Geodynamically indicated targeting strategy for shale‐hosted massive sulfide Pb–Zn–Ag mineralisation in the Western Fold Belt,Mt Isa terrane

There is ongoing debate with respect to the genetic models for shale‐hosted massive sulfide Pb–Zn–Ag deposits contained in the Palaeoproterozoic to Mesoproterozoic intracontinental Isa Superbasin in the Western Fold Belt, Mt Isa terrane. Favourable sites of mineralisation can be predicted based on understanding the tectonic setting of the Isa Superbasin, the structural controls of mineralisation and the chemically favourable environments for ore deposition. Shale‐hosted massive sulfide Pb–Zn–Ag deposits are hosted in successions deposited during the dominant sag‐phase of the Isa Superbasin. These deposits are localised at the intersections of major basin‐scale extensional faults and are hosted in both shallow‐marine and deeper water carbonaceous shales that are characteristically anoxic and located near or at maximum flooding surfaces. All major shale‐hosted massive sulfide Pb–Zn–Ag deposits are located to the west of the Mt Isa Rift (ca 1710–1670 Ma). This spatial association is explained by an asymmetrical lithosphere extension model for the evolution of the Isa Superbasin. Elevated geothermal gradients at the location of maximum subcrustal lithospheric thinning to the west of the Mt Isa Rift may have driven the migration of basinal brines. Increased subsidence at this location produced favourable anoxic sedimentary horizons for metal precipitation during orebody formation.     

铅锌富集机制实验研究方法综述

元素富集机制的研究是重现成矿过程和查明成矿机制的基础,有助于深化对矿床的认识,为找矿提供理论依据。本文总结了近年来关于铅锌元素的迁移与沉淀机制的研究及其应用,包括3种铅锌迁移沉淀模式,4种含铅锌流体驱动模式,铅锌的迁移形式及其沉淀机制;同时简述了我国高温高压实验的发展历程以及4种高温高压模拟实验方法。重点介绍了4种高温高压实验模拟方法及其研究现状：(1)高压釜实验;(2)热液金刚石压腔—激光拉曼实验;(3)熔融毛细硅管—激光拉曼实验;(4)计算机模拟实验。从封闭—平衡—静止到(半)开放—非平衡—流动、淬火分析到原位观察,应是今后高温高压实验的发展方向。以地质特征为基础,采用高温高压成岩成矿模拟实验结合计算机模拟,精细刻画成矿过程并揭示元素富集机制不仅是解决实际地质问题的有效手段,更是很长一段时间内要为之努力的方向。     

U-Th-Pb dating of garnet based on LAICP-MS mapping technology: A case study of the Tonglvshan large-scale Cu -Fe-Au skarn depositSCIEI北大核心CSCD

矽卡岩矿床的年代学信息对研究矽卡岩矿床的矿床成因、演变过程、成矿规律和找矿勘查具有重要的指示意义。石榴子石是矽卡岩矿床中的常见矿物,它具有一定的U含量,但是由于其普通铅高以及铀分布不均一的原因,导致激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)点分析获得年龄成功率不高。针对点分析定年遇到的深度分馏和剥蚀点选取、普通铅校正等问题,本文提出一种利用LA-ICP-MS面扫描分析数据的虚拟点构建技术,在Tera-Wasserburg(TW)图中实现普通铅校正来确定含普通铅石榴子石年龄。通过理论推导、数值模拟和实验分析研究发现,利用相关联的^(208)Pb、^(232)Th、^(238)U测量数据校正生成^(208)Pb_(c)/^(238)U指标并据此对TW图中的数据进行数据分组抽样构造虚拟测量点,可以有效地把面扫描测量数据转换为与点分析测量类似但放射母子比例展布更优的数据。利用此方法对长江中下游成矿带鄂东矿区铜绿山大型Cu-Fe-Au矽卡岩矿床石榴子石进行面扫描分析。仅使用15min的样品面扫描数据,在获得了微量元素含量分布的同时,也获得了同位素比值虚拟点,交点年龄为139.2±2.9Ma(MSWD=0.7,n=126),与前人矿床研究结果相一致,验证了此方法的可行性。利用LA-ICP-MS面扫描定年技术不仅可以获得样品元素含量的二维分布图,有利于对样品期次的筛选,剔除包裹体等异常数据;还可以避免点分析中深度分馏和繁复的选点流程及二次分析等步骤,在获得样品元素含量分布的同时获得矿物年龄,为当前矽卡岩型矿床相关的关键金属研究提供了更为便捷的方法。     

辽东玉隆铅锌矿田控矿构造特征与深部赋矿空间分析

辽东玉隆铅锌矿田处于辽吉古裂谷西端中央地带,是区域上重要的铅锌成矿带。区内含矿母岩-大石桥组三段条带状透闪白云石大理岩发育,铅锌矿床成因类型为沉积-变质热液再造矿床,控矿构造为F1次级褶皱、F2褶皱转折端和褶皱翼部剪切滑动角砾岩带。文章提出区内存在类似检德铅锌矿床"如云硐"二期向斜的大褶皱转折端,论述了玉隆至烟囱砬子至响水沟二期向斜一线距地表600～1500m空间存在铅锌矿工业矿体的地质依据。     

贵州省赫章福来厂铅锌矿矿床地质特征及找矿前景分析

福来厂铅锌矿产于江子山背斜NE翼,主要沿NW向构造产出,该矿为黔西北地区铅锌矿集区主要矿床之一,赋矿地层主要为石炭系黄龙组(C_2h),岩性为白云岩、白云质灰岩。本文通过对福来厂矿床地质特征的总结及与相邻矿区典型矿床的类比分析,认为该区找矿前景好,深部找矿潜力大,应该加大找矿力度。     

Lead isotope signatures of Pb-Zn sulfide mineralization in the Reshian-Lamnian area of Azad Jammu and Kashmir,Pakistan

The Reshian-Lamnian area within the Hazara-Kashmir syntaxis in Pakistan is composed mainly of the rocks of the Salkhala, Panjal and Murree formations. Base metal sulfide mineralization in the form of sphalerite and galena with lesser amounts of chalcopyrite and pyrite is present within the Salkhala Formation of the study area. Chemically all these ore phases are homogeneous in composition. The Pb isotopic composition of galena from the area suggests that there is very little or negligible variation in the ratios of ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb. Modal ages ranging from 509 to 562 Ma and the μ values of 10.71 to 10.93 have been calculated for the studied Pb-Zn mineralization. On the basis of field features, mineralogy and Pb-isotope signatures, it is concluded that the Pb-Zn sulfide mineralization in the Reshian-Lamnia area is pre-Himalayan in age and can be correlated with the Cambro-Ordovician (Pan-African) orogenic event.     

内蒙古小西沟铅锌矿床矿石特征及可选性试验研究

小西沟锌铅矿床属于低温热液型矿床,矿石组成复杂,伴生铜和银,研究表明,该矿床矿石中的铅、锌、铜和银主要矿化元素以独立矿物产出,但部分黄铜矿与闪锌矿呈固溶体交生。根据矿石性质确定,该矿床矿石可采用混合浮选铜铅(铜、铅分离)—再浮选锌的工艺流程,通过试验获得符合标准的铜精矿、铅精矿和锌精矿,所用药剂没有环境污染,符合当前技术条件,可以开发利用。     

麦兹矿田铅锌矿化演化特征及找矿

麦兹铅锌矿受下泥盆统化学沉积层及细碎屑沉积层控制，与火山活动，火山活动中心关系密切，属火山喷气沉积改造型铅锌矿床，矿田内具有铅锌矿找矿前景。     

脆硫锑铅矿单矿物分析方法

采用加入与试样相当的锑量进行EDTA标准溶液的标定，并以此计算EDTA对铅滴定度的方法，消除了试样中大量锑的干扰，解决了铅结果系统偏低的问题，并拟定了脆硫锑铅矿单矿物分析流程。