent years. Guided by the "multi-island arc-basin system" tectonic model, this paper systematically summarizes the trmporal-spatial distribution, metallogenic setting and deposit types of lead-zinc deposits in the Xinjiang (China) to Central Asia region on the basis of tectonic unit division and carries out the division of three-level metallogenic units. A total of 2 metallogenic provinces are distinguished: Altai(-Xing’an Mongolia) and Kazakhstan-Tianshan; 4 metallogenic belts are Altai, Taerbahatai-West Junggar, Moint-Balkhash-Middle Tianshan and TurgayTalas; and 6 metallogenic subbelts are South Altai, Saryzhal-Zharma, Karasor-Moint-Yili, Bayan Uul- Zheirtau-Middle Tianshan, Karatau and Bukantau-Kyrgyz Mountain. Building on previous research, this paper further analyzes the metallogenic characteristics and typical deposits of each subbelt and discusses regional lead-zinc mineralization in combination with the tectonic evolution of the Paleo-Asian Ocean, aiming to provide a useful references for the comparative study and exploration of lead-zinc deposits in Xinjiang and adjacent overseas areas.

The study of metamorphism plays an important role in deciphering the composition and evolution of the deep crust, restoring the thermal evolution history of the crust, and guiding the prospecting. Both ancient continental blocks and Phanerozoic orogenic belts in northwest China are the key areas for the study of metamorphism in China. This paper reviews ultra-high pressure (UHP) metamorphism, ultra-high temperature (UHT) metamorphism, crustal anatexis, fluid activity in subduction zone and metamorphic mineral prospecting in northwest China in the past decade. In terms of UHP metamorphism, based on the new discoveries of evidences of UHP metamorphism represented by coesite, the fact of deep subduction of rocks has been further strengthened for previously established UHP metamorphic belts, and the East Kunlun UHP metamorphic belt was firstly established. In terms of UHT metamorphism, progresses in P–T paths, metamorphic ages and genesis of UHT metamorphism have been achieved in the Altai and Altyn orogen, and new outcrops of UHT metamorphic rocks have been identified in the East Kunlun, Qinling orogens and western Qaidam. The study of partial melting has been the focus of the study of orogenic metamorphism in the past decade, mainly including the products of partial melting, the tectonic setting and mechanism of melting. Studies on fluid activities in subduction zones focus on fluid identification and composition characterization, which provide a basis for further study of mass transfer in subduction zones. New discoveries of metamorphic ore deposits, represented by rutile and crystalline graphite, have been made.

The southern margin of the Central Asian Orogenic Belt (CAOB) represents one of the world’s most important provinces of amazonite-bearing granites and associated rare-metal deposits. However, the genesis and coloration mechanism of amazonite remain insufficiently constrained, which limits a deeper understanding of the petrogenesis of amazonite granites and the related rare-metal mineralization (e.g., Rb and Cs). In this study, amazonite samples were collected from five representative amazonite granite–type rare-metal deposits along the southern CAOB, namely Zhangbaoshan, Jiangjunshan, Yilanlik, Guobaoshan, and Shihuiyao. Detailed mineralogical and spectroscopic investigations were conducted, including X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectroscopy, together with major- and trace-element analyses by LA-ICP-MS.The results show that the mineralogical and spectral characteristics of amazonite are overall consistent with those of microcline, indicating that the primary crystal structure remains relatively stable. UV-Vis spectra generally display absorption peaks at 248 nm and 382 nm and a broad absorption band between 620 and 740 nm, suggesting that color-center absorption is closely associated with the blue green hue. Trace-element data reveal systematic enrichment of Rb, Cs, and Pb in amazonite. Integrating these observations, we propose that the blue–green coloration of amazonite is unlikely to be controlled by a single element; instead, it is more plausibly related to the coupled enrichment of Rb and Pb via isomorphous substitution for K in the feldspar lattice. Substitution of Rb⁺ for K⁺ induces subtle lattice adjustments, whereas substitution of Pb²⁺ for K⁺, owing to charge imbalance, more readily generates localized defects that facilitate the formation of color centers, ultimately producing the characteristic blue green coloration. This interpretation is further supported by the UV-Vis responses linked to color-center absorption. Based on comparisons with previous studies, amazonite in the southern CAOB is inferred to have formed predominantly during the late stage of highly fractionated granitic magmatism, closely associated with the enrichment of rare metals (Rb\Cs) and the role of volatiles (e.g., F). Amazonite is therefore suggested to be a useful indicator mineral for Rb-related rare-metal mineralization in granitic systems.

Crystal-rich fluid inclusions serve as a crucial carrier in the evolution of pegmatitic melts-fluids, providing the most direct evidence for unraveling the origin, migration, phase transitions, and associated element enrichment mechanisms of pegmatitic fluids. The Jing'erquan rare metal deposit is a typical granite-pegmatite type lithium-beryllium deposit in the East Tianshan, western Central Asian Orogenic Belt. However, the source and evolutionary characteristics of its ore-forming fluids remain unclear. This study conducted detailed petrographic observations, along with laser Raman spectroscopy, microthermometry, gas chromatography, and ion chromatography analyses on fluid inclusions from pegmatites in this deposit. The results indicate that the fluid inclusions at Jing'erquan are diverse in type. They are generally characterized by moderate-low temperatures (mainly ranging from 240 ℃ to 380 ℃) and salinities (predominantly between 1.0 wt% NaCl_eqv and 5.5 wt% NaCl_eqv), as well as low densities (0.5～0.9 g/cm³). The fluid is rich in CO₂, H₂O, and N₂, with minor amounts of C₂H₂ and CH₄, and is relatively enriched in F⁻, Cl⁻, and alkali metal cations. This study proposes that the ore-forming fluids for the Jing'erquan Li-Be deposit were primarily magmatic in origin, resulting from the high fractional crystallization of granitic magma in a relatively closed environment. Two distinct pegmatite veins, dominated by spodumene and beryl, respectively, were formed during different stages of granitic magma differentiation. During the mineralization process, the fluid properties transitioned from moderate-low temperature-low salinity-low density to low temperature-moderate-low salinity-low density. The primary reason for this shift is that CO₂ gradually reached saturation and separated from the ore-forming fluid, as the temperature, pressure, and solubility of CO₂ and NaCl-H₂O decreased. In this process, CO₂ acted as an important carrier, facilitating the transportation and enrichment of lithium. Furthermore, the relative enrichment of F⁻, Cl⁻, and alkali metal cations played a significant role. Specifically, F⁻ was conducive to the formation of complexes or compounds with rare metal cations such as Li⁺ and Be²⁺, aiding their migration and subsequent precipitation and enrichment to form ore.

The Western Tianshan Orogen is located in the southwestern Central Asian Orogenic Belt (CAOB). The widespread magmatic rocks provide a critical window for investigating regional tectonic-metallogenic dynamics. To address controversies regarding the petrogenesis, tectonic setting of granitoids, and the closure timing of the North Tianshan Ocean in the Western Tianshan region, this study focuses on the Late Paleozoic granitoids (Guozigou, Halegati, Jinghe, and Nalati plutons) located along the northern margin of the Yili Block, through integrating geochronological, whole-rock elemental, and Sr-Nd-Hf isotopic analyses. The studied plutons are predominantly composed of monzonitic granite and potash feldspar granite. Zircon LA-ICP-MS U-Pb dating reveals that these plutons were emplaced between (368.1±1.5) Ma (Late Devonian) and (301.9±2.8) Ma (Late Carboniferous). Combined with regional geochronological data, the magmatism in the northern Yili Block can be temporally subdivided into two stages, late Devonian to early Carboniferous and late Carboniferous. The studied granitoids exhibit high silica (SiO₂ = 66.62%–76.08%) and total alkali (K₂O+Na₂O=6.72%–8.85%) contents. In terms of rare earth elements, the studied samples show LREE-rich patterns with variable negative Eu anomalies (δEu = 0.30–0.97). The trace element patterns of the studied rocks are characterized by enrichment in Rb and Th and depletion in Nb, Ta, and Ti, comparable to those of continental arc granites. The late Devonian granitoid samples show slightly enriched radiogenic isotopic signatures, with negative ε_Nd(t) from –3.79 to –1.3 and ε_Hf(t) from +0.3 to +5.0, indicating magma sources dominated by ancient crustal materials with mantle-derived contributions. In contrast, the Late Carboniferous granitoids show more radiogenic ε_Nd(t) (+0.8 to +5.9) and ε_Hf(t) (+4.1 to +15.1) values, indicative of a juvenile lower crustal origin. Integrating previous studies, we propose that the 368–307 Ma granitoids are of I-type granite and were formed associated with the northward subduction of the Northern Tianshan Ocean beneath the Yili Block, whereas later A2-type potash feldspar granites and I-type monzonitic granites in the context of post-collisional lithospheric delamination initiated at ～305 Ma. Additionally, the Late Devonian-Early Carboniferous to Late Carboniferous granitoids in the Borohoro region exhibit significant potential for Cu-Mo mineralization.

Eudialyte is a critical ore mineral enriched in zirconium, niobium, and rare earth elements (Zr-Nb-REE), and often occurs in peralkaline rocks. Its composition records key information from magma genesis, evolution, to hydrothermal activities, providing important insights for evaluating the metallogenic potential of alkaline rocks. The Bashisuhong complex is located in the junction zone between the Northern Tarim Basin and the South Tianshan Orogen, where aegirine-augite syenite dikes host Zr-Nb-REE mineralization. These dikes, exhibiting a gray-black to purplish-red coloration, display irregular contact boundaries with the marble and locally visible plastic flow structures. Wollastonite-rich wall-rock xenoliths are commonly observed within these dikes, indicating material exchange with the marble. The dikes are 0.33–3.71 m wide, extend 30–170 m, and are generally oriented east-west. Gangue minerals primarily consist of perthite, aegirine-augite, and wollastonite, while ore minerals are mainly eudialyte, apatite, and titanite. Eudialyte is predominantly euhedral, with grain sizes ranging from 0.1 to 5 mm, and exhibits well-developed straight oscillatory zoning. Their trace element characteristics are controlled by charge-and-radius-controlled (CHARAC) substitution mechanisms, indicating a typical magmatic origin. Both whole-rock and eudialyte samples exhibit light rare earth element (LREE) enrichment and heavy rare earth element (HREE) depletion, accompanied by significant negative Eu and Sr anomalies, indicating extensive fractional crystallization of plagioclase in the primary magma of the syenite dikes and compositionally similar to alkaline basalt. When alkaline magma intruded into marble, assimilation of the marble introduced substantial CaO components. This assimilation not only supplied critical materials for eudialyte formation but also, through increased CaO content, enhanced Cl solubility and lowered the solidus temperature, thereby facilitating further magma evolution and achieving supernormal enrichment of rare metals. Therefore, the interaction between alkaline magma and marble represents a crucial mechanism for eudialyte mineralization in the junction zone between Northern Tarim Basin and South Tianshan Orogen, making their contact zones promising targets for rare metal exploration.

The Beishan Orogenic Belt, situated in the central segment of the southern margin of the Central Asian Orogenic Belt (CAOB), has undergone prolonged, multi-stage subduction and accretion. It represents a key region for reconstructing the tectonic evolution of the southern CAOB margin and the closure of the Paleo-Asian Ocean. The Early Paleozoic was a significant crustal evolution period for the Beishan Orogenic Belt, characterized by frequent magmatic activity. Previous studies primarily focused on the central-western part of the belt, reporting a magmatic flare-up at 450−420 Ma. This study presents systematic geochronological and geochemical investigations of the Waizuishan pluton, located on the southeastern edge of the Shuangyingshan-Huaniushan tectonic unit within the Beishan Orogenic Belt. The Waizuishan pluton mainly comprises quartz diorite (and granodiorite. Zircon U-Pb dating yielded crystallization ages of (427.1±3.4) Ma and (418.6±2.8) Ma. The rocks belong to the metaluminous series (A/CNK＜1), exhibiting calc-alkaline and magnesian affinities. They possess low total rare earth element (ΣREE) contents, are enriched in light rare earth elements (LREEs), and show weak negative Eu anomalies (δEu=0.72−0.86). Geochemically, they are enriched in large-ion lithophile elements (LILEs: e.g., Rb, Th, U, K, Pb) and depleted in high-field-strength elements (HFSEs: e.g., Nb, Ta, P, Zr, Ti). Zircon εHf(t) values range from −2.0 to 0.6, corresponding to Hf crustal model ages (T_DMC) of 1.53−1.36 Ga. The geochemical signatures indicate that the Waizuishan pluton is an I-type granite formed within a subduction-related continental margin igneous arc. It was derived predominantly from the remelting of Mesoproterozoic crustal material with minor contributions from mantle-derived components. Nearly contemporaneous magmatism occurred within all four tectonic units of the Beishan Orogenic Belt. Zircon Hf model ages from Paleozoic igneous rocks (500−350 Ma) exhibit prominent peaks at 1.5−1.4 Ga and 0.8−1.0 Ga, correlating with Mesoproterozoic (～1.4 Ga) and Neoproterozoic (～0.9 Ga) tectonothermal events. This suggests that the various tectonic units of the Beishan Orogenic Belt likely share a common source region. Comparisons with the Yili Block and Central Tianshan Block indicate that these three terranes show stronger affinities with the Baltica and Laurentia cratons, whereas they lack affinity with the Tarim Craton, as represented by the Dunhuang Block.

The Mazongshan arc is an important component of the Beishan orogenic belt, and its widely distributed Early Paleozoic intrusive rocks are of great significance for studying the early Paleozoic tectonic and magmatic evolution in the Beishan area. This study conducted petrological, geochemical, and zircon U-Pb geochronological studies on the Pochengshan granodiorite in the Mazongshan arc. The LA-ICP MS zircon U-Pb age is 451.4 ± 1.9 Ma (MSWD=1.2), indicating an early Late Ordovician period. The rock has high SiO₂ (62.25-69.6%), Al₂O₃ (14.34-14.68%), Na₂O+K₂O (6.07-6.44%), and is a high potassium calcium alkaline, quasi aluminous granite. The distribution curve of rare earth elements shows a gentle right tilt, with light rare earth elements slightly enriched, enriched in large ion lithophilic elements (such as Rb, Ba, Th, K), and depleted in high field strength elements (such as Nb, Ta, Sr, P, Ti). The geochemical characteristics indicate that the Pochengshan granodiorite is a product of partial melting of the newly formed lower crust under the influence of mantle derived magma intrusion in a subduction environment, and the magma source area has been subjected to the alteration of subduction zone fluids and the addition of mantle derived components. It is a response to the northward subduction of the early Late Ordovician in the ancient ocean represented by the Hongliuhe Niujuanzi Xichangjing ophiolite.

The Beishan region of Gansu Province forms a significant metallogenic belt for non-ferrous and precious metals within the Central Asian Orogenic Belt in northwestern China, and has long been a focal area for mineral exploration and research. Recently discovered through systematic geological surveys in this region, the Dongshuangjingzi iron deposit is a medium-sized hematite resource. This paper systematically describes the deposit's geological characteristics, defines its ore types and mineral assemblages, analyzes its genetic mechanism, and evaluates the area's prospecting potential. The aim is to provide a scientific basis and new insights for regional iron ore exploration. The study employed an integrated methodology, including geological mapping, high-precision magnetic surveys, engineering verification, systematic petrographic and ore microscopic observations, phase analysis, and regional stratigraphic and tectonic analysis. This approach was used to constrain the deposit's metallogenic epoch and tectonic setting. Results indicate that the ore bodies are primarily hosted within low-grade metamorphic sedimentary rocks, with their occurrence strictly controlled by the host stratigraphy. The dominant natural ore type is hematite-quartzite, accompanied by minerals such as limonite, siderite, and magnetite. The ore typically exhibits a banded structure, characteristic of sedimentary-metamorphic iron deposits. Based on petrographic, geochemical, and regional geological evidence, the Dongshuangjingzi deposit is interpreted as a Paleoproterozoic sedimentary-metamorphic iron formation, subsequently modified by regional metamorphism. The spatial distribution of ore bodies, combined with stratigraphic, structural, and magnetic anomaly data, suggests that the deep and lateral extensions of the iron-bearing formations hold significant prospecting potential. Synclinal structures hosting the banded iron formation are identified as key geological indicators for exploring similar deposits. Therefore, subsequent exploration should prioritize the core and flanks of these synformal structures. This discovery enhances the understanding of metallogenic types in the Beishan belt and provides a new direction for regional iron ore prospecting.

The Shahongshan pluton is located at the junction of Gansu Province and Inner Mongolia, which is at the intersection of the North China plate, the Tarim plate and the Kazakhstan plate. In addition, the tectonic magmatic activity is widely distributed. In this paper, the LA-ICP-MS zircon U-Pb dating, petrology, major and trace element analysis were carried out on the rocks of Shahongshan pluton, including granite porphyry and syenogranite, in order to unravel the regional intrusion age, rock genesis and the tectonic evolution of the Beishan orogenic belt. LA-ICP-MS Zircon U-Pb dating show that the weighted average age of the granite porphyry and syenogranite was (294.7±4.0) Ma, and (284.2±4.0) Ma, respectively, indicating that they formed in Early Permian. Petrological geochemical analyses show that granites of the Shahongshan pluton belong to calcium-alkaline to high potassium-calcium alkaline rock series, which are characterized by high silicon (74.79%～76.28%), alkali-rich (6.01%～8.30%), and aluminous (A/CNK=1.40～1.89). The total amount of rare earth elements was high, with enrichment in the light rare earth element (LREE; average 251.60×10⁻⁶) and depletion in the heavy rare earth element (HREE; average 45.52×10⁻⁶). The standardization curve of chondrite meteorite was significantly right-tilted, the LREE/HREE ratios of 5.35～5.68 and La_N/Yb_N values of 7.93～9.81, indicating a remarkable fractionation of light and heavy rare earths elements. The samples had obvious negative Eu anomalies. Trace elements are relatively enriched with large ionic lipophilic elements Rb, strong incompatible elements Th, U and high field strength elements Zr and Hf, and significant losses are lost to high field strength elements Ba, Nb, Ti and P. In combination with the regional geological background, The A-type granite, represented by the flesh red granite porphyry, was formed in an extensional environment and has specific petrological, mineralogical and geochemical characteristics. Its magma source is mainly crust-derived material, and may be mixed with a small amount of mantle-derived material. The I-type granites, represented by the flesh red syenogranite, may be related to the crystallization differentiation of mantle-derived magma, the partial melting of metamorphic igneous rocks in the lower crust, or the remelting of crust sediments modified by mantle-derived magma. The formation of the Shahongshan pluton is related to the post-collisional tensile environment and local compressive stress in the Early Permian, and has undergone complex processes of magma ascent, separation and crystallization, assimilation and contamination, and mixing. It is concluded that the tectonic background of Shahongshan pluton is the post-collisional plate rift valley environment.

As a key tectonic unit in the southwestern margin of the Central Asian Orogenic Belt（CAOB）, the West Junggar region is critical for clarifying the provenance system and tectonic setting of the Late Paleozoic Kujiertai Formation. In this study, clastic rocks of the Kujiertai Formation were selected as the research object, and systematic LA-ICP-MS detrital zircon U-Pb dating and trace element analysis were carried out. A high-precision detrital zircon age spectrum and a supporting geochemical database of the formation were established. Combined with the method for reconstructing crustal thickness using zircon Eu anomalies, these data provide important constraints for revealing the provenance characteristics and tectonic evolution background. The results show that the Th/U ratios of detrital zircons from the Kujiertai Formation range from 0.81 to 4.03 (all greater than 0.4), indicating a typical magmatic origin. The zircon U-Pb age spectrum shows that the main ages are concentrated in the range of 510–290 Ma, with five distinct peak intervals: 430–390 Ma, 380–365 Ma, 365–340 Ma, 340–320 Ma and 320–290 Ma. Among them, the youngest zircon age is 298 Ma, which provides key chronological constraints on the sedimentary age of this stratigraphic sequence, suggesting that the sedimentation occurred no earlier than the Early Permian. Geochemical characteristics reveal that the provenance is dominated by acid granite (accounting for approximately 68%) and mafic basalt (accounting for approximately 30%), reflecting prominent magmatic rock features in the provenance area. Integrating with the regional geological background, this study holds that the provenance system of the Kujiertai Formation is mainly controlled by the multi-stage tectono-magmatic activities of the Boshkul-Junggar Magmatic Arc, the Zarma-Sawuer Magmatic Arc and the Darbut Ophiolite Belt. Through systematic analysis of zircon Eu anomaly characteristics and combined with the timing of regional magmatic activities, the Paleozoic crustal thickness variation sequence of the study area was reconstructed. This result provides independent geochemical evidence for clarifying the complex tectonic evolution process of "accretion-transformation-disturbance adjustment" experienced by the West Junggar region during the Paleozoic Era.

The Tarim Large Igneous Province constitutes the most significant tectono-thermal event in the evolution of the Tarim Craton, forming mafic-ultramafic layered intrusions (e.g., the Wajilitag complex) that host vanadium-titanium magnetite deposits. However, intermediate rocks identified at the margin of the Wajilitag intrusion have been largely overlooked. Thus, the magmatic evolution and deep-seated geodynamic processes of the Tarim Large Igneous Province have been incompletely understood. This study presents a comprehensive investigation of the Wajilitag biotite monzodiorite, integrating detailed petrographic, geochronological, and geochemical analyses. The biotite monzodiorite is primarily composed of plagioclase, orthoclase, biotite, hornblende and augite. LA-ICP-MS zircon U-Pb dating yields an age of 277.9±1.5 Ma (MSWD = 0.85), constraining the emplacement of the biotite monzodiorite in the Early Permian. This age is slightly younger than that of the Wajilitag mafic-ultramafic layered intrusion. The biotite monzodiorite is characterized by relatively low silica (SiO₂content is 52.14%–53.50%) and high alkali contents (Na₂O+K₂O content is 7.26%–7.60%), classifying it as shoshonitic series. The chondrite-normalized REE pattern displays a right-sloping trend with LREE enrichment and HREE depletion. It is enriched in large-ion lithophile elements (LILEs; e.g. Ba and Pb) and possesses high concentrations of high-field-strength elements (HFSEs; e.g. Nb, Ta, Zr, Hf), without Nb-Ta negative anomalies. These geochemical features are indicative of an OIB-like enriched mantle source, with negligible crustal contamination during ascent. The slightly enriched zircon Hf isotopic composition (εHf(t) value range from −1.8 to −4.4) of the Wajilitag biotite monzodiorite is similar to that of continental flood basalts from the Tarim Large Igneous Province. In the TiO₂-MnO-P₂O₅ and Hf-Th-Ta tectonic discrimination diagrams, the rocks exhibit an affinity consistent with within-plate basalts. Integrated studies suggest that the Wajilitag biotite monzodiorite was derived from partial melting of an enriched lithospheric mantle that had been modified by subducted oceanic crust, with eclogite as the residual phase in the source. The interaction between a mantle plume and the subducted slab played a significant role in its formation.

Xishenba mafic-ultramafic intrusion is located on the northern margin of the Yangtze Craton. It is a newly discovered magmatic Cu-Ni mineralized intrusion in Hannan, Shaanxi Province, with significant mineralization potential. The intrusion consists of lherzolite, olivine lherzolite, and gabbro. The ore bodies are predominantly hosted within the lherzolite unit, with sulfides mainly comprising pyrrhotite, pentlandite, and chalcopyrite. Zircon U-Pb concordant age of the Xishenba intrusion is （854±3）Ma, indicating that it was formed in the middle Neoproterozoic. Geochemically, gabbro exhibit right-inclined REE patterns characterized by light rare earth element (LREE) enrichment and heavy rare earth element (HREE) depletion. In contrast, olivine lherzolite and lherzolite display relatively flat REE patterns with slight LREE enrichment. All samples are enriched in large ion lithophile elements (Rb, K) and depleted in high field strength elements (Nb-Ta, Zr-Hf).These geochemical characteristics are similar to those of other Neoproterozoic mafic–ultramafic intrusions along the northern margin of the Yangtze Block and global island arc basalts, suggesting a plate convergence setting. Olivine crystals from the ore-bearing lherzolite have Fo value of 76.0～80.9 mol%, Ni content of <200×10⁻⁶ to 1445×10⁻⁶. The correlation between these parameters suggests that sulfide segregation occurred in the parental magma of the Xishenba intrusion. Zircon from the lherzolite yield ε_Hf(t) value of −6.82～4.84, indicative of a depleted mantle source. Modeling based on Hf isotopes and Th/Yb–Nb/Yb systematics suggests that the magma experienced 10%~30% crustal contamination during ascent, which was likely the key factor triggering sulfide segregation. Comparative analysis with magmatic deposits formed in convergent settings, such as those at Xiarihamu, Kalatongke, and Sibao, reveals that the Xishenba Cu–Ni deposit possesses significant mineralization potential. Consequently, similar types of mafic-ultramafic intrusions along the northern margin of the Yangtze Block should be prioritized as targets for future Cu–Ni exploration.

The Erlian basin, an essential sandstone-type uranium enrichment basin in northern China, is situated in the central segment of the Central Asian Orogenic Belt. In the basin, the Lower Cretaceous Saihan Formation constitutes the most significant uranium-bearing layer. Influenced by tectonic overturning and paleo-valley evolution, provenances experienced intensely spatial and temporal transition, and the precise depositional age of the Saihan Formation remains ambiguous. In this study, we conducted an integrated investigation of the Saihan Formation in the Naomugen Depression, employing petrographic analysis, LA-ICP-MS U-Pb geochronology and trace element geochemistry of detrital zircons. These methodologies are to determine the maximum depositional age, identify provenance characteristics of the uranium-bearing sandstones, and elucidate tectonic implications. Detrital zircon geochronological results reveal three predominant age clusters: 434 Ma (Caledonian), 265 Ma (Variscan), and 140 Ma (Yanshanian), indicating multiple magmatic sources spanning the Paleozoic to the Early Mesozoic. Notably, the youngest single-grain ages (125±3 Ma, 115±6 Ma, 122±2 Ma, 108±2 Ma) and weighted mean ages (113.3 Ma, 123 Ma) collectively constrain the maximum depositional age of the Saihan Formation to (108±2) Ma, corresponding to the Albian stage of the Early Cretaceous. Provenance analysis demonstrates that detrital materials were derived from: Cretaceous exposures in the central-western Sonid Uplift, Weijing intrusions in the Bayinbaolige Uplift, and Caledonian-Variscan complexes in the western Bainaimiao Arc. Integrating with volcanic records from the Tengger Formation, our findings confirm a rapid tectonic uplift event at ～110 Ma during the late Early Cretaceous. This tectonic episode created optimal metallogenic conditions through the formation of structural slopes and thick sandstone sequences, providing critical constraints for uranium exploration models in the region.

The sandstone uranium mineralisation found in the Santang Lake Basin is primarily located in the Hanshuiquan area, with the ore-endowed stratigraphy concentrated in the Neoproterozoic Changji River Group. In order to accurately and objectively evaluate the mineralisation conditions and prospects of the Hanshuiquan area in the Santang Lake Basin, the identification of interlayer oxidation zones and an understanding of the uranium mineralisation conditions are crucial. In this paper, the focus is on the Neoproterozoic Changji River Group. In order to identify the yellow sandstones, geochemical indexes of altered sandstones, constant and trace element analyses of rocks and ores, and physicochemical parameters of fluid action are employed. The grey-green, grey and grey-white sandstones containing minerals or anomalies are considered to be the transition zone, while the red sandstones and grey sandstones are the reductive zone. The grey-green, grey and grey-white sandstones are the result of oxidation, while the red sandstones and grey sandstones are the result of reduction. The oxidised red sandstones present in this area are the result of primary deposition under arid climatic conditions, while the yellow sandstones are interlayer oxidation zones formed by post-oxidation and control uranium mineralisation. It would be beneficial to trace the alteration front of the yellow sandstone in order to reduce the cost of exploration. Some of the geochemical indicators provide evidence that this red sandstone is a product of sedimentary diagenesis. This is evidenced by the higher organic carbon (Orgc), CaO, Cu/Al, Ni/Al and Cd/Al contents in the red sandstone than in the yellow sandstone, and the low temperature of fluid action at which it was formed. The in situ pyrite sulfur isotope signature of the microzone indicates an interstratified oxidized zone type of uranium deposit. The very restricted distribution of white and green sandstones suggests a weak but hydrocarbon-influenced influence. The analysis of tectonic, topographic, geomorphological and hydrological conditions, lithology, petrography and post-generation alteration conditions indicates that this area has certain conditions conducive to uranium mineralisation. However, there are some key deficiencies, including insufficient reductant capacity, weak oil and gas dissipation and the absence of uranium ore enrichment.

The sandstone-type uranium deposit in the Kelulun Depression is the first industrial uranium deposit discovered in the Hailar Basin. In order to preliminarily identify the types, occurrence characteristics, and mineralization significance of uranium minerals in the study area, this paper conducts a systematic study of the ore-bearing sandstone in the target layer by using polarized light microscopy combined with electron probe analysis on the basis of a field investigation. The results show that uranium mineralization in the study area occurs at the front edge of the braided river delta of the Yimin Formation. The rock type of the ore-bearing target layer is mainly medium-fine-grained feldspathic litharenite, with the overall development post-generation alteration. Uranium minerals are mainly coffinite, followed by uranium-titanium oxide. Coffinite is mainly distributed in colloidal or stellate forms in or around pyrite, and a few are filled in the edges of debris particles or dissolution pits in irregular granular form. Uranium-titanium oxides are mostly distributed in irregular granular forms in the biotite cleavage cracks. The coffinite and uranium-titanium oxide, as the first discovered independent uranium minerals in the study area, fill the gap left by the absence of uranium minerals in the Hailar Basin. In terms of uranium mineralization conditions, the Permian granite and intermediate-acidic volcanic rocks in the west of the study area provide sufficient uranium sources for the sandstone-type uranium mineralization in the area. Under the action of reducing media such as oil and gas, organic carbon, and sulfides in the area, U⁶⁺ in the ore-forming fluid is reduced to U⁴⁺ and precipitated into mineralization in the form of coffinite and uranium-titanium oxide.

Fluorite is an indispensable raw material in strategic emerging industries such as new energy and new materials. In recent years, significant breakthroughs have been achieved in fluorite exploration in the Altyn Tagh orogenic belt, with the discovery of world-class deposits such as Kaerqiaer, Piyazidaban, and Gajike. However, the nature of the ore-forming fluids and the genetic types of these deposits remain unclear. This study focuses on the Gajike fluorite deposit in the central and southern parts of the Altyn Tagh, conducting detailed geochemical research on trace elements in fluorite from different stages based on thorough geological characterization. The results indicate that fluorite from all stages is enriched in light rare earth elements, with rare earth element patterns showing a "right-leaning" type, and mineralization occurring during early hydrothermal activity. The Tb/La-Tb/Ca diagram suggests that fluorite is of hydrothermal origin, with hydrothermal fluids undergoing water-rock reaction with the surrounding rocks. The La/Ho-Y/Ho diagram reveals strong fractionation of Y and Ho, indicating that the fluorite exhibits homologous multi-stage characteristics, where early fluorite breccia underwent recrystallization while middle-stage fluorite cement precipitated during fluid migration. The δCe-δEu diagram shows strong negative Eu anomalies and positive Ce anomalies in fluorite, reflecting a medium-low temperature reduction environment with low oxygen fugacity and water-rock reaction effects. The high F content in the rock mass and the Ca-rich strata suggest that the F in fluorite originates from K-feldspar granite, while Ca comes from metamorphic strata and marble. Comprehensive analysis concludes that the Gajike fluorite deposit formed in a medium-low temperature reduction environment, and its genetic type is classified as a medium-low temperature hydrothermal deposit.

Early Paleozoic stratigraphic sequences are well exposed in the North Altyn ophiolitic mélange zone and its adjacent Central Altyn block, which documented the subduction and collision of the North Altyn Ocean. The Ordovician sequence within the North Altyn ophiolitic mélange zone is composed of clastic rocks, volcanic rocks and carbonates. Detrital zircon grains from the volcaniclastic sandstone samples determine a single age population at 420～440 Ma (peak at 470 Ma), with a maximum depositional age (YPP) of 456 Ma. Moreover, the detrital grains were predominantly derived from a juvenile crustal source (7.4＞ε_Hf(t)＞0). Coeval Ordovician Elantage Formation exposed in the northern margin of the Central Altyn block also displays a single age population, but at 510～450 Ma (peak at 470～465 Ma), with a YPP of 446 Ma. However, their Hf isotopes (−1.8～−8.4) indicate a source region dominated by crustal recycling. The zircon trace element signatures of both units argue for derivation from a granitic source. Field geology, detrital zircon age distribution patterns, along with zircon isotopic and geochemical compositions, suggest deposition in an active plate margin setting. This, together with regional geology and previous studies, favors the Elantage Formation as deposited in an Early Ordovician retro-continental arc basin related to the south directed subduction of the North Altyn Ocean, with detritus derived from the Cambrian-Ordovician continental margin arc type granitoids in the northern Central Altyn block. In contrast, the Ordovician sequence within the North Altyn ophiolitic mélange zone may have been deposited in a younger fore-arc basin, subsequent to retreat of oceanic subduction and the extension of the continental central Altyn block. The identified Ordovician continental arc margin basins argue for continuous subduction of the North Altyn Ocean from the Cambrian to the Ordovician period, which closed in late Ordovician.

The North China Craton underwent a prolonged and complex geological evolution during the Archean to Paleoproterozoic, with the magmatic and metamorphic processes remain as the research questions. This study focuses on the TTG (tonalite-trondhjemite-granodiorite) gneisses of the Taihua Group in the Xiong’ershan area along the southern margin of the North China Craton. The integrated field investigations, petrographic analysis under the microscope, geochemistry, zircon U-Pb dating and Hf isotopic studies are conducted to elucidate the Paleoproterozoic magmatic mechanisms and the tectonic evolution of this region. Zircon U-Pb dating constrains the magmatic crystallization age of the Taihua Group TTG gneisses in the Xiong’ershan area to approximately 2300 Ma, while the metamorphic ages range from 1984 Ma to 1940 Ma. The Taihua Group TTG gneisses exhibit a wide compositional range, with SiO₂ (59.35%～70.78%), Al₂O₃ (12.41%～17.93%), and relatively high CaO (1.40%～5.52%) and MgO (0.95%～2.56%) contents. It is enriched in light rare earth elements (LREE) and depleted in heavy rare earth elements (HREE), displaying strong fractionation between LREE and HREE. In composition, it resembles high-Al TTG gneisses. The samples are enriched in large-ion lithophile elements (LILEs) such as Rb, Ba, and Sr, but depleted in high-field-strength elements (HFSEs) like Nb, Ta, and Ti, which are similar to the features of island arc granites. Additionally, magmatic zircons display relatively high (¹⁷⁶Hf/¹⁷⁷Hf)ᵢ ratios (0.281282～0.281332), εHf(t) values (−2.98 ～ +0.20), and two-stage model ages (2844～2994 Ma), indicating that the magmatic source originated from the partial melting of Mesoarchean ancient crust. These findings suggest that the TTG gneisses in the Xiong’ershan area formed during the Paleoproterozoic subduction process between the eastern and western blocks of the North China Craton. The metamorphic age of 1984～1940 Ma records the collisional process along the Trans-North China Orogeny. This further constrains the timing of collision between the eastern and western continental blocks.

The genetic mechanism of serpentinized peridotite in Lüliangshan area of the North Qaidam UHPM belt is controversial. It was proposed as product of subducted slabs, refertilised lithospheric mantle or mantle wedge. In this paper, two types of peridotite (garnet lherzolite and dunite) were collected from Lüliangshan area, and the major and trace elements, and in-situ boron isotope of serpentine were analyzed. The two types of peridotite have experienced different types of serpentinization respectively. The dunite is dominated by the serpentinization of olivine, while the garnet lherzolite is dominated by the serpentinization of pyroxene. The serpentine produced by the serpentinization of olivine has higher content of MgO and As but lower content of Al₂O₃, Cr₂O₃, FeO, Li, Yb, Y, Ti, Sc and Zn; while the serpentine produced by the serpentinization of pyroxene is opposite. Serpentine in two types of peridotite showed significant differences in boron isotope. The boron content of serpentine in dunite is from 13.3×10^–6 to 38.5×10^–6, and its δ¹¹B value is from −9.5‰ to +5.0‰, which is close to or slight higher than the δ¹¹B value of the mantle. The boron content of serpentine in garnet lherzolite is from 10.5×10^–6 to 49.9×10^–6, and its δ¹¹B value is from 6.3‰ to 23.0‰, indicating that they are significantly enriched in heavy boron isotope. The difference of boron isotope composition of serpentines indicates that the Lüliangshan peridotite was formed in two different tectonic settings. The garnet lherzolite is formed in lithospheric mantle and has been altered by seawater, thus with enrichment of heavy boron isotope. While the dunite is of mantle-wedge origin and had undergone serpentinization interacted with subduction fluids, thus with enrichment of light boron isotope.

The marine carbonate rock series of the Ordovician Majiagou Formation in the central and eastern part of the Ordos Basin has great natural gas exploration potential. However, the hydrocarbon accumulation mechanism is complex. Studying the hydrocarbon accumulation stages and patterns of this formation series is of great significance for regional oil and gas exploration geological evaluation. In this paper, petrography of inclusions and homogenization temperature analysis were carried out on the carbonate rock samples of the Ordovician Majiagou Formation in the basin, and the PetroMod software was used to restore the thermal evolution history of the Ordovician. The results show that two phases of hydrocarbon fluid inclusions have developed in the carbonate rock series of the Majiagou Formation. The first phase is mainly hosted in the dissolution pores of calcite and dolomite, with a homogenization temperature of 110–130 ℃, and the corresponding natural gas charging period is 210–165 Ma (from the end of the Triassic to the end of the Middle Jurassic). The second phase is mainly hosted in the dolomite veins or late-stage calcite, with a homogenization temperature of 160–170 ℃, and the corresponding natural gas charging period is 123–97 Ma (the end of the Early Cretaceous). The Ordovician in the central and eastern part of the basin has experienced three thermal evolution stages: a slow heating stage before the Late Permian, a rapid heating stage from the end of the Late Permian to the end of the Early Cretaceous, and a cooling stage after the Early Cretaceous. The charging of natural gas in both phases occurred during the rapid heating stage, with an average heating rate of 0.86 ℃/Ma. The Ordovician carbonate rock reservoir is in direct contact with the coal-measure source rocks of the Upper Paleozoic in the upper part, and has a self-generation and self-reservoir input from the sub-salt marine source rocks in the lower part. The natural gas migrates along the pores and fractures and accumulates in the lithologic traps of dolomite. Since the Late Cretaceous, the basin has been uplifted and cooled, with an average cooling rate of 0.63 ℃/Ma, and the hydrocarbon generation of the source rocks has ceased.

Ecuador has a relatively low level of geological exploration but possesses significant potential for copper resources. It has emerged as a hotspot for copper exploration and development on a global scale. Currently, investment in copper exploration and development ranks first among all mineral types and is experiencing rapid growth. This sector is primarily dominated by mining companies from Europe and the United States, although China and Ecuador also play important roles. Since the beginning of the 21st century, substantial progress has been made in the exploration and development of copper resources. Four major copper deposits have been discovered, leading to a rapid increase in reserves, resources, and production. Over the past decade, the total of new reserves and resources has accounted for 11.56% of the global increase, positioning Ecuador fourth in the world. From 2019 to 2024, the output of copper has surged by more than 15 times, which has become a crucial source for China's copper resource security. By systematically analyzing the endowment characteristics and the current status of exploration and development of Ecuador's copper resources, along with the country's resource and investment environment, this paper evaluates the investment potential of copper ore, as well as the opportunities and risks involved. It is recommended that Chinese enterprises enhance their research on the rules of copper mineralization, focus on the changes in mining rights registration and mining laws, and stay informed about the latest discoveries in major copper projects .

Objective: To address the unclear grout diffusion mechanism and the insufficient understanding of geoelectrical response characteristics during grouting in saturated sand strata, indoor grouting simulation experiments were conducted to investigate the grout diffusion behavior and its geoelectrical response characteristics in saturated sand layers, so as to provide a theoretical basis for real-time monitoring and performance evaluation of grouting-based water control and strata reinforcement in underground engineering. Methods: A saturated sand layer was constructed in a three-dimensional physical model with dimensions of 82 cm × 82 cm × 82 cm, and grouting experiments were carried out under a grouting pressure of 0.3 MPa. Based on the indoor three-dimensional model and a parallel electrical monitoring system, the exciting current, self-potential, primary field potential, and apparent resistivity were dynamically monitored throughout the entire grouting process. The spatiotemporal evolution characteristics of these electrical parameters during grout diffusion and consolidation were then systematically analyzed. Results: The experimental results showed that the exciting current was a sensitive electrical parameter for characterizing the grout diffusion and consolidation processes, effectively reflecting the advance of the grout front and the evolution of conductive pathways. At the initial stage of grouting, the exciting current decreased from approximately 0.75 mA to 0.65 mA. Subsequently, with the displacement and mixing of grout and pore water, the electrical conductivity increased, and the exciting current rose to approximately 0.80 mA before gradually stabilizing. Both the self-potential and primary field potential exhibited pronounced fluctuations and increasing trends during grouting, which effectively revealed the migration pathways and diffusion range of grout at different strata levels. Owing to the heterogeneity of the weathered zone, the variations in electrical parameters were more complex, with stronger spatial differences and instability, whereas the responses in the saturated sand layer were relatively consistent. The three-dimensional inversion results of apparent resistivity indicated that the resistivity generally decreased first and then increased during the grouting process. During the grouting stage, grout entered the formation and mixed with pore water, forming a low-resistivity zone of approximately 50 Ω·m. During the consolidation stage, as cement hydration intensified and pore spaces were progressively filled, the free water content decreased and the conductive pathways within the pores were weakened, resulting in a gradual increase in resistivity to above 150 Ω·m. Conclusions: Grout diffusion and consolidation in saturated sand strata induce significant geoelectrical responses during the grouting process. Among the monitored parameters, the exciting current is the most sensitive to the advancing grout front and consolidation evolution, while the self-potential, primary field potential, and apparent resistivity can characterize grout migration and consolidation features from different perspectives. Grout consolidation in saturated sand strata exerts a pronounced weakening effect on conductive pathways, leading to significant electrical property variations. The results of this study can provide a reference for the real-time monitoring, dynamic identification, and engineering evaluation of grouting-based water control and reinforcement effects in underground engineering such as coal mines.