试析地幔来源物质成矿域——以中亚造山带为例

文章总结了大量的Sr,Nd,S,Pb多元同位素资料，据此认为，中亚造山带的铜，金多金属矿床与区域花岗岩在形成时代和物质来源上基本吻合，具有一定的继承性，从古生代直至中生代，地幔来源物质参与了成岩成矿作用，即便是钨、锡稀有金属矿床，也受到地幔来源物质的明显影响，从而揭示了地幔来源物质在中亚造山带金属成矿作用的重要意义。     

中亚造山带天河石花岗岩及相关铷矿床的主要特征与研究进展

铷是重要的"关键金属"矿产资源,是未来各国资源争夺的焦点。虽然我国铷矿资源总量丰富,但主要为低品位难以加工利用的花岗岩型铷矿床,而以铁锂云母、锂云母和铯沸石等作为矿石矿物的高品位易加工花岗伟晶岩型铷矿床非常有限。因此,富铷花岗岩及相关铷矿床的形成过程、元素分异机制以及铷在不同矿物相中的赋存状态和控制因素是铷矿床成矿机制研究和找矿工作的关键。本文在对花岗(伟晶)岩铷矿主要研究进展进行综述的基础上,简介中亚造山带东、西段典型天河石花岗岩及相关铷等稀有金属矿床的主要特征和时空分布,并对未来研究重点进行了展望。本文认为,中亚造山带是全球最重要的天河石花岗岩和相关稀有金属矿床成矿域,其西段大量发育三叠纪天河石花岗岩,而东段大量发育晚侏罗至早白垩世天河石花岗岩。两者形成时代和构造背景分别与古亚洲洋向古特提斯洋构造域,以及古亚洲洋向古太平洋构造域的巨大转折相对应,铷等稀有金属成矿潜力巨大,值得开展深入的年代学、岩石学和矿床成因研究。     

Late Permian–Triassic metallogeny in the Chinese Altay Orogen: Constraints from mica 40Ar/39Ar dating on ore deposits

The Central Asian Orogenic Belt (CAOB) constitutes the largest Phanerozoic accretionary orogen on Earth. It extends over 5000 km and hosting numerous metal deposits. The Chinese Altay Orogen, an important element of the CAOB, hosts abundant Devonian (ca. 410–370 Ma) deposits. The ⁴⁰Ar/³⁹Ar dating of seven mica separates from the representative samples syngenetic with orogenic-type mineralization is summarized to record a poorly studied Permian to Triassic metallogenic episode in the Chinese Altay Orogen. The Kelan and Maizi basins in the Chinese Altay Orogen, which likely represent an arc accretionary complex, contain a series of polymetallic lode deposits hosted in low-grade metamorphic volcano–sedimentary rocks. Two muscovite and five biotite separates were obtained from the ore-forming veins paragenetically associated with Au-bearing polymetallic sulfides in the Keketale Pb–Zn, Wulasigou Cu, Tiemurt Pb–Zn, Dadonggou Pb–Zn and Sarekuobu Au deposits. These separates yielded ⁴⁰Ar/³⁹Ar plateau ages ranging from 260 Ma to 205 Ma. Integration of these results with other published geological and geochronological data indicates that the Au–Cu–Pb–Zn mineralization post-dated the final CAOB assembly, with fluid movement and mineralization possibly driven by regional metamorphism and deformation. It is herein proposed for a metallogenic model that the metamorphic fluid migration following final assembly of the CAOB results into the formation of the deposits.     

北山地区中生代岩浆活动与成矿构造背景分析

中亚造山带是古亚洲洋演化与最终消亡的产物。北山地区处于该造山带中段南部,是中国重要的铜、钼、金、铁多金属成矿带。北山地区在晚古生代—早中生代曾发生过2次碰撞造山作用,一次发生于晚古生代末,与古亚洲洋的最终闭合有关;另一次发生于早中生代三叠纪,与北山南带发育的石炭纪一二叠纪裂谷封闭有关。因此,从时间演化看,中生代三叠纪北山地区为碰撞-碰撞后造山阶段,发育大规模剪切带和强烈的岩浆活动及伴生的金属成矿作用。北山地区中生代岩浆活动以深成侵入相发育并缺失相应的喷出相为特征;岩石类型以中酸性侵入岩为主,基性侵入岩局部可见,S、I、A型花岗岩均有产出。与中生代岩浆活动有关的矿床类型主要包括与I-A型花岗岩伴生的斑岩钼矿床、与S型花岗岩伴生的钨(锡)矿床、与中酸性侵入体有关的矽卡岩型金、银铜铅锌多金属矿床和与中酸性侵入体有关并受剪切带控制的金矿床。中生代印支期是该地区最晚一次大规模岩浆活动与金属成矿时期,其发育的范围、规模和强度均比原来认识的要广泛的多,值得进一步关注。     

Ordovician Intrusive-related Gold-Copper Mineralization in West-Central New South Wales, Australia

Three major types of Ordovician intrusive-related gold-copper deposits are recognized in central-west New South Wales, Australia: porphyry, skarn and high sulphidation epithermal deposits. These deposits are mainly distributed within two Ordovician volcano-intrusive belts of the Lachlan Fold Belt: the Orange-Wellington Belt and the Parkes-Narromine Belt. Available isotopic age data suggest that mineralization of the three types of deposits is essentially coeval with the Ordovician intrusive rocks (480-430 Ma).Porphyry gold-copper deposits can be further divided into two groups. The first group is associated with monzonite showing shoshonitic features, represented by Cadia and Goonumbla. The second group is associated with diorite and dacite, including the Copper Hill and Cargo gold-copper deposits. Gold skarn is associated with Late Ordovician (430-439 Ma) monzonitic intrusive complexes in the Junction Reefs area (Sheahan-Grants, Frenchmans, and Cor-nishmens), Endeavour 6, 7 and 44, Big and Little Cadia     

新疆北部VMS矿床地质特征及成矿规律

VMS矿床是中亚造山带的重要矿床类型,在新疆中亚造山带（即新疆北部）主要分布于阿尔泰和东天山的阿舍勒、克兰、麦兹和卡拉塔格矿集区.含矿层位主要有下?中志留统红柳峡组、上志留统?下泥盆统康布铁堡组下亚组和上亚组、下?中泥盆统阿舍勒组和下石炭统小热泉子组海相火山沉积岩系.矿区发育喷流岩,如含铁碧玉岩、重晶石、硅质岩、铁锰质大理岩、黄铁矿层、绿泥石岩.VMS成矿系统中发育多种矿化类型,“双层结构”（层状或透镜状矿体和补给通道相脉状矿体）是其中之一,还有与火山热液有关的脉状矿化、与次火山热液有关的脉状和浸染状矿化.VMS矿床形成于3个成矿期,即早?中志留世（428~438 Ma）、早?中泥盆世（379~413 Ma）和早石炭世（332~359 Ma）.硫来自下伏火山岩、海水硫酸盐无机还原作用和硫酸盐细菌还原作用.成矿流体以中低温（300~120 ℃）低盐度（2%~10% NaCl_eq）为特色,成矿流体为深循环海水混合不同比例的岩浆水.VMS成矿系统中由于受火山机构、岩相、矿化类型、矿化部位、成矿流体来源、物理化学条件等因素影响,造成了成矿元素组合复杂.      

Triassic magmatism and Mo mineralization in Northeast China: geochronological and isotopic constraints from the Laojiagou porphyry Mo deposit

The Laojiagou Mo deposit is a newly discovered porphyry Mo deposit located in the Xilamulun Mo metallogenic belt, Northeast China. Mo mineralization mainly occurred within the monzogranite and monzogranite porphyry. Re–Os isochron dating of molybdenites indicate a mineralization age of 234.9 ± 3.1 Ma. Zircon LA–ICP–MS U–Pb analysis for monzogranite porphyry and monzogranite yield ²⁰⁶Pb/²³⁸U ages of 238.6 ± 1.8 and 241.3 ± 1.5 Ma, respectively, indicating that Laojiagou Mo mineralization is related to Middle Triassic magmatism. Hf isotopic compositions of zircons from both monzogranite porphyry and monzogranite are characterized by positive ε_Hf(t) values [ε_Hf(t) = 2.9–7.3 and 1.5–7.9, respectively] and young T_DM2 model ages, which implies that the magma was derived from juvenile crust created during accretion of the Central Asian Orogenic Belt (CAOB). Identification of the Laojiagou Mo deposit adds another important example of Triassic Mo mineralization in the Xilamulun Mo metallogenic belt where most Triassic Mo deposits in northeast China cluster around the northern margin of North China Craton. Based on the regional geological setting and geochronological and Hf isotope characteristics, we propose that Triassic Mo deposits and related magmatic rocks in northeast China formed during the last stages of evolution of the CAOB. These deposits formed during post-collisional extension after the closure of the Palaeo-Asian Ocean and amalgamation of the North China–Mongolian Block with the Siberian Craton.     

Geochemical studies on REE and trace elements from several Cu-Au deposits along the lower Yangtze metallogenic valley, central-southern Anhui Province

The Yangtze Valley was one of the most important metallogenic regions during the Jurassic-Cretaceous period in East China, where more than 200 polymetallic Cu-Fe-Au, Mo, Zn, Pb, Ag deposits have been found. Trace elements were chemically analyzed and the relevant data were collected from literature for the Yanshanian (Mesozoic) igneous rocks which have close relationship with Cu-Au mineralization. Copper mineralization in the lower Yangtze Valley can be divided into three major types: skarn type, porphyry type and volcanic type. The porphyry type is of rare occurrence, such as the Shaxi porphyry copper deposit in the northern part of the lower Yangtze metallogenic valley. This paper focuses on the REE and trace element geochemistry of several Cu-Au deposits along the lower part of Yangtze metallogenic valley in Anhui. The results showed that there are differences in REE distribution for these four types of Cu-Au mineralization, which confine the sources of REE and trace elements as well as other mantle and transitional compatible elements. The results of both REE and trace element geochemical studies showed that these elements with different characteristics have different origins, probably representing different sources of Cu-Au deposits in the deep crust and upper mantle environments. The 40Ar/39Ar dating of one biotite sample gave an age of 131 Ma with a high level of confidence, which represents the age of formation of the Shaxi porphyrite intrusive with porphrytic Cu-Au mineralization, which is consistent with that of the majority of the adjacent acid intrusives with mass Cu-Au mineralization along the Yangtze metallogenic belt in the Yanshanian period (Mesozoic). This is the first attempt to use the high precision method to date the Shaxi porphyrite intrusive.     

Association of pyrobitumen with copper mineralization from the Uchumi and Talcuna districts,central Chile

Pyrobitumen has been shown to be an essential component in formation of some Chilean manto-type (strata-bound) copper deposits and its presence has been observed in a number of other deposits but has received limited investigation. In this paper we present paragenetic and geochemical data from two central Chilean manto-type deposits from the Uchumi and Talcuna districts where solid pyrobitumen (residual petroleum) is intimately associated with copper sulfides.Pyrobitumen in the Uchumi deposit occurs in pore space within the host conglomerates and is adjacent to a granitoid stock; pyrobitumen predates bornite–chalcocite mineralization and may have reduced subsequent mineralizing fluids. Pyrobitumen from the Manto Delirio deposit, Talcuna District, fills the cores of early sphalerite veins and was partially replaced by later Cu–As mineralization; pyrobitumen is petrographically intergrown with Cu–Fe sulfides and light δ¹³C values of gangue calcite indicates the interaction of pyrobitumen with the mineralizing fluid.The presence of pyrobitumen within the ores of other manto-type copper deposits in the Lower Cretaceous basin of Chile suggests that degraded petroleum reservoirs, in particular if biodegradation generated authigenic pyrite, can be important controls for metallic mineralization derived from hydrothermal solutions of different sources.     

新疆伊吾县北山金矿区次火山斑岩型隐伏金矿预测研究

北山金矿区成矿地质条件十分有利，与华力西晚期陆相火山-港火山作用有关的蚀变、矿化广泛发育。已有资料证明，矿区东部脉状蚀变岩型金矿化具有一定工业意义。近年来在矿区西部又发现了较大规模呈面型特征的物探高相位电性异常及叠加于其上的化探原生晕Au、As、Sb异常。初步的地质与物、化探综合评价工作证实，矿区西部具有寻找次火山斑岩型隐伏金矿的潜在远景。     

重晶石成矿地质特征、成矿作用及成矿机制

重晶石全球范围内广泛分布,重晶石矿床具有形成时代多、元素来源复杂、成矿作用多样等特点,目前有关重晶石矿床的成因仍存在争议。文章系统分析前人的研究成果,厘定了不同类型的典型矿床、成矿时代规律,探讨了不同类型矿床中成矿元素来源、成矿作用及成矿机制。矿床类型方面,重晶石矿可分为沉积型、岩浆热液型、层控型、火山-沉积型和风化（残积）型,主要分布在特提斯成矿域和劳亚成矿域,其他地区主要是冈瓦纳成矿域和环太平洋成矿域,其中沉积型是最主要的成矿类型,占重晶石矿床的60%以上。成矿时代方面,重晶石的成矿时代主要为古生代和中生代,赋矿岩系以沉积岩为主,其次为岩浆岩。成矿物质来源方面,全球典型重晶石矿床中的S同位素和Sr同位素显示,成矿物质来源具有多源性、多样性、差异复合性等特点。成矿机制方面,重晶石的成矿机理复杂,具有多阶段性、多因素等特点。     

兰坪—思茅盆地红层铜矿成矿规律

兰坪—思茅地洼盆地中新生代红层铜矿可分为三个成因类型:沉积型,沉积-改造型和改造型。它们呈“层—梯”式产出。在成因上与热卤水活动有关。在分布上受澜沧江断裂和中轴断裂控制。微量和稀土元素及同位素地球化学研究表明,成矿物质以壳源为主。成矿热动力与成矿期区域性幔热异常和强烈的构造活动有关。矿床形成于两个时期,即地洼初动期的沉积—成岩矿化期(T_3-E_1)和地洼激烈期的改造成矿期(E_2)。其中,改造成矿是本区铜矿最重要的成矿过程。     

西南三江碰撞造山带沉积岩容矿Pb-Zn-Ag-Cu贱金属复合成矿与深部过程

西南三江特提斯造山带中新生代沉积盆地中(沱沱河、玉树、昌都和兰坪-思茅地区)发育包括金顶超大型铅锌矿床在内的一系列以沉积岩容矿的Pb-Zn-Ag-Cu贱金属矿床,构成长达千余千米的青藏高原东缘贱金属成矿带。作为大陆碰撞环境成矿谱系的重要矿床类型,加强这些矿床的理论研究对提高和完善大陆碰撞造山成矿理论和指导找矿勘查等具有重要意义。已有研究表明这些Pb-Zn-Ag-Cu矿床的分布受盆地形成后新生代大型逆冲推覆-走滑构造控制,其容矿岩石和成矿作用特征与SEDEX和MVT矿床存在明显的差异,矿床成矿流体表现出多来源混合的特征,成矿与深部过程密切相关。尽管取得重要进展,但由于缺乏高精度年代学数据制约,成矿动力学背景及其与碰撞造山的时空联系存在较大争议。一些矿床的研究显示复合成矿迹象,但是复合成矿过程与深部驱动等问题仍不清楚。近年来我们以兰坪和昌都盆地的Pb-Zn-Ag多金属矿床和Cu多金属矿床为重点研究对象,系统开展了成矿年代学、成矿流体源-运-储系统和复合成矿机制以及深部过程对成矿制约等方面研究。结果表明,兰坪盆地西缘Cu(Mo)多金属矿床主要形成于48～58Ma,兰坪和昌都盆地Pb-Zn-Ag多金属矿床主要形成于27～33Ma。成矿流体表现出明显的多来源混合的特征,主要存在三种类型:1)变质流体与盆地卤水或大气降水复合成矿,以金满-连城Cu矿床为代表; 2)盆地卤水与大气降水复合成矿,以金顶Pb-Zn矿床为代表; 3)盆地卤水和岩浆流体复合成矿,以拉诺玛Pb-Zn-Sb矿床为代表。兰坪盆地西缘Cu矿床主要形成于新生代印度-欧亚大陆主碰撞挤压阶段,与成矿密切相关的变质流体可能来源于陆-陆碰撞俯冲引起的高压变质。Pb-Zn矿床主要形成于印度-欧亚大陆晚碰撞构造转换环境,构造挤压和造山隆起驱动盆地流体迁移,同期的岩浆活动主要为成矿提供热驱动力或成矿物质。     

四川九龙县里伍铜矿包裹体研究

成矿物质来源是矿床研究的重要内容。本文通过里伍铜矿含矿岩石中的石英流体包裹体的温度、成分和盐度测试分析,以及矿床地球化学特征研究,结合区域地质演化历史,揭示其成矿物质来源、成矿物质的运移和浓集机制,为解释里伍铜矿的成矿环境和成因提供依据。     

西天山卡特巴阿苏金矿床成矿年代学及其地质意义-来自绢云母~(40)Ar-~(39)Ar同位素年龄证据

新疆卡特巴阿苏金矿床是近年来在西天山地区新发现的一个大型金矿床。该矿床大地构造位置处于塔里木板块和哈萨克斯坦-准噶尔板块结合部位的那拉提构造-岩浆岩带,其金矿体主要赋存于蚀变二长花岗岩内。为了确定金矿化的形成时代,对该矿床主成矿阶段与金矿化密切相关的蚀变绢云母开展了40Ar-39Ar同位素定年测试。绢云母40Ar-39Ar坪年龄为(268.56±1.8)Ma,正等时线年龄为(268.38±2.2)Ma,反等时线年龄为(268.52±2.2 Ma),三者在误差范围内一致,测试结果可信,可代表卡特巴阿苏金矿化的形成年龄,这也是首次对该矿床成矿年龄的精确限定。对比中亚造山带典型金矿床,卡特巴阿苏金矿床是西天山二叠纪后碰撞构造环境下岩浆流体活动的产物,矿床成因属与中温岩浆热液有关的构造蚀变岩型矿床。     

新疆北部弧-盆转化体系下铁氧化物-铜-金矿床的流体演化特征:来自卤族元素和稀有气体同位素的证据

东准噶尔北缘和东天山雅满苏带是中国新疆北部地区两个重要的晚古生代铁氧化物-铜-金矿化潜力区,以老山口、乔夏哈拉和黑尖山矿床作为典型矿床代表。研究表明两区域的铁氧化物-铜-金矿床均产出于盆地闭合的弧盆转化体系下,且具有明显的铁、铜-金两阶段矿化。卤族元素和稀有气体同位素作为可靠的流体示踪剂,被应用于探究这一特定构造环境下的铁氧化物-铜-金矿床的流体演化和矿床成因。结果显示老山口、乔夏哈拉和黑尖山矿床的成矿流体具有明显的混合流体端员特征:(1)岩浆流体端员,主要参与黑尖山矿床磁铁矿阶段,I/Cl、Br/Cl和⁴⁰Ar/³⁶Ar比值分别为(16.3~18.0)×10^-6、(1.03~1.06)×10^-3和352~437;(2)海水表源蒸发成因盐卤水端员,主要参与老山口矿床铜-金矿化阶段,I/Cl、Br/Cl和⁴⁰Ar/³⁶Ar比值分别为(77.1~87.7)×10^-6、(1.53~1.80)×10^-3和672~883;(3)蒸发岩溶解或者深度水-岩反应成因的盐卤水/沉积岩地层水端员,主要参与到老山口、乔夏哈拉矿床的磁铁矿阶段以及黑尖山、乔夏哈拉矿床的铜-金矿化阶段,综合I/Cl、Br/Cl和⁴⁰Ar/³⁶Ar比值分别为(477~26 301)×10^-6、(0.39~1.28)×10^-3和288~510。明显的多阶段矿化和铜-金矿化阶段以非岩浆富Ca高盐度卤水为主的特征与世界范围内的IOCG型矿床极为相似,表明新疆北部的铁氧化物-铜-金矿床应为IOCG型矿床。     

青海祁漫塔格地区牛苦头矿床和卡而却卡矿床B区花岗质岩石LA-ICP-MS锆石U-Pb年龄——对泥盆纪成岩成矿作用的指示

牛苦头矿床和卡而却卡矿床是青海祁漫塔格地区重要的多金属矿床。利用LA-ICP-MS锆石U-Pb法测得牛苦头矿床花岗闪长岩成岩年龄为394.0±1.3Ma,卡而却卡矿床B区黑云母二长花岗岩的成岩年龄为406.4±4.2Ma。这些年龄与区内野马泉、乌兰乌珠尔及夏日哈木矿床成矿岩体的形成时代范围基本一致,说明青海祁漫塔格地区早、中泥盆世可能发生了大规模的岩浆作用和与之有关的成矿作用。结合区域地质特征和已发表的地质年代学及岩石地球化学数据可知,青海祁漫塔格地区早、中泥盆世处于后碰撞伸展的构造背景,暗示早、中泥盆世可能是青海祁漫塔格地区又一个重要的多金属成矿期。     

内蒙古中东部油房西Pb-Zn-Ag多金属矿床辉钼矿Re-Os同位素年龄及地质意义

油房西Pb-Zn-Ag多金属矿床为近年来在兴蒙造山带内发现的中型脉状矿床,伴生Cu和Mo。该矿床主要产出于潜火山机构外侧的断裂系统内,与潜火山活动有明显的空间关系。成矿作用可以划分为3个阶段,即:早期钼矿化阶段;主成矿期铅、锌和银矿化阶段,伴生铜;晚期碳酸盐化阶段。早期钼矿化阶段,细脉浸染状钼矿化主要产出于潜火山相的花岗斑岩内,矿化较弱,伴随轻微的钾化和强烈的硅化和黄铁矿化,后期叠加了强烈的泥化;主成矿阶段,主要形成脉状闪锌矿、方铅矿、黄铁矿以及次要的黄铜矿化,以脉状充填产出于围岩裂隙内,围岩蚀变主要为硅化,局部有强烈的萤石化;晚期碳酸盐化阶段,主要发生绿泥石化和碳酸盐化。为进一步查明油房西矿化区成矿作用发生的时间,文章对矿床早期钼矿化阶段形成的辉钼矿开展了Re-Os同位素分析,4件样品分析结果获得的模式年龄加权平均值为(138.4±1.2)Ma,MSWD值为0.63,等时线年龄为(136.4±4.9)Ma。结果表明油房西地区Pb-Zn-Ag多金属矿床形成时间为早白垩世,属燕山期构造-岩浆活动的产物。     

塔里木和中亚造山带西段二叠纪大火成岩省的两类地幔源区

对塔里木和中亚造山带西段二叠纪玄武质岩石地质、年龄、元素地球化学、同位素组成的系统总结表明,二叠纪火成岩在分布面积、岩石类型(以玄武岩占绝对优势)、活动时间(以275Ma左右为峰期)等方面均与世界典型的大火成岩省一致,将其命名为巴楚大火成岩省(Bachu LIP)。元素和同位素地球化学特征表明,塔里木玄武岩来自长期富集的岩石圈地幔,来源深度为60～80km。塔里木基性岩墙和超镁铁-镁铁杂岩的原始岩浆可能来自软流圈地幔(OIB)部分熔融。中亚造山带西段的玄武岩、基性岩墙和超镁铁-镁铁杂岩主要来自被俯冲带熔体交代的强烈亏损的岩石圈地幔,其中部分地区可能有软流圈物质的加入,如东天山和阿勒泰南缘高Ti系列的玄武质岩石。根据元素和同位素地球化学资料,将巴楚大火成岩省分为2个地幔省(mantledomain),即塔里木省和中亚省。这2个不同地幔省的成矿系列也有显著的差异,塔里木省为钒-钛磁铁矿矿床,而中亚则以铜-镍-(铂族金属)硫化物矿床为主,成矿作用的差异和岩浆地幔源区的差异是完全对应的。综合地质、地球化学和成矿作用,认为巴楚大火成岩省的形成和二叠纪地幔柱密切相关。     

Pb Isotope Study of Some Nonferrous Metallic Deposits in China

Based on Pb-Pb isochron data of more than 40 Precambrian polymetallic deposits, the authors consider that there are four mineralization periods for the Precambrian copper deposits in China, and the major copper deposits were formed at about 1800 Ma; there are three mineralization periods for gold deposits formed from Archaean to Proterozoic. By studying hundreds of lead isotope data from some Mesozoic continental subvolcanic Cu and Ag polymetallic deposits and fine-disseminated gold deposits, the authors found that the calculation based on the lead single-stage evolution model or two-stage evolution model cannot give the true ore-forming ages but can provide more information about mineralization and material sources of the deposits.