西藏念青唐古拉地区铜铅锌多金属矿床热水沉积岩特征与成矿关系

结合西藏念青唐古拉地区目前已发现的铜铅锌多金属矿床或矿(化)点的岩石学研究,并根据各岩类稀土元素的化学组成特征,进一步判断出硅质岩类、富长石岩类、夕卡岩类、富铁锰质碳酸盐岩类、硫酸盐岩类等各岩类的成岩构造环境,研究表明热水沉积岩与热水沉积成矿作用关系十分密切,认为该地区绝大多数铜铅锌矿床属"热水沉积矿床"范畴,成因上与晚古生代裂谷带发育的热水沉积岩密切相关,是旁多(林周)裂谷带扩张充填阶段最重要的成矿事件.     

八方山大型多金属矿床热水沉积岩相特征与矿化剂组分关系

陕西八方山大型(金)多金属矿床赋存在于中泥盆统吉维特晚期的热水沉积岩相中。富SiO2酸酐型热水同生—交代沉积作用形成热水同生沉积微相(层状硅质岩)、热水同生交代微相(微晶石英岩及硅化灰岩)；富Fe^2 - Mg^2 碳酸盐型热水同生沉积作用形成层状含铜硅质铁白云岩；在同生断裂附近，因热水液压致裂-隐爆作用形达含铜黄铁矿硅质铁白云石角砾岩；富Na^ 铝硅酸盐型／富Fe^2 、Mg^2 碳酸盐型热流体在同生断裂中形成热水充填微相(穿层脉状钠长石碳酸岩)；低温热卤水(富F、Ba、B、As、Sb)形成热卤水同生沉积微相。矿质大规模沉淀的地球化学动力学因素为：在热水沉积成矿盆地中，在单一成分热水体系的温度、压力改变而发生快速化学沉淀；不同成分、性态的热水混合后，强烈的酸—碱作用及Eh-pH剧变等，触发热水体系失稳，引起矿质大规模沉积。[SiO2]和F可能是重要的矿化剂。     

内蒙霍各乞铜多金属矿的地球化学特征及成矿的构造环境

研究表明，霍各乞大型铜多金属矿田的Ｃｕ，Ｚｎ，Ｐｂ，Ｆｅ主要来自海底火山喷溢，部分来自海水对基底岩系的淋滤；Ｓ主要来自海水ＳＯ＾２－４的还原，少部分来自地幔；从微量元素，稀土元素，同位素等方面论证了霍各乞矿田中元古宙为大陆边缘弧后裂谷盆地构造环境。     

霍各乞铜多金属矿床的地质-地球化学特征及矿质来源

霍各乞铜多金属矿床的地质-地球化学特征表明该矿床为有海底喷气参与的同生沉积作用所形成。区域变质及岩浆热变质作用对矿床改造也极为明显,但成矿物质重新活化、迁移、富集基本限于含矿层中。改造的结果使得矿床的硫、铅同位素产生均一化作用。     

内蒙古霍各乞铜多金属矿床的含矿建造及矿床成因分析

内蒙古霍各乞矿床是狼山地区著名的大型铜多金属矿床,含矿建造层序依次为中元古界陆缘裂谷拉斑玄武岩系→矿化热水沉积岩系→陆源碎屑岩系。拉斑玄武岩及基性侵入岩大部分变质为绿泥石片岩,但局部残留基性火山岩和辉长岩类变余结构构造,局部达到斜长角闪岩相,且w(Na2O)>w(K2O)。变余辉长岩的稀土总量较低,且轻、重稀土基本没有分异,黑云绿泥片岩的稀土总量较高,其配分曲线呈轻稀土富集、重稀土亏损型。黑云绿泥片岩中B、F、K、Ti、Zn、Rb、Sn、Nb、Ag、Ba、Pb、U相对富集,Cu、Pb、Zn富集系数高于变余辉长岩,表明绿泥石片岩具有热液蚀变的特征。含矿岩段条带状石英岩、透辉透闪石岩的稀土总量偏低,轻、重稀土有明显分异,并表现为特征的正Eu异常。除矿化富集外,微量元素Be、B、F、Rb、Ag、Ba、Th、U也有明显富集,表现了热水富集成因的特征。矿床矿化受岩性层控制的特征明显,并且在一定的构造部位富集,具有热液叠加改造的特征。硫同位素变化范围大,多表现为正值,硫化物δ34S值的大小排序为黄铁矿>磁黄铁矿>黄铜矿>方铅矿、闪锌矿。矿床成因分析表明霍各乞多金属矿床为热水沉积块状硫化物矿化叠加变质热液改造富集而形成的矿床。     

热水沉积岩比多参数动态演化模拟

运用地层垒积序列的概念和待定线性自回归过程的新方法对岩比参数序列进行模拟，划分与热水沉积有关的海底喷流沉积旋回，并研究各旋回三角岩比相区的演化与热水沉积作用强度演化的定量特征，为进一步对热水沉积盆地古地理环境进行三维动态演化模拟奠定了基础。     

华北地台北缘西段铜多金属矿床的热水沉积成因

早元古代后狼山成矿区和于陆缘拉张拗陷阶段，一直延续至晚元古代末期。狼山群食矿岩系中存在的限层变基性火山岩，热水沉积岩和条纹条带状构造，胶状构造均显示狼山成矿区在１８００－９５０Ｍａ期间处于高地热异常的被动大陆边缘。     

桂西南海相热水沉积锰矿勘查地球化学标志——以龙邦、龙昌锰矿为例

通过对桂西南龙邦锰矿和龙昌锰矿进行水系沉积物、土壤、岩石地球化学测量等成果的研究,分析了锰矿有关元素在水系沉积物、土壤和岩石中的地球化学特征,总结了桂西南龙邦、龙昌海相热水沉积锰矿勘查地球化学标志,提出其指示元素组合为:Mn、Ag、As、Sb、Hg、Co、Ni、Ti、V、Ba、Ce、Zn、Mo。     

东升庙矿床成因和找矿研究

对内蒙古东升庙矿床的矿床地质、地球化学特征的研究显示,该矿床的富硫和富锌2种矿体在矿体形态、矿石的金属矿物组合、结构构造、围岩蚀变特征及稀土元素地球化学特征方面均显示明显的差异.矿床的成矿作用有2期:第一期为热水喷流-沉积作用,形成了富硫矿体;第二期为发生于区域变质和变形作用之后的低温热液改造成矿作用,形成了富锌矿体.该矿床含矿地层从上到下多层富硫矿体-碎屑岩-白云质大理岩的岩石组合及富硫矿体形成以后的热液活动是形成富锌矿体的必要条件.在该矿床及其外围的狼山-渣尔泰成矿带内,众多块状硫化物矿床原生矿体之下、或多金属沉积层之下,有可能找到改造型富铜、锌、铅矿体.     

Genesis of the Zhaokalong Fe-Cu Polymetallic Deposit at Yushu, China:Evidence from Ore Geochemistry and Fluid Inclusions

The ore types of the Zhaokalong Fe-Cu deposit are divided into two categories: sulfide-type and oxide-type. The sulfide-type ore include siderite ore, galena-sphalerite ore and chalcopyrite ore, whereas the oxide-type ore include magnetite ore and hematite ore. The ore textures and structures indicate that the Zhaokalong deposit is of the sedimentary-exhalative mineralization type. Geochemical analyses show that the two ore types have a high As, Sb, Mn, Co and Ni content. The REE patterns reveal an enrichment of the LREE compared to the HREE. Isotopic analysis of siderite ore reveal that the δ13CPDB ranges from 2.01 to 3.34 (‰) whereas the δ18O SMOW ranges from 6.96 to 18.95 (‰). The fluid inclusion microthermometry results indicate that homogenization temperatures of fluid inclusions in quartz range from 131 to 181℃, with salinity values of 1.06 to 8.04 wt% NaCl eq. The mineralizing fluid therefore belongs to the low temperature - low salinity system, with a mineralizing solution of a CO2-Ca2+(Na+, K+)-SO42-(F-, Cl-)-H2O system. The geochemical results and fluid inclusion data provide additional evidence that the Zhaokalong deposit is a sedex-type deposit that experienced two stages of mineralization. The sulfide mineralization probably occurred first, during the sedimentary exhalative process, as exhibited by the abundance of marine materials associated with the sulfide ores, indicating a higher temperature and relatively deoxidized oceanic depositional environment. After the main exhalative stage, hydrothermal activity was superimposed to the sulfide mineralization. The later stage oxide mineralization occurred in a low temperature and relatively oxidized environment, in which magmatic fluid circulation was dominant.     

豫西郁山铝土矿床沉积环境分析

豫西郁山铝土矿床是河南省新发现的一大型隐伏铝土矿,属华北地台G层铝土矿。以系统的中—深部钻探工作为基础,根据含铝岩系的岩性组合、沉积构造和地球化学特征,将郁山矿区内上石炭统一段分为2个相和4个微相。提出郁山铝土矿床含铝岩系形成于滨海泻湖潮坪环境,铝土矿主要赋存于豆鲕状(含砂砾屑)铝土矿微相中,为局限潮下带上部环境;认为郁山矿床含铝岩系经历了3期规模不断增大的突发海侵到缓慢海退的沉积环境演化旋回,并形成矿床的3个铝土矿层,最后一次大规模海侵—海退事件形成了区内最连续的铝土矿层(体)。通过研究,进一步完善了华北地台本溪组铝土矿成矿理论。     

Magnetite-Fluorite Rock:A New Rock Type of Hot Water Sedimentation

The new type hot water sedimentary rock -- magnetite-fluorite rock occurs as quasi-layers in flat parts of contact zones between rock body and strata in Bamianshan of Changshan County, Zhejiang Province, China. The main mineral assemblage is fluorite＋magnetite＋cassiterite. The rock shows typical laminated structure and obvious mosaic texture. Its formation temperature is between 123℃-160℃, averaging at 142℃. The major chemical composition of the rock includes CaF2, SiO2, Al2O3, FeO, and Fe2O3; the high-content microelement association includes W, Sn, Be, Rb, Sr, S, and CI; and the total content of REE is low （∑REE between 35.34×10^-6-38.35×10^-6）, showing LREE enrichment type of distribution pattern. Diagenesis： driven by the tectonic stress, the formation water heated in the deep strata had moved along the fissures or fractures in strata and had extracted components from the strata on the way, and finally stagnated in the flat parts of contact zones between rock body and strata. With drop in temperature, magnetite and fluorite were separated from the hot water and precipitated alternately, forming this hot water sedimentary rock with new type mineralogical composition, typical laminated structure, obvious mosaic texture and sub-horizontal occurrence. The characteristics of the new type mineralogical composition, sedimentary tectonic environment and chemical composition are different from that of the well-known traditional hydrothermai sedimentary rocks.     

Magnetite-Fluorite Rock: A New Rock Type of Hot Water Sedimentation

The new type hot water sedimentary rock - magnetite-fluorite rock occurs as quasi-layers inflat parts of contact zones between rock body and strata in Bamiaushan of Changshan County,Zhejiang Province, China. The main mineral assemblage is fluorite magnetite cassiterite. The rockshows typical laminated structure and obvious mosaic texture. Its formation temperature is between123℃-160℃, averaging at 142℃. The major chemical composition of the rock includes CaF2, SiO2,Al2O3, FeO, and Fe2O3; the high-content microelement association includes W, Sn, Be, Rb, Sr, S, andCl; and the total content of REE is low (∑REE between 35.34x10-6-38.35x10-6), showing LREEenrichment type of distribution pattern. Diagenesis: driven by the tectonic stress, the formation waterheated in the deep strata had moved along the fissures or fractures in strata and had extractedcomponents from the strata on the way, and finally stagnated in the flat parts of contact zones betweenrock body and strata. With drop in temperature, magnetite and fluorite were separated from the hotwater and precipitated alternately, forming this hot water sedimentary rock with new typemineralogical composition, typical laminated structure, obvious mosaic texture and sub-horizontaloccurrence. The characteristics of the new type mineralogical composition, sedimentary tectonicenvironment and chemical composition are different from that of the well-known traditionalhydrothermai sedimentary rocks.     

热水沉积铁白云石微斜长石岩的发现及其找矿意义

铁白云石微斜长石岩作为一种特殊岩石类型,在辽东元古宙裂谷块状硫化物矿床中与成矿关系密切。岩石呈韵律层状,富含Ｋ、Ｂ、Ｓｉ,在Ａｌ２Ｏ３—ＳｉＯ２—（ＣａＯ＋ＭｇＯ）和Ｆｅ—Ｍｎ—（Ｃｕ＋Ｎｉ＋Ｃｏ）三角图上均落入热水沉积岩区。稀土元素具有铈负异常、轻稀土元素富集等特征。硅同位素地球化学显示该岩石为热水沉积成因。此类岩石做为一种热水沉积岩具有重要的找矿意义,依据这一标志在老矿山外围已经找到了硫化物矿体。     

西藏浦桑果铜多金属矿床侵入岩的地球化学特征及对构造环境的约束

浦桑果铜多金属矿床是在南木林火山盆地内新近发现的矽卡岩型铜多金属矿床.文章对矿区内的花岗闪长岩、花岗闪长斑岩和闪长玢岩进行了岩石地球化学研究,结果表明:这些岩石的ω(SiO2)介于59.08％～67.28％,ω(Al2O3)为15.38％～16.86％,ω(MgO)为1.52％～4.06％,ω(TFeO)介于1.2％～3.46％,均属钙碱性系列.稀土元素总量为22.0×10-6～148.56×10-6,LaN/YbN比值为17.98～37.57,为轻稀土元素富集.花岗闪长岩、花岗闪长斑岩和闪长玢岩均相对富集Cs、Rb、Sr等大离子亲石元素(LILE),亏损高场强元素(HFSE)Th、U、Nb等,强负铕异常或弱负铕异常,无铈异常或弱铈异常.岩石学、岩石化学、微量元素研究表明,花岗闪长斑岩和闪长玢岩形成于中生代雅鲁藏布新特提斯洋向北部拉萨地体俯冲的岛弧环境,花岗闪长岩形成于青藏高原碰撞后伸展作用环境.     

青海锡铁山铅锌矿床类型刍议

锡铁山铅锌矿床是我国大型块状硫化物矿床之一。该矿床类型认识长期存在争议,目前已有越来越多学者将其视为SEDEX型矿床。本文在近年来块状硫化物矿床成矿构造背景研究进展归纳整理的基础上,结合柴达木盆地北缘早古生代区域地质研究进展,提出锡铁山矿床的成矿构造环境不是以往认为的陆内裂谷,而是活动大陆边缘弧后/间盆地裂谷。鉴于成矿构造环境变化,锡铁山矿床类型也应作出相应调整,由原来的SEDEX型矿床改为VSHMS型矿床。这样做可以达到三个方面的目的:其一,有利于解决现存的成矿构造背景认识与区域地质认识不一致的矛盾;其二,有利于保障本区目前和未来大规模展开的区域成矿研究及找矿勘查评价建立在正确的成矿背景认识前提之下;其三,将矿床类型划分与成矿构造背景相结合,进而用矿床类型揭示构造背景,体现了矿床研究为地球系统科学服务的宗旨。     

青海索拉沟铜多金属矿床地球化学特征及矿床成因讨论

依据青海索拉沟铜多金属矿床地质地球化学特征,特别是矿床物质来源、矿物、元素分带、成矿热液演化中铜多金属矿床的性状,对该矿床的地质特征、矿床成因及控矿条件进行了研究。研究表明,该索拉沟铜多金属矿床属火山沉积—热液改造型矿床,其矿床经历了沉积成岩和热液改造两个阶段。中三叠世海底火山喷发喷气活动携带大量成矿物质,在浅海台地相对低洼的部位（还原条件下）与火山碎屑物、陆源物一起沉积下来,形成了最初的＂矿源层＂或贫矿层,在随后的（印支期）造山过程中,受强烈构造-岩浆活动的作用,地层中岩石脱水、成矿元素活化、聚集形成富矿溶液,并沿地层层理、岩石破裂运移,交代岩石中化学性活泼的组分或充填于岩石裂隙中富集成矿。