201和361铀矿床中绿泥石的特征及其形成环境研究  

CHARACTERISTICS AND FORMATION CONDITIONS OF CHLORITE IN No.201 AND No.361 URANIUM DEPOSITS

作　　者：张展适[1] 华仁民[2] 季峻峰[2] 张彦春 郭国林[1] 尹征平 

机构地区：[1]核资源与环境教育部重点实验室(东华理工学院)地球科学系,江西南昌330013 [2]南京大学地球科学系成矿作用研究国家重点实验室,江苏南京210093 [3]核工业华南地质局二九研究所,广东韶关512026

出　　处：《矿物学报》2007年第2期161-172,共12页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:4064201040472147);国家自然科学基金重点项目(批准号:40132010)

摘　　要：绿泥石化是201和361铀矿床最重要的蚀变类型之一。本文在岩石薄片观察的基础上，采用电子探针分析技术研究了绿泥石的共生组合与形貌特征，测定了87个代表性绿泥石的化学成分，并据此划分了绿泥石的化学类型，计算了绿泥石的形成温度、n（Al）/n（Al＋Mg＋Fe）值等相关指数，讨论了绿泥石的形成机制及其与铀成矿的关系。研究表明：①岩石中绿泥石主要呈脉状、黑云母假象或团块状等产出，具有蠕虫状、叶片状等形貌特征；②绿泥石的Fe/Si图解显示201和361铀矿床中绿泥石主要为铁镁绿泥石和蠕绿泥石，少数属密绿泥石；③根据Battaglia提出的经验方程式计算了201和361铀矿床绿泥石的形成温度变化于179-276℃之间，且主要介于230-260℃之间；④绿泥石主要形成于还原环境，其主要的形成机制是溶解-沉淀和溶解-迁移-沉淀。Chloritization was one of the most important ahemtion types in Nos. 201 and 361 uranium deposits. Microscope and electron probe mieroanalyzer （EPMA） were employed to study the configuration and paragenetie association of chlorite, based on the chemical composition data of chlorite, The chemical types of chlorite were divided, formation temperature and n（Al）/n（ Al ＋ Mg ＋ Fe） value were calculated, and the formation mechanism and relationship with uranium mineralization were discussed, The study revealed that： 1 ） chlorite occurred in vein, agglomerate or had the false pattern of biotite type, or the worm or bladed configuration; 2）Fe/Si diagram revealed most of the chlorite occurred in the ferroamesite and aphrosiderite areas, few in the pycnochlorite area; 3 ） the formation temperature of chlorite varied from 179 - 276 ℃, mainly within the range of 230- 260 ℃ as calculated by the empirical equation presented by Battaglia; 4） chlorite was formed in the reducing condition, the main formation mechanisms were dissolution-precipitation and dissolution-migrationprecipitation.

关 键 词：绿泥石 形成温度 溶解-沉淀 溶解-迁移-沉淀 201铀矿床 361铀矿床 

分 类 号：P594[天文地球—地球化学] P619[天文地球—地质学]