四川广元上寺剖面二叠系碳酸盐岩稀土元素组成及意义

摘要

为了确定广元上寺二叠系剖面稀土元素的组成及其作为古海洋沉积环境氧化还原指示标识的适宜性，对四川广元上寺二叠系剖面上114个碳酸盐岩样品做了 ICP-MS 分析发现稀土元素在非泥质碳酸盐中整体上呈现亏损，Ce 异常和（La ／Yb）-PAAS 指示的结果差异较大，没有清晰指示二叠系的缺氧事件，稀土元素作为碳酸盐岩沉积环境氧化还原指标时须慎重。但在缺乏有机质和铁锰氧化物作用的情况下，稀土元素仍表现出对沉积环境的良好的敏感性，在几个重要的时期异常表现一致性较好，可以作为非泥炭质碳酸盐岩沉积环境研究的重要参考指标。%To determine REE composition of Guangyuan Permian section in carbonate with the suitability of REE as an indicator of oxidation and reduction of ancient marine in sedimentary environment,the author made an analysis of 114 carbonate rock samples of the section by ICP-MS.Through his testing and analysis,he has found that REE in non argillaceous carbonate is partial negative.The results is differences indicated by Ce anomaly and (La /Yb)-PAAS,which is not a clear indication of anoxic events in Permian.So REE must be carefully selected as the reduction oxidation indicator of sedimentary environment of carbonate.When non argillaceous carbonate is lack of organic substance and Fe /Mn oxide,REE is still shown to be sensitive to sedimentary environment.The consistency of the anomalies in several important periods is good.It can be used as an important reference index for the study of the sedimentary environment of the non argillaceous carbonate rocks.