川西凹陷雷口坡组稀土元素特征及其意义  

Characteristic and Significance of Rare Earth Elements in Leikoupo Formation,West Sichuan Depression

作　　者：刘伟[1] 徐争启[1] 张成江[1] 尹观[1] 杨治[1] 柳建新[1] 陈翔[1] 

机构地区：[1]成都理工大学地球化学与核资源工程系,四川成都610059

出　　处：《广东微量元素科学》2011年第6期58-64,共7页Trace Elements Science

基　　金：中国地质大调查项目"四川三叠纪富钾卤水富集规律及有利地区调查评价"(编号:1212010011803);成都理工大学金景福基金项目(2011JY0103)资助

摘　　要：对川西凹陷丰卤1井雷口坡组岩屑样品进行了稀土元素(REE)的分析。结果表明,通过REE参数∑REE、LREE、HREE、w(LREE)/w(HREE)、w(LaN)/w(YbN)、δCe和δEu的比较,雷口坡组∑REE与LREE和HREE的变化呈正相关,LREE占∑REE的74%,对∑REE的变化起主要影响作用;REE的含量与样品岩性有关,在硬石膏中相对较小;w(LREE)/w(HREE)与w(LaN)/w(YbN)反映了轻、重稀土间的分异情况,雷口坡组为轻稀土富集型,雷二段至雷四段w(LREE)/w(HREE)与w(LaN)/w(YbN)的比值平均值非常相近,富集与亏损只是发生在体系内部;Ce和Eu的异常主要反映一种氧化还原环境,Ce异常代表的是氧化环境,Eu异常代表的是还原环境。雷口坡组Ce呈弱的负异常,Eu呈强正异且由雷二至雷四段δEu递增,研究认为Eu的强正异常与成岩后期作用有关。The content of REE of Debris samples of leikoupo formation of Fenglu No. 1 well drilling in west Sichuan depression was analysed. The results show that through comparing Z REE, LREE, HREE, w （ LREE ）/w （HREE）, w （ LaN ）/w （ YbN ）, 8 Ce and 8 Eu, the variation is positive correlation between ∑ REE and LREE and HREE of Leikoupo formation, it is main influence that LREE account for 74% of ∑ REE. REE＇ content is related to lithology of rock. , the content is shorter in the anhydrite; The w （LREE）/w （ HREE ） and w （ LaN ）/w （ Ybn ） reflected a differentiation of the earth, it is LREE enrichment type in Leikoupo formation. The specific value equall light and heavy rare y is worth very close from the second to fourth segment in Leikoupo formation, the change hanppened inside the system; The abnormality abnormality of the Ce and Eu mainly reflects a kind environment of the oxidize or revivification, the of Ce represent oxidize environment, the abnormality of Eu represent is to restore environment. The Ce presents a weak negative abnormality, the Eu present strong positive anomaly in Leikoupo formation, and 8 Eu is increased progressively from the second to fourth segment in Leikoupo formation, the study indicates the great abnormality of Eu is related to the late reaction of rock.

关 键 词：稀土元素 REE参数 雷口坡组 卤水 

分 类 号：P595[天文地球—地球化学] O614.33[天文地球—地质学]