The Dengshang Mo deposit is a recently recognized porphyry-type system within the Yanliao Mo metallogenic belt of northern Hebei Province. However, its ore-hosting rhyolitic porphyry emplacement age and petrogenesis remain insufficiently understood. This study integrates petrography, zircon U-Pb geochronology, Lu-Hf isotope analysis, zircon trace element geochemistry, and whole-rock major- and trace element data to investigate the petrogenesis of the Dengshang rhyolitic porphyry and its genetic relationship with Mo mineralization. The ore-hosting porphyry is predominantly composed of quartz and plagioclase phenocrysts. LA-ICP-MS zircon U-Pb dating yields an emplacement age of 168.3 +/- 1.2 Ma, indicating that the rhyolitic porphyry was emplaced during a Middle Jurassic magmatic episode. Petrological and geochemical characteristics classify the Dengshang rhyolitic porphyry as an I-type granite. Zircon epsilon(Hf)(t) values range from -0.93 to -7.29, corresponding to two-stage model ages (T-DM(2)) of 1.27-1.67 Ga, which suggests derivation from partial melting of the Mesoproterozoic lower crust. Zircon trace elements display significant positive Ce anomalies (delta Ce = 10.14-332.85), and calculated oxygen fugacities (Delta FMQ = -0.65 to +2.77; median = +0.51) indicate moderately oxidized magmatic conditions conducive to Mo enrichment. These results collectively imply that the Dengshang rhyolitic porphyry was emplaced at similar to 168 Ma associated with paleo-Pacific plate subduction. This geodynamic setting triggered partial melting of Mesoproterozoic lower crust, producing oxidized magmas that experienced fractional crystallization prior to shallow emplacement. Our findings elucidate the petrogenesis of the Dengshang rhyolitic porphyry and its control on Mo mineralization, and contribute new insight for understanding porphyry Mo genesis within the complex tectonic evolution of the Yanliao Mo Belt.

The Baiyun gold deposit in the Liaodong Peninsula, North China Craton, contains > 120 t of gold, but its mineralization age and genesis remain contentious. To constrain the timing of gold mineralization, we conducted in-situ LA-ICP-MS U-Pb dating of monazite and rutile from gold ores, together with zircon from mineralized dikes. U-Pb dating of monazite yielded a concordia age of 1806.0 +/- 38 Ma, which we interpret as Paleoproterozoic regional metamorphism instead of hydrothermal mineralization. Rutile yielded two age populations at 1083.0 +/- 37 Ma and 389.0 +/- 30 Ma, attributed to Mesoproterozoic and Paleozoic tectono-thermal events, respectively. Zircon yielded crystallization ages of 232.0 +/- 2.0 Ma for diorite porphyrite dike, 225.9 +/- 1.2 Ma for granodiorite dike, and 121.68 +/- 0.48 Ma for granite dike. Field and petrographic evidence indicate that all dated dikes predate gold mineralization. Therefore, the youngest magmatic zircon provides a maximum constraint on the timing of mineralization. Within the established regional geochronological framework, the data suggest that gold mineralization at Baiyun most plausibly occurred during the Early Cretaceous (ca. 120 Ma). To further elucidate its origin, we compare mineralization age, geodynamics, ore-forming fluid characteristics, and sources of gold-related metals and sulfur with those of well-characterized Jiaodong-type gold deposits. This comparison supports that Baiyun represents an Early Cretaceous Jiaodong-type mineral system, formed during lithospheric thinning driven by rollback of the Paleo-Pacific plate.

The Permian–Triassic magmatic record in the eastern Central Asian Orogenic Belt (CAOB) provides critical insights into the terminal stages of the Paleo-Asian Ocean (PAO) evolution, including collisional and post-collisional processes following its Late Permian closure. The northeastern China region, tectonically situated within the eastern segment of the CAOB, is traditionally known as the Xingmeng Orogenic Belt (XOR). This study integrates zircon U-Pb geochronology, whole-rock geochemistry, and zircon Hf isotopic analyses of intermediate-acid volcanic rocks and intrusive rocks from the former “Tongjiatun Formation” in the Faku area of northern Liaoning. The main objective is to explore the petrogenesis of these igneous rocks and their implications for the regional tectonic setting. Zircon U-Pb ages of these rocks range from 260.5 to 230.1 Ma, indicating Permian–Triassic magmatism. Specifically, the Gongzhuling rhyolite (260.5 ± 2.2 Ma) and Gongzhuling dacite (260.3 ± 2.4 Ma) formed during the Middle-Late Permian (270–256 Ma); the Wangjiadian dacite (243 ± 3.0 Ma) and Wafangxi rhyolite (243.9 ± 3.0 Ma) were formed in the late Permian-early Middle Triassic (256–242 Ma); the Haoguantun rhyolite (240.9 ± 2.2 Ma) and Sheshangou pluton (230.1 ± 1.7 Ma) were formed during the Late Middle-Late Triassic (241–215 Ma). Geochemical studies, integrated with the geochronological results, reveal distinct tectonic settings during successive stages: (1) Middle-Late Permian (270–256 Ma): Magmatism included peraluminous A-type rhyolite with in calc-alkaline series (e.g., Gongzhuling) formed in an extensional environment linked to a mantle plume, alongside metaluminous, calc-alkaline I-type dacite (e.g., Gongzhuling) associated with the subduction of the PAO plate. (2) Late Permian-Early Middle Triassic (256–242 Ma): Calc-alkaline I-type magmatism dominated, represented by dacite (e.g., Wangjiadian) and rhyolite (e.g., Wafangxi), indicative of a collisional uplift environment. (3) Late Middle-Late Triassic (241–215 Ma): Magmatism transitioned to high-K calc-alkaline with A-type rocks affinities, including rhyolite (e.g., Haoguantun) and plutons (e.g., Sheshangou), formed in a post-collisional extensional environment. This study suggests that the closure of the PAO along the northern margin of the North China Craton (NCC) occurred before the Late Triassic. Late Triassic magmatic rocks in this region record a post-orogenic extensional setting, reflecting tectonic processes following NCC-XOR collision rather than PAO subduction. Combined with previously reported age data, the tectonic evolution of the eastern segment of the CAOB during the Permian-Triassic can be divided into four stages: active continental margin (293–274 Ma), plate disintegration (270–256 Ma), final collision and closure (256–241 Ma), and post-orogenic extension (241–215 Ma).

Alkaline complexes host economically strategic deposits of rare metals such as niobium (Nb) and tantalum (Ta) and rare earth elements (REEs). However, their enrichment and metallogenic processes remain poorly understood. The discovery of the Saima alkaline complex-hosted Nb-Ta-REE deposit (also referred to as the Saima deposit) in the eastern Liaoning Province in Northeast China provides an ideal opportunity to address these challenges. Petrographic analysis indicates that the Saima deposit occurs in aegirine nepheline syenite, with primary ore minerals including loparite, columbite-tantalite, fergusonite, fersmite, betafite, and bastnaesite. These characteristics are consistent with typical alkaline rock-hosted rare metal and REE deposits. Using petrography, mineralogy, apatite U-Pb, trace element, and in situ Sr-Nd isotopic analyses, and pyrite S isotopic analysis of aegirine nepheline syenite associated with Nb-Ta-REE mineralization, this study explored the metallogenic ages and mechanisms, source, and tectonic setting of the Saima deposit. The apatites associated with Nb-Ta-REE mineralization exhibit uniform, concentric, and oscillatory zoning in cathodoluminescence (CL) images, as well as high (La/Yb)N ratios (124.62-11440.84) and nonsignificant Eu anomalies (delta Eu values: 0.68-0.85). These characteristics indicate a magmatic origin, suggesting that the Nb-Ta-REE mineralization occurred primarily during the early-stage crystallization of alkaline magmas. The laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) apatite U-Pb dating results indicate that the aegirine nepheline syenite has lower intercept ages of 232 +/- 7 Ma and 224 +/- 17 Ma. In combination with previous geochronological studies, this study proposed that the Nb-Ta-REE mineralization in the Saima deposit might have occurred during the early Late Triassic. The in situ apatite Sr-Nd isotopic analysis reveals that the apatites feature high 87Sr/86Sr ratios (0.70835 to 0.70879) and negative epsilon Nd(t) values (-17.21 to-10.71), while the pyrites associated with Nb-Ta-bearing minerals exhibit positive delta 34S values (+1.3 %o to + 3.5 %o). These findings suggest that the mineralized alkaline rocks originated from the partial melting of a metasomatized Nb-, Ta-, and REE-rich lithospheric mantle. Based on the regional geological setting, this study proposed that the ore-bearing aegirine nepheline syenite in the Saima deposit was formed in an extensional tectonic setting after the closure of the oceanic basin. The recycled continental crust of the ancient Yangtze Craton played a key role in the formation of the Triassic Nb-Ta-REE-bearing alkaline rocks, exemplified by the Saima alkaline complex, in the eastern Liaoning Province. The entire Triassic alkaline complex in the eastern North China Craton (NCC) possesses great potential for Nb-Ta-REE mineralization, necessitating further prospecting and exploration.

The eastern Liaoning-southern Jilin tectonic zone (also referred to as the Liao-Ji tectonic zone), a potential zone for rare-metal and REE mineralizations in China, hosts over 10 rare-metal and REE deposits and ore occurrences with varying scales and mineralization characteristics, which establish this zone as an ideal target for research on the metallogenic regularities of rare-metal and REE mineralizations.The study area resides in the northern part of the East Asian continental margin, lying on the overlapping part of the North China and the Western Pacific Plates, is located in the northeastern North China Plate, consisting of the North China Craton and the north margin orogen of the North China Plate. This area serves as a critical large-scale copper-gold and polymetallic mineral resource base in China, also providing favorable geologic conditions for the enrichment and mineralization of rare metals and REEs. So far, many rare-metal and REE deposits and ore occurrences have been discovered in the Liao-Ji tectonic zone, including two large Nb-Be-Zr-REE deposits (i.e., Lijiapuzi and Pianshishan), two medium-sized Rb-Be-Nb-Ta-REE deposits (i.e., Saima and Gangshan), one small Nb-Ta-REE deposit (i.e., Shijia), and over 10 rare metal-REE ore occurrences (e.g., Xiaolizi, and Baiqi), suggesting considerable mineralization potential. Most of the deposits in the Liao-Ji tectonic zone are closely associated with alkaline rocks.Extensive field surveys and geochemical studies of the above deposits reveal that the ore-forming rock masses of the Pianshishan, Gangshan, and Lijiapuzi deposits include alkaline granites and pegmatites and those of the Shijia and Saima deposits are quartz syenites and aegirine nepheline syenites, respectively. The Pianshishan (67±2.2 Ma) and Gangshan (110±1.2 Ma) deposits were formed during the Yanshanian, the Shijia (226.3±2.4 Ma) and Saima (224.4±6.1 Ma) deposits originated from the Late Indosinian magmatism, while the formation of the Lijiapuzi deposit (2501±11 Ma) was associated with the Lvliang Movement. Therefore, the study area underwent three stages of regional rare-metal and REE mineralizations: the Late Yanshanian (Mesozoic), Late Indosinian (Mesozoic), and Proterozoic Lvliangian mineralizations. The petrogeochemical analysis indicates that the ore-forming rock masses of several typical deposits all belong to the metaluminous, alkaline - calc-alkaline, and tholeiitic basalt series, sharing similarities with the elemental geochemical characteristics of intraplate rift rock series and rocks in an extensional environment under plate subduction. The rare-metal and REE mineralizations in the study area were primarily governed by the evolution and crystallization differentiation of alkaline magmas. Given that the alkaline magmatic rocks were all formed by crust-mantle contamination, this study posits that the enrichment and mineralization processes of rare metals and REEs in the Liao-Ji tectonic zone are intimately associated with the highly evolved alkaline magmas. Under the action of water and volatile constituents, magmas underwent intense fractional crystallization, leading to the migration and accumulation of ore-forming elements. With changes in ore-forming conditions such as temperature and pressure, ore-bearing fluids became enriched and mineralized in the late stage of magmatism with the crystallization of primary rock-forming minerals.

The southwestern region of China is tectonically situated within the Tethyan tectonic domain, with the eastern part comprising the Upper Yangtze Block, while the western orogenic belt forms the main part of the Tibetan Plateau. This belt was formed by the subduction of the Paleo-Tethys Ocean and subsequent arc-continent collision, and was later further modified by the India-Asia collision, resulting in complex geological structures such as the Hengduan Mountains. The lithostratigraphy in this region can be divided into six independent units. In terms of mineralization, the area encompasses two first-order metallogenic domains: the Tethyan-Himalayan and the Circum-Pacific. This study synthesizes extensive previous research to systematically investigate representative rare earth element (REE) deposits (e.g., Muchuan and Maoniuping in Sichuan; the Xinhua deposit in Guizhou; the Lincang deposit in Yunnan). Through comparative analysis of regional tectonic-metallogenic settings, we demonstrate that REE distribution in Southwest China is fundamentally controlled by Tethyan tectonic evolution: sedimentary-weathered types dominate in the east, while orogenic magmatism-related types prevail in the west. These findings reveal critical metallogenic patterns, establishing a foundation for cross-regional resource assessment and exploration targeting. The region hosts 32 identified REE occurrences, predominantly light REE (LREE)-enriched, genetically classified as endogenic, exogenic, and metamorphic deposit types. Metallogenic epochs include Precambrian, Paleozoic, and Mesozoic-Cenozoic periods, with the latter being most REE-relevant. Six prospective exploration areas are delineated: Mianning-Dechang, Weining-Zhijin, Long’an, Simao Adebo, Shuiqiao, and the eastern Yunnan-western Guizhou sedimentary-type district. Notably, the discovery of paleo-weathering crust-sedimentary-clay type REE deposits in eastern Yunnan-western Guizhou significantly expands regional exploration potential, opening new avenues for future resource development.

The Central Asian Orogenic Belt (CAOB), one of the world’s largest orogens, extending from the Ural Mountains in the west to the Russian and the Chinese Far East, is the result of long-lived multi-stage tectonic evolution, including Proterozoic to Paleozoic accretion and collision, Mesozoic intracontinental modification, and Cenozoic rapid deformation and uplift [...]

The properties of ancient magmatic arcs are crucial for understanding the tectonic evolution of the Central Asian Orogenic Belt. The Middle Devonian Kulumudi Formation in the Laofengkou area of West Junggar lacks accurate chronological data constraints, which hampers the knowledge of the nature of the Late Paleozoic magmatic arcs in the West Junggar and circum-Balkhash areas. In this contribution, samples of pyroclastic rocks and sedimentary rocks were collected from the volcano–sedimentary strata of the Kulumudi Formation. Petrography, zircon U-Pb-Hf isotopic analysis and whole-rock geochemistry were carried out to constrain the age and the tectonic setting of the Kulumudi Formation. The zircon U-Pb age of the lithic crystal tuff from the Kulumudi Formation on the northeast side of the Alemale Mountains was 386 ± 2 Ma, accurately indicating that this rock unit formed during the Middle Devonian. However, the fine sandstone near the Huojierte Mongolian Township, originally assigned as the “Kulumudi Formation”, yielded a maximum depositional age of 341 ± 3 Ma. Combined with the stratigraphic contact, this rock unit was redefined to belong to the Lower Carboniferous Jiangbasitao Formation. According to the whole-rock geochemistry study, the lithic crystal tuff of the Kulumudi Formation was characterized as medium potassium–calc–alkaline series rock, which is relatively enriched in light rare earth elements and large ion lithophile elements (i.e., Rb, Ba, K) and depleted in high-field-strength elements (i.e., Nb, Ta, Ti), showing similar geochemical characteristics to the volcanic arc rocks. By contrast, the fine sandstone from the Jiangbasitao Formation had Al2O3/SiO2 (0.25–0.29) and K2O/Na2O (1.29–1.72) ratios close to those derived from the continental arc and active continental margin and was characterized as part of the continental arc field in the La-Th-Sc and Th-Sc-Zr/10 tectonic discrimination diagrams. Zircon Hf isotope analysis showed that the εHf(t) values of the Kulumudi Formation were +5.6–+12.8, and those of the Jiangbasitao Formation were +11.43–+15.48, both of which show highly positive juvenile characteristics. The above data indicate that the Kulumudi Formation and Jiangbasitao Formation both formed in a juvenile arc setting with ocean–continent subduction. Combined with the previous work, it was concluded that the southward subduction of the ocean basin represented by the Darbut–Karamay ophiolitic mélanges beneath the newly accreted arc crustal segments produced a juvenile arc with positive Hf isotope characteristics.

This paper is the result of mineral exploration engineering.[Objective]The global rhenium resources are unevenly distributed. Chile accounts for more than half of the total global rhenium resources, mainly from porphyry copper deposits. The type of rhenium deposit is closely related to its occurrence state. Since most of the rhenium ore is associated with other minerals, the classification of rhenium deposits has not yet formed a unified standard,which can not provide a basis for ore prospecting. Therefore, it is urgent to carry out relevant research. [Methods]In this paper, from the perspective of global occurrence of rhenium deposits, ore types and other aspects, the enrichment and mineralization rules and deposit types of existing typical rhenium deposits are systematically sorted out and summarized, in order to provide ideas for the exploration and development of this type of deposits. [Results]Rhenium deposits are divided into four types in this paper: rhenium in porphyry copper deposits, rhenium in sedimentary-type strata-bound copper deposits, rhenium in sandstone-type uranium deposits, and rhenium in skarn deposits. Among them, rhenium in porphyry deposits has the highest grade and largest reserves. In terms of metallogenic characteristics, the Yanshanian period is the most developed for rhenium mineralization, followed by the Himalayan, Indosinian, and Caledonian periods. Large associated rhenium deposits mainly developed in the Caledonian, Indosinian,Yanshanian and Himalayas. In terms of rhenium exploration, more than half of the proven rhenium reserves are from Chile, and the remaining major countries are the United States, Russia, Kazakhstan and Armenia in order. Regarding the development of rhenium ore, rhenium ore is likely to exist in porphyry copper deposits formed in a continental arc environment, and many countries have begun to recover rhenium from porphyry copper deposits. [Conclusions]As an emerging resource, rhenium ore will play an active role in the implementation of energy saving, emission reduction, and carbon neutrality in the future. The exploration of independent rhenium deposits and the genetic mechanism of copper-molybdenum-rhenium associated deposits should be strengthened, and the secondary development and utilization of old mines should be emphasized.

The Daheishan supergiant porphyry molybdenum deposit (also referred to as the Daheishan deposit) is the second largest molybdenum deposit in Asia and ranks fifth among the top seven molybdenum deposits globally with total molybdenum reserves of 1.65 billion tons, an average molybdenum ore grade of 0.081%, and molybdenum resources of 1.09 million tons. The main ore body is housed in the granodiorite porphyry plutons and their surrounding inequigranular granodiorite plutons, with high-grade ores largely located in the ore-bearing granodiorite porphyries in the middle-upper part of the porphyry plutons. Specifically, it appears as an ore pipe with a large upper part and a small lower part, measuring about 1700 m in length and width, extending for about 500 m vertically, and covering an area of 2.3 km(2). Mineralogically, the main ore body consists of molybdenite, chalcopyrite, and sphalerite horizontally from its center outward and exhibits molybdenite, azurite, and pyrite vertically from top to bottom. The primary ore minerals include pyrite and molybdenite, and the secondary ore minerals include sphalerite, chalcopyrite, tetrahedrite, and scheelite, with average grades of molybdenum, copper, sulfur, gallium, and rhenium being 0.081%, 0.033%, 1.67%, 0.001%, and 0.0012%, respectively. The ore-forming fluids of the Daheishan deposit originated as the CO2-H2O-NaCl multiphase magmatic fluid system, rich in CO2 and bearing minor amounts of CH4, N-2, and H2S, and later mixed with meteoric precipitation. In various mineralization stages, the ore-forming fluids had homogenization temperatures of > 420 degrees C-400 degrees C, 360 degrees C-350 degrees C, 340 degrees C-230 degrees C, 220 degrees C-210 degrees C, and 180 degrees C-160 degrees C and salinities of > 41.05%-9.8% NaCleqv, 38.16%-4.48% NaCleqv, 35.78%-4.49% NaCleqv, 7.43% NaCleqv, and 7.8%-9.5% NaCleqv, respectively. The mineralization of the Daheishan deposit occurred at 186-167 Ma. The granites closely related to the mineralization include granodiorites (granodiorite porphyries) and monzogranites (monzogranite porphyries), which were mineralized after magmatic evolution (189-167 Ma). Moreover, these mineralization-related granites exhibit low initial strontium content and high initial neodymium content, indicating that these granites underwent crust-mantle mixing. The Daheishan deposit formed during the Early-Middle Jurassic, during which basaltic magma underplating induced the lower-crust melting, leading to the formation of magma chambers. After the fractional crystallization of magmas, ore-bearing fluids formed. As the temperature and pressure decreased, the ore-bearing fluids boiled drops while ascending, leading to massive unloading of metal elements. Consequently, brecciated and veinlet-disseminated ore bodies formed.(c) 2023 China Geology Editorial Office.

The Daxiyingzi Rb-Be deposit in Fuxin City of Liaoning Province is newly discovered in the northern margin of North China Craton,belonging to the granite-pegmatite type rare metal deposit,mainly composed of biotite granite,albite granite and amazonite granite pegmatite. The ore minerals containing Rb and Be are mainly amazonite and beryl,which are hosted in amazonite granite pegmatite. The metallogenic age of the deposit is about 223 Ma. The geochemical characteristics indicate that the granite is of highly fractioned I-type,which originated from the high-temperature partial melting of Meso-Neoproterozoic basement, with injection of mantle-derived magma. The peraluminous magmatic polymetallic deposit was formed in the orogenic belt setting. Its discovery provides a new direction for mineral exploration in the northern margin of North China Craton.

To ascertain the Early-to-Middle Jurassic tectonic setting in the central Great Xing’an Range, this study investigated the Early and Middle Jurassic granitoids exposed in the Chaihe area in the central Great Xing’an Range based on isotopic chronology and petrogeochemistry. The results of this study show that the Early and Middle Jurassic granitoids have emplacement ages of 179–172 Ma. Moreover, the Early and Middle Jurassic granitoids are high-K calc-alkaline unfractionated I-type granitoids and high-K calc-alkaline fractionated I-type granitoids, respectively. The magma sources of the Early and Middle Jurassic granitoids both originated from the partial melting of newly accreted lower crustal basaltic rocks. Meanwhile, the Middle Jurassic magma sources were mixed with mantle-derived materials or ocean-floor sediments formed by the dehydration and metasomatism of subducted slabs. The Early and Middle Jurassic granitoids in the study area were formed in the subduction environment of the oceanic crust, in which the Mongol-Okhotsk oceanic plate was subducted southward beneath the Eerguna and Xing’an blocks. Moreover, the Siberian plate began to collide and converge with northeast China during the Middle Jurassic.

The Saima alkaline rock-hosted niobium–tantalum deposit (hereafter referred to as the Saima Deposit) is situated in the Liaodong Peninsula, which constitutes the eastern segment of the northern margin of the North China Craton. The rock types of the Saima Deposit include phonolite, nepheline syenite, and aegirine nepheline syenite, which hosts niobium–tantalum ore bodies. In this study, the primary niobium-bearing minerals identified include loparite, betafite, and fersmite. The Saima pluton is characterized as a potassium-rich, low-sodium, and peraluminous alkaline pluton. Trace element characteristics reveal that the metallization-associated syenite is enriched in large-ion lithophile elements (LILEs) such as K and Rb but is relatively depleted in high-field strength elements (HFSEs). As indicated by the rare earth element (REE) profile, the Saima pluton exhibits a high total REE content (∑REE), dominance of light REEs (LREEs), and scarcity of heavy REEs (HREEs). The Sr-Nd-Pd isotopic data suggest that aegirine nepheline syenite and nepheline syenite share consistent isotopic signatures, indicating a common origin. The Saima alkaline pluton displays elevated ISr values ranging from 0.70712 to 0.70832 coupled with low εNd(t) values between −12.84 and −11.86 and two-stage model ages (tDM2) from 1967 to 2047 Ma. These findings indicate that the metallogenic materials for the Saima Deposit derive from both an enriched mantle source and some crustal components. The lithium (Li) isotopic fractionation observed during the genesis of the Saima pluton could be attributed to the differential diffusion rates of 6Li and 7Li under non-equilibrium fluid–rock interactions.

This paper is the result of mineral exploration engineering.[Objective] As the lightest alkaline earth metal, beryllium has become an excellent functional and structural material. Due to its special physical and chemical characteristics such as density, stiffness and melting point, it has great scientific and economic value for researching the genetic mechanism, exploration and development. [Methods] In this paper, the characteristics, genesis and exploration technology of typical beryllium deposits in the domestic and overseas are systematically sorted out and summarized. The metallogenic rules are summarized from time and space scales by means of similarity and analogy, and the exploration, development and utilization suggestions are also put forward. [Results] Beryllium deposits can be divided into endogenous and exogenous types.Exogenous beryllium deposits can be subdivided into different deposit types related to weathering or metamorphism. According to the alkali-aluminum properties of magma system, endogenous beryllium deposits can be subdivided into peraluminous,metaluminous and peralkaline metallogenic systems. According to the fluid evolution stage, it can be subdivided into magma type,pegmatite type and magma hydrothermal type. [Conclusions] From the perspective of metallogenic age, the beryllium mineralization in either peraluminous, metaluminous or peralkaline systems is concentrated in the Mesozoic. Yanshanian is the main metallogenic period of beryllium deposits. From the perspective of metallogenic structure background, the magma type is often produced in post-collision environments, the magmatic hydrothermal type is produced on the continental margin, and the pegmatite type is basically produced in the orogenic belt. Beryllium is one of the new materials, which will play an important role in energy conservation, emission reduction and carbon neutralization in the future. Research on comprehensive utilization and recovery technology of beryllium deposits should be strengthened.

The reserves of the Duobaoshan porphyry Cu-Au-Mo-Ag deposit (also referred to as the Duobaoshan porphyry Cu deposit) ranks first among the copper deposits in China and 33rd among the porphyry copper deposits in the world. It has proven resources of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) of 2.28x10(6) t, 80x10(3) t, 73 t, and 1046 t, respectively. The major characteristics of the Duobaoshan porphyry Cu deposit are as follows. It is located in a zone sandwiched by the Siberian, North China, and paleo-Pacific plates in an island arc tectonic setting and was formed by the Paleozoic mineralization and the Mesozoic mineralization induced by superposition and transformation. The metallogenic porphyries are the Middle Hercynian granodiorite porphyries. The alterations of surrounding rocks are distributed in a ring form. With silicified porphyries at the center, the alteration zones of K-feldspar, biotite, sericite, and propylite occur from inside to outside. This deposit is composed of 215 ore bodies (including 14 major ore bodies) in four mineralized zones. Ore body No. X in the No. 3 mineralized zone has the largest resource reserves, accounting for more than 78% of the total reserves of the deposit. Major ore components include Cu, Mo, Au, Ag, Se, and Ga, which have an average content of 0.46%, 0.015%, 0.16 g/t, 1.22 g/t, 0.0003%, and 0.001% -0.003%, respectively. The ore minerals of this deposit primarily include pyrite, chalcopyrite, bornite, and molybdenite, followed by magnetite, hematite, rutile, gelenite, and sphalerite. The ore-forming fluids of this deposit were magmatic water in the early metallogenic stage and then the mixture of meteoric water and magmatic water at the late metallogenic stage. The ore-forming fluids experienced three stages. The ore-forming fluids of stage I had a hydrochemical type of H2O-CO2-NaCl, an ore-forming temperature of 375 -650 degrees C, and ore-forming pressure of 110-160 MPa. The ore-forming fluids of stage II had a hydrochemical type of H2O-CO2-NaCl, an ore-forming temperature of 310 -350 degrees C, and ore-forming pressure of 58-80 MPa. The ore-forming fluids of stage III had a hydrochemical type of NaCl-H2O, an ore-forming temperature of 210 -290 degrees C, and ore-forming pressure of 5-12 MPa. The Cu-Au-Mo-Ag mineralization mainly occurred at stages I and II, with the ore-forming materials having a mixed crust-mantle source. The Duobaoshan porphyry Cu deposit was formed in the initial subduction environment of the Paleo-Asian Ocean Plate during the Early Ordovician. Then, due to the closure of the Mongol-Okhotsk Ocean and the subduction and compression of the Paleo-Pacific Ocean, a composite orogenic metallogenic model of the deposit was formed. In other words, it is a porphyry -epithermal copper-gold polymetallic mineralization system of composite orogeny consisting of Paleozoic island arcs and Mesozoic orogeny and extension. (c) 2023 China Geology Editorial Office.

古亚洲洋不是西伯利亚陆台和华北地台间的一个简单洋盆,而是在不同时间、不同地区打开和封闭的多个大小不一的洋盆复杂活动(包括远距离运移)的综合体.其北部洋盆起始于新元古代末—寒武纪初(573～522 Ma)冈瓦纳古陆裂解形成的寒武纪洋盆.寒武纪末—奥陶纪初(510～480 Ma),冈瓦纳古陆裂解的碎块、寒武纪洋壳碎块和陆缘过渡壳碎块相互碰撞、联合形成原中亚-蒙古古陆.奥陶纪时,原中亚-蒙古古陆南边形成活动陆缘,志留纪形成稳定大陆.泥盆纪初原中亚-蒙古古陆裂解,裂解的碎块在新形成的泥盆纪洋内沿左旋断裂向北运动,于晚泥盆世末到达西伯利亚陆台南缘,重新联合形成现在的中亚-蒙古古陆.晚古生代时,在现在的中亚-蒙古古陆内发生晚石炭世(318～316 Ma)和早二叠世(295～285 Ma)裂谷岩浆活动,形成双峰式火山岩和碱性花岗岩类.蒙古-鄂霍次克带是西伯利亚古陆和中亚-蒙古古陆之间的泥盆纪洋盆,向东与古太平洋连通,洋盆发展到中晚侏罗世,与古太平洋同时结束,其洋壳移动到西伯利亚陆台边缘受阻而向陆台下俯冲,在陆台南缘形成广泛的陆缘岩浆岩带,从中泥盆世到晚侏罗世都非常活跃.古亚洲洋的南部洋盆始于晚寒武世.此时,华北古陆从冈瓦纳古陆裂解出来,在其北缘形成晚寒武世—早奥陶世的被动陆缘和中奥陶世—早志留世的沟弧盆系.志留纪腕足类生物群的分布表明,华北地台北缘洋盆与塔里木地台北缘、以及川西、云南、东澳大利亚有联系,而与上述的古亚洲洋北部洋盆没有关连,两洋盆之间有松嫩-图兰地块间隔.晚志留世—早泥盆世,华北地台北部发生弧-陆碰撞运动,泥盆纪时,在松嫩地块南缘形成陆缘火山岩带,晚二叠世—早三叠世华北地台与松嫩地块碰撞,至此古亚洲洋盆封闭.古亚洲洋的南、北洋盆最后的褶皱构造,以及与塔里木地台之间发生的直接关系,很可能是后期的构造运动所造成的.

[研究目的]石墨已成为新兴技术产业的重要原材料,也是未来高新技术发展的重要关键性矿产资源.中国既是石墨资源大国,也是生产消费大国,摸清石墨矿产资源分布现状,总结不同成因类型石墨矿床地质特征及成矿规律对保障石墨有效供给具有重要意义.[研究方法]搜集已公开发表或出版的石墨矿产资料,对石墨矿床地质特征、物质来源及成因等内容进行系统总结.[研究结果]石墨矿集区主要分布于东亚—南亚、东非、东欧—中欧、北美洲、南美洲和大洋洲等地,各矿集区资源禀赋、矿床成因及成矿地质特征各具特色.中国和东非的马达加斯加、莫桑比克、坦桑尼亚等国,近几年找矿成果显著,探获多处资源量达亿t级的石墨矿床;中国、莫桑比克、巴西为石墨矿主要生产国,2020年3国石墨产量约占总产量的80％.[结论]重新划分为区域变质型、热液型、岩浆型和接触变质型四大类石墨矿床,其中区域变质型、接触变质型、岩浆热液型及深成岩型石墨矿的碳质来源主要为有机质,而变质热液型和火成碳酸岩型石墨矿则以幔源岩浆碳为主.