莫桑比克东部沿海锆钛砂矿矿石质量特征——以赞比西亚省5004C矿区为例

滨海砂矿是目前全球最大的潜在海洋矿产资源之一,仅次于石油与天然气。莫桑比克东部沿海滨海砂矿资源丰富,在世界上占有重要地位。该文结合莫桑比克赞比西亚省5004C矿区锆钛砂矿,分析矿石结构与构造、矿石物质组成、矿物含量及变化等矿石质量特征,为莫桑比克东部沿海锆钛砂矿的勘探和开发提供有利信息。     

滇东南老君山矿集区北部长田W(Sn)矿床成矿时代：来自白钨矿和萤石 Sm- Nd同位素定年的制约

滇东南是我国重要的钨锡多金属成矿区,老君山矿集区是其重要组成部分,围绕燕山期老君山复式花岗岩体,分布有都龙、南秧田、新寨大型-超大型Sn-W多金属矿床及多个中小型矿床(点)。该区地质演化复杂,Sn、W多金属可能存在多期成矿作用,包括燕山期、印支期和加里东期。由于目前该区发现的Sn-W矿化多分布于老君山岩体南、东侧,而岩体北部Sn-W成矿作用的研究相对较薄弱,特别是成矿年代学方面,多数矿床依然缺少精确同位素年代学数据,制约了该区Sn-W多金属成矿作用的认识和地质勘探的深入。长田是老君山岩体北缘代表性W (Sn)多金属矿床,区内加里东期和燕山期花岗岩均有分布,由于缺少年代学数据和地质地球化学研究,W(Sn)成矿作用的认识尚缺少实际地质地球化学依据,难以建立合理的成矿模式,制约了区内地质勘探的深入和突破。基于此,本文通过对长田W (Sn)矿床中白钨矿及共生萤石的Sm-Nd同位素定年,分别获得97 Ma和79 Ma两个年代学数据,显示该矿床钨矿化主成矿期应为燕山晚期,与老君山花岗岩活动时限一致,表明长田钨成矿作用与燕山期老君山花岗岩的侵入活动关系密切,而与加里东期岩浆活动关系不大。该成果丰富了...     

江西德兴铜矿田成矿热液演化过程及其对铼差异性富集的制约

铜厂和富家坞矿床是德兴矿田中两个典型的斑岩铜矿床,二者成矿时代、成矿背景和致矿斑岩均较一致,但前者中辉钼矿的Re含量明显高于后者。为探究成矿流体演化过程对辉钼矿中Re含量差异的影响,本文对铜厂和富家坞不同成矿阶段的石英开展LA- ICP- MS微区原位分析以及流体包裹体测温研究。结果显示,二者流体均具有由高温向低温,中低盐度高盐度共存向低盐度演化的趋势,且温度下降、流体沸腾以及pH值的变化可能是导致Cu、Mo沉淀的主要原因;但就同一成矿阶段而言,铜厂比富家坞成矿温度更低,并且在主成矿阶段,铜厂具有更高的流体盐度;因此,推测温度和盐度可能是导致二者中辉钼矿Re含量差异的主导因素。     

Stable Isotopes and Halogen Geochemistry of the Huayuan Carbonate-hosted Pb-Zn Ore District, South China: Implications for the Salt Source of Ore-forming Fluids

The Huayuan Pb-Zn ore district in China, located in western Hunan Province, is a giant carbonate-hosted Pb-Zn ore district. The source of ore-forming brines in this ore district remains poorly constrained. Whether the highly saline brines are derived from evaporated seawater or dissolved evaporates continues to be intensely debated. Carbonate minerals associated with Pb-Zn mineralization have δ13CV-PDB and δ18OV-SMOW values ranging from ?5.55‰ to +1.35‰ (mean value of ?0.69‰; n = 14) and +16.28‰ to +25.05‰ (mean value of +20.22‰; n = 14), respectively. This indicates that carbonate minerals are dominantly formed from dissolved ore-hosted carbonate rocks. The δ34S values of sulfides range from +20.2‰ to +36.8‰, with an average value of +30.0‰ (n = 27). These results suggest that sulfur is predominantly derived from the thermochemical sulfate reduction of marine sulfate. The crush-leach analyzed solute data of fluid inclusions in sphalerite show the ore-forming fluids have Cl/Br molar ratios range from 118 to 384, and Na/Br molar ratios from 39 to 160 (n = 8). These Cl/Br ratios of hydrothermal fluid are much lower than those of seawater (657 to 564), but are consistent with bittern brines through early halite precipitation. We propose that ore-forming fluids are mainly derived from evaporitic basin brines, which leached base metals from the basement and/or country rocks. The brine then migrated to the basin margins through clastic rocks of basement and then precipitated sul?des by thermochemical sulfate reduction.     

贵州开阳磷矿矿区地质灾害分析

针对矿山深部开采和工程地质灾害的重点危险因素和隐患,指出采用高新技术手段对矿山深部开采和工程地质灾害事故隐患实施监控预警,提高矿山的本质安全程度和保障能力,是矿山控制和消除安全隐患并减轻灾害损失,提高企业市场竞争力的关键。     

地球深部包体与成矿关系——一个有意义的研究方向

结合在实际工作中的体会,提出和讨论了“地球深部包体与成矿关系”这一有意义的研究方向及其先导性科学问题。地球深部包体中镍、金、钼、钨等成矿元素的含量是不均一的,镍和金在地幔岩包体中含量最高,钼在玄武岩及镁铁质麻粒岩包体中最高,而钨在长英质麻粒岩和花岗岩类包体中含量最高。这些反映岩石圈和软流圈以及岩石圈的不同层次中镍、金、钼、钨等成矿元素的含量不均一,分别提供了地壳中镍、金、钼、钨矿床的初始物质来源。这一认识可能给镍、金、钼、钨等金属矿床和矿床集中区的战略预测提供一些新思路。     

阿尔泰大东沟铅锌矿的碳质流体及其成因

大东沟铅锌矿是阿尔泰南缘泥盆纪克朗火山-沉积盆地的块状硫化物矿床之一,在石炭—二叠纪同造山的区域变质过程中,受到热液叠加改造作用,层状铅锌矿体发育脉状石英和矿化。本文对阿勒泰大东沟铅锌矿区石英脉中的包裹体进行了详细的岩相学和显微测温研究,估算出包裹体形成时的物理化学条件,并采用激光拉曼、同步辐射X射线荧光(SRXRF)对流体包裹体进行了成分测试。结果显示,石英脉中的包裹体主要为碳质流体包裹体,多以面状、带状分布,最低捕获温度在209～459℃之间,密度为0.75～1.15g/cm3,最低捕获压力在110～540MPa之间。初步研究表明碳质流体的来源与同造山的变质作用有关,而与海底喷流沉积无关。激光拉曼测试结果表明包裹体气液主要成分为CO2和N2。SRXRF测试碳质包裹体中金属微量元素显示低Cu、Zn、Pb,而富集Au。     

可控源音频大地电磁法深部找矿实验效果

为了考查电磁法在探测深部金属矿及地质构造方面的实际效果,用可控源音频大地电磁法分别在埋深为500 m和1 100 m的两个已知隐伏铁、铜矿体上进行了实验工作。实验结果表明地电异常显示了矿体、断层以及岩层接触带的分布。在矿体埋藏深度小于500 m、矿层较厚时,地电异常十分明显;若矿体埋藏深度大于1 000 m,地电异常主要反应了控矿、容矿构造。     

Metallogenic mechanisms of super-large Cu and Au deposits in the Dexing region and simulating experiments

Based on the results of previous studies and under the direction of the theory of “ore deposit genesis”, the authors made use of high temperature and high pressure experimental facilities and conditions at the Tectono-geochemistry Research Room under the State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, and put the focus on the multi-source of tectonically controlling ore-forming materials, the characteristics of multi-stage and multi-episode hydrothermal activities and mineralization and the characteristics of multi-genesis and multi-ore deposition so as to shed light on the metallogenic mechanisms of super-large Cu and Au deposits. In addition simulating experiments were made on multi-stage and multi-episode tectonic activities and rock and ore deformation, multi-stage and multi-episode tectonic activities and mobilization and migration of ore-forming materials, and multi-stage and multi-episode tectonic activities and superimposition and enrichment of ore-forming materials. The experimental results showed that under the action of multi-stage and multi-episode tectonic stress the deformation and fragmentation of not only rocks and ores have been intensified, and but also the ore-forming materials originally disbursed in the rocks and ores have been mobilized and migrated and superimposed and enriched. The experimental results also provided the scientific experimental data and grounds for deep-going research on the rules of metallogenesis and geneses of super-large ore deposits in the Dexing region, Jiangxi Province.     

四川阿坝地区刷马金矿床地质地球化学特征及成因探讨

通过对刷马地区地质构造、矿床时空演化以及水系沉积物、土壤、岩石地球化学特征的综合研究,结合地质背景和区域地质环境,认为刷马地区金矿床赋存于上三叠统侏倭组变质石英砂岩中,严格受北西向的韧-脆性剪切带控制,与金矿化有关的蚀变主要有黄铁矿化、硅化、碳酸盐化、毒砂化和黄铜矿化,1∶20万、1∶5万水系沉积物和1∶1万土壤均显示有Au、As、Sb、Hg的地球化学组合异常,1∶20万水系沉积物异常显示Au矿矿田范围,1∶5万水系沉积物异常显示矿区位置,而1∶1万土壤异常与矿体展布基本一致,异常带稳定连续、规模大,异常展布受控于韧-脆性剪切带,是有利的Au成矿区,具有巨大的找矿潜力,其矿床类型初步判定为微细浸染型金矿床(卡林型金矿)。