地球化学新方法在隐状矿床找矿预测中的应用研究

With the progress of prospecting, the need for the discovery of blind ore deposits become more and more urgent. To study and find out the method and technology for the discovery of blind and buried ores is now a priority task. New geochemical methods are key technology to discover blind ores. Information of mobile components related to blind ores were extracted using this new methods. These methods were tested and applied based on element' s mobile components migrating and enriched in geophysical-geochemical process. Several kinds of partial extraction techniques have tested based on element' s occurrence in hypergenic zone. Middle-large scale geochemical methods for exploration in forest and swamp have been tested. A serious of methods were tested and applied effetely about evaluation of regional geochemical anomaly, 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system instead of the normal net. 1. Element related with ores can be mobiled to migrate upwards and be absorpted by surface soil. These abnomal components can be concentrated by natural or artificial methods. These trace metalic ions partially exist in dissovlvable ion forms of active state, and partially have been absorbed by Fe-Mn oxide, soil and organic matter in the soil so that a series of reaction such as complex reaction have take place. Employing various partial extraction techniques, metallic ions related with the phase of the blind ores can be extracted, such as the technique of organic complex extraction, Fe-Mn oxide extraction and the extraction technique of metallic ions of various absorption phases. 2.1:200000 regional geochemical evaluation anomaly methods: Advantageous ore-forming areas were selected firstly. Center, concentration, morphological feature, belt of anomaly were choosed then. Geological and geochemical anomalies were combined. And geological and geochemical background information were restrained. Xilekuduke area in Fuyun sheet , Zhaheba area in Qiakuerte sheet, the west-north part in Ertai sheet and Hongshanzui anomaly in Daqiao sheet were selected as target areas, in Alertai, in the north of Xinjiang. in Xilekuduke area, 1:25000 soil geochemical methods sampling based on the net in dendritic water system was carried out. Cu anomaly and copper mineralization were determined in the center area. Au , Cu anomalies and high polarization anomaly were determined in the south part. Prospecting by primary halo and organic complex extraction were used to prognosis blind ore in widely rang outcrop of bedrock. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system were used in transported overburden outside of mining area. Shallow seismic method and primary halo found a new blind orebody in mining area. A mineralization site was fou and outside of Puziwan gold mine, in the north of Shanxi province. Developing middle-large scale geochemical exploration method is a key technique based 1:200000 regional geochemical exploration. Some conditions were tested as Sampling density , distribution sites of sample, grain size of sample and occurrence of element for exploration. 1:50000 exploration method was advanced to sample clast sediment supplement clast sediment in valley. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system was applied to sample residual material in A or C horizon. 1:2000 primary or soil halo methods used to check anomalies and determine mineralization. Daliang gold mineralization in the northern Moerdaoga was found appling these methods. Thermomagnetic method was tested in miniqi copper-polymetallic ore. Process methods such as grain size of sample, heated temperature, magnetic separating technique were tested. A suite of Thermomagnetic geochemical method was formed. This method was applied in Xiangshan Cu~Ni deposit which is cover by clast or Gobi in the eastern Xinjiang. Element's content and contrast of anomaly with Thermomagnetic geochemical method were higher than soil anomaly. Susceptibility after samples were heated could be as a assessment conference for anomaly. In some sectors thermo-magnetic Cu, Ni, Ti anomalious were found outside deposits area. There were strong anomal ies response up ore tested by several kind of partial extraction methods include Thermomagnetic, enzyme leach and other partial extractions in Kalatongke Cu-Ni deposit in hungriness area in the northern of Xinjiang. Element's anomalies of meobile were mainly in Fe-Mn oxide and salt. A Copper mineralization site in Xilekuduke anomaly area had been determined. A blind ore was foung by shallow seismic and geochemical method and a mineralization site was found outside this mining area in Puziwan gold deposit in shanxi province. A Gold mineralization site was found by 1:50000 geochemical exploration in Daliang, Inner Mongolia.

REE characteristics of the Fanshan alunite deposit in Zhejiang Province, China

REE geochemistry data from the Fanshan alunite deposit indicated that its ore-forming materials came chiefly from the country rocks, with δCe〉0 for alunite ores. According to the differences in δEu, the alunite ores were divided into three types： weak negative Eu anomaly, weak positive Eu anomaly and remarkable positive Eu anomaly. The phenomena of Ce-enrichment in the ores indicated that the Fanshan alunite deposit was formed in an oxidizing environment. Variations in fO2 are corresponding to those in δEu： Eu anomaly varies from negative to positive with increasing fO2. And two other important factors may impact the occurrence of Eu anomalies： the contents of alkaline feldspar and the protolith structure in the mineralization period.

A preliminary discussion on the bio-metallogenesis of Tl deposits in the low-temperature minerogenetic province of southwestern China

Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.

湘南瑶岗仙钨矿床成矿流体地球化学

瑶岗仙钨矿区地处南岭中段，位于加里东隆起带与印支-燕山凹陷带的交汇地带。为了更深入地研究瑶岗仙钨矿成矿流体的性质和演化，在前人工作的基础上，本文结合流体包裹体的岩相学特征及其产出的构造特征，对瑶岗仙钨矿流体包裹体进行了显微测温和激光拉曼探针分析，从而确定了瑶岗仙钨矿成矿流体的性质，并进一步探讨了其成矿物质来源及成矿机制。 对瑶岗仙石英脉型钨矿床的石英、萤石和矽卡岩型钨矿床中石榴子石流体包裹体的岩相学特征研究表明，与成矿有关的包裹体主要有三类：富液相、富气相和含子晶多相包裹体。脉型钨矿床中石英的包裹体均一温度范围 180℃～300℃，盐度为 0.88～6.45 wt% NaCl；矽卡岩钨矿床中石榴子石包裹体均一温度范围为 190～300 ℃，盐度为 0.1～8.95 wt% NaCl，成矿溶液的密度为 0.70～1.05 g/cm3，说明形成两种类型矿床的流体均属中温、低密度、低盐度流体；两类矿床形成的压力为 32～38 MPa，成矿深度为 1～2 km，因此该矿床是在浅成、低压条件下形成的。激光拉曼探针测试表明，石榴石包裹体的气相成分以 H2O 为主，石英中包裹体的气相成分及其相对含量为 H2O＞CO2＞CH4＞N2＞H2S。由此说明，从矽卡岩型白钨矿阶段到石英脉型黑钨矿阶段，成矿流体中不断有 CH4、CO2和H2O 等挥发份的加入，此时的流体是一种介于岩浆与热液之间的过渡性流体，具有上部偏液、下部偏浆的特点。 根据前人的研究结果以及矿脉中花岗岩角砾的发现，泥盆系、寒武系岩层在花岗岩浆侵入过程中发生了混合岩化，成为成矿物质来源的基础，而真正的成矿母岩应该是深部的花岗岩体，由此推测“赋矿花岗岩并非成矿源岩”，很可能来自深部母岩浆中熔离出的流体。而 CH4 等还原组分的含量增多，推测也有可能来自相对是还原环境的地幔过渡带或软流圈中。

湘南瑶岗仙钨矿床成矿流体地球化学

瑶岗仙钨矿床位于湘东南后加里东隆起和湘、桂、粤北海西—印支坳陷带的交接部位，是南岭地区最典型的石英脉型钨矿床之一。为了深入研究瑶岗仙钨矿的成矿机制，本文在野外地质工作基础上，选取有代表性的样品，进行了氦、氩同位素以及碳、氧、硫稳定同位素研究，探讨了矿床成矿流体的来源，成岩成矿的关系，并初步讨论了矿床的成因模式。论文主要获得以下认识： （1）对瑶岗仙矿区不同硫化物中流体包裹体的氦、氩同位素系统测定表明，该矿床毒砂流体包裹体中3He/4He比值为0.58~2.60 Ra；黄铁矿和黄铜矿流体包裹体中3He/4He比值分别为0.41~1.26 Ra 和0.37~0.43 Ra，黑钨矿流体包裹体中氦同位素组成相对变化较大，其3He/4He比值为0.05~0.49 Ra，这些He同位素组成均明显高于地壳相应值；毒砂流体包裹体中的40Ar/36Ar变化范围在309.94~454.39；黄铁矿流体包裹体中的40Ar/36Ar变化范围在409.12~1822.31；黄铜矿和黑钨矿流体包裹体中的40Ar/36Ar变化范围分别为673~886和325~903，明显高于饱和大气雨水的40Ar/36Ar值。上述氦、氩同位素组成揭示瑶岗仙钨矿床中的成矿流体具有壳、幔两端元混合的特点。结合区域地质构造演化和成矿年代学的研究成果，本文认为瑶岗仙钨矿床的成矿流体是瑶岗仙花岗岩浆分异出的含有地幔He的岩浆流体与大气成因地下水二端元混合的产物。 （2）层解石和方解石的C、O同位素显示，该矿方解石的13CPDB和18OSMOW的变化范围为-2.2‰~ -7.0‰（均值为-4.8‰）和5.6‰~14.4‰（均值为11.3‰）；层解石的13CPDB和18OSMOW的变化范围为-5.5‰~ -6.3‰（均值为-5.8‰）和12.7‰~14.3‰（均值为13.8‰）；该矿方解石、层解石的C、O同位素组成与赣南西华山钨矿床非常类似。这些C、O同位素指示，该矿的成矿流体主要来自岩浆水，后期有少量大气降水的参与。 （3）对瑶岗仙矿区不同硫化物的硫同位素研究表明，该矿硫化物δ34S值的变化范围很窄，为-2.0‰~1.5‰之间，且具有明显的塔式分布。这些特征暗示，该矿的硫来源单一，主要来自岩浆。 （4）瑶岗仙花岗岩过去被视为典型的S型花岗岩，但本文研究发现该花岗岩普遍含有地幔He。结合区域构造背景的最新研究成果，本文认为，原来被认为“由地壳物质重熔形成的”瑶岗仙S型花岗岩体，实际上也是一种岩石圈伸展背景条件下壳幔相互作用的产物，地幔物质和能量的参与在该花岗岩的形成过程中发挥了重要作用。 （5）瑶岗仙钨矿床与矿区复式花岗岩体具有密切时空关系，而且该矿的主要成矿流体和成矿物质均来自矿区花岗岩，故两者亦应具成因联系。

氟、氯对热液钨、铜成矿的制约-以江西德兴铜矿、大吉山钨矿为例

矿化剂在热液矿床成矿过程中的重要作用一直为人们所关注，矿化剂地球化学行为直接影响成矿元素的富集成矿，不同的矿化剂元素可能对金属成矿具有一定的专属性。本文以著名的江西德兴铜厂超大型斑岩铜矿床和大吉山钨矿床作为研究对象，研究F、Cl与W、Cu成矿的关系。主要的认识如下：（1）F在花岗质岩浆中，可以降低岩浆的粘度、密度、固液相线温度、改变熔体结构，而Cl对熔体结构没有多大的影响。F在流体一花岗质熔体相间，绝大多数配分系数小于1.0，趋向于熔体相中配分，DF随体系中F浓度的升高而增加。Cl在流体一花岗质熔体相间的配分系数均大于1.0，且Dc1 随体系中Cl浓度的升高而增大·Cl强烈地趋向富集于流体相中。（2）Cu在流体一花岗质熔体作用过程中，铜总趋向于流体相中分布（DCu都大于1）。特别是在富Cl流体中Cu浓度较高，说明在富含Cl的热液流体能够从共存的熔体中活化迁移出大量的 Cu，S的加入DCu有降低的趋势。钨趋向于熔体相中富集，其配分系数大多小于1.0。（3）德兴铜厂花岗闪长斑岩属钙碱性系列岩石属I型花岗岩类，具有埃达克岩的特征。岩浆来源于深部，在结晶演化过程中发生了围岩物质的混染，这种高铜含量围岩的混染使成矿物质在岩浆中得到富集，有利于铜的活化、迁移。在铜厂岩体不同的蚀变带中，SiO2、K2O、Cu、Mo等从新鲜斑岩甚至弱蚀变带中带出，而在强蚀变带强烈富集，Cl同样有在强蚀变岩石中富集的趋势；而Na2O、Fe从斑岩体中带出，进入流体相中，流体中大量Fe的存在，有利于铜的沉淀、富集成矿。（4）德兴铜厂斑岩体微量元素和稀土元素地球化学特征表明，该岩体发生了流体一熔体作用，分异出来的流体是一种相对富氯的流体，同时成矿流体的流向是从岩体中心向接触带方向流动。（5）大吉山花岗岩具有高SiO2、A/CNK值，显示过铝质特点。黑云母花岗岩是壳源花岗岩但又受到慢源岩浆或慢源流体的影响。随着花岗岩的演化（从I→II→III）SiO2、K2O＋Na2O逐渐增加，ΣFe、Al2O3、CaO、F含量降低，为成矿提供了大量的矿化剂（F）和沉淀剂（Fe、Ca）。Eu负异常从I至III阶段花岗岩逐渐加强，表明该岩浆经历了高度的分异演化。（6）大吉山花岗岩类稀土元素具有“四重效应”配分的特点以及微量元素对玲Rb、Y/Ho、Zr/Hf以及Nb／Ta发生明显分异，暗示在花岗岩岩浆的演化过程中，经历了充分的流体一熔体作用，同时分异出大量富含F、W等矿化剂元素和成矿元素的热液流体，致使钨矿的形成。大吉山石英脉型钨矿的成矿年龄大约在155 Ma。（7）通过对成矿流体和花岗质岩石黑云母、白云母中卤素相对逸度的研究（log(H2O/fHCl）fluid、log（fHF/fHCl）fluid）发现，铜厂斑岩型铜矿床的成矿体系是相对富氯体系，而大吉山石英脉型钨矿床成矿体系相对富氟，同时氟可能主要迁移W、Sn、Nb、Ta等金属元素。（8）结合斑岩型铜矿床成矿流体特征，铜主要以C1的络合物形式存在和迁移，迁移形式主要是CuCl0、CuCl2等。石英脉型钨矿床中，钨主要以钨酸、钨酸盐及其离解形式存在和迁移，如WO42-、HWO4-、NaHWO4、Naw伍．等；在高度富氟的成矿流体中，钨的氟氧络合物（如WO3F-，WO2F42-等）对钨迁移也具有重要的作用。因此，不同矿化剂类型具有一定的成矿专属性，热液铜矿床主要与Cl、S有 关，而热液钨矿床大多与F有关。