The Hongling skarn Fe-Pb-Zn deposit is situated in the Lindong district of eastern Inner Mongolia, southern Great Hinggan Range. Previous investigations have established that the metallogenic fluid and ore-forming material at Hongling originated from the magmatic system, with mineralization temporally coinciding with the early Cretaceous granitic emplacement (ca. 142-143 Ma). Petrogenetic studies further suggest that the Hongling granitoids share comparable magmatic origins and evolutionary pathways with regional contemporaneous intrusions. In this contribution, we integrate new zircon U-Pb geochronology, whole-rock geochemistry, and Sr-Nd-Hf-S-Pb isotopic analyses of porphyritic granitoids and associated sulfides with existing regional datasets to: (1) constrain the magmatic evolution of Hongling intrusives; (2) discriminate between mineralized and barren intrusion characteristics; and (3) elucidate metallogenic processes. In situ sulfur (delta 34S =-2.8 %o to +1.1 %o) and lead (206Pb/204Pb = 18.292 to 18.303) isotopic signatures from ore minerals demonstrate a predominant magmatic derivation..The porphyritic granitoids exhibit transitional Sr-Nd-Hf isotopic compositions ((87Sr/86Sr)i= 0.7065-0.7091, epsilon Nd(t) =-1.25 to +0.69, and epsilon Hf(t) = +0.12 to +8.39), consistent with partial melting of juvenile lower crustal sources. Comparative analysis with regional coeval plutons reveals that the Lindong mineralized intrusions underwent crystal-melt segregation processes, with the Hongling porphyritic phase representing interstitial melts extracted from crystal-rich mush zones.. Subsequent reactivation of these segregated melts facilitated efficient extraction and concentration of ore-forming fluids, ultimately leading to FePb-Zn mineralization through fluid-rock interaction in skarn systems.

The early to late Cretaceous granitoids of the Tengchong terrane offer key insights into the tectonic evolution of the Meso-Tethys and Neo-Tethys Oceans and associated polymetallic mineralization. This study employs petrological, geochemical, and isotopic analyses (Sr-Nd, zircon U-Pb, Lu-Hf) to investigate the Diantan, Guyong, and Xiaolonghe plutons and their tectonic evolution. Zircon U-Pb dating reveals ages of 116.5 Ma for the Diantan granite porphyry, 71.8 Ma for the Guyong biotite granite, 76.5 Ma for the Xiaolonghe monzogranite, and 66.4 Ma for the Xiaolonghe granodiorite. Geochemical data show that the Early Cretaceous granites are S-type, while the Late Cretaceous granites are A-type, reflecting a transition from syn-collisional to post-collisional extension. Negative zircon epsilon Hf(t) values (-3.1 to-14.9) and two-stage model ages (TDM2 = 1.17-2.03 Ga) indicate incorporation of Mesoproterozoic and Paleoproterozoic crustal material. Sr isotope ratios (initial 87Sr/86Sr(i) values ranging from 0.709662 to 0.725917) suggest formation via melting of heterogeneous sources, including igneous and metamorphosed sedimentary rocks. The significant contribution of remelted tin-rich strata and multi-stage fractional crystallization explains variations in ore-bearing properties of the tin-bearing granites at Xiaolonghe and Lailishan. These findings highlight the strong tin mineralization potential of the Tengchong-Lianghe region, driven by multi-phase magmatism and substantial deep-seated tin resources.

The supergiant Shuangjianzishan (SJZ) Ag-Pb-Zn deposit is in the southern segment of the Great Hinggan Range (SGHR), northeast China. Previous studies suggest the ore-forming material and fluid originated from the magmatic system, and the mineralization age was consistent with the diagenetic age. However, the relationship between granitic magmatism and mineralization is still unclear in the SJZ. In this study, C-H-O-He-Ar and in-situ S-Pb isotope analyses were conducted to determine the sources of ore-forming fluids and metals, which were combined with geochemistry data of SJZ granitoids from previous studies to constrain the relationship between the magmatism and the mineralization. The C-H-O-He-Ar-S-Pb isotopic compositions suggested the SJZ ore-forming material and fluids were derived from a magmatic source, which has mixed a small amount of mantle-derived materials. In addition, the disseminated sulfide from the syenogranite has comparable S-Pb isotopic composition with the sulfide minerals from ore veins, suggesting that the generation of the SJZ ore-forming fluids has a close relationship with the syenogranite magmatism. Combining with the geochemical characters of the syenogranite, the authors proposed that the mantle-derived fingerprint of the SJZ ore-forming fluid might be caused by the parent magma of the syenogranite, which was derived from partial melting of the juvenile lower crust, and underwent the residual melts segregated from a crystal mush in the shallow magma reservoir. The extraction of the syenogranite parent magma further concentrated the fertilized fluids, which was crucial to mineralization of the SJZ Ag-Pb-Zn deposit.

在大量典型矿床剖析的基础上,以矿物学、岩石学、矿床学、构造地质学、地球化学等基础理论为指导,以大量实地观察和实验数据为支撑,通过总结矿山深部和外围找矿实践和典型矿床研究成果,按照成矿作用内因和外因相结合的辩证思维,成矿作用时间、空间、物质能量相统一的综合思维,以及元素地球化学分类和找矿预测矿床分类的比较思维,提出成矿地质体、成矿构造和成矿结构面、成矿作用特征标志等概念.成矿地质体是形成矿床主要矿产、决定主成矿阶段空间位置的成矿地质作用的实物载体,划分为沉积作用、火山作用、岩浆作用、变质作用和大型变形作用形成的 5 类成矿地质体.成矿结构面是赋存矿体的各类界面,包括构造界面、岩性界面、物理化学转换界面;成矿作用特征标志是能够直接指示矿体赋存位置和对找矿预测具有特殊意义的标志.依据成矿地质作用对中国主要矿床类型进行梳理划分,归纳总结了主要矿床类型的地质特征,构建了反映矿体赋存位置的成矿地质体-成矿结构面-成矿作用特征标志"三位一体"找矿预测地质模型.在此基础上,提出勘查区找矿预测的工作方法,对矿床学研究、找矿预测、矿产勘查工作具有重要的指导意义.

The microgranular enclaves (MEs) and their host granitoids contain vital information on the genesis and evolution of the magma, especially for those which have close relationship with mineralization, yet remains a hot debate on their origin. Here, we investigate the MEs and their host granitoids in the Shuangjianzishan (SJZ) deposits, southern Great Hinggan Range, NE China, using ziron U–Pb dating and Hf isotopes, along with a systematic analysis of whole‐rock geochemical and Sr‐Nd isotopic compositions. The SJZ MEs mainly consist of monzonites and quartz monzonites, and the SJZ granitoids comprise a suite of fine‐grained syenogranites and coarse‐grained monzogranites. The zircon U–Pb dating results suggest that the SJZ granitoids and the SJZ MEs were emplaced at approximately 143–141 Ma. Geochemical features and isotopic compositions of the SJZ granitoids indicate that they are mainly generated by partial melting of juvenile lower‐crustal basaltic rocks. The fine‐grained syenogranites and the coarse‐grained monzogranites have a gradual contact relationship, similar crystallization age, Sr‐, Nd‐, and Hf‐isotopic compositions, suggesting that they were derived from a similar silicic magma reservoir. According to the geochemical compositions and petrographic characteristics (aggregates of coarse‐grained euhedral plagioclase crystals) of the SJZ granitoids, we infer that the monzogranites (SiO 2 = 69.24–74.95 wt%) are regarded as the residual cumulate and the fine‐grained syenogranites (SiO 2 = 74.83–77.97 wt%) are high silica melts segregated from a crystal mush. The SJZ MEs are characterised by low SiO 2 (50.03–64.20 wt%) and MgO (1.08–2.63 wt%) contents, high P 2 O 5 contents and contain acicular apatite, which are consistent with the products of intermediate magma. Combining with the MEs have comparable crystallization age, mineral assemblage, whole‐rock Sr‐Nd and zircon Hf‐isotopic compositions with their host granitoids, implying the MEs were autoliths related to their host monzogranites. Collectively, we infer that the SJZ MEs were generated by the rapid cooling and crystallization of the hot ascending intermediate magmas contacted with the cooler wall rocks, then those sub‐solid fine‐grained crystal‐rich margins were fragmented and injected into the progressive evolved mush chamber, leading to the extraction and upward percolation of high silicic melts from the compacting crystal‐rich mush in the shallow crust.

文章简要报道了中国东部、美国西部成矿规律对比与资源评价技术研究的思路、方法和主要认识;环太平洋成矿带是世界上最重要的、具有全球意义的巨型成矿带之一,涉及的国家多、矿产资源丰富;深入开展环太平洋成矿带对比研究,对于更好地把握环太平洋地区战略资源、"有的放矢"地在相关国家搞好资源外交、探索"双循环"有效途径、地学创新等具有重要意义和借鉴.

在当前逆全球化及贸易保护主义抬头趋势下,对中老铁路经济廊带各优势自然资源进行综合区划研究对我国具有重大战略意义.以区域成矿理论、规律及矿点分布、卫星影像、地形地貌、土壤理化性质、气候资料、路网车站等数据为基础,采用叠置分析、网络分析等空间分析方法对廊带内的矿产、林木和土地资源进行评价并考虑时间、距离成本效应进行综合区划研究.结果显示:中老边境丰沙里、南塔省是林木资源优先开发区,乌多姆赛东部为后备开发区;沙耶武里的狭长河谷地带是潜在基础设施建设重点区;乌多姆塞南部及万象北部为矿产资源优先开发区.以中老铁路为依托的综合区划研究可为我国自然资源的贸易进口运输及境外战略布局提供支撑.

The China Geological Survey (CGS) is affiliated to the Ministry of Natural Resources of the People's Republic of China, and is responsible for the unified deployment, organization and implementation of basic, public and strategic geological surveying and mineral exploration, providing basic geological data and information for economic and social development, and responding to public demands. Over the past 20 years, the CGS has been focusing on the national key development strategies and undertaking geological surveys to support the nation's resources and energy security, regional economic development, disaster prevention and mitigation, poverty alleviation, and other related undertakings. Specifically, the CGS has been playing a role in the following areas: assessment of mineral resources, energy resources, urban geology and geo-environment, as well as offering update and application of geodata for public and several other services.

In support of IGCP 259 (International Geochemical Mapping) and IGCP 360 (Global Geochemical Baselines), a pioneer project designed to test the feasibility of wide-spaced global geochemical mapping: "Environmental Geochemical Monitoring Networks and Dynamic Geochemical Maps in China" (EGMON), was launched in 1992. The aims of this project are to study the suitability and feasibility of floodplain sediment as a global sampling medium, to develop the methodologies of wide-spaced sampling of such sediment and to study the broad geochemical patterns in China in order to obtain an overall assessment of the country's mineral resource potential and an overview of its environment. 529 floodplain sediment samples with an average density of 1 sample per 15000 km were taken all over China. Geochemical patterns revealed by wide-spaced floodplain sediment sampling show great coincidence with RGNR (Regional Geochemistry-National Reconnaissance, China's national geochemical mapping program) and SEBV (Soil Environmental Background Values in China) broad geochemical patterns. Geochemical maps produced by data from wide-spaced floodplain sediment sampling show that there is an important Pt-Pd geochemical province in Southwestern of China. Changes in Hg and P distribution patterns in surface and deep samples are noted; Hg and P pollution is occurring over large areas in China. An area of soil vulnerability is identified in Southeastern China. A chemical time bomb of aluminum similar to the one in central Europe in Southeastern China is predicted preliminarily. Large scale forest dieback may occur within these areas in the future.

The Huoshaoyun carbonate-hosted nonsulfide Zn deposit, in the Sanjiang-Tethys metallogenic belt of west China, is a newly discovered world-class deposit. Two ore bodies occur in the Longshan Formation limestone, in which the ore textures are mainly developed as laminated, banded, and brecciated. The metal minerals of the Huoshaoyun deposit are dominated by smithsonite and cerussite, with subordinate amounts of galena and siderite. Ore mineralization of this deposit is distinguished into three stages: sulfide stage, oxidation stage, and post-oxidation stage. Unlike most supergene Zn-Pb deposits, the Huoshaoyun orebody shows comparable ore grades for both Pb and Zn with an inverse supergene chemical zoning. Zinc is most abundant at the top of the deposit, whereas lead increases with depth. These two elements have different mobilities in solution, which implies that the primary source of zinc in the Huoshaoyun nonsulfide mineralization was originally located not far from the primary galena mineralization, the remnants of which are present in situ. Supergene zinc mineralization was derived from the dissolution of primary sphalerite hosted in the now-eroded rocks above the Huoshaoyun mine site. Zinc-rich solution migrated through the sedimentary host rocks, precipitated Zn minerals in pore spaces, and replaced detrital and hydrothermal alteration minerals.

New zircon U–Pb age data, Hf isotopes, whole‐rock major and trace elements, and Sr–Nd isotopic data for Early–Middle Triassic intrusive rocks from the Jiawula and Tsagenbulagen area in the southern part of the Erguna Massif provide valuable constraints on the southward subduction of the Mongolia–Okhostk Ocean lithosphere. The Jiawula–Tsagenbulagen granitoids mainly consist of granodiorite, quartz monzonite, and biotite granite. These granitoids, long believed to be mainly Late Jurassic–Early Cretaceous (ca. 150–139 Ma) and minor Permian (ca. 278 Ma and 254–253 Ma), are newly found to contain a latest Early Triassic to Middle Triassic generation (zircon U–Pb age: ca. 248–244 Ma). Geochemically, the Early to Middle Triassic granitoids are characterized by high SiO2 (74–77 wt.%) and Al2O3 (12.2–15.95 wt.%), low Mg# values (12.98–37.32), and variable Na2O/K2O ratios (0.62–1.75). They are metaluminous to peraluminous and belong to the high‐K calc‐alkaline series. Moreover, they show enrichment in light rare earth elements and large‐ion lithophile elements and depletion in heavy rare earth elements and high‐field‐strength elements (e.g., Nb, Ta, and Ti). They have an increased amount of SiO2/Al2O3 but lower V/Th ratios and negative correlations between V/Th and SiO2/Al2O3 ratios, indicating that the magmas experienced various degrees of biotite and/or plagioclase fractional crystallization. Their whole‐rock εNd(t) and zircon εHf(t) values ranged from +1.07 to +4.15 and from +0.5 to +2.9, respectively, indicating that the primary magmas were probably generated by partial melting of juvenile crustal material with the help of mantle‐derived mafic magmas. These magmas subsequently underwent fractional crystallization, magma mixing, and a small amount of crustal contamination during their emplacement. The geochemical characteristics of these Early–Middle Triassic intrusive rocks have affinities with intrusive rocks from active continental margin settings. Therefore, we conclude that the Early–Middle Triassic magmatism in the Erguna Massif was generated within an Andean‐type arc setting related to the southwards subduction of the Mongol–Okhotsk oceanic plate beneath the Erguna Massif. We summarized previous age data of the Early to Late Triassic magmatic rocks from Erguna and Central Mongolia and identified arc setting granites and post‐orogenic granites. Thus, a tectonic evolutionary model was proposed for the geological observations in the Erguna and Central Mongolia massifs, involving the Triassic continuous southward subduction in the Erguna Massif and the Late Triassic slab‐rollback and back‐arc basin extension in the south‐eastern Central Mongolia Massif.

The Dayishan orefield in the central Nanling belt is one of the most important Sn districts in South China. Within this district, there are more than seven medium-to-large Sn, Sn-Cu and Pb-Zn-Sn deposits. The mineralization is associated with altered granites and greisen-quartz veins, both of which occur in the inner part of the Dayishan granite batholith. Cassiterite is the principal ore mineral, accompanied by subordinate molybdenite. Cassiterite separates from altered and mineralized granite and greisen-quartz veins have concordia ages of 156.5 +/- 2.8 Ma (MSWD = 3.1) and 158.0 +/- 1.8 Ma (MSWD = 1.4), respectively. Molybdenite separates from molybdenitequartz veins that crosscut the greisen alteration have a Re center dot Os isochron age of 157.9 +/- 7.7 Ma (MSWD = 26), whereas zircon separates from the porphyry monzogranite have a U-Pb age of 156.3 +/- 1.2 Ma. These ages are identical within the analytical error and, together with the field relationships, provide tight constraints on the Sn mineralization at around 156 Ma. Rhenium contents of the molybdenite suggests that the ore-forming materials were derived from a crustal source, whereas S and Pb isotopic data point to mixed sources. We suggest that the Maozaishan deposit was formed by intrusion of the related pluton, and occurred in the Late Jurassic during a period of lithospheric thinning and crustal extension of the South China Block.

Continental China has moved dextral Eastward since Cenozoic time, driven by the collision of the Indian with the Eurasian plate. Evidence for this comes from landscape evolution, the distribution of earthquake epicenters, Cenozoic sedimentary and volcanic rocks, and the measurement of GPS velocity vectors, the distribution of crustal stress, paleomagnetic data, and deep mantle structure, among others. This movement commenced around 40 Ma, coupled with thickened lithosphere and widespread stress release along strike-slip faults that bound the continental Chinese block. Because of continued Northward subduction of the Indian plate, manifestation of the dextral movement has intensified since 25 Ma. Far-reaching effects include extensive strike-slip movement on the Tan-Lu fault in Eastern China, formation of the Dabie ultrahigh pressure metamorphic terrane, extensive thrust faults in East China, delamination and thickening of the lithosphere of South China, a possible tectonic doubling of the Middle-Lower Yangtze Valley metallogenic belt, and the formation of the Japan, Huanghai (East China), and South China Sea.

The Duocaima Pb-Zn deposit in Tuotuohe area, Qinghai Province is one of the typical deposits of the Cenozoic Pb-Zn metallogenic region in the northern Sanjiang-Tethys. In this paper, in-situ S and Pb isotope data of metallic sulfide in Duocaima deposit is first determine by fs LA-MC-ICPMS method. The results show that the delta S-34(V-CDT) values of metal sulfides range from - 26. 34 parts per thousand similar to 4. 24 parts per thousand, with an average of - 12. 15 parts per thousand, which the sphalerite, galena and pyrite has delta S-34(V-CDT) values ranging from - 10. 30 parts per thousand similar to 3. 52 parts per thousand ( mean = -7. parts per thousand, n = 9) , 26. 34 parts per thousand similar to -11.74 parts per thousand ( mean = 20. 36 parts per thousand, n = 9) and 2.50 parts per thousand to 4.24 parts per thousand, respectively. The widely ranged data suggests the enrichment of the negative sulfur, which may indicate the involvement of organic matter in the mineralization. The delta S-34(V-CDT) value of pyrite developed in the magmatic hydrothermal stage has deep source features, however, the delta S-34(V-CDT) value of galena and sphalerite developed during the depositional hydrothermal stage indicate that there are reduction in the mineralization process. Meanwhile, the incorporation of reducing fluid in the basin formation is necessary, so that the sulfur of Duocaima Pb-Zn deposit has the characteristics of mixed sources. In situ Pb isotopes of galena analyzed by fs LA-MC-ICPMS results are (208)pb/Pb-204 within 18. 866 similar to 18. 929 ( average at 18. 897) , (208)pb/Pb-204 within 15. 674 similar to 15. 689 ( average at 15. 680) , (208)pb/Pb-204 within 39. 052 similar to 39. 174 ( average at 39. 120). The Pb isotopic composition of galena and stratum is consistent with the average lead evolution line in the upper crust, with the characteristics of the upper crust and mantle mixed subduction zone lead, indicating that the ore-forming materials is diverse. Based on Mineral deposits, Mineralogy and isotope data, the S and Pb mainly derived from the surrounding rock, northern Tibetan volcanic rocks, respectively. The mechanism of sedimentation is the mixture of the intrusive stratum magma with the basin fluid.

内蒙古满洲里地区的甲乌拉铅锌银矿区的成岩、成矿事件及其相互关系目前仍有很大争议.文中对矿区内与成矿密切相关的石英斑岩、闪长玢岩开展详细研究.锆石SHRIMP U-Pb年代学研究表明:矿区致矿侵入体之一石英斑岩形成于(129±4.8) Ma,成矿晚(或后)期的闪长玢岩形成于约(124±2.5)Ma;认为铅锌银等成矿作用应发生于(129±4.8)～(124±2.5) Ma,为早白垩世末期.岩石地球化学特征显示石英斑岩具有高硅、高钾、贫钙等特征,TAS图上属于亚碱性系列,硅-铁镁图上属于钙碱系列,硅钾图上属于高钾钙碱系列.轻重稀土分馏明显,具有明显的负铕异常.相对富集大离子亲石元素(LILE),而亏损高场强元素(HFSE),且具有低Sr、高Y等特征.闪长玢岩同样展现出高钾、高铝、贫钙特征,TAS图上属于亚碱性系列,硅铁镁图上属于拉斑系列;轻、重稀土分馏明显,具明显负铕异常,但稀土总量较高;相对富集大离子亲石元素(LILE),亏损高场强元素(HFSE),同具有低Sr、高Y等特征.这些研究结果表明:石英斑岩具有火山弧的特征,主要来源于壳源的熔融;闪长玢岩具有活动大陆边缘弧的特征,主要来源于地幔的熔融,但经历了壳源的混染上述岩浆与甲乌拉的铅锌银矿;推测应为蒙古—鄂霍次克洋由俯冲向陆陆转换阶段产物.

Northeast China has more than 70 deposits occurrences) and experienced complex tectonic evolution history.At present,the understanding about the geodynamic tectonic background for the magmatic and metallogenic events in the Mesozoic period is controversial.Systematically summary show that there are three metallogenic belts in this area,including Great Xing' an Range belt,Xiao Xing' an Range-Zhuang Guangcai Range belt and Xilamulun River belt,and formed in Triassic,early-to mid-Jurassic and late-Jurassic to early-Cretaceous.Based on regional geological data,we suggest that the spatial and temporal distribution of the molybdenum deposits in Northeastern China is mostly constrained by geodynamic background.The molybdenum deposits formed in Triassic could form in collisional orogenic or partial stretching environment after the collision between North China block and Siberia block,which related to the closure of Paleo-Asian Ocean.Early-to mid-Jurassic molybdenum deposits are constrained by the subduction of Paleo-Pacific Ocean block.Late Jurassic to early Cretaceous molybdenum deposits are constrained by Mongolia-Okhotsk Ocean tectonic domain.While their influence failed to cross the east boundary of Liaoning basin and north region of Hebei Province.

In order to discuss the source,character,and the evolution process of the ore-forming fluid of the Xiaoteishan deposit A systematic fluid inclusion study has been carried out on ore-bearing quartz veins and barite samples of the Xiao-tieshan deposit.Results show that there are several types of fluid inclusions including liquid-gaseous inclusion,pure gase-ous inclusion,pure liquid inclusion,and CO2-bearing three phase inclusions.The microthermometric results show that hom-ogenization temperatures and salinities of fluid inclusions in quartz and barite veins from the vein-type orebody at the bot-tom of the Xiaotieshan deposit vary from 174℃ to 452℃ and from 0. 88% to 9. 86% NaCleqv,and from 149℃ to 388℃and from 2. 07%to 12. 16%respectively.In addition,homogenization temperatures and salinities of fluid inclusions of the massive orebody of the Xiaotieshan deposit vary from 178℃to 296℃ and from 1 . 91%to14. 46%NaCleqv respectively.Hy-drogen and oxygen isotope studies show that δ18O and δDV-SMOW values of water in fluid inclusions of the ore-forming quartz vein vary from -1 . 14‰ to 4. 68‰ and from -88. 0‰ to -153. 2‰,respectively.Combining the petrographical features of fluid inclusions and their fluid features,it is inferred that the ore-forming fluid of the Xiaotieshan deposit was the mixture of the magmatic fluid and the heated seawater.

The Tonglushan Cu deposit is situated in a densely populated area and has been mined for since 11 B.C. Pyrite is the sulphfide associated with copper, and it plays an important role in the geo-environmental process. It can change the pH and metals content of groundwater. Stream sediment and water samples were collected and analysed for metals via inductively coupled plasma mass spectrometry (ICP-MS). Results showed that the amounts of metals in underground water are low and significantly lower than the level described in the Drinking Water Standard of the People's Republic of China (DWSC) even though the deposit has been mined for over 3000 years. We can conclude that no severe environmental disaster has occurred in the local area despite thousands of years of mining because Tonglushan Cu deposit is an environmentally friendly skarn and carbonate-replacement deposit with low sulphide and high acid neutralising capacity in wall rock, altered rock, and ore.

The Dahutang tungsten polymetallic ore field is located north of the Nanling W–Sn polymetallic metallogenic belt and south of the Middle–Lower Yangtze River Valley Cu–Mo–Au–Fe porphyry‐skarn belt. It is a newly discovered ore field, and probably represents the largest tungsten mineralization district in the world. The Shimensi deposit is one of the mineral deposits in the Dahutang ore field, and is associated with Yanshanian granites intruding into a Neoproterozoic granodiorite batholith. On the basis of geologic studies, this paper presents new petrographic, microthermometric, laser Raman spectroscopic and hydrogen and oxygen isotopic studies of fluid inclusions from the Shimensi deposit. The results show that there are three types of fluid inclusions in quartz from various mineralization stages: liquid‐rich two‐phase fluid inclusions, vapor‐rich two‐phase fluid inclusions, and three‐phase fluid inclusions containing a solid crystal, with the vast majority being liquid‐rich two‐phase fluid inclusions. In addition, melt and melt‐fluid inclusions were also found in quartz from pegmatoid bodies in the margin of the Yanshanian intrusion. The homogenization temperatures of liquid‐rich two‐phase fluid inclusions in quartz range from 162 to 363°C and salinities are 0.5wt%–9.5wt% NaCl equivalent. From the early to late mineralization stages, with the decreasing of the homogenization temperature, the salinity also shows a decreasing trend. The ore‐forming fluids can be approximated by a NaCl–H2O fluid system, with small amounts of volatile components including CO2, CH4 and N2, as suggested by Laser Raman spectroscopic analyses. The hydrogen and oxygen isotope data show that δDV.SMOW values of bulk fluid inclusions in quartz from various mineralization stages vary from –63.8‰ to –108.4‰, and the δ18OH2O values calculated from the δ18OV‐SMOW values of quartz vary from –2.28‰ to –7.21‰. These H–O isotopic data are interpreted to indicate that the ore‐forming fluids are mainly composed of magmatic water in the early stage, and meteoric water was added and participated in mineralization in the late stage. Integrating the geological characteristics and analytical data, we propose that the ore‐forming fluids of the Shimensi deposit were mainly derived from Yanshanian granitic magma, the evolution of which resulted in highly differentiated melt, as recorded by melt and melt‐fluid inclusions in pegmatoid quartz, and high concentrations of metals in the fluids. Cooling of the ore‐forming fluids and mixing with meteoric water may be the key factors that led to mineralization in the Dahutang tungsten polymetallic ore field.

本文对中亚造山带东段内蒙古迪彦钦阿木地区玄武岩(～260 Ma)开展了岩石学和地球化学的系统研究.元素和Sr-Nd同位素地球化学研究表明,该区玄武岩具有富集LREE和亏损HREE的特征,呈现出明显的Eu正异常,而几乎无Ce异常.微量元素组成表现出富集LILE(如Rb、Th和K)和亏损HFSE(如Nb、Ta、Zr和Hf)的特征.同时,该区玄武岩具有较高的Nb/Ta比值(＞17),较低的初始87Sr/86Sr比值(0.7026～0.7033),以及正的□Nd(t)值(3.6～4.6).综合分析表明,该区玄武岩具有俯冲带火山岩的地球化学特征,其源区主要为亏损的岩石圈地幔,并局部有软流圈物质的加入,但岩浆演化过程中壳源物质混染程度不高.通过元素判别图解及区域地质资料分析,我们推测该区玄武岩的形成与弧后伸展环境下软流圈物质上涌而导致岩石圈地幔的部分熔融有关.因此,古亚洲洋的闭合时限应该不早于该玄武岩的喷发时间(～260 Ma),并且同期存在古亚洲洋板块向北方的西伯利亚或者南蒙古微陆块的俯冲.