表生异极矿成因研究及其找矿意义

云南金顶异极矿产于铅锌矿床氧化带中,基于对该矿床异极矿产出特征、颜色环带、不同颜色环带的成份、显微结构以及其他铅锌氧化物的分析,认为异极矿是由硅酸与锌的重碳酸盐溶液反应生成。镜下异极矿集合体纤维交织结构、环带结构、毛粘状结构等显微结构特征分析表明异极矿是表生环境下形成。扫描电镜获得异极矿清晰的单晶体、集合体和晶体间充填物的图像,晶体大小约为100μm～300μm,晶体间片状充填物约为250μm。同时对云南金顶铅锌矿床和异极矿与其他地区铅锌矿床和异极矿产出特征进行比较认为：异极矿一般产出于铅锌矿床表生氧化带,在风化淋滤作用较强环境下产出,对矿床环境和原生铅锌矿床找矿有一定指示意义。     

云南金顶铅锌矿床硫化物电子探针分析及其对矿床成因的指示

金顶铅锌矿床位于滇西兰坪思茅盆地北部,为世界级超大型铅锌矿床.应用电子探针分析(EPMA)技术测定了金顶铅锌矿床中不同矿段(北厂、跑马坪、白草坪)黄铁矿、闪锌矿的微量元素组成,探讨金属硫化物的地球化学特征、矿床成矿环境,从而为研究区矿床成因提供依据.结果表明,各个矿段不同寄主岩石中黄铁矿相对富集Pb、Zn、Co,贫Cu...     

金顶铅锌矿床地质特征及成因探讨

金顶铅锌矿床以陆相碎屑岩为主岩，明显区别于以海相碳酸盐岩为主岩的MVT矿床；其成矿背景、矿体产状及ωPb／ωZn都与SST铅锌矿床有较大差异；金顶铅锌矿床与SEDEX矿床相比，在矿体产状、金属—矿物分带、矿体上下盘特征以及接触界线上均存在一定差异。矿床特征的研究发现，金顶铅锌矿床上有盖层，下有遮档层，中间为孔隙度、渗透率较好的储集层，这一岩套组合类似于油气的生成，而穹窿、F2断层形成的构造空间则为成矿流体的贮集、沉淀和成矿提供了条件。     

云南金顶铅锌矿碳、氧、硫同位素地球化学特征及其地质意义

本文对金顶铅锌多金属矿床矿石中硫化物硫同位素及碳酸盐胶结物中碳、氧同位素进行了研究分析,结果表明:成矿流体中的CO2与沉积有机物和海相碳酸盐岩有关,源自碳酸盐岩热解作用和去碳作用以及沉积有机物的氧化作用和脱羧基作用。矿床的矿石矿物组成反映了成矿环境为高氧逸度环境。硫同位素特征研究表明:矿床中石膏矿体中的硫可能来自三叠系古大洋硫酸盐矿物。而金属硫化物矿物中的硫具有多源性,其主要来源为生物或细菌还原地层中膏盐(石膏、硬石膏、有机质等)的还原硫、壳源硫和有机硫。同位素研究表明金顶铅锌多金属矿的成矿物质应源自地壳。     

坡缕石晶体化学和成因研究现状与进展

综述了坡缕石(凹凸棒石)矿物晶体化学和成因研究的新进展和存在问题,最新研究表明:坡缕石是分布广泛很有成因意义的标型矿物。还着重介绍了我国坡缕石石棉和苏皖一带坡缕石晶体化学研究以及坡缕石成因研究的新成果和存在问题。     

滇西兰坪金顶特大型锶矿矿床地质特征及矿床成因探讨

云南兰坪金顶锶矿位于"三江"银铜铅锌多金属成矿区的兰坪金顶超大型铅锌矿区。矿区处于较为特殊的推覆构造中,推覆构造形成上三叠统三合洞组灰岩组成的推覆体叠置于白垩系和古新统云龙组之上,形成金顶穹隆,围绕金顶穹隆,无论是铅锌矿、锶矿,还是石膏矿矿体均呈板状、脉状、透镜状产在主推覆构造面下的景星组和云龙组陆相碎屑岩中。通过对锶矿床的地质特征、矿体特征研究,认为该矿床是沉积—热卤水构造动力改造型。     

金顶铅锌矿床相关地质问题及成因探讨

云南兰坪金顶超大型铅锌矿，同时也是大型黄铁矿、大型石膏和天青石矿，对其成因存在较大的分歧，主要有热液充填交代型、层控后生型矿床、同生沉积矿床和喷流(热水)沉积矿床等观点，尤以喷流(热水)沉积矿床占主导地位。实际上，要分析矿床的成因，探明其相关的地质问题，如矿区地层和沉积相、赋矿层位和灰岩角砾岩的成因等是至关重要的，也是研究和讨论该矿床成因和类型的前提条件。在大量充分搜集前人的研究成果基础上，结合野外的实际考察和室内综合研究，对在研究矿床成因时不可忽视的一些地质问题进行详细研究结果表明：金预铅锌矿床赋存于景星组(K1j)和早第三系云龙组中,并受后期推覆断裂的控制；赋矿层位地层的古环境为极浅水环境(河湖和盐湖环境)；所发现的证据更支持金顶铅锌矿属后生充填型层控矿床的观点。     

论云南兰坪金顶超大型铅锌矿床的成因

在前人大量工作和资料积累的基础上,从成矿构造地质背景、容矿系统、容矿岩石的归属与成因、成矿时代和成矿物质来源方面论述了云南兰坪金顶超大型铅锌矿的成因,指出金顶超大型铅锌矿床是新生代陆陆碰撞造山背景下,在晚始新世至渐新世（大约33Ma）区域挤压推覆转变为区域拉张伸展构造环境转换时期,幔源岩浆和热流驱动盆山转换前被封闭在裂谷或前陆盆地深部富含油气、膏盐和金属的流体,沿着造山带两组伸展构造交汇部位上升,在构造圈闭环境下,通过角砾岩侵位—流砂底辟—流体排泄—金属淀积的产物。     

云南兰坪县金顶铅锌矿床稀土元素特征及意义

通过对金顶矿床稀土元素的分析,显示稀土总量较低,具有轻稀土比较富集、轻重稀土元素具中等分馏的特征。铕(Eu)在铅锌金属矿物和石膏中比较亏损(δEu=0.06~0.76),表现出负异常;而在褐铁矿、天青石中铕(Eu)比较富集(δEu=0.76~14.95),表现出正异常;表明褐铁矿、天青石与其它铅锌矿物不是同一期的产物;暗示金顶铅锌矿床在沉积之后经受了后期热液的改造叠加成矿作用。这对矿床成因研究及勘查具有一定的参考意义。     

西藏拉诺玛铅锌矿与云南金顶铅锌矿对比研究

青藏高原东缘昌都-思茅构造带以其特殊的大地构造位置和业已显现的巨大找矿潜力,日益受到地学界的重视。本文则对同处在该构造带北段昌都盆地内拉诺玛铅锌矿和南段兰坪思茅盆地内金顶超大型铅锌矿作一对比,研究其中共同点和不同之处,并依据区域成矿的理论进行类比,进一步探讨拉诺玛铅锌矿的成矿潜力和找矿方向。     

Fractal Modeling of Sphalerite Banding in Jinding Pb-Zn Deposit, Yunnan, Southwestern China

Sphalerite banding is a common texture in Jinding (金顶) Pb-Zn deposit, Yunnan (云南), southwestern China. The frequency distribution and irregularity of sphalerite grains observed in the bandings are characterized quantitatively by fractal models. Fractal dimensions calculated by several fractal models including box-counting model, perimeter-area (P-A) model, and number-area (N-A) model show the gradual change from outer banding to inner banding, indicating a decrease in area percentage, in irregularity, in shape and in grain size, and an increase in the numbers of grains. These results may imply an inward growth of sphalerite during mineralization, and self-organization properties are involved in the nonlinear process of mineralization.     

Geochemistry and environmental effect of cadmium in the super-large Jinding Pb-Zn deposit,Yunnan Province,China

The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10^-6 to 650×10^-6 with an average of 310×10^-6. In primary ores, Cd concentrations range from 14×10^-6 to 2800×10^-6 with an average of 767×10^-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10^-6 to 8200×10^-6 , averaging 1661×10^-6. It is shown that the oxidized ores are the main carder and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn〉Pb〉Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.     

云南兰坪金顶铅锌矿区土壤中Pb分布特征

采用连续提取法测定兰坪金顶铅锌矿区土壤中Pb的形态含量,通过地统计方法分析污染物的空间分布、化学形态变化特征,结果表明金顶矿区土壤中Pb大范围严重超标,按照国家土壤环境质量标准(Ⅲ级),Pb的中位值超标1.77倍,平均值超标约19倍。插值分布图显示Pb的污染及形态分布受矿体空间展布、地形变化、矿业活动、地表径流等的影响,其中水溶态Pb受植被和水系影响更大。土壤中Pb形态含量依次为残渣态>碳酸盐态>活性铁锰态>有机结合态>离子交换态>水溶态,环境有效态(水溶态、离子交换态与碳酸盐态之和)含量比较高,对兰坪矿区及沘江流域具有潜在的巨大危害     

论兰坪金顶超大型铅锌矿容矿角砾岩的成因

兰坪金顶超大型铅锌矿容矿角砾岩分为两类：一是构造-膏溶角砾岩,不含矿,胶结物孢粉组合显示晚三叠世特征;二是底辟-侵位角砾岩,含铅锌、黄铁矿、天青石和硬石膏矿化,是重要的矿石类型之一,呈脉状产出,系构造-膏溶角砾岩底辟-侵位的产物。它们并非是古新世滑塌堆积成因的角砾岩,不应划归于老第三系云龙组。流行的金顶超大型铅锌矿成矿模式需要重新审定。     

A study on the distribution characteristics and existing states of cadmium in the Jinding Pb-Zn deposit,Yunnan Province,China

The distribution characteristics and existing state of cadmium in the Jinding Pb-Zn deposit were studied. It was discovered that Cd was mainly distributed in sphalerite as an isomorphic impurity. There was a good correla-tion between Cd and Zn in the primary ore. With the oxidation and resolution of pyrite, sphalerite, sulfide, and etc., many secondary minerals, such as colloform sphalerite and smithsonite, were formed. The distribution of Cd is not symmetrical, and enrichment and dilution were observed in partial area of the oxidation zone in the deposit. Cd, except in external pore space or cracks of secondary minerals as independent minerals, such as greenockite, was mainly distributed in sphalerite as an isomorphic impurity in the secondary sphalerate and smithsonite in the oxida-tion zone. The research showed that Cd showed a very strong active transfer ability in the oxidation process, not only indicating that supergene leaching might be the main reason for Cd enrichment in some Pb-Zn deposits, but also reflecting that Cd was easily mobilizeed and transferred to pollute ore areas in the oxidation process. Furthermore, Cd in oxidation ore was more easily mobilized and transferred to induce bad hazards for ore areas with the effect from AMD which was produced from oxidation of sulfides.     

四川荥经县羊儿窝铅锌矿床成矿规律分析

羊儿窝铅锌矿床产于花岗岩与白云岩的不整合面附近破碎带内,矿体呈透镜状、扁豆状、似层状;矿石类型为方铅矿、闪锌矿;铅锌的形成与断裂构造、热液活动、生物活动等有非常密切的关系,矿床成因为热卤水型铅锌矿床。     

峨边老金岩铅锌矿区成矿地质特征及成因

老金岩铅锌矿为四川峨边一马边成矿带上规模较大的矿区之一。通过对该矿区的区域地质背景、成矿地质条件、主要控矿因素进行总结,认为灯影组上部的深灰色不纯白云岩是该区带主要容矿岩石,近南北向的峨边一雷坡断裂和北东向的汉源一峨眉凹陷控制着区内容矿岩石的出露及矿床分布。通过矿床成因的初步探讨,总结了找矿标志,并对找矿前景进行了预测。     

Mantle Source Nature of Ore Fluids for the Jinding Pb-Zn Deposit, Lanping, Yunnan

MANTLE SOURCE NATURE OF ORE FLUIDS FOR THE JINDING Pb-Zn DEPOSIT, LANPING, YUNNANtheNationalClimbingProgram(95 Pre .39;;3 1 2 )andMLMRStrategicKeyProgram (95 0 110 3)