Ore-forming mechanism of Huxu Au-dominated polymetallic deposit in the Dongxiang Basin,South China:Constraints from in-situ trace elements and S-Pb isotopes of pyrite

The Huxu Au-dominated polymetallic deposit is a hydrothermal deposit located in the Dongxiang volcanic basin in the middle section of the Gan-Hang tectonic belt in South China.The orebodies primarily occur within the Jurassic-Cretaceous quartz diorite porphyry,while the genesis of this deposit is unclear.This study focused on geological and mineralogical characteristics,in-situ trace elements and S-Pb isotopes of three generations of pyrite of the Huxu deposit to clarify the distribution of trace elements in pyrite,ore-forming fluid and material sources,and genetic types of the deposit.The mineralization stage of the deposit can be divided into quartz-pyrite stage(S1),quartz-pyrite-hematite stage(S2),quartz-polymetallic sulfide stage(S3)and quartz-hematite stage(S4),with the corresponding pyrite being divided into three generations(Py1-Py3).in-situ trace element data of pyrite show that Au in pyrite mainly exists in the form of solid solution(Au^(+)),and the content is relatively low at all stages(0.18 ppm for Py1,0.32 ppm for Py2,0.68 ppm for Py3),while Pb and Zn mainly exist as sulfide inclusions in the pyrite.S-Pb isotopes show that the sulfur and ore-forming material of this deposit are mainly sourced from magma.The mineral association,mineral textures and trace elements in different stages of pyrite indicate that fluid boiling and fluid mixing are the key factors of native gold precipitation in S2 and S4,respectively,while water-rock interaction controlled the precipitation of Pb-Zn sulfides.These integrating with geological characteristics suggests that the deposit should be an intermediate sulfidation epithermal deposit.

Late Mesozoic Ore-forming Events in the Ningwu Ore District, Middle-Lower Yangtze River Polymetallic Ore Belt, East China: Evidence from Zircon U-Pb Geochronology and Hf Isotopic Compositions of the Granodioritic Stocks

Late Mesozoic volcanic-subvolcanic rocks and related iron deposits, known as porphyry iron deposits in China, are widespread in the Ningwu ore district （Cretaceous basin） of the middle-lower Yangtze River polymetallic ore belt, East China. Two types of Late Mesozoic magmatic rocks are exposed： one is dioritic rocks closely related to iron mineralization as the hosted rock, and the other one is granodioritic （-granitic） rocks that cut the ore bodies. To understand the age of the iron mineralization and the ore-forming event, detailed zircon U-Pb dating and Hf isotope measurement were performed on granodioritic stocks in the Washan, Gaocun-Nanshan, Dongshan and Heshangqiao iron deposits in the basin. Four emplacement and crystallization （typically for zircons） ages of granodioritic rocks were measured as 126.1±0.5 Ma, 126.8±0.5 Ma, 127.3±0.5 Ma and 126.3±0.4 Ma, respectively in these four deposits, with the LA-MC-ICP-MS zircon U-Pb method. Based on the above results combined with previous dating, it is inferred that the iron deposits in the Ningwu Cretaceous basin occurred in a very short period of 131-127 Ma. In situ zircon Hf compositions of εHf（t） of the granodiorite are mainly from -3 to -8 and their corresponding 176Hf/177Hf ratio are from 0.28245 to 0.28265, indicating similar characteristics of dioritic rocks in the basin. We infer that granodioritic rocks occurring in the Ningwu ore district have an original relationship with dioritic rocks. These new results provide significant evidence for further study of this ore district so as to understand the ore-forming event in the study area.

Characteristics of Pegmatite-Related Fluids and Significance to Ore-Forming Processes in the Zhaxikang Pb-Zn-Sb Polymetallic Deposit,Tibet,China

The Zhaxikang Pb-Zn-Sb polymetallic deposit is one of the most important deposits in the newly recognized southern Tibet antimony-gold metallogenic belt.Compared to the porphyry deposits in the Gangdese belt,much less researches have addressed these deposits,and the genesis of the Zhaxikang deposit is still controversial.Based on field investigation,petrographic,microthermometric,Laser Raman Microprobe（LRM） and SEM/EDS analyses of fluid,melt-fluid,melt and solid inclusions in quartz and beryl from pegmatite,this paper documents the characteristics and the evolution of primary magmatic fluid which was genetically related to greisenization,pegmatitization,and silification in the area.The results show that the primary magmatic fluids were derived from unmixing between melt and fluid and underwent a phase separation process soon after the exsolution.The primary magmatic fluids are of low salinity,high temperature,and can be approximated by the H_2O-NaCl-CO_2 system.The presence of Mn-Fe carbonate in melt-fluid inclusions and a Zn-bearing mineral（gahnite） trapped in beryl and in inclusions from pegmatite indicates high Mn,Fe,and Zn concentrations in the parent magma and magmatic fluids,and implies a genetic link between pegmatite and Pb-Zn-Sb mineralization.High B and F concentrations in the parent magma largely lower the solidus of the magma and lead to late fluid exsolution,thus the primary magmatic fluids related to pegmatite have much lower temperature than those in most porphyry systems.Boiling of the primary magmatic fluids leads to high-salinity and high-temperature fluids which have high capacity to transport Pb,Zn and Sb.The decrease in temperature and mixing with fluids from other sources may have caused the precipitation of Pb-Zn-Sn（Au） minerals in the distal fault systems surrounding the causative intrusion.

Ore-forming fluid characteristics and ore-forming materials source of the Tudimiaogou – Yindongshan lead-zinc polymetallic orefield, west Henan

1 Introduction The Tudimiaogou-Yindongshan lead-zinc polymetallic orefield is located in the Tudimiaogou-Weimoshi lead and zinc silver polymetallic metallogenic belt.The belt is an important part of southwestern Henan lead and zinc

Characteristics and evolution of ore-forming fluids of the Chongjiang copper deposit in the Gangdise porphyry copper belt, Tibet

Petrography, microthermometry, and scanning electron microscope/energy dispersive spectrometer （SEM/EDS） studies were performed on the fluid inclusions in the ore-beating quartz veins and quartz phenocrysts in the porphyry of the Chongjiang porphyry copper deposit. The analyses of the fluid inclusions indicate that the ore-forming fluids were exsolved from magma. They are near-saturated, supercritical, rich in volatile constituents, and have the capture temperature of 362-389℃ and salinities of 17.7wt%- 18.9wt% NaC1 eq. With the decreasing of temperature and pressure, the supercritical fluids were separated into a low salinity vapor phase and a high salinity liquid phase. During quartz-sericitization, the high salinity fluid boiled and separated into a low salinity vapor phase and a high salinity liquid phase. The high salinity inclusions that formed in the boiling process had daughter mineral melting temperatures higher than the homogenization temperatures of the vapor and liquid phases. The late fluids that are responsible for argillization are of lower temperature and salinity.

Geochronology and geochemistry of the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(73240 t) in Heilongjiang Province, China

The Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(20000 t Sn at 0.27%,236 t Ag at 122.89 g/t,15000 t Pb at 0.84%,and 38000 t Zn at 1.43%)is located in the Wandashan Terrane of the easternmost segment of the Central Asian Orogenic Belt.The timing of Sn-Pb-Zn-Ag polymetallic mineralization remains unclear due to a lack of precise isotope dating directly conducted on ore minerals.The authors herein report that the LA-ICP-MS U-Pb ages of cassiterite and zircon from the granite porphyry in the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit are 101.4±7.9 Ma and 115.4±1.0 Ma,respectively,indicating that Sn mineralization and magmatism occurred during the Early Cretaceous.The granite porphyry belongs to the subalkaline series peraluminous I-type granites that are depleted in Nb,Ta,and Ti and enriched in Rb,Th,U,and Pb.TheεHf(t)values of the granite porphyry range from 0.9 to 7.4,with an average of about 5.6 and two-stage model ages(T_(DM2))of 705–1116 Ma,with an average age of 819 Ma.The ε_(Nd)(t)values of the apatites are–1.60–0.45,with an average of–0.9,and two-stage model ages(T_(DM2))of 872–1040 Ma,with an average age of 983 Ma.The Nd-Hf isotope data indicate that the magma may have been derived from the partial melting of juvenile crustal material.

Discussion on the Source of Ore-forming Materials of the Yinan Gold Deposit,Shandong

Based on the main characteristics of the tectonic -magmatic evolution of region and Tanlu fault zone,we have discussed ore-bearing magmatic rocks petrochemistry,strontium and lead isotope,and the source of ore-forming materials in Yinan skarn deposit in this paper.The petrochemical features show that the ore-bearing magmatic rocks are calc-alkaline rocks of sub-alkaline series formed during

红尖兵山钨多金属矿床锆石、黑钨矿、日光榴石U-Pb年代学及地球化学:对北山造山带三叠纪关键金属成矿作用的启示

北山成矿带是我国西北地区重要的战略性金属矿产资源地之一,区内的岩浆岩年代学工作已得到广泛开展,但对成矿带内成岩与成矿关系等缺乏系统研究。红尖兵山作为北山成矿带最具代表性的钨多金属矿床受到了较多关注,但其成矿时代、矿床成因等一直存在较大争议,已成为理解区域成矿构造事件的重要制约因素。本文对红尖兵山矿床详细的野外地质调查工作显示,该矿床成矿岩体为双驼峰式二长花岗岩,矿化类型可以划分为云英岩型矿石和黄玉-石英脉型矿石。对红尖兵山成矿岩体中的锆石、云英岩型矿石中的黑钨矿和黄玉-石英脉型矿石中的日光榴石进行了LA-ICP-MS U-Pb年代学,研究结果显示其形成时代分别为221.7±1.3 Ma、221.6±2.1 Ma、220.5±7.9 Ma,指示红尖兵山的成岩成矿时代在误差范围内一致,是晚三叠世岩浆-热液活动的产物。黑钨矿、日光榴石和白云母的LA-ICP-MS成分分析结果显示,黑钨矿中富集Sc、Mo等元素,而日光榴石和白云母则分别富集Be、Zn、Sc和Li、Sc关键金属等元素。通过主成分分析(PCA)和元素相关性分析,揭示了黑钨矿、日光榴石和白云母中关键金属元素的赋存状态。综合分析显示,红尖兵山矿床形成于陆内造山后伸展构造背景下,在强烈的岩石圈伸展减薄和幔源岩浆底侵诱发下,地壳发生部分熔融产生的酸性岩浆经分异演化形成的岩浆热液与围岩相互作用后形成富含挥发组分、偏还原、低pH和低Eh的成矿流体,它们沿构造薄弱部位充填交代形成石英脉-云英岩型钨多金属矿床。本研究成果对于理解北山造山带三叠纪陆内伸展构造背景下构造-岩浆-成矿事件具有重要意义,并为该区域同类矿床的勘查和关键金属找矿提供了指导。

Identification of the anomaly component using BEMD combined with PCA from element concentrations in the Tengchong tin belt, SW China

Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal component analysis)and be separated into two components using BEMD(bi-dimensional empirical mode decomposition):(1)a high background component which represents the ore-forming background developed in rocks through various geological processes favorable for mineralization(i.e.magmatism,sedimentation and/or metamorphism);(2)the anomaly component which reflects the oreforming anomaly that is overprinted on the high background component developed during mineralization.Anomaly components are used to identify ore-finding targets more effectively than ore-forming element groups.Three steps of data analytical procedures are described in this paper;firstly,the application of PCA to establish the ore-forming element group;secondly,using BEMD on the o re-forming element group to identify the anomaly components created by different types of mineralization processes;and finally,identifying ore-finding targets based on the anomaly components.This method is applied to the Tengchong tin-polymetallic belt to delineate ore-finding targets,where four targets for Sn(W)and three targets for Pb-Zn-Ag-Fe polymetallic mineralization are identified and defined as new areas for further prospecting.It is shown that BEMD combined with PCA can be applied not only in extracting the anomaly component for delineating the ore-finding target,but also in extracting the residual component for identifying its high background zone favorable for mineralization from its oreforming element group.

A Metallogenic Model of Gold Deposits of the Jiaodong Granite-Greenstone Belt

An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Indosinian, the Tancheng-Lujiang fault zone cut deeply into the upper mantle so that the ore-bearing fluids migrated to higher layers through the crust-mantle interaction, resulting in alteration and mineralization.

THE CHARACTERISTICS OF GEOLOGICAL GENERAL FIELD OF VOLCANIC BELT IN LANCANG RIFT VALLEY AND ITS SIGNIFICANCE FOR EXPLORATION

Based on the theory of dissipative structures and moving character-parameters of elements,this paper examines the characteristics of the geological general field of volcanic belt in the Lancang rift valley,west Yunnan,China-with an open system and lower pressure environment,the volcanic belt is characterized by a large scale continuously graduating dissipative structure and three orders of concentrated minerogenetic material fields,and by the energy fields that influence the time and space structure of material fields.The research shows that the third order minerogenetic material fields which surround volcanic eruptive centers and have hydrothermal superposition and reconstruction after the magma stage possess favorable prognosis targets for copper polymetal.

东秦岭钼多金属成矿带夜长坪斑岩-矽卡岩型钼钨矿床磁铁矿成因类型与指示意义

夜长坪超大型斑岩-矽卡岩型钼钨矿床位于东秦岭钼多金属成矿带,保存了完整的矽卡岩形成演化及成矿作用的重要信息。通过详细的野外地质调查及镜下鉴定,将夜长坪钼钨矿床中的磁铁矿划分为3种类型:晚矽卡岩阶段形成以他型粒状或以聚合体形式与黑云母、绢云母、黏土等矿物共生的Mt1型磁铁矿;氧化物阶段形成半自形至自形与石榴子石、透闪石、阳起石等矿物共生的Mt2型磁铁矿;呈稠密浸染状与辉钼矿等硫化物共生,或产出在石英多金属硫化物脉中的Mt3型磁铁矿。电子探针及LA-ICP-MS原位测试分析结果显示:Mt1~Mt3型磁铁矿FeO平均含量逐渐升高,Mt1型磁铁矿富Si、Mg、Na等元素,具有最高的V、Cr、Ti、Al和Mo含量。Mt2型磁铁矿Ti元素含量明显降低,Si含量略有下降,具有最高含量的Mg和Mn。Mt3型磁铁矿中Ti、Si、Na、Ca元素含量均最低。磁铁矿元素变化特征显示,Fe元素易被Si、Ca、Al等元素替换;随磁铁矿的结晶,成矿流体中逐渐富集Mo等成矿元素。磁铁矿成因判别图解显示,Mt1型磁铁矿与另外2种磁铁矿形成物质来源略有不同,Mt1型磁铁矿更偏向于岩浆热液成因,Mt2型磁铁矿和Mt3型磁铁矿则更偏向于变质热液成因,随着Mt2型磁铁矿的形成,赋矿围岩参与成矿的程度逐渐增强。从早期较高温的Mt1型磁铁矿至晚期较低温的Mt3型磁铁矿,V和Ti具有较为明显的正相关关系;流体-岩石作用程度判别图解显示交代作用逐渐增强。因此,在夜长坪钼钨矿床氧逸度的变化和流体-岩石作用程度的逐渐增强是控制成矿的主要因素。

西藏甲玛铜多金属矿电气石矿物学特征及其对热液流体演化的指示

【研究目的】角岩作为甲玛超大型斑岩铜多金属成矿系统的重要组成部分,既是成矿热液的岩性圈闭,也是重要的赋矿围岩,但角岩中的电气石成因不明,对于进一步理解成矿过程有一定制约。【研究方法】本文通过详细的钻孔编录、镜下鉴定和电子探针分析,研究电气石的成因,并探讨其对岩浆热液流体演化过程的启示。【研究结果】电气石在甲玛角岩中较为发育,依据其产状可分为4类:Tur-I,热液角砾岩胶结物中的电气石;Tur-Ⅱ,石英+电气石±黄铁矿脉;Tur-Ⅲ,电气石±黄铁矿±黄铜矿脉;Tur-Ⅳ,团斑状电气石±黄铁矿;其中前3类电气石较发育环带结构。不同产状电气石均具有较为宽泛的Al_(2)O_(3)、Fe/(Fe+Mg)和Na/(Na+Ca)比值,属于碱基亚类镁电气石和黑电气石,替代机制为^(X)□Al(NaMg)_(-1)、Fe^(2+)Mg_(-1)和Fe^(3+)Al_(-1)。【结论】不同产状电气石发育复杂的环带结构,且成分变化极大,表明其是岩浆热液流体和地层流体不同程度混合造成的,且岩浆热液流体与还原性的角岩地层发生的水岩反应可能在甲玛成矿过程中起了重要作用。甲玛不同产状电气石的结构和成分信息记录了岩浆热液演化过程的细节信息,为完善成矿过程提供了重要证据。

西藏努日铜多金属矿南矿段地质特征及短波红外光谱的勘查应用

西藏努日斑岩-矽卡岩型矿床作为冈底斯成矿带上发现的唯一具有Cu-W-Mo矿化组合的大型矿床,带上找矿潜力较大,成果丰硕。随着区带成矿理论和矿区研究程度的深入,亟需使用新的方法和技术手段来满足区内深部找矿的需要。本次研究利用短波红外光谱技术SWIR(Short wave infrared),对努日铜多金属矿床南矿段中典型蚀变矿物进行研究,根据其矿床地质特征、蚀变矿物组合、分带特征以及光谱分析结果,总结了矿区典型蚀变矿物短波红外光谱特征值分布规律,进而确定其勘查标志。研究认为白云母的吸收峰位值Pos2200>2208 nm、伊利石的吸收峰位值Pos2200>2203 nm、绿泥石的吸收峰位值Pos2250>2249 nm的大量或连续出现,可以作为努日矿区矽卡岩型铜多金属矿床有效的蚀变矿物勘查指标;在此基础上,综合努日南矿段地质特征分析、蚀变矿物分布规律分析,对矿区深部斑岩型铜矿进行成矿预测,认为南矿段45线东侧深部的石英闪长(玢)岩具有斑岩型铜矿找矿的潜力,为矿区下一步的找矿提供了方向与思路。

大兴安岭成矿带南段大座子山铜多金属矿成矿时代及其地质意义

内蒙古自治区大座子山矿床是大兴安岭成矿带南段近年来新发现的铜多金属矿床。该矿床矿体产于上侏罗统满克头鄂博组流纹岩内,成矿过程可以划分为白色石英-少硫化物(黄铁矿)阶段、烟灰色石英-多硫化物(黄铁矿、闪锌矿、方铅矿、黄铜矿和辉钼矿)阶段和方解石-硫化物(黄铁矿、方铅矿和闪锌矿)阶段。本次研究通过对石英-多金属成矿阶段辉钼矿开展Re-Os定年,获得6个辉钼矿模式年龄为134.4~136.9 Ma,加权平均值为135.5±0.8 Ma,与^(187)Re-^(187)Os等时线年龄(136.2±3.2 Ma)一致,表明其形成于早白垩世,不同于前人依据地层厘定的成矿时代。辉钼矿中Re含量为44.31×10^(-6)~92.93×10^(-6),介于壳幔源区之间,推断成矿物质为壳幔混合来源。结合区域构造-岩浆演化,推断大座子山铜多金属矿床形成于鄂霍茨克洋闭合后陆内垮塌与古太平洋板块后撤-回卷联合作用诱发的伸展背景。

北山成矿带老硐沟金多金属矿床S-Pb-C-O同位素特征及其对矿床成因的约束

老硐沟金多金属矿床是北山成矿带内蒙古段最为典型的金矿床之一,其矿床成因存在较多争议,矿床成矿物质来源方面的研究几近空白。文章基于详细的野外实地调查,选取不同成矿阶段的硫化物和方解石,开展原位S-Pb同位素和C-O同位素测试。研究结果表明,老硐沟金多金属矿床δ34S值为-0.56‰~5.54‰,^(206)Pb/^(204)Pb比值为18.326~18.390,207Pb/^(204)Pb比值为15.563~15.645,^(208)Pb/^(204)Pb比值为38.226~38.390,铅同位素μ值变化范围为9.40~9.55,ω值变化范围为35.77~36.85,方铅矿二阶段模式年龄为232~270 Ma,δ^(13)C值介于-0.04‰~2.93‰之间,表明老硐沟金多金属矿床成矿物质具有岩浆和地层混合来源性质,成矿流体以岩浆来源为主,成矿作用晚期流体中混入了地层变质水。文章从矿床稳定同位素研究方面,结合前人对北山造山带构造演化的认识,提出老硐沟金多金属矿床成因为岩浆热液型。

Geochemistry and Geochronology of the Gebunongba Iron Polymetallic Deposit in the Gangdese Belt, Tibet

The Gebunongba iron polymetallic deposit is a typical skarn deposit located at the westernmost end of the discovered iron polymetallic deposits in the Gangdese metallogenic belt. Major and trace elements of the monzonite granite related to mineralization show that these rocks are peraluminous(ACNK=1.15–1.21) and are rich in Si(76.63 wt.%–76.93 wt.% SiO2), K(K2 O/Na2 O ratio of 1.80–2.30), LREE and LILEs(Rb, Ba, Th, U, Pb), but is depleted in high field strength elements(Nb, Ta, Ti and HREE). In addition, these rocks show obviously negative Eu anomalies(δEu=0.48–0.55). The LA-ICPMS U-Pb age of zircons in monzonite granite is 59.72±0.55 Ma(MSWD=0.79), whereas the 40 Ar/39 Ar age of muscovite in iron ores is 59.22±0.61 Ma(MSWD=16.20). This indicates that the deposit formed at the syn-collision stage of Lhasa-India terrane is later than the northward subduction of the Yajiang crust. The monzonite granite has been probably derived from the partial melting of ancient lower crustal materials, which is probably resulted from the underplating of mantle-derived magmas. It is favorable for the formation of iron polymetallic deposit. Iron polymetallic mineralization is prevalent in Gangdese metallogenic belt at syn-collision stage. Therefore, syn-collision stage is an important mineralization stage for iron polymetallic deposits. The results of this study proved that iron polymetallic mineralization still took place in the western segment of Gangdese metallogenic belt and provided basis for further prospecting the deposits of the same type.

若羌库木萨依伟晶岩特征对锂矿形成的指示意义

研究区位于青藏高原北缘阿尔金铜金成矿带,处于祁连-昆仑构造带、柴达木陆块和塔里木陆块之间。若羌县库木萨依花岗伟晶岩型锂矿具较高的分异程度,轻重稀土分量不明显,可能来源于地壳物质的部分熔融,构造环境为北阿尔金洋回转引起的俯冲环境。通过对库木萨依花岗伟晶岩型锂矿地质特征、矿床成因及资源潜力的研究,为阿尔金地区寻找类似锂矿资源提出方向。

东乡盆地虎圩金多金属矿床金属沉淀机制:来自矿物组合和微量元素的限制

钦杭结合带中部的虎圩金多金属矿床为东乡火山岩盆地内典型热液矿床,基础地质研究表明该矿床赋矿围岩为侏罗纪-白垩纪石英闪长玢岩和流纹质火山碎屑岩,矿体受断裂构造控制,呈NW向脉状展布,然而有关该矿床的成因类型、金属沉淀机制和成矿过程研究尚欠缺。本文针对该矿床开展详细矿相学和黄铁矿微量元素研究。结果显示,从早到晚,该矿床矿化过程可分为四个阶段:石英-黄铁矿阶段(S1)、石英-黄铁矿-赤铁矿阶段(S2)、石英-多金属硫化物阶段(S3)和石英-赤铁矿阶段(S4)。金主要以自然金的形式存在于S2和S4阶段中;S2阶段黄铁矿(Py2)明显富集Pb、Sb、Bi、W、V、Sc、U、Al和Ti等元素,不同阶段黄铁矿中不可见金含量均较低(均值0.8~1.7μg/g),As(均值517~931μg/g)与Au整体上正相关,局部存在解耦,微量元素变化主要受控于黄铁矿中不同类型矿物包裹体。综合地质特征、矿物组合、矿物结构、微量元素和热力学计算分析显示,该矿床为中硫型浅成低温热液矿床,流体沸腾和流体混合导致的氧逸度快速上升分别是S2和S3阶段自然金沉淀的关键因素,而黄铁矿中的不可见金主要受控于As对黄铁矿晶格的改变,局部受控于动力学过程控制的黄铁矿晶格缺陷。

满洲里-克鲁伦成矿带铁锰铅锌等多金属矿成矿规律

满洲里-克鲁伦成矿带于东北亚地区,是重要的多金属矿产资源集中区。通过对成矿带的地理位置和矿产资源的分布状况进行介绍,详细分析了成矿时代的3个主要阶段:新太古代-古元古代、晚古生代和中生代。其中中生代的成矿作用最为强烈。同时,通过探讨成矿带的地质构造特征,包括含矿建造特征、区域构造控矿作用、中生代火山构造以及岩浆侵入活动的控矿作用,总结了区域成矿模式,指出成矿带的金属成矿主要集中于中生代,并且成矿作用表现出多期次、多阶段性的特点。研究结果为理解该地区的成矿作用提供了新的视角,并对未来的地质找矿资源勘查工作提供了科学依据。