山东省胶南市七宝山铅矿区地质矿产特征综合研究

胶南七宝山位于胶东半岛东部地区,区域上属于胶南-威海造山带.山东省地质调查院在此开展普查工作,并通过激电测深、土壤测量、钻孔取芯,以及化学和光谱等分析方法,得出铅矿矿体赋存于断裂构造中,属岩浆热液充填型.矿体主要呈脉状、凸镜状,宽1～3 m,长70～200 m,主要矿体走向近南北,多倾向东.矿石有用化学成分主要为Pb、Ag、CaF2、Cu,Pb含量一般为1.36%～3.96%(平均3.11%),矿体平均厚度3.13m.     

新疆彩霞山铅锌矿床硫、碳、氢、氧同位素地球化学

文章通过对彩霞山铅锌矿床硫、碳、氢、氧同位素的研究,探讨了矿床成矿流体来源及演化,揭示了成矿作用过程中的某些重要信息.初步认为矿石中的硫主要来自同化了海水硫酸盐的岩浆硫,同时有少量生物还原硫参与;碳、氧同位素组成指示碳来源于壳幔混合.成矿流体以建造水为主,早期有岩浆水参与.     

Granite gneiss basement on Flinders Island,South Australia

A U–Pb zircon age of 1762 ± 11 Ma is reported for granite gneiss located on Flinders Island, South Australia. This age is identical, within analytical uncertainty, to a previously reported age for schists of the Price Metasediments located 100 km to the southeast on the southwestern coast of the Eyre Peninsula. The outcrop represents the only known country rock to the Early Mesoproterozoic Calca Granite (Hiltaba Suite) of Flinders Island, the largest island of the Investigator Group of islands, in the southwestern Gawler Craton. The stratigraphic name Investigator Granite Gneiss is proposed for this rock unit. The discovery of the Investigator Granite Gneiss now considerably increases the extent of known Late Palaeoproterozoic rocks on the eastern side of the peninsula. The outcrop was previously included with the considerably younger St Peter Suite granite‐monzogranite, and grouped together with other islands in the Investigator Group. This new dating suggests that the geology on the other islands may require revision. For the first time, detailed major and trace‐element geochemistry is supplied for the granite gneiss on Flinders Island.     

SHRIMP U–Pb geochronology of authigenic xenotime and its potential for dating sedimentary basins

SHRIMP (Sensitive High‐Resolution Ion MicroProbe) analytical procedures have been developed to enable dating of the small, early diagenetic xenotime overgrowths that commonly occur on zircons in siliciclastic sedimentary rocks. The method will be particularly useful in Precambrian terranes, where diagenetic xenotime dating could play a role equivalent to biostratigraphic dating in the Phanerozoic. Reliable ²⁰⁷Pb/²⁰⁶Pb data are more readily obtained than ²⁰⁶Pb/²³⁸U, which also favours application to the Precambrian. However, it is demonstrated that ²⁰⁶Pb/²³⁸U dating of larger overgrowths (>10 μm) is also viable and applicable to Phanerozoic samples. SHRIMP Pb/Pb geochronology of authigenic xenotime in an unmetamorphosed Palaeoproterozoic sandstone in the Kimberley Basin has constrained diagenesis to a precision of ± 7 Ma. In contrast, greenschist‐facies metasediments of the Archaean Witwatersrand Basin, South Africa, contain both authigenic and alteration xenotime that record a complex history of growth from early diagenesis to the last major thermal event to affect the basin.     

An indirect lead isotope age determination of gold mineralization at the Corinthia mine,Yilgarn Block,Western Australia

The Corinthia lode‐gold deposit in amphibolite‐facies greenstone belt rocks in the Southern Cross Province of the Archaean Yilgarn Block contains a largely undeformed pegmatite dyke emplaced during the last phases of movement along the Fraser's‐Corinthia shear zone. Gold mineralization and shear zone development were synchronous, and a Pb‐Pb isochron age of 2620 ±6 Ma for pegmatite emplacement either indirectly dates mineralization, or places a minimum age constraint on the timing of mineralization. This age is in accord with a broadly synchronous dominant episode of Archaean lode‐gold mineralization throughout the Yilgarn Block.     

华南两类不同成因花岗岩的铅同位素组成特征

本文论述了华南两类不同成因花岗岩的铅同位素组成特征。不同类型的花岗岩,具有明显不同的铅同位素组成。改造型花岗岩相对富放射成因铅,其铅同位素比值较高,Pb/~(204)Pb>72;且相对富铀铅而贫钍铅,~(208)Pb/~(206)Pb<2.1。同熔型花岗岩则反之。利用有关的铅同位素图解和参数,可对花岗岩的成因类型进行划分。岩石的铅同位素组成与其成岩物质来源的关系,可从铀(钍)铅同位素的演化得到解释。研究结果表明,花岗岩的铅同位素组成特征,能够提供有关成岩物质来源的信息,从而作为划分花岗岩成因类型的又一个稳定同位素标志。     

meso-四-(4-甲氧苯基)卟啉与铅的显色反应及其双波长和导数光谱行为研究

本文研究了meso-四-(4-甲氧苯基)卟啉与铅的高灵敏显色反应及双波长和导数光谱行为。当有Tween-80存在时,在强碱性介质中,于沸水浴上加热32min,显色反应能定量进行。该体系的表现摩尔吸光系数(ε_(466.5))为1.77×10~5,双波长的ε_(466.5/422)为3.16×10~5,四阶导数光谱的有效摩尔响应值为2.67×10~6。此显色体系用于合成样品中痕量Pb的测定,回收率在96.8～98.2％之间。     

秦岭泥盆系层控铅锌矿床成因模式探讨

在论述秦岭泥盆系层控铅锌矿床的黄铁矿微量元素,硫、铅、氢、氧同位素,矿物气液包裹体均一温度及成分.区域地层元素丰度等方面特征的基础上,提出了该类型属海底含矿热泉溢出沉积和隐伏含矿热泉贯入沉淀的成因模式.     

利用能量传递提高荧光法测铅的灵敏度

基于2-(4′-联苯基)-6-苯基苯并(口恶)唑(PBBO)染料分子发射光谱(λ_(em)~(max)=400nm)和2,3,4,6,7,8-六氢化喹嗪并[9,10,1-f,g]-1-甲基香豆素(CND_(102))的激发光谱(λ_(em)~(max)=388nm)的能级相互匹配,以及表面活性剂胶束的存在是染料分子间能量传递的必备条件,使荧光法测Pb的灵敏度以数量级提高。