甘肃西成矿田铅锌矿床的成矿物质来源探讨

本文系统地研究了甘肃省西成矿田铅锌矿床的地层地球化学和铅同位素地球化学特征,得出了该区成矿金属物质主要取自基底地层而不是含矿层的新认识。     

湘西地区北洛塔和花垣铅锌矿田对比研究

洛塔矿田和花垣矿田是湘西北成矿带铅锌储量较大的两个矿田。文章以洛塔矿田和花垣矿田为研究对象,在前人研究的基础上,从成矿地质构造背景、矿床地质特征、地球化学特征、控矿规律、矿床成因等方面对两大铅锌矿田进行对比研究,发现两矿田在诸多方面存在差异。洛塔矿田铅锌成矿时代为中泥盆世,花垣矿田铅锌成矿时代为早泥盆世,属于上扬子地台东南缘伸展拉张环境下在湘西北地区不同时期不同地段深大断裂活动的产物;构造是两矿田内最重要的控矿要素,岩相、岩性控矿实质上岩石孔隙和裂隙系统控矿,也是构造控矿的一种体现。区内的找矿工作应该沿着控矿构造+有利地层岩性组合的思路进行。     

泗顶铅锌矿田地下水成矿模式

泗顶矿田的铅锌硫化物矿床以碳酸盐岩为主岩,成矿与岩浆活动和变质作用无关。目前一般认为属于沉积改造型层控矿床。然而许多宏观和微观地质事实都说明该矿田的铅锌硫化物矿化是两个不同性质的地下水含水系统的含矿地下水沿印支期断裂破碎带排泄混合成矿的产物。作者认为属于地下水再造矿床。以该矿田的成矿物质来源、成矿作用方式、地层、构造、水文地质、地球化学等综合控矿因素和矿化就位机制为重点,建立了其地下水成矿模式。     

长江中下游铜、金成矿带主要研究进展

长江中下游铜、金成矿带是我国最重要的金属成矿带之一,近年来与成矿带有关的基础地质、矿床地质和成矿规律等研究取得了许多重要的理论成果。本文分析与总结了区域成矿基底特征及地球动力学背景、成矿系列、构造、地层、岩浆岩,以及含矿流体来源、演化及矿床成因的同位素地球化学等方面的主要研究进展。     

香花岭锡多金属矿田微量元素地球化学特征及找矿意义

湖南香花岭矿田是一个Sn多金属矿田,成矿受地层、构造、岩浆岩等多因素复合控制,矿床具有独特的地球化学特征,元素的组合分带表征着不同的矿床类型,同时也反映出矿床的剥蚀深度.     

田湾金矿田韧性剪切带成矿构造地球化学研究

本文主要讨论了田湾金矿田韧性剪切带的成矿构造地球化学特征。田湾矿田各个矿点在空间上均受剪切带的控制 ,表明剪切带是重要的控矿因素。田湾矿田剪切带制约着成矿流体的来源、运移和演化 ,剪切应力、应变作用对成矿元素的活化迁移具有重要的影响 ,为金的成矿提供了物质基础和创造了条件     

新余铁矿田铁矿成矿地质特征与成因分析

新余铁矿田含铁岩系地层物质系统沉积的地球化学环境是一个氧化相-弱氧化相-弱还原相-还原相的演变过程.矿田经历了澄江-加里东构造旋回的多期次、多方向、多型式褶皱构造改造.新余铁矿田矿层和舍铁岩系的各种成矿地质特征以及矿田东、中、西段构造特征是铁矿的沉积成岩作用以及构造演化历史的物质反映.应用系统分析方法和历史分析方法分析矿田成矿地质系统的内在规律,总结新余铁矿田矿层和舍铁岩系变化特征,矿层顶板、底板和含铁岩系标志层特征以及矿田东、中、西段构造特征.解释新余铁矿田单层矿"红绸舞式"褶皱的成因,为铁矿勘查工作提供借鉴.     

香花岭矿田地质特征与地球化学的关系

通过对香花岭矿田地质特征、地球化学资料的综合研究,总结了香花岭矿田地球化学特征及成矿模式,指明了找矿方向.     

广西丹池多金属矿带、大厂锡矿田矿床地球化学特征及找矿标志

本文主要从地球化学的角度,研究矿带,矿田及典型锡矿床的地球化学特征,以摸清成矿规律和总结找矿标志,为今后在矿带内寻找盲矿提供依据。此外还用了化探的几种找矿方法,对锡矿找矿方法的有效性进行了试验。 一、地质概况 丹池多金属矿带位于江南古陆南缘的丹池凹陷带内,走向北西—南东(图1)。出露地层从泥盆系到三迭系,岩性有泥质岩、硅质岩及碳酸盐岩等。锡多金属矿床主要产于泥盆系     

云南个旧松树脚锡矿西部成矿地球化学特征及找矿方向

通过对个旧锡矿松树脚矿田不同成矿部位的岩体和矿床的地球化学特征研究,以已知主要矿体分布地段为对比标准,用七类21项地球化学指标对与主要矿体分布地段毗连的普查区作出了成矿地球化学条件评价,这一评价为近来的工程揭露初步证实,并取得了较好的找矿效果。     

会泽铅锌矿床Pb、Zn成矿物质来源探讨

长期以来,有关会泽铅锌矿床的Pb、Zn成矿物质来源问题存在较大的争论。作者从成矿金属元素地球化学特征、Sr和Pb同位素组成特征出发,全面阐述了会泽铅锌矿床的Pb、Zn成矿物质来源。指出：成矿金属则是来自多方面的,它不仅来源于从震旦系到二叠系碳酸盐岩地层,而且来源于基底岩石（如昆阳群）和峨眉山玄武岩。因此,成矿物质具有多源性。     

New insights into the origin of early Cambrian carbonate-hosted Pb-Zn deposits in South China: A case study of the Maliping Pb-Zn deposit

The western margin of the Yangtze Block hosts the giant Upper Yangtze Pb-Zn metallogenic province, with the occurrence of >400 carbonate-hosted Pb-Zn deposits. More than 50% of these deposits are hosted in carbonate rocks of late Ediacaran to early Cambrian age. Although they have attracted great attention over the past two decades, it is still unclear why such carbonate sequences host so many Pb-Zn deposits and the role that the country rocks played during mineralization. The newly-discovered Maliping Pb-Zn deposit (~6 Mt @ 4.18 wt% Pb and 9.18 wt% Zn) is hosted in early Cambrian strata composed of carbonate and phosphate rocks, black shales, as well as evaporite sulfates, of which the carbonate rocks are the direct ore-hosting rocks. Evidence from mineralogy and the concentrations of ore-forming metals indicate that the phosphate rocks played an important role in providing geochemical barriers during Pb-Zn ore formation. Homogenization temperatures of the primary fluid inclusions in sphalerite and quartz range from 185 to 282 °C, and their salinities vary from 3.39 to 17.17 wt% NaCl equiv. The REE and C-O isotopes imply that the hydrothermal carbonates were formed under relatively oxidizing conditions and that the wall rocks were involved in the Pb-Zn mineralization through dissolution. Sulfur isotopic compositions (δ³⁴S = +7.60–+31.79‰) of sulfides reveal that S²⁻ originated from evaporite sulfates within the ore-hosting strata, and that the black shales acted as an important reducing agent during thermo-chemical reduction (TSR). Pb isotopic ratios of galena (²⁰⁶Pb/²⁰⁴Pb = 17.856–17.973, ²⁰⁷Pb/²⁰⁴Pb = 15.668–15.689 and ²⁰⁸Pb/²⁰⁴Pb = 37.953–38.101) are similar to those of Proterozoic basement rocks in the region. This implies that the basement could be the key source of mineralizing metals. Hence, we propose that: (i) The favorable lithological combination of early Cambrian phosphate rocks, black shales, carbonates and evaporites, as well as Proterozoic basement in the area, were responsible for controlling the majority of Pb-Zn deposits in the late Ediacaran-early Cambrian carbonate sequences in the western Yangtze Block; and (ii) the Maliping Pb-Zn deposit resulted from a combination of mineralized fluids, various trap structures and favorable lithologies, of which the fluids were epigenetic with low to moderate temperatures and salinities.     

地史早期岩石中的铅锌演化--狼山-渣尔泰山中元古代铅锌成矿的物质基础

以中国内蒙古狼山一渣尔泰山中元古代SEDEX型铅．锌成矿带为例，研究了该区从太古代到中元古代地壳岩石的铅锌含量和变化关系以及与成矿的关系。研究发现，从早到晚，岩石SiO2和K2O含量升高，铅含量也与二者同步增加；FeO、MgO、CaO及Na20含量呈下降趋势，锌含量也同步降低。在太古代时，岩石的Zn／Pb比值一般〉8，中元古代时这一比值降低为2～4。矿石的Zn／Pb比值与基底岩石Zn／Pb比值具有很好的一致性。铅锌这种随时间的变化与中元古代铅的暴发性成矿及大规模铅锌共生矿床的形成是同步的，说明基底岩石中的铅和锌是该成矿带SEDEX矿床成矿的物质基础。     

湘西-黔东地区碳酸盐岩容矿铅锌矿床成矿模式

湘西-黔东地区位于扬子陆块东南缘,在该地区碳酸盐岩地层中,目前已发现大、中、小型铅锌矿床及矿点200余处.为了解湘西-黔东地区铅锌矿床成矿作用过程,系统总结了区内主要铅锌矿床地质与地球化学特征,并对成矿机制进行探讨,建立成矿模式.区内铅锌矿床主要赋存于下寒武统碳酸盐岩中,分布明显受断裂及褶皱构造控制,矿体主要为层状、似...     

云南会泽超大型铅锌矿床C、O同位素地球化学

云南会泽超大型铅锌矿床规模大、品位富、伴生有用元素多,预示其成矿环境较为特殊。本文分析该矿床矿石中脉石矿物方解石和赋矿碳酸盐地层的C、O同位素组成,结果表明矿石中脉石矿物方解石的C、O同位素组成相对均一,不同矿体(不同标高)、不同产状以及相同矿体不同产状方解石的C、O同位素组成不具明显差别,其δ13CPDB值和δ18OSMOW值分别为-2.1‰～-3.5‰(均值-2.8‰)和16.7‰～18.6‰(均值17.7‰),在δ13CPDB-δ18OSMOW图上集中于岩浆碳酸岩与海相碳酸盐岩之间的狭小范围内。多方面的证据表明:矿床成矿流体为壳-幔混合流体,其中壳源组分可能主要由矿区(或区域)碳酸盐地层提供,而幔源组分则可能与区域大面积峨眉山玄武岩岩浆活动过程中的去气作用有关。     

贵州普定五指山地区铅锌矿床成矿模式

黔西北五指山铅锌矿集区是川滇黔接壤铅锌成矿域的重要组成部分之一,近年已探明多个大中型铅锌矿床,提交铅锌金属资源储量超250万t,实现了地质找矿的重大突破。文章对区内典型矿床的地质、地球化学等资料进行综合分析,并与邻区及MVT矿床进行比较。研究结果显示,本区矿体主要赋存于上震旦统灯影组和下寒武统清虚洞组白云岩中,呈层状、似层状和陡倾斜脉状产出,断控和层控特征明显。矿石自然类型为原生硫化矿型,主要金属矿物由闪锌矿和方铅矿组成。矿床形成受构造、层位及岩性、沉积岩相等因素的约束,构造是必要条件和主要控矿因素,灯影组和清虚洞组鲕状白云岩是有利赋矿层位和容矿岩性,局限-半局限的台地-泻湖相沉积为有利沉积岩相条件。成矿物质具有混合特征,其中成矿金属Pb、Zn等主要来源于基底岩石,而矿化剂C和S则分别来自赋矿海相碳酸盐岩及其内的蒸发膏岩。成矿流体属于与右江盆地演化有关的低温中低盐度盆地卤水,矿体是富金属流体在早燕山期区域挤压向伸展转换的动力学背景下卸载,与富硫流体混合的产物,成矿过程与MVT矿床相似。五指山地区铅锌矿床成矿模式的建立,有望推动区内找矿新突破,并为邻区铅锌成矿预测提供理论指导。     

麒麟厂铅锌矿银的工艺矿物学研究

笔者应用微区测试研究、粒度统计分析及物相分析等，对云南会泽铅锌矿麒麟厂矿床6号矿体铅锌特富矿石中银的工艺矿物特征进行了研究，认为银以类质同象和独立矿物两种状态存在，发现了11种银矿物和含银矿物，方铅矿是银的主要载体矿物，银的最佳回收指标为93．52％－99．20％。     

S,Pb, and Sr isotope geochemistry and genesis of Pb–Zn mineralization in the Huangshaping polymetallic ore deposit of southern Hunan Province,China

The Huangshaping Pb–Zn–W–Mo polymetallic deposit, located in southern Hunan Province, China, is one of the largest deposits in the region and is unique for its metals combination of Pb–Zn–W–Mo and the occurrence of significant reserves of all these metals. The deposit contains disseminated scheelite and molybdenite within a skarn zone located between Jurassic granitoids and Carboniferous sedimentary carbonate, and sulfide ores located within distal carbonate-hosted stratiform orebodies. The metals and fluids that formed the W–Mo mineralization were derived from granitoids, as indicated by their close spatial and temporal relationships. However, the source of the Pb–Zn mineralization in this deposit remains controversial.Here, we present new sulfur, lead, and strontium isotope data of sulfide minerals (pyrrhotite, sphalerite, galena, and pyrite) from the Pb–Zn mineralization within the deposit, and these data are compared with those of granitoids and sedimentary carbonate in the Huangshaping deposit, thereby providing insights into the genesis of the Pb–Zn mineralization. These data indicate that the sulfide ores from deep levels in the Huangshaping deposit have lower and more consistent δ³⁴S values (− 96 m level: + 4.4‰ to + 6.6‰, n = 13) than sulfides within the shallow part of the deposit (20 m level: + 8.3‰ to + 16.3‰, n = 19). The δ³⁴S values of deep sulfides are compositionally similar to those of magmatic sulfur within southern Hunan Province, whereas the shallower sulfides most likely contain reduced sulfur derived from evaporite sediments. The sulfide ores in the Huangshaping deposit have initial ⁸⁷Sr/⁸⁶Sr ratios (0.707662–0.709846) that lie between the values of granitoids (0.709654–0.718271) and sedimentary carbonate (0.707484–0.708034) in the Huangshaping deposit, but the ratios decreased with time, indicating that the ore-forming fluids were a combination of magmatic and formation-derived fluids, with the influence of the latter increasing over time. The lead isotopic compositions of sulfide ores do not correlate with sulfide type and define a linear trend in a ²⁰⁷Pb/²⁰⁴Pb vs. ²⁰⁶Pb/²⁰⁴Pb diagram that is distinct from the composition of the disseminated pyrite within sedimentary carbonates and granitoids in the Huangshaping deposit, but is similar to the lead isotopic composition of sulfides within coeval skarn Pb–Zn deposits in southern Hunan Province. In addition, the sulfide ores have old signatures with relative high ²⁰⁷Pb/²⁰⁶Pb ratios, suggesting that the underlying Paleoproterozoic basement within southern Hunan Province may be the source of metals within the Huangshaping deposit.The isotope geochemistry of sulfide ores in the Huangshaping deposit shows a remarkable mixed source of sulfur and ore-forming fluids, and the metals were derived from the basement. These features are not found in representative skarn-type Pb–Zn mineralization located elsewhere. The ore-forming elements (S, Pb, and Zn) from the granitoids made an insignificant contribution to sulfide precipitation in this deposit. However, the emplacement of granitoids did provide large amounts of heat and fluids to the hydrothermal system in this area and extracted metals from the basement rocks, indicating that the Jurassic magmatism associated with the Huangshaping deposit was crucial to the Pb–Zn mineralization.     

阿尔泰可可塔勒铅锌矿床围岩蚀变及成因

可可塔勒铅锌矿床受火山喷发中心和沉积洼地控制，铅锌沉淀于海进阶段的局限还原卤水池中；矿下存在大型蚀变带，构成成矿流体对流循环过程中的水-岩作用带；后期造山挤压过程使地层和矿体倒转，矿床最终定位于麦兹倒转向斜之北东倒转翼的东南近转折部位。指出该矿床属海底火山喷流沉积改造型块状硫化物铅锌矿床。