【作者】 邓林燕；

【导师】 张展适；

【作者基本信息】 东华理工大学 ， 地球化学， 2012， 硕士

【摘要】 江西相山铀矿田是我国目前已探明储量和正在开采的最重要的铀矿田之一。绿泥石化是沙洲矿床中广泛发育的一种成矿前、成矿期热液蚀变，矿山开采表明以绿泥石化为特征的绿化型矿石不仅是传统硅化型矿石的重要补充类型，而且往往叠加在其它蚀变和矿化类型之上构成富矿类型。论文在分析沙洲矿床区域地质背景、矿床地质特征等基础上，通过野外地质调查和室内显微观察、电子探针分析技术和α径迹蚀刻实验等方法，探讨了矿床范围内绿泥石的分布特征，确定了绿化型铀矿石的矿物共生组合及绿泥石的化学组成，并进一步探讨了绿泥石的化学分类、绿泥石的n(Mg)/n(Fe＋Mg)、nAl/n(Al+Mg+Fe)、AlⅣ、n(Fe)/n(Fe+Mg)等特征值及它们之间的关系，进而计算了绿泥石的形成温度，探讨绿化型矿石的形成环境与形成机制及绿泥石与铀成矿的关系。主要取得以下的认识：(1)沙洲矿床中绿泥石的产状主要有四种类型：一是呈脉状分布的绿泥石，二是由黑云母蚀变而成的绿泥石，三是由长石蚀变而来并与长石紧密共生的绿泥石，四是与沥青铀矿紧密共生的绿泥石；(2)绿泥石的化学组分中镁和铁的含量变化较大；绿泥石主要为鲕绿泥石和蠕绿泥石；绿泥石大部分为泥质岩石来源，仅部分来自于富铁镁的流体，或者在形成过程中受富含铁镁质流体的影响；(3)绿泥石的形成温度变化于169～219℃之间，集中在200～209℃范围，平均温度为200℃，形成于中低温条件下；(4)绿泥石的形成机制主要有两种：一是溶解—沉淀方式，二是溶解—迁移—沉淀方式；(5)α径迹蚀刻实验表明，绿泥石与铀矿化的关系主要体现在两个方面：一是在水-岩作用过程中，黑云母蚀变成绿泥石，使黑云母中以类质同象方式存在的惰性铀释放出来，成为活性铀；二是热液中的活性铀一部分随热液迁移到合适的部位沉淀，还有一部分被新生成的绿泥石等粘土矿物吸附。更多还原

【Abstract】 Xiangshan uranium orefield was one of the most mportant uranium orefield which thereserve was proved and being exploited in china currently.Chloritization was one of themost extensive development hydrothermal alteration in Shazhou deposit before and duringthe uranium mineralization, Mining has proven that Chloritization-uranium-Ore not onlyan important supplement type of the traditional silicon-ore types but also a type ofhigh-grade ore. Papers based on the data of regional geological background, geologicalcharacteristics in Shazhou deposit, field geological investigation, indoor microscopicobservation, electron microprobe analysis techniques and a track etch test method,discussed the distribution characteristics within the scope, and determine the Chemicalcomposition of chlorite. And explore the chemical classification of the chlorite, theeigenvalue of chlorite n (Mg)/n (Fe+Mg), nAl/n (Al+Mg+Fe), AlIV, n (Fe)/n of (Fe+Mg), and the relationship between them to further. And then calculated the formationtemperature of chlorite, explored the formation of green ore environment, formationmechanism and the chlorite relation with uranium mineralization.Obtained the following understanding:(1) There are four Occurrence types of Chloritedistributed in Shazhou deposit: First, a pulse distribution of chlorite; second, Chloritedistributed in the rocks either in pseudomorph of biotite; Third, the Chlorite altered andclose symbiosis with feldspar; Forth, the chlorite symbiosis closely with the Pitchblende.(2)The magnesium and iron changed greatly in chemical composition of chlorite; Chloritemainly Including chamosite and compacted chlorite. Most of the chlorite originatedargillaceous rocks. Only partially come from the fluid which riched in iron andmagnesium.or influence by the fluid which riched in iron and magnesium in the process offormation.(3)The formation temperature varied in169～219℃. Focued in this range of 200~209℃, the average temperature was200℃, which belongs to the low temperatureunder the conditions of the formation;(4)The chlorite formed under reduction condition:Dissolve-precipitation and dissolve-transfer precipitation were the formation mechanism.(5)The track etching experimental results showed Chlorite relationship with uraniummineralization which maily reflected in two aspects: one was in the water-rock interactionprocess, biotite altered to chlorite and make the inert uranium relseased as activity uraniumwith the way of isomorphism. Two was that the activity uranium in the thermal fluidmigrated with the hydrothermal to the proper position of precipitation partly. There was apart of uranium adsorption by the new generatin of chlorite.更多还原