The Toudaoqiao niobium-tantalum (Nb-Ta) deposit is the largest magmatic rock-type rare metal deposit discovered in the Great Xing'an Range. The ore body is hosted in alkaline rhyolite, and Nb-Ta primarily hosted by columbite, magnetite-(Nb), and ilmenite-(Nb). In this study, we present U-Pb zircon ages, Hf isotope date, and whole-rock geochemistry to elucidate Toudaoqiao alkaline rhyolite evolution. Magmatic zircon ages suggest the mineralization occurred in the Early Cretaceous. The positive epsilon(Hf)(t) (zircon) values range from 5.50 to 9.61 with T-DM2 of 836-574 Ma, as well as the geochemical characteristics of K2O/Na2O > 1 and Mg-# <<40, indicate that the magma originated from the partial melting of Neoproterozoic-Paleozoic newly accreted potassium-rich intermediate-mafic lower crust. During extension of the Great Xing'an Range in the Early Cretaceous, roll-back of the subducting Paleo-Pacific plate triggered upwelling of asthenosphere mantle material to heat and partially melt the lower crust. The parental magma became highly fractionated by the action of F and other volatiles, resulting in enrichment of Nb-Ta in the residual melt, culminating in precipitation of Nb-Ta minerals. A magma source characterized by significant rare element enrichment is the key factor for Nb-Ta mineralization of the Toudaoqiao.

The newly discovered high Nb–Ta alkaline rhyolite in Tuohelinchang, the Great Xing’an Range volcanic belt, China, represents a potential volcanic-related Nb–Ta deposit. Nb is primarily hosted by ilmenite-(Nb) and zircon-(Nb). In this study, we present U–Pb zircon ages, Hf isotope compositions, and whole-rock geochemical data to elucidate the evolution of Tuohelinchang alkaline rhyolite. The mineralization occurred in the Early Cretaceous, as indicated by magmatic zircon ages. The positive εHf(t) values range from 8.78 to 12.16 with TDM2 of 606–393 Ma. Additionally, geochemical characteristics of K2O/Na2O ratios > 1 and Mg# < < 40 indicate that the magma originated from partial melting of Neoproterozoic–Paleozoic potassium-rich intermediate–mafic juvenile lower crust. Under the Early Cretaceous extensional tectonic background of the Great Xing’an Range, rollback and subduction of the Paleo-Pacific plate triggered upwelling of asthenospheric mantle material, which heated and partially melted the lower crust. The parental magma experienced highly differentiated evolution driven by F and other volatiles, leading to continuous enrichment of Nb–Ta in the residual melt and subsequent mineralization.

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 Hongqiling large nickel-copper-cobalt deposit (hereafter referred to as the Hongqiling deposit), a typical mafic-ultramafic copper-nickel deposit in China, boasts proven Ni (Ni) resources of approximately 22×104 t, associated copper resources of 2×104 t, and associated cobalt (Co) resources of 0.5×104 t, with Ni reserves ranking 10th among China’s magmatic nickel deposits. Geotectonically, the Hongqiling deposit is situated in the superimposed zone between the Xing’an-Mongolian orogenic belt and the circum-Western Pacific’s active continental margin belt. Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group, with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone. In the deposit, the rock assemblages of ore-bearing plutons predominantly encompass gabbro - pyroxenite - olivine pyroxenite - pyroxene peridotite (pluton No. 1) and noriteorthopyroxenite-harzburgite (pluton No. 7), with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies. The Hongqiling deposit hosts stratoid, overhanging lentoid, veined, and pure-sulfide veined orebodies. Its ores principally contain metallic minerals including pyrrhotite, pentlandite, chalcopyrite, violarite, and pyrite. Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks, it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination. The ore-forming materials were primarily derived from the upper mantle, mixed with minor crustal materials. The ore-bearing mafic-ultramafic rocks in the deposit, primarily emplaced during the Indosinian (208–239 Ma), were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic. From the perspective of the metallogenic geological setting, surrounding rocks, ore-controlling structures, and rock assemblages, this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit. These serve as valuable references for exploring similar nickel deposits in the region, as well as the deep parts and margins of the Hongqiling deposit.

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 southern Great Xing’an Range is located in the eastern Central Asian Orogenic Belt, where voluminous igneous rocks developed during the Late Mesozoic period. The east slope of the southern Great Xing’an Range has been the topic of numerous debates on the level of influence of the Mongol-Okhotsk and the Paleo-Pacific regimes in the Late Mesozoic period. Therefore, this area is a suitable region in which to study the temporal changes in magma sources and tectono-magmatic evolution. In this paper, whole-rock geochemical data, zircon U-Pb geochronology, and zircon Hf isotope studies were carried out on the granitoids in the east slope area of the southern Great Xing’an Range. LA-ICP-MS zircon U-Pb dating revealed the ages of four granitoid samples: 135.0 ± 0.6 Ma, 130.7 ± 1.4 Ma, 130.4 ± 1.0 Ma, and 127.6 ± 0.8 Ma, respectively. The Hf isotope values 176Hf/177Hf = 0.282751–0.283015, εHf (t) = +2.0~+11.5, and T2DM = 583~1442 Ma suggest that the magma was generated by partial melting of Meso- and Neoproterozoic accreted and thickened low crust. The whole-rock geochemical data implied that these granitoids are A-type granite and their formation is closely linked to the subduction of the Paleo-Pacific Ocean plate. These geochemical, isotopic, and geochronological data suggest that the Early Cretaceous magmatism in the east slope area of the southern Great Xing’an Range formed in an extensional back-arc tectonic setting associated with the slab roll-back of the Paleo-Pacific plate subduction.

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.

三泉西硅灰石矿位于吉林省磐石市.本文对其矿床地质特征、矿体特征及矿石特征等进行初步调查,三泉西硅灰石矿床已知矿体均产于燕山期钾长花岗岩与上石炭统磨盘山组大理岩外接触带,矿体与围岩界线清楚.矿石类型为硅灰石-方解石-石英型.矿体与地层产状基本一致,从岩体向外所见为岩浆岩→大理岩→矿体→大理岩,接触带并未成矿,矿体与围岩均无明显的交代现象.通过分析得出,三泉西硅灰石矿体与石炭系碳酸盐建造有生成关系,是产于一定层位的,含硅质碳酸盐被岩浆侵入受热使原岩在新的物理化学条件下形成了新的稳定组合,并生成了硅灰石矿.因此,三泉西硅灰石矿床成因类型为接触变质型矿床.

The Jiashang tungsten molybdenum deposit is located in Northeastern Jiangxi Province. In this paper, We preliminary investigate and count the ore deposit geological features, ore body characteristics, ore characteristics and the characteristics of ore bearing quartz vein. The known ore bodies of Jiashang tungsten molybdenum deposit occur in the quartz vein of metamorphic rock series of the Lower Sinian Shangyuan Group. The overall occurrence of ore-bearing quartz veins is 173°∠83°, the ore types are wolframite quartz vein type and pyrite-molybdenum-wolframe quartz vein type, the main types of surrounding rock alteration are silicitization, sericitization, pyritization, greisenization, fluorite-lithify and chloritization. Through analysis, it is concluded that the main prospecting criteria in the mining area are metamorphic rock series of the Lower Sinian Shangyuan Group, the overall strike of 83° quartz veins and alteration types such as silicification, sericitzation, greisenization and fluorite-lithify.

The Sena copper-gold deposit is one of the important constituent deposits of the Duolong ore-concentration area. In this paper, we investigate the geological features, ore body characteristics, ore characteristics and alteration of the surrounding rocks, etc. Through field research and indoor petrographic and ore-phase analyses, we classify the formation of Sena copper-gold deposit into three mineralization stages: quartz-polymetallic sulfide stage, calcite-pyrite stage and oxidation stage. At the same time, the alteration characteristics of the surrounding rocks of the Sena copper-gold deposit were analyzed, and it is considered that the Sena copper-gold deposit does not have the Rock-centered central face alteration characteristics of typical porphyry deposits. By comparing with the geological characteristics of typical porphyry copper-gold deposit and porphyry-high sulfide epithermal deposit in the area, the characteristics of the Sena copper-gold deposit is porphyry-high sulfide epithermal deposit. According to the geological conditions of ore body, the early Cretaceous quartz diorite porphyrite with sericite and lapianization and Sewachenite quartz sandstone are important prospecting indicators.

The large Bayanbaolege Ag polymetallic ore deposit is located in the Tuquan-Linxi Fe (Sn)-Cu-Pb-Zn-Ag-Nb (Ta) polymetallic metallogenic belt, which is an important part of the Great Xing’an Range metallogenic province, northeast China. The sulfide–quartz vein-type orebodies in the deposit are mainly hosted in the Cretaceous granodiorite porphyry and Late Permian Linxi formation. The U-Pb dating of the zircon from the post-ore diorite porphyrite yields an age of 124.8 ± 1.1 Ma, which constrains the mineralization time at the Early Cretaceous. The Sr-Nd isotope values (87Sr/86Sr)i = 0.708576~0.710536; εNd (t) = −0.51~+0.69; the Hf isotope values 176Hf/177Hf = 0.2827278~0.2830095, the εHf (t) = +3.1~+11.2, TDM2 = 615~1341 Ma of the metallogenic granodiorite porphyry. The Hf isotope values 176Hf/177Hf = 0.2828596~0.2829451, and the εHf (t) = +5.7~+8.8 of the diorite porphyrite, TDM2 = 827~1108 Ma, indicating that the ore-forming materials were the possible involvement of heterogeneous juvenile sources including moderately depleted mantle and newly underplated lower crust. The major and trace elements (including REEs) implied that these intrusions are the I-type granite and linked intimately to the westward subduction of the Paleo-Pacific Ocean plate. From these whole-rock major and trace elements and zircon U-Pb ages, as well as Sr-Nd-Hf isotope data, we conclude that the ore-associated I-type granites in the Bayanbaolege deposit formed in an extensional tectonic setting of the Early Cretaceous, and are compactly related to the retreat of the Paleo-Pacific Ocean subducted plate linked intimately to the westward subduction of the Paleo-Pacific Ocean plate rather than the closure of the Mongol–Okhotsk Ocean. Furthermore, by integrating geological background work and previous research work, implying the mineralization age of the Bayanbaolege deposit should have been formed in the 125–130 Ma.

地质填图是所有地质院校地质基础实习必须要学习和掌握的主要地质技能之一。自从数字地质填图（DGSS）的产生，其已经 被全国地质生产单位应用到区域地质调查中，这使得将数字地质填图技术引入到高校实习教学中去成为必然。本文以于长春工程学院地质基 础实习为例，探讨数字地质填图技术引入到地质基础实习中的可行性与必要性。

The Yangbishan iron–tungsten deposit, located in the central part of the Jiamusi Massif, Heilongjiang Province, NE China, is the oldest tungsten deposit in NE China to date. Both ore‐forming conditions and mineralisation characteristics indicate that tungsten mineralisation belongs to the skarn type. Petrography, microthermometric measurements and laser Raman spectroscopy of fluid inclusions in quartz grains associated with scheelite indicate that the ore‐forming fluid of the tungsten mineralisation in Yangbishan deposit belonged to the moderate‐temperature NaCl–H2O–CH4±N2 system. Fluid inclusion analyses indicate that ore‐forming fluid experienced decreasing temperatures and fluid degassing, inducing scheelite precipitation. Analysis of C, H and O isotopes of fluid inclusions within scheelite grains show δ13C values varying from −20.7 to −24.9‰, δD from −109.9 to −119.9‰, δ18O from 6.8 to 10.0‰ and δ18OH2O from 8.7 to 11.9‰. These data, together with C, H and O isotope compositions of the quartz associated with scheelite in tungsten ores, imply that ore‐forming fluid was derived dominantly from magma but influenced by organic material (reducing carbon) derived from wall rocks. Sm/Nd ratios of scheelite vary from 0.15 to 0.21, εNd (t = 520 Ma) values from −5.64 to −17.95 (average of −10.21) and TDM2 values from 702 and 2693 Ma (average of 2070 Ma), indicating the ores were sourced from ancient crustal rocks. The compositions of C–H–O–S–Pb and Nd isotopes support the fact that interaction between crust‐derived magma and strata rich in organics played an important role in the tungsten mineralisation of the Yangbishan deposit.

兴东群是佳木斯地块的结晶基底和多个铁、金、钨矿床(点)的含矿地层.为厘定其形成时代,揭示其地质和成矿意义,选取黑龙江省林口地区的兴东群大盘道组,在剖面实测、岩相学研究基础上,开展了代表性岩石的碎屑锆石U-Pb年代学研究.结果表明,所测大盘道组的主要岩石类型为大理岩与石英片岩,其原岩为灰岩及泥岩,变质程度可达角闪岩相,沉积于浅海陆棚相环境;石英片岩中碎屑锆石的LA-ICP-MS U-Pb年龄为(2338±20)Ma～(751±18)Ma,存在952 Ma、898 Ma、820 Ma及761 Ma 4个年龄峰值.结合羊鼻山地区大盘道组地层内有～520 Ma的花岗岩侵入以及该区域经历了～500 Ma的泛非期变质作用,确定大盘道组原岩沉积于新元古代—早古生代.本文测年结果显示有4个年龄峰值,其中898 Ma和761 Ma与前人报道的峰期年龄为898～891 Ma和757～751 Ma的两期岩浆事件相对应,另两组所测锆石也均为岩浆成因锆石,反映该区兴东群的物源复杂,且以岩浆岩为主.多期次岩浆作用使大盘道组富集Au、Cu、Pb、Zn、Fe等金属成矿元素,为羊鼻山铁钨矿床、孟家岗铁矿床和七星河金矿床等金属矿床形成提供了丰富的成矿物质基础.

The Hekoulinchang tin polymetallic deposit in Baoqing County of Heilongjiang Province is the first one discovered in the eastern part of the Northeast China. Tectonically, this deposit is located in Wandashan Terrane of eastern Xing'an-Mongolian Orogenic Belt. Its average grades of tin, silver, lead and zinc are 0.27%, 122.89g/t, 0.84% and 1.43%, respectively. This deposit is a medium-sized tin-silver deposit, and small-sized lead-zinc deposit. The thin-vein and stockwork tin polymetallic ore bodies are dominantly hosted within the granite porphyry body and its contact zone with the Upper Triassic Dajiahe Formation. According to the detailed field geological survey and data analysis, the ore-hosting granite porphyry should be the metallogenic intrusion. LA-ICP-MS zircon U-Pb dating of the granite porphyry yields an age of 118.0 +/- 1.1Ma, indicating that the intrusion emplaced at late Early Cretaceous. Its petro-geochemical characteristics show that the granite porphyry belongs to I-type granite and high-medium-K calc-alkaline series, characterized by high contents of SiO2 and K2O, low contents of Fe2O3T, MgO, CaO, and transition elements. The zircon Hf isotope compositions of the granite porphyry samples indicate that the zircon has positive epsilon(Hf)(t) values ( +3.4 similar to +7.4), and the two-stage Hf model age (t(DM2)) of 701 similar to 956Ma. The whole-rock lead isotope in granite porphyry has the characteristics of those in orogenic belt and subduction zone, as Pb-206/Pb-204 = 18.414 similar to 18.460, Pb-207/Pb-204 = 15.591 similar to 15.596, Pb-208/Pb-204 = 38.470 similar to 38.761. The initial Sr value (Sr-87/Sr-86)i of the granite porphyry is 0.708136 similar to 0.708331, and the value of epsilon(Nd)(t) is -2.0 similar to -3.0. Due to studies on the petro-geochemistry and Sr-Nd-Pb-Hf isotopes, it can be concluded that the original magma of the Hekoulinchang granite porphyry was mainly derived from partial melting of the basic juvenile lower crustal material and mixed with upper sedimentary materials in a subduction zone. Based on isotope dating and geochemical data in this paper, as well as knowledge of the regional tectonic evolution, it can be concluded that both the Hekoulinchang granite porphyry and associated tin polymetallic mineralization are closely related to the subduction of the Paleo-Pacific Plate to the Eurasian Plate.

鸡南铁矿床位于吉林省和龙地区,地处华北克拉通北缘与兴蒙造山带接壤的龙岗地块北部,是东北地区发现较早的BIF型铁矿床之一.该矿床铁矿体主要呈层状、似层状、扁豆状赋存于鞍山群鸡南组上段中部层位,含矿岩石以黑云斜长片麻岩、角闪黑云斜长片麻岩、黑云角闪斜长片麻岩及斜长角闪岩为主,为角闪岩相的中低级区域变质岩系;主要矿石类型为条带状磁铁石英岩型和块状磁铁角闪岩型.为确定该矿床含矿建造的原岩、变质时代及构造背景,重点对含矿岩系中的斜长角闪岩进行了岩石地球化学和锆石U-Pb年代学研究.结果 表明:斜长角闪岩的地球化学特征表现为富集大离子亲石元素、轻微富集重稀土元素;主量元素质量分数与中性-基性岩类基本相似,结合原岩恢复图解,判断其原岩类型为亚碱性玄武岩(拉斑玄武岩),形成于弧后盆地背景;LA-ICP-MS锆石U-Pb年代学研究中,2个较老的锆石测点年龄分别为(2 468±15)和(2 469±9)Ma,代表区内峰期变质年龄(约2 460 Ma),26个锆石测点的测年数据较为集中,加权平均年龄为(2 275±25)Ma,代表区内退变质年龄.通过与国内外典型BIF型铁矿床的对比研究认为,区内的鸡南铁矿与官地铁矿同属Algoma型铁矿床.

The Shajingou gold deposit is a recently discovered medium-scale gold deposit in southeastern Jilin Province, Northeast China. The deposit is located in the easternmost segment of the northern margin of the North China Craton (NCC). This study investigated the mineralization age and tectonic setting of the Shajingou gold deposit based on geology, microthermometry and H-O isotopic analyses of fluid inclusions (FIs), pyrite Re-Os and zircon U-Pb dating, petro-geochemistry and zircon Hf isotopic analyses. The findings are placed in the wider context of mesothermal gold metallogeny in Northeast China. Metallogenesis of the gold deposit can be divided into three stages based on the ore mineral assemblage: quartz-K-feldspar-pyrite (stage I), quartz-polymetallic sulfide-native gold (stage II) and quartz-carbonate (stage III). Four types of primary FI were identified in quartz and calcite minerals: liquid-rich aqueous (L-type), CO2-bearing (C1-type), CO2-rich (C2-type) and CO2-pure (C3-type). From stage I to stage III, the fluid inclusion suite changes from L-type and C2-type in stage I, all four types in stage II and only L-type in stage III. Homogenization temperatures of stages I to HI are 318-394 degrees C, 264-356 degrees C and 202-276 degrees C, respectively. Salinities of stages I-III are 7.31-12.42, 2.02-8.94 and 0.53-3.53 wt% NaCl equiv., respectively. The ore-forming fluid system evolved from a H2O-NaCl-CO2 system in stages I and II to a H2O-NaCl system in stage HI. During the stage H, the addition of meteoric water led to decreases in temperature and pressure, resulting in an immiscible H2O-NaCl-CO2 fluid system. This immiscibility in turn led to the escape of CO2 and other volatiles, the increase of pH and the decrease in solubility and stability of Au-S clathrates, thus facilitating the deposition of gold and associated polymetallic sulfides. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U-Pb dating of the Shajingou diorite yielded a weighted mean Pb-206/U-238 age of 171.7 +/- 0.9 Ma (MSWD = 3.0). Re-Os dating of the gold-bearing pyrite yielded an isochron age of 166 +/- 29 Ma (MSWD = 5.2). The Shajingou diorite has high concentrations of SiO2, Al2O3, Na2O, Mg#, Cr and Ni, weakly positive Eu anomalies, and is LREE- and LILE-enriched, HREE- and HFSE-depleted, as well as has positive epsilon(Hf) (t) values (+3.0 to +7.1). This indicates the diorite was sourced from the partial melting of a depleted-mantle wedge that had been modified by the subducted- slab-derived fluids. The deposit geology, ore genesis, geochronology and tectonic setting of the Shajingou gold deposit differ from those of other gold deposits in the eastern segment of the XMOB, but are similar to those of gold deposits in the Jiapigou-Haigou gold belt (JHGB) of southeastern Jilin Province at the northern margin of the NCC. These findings suggest the JHGB extends southeastward to the Helong area of Yanbian, which indicates the need for further research on the gold mineralization potential of the southeastern JHGB and further gold prospecting in the region. Comparative studies of Shajingou and other gold deposits in the JHGB have confirmed that a significant tectonic-magmatic-hydrothermal event occurred during the Middle Jurassic due to the subduction of the Paleo-Pacific Plate beneath the Eurasian Plate.

The Dongfengnanshan Cu polymetallic deposit is one representative deposit of the Tianbaoshan ore district in the Yanbian area, northeast (NE) China. There occur two types of ore bodies in this deposit, the stratiform ore bodies and vein‐type ones, controlled by the Early Permian strata and the Late Hercynian diorite intrusion, respectively. Due to the ambiguous genetic type of the stratiform ore bodies, there has been controversy on the relationship between them and vein‐type ore bodies. To determine the genetic type of stratiform ore bodies, laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) in situ trace elements and S–Pb isotope analysis have been carried on the sulfides in the stratiform ore bodies. Compared with that in skarn, Mississippi Valley‐type (MVT), and epithermal deposits, sphalerite samples in the stratiform ore bodies of the Dongfengnanshan deposit are significantly enriched in Fe, Mn, and In, while depleted in Ga, Ge, and Cd, which is similar to the sphalerite in volcanic‐associated massive sulfide (VMS) deposits. Co/Ni ratio of pyrrhotites in the stratiform ore bodies is similar to that in VMS‐type deposits. The concentrations of Zn and Cd of chalcopyrites are similar to those of recrystallized VMS‐type deposits. These characteristics also reflect the intermediate ore‐forming temperature of the stratiform ore bodies in this deposit. Sulfur isotope compositions of sulfides are similar to those of VMS‐type deposits, reflecting that sulfur originated from the Permian Miaoling Formation. Lead isotope compositions indicate mixed‐source for lead. Moreover, the comparison of the Dongfengnanshan stratiform ore bodies with some VMS‐type deposits in China and abroad, on the trace elements and S–Pb isotope characteristics of the sulfides reveals that the stratiform ore bodies of the Dongfengnanshan deposit belong to the VMS‐type, and have closely genetic relationship with the early Permian marine volcanic sedimentary rocks.

The giant Pulang porphyry Cu (–Mo–Au) deposit in Northwestern Yunnan Province, China, is located in the southern part of the Triassic Yidun Arc. The Cu orebodies are mainly hosted in quartz monzonite porphyry (QMP) intruding quartz diorite porphyry (QDP) and cut by granodiorite porphyry (GP). New LA-ICP-MS zircon U–Pb ages indicate that QDP (227 ± 2 Ma), QMP (218 ± 1 Ma, 219 ± 1 Ma), and GP (209 ± 1 Ma) are significantly different in age; however, the molybdenite Re–Os isochron age (218 ± 2 Ma) indicates a close temporal and genetic relationship between Cu mineralization and QMP. Pulang porphyry intrusions are enriched in light rare-earth elements (LREEs) and large ion lithophile elements (LILEs), and depleted in heavy rare-earth elements (HREEs) and high field-strength elements (HFSEs), with moderately negative Eu anomalies. They are high in SiO2, Al2O3, Sr, Na2O/K2O, Mg#, and Sr/Y, but low in Y, and Yb, suggesting a geochemical affinity to high-silica (HSA) adakitic rocks. These features are used to infer that the Pulang HSA porphyry intrusions were derived from the partial melting of a basaltic oceanic-slab. These magmas reacted with peridotite during their ascent through the mantle wedge. This is interpreted to indicate that the Pulang Cu deposit and associated magmatism can be linked to the synchronous westward subduction of the Ganzi–Litang oceanic lithosphere, which has been established as Late Triassic.

Four genetic types and over ten deposits (mineral occurrences) have been discovered in the Tianbaoshan metallogenic region in Yanbian area, including Lishan and Xuanchanghoushan skarn-type lead-zinc-copper deposits, Xinxing cryptoexplosive breccia-type lead-zinc (silver) deposit, Dongfengnanshan sedimentary-hydrothermal copper-lead-zinc deposit and Dongfengbeishan porphyry molybdenum deposit. To better understand metallogenic sequence of polymetallic mineralization in Tianbaoshan region, sulfide Rb-Sr dating and LA-ICP-MS zircon U-Pb dating of intrusion associated with polymetallic mineralization in the Xinxing lead-zinc ( silver) deposit have been carried out. LA-ICP-MS zircon U-Pb dating of 16 analytical spots from the metallogenic granodiorite obtains the weighted mean Pb-206/ U-238 age of 261. 1 +/- 3. 5Ma ( MSWD =0.46) , and Rb-Sr dating of six sulfide samples from breccia-type ore yields an isochron age of 259 +/- 3Ma (MSWD =1. 05) , with initial Sr isotopic composition I-Sr =0. 71359 , implying the close temporal and genetic link between magmatism and mineralization. These consistent isotopes dating results show that both the emplacement of granodiorite and associated lead-zinc mineralization can be constrained to the end of middle Permian. Based on isotope dating results in this paper and existing isotope dating data, it can be concluded that Lishan, Xuanchanghoushan and Xinxing polymetallic deposits formed in Middle-Late Permian (255 similar to 265Ma) , and Dongfengbeishan porphyry molybdenum deposit formed in the Early Jurassic ( similar to 192Ma). The Rb and Sr contents in six sulfide mineral samples range from 0. 1238 x 10(-6) to 0. 7536 X 10(-6) , 0. 3786 X 10(-6) to 3. 247 x 10(-6) , respectively, and the initial Sr isotope ratios (Sr-87/Sr-86) , range from 0. 71350 to 0. 71371, with an average of 0. 71361. Rb and Sr contents indicate that metallogenic materials of the Xinxing lead-zinc ( silver) deposit mainly derived from the crust, and mixed with small amount of mantle material. Comprehensive studies show that during the Middle-Late Permian ( 255 similar to 265 Ma ) , the subduction of the Paleo-Asian Ocean Plate led to partial melting of the lower crust and the crust-mantle-derived mixed granodioritic magma rich in Cu, Pb, Zn and Ag. The granodioritic magma moving upward along structures and emplacing at the shallow crust, on the one hand, resulted in Late Palaeozoic metallogenic and ore-hosting intermediate-acid intrusions in Tianbaoshan metallogenic region including Lishan, Xinxing and Dongfengbeishan intrusions, on the other hand, derived the ore-forming fluid which caused the Lishan and Xuanchanghoushan skarn lead-zinc-copper deposits within and near the contact zone between granodiorite and marble. Due to continuous accumulation of magmatic hydrothermal fluid and volatile components at the top of the magma chamber, inner pressure of the fluid exceeded outer pressure and led to explosions and fracturing of the roof granodiorites, and led to the ore-controlling cryptoexplosive breccia pipe. Fluid immiscibility caused by a sharp drop of hydrothermal pressure resulted in hydrothermal alteration and mineralization, precipitation of such metal minerals as Pb, Zn and Ag, as well as Xinxing cryptoexplosive breccia pipe-type lead-zinc ( silver) deposit.