红旗岭铜镍硫化物矿床磁性矿物学研究及矿床成因意义

磁黄铁矿是铜镍硫化物矿床含量最多的硫化物之一，常温下只有单斜磁黄铁矿具有亚铁磁性．X射线粉晶衍射和电子探针微区分析显示，红旗岭矿床海绵陨铁状矿石磁黄铁矿以单斜磁黄铁矿（mpo）为主，致密块状矿石磁黄铁矿为单斜磁黄铁矿与六方磁黄铁矿（hpo）混合型．差热与磁热重分析显示致密块状矿石在323℃存在明显的吸热效应，并且这一过程伴随着磁性的转变，表明323℃是矿床中磁黄铁矿的热磁效应与相变点．致密块状磁黄铁矿在400℃恒温30h后淬火条件下使mpo全面转变成hpo，自然冷却则使原矿石中的hpo与mpo全部转变为mpo．这一结果显示了hpo与mpo之间的转变主要取决于样品的冷却速度，暗示铜镍硫化物矿床致密块状矿体的形成可能与高温矿浆的快速冷凝有关．同时，磁铁矿在不同矿体中的含量特点对岩浆铜镍硫化物矿床成因研究也具有启示意义．     

浙江浬渚铁矿床的地质特征及成因探讨

浙江涅渚铁矿床产于上震旦统西峰寺组碳酸盐岩层中。矿床以条带状磁铁矿矿石为主,也产有矽卡岩和浸染矿石及块状矿石。许多研究者认为此矿床是砂卡岩型。今研究表明,矿床的东矿带为岩浆热液一强烈改造型层控矿床,西矿带为岩浆热液一轻微改造型层控矿床。     

河南水洞岭块状硫化物型铜锌矿床特征及成矿模式探讨

水洞岭矿床属秦岭一大别山碰撞带东秦岭构造亚带,该矿床产于早古生界二郎坪群酸性火山岩内,并受水洞岭复向斜东北翼控制。矿体赋存在石英角斑凝灰岩中,呈似层状、透镜状产出,与地层产状一致。通过对矿床地质特征,进一步总结其成矿机制,建立水洞岭块状硫化物型铜锌矿床的成矿模式。     

吉水县芦溪岭钼铜多金属矿床地质特征及找矿方向

吉水县芦溪岭钼铜矿床属斑岩型矿床,矿床(体)受岩体内外接触带控制明显,裂隙带是控矿主要构造,也是矿化体的储矿构造.矿化体大致呈平行多层雁行式排列.矿石类型主要为花岗闪长斑岩型辉钼矿(黄铜矿)矿石、次为千枚岩型辉钼矿(黄铜矿)矿石.通过控矿因素分析,斑岩体内外接触带、断裂破碎带还具备寻找钼、铜、金、钨等矿床的潜力.     

河南省卢氏县班子沟锑矿床地质特征及找矿前景探讨

班子沟锑矿床地处华北地台和扬子地台两大构造单元的过渡地带,北秦岭褶皱带东段,区域构造线呈NNW—SEE.其赋矿围岩为古元古界秦岭群(Pt1Q)雁岭沟组(Pt1y):主要岩性为白云大理岩、黑云斜长片岩、斜长角闪片岩、云母石英片岩等;本区秦岭群地层属Sb高背景区,微量元素分析结果表明,岩石中Sb、Pb、As等金属元素富集,为矿源层(矿源岩).区域上在双槐树—五里川一带Sb、Pb、As为高丰度值密集异常富集区,该区已查明锑矿床十余处.班子沟矿区位于锑异常富集区中部,目前所探明的矿石类型主要为角砾状矿石、浸染状矿石、脉状—网脉状矿石,通过进一步勘查可望发现大型块状等类型矿床,找矿前景广阔.     

吉林老岭大横路式热水沉积叠加改造型钴矿床

大横路式钴矿床位于辽吉元古库裂谷带中部的老岭金、多金属成矿带中,是国内近年来发现和查明的新类型钴矿床。该类矿床产于古元古代老岭群富硼、碳千枚岩夹石英岩（硅质岩）建造之中;矿体由含碳绢云千枚岩、含电气石绢云千枚岩、石英岩、电英岩组成,呈层状、鞍状产出,产状与国岩一致;矿石中钴呈独立矿物硫钴镍矿、辉钴矿、方钴矿和含钴黄铁矿等产出。通过对矿床层控特征、矿体产状与矿石组合、矿石沉积组构、容矿岩石地球化学、热水沉积岩、稀土元素及同位素组成等几方面的研究,证明该矿床具有明显的海底热水沉积成因特征,矿床受后期热液改造叠加强烈。从而提出大横路式钴矿床为海底热水沉积－热液叠加改造型矿床。     

河南桐柏地区刘山岩铜锌块状硫化物矿床地质特征研究

刘山岩块状铜锌硫化物矿床产于寒武系二郎坪群刘山岩岩组的石英角斑岩-硅质岩中。矿体呈脉状和透镜状产出,受刘山岩韧-脆性断裂的控制,产状与地层基本一致,但品位和厚度变化较大。矿石矿物主要为闪锌矿、黄铁矿与黄铜矿,脉石矿物为石英、绢云母、重晶石和绿泥石。矿石具自形-半自形晶结构、它形晶结构、斑状结构,浸染状、块状和条带状构造。矿石结构构造特征和围岩蚀变特征都表明该矿床为火山-喷流型块状硫化物矿床。     

贵州高寨铝土矿床地质特征及成因初探

高寨铝土矿床是黔中-遵义铝土矿带内新发现矿床。矿体主要赋存于下石炭纪九架炉组(C1jj)含铝岩系中上部,呈层状、似层状产出,其厚度变化较小,矿区范围内从南到北矿体连续分布,产状与地层产状基本一致。矿石多呈块状构造,结构特征以沉积作用形成的碎屑结构、鲕粒结构为主。矿石矿物以一水硬铝石为主,脉石矿物多为高岭石、绿泥石等粘土矿物。通过对矿床地质、古地理环境特征等进行详细分析,认为该矿床为风化-沉积型铝土矿。     

块状硫化物矿床地质地球化学特征与形成机理

块状硫化物矿床可分为ＶＭＳ和ＳＥＤＥＸ矿床两大类。文章从赋矿岩石、成矿时代、控矿构造背景、矿石组分、矿化与蚀变等方面总结了两大类矿床的主要地质特征,从成矿流体性质、微量元素、硫同位素和铅同位素等方面总结了两类矿床流体成矿系统主要地球化学特征,论述了块状硫化物矿床的形成机理。     

苏北超高压变质带榴辉岩型金红石矿床及其成因

在苏鲁超高压变质带南部数千个榴辉岩体中，已发现了40个含金红石榴辉岩体，金红石储量达数百万吨。在综述、分析该带榴耀岩的空间分布、岩石矿物学、含矿性等特性的基础上，确定了块状榴辉型和片麻状榴辉岩型两种主要矿石类型。金红石在矿石中主要呈包裹体、粒间充填、蚀变残余和热液充填四种赋存形式，分别代表了四个不同的形成阶段。电子探针分析显示，在高压、超高压变质作用期间，富含Na的深部流体对金红石的成矿可能起了重要的作用。该矿床属典型的榴耀岩型金红石矿床，在成因上与超高压变质作用有关，类似于挪威的Engebφfjellet、俄罗斯的Shubino村和意大利的Pian Paludo矿床，而不同于我国已知的主要金红石矿床。     

Re-Os isotope dating of pyrite from the footwall mineralization zone of the Xinqiao deposit,Tongling, Anhui Province: Geochronological evidence for submarine exhalative sedimentation

The Xinqiao deposit is located in the Tongling area,Anhui Province.This deposit is dominantly composed of stratiform sulfide orebodies,which are restricted to the transitional zone from clastic rocks to carbonates at the base of the Late Carboniferous Huanglong Formation.There are discordant veinlets or networks of mineralization in the footwall rocks below the stratiform sulfide orebodies.The underlying discordant mineralization zones coexist with conformable stratiform sulfide orebodies,which are considered to be the most representative features of massive sulfide deposits formed by submarine exhalative sedimentation.This study reports a pyrite 187Re-187Os isotopic age of 319±13 Ma(MSWD=16) for the footwall mineralization zone.This isochron age is consistent with the interval of strata hosting the conformable stratiform sulfide orebody,and provides direct geochronological evidence for Carboniferous exhalative sedimentary mineralization.     

Origin of ore-forming fluids of the Dachang Sn-polymetallic ore deposit: Evidence from helium isotopes

The ore genesis model for the Dachang Sn- polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro- thermal event or they were products of Devonian syn-sedimentary exhalative-hydrothermal event. This note presents new helium isotope data from fluid inclusions of four pyrites and one fluorite. The pyrites were collected from the stratiform and massive orebodies in the deposit, and their 3He/4He ratios are significantly higher than 1, ranging from 1.7 to 2.5 Ra, which indicates a mantle component in the responsible hydrothermal fluids. It is suggested that the ore-forming fluids were a mixture of deep circulating seawater and a mantle-derived fluid, which are similar to many of those modern submarine hydrothermal fluids. In contrast, the fluorite, collected from a granite-related hydrothermal vein in the deposit, shows a low 3He/4He ratio of 0.7 Ra, which indicates no mantle component involvement in the fluids. Hence, the helium isotope data indicate that the two kinds of fluids from the Dachang deposit may have different origins. Together with other geological and geochemical evidence, it is suggested that the stratiform and massive ore formation has no genetic relation to the Yanshanian granite. Rather, they were likely formed during Devonian submarine exhalative-hydrothermal processes.     

广西隆或金锑矿床稀土、微量元素地球化学特征及其地质意义

隆或金锑矿床是广西右江成矿带新近发现的重要矿床,为了探讨其成矿流体来源,对其地质背景、矿石及围岩的稀土、微量元素地球化学特征进行对比分析研究.结果表明:矿床赋存于下石炭统-上泥盆统一套碳酸盐岩地层中.矿体呈似层状、脉状,主要受近东西向断裂控制.元素地球化学特征指示隆或金锑矿床成矿流体具有壳幔混合特征,但富矿围岩可能不是...     

河南桐柏大河黄铁矿型铜矿床成因特征

本文在讨论大河矿床容矿岩石、矿床地质特征的基础上,探讨了矿床的形成环境和成因。根据容矿岩石一细碧角斑岩的碱度特征。矿床的地质特征、矿石结构和构造、硫和铅同位素组成等特征的讨论,作者认为细碧角斑岩系形成于弧后盆地优地槽环境,矿床成因与下古生代海底火山作用有关,为海底火山热液—沉积矿床。对矿体下伏火山岩中的成矿金属含量与矿床中的成矿金属含量的对比,以及对黄铁矿和重晶石的硫同位素组成两者关系的讨论,推测了成矿物质的来源。最后,与国内外同类矿床对比,大河矿床与我国白银厂、苏联南乌拉尔黄铁矿型铜矿床较为相似。     

浅论泸沽铁矿的火山成因

泸沽铁矿是一个富铁矿床。它的成因,长期存在争论。本文从矿床地质特征、成矿物化环境、物质来源、矿化分布规律诸方面,论证了该矿床属于与海底火山热液有关的气液交代充填型磁铁矿床。矿化物质来源与粗玄岩岩浆喷发有关。矿床位于主火山口与侧火山口之间的过渡地带,矿体受水下火山爆破角砾筒控制。为火山喷发早期流纹岩向粗玄岩过渡阶段的间歇期成矿。文中阐述了成矿温度、压力、pH、Eh及变化规律,并提出了成矿模式和找矿远景地段。     

Filamentous microfossils in a 3,235-million-year-old volcanogenic massive sulphide deposit

The record of Archaean microfossils is sparse. Of the few bona fide fossil assemblages, most are from shallow-water settings, and they are typically associated with laminated, stromatolitic sedimentary rocks. Microfossils from deep-sea hydrothermal systems have not been reported in Precambrian rocks (> 544 million years old), although thermophilic microbes are ubiquitous in modern sea-floor hydrothermal settings, and apparently have the most ancient lineages. Here, I report the discovery of pyritic filaments, the probable fossil remains of thread-like microorganisms, in a 3,235-million-year-old deep-sea volcanogenic massive sulphide deposit from the Pilbara Craton of Australia. From their mode of occurrence, the micro-organisms were probably thermophilic chemotropic prokaryotes, which inhabited sub-sea-floor hydrothermal environments. They represent the first fossil evidence for microbial life in a Precambrian submarine thermal spring system, and extend the known range of submarine hydrothermal biota by more than 2,700 million years. Such environments may have hosted the first living systems on Earth, consistent with proposals for a thermophilic origin of life.     

沂沭断裂带中段及西侧金矿成矿类型及成矿作用

探讨沂沭断裂带中段及其西侧金矿床的成矿类型及成矿作用,为金矿勘查提供依据。研究区金矿床类型包括岩浆期后热液型和绿岩带型,其中岩浆期后热液型又分为矽卡岩型、隐爆角砾岩型和潜火山热液石英脉型。选取铜井金铜矿床和化马湾金矿床作为岩浆期后热液型和绿岩带型金矿类型的典型代表,从矿床的地质特征、矿体特征及成矿作用等方面进行分析。研究表明岩浆作用是岩浆期后热液型矿床成矿主导因素,控矿构造是其空间展布形式;区域变质作用是绿岩带型金矿成矿的主导因素。该地区寻找与燕山期侵入杂岩体有关的火山热液型金矿床是下一步找矿的重要方向,其中次火山侵入杂岩体分布区、爆破角砾岩筒、断裂构造交汇部位以及化探异常与地质标志相对应地段均是找矿勘查的方向。     

广西大厂层控锡石—硫化物多金属矿床的地质特征及形成机制探讨

作者们经过几年来对大厂锡石—硫化物多金属矿床的详细观察和系统研究表明,大厂锡石—硫化物多金属矿床具有明显的层控特征:(1)主要矿体受中上泥盆统地层控制,并呈层状,可以与地层同步挠曲;(2)矿体内保留有典型的沉积成因的结构构造;(3)层状矿中黄铁矿内的Co/Ni比值小于1;(4)矿区及邻区的含矿层位内发现有火山物质存在。主要来自燕山晚期花岗岩的含锡热液受早期沉积(火山沉积)作用所形成的层状硫化物的“地球化学障”作用的控制而沉淀成矿。因此,大厂锑石—硫化物多金属矿床是另一种意义的沉积—(花岗岩)热液迭加改造型矿床。     

广东长坑—富湾金银矿床微量元素及稀土元素地球化学

金银矿体位于同一矿田并共存在同一个构造破碎蚀变带内,严格地受控于下石炭统梓门桥组(C1z)和上三叠统小坪组(T3x)之间的滑覆构造破碎带,这一构造带也是C1z和T3x间的平行不整合界面.围岩蚀变以硅化、粘土化和硫化物化为主.本文通过对金、银矿矿石及围岩的微量元素组成特征的分析,认为金、银矿物质来源是不同的:金可能来源于矿区周围的下石炭统梓门桥组地层,银则来源于粤西地区广泛分布的中-新元古代地层(云开杂岩和震旦系).在对金、银矿体和围岩稀土元素地球化学研究的基础上,推断金、银成矿作用和围岩蚀变作用皆属热液交代作用的结果,而非热水沉积作用的产物.