栾川县白土铅多金属矿床稀土元素地球化学特征及其指示意义  

Geochemical Characteristics of Rare Earth Elements in the Dolomite of Longjiayuan Formation and Its Indicative Significance on the Southern Margin of the North China Craton

作　　者：王小涛 梁新辉 张怡静 杨光忠 张争辉 程蓓雷 WANG Xiaotao;LIANG Xinhui;ZHANG Yijing;YANG Guangzhong;ZHANG Zhenghui;CHENG Beilei(Henan first Geology and Mineral Resources Investigation Institute Co.,Ltd.,Luoyang,Henan 471026,China;Key Laboratory of Gold and Silver Polymetallic Ore-forming Series and Deep Prognosis of Henan Province,Luoyang,Henan 471023,China;Key Laboratory of Precious Metal Analysis and Exploration Technology,Ministry of Natural Resources,Luoyang,Henan 471000,China)

机构地区：[1]河南省第一地质矿产调查院有限公司,河南洛阳471026 [2]河南省金银多金属成矿系列与深部预测重点实验室,河南洛阳471023 [3]自然资源部贵金属分析与勘查技术重点实验室,河南洛阳471000

出　　处：《中国锰业》2024年第2期72-78,共7页China Manganese Industry

基　　金：河南省财政地质勘查项目(编号:豫国土资发〔2017〕22)。

摘　　要：华北克拉通南缘官道口群龙家园组白云岩是区域上一套比较特殊的沉积岩地层,其构造演化过程、成岩成矿特征一直是区域地质学研究的热点。通过对区内白云岩及其围岩样品稀土元素测试分析,发现官道口群白云岩ΣREE值明显低于熊耳群安山岩或流纹岩,这与原始沉积期间受到大气淡水的淋漓作用有关,证实该区白云岩属沉积成因;白云岩稀土元素配分模式呈现平坦的页岩标准化曲线形态,说明该区白云岩经历了相似的沉积环境及成岩过程。区内白云岩显示出明显的Eu正异常、Ce负异常,轻稀土富集,反映出还原和弱酸性沉积环境,这可能与华北克拉通南缘元古代以来的构造热事件改造有关,使白云岩稀土元素向轻稀土富集、Eu正异常的方向演化,伴随构造热事件白云岩内铅多金属矿化普遍发育。The dolomite of Longjiayuan Formation in the southern margin of the north China is a special set of sedimentary strata in the region.Its tectonic evolution process,diagenesis and mineralization characteristics have always been the focus of regional geological research.Through the test and analysis of rare earth elements in the dolomite and its surrounding rock samples in the area,theΣREE value of Guandaokou Group dolomite is significantly lower than that of the andesite or rhyolite of Xiong'er Group,which is related to the dripping effect of atmospheric fresh water during the original deposition.It is confirmed that the origin of the dolomite in this area is a sedimentary type.The distribution pattern of rare earth elements in dolomite presents a flat shale standardized curve shape,which indicates that the dolomite in this area has experienced a similar depositional environment and diagenetic process.The dolomite in the area shows obvious positive Eu anomaly,negative Ce anomaly and enrichment of light rare earths,which reflects the reducing and weakly acidic depositional environment.This may be related to the transformation of the tectonic thermal events since the Proterozoic in the southern margin of the north China Craton,which made the dolomite REEs evolve towards the enrichment of light rare earths and positive Eu anomaly,accompanied by the widespread development of lead polymetallic mineralization in the dolomite.

关 键 词：华北克拉通 白云岩 稀土元素 地球化学 指示意义 

分 类 号：P595[天文地球—地球化学] P575[天文地球—地质学]