云南元阳大坪金矿铅同位素化探评价

通过对云南元阳大坪金矿某切穿矿脉剖面、不同海拔高程矿脉的矿石和围岩的铅同位素组成分析，采用铅同位素系统剖面化探方法对大坪金矿进行了化探评价和隐伏矿的预测分析，指出大坪金矿已进入主矿体的中心部位，深部隐伏矿潜力不大，找矿战略应以扩大横向为主。金矿化与闪长岩铅同位素组成的一致性，表明金矿化受闪长岩的控制。     

桂东地区金矿硫同位素地质特征及找矿意义

桂东地区发育三种成因类型的金矿,各类金矿的硫同位素组成有明显差异。本文计算了共生硫化物沉淀时的同位素平衡温度,并根据各类金矿的硫同位素组成特征,探讨了硫的来源,认为硫源应以深源重(同)熔岩浆热液为主,部分来自地层。同时还研究了硫同位素组成的空间变化规律及对矿床深部及外围的找矿意义。     

山东蓬家夼金矿硫铅碳氧同位素地球化学

位于山东胶莱盆地东北缘的蓬家夼金矿，受基底元古宙荆山群变质杂岩中的低角度层间滑动断层控制，金矿化类型属蚀变构造碎裂－角砾岩型。同位素地球化学研究表明，蓬家夼金矿硫同位素组成与胶东其它典型金矿相似，以富集^34S为特征，矿石硫一般稍高于老地层和中生代花岗岩的δ^34S值，反映大气降水循环淋滤作用使硫同位素发生了一定程度的分馏。铅同位素组成范围变化大，表现为异常铅特征。蓬家夼金矿床碳酸盐矿物碳氧同位素组成不同于胶东金青顶、三山岛等金矿，介于岩浆碳酸岩与荆山群大理岩范围之间，说明蓬家氚金矿的碳质来源于沉积碳酸盐岩和深源热液的混合。矿床地球化学特征显示了成矿物质的多源性，这与该矿床形成时所处的构造边缘环境有关。     

湘中锡矿山式锑矿成矿物质来源探讨

本文从地层含矿性，同岩浆活动的关系及同位素组成特征等几个方面进行分析，以阐明湘中锡矿山式锑矿成矿物质来源于构造岩浆活化作用形成的区域性深部上升流体，虽然赋矿层位相对集中，但不存在明显的锑矿源层，铅同位素研究表明矿石铅来源于深部均化条件下的铅同位素演化系统，与围岩地层铅同位素明显不同，硫同位素显示矿石硫为均一化程度较高的混合深源硫，包裹体水氢，氧同位素组成介于大气降水与初生水之间，为混合水类型。     

辽南地区金矿床铅同位素组成特征

辽南地区是我国重要的金矿化集中区,区内产出大、中,小型金矿２０余处。简要叙述了猫岭,五龙,四道沟,岫岩,新房５个金矿床的地质概况。讨论了它们的铅同位素组成并划分为两大类：第一类具有正常铅的同位素组成,其成矿年龄与辽河群变质年龄相当;第二类具有异常铅的同位素组成。在铅构造模式图上,上述５个金矿床铅同位素组成具有壳源铅的特点。     

哀牢山北段金矿带铅同位素特征研究

以哀牢山北段金矿带中最大金矿田──老王寨金矿田为例，从铅同位素组成，源区特征，单阶段模式年龄，铅源初始年龄及与墨江金厂矿石铅同位素对比等五个方面，结合图表解析，论述了金矿带的铅同位索特征，指出本区铅同位素组成是基本稳定的，且主要属造山带铅。从铅同位素一个侧面证实哀牢山北段金矿带矿化从燕山期到喜马拉雅期，且以喜马拉雅期矿化为主，参加矿化物质显示多期多阶段性的特点。     

田湾金矿成矿带成矿流体的同位素地球化学示踪

田湾金矿成矿带中 ,成矿流体同位素组成的复杂性 ,反映了成矿流体是多源的。石英流体包裹体氢氧同位素组成表明 ,成矿流体中的水主要来源于大气降水和岩浆水的混合。碳、氧同位素(δ13 C和δ18O)组成表明 ,既有沉积围岩中的碳 ,也有深部来源的碳 ,具有混合来源特征。成矿带内δ3 4S波动于 0‰～ 10‰之间 ,变化不大 ,具有深部来源硫的特征。大发沟矿段铅同位素组成变化较大 ,具有深、浅多源性。     

铅同位素在甘肃格尔珂金矿深部找矿中的应用与实践

铅同位素系统剖面化探方法及定量预测模型已经在铀矿床、铜矿床、金矿床和铅锌矿床(深部)找矿中得到了良好的应用和推广。将该方法和预测模型引入到大水金矿田格尔珂金矿(原称大水金矿)深部找矿研究中,并以其对格尔珂金矿12条勘探线的矿体进行了隐伏深度下限HL、隐伏系数R、隐伏资源量QB和富集系数K等模型参数的研究和预测,指示出研究区最佳深部找矿潜力区位于研究区西部,东部的深部找矿潜力最小,中部介于二者之间。最后,结合预测后近8年的实际生产数据和资料,将预测结果与生产实践做对比后表明:研究区的铅同位素定量预测模型构建正确,达到了预测效果,正确指导了研究区的深部找矿工作;在预测潜力最佳的研究区西部实现了深部找矿的重大突破,发现单是一个(Au2)矿体的隐伏资源量就能达到预测模型中全区的隐伏资源量,在研究区中部(Au111矿体)和西部(Au37矿体)也有比预测更大的潜力;用实际的生产实践数据和资料进一步提高了研究区的深部找矿潜力。该文为铅同位素方法在深部找矿中的应用提供了新的成功实例,并以实践资料补充、完善了铅同位素定量预测模型。     

北山南带金矿床(点)稳定同位素组成及找矿意义

通过对甘肃北山南带金矿床（点）稳定同位素组成特征的研究及水／岩交换理论提供的找矿信息，探讨了本区金矿床（点）的物质来源具多源性，但以壳幔混合型为主；矿源层形成于华力西中晚期，而燕山期是金的主要成矿期。提出钻井沟金矿点具找矿远景，其次为拾金坡；金沟子及花西山找矿意义不大。推测乌龙泉、老君庙金矿点和小西弓金矿床中带深部应有新的水／岩交换中心和盲矿体     

鲁西地区绿岩带金矿床铅同位素研究

在鲁西太古宙绿岩带中,分布有较多的绿岩带变生热液－构造蚀变岩型金矿,具有良好的找矿前景。从铅同位素组成来看,区内铅同位素变化较大,多为放射性成因铅质量分数较高的异常铅。所测同位素样品中,以黄铁矿铅同位素组成变化最大,是铅同位素在演化过程中受到放射性铀铅和钍铅不同程度混染的结果,多数样品单阶段模式年龄不具计时意义。计算表明,区内铅来源于ｕ＝９．２０,ｗ＝３７．４５,ｋ＝３．９５的源区,在５９５Ｍａ前     

Application of Lead Isotopes to Geochemical Exploration of Gold Deposits in Baoban , Hainan Province, China

Lead isotopes have been widely applied in geochemical exploration and evaluation of ore deposits, as well as in ascertaining the age of mineralization and the source of ore fluids.Long-term practice showed that the method of lead isotope targeting is somewhat efficient for macroscopic evaluation of forecasting areas, but not powerful enough for for ecasting concealed orebodies. As the contents of U and the variation of U/Pb ratio sharply decrease with depth in the lithosphere, U-Th-Pb isotopic differentiation must have occurred during the crust-mantle e-volution. Lead isotopic ratios show a wide variation range, varying in the front of mineralizationand shallow-derived ores, but maintaining very stable in the major orebody and being usuallyclose to the average isotopic composition of the crust and mantle of the continent block fromwhich the ores were derived. Therefore, the lead isotopic composition can serve as a measure for identifying the position of mineralization. The lead isotope geochemistry was applied to the ex-ploration and evaluation of the Baoban gold deposits of Hainan Province, China. The an alyticalresults of ore veins and adjacent rocks showed that there is a correlation between the lead isotopedata and the position of orebody. Based on the experience from the Baoban gold deposits and other ore deposits in Yunnan Province, an exploration principle has been established, that is,positive anomalies of lead isotope eigenvectors for prospecting deep-seated orebodies and nega-tive anomalies of eigenvectors for enlarging lateral exploration surrounding the known deposit.The ore beds in the Erjia and Beiniu mining districts should be as signed to the deep part of the orebody and those in the Tuwaishan mining district should be the shallow part, so ore beds cor-responding to those in the Erjia and Beiniu mining districts may be found in the Tuwaishan min-ing district.     

Assessment of geochemical anomalies for gold exploration using lead isotopes in west Hainan, China

Lead isotopic ratios and Pb contents have been measured along typical profiles across orebodies of the Baoban and Tuwaishan gold deposits on Hainan Island, China. These deposits are hosted by the middle to upper Proterozoic Baoban Group, which is composed of migmatite and extends for about 51 km on the hanging-wall side of the Gezhen Fault. The deposits have a common initial Pb isotopic ratio of ²⁰⁶Pb/²⁰⁴Pb = 18.683, but show distinctive variations within each deposit.The Pb isotopic ratios are more homogeneous in the orebodies and altered auriferous rocks than in the migmatite wall rocks. The richest orebody in the study area is known as the V1 orebody of the Baoban deposit; it has the lowest and most homogeneous ²⁰⁶Pb/²⁰⁴Pb ratio. This feature suggests that in this migmatitic area, it is possible to distinguish ores from barren wall rocks, and rich ore shoots from non-commercial mineralization, by their distinctive Pb isotopic ratios.A lower initial Pb isotopic ratio (²⁰⁶Pb/²⁰⁴Pb= 18.538) was measured in two other deposits, Beiniu and Erjia, which occur in the same migmatite and are controlled by the same fault as the Baoban and Tuwaishan deposits. Therefore, two metallogenic phases may have taken place, one at 85 Ma and the other at 170 Ma; these ages can be calculated using the Pb growth model of Cumming and Richards.The feasibility of evaluating geochemical anomalies through their Pb isotopic signatures was investigated by comparing the Pb isotopic ratios of B horizon soils from significant and non-significant anomalies with those obtained from the ores and alteration zone rocks. The results show that the Pb isotopic ratios in significant anomalies are consistent with those of the ores, whereas the signatures of non-significant anomalies are heterogeneous and rather different from those of the ores.Six unexplored anomalies have been evaluated using this criteria; five of them were found to be non-significant. One anomaly, however, presents the same signature as the Beiniu deposit, suggesting that it may be related to undiscovered ore close to the Gezhen Fault. Plans have been made to drill this target.     

北山地区照壁山金矿床地质特征及成因

照壁山金矿床是北山地区中部金矿集中区最具代表性的金矿床之一,金矿化主要在黑云母花岗岩株内或沿其与志留系公婆泉群火山-沉积岩的接触带产出,黑云母⁴⁰Ar-³⁹Ar同位素年龄为296±5 Ma.金矿体主要由含金石英脉,网脉和细脉浸染状块体组成,金属矿物主要有黄铁矿、方铅矿、闪锌矿、黄铜矿、自然金和银金矿,脉石矿物为石英和绢云母.围岩蚀变自含金矿脉(体)向外,分别为硅化、绢云母化和绿泥石化;另外,沿岩体与火山-沉积岩接触带常可观察到黄铁绢英岩化.微量元素和硫、氧、氢及铅同位素数据表明:黑云母花岗岩是同碰撞造山期深源岩浆与地壳物质相互作用的结果,成(岩)矿物质主要来自壳幔混合源,含矿热液是岩浆热流体与大气降水混合的产物.海西期花岗质岩浆活动不仅为金矿床的形成提供了物质和热力来源,而且是成矿热液对流循环的"发动机",成矿体系温、压降低是导致金沉淀与富集的重要控制因素.     

Re–Os and U–Pb Geochronology of the Erlihe Pb–Zn Deposit, Qinling Orogenic Belt, Central China, and Constraints on Its Deposit Genesis

The Erlihe Pb–Zn deposit is an important mine of the Pb–Zn metallogenic zone in the South Qinling Orogen. It has been considered a sedimentary exhalative deposit in previous investigations because the ore body occurs concordantly at the transitional location of an upright fold. Re and Os isotopic analyses for paragenetic pyrites with sphalerite and galena from the ore body have been used to determine the timing of mineralization and to trace the source of metallogenic materials. The Re–Os isotopic data of four pyrite samples construct an isochron, yielding a weighted average age of 226±17 Ma (mean square weighted deviation=1.7), which is considered the main mineralization age. A dioritic porphyrite vein sample, showing weaker mineralization, was also dated using the SHRIMP zircon U–Pb isotopic method to constrain the youngest metallogenic age of the ore deposit, because it distributes along a group of tensional joints cutting not only the upright fold in the deposit field, but also the main ore bodies. The dioritic porphyrite sample yields a weighted mean 206Pb/238U age of 221±3 Ma, which is slightly younger than the Re–Os isotopic isochron age of the pyrites, considered as the upper age limit of the mineralization, namely the ending age of the mineralization. The Os isotopic compositions of sulfide minerals distribute within a range between Os isotopic compositions of the crust and the mantle, indicating that the ore deposit can be derived from magma-related fluid, and the metallogenic materials are most likely derived from the mixing source of the crust and the mantle. The Erlihe Pb–Zn deposit and associated dioritic porphyrite vein, important records of Qinling tectonic–magmatism–mineralization activities, were formed during the Triassic collisional orogeny processes.     

西藏甲玛铜多金属矿床流体､成矿物质来源的地球化学约束

甲玛铜多金属矿是西藏冈底斯成矿带中东段勘查程度最高、成矿元素与矿体类型复杂的超大型斑岩-矽卡岩型矿床。前人在控岩-控矿构造、矿床地质、地球化学、矿床模型等方面已经完成了大量的研究工作,但对于矿床成矿机制研究方面尚存不足,特别是流体、成矿物质的来源方面欠缺系统的研究工作和对资料的全面梳理。文章在大量阅研和总结前人研究资料的基础上,以矿区16号勘探线作为典型剖面开展了氧同位素填图,同时对硫同位素进行了必要的样品补充采集。通过综合研究,有证据表明甲玛矿区深部隐伏斑岩体存在岩浆流体的出溶,在此基础上,氢、氧同位素组成表明矿化由早到晚演化过程中,流体由岩浆水向大气降水增加方向演化;同时,氧同位素填图以及流体包裹体平面均一温度分布确定成矿流体源位于矿区zk1616~zk3216一带。此外,S、Si同位素组成均表明了矿区成矿物质主要来源于成矿岩浆岩,而铅同位素的研究进一步说明成矿物质主要来源于冈底斯后碰撞环境下因地壳减薄、地幔上涌导致的壳幔混合作用。文章依据地球化学的研究成果,探讨矿床流体、成矿物质的来源,为甲玛矿床成因、成矿机制研究夯实基础。     

Isotope Tracing and Prospecting Assessment of Gold-Silver Deposits in Zhejiang Province

Three different types of gold and silver deposits in Zhejiang Province(Huangshan gold deposit, Zhilingtou gold-silver deposit and Haoshi silver deposit) showmarked differences in lead and strontium isotopic composition, suggesting three differentsources and geneses of these deposits. The Huangshan gold deposit features low initial Srisotope ratios and low μ values or low content of radiogenic Pb and its ore-forming materialscame primarily from the upper mantle; the Zhilingtou gold-silver deposit shows high initial Srisotope ratios and high μ values or high content of radiogenic Pb and the ore-forming materialswere derived mainly from the upper crust; and the Haoshi silver deposit has its Pb and Srisotope ratios between the above two cases with the ore-forming materials stemming from boththe mantle and the crust. The characteristic Pb isotopic composition may serve as an indicatorfor prospecting for different types of ore deposits.     

柴北缘赛坝沟金矿床硫、铅同位素组成:对成矿物质来源的指示

柴北缘赛坝沟金矿床是青海省赛什腾山-阿尔茨托山成矿带上重要的岩金矿床,成矿地质条件优越.矿体赋存于北西-北北西向韧-脆性断裂构造组内,呈脉状、透镜状,构造控矿作用明显,矿石类型分为石英脉型和蚀变糜棱岩型.热液成矿期可划分为4个阶段:Ⅰ少量黄铁矿-烟灰色石英阶段、Ⅱ金-黄铁矿-乳白色石英阶段、Ⅲ多金属硫化物-金-灰白色-...     

云南迪庆春都斑岩铜矿床同位素地球化学

春都铜矿床为近年来新发现的斑岩型铜多金属矿床,矿体主要赋存于花岗闪长斑岩及岩体与圈岩接触带内.文章对春都斑岩铜矿床的同位素地球化学进行研究,分析表明:硫同位素组成具幔源硫特征,硫主要来源于深部岩浆,同时有少量地壳沉积物还原硫的混入;铅同位素组成具有壳、幔混合源特征,主要来自于下地壳或上地幔.成矿流体以原始岩浆水为主,同...     

内蒙古甲乌拉大型Pb-Zn-Ag矿床稳定同位素地球化学研究

内蒙古甲乌拉银多金属矿床位于大兴安岭成矿带北段,为近年来发现的大型银铅锌多金属矿床。矿床矿体分布完全受到断裂构造的控制,金属矿物组成主要为方铅矿、闪锌矿、黄铜矿、黄铁矿、磁黄铁矿、毒砂、辉钼矿及磁铁矿等。文中重点分析了矿床的硫、氢、氧、碳和铅稳定同位素地球化学特征。研究结果表明：金属硫化物δ34S集中为1.37‰~4.10‰,平均为3.10‰(n=13),极差为2.73‰;石英和方解石δ18Owater的变化范围较大(-18.96‰~+1.08‰) (n=9),均值为-11.36‰;δDV SMOW的变化范围比较集中(-133.6‰~-103.4‰) (n=9);27件样品的铅同位素组成为：206Pb/204Pb=18.228 3~18.758 7、207Pb/204Pb=15.457~15.880和208Pb/204Pb=37.841~39.049,矿床的铅组成基本为正常的放射性成因铅;方解石δ13CV PDB变化范围为-5.2‰~-8.4‰,平均为-6.8‰(n=2)。矿石硫化物的硫同位素及方解石的碳同位素均指示成矿物质可能来源于深部的岩浆活动;石英和方解石的氢氧同位素组成表明成矿流体早期以岩浆流体为主,成矿晚期加入了大量加热补给的大气降水;铅同位素组成表明成矿流体中铅的来源主要为幔源,矿床形成过程中混入少量的壳源铅。矿床稳定同位素组成显示成矿流体主要来源于深部的岩浆热液,特别与燕山晚期的火山次火山热液有较为密切的联系,在流体演化过程中大气降水的加入对矿床成矿元素的聚集和沉淀也起到有利作用。成矿作用的发生是在一种总硫浓度比较低、中等氧化环境、相对开放的非平衡体系中进行的。矿床形成的地球动力学背景为一种岩石圈大规模快速减薄的过程。甲乌拉大型Pb Zn Ag矿床的成因类型属于火山次火山热液脉状银多金属矿床。     

内蒙古东部闹牛山铜矿成矿地质背景分析

通过对闹牛山铜矿区与成矿有关的次火山岩岩石化学分析，以及对矿区火山一次火山岩微量元素、稀土元素的分析，结合相关的铅同位素分析，综合分析了该矿床的成矿地质背景。认为：闹牛山铜矿床构造环境属于大陆边缘裂陷带的局部隆起区，成矿火山岩浆为钙碱性，其来源于地壳深部或上地慢，并有上部地壳物质混染。