滇西小龙河锡矿床中绿泥石矿物特征及其指示意义  

Characteristics of chlorite minerals from Xiaolonghe tin deposit in West Yunnan,China and their geological implications

作　　者：张伟[1,2] 张寿庭[1] 曹华文[1] 武俊德[3] 肖常先 陈慧军 唐利[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]四川地勘局区调队,成都610213 [3]云南锡业集团,云南个旧610000 [4]云南省腾冲县金山地矿科技服务有限公司,云南保山679100

出　　处：《成都理工大学学报（自然科学版）》2014年第3期318-328,共11页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中央高校基本科研业务费专项资金资助项目(2652013074);构造成矿成藏国土资源部重点实验室开放基金资助项目(gzck2012006);云锡公司科研基金资助项目

摘　　要：小龙河锡矿床近矿绿泥石化蚀变显著,与锡矿的矿化关系密切。绿泥石的矿相学特征显示小龙河锡矿床绿泥石蚀变可分为明显的强弱两种绿泥石化类型。利用电子探针化学成分分析数据,计算了绿泥石的AlIV、Al VI、Fe2+/(Mg2++Fe2+)和Mg2+/(Mg2++Fe2+)等相关参数,并推算出绿泥石形成时的温度、氧逸度和硫逸度。结果表明:随着蚀变的增强,绿泥石中Mg和Si元素含量减少,Al、Mn和Fe元素含量增加;绿泥石主要为富铁的鲕绿泥石,指示绿泥石形成于还原环境。绿泥石的形成温度在196~229℃之间,平均为213℃,lgfO2在-43.4^-48.0之间,平均为-44.6,lgfS2在-15.9^-18.3之间,平均为-16.6。绿泥石形成机制主要为交代-结晶和迁移-结晶2种。绿泥石为锡矿化晚阶段产物,一定程度上反映了锡矿形成条件的变化。Chloritization is obvious near the Xiaolonghe tin deposit.It is closely related to the tin mineralization.Mineragraphy study shows that the chloritization there can be divided into two types, that is,weak chloritization and strong chloritization.The relative parameters of chlorite such as AlIV , AlVI ,Fe2 ＋/（Mg2 ＋ ＋Fe2 ＋ ）,Mg2 ＋/（Mg2 ＋ ＋Fe2 ＋ ）,forming temperature,oxygen fugacity and sulfur fugacity are calculated based on the electron microprobe data.The results show that the contents of Mg and Si increase and the contents of Al,Mn,Fe decrease with the increase of chloritization degree. The chlorite is mainly composed of chamosite which is rich in Fe,indicating that the chlorite forms in a reduced environment.The formation temperature is 196 ~229℃ （averaging 213℃）.The lgf O 2 is-43.4^-48.0 （averaging -44.6）and the lgf S 2 is -15.9^-18.6 （averaging -16.5）.The main formation mechanisms are metasomatism-crystallization and migration-crystallization.This indicates that the chlorites are the products at the late stage of tin mineralization and reflects the change of the conditions when the tin deposit forms.

关 键 词：绿泥石 温度 氧逸度 硫逸度 小龙河锡矿床 滇西 

分 类 号：P618.44[天文地球—矿床学] P578.962[天文地球—地质学]