赣南黄泥湖铀矿床绿泥石特征及其铀成矿环境指示意义

Characteristics of chlorites from Huangnihu uranium deposit and their implications in uranium metallogenic environment in the southern part of Jiangxi Province

黄泥湖铀矿床的绿泥石与铀矿化关系密切。在岩矿鉴定的基础上，利用电子探针对绿泥石进行了微区化学成分研究。研究结果表明，该矿床绿泥石主要为富铁种属的铁镁绿泥石和鲕绿泥石，化学成分主要受泥质和铁镁质原岩控制；绿泥石的离子反应以AlIV置换Si、Fe置换Mg为主，以AlVI置换Fe为辅；与铀矿密切伴生的鲕状绿泥石、黑云母假象绿泥石温度为216．23~256．73℃（均值228．6℃）。鲕状、黑云母假象绿泥石与铀矿密切伴生，其成分特征及形成环境指示：黄泥湖铀矿床为中低温热液铀矿床，形成于还原环境，流体富含Al、Fe。

Chlorite is genetically related to uranium mineralization in Huangnihu uranium deposit. By means of microscopic and electronic microprobe analysis, the authors investigated chemical composition and texture of the chlorite and found that chlorite in Huangnihu deposit has the following characteristics： （1） they are mainly Fe-rich chlorite composed of chamosite and brunsvigite, of which chemical composition is mainly affected by mud and marie rock; （2） the Fe-Mg and A1 r4-Si substitution dominates the octahedral substitution supplemented by Al-Fe substitution; the oolitic chlorite and biotite feinted chlorite closely associated with uranium were formed at temperatures of216.23 ~256.73 ℃ （average 228.6℃）. The chemical composition and forming environment of the oolitic chlorite and biotite illusion chlorite suggests that Huangnihu uranium deposit is a low-moderate temperature hydrothermal uranium deposit formed in a reducing environment and iron-rich formation, the ore-forming fluid mainly originated from shale rock, partly from uhramafie or mafic liquid.