浙江煤山牙形石微区原位REE组成及古环境意义

本文利用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)，对煤山D剖面包含二叠纪-三叠纪界线层的牙形石中色变指数(CAI)较低的部分进行微区原位微量元素分析，并与利用溶解法测定的相应的沉积碳酸盐岩围岩稀土元素(REE)的组成进行了对比，探讨了它们的稀土元素组成对环境变化响应的差异及其可能的原因.结果显示，无论是稀土总量ΣREE，还是Ce异常值，牙形石的微区原位REE信息比围岩更能反映出当时的环境变化.这表明牙形石化石比围岩对环境变化更加敏感，利用牙形石微区LA-ICPMS微量元素分析的方法是可靠的.同时，牙形石的Ce异常值还能对早三叠世的环境有较好的指示意义，为二叠纪与三叠纪之交大绝灭主幕开始到早三叠世环境的剧烈变化和长期缺氧环境提供了新的证据. 

In Situ Rare Earth Elements in Conodont from Meishan Section in Zhejiang Province and Implications for Paleoenvironmental Evolution

Trace elements and rare earth elements (REE) contents of conodonts, distinguished by very low color alteration index (CAI), were measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) from Meishan D section across the Permian-Triassic boundary in Zhejiang Province. Comparative analyses of surrounding rocks geochemistry study, using solutions, a significantly different response to paleo-environmental changes was revealed. Present data indicate both the total REE contents in conodont and the Ce anomalies demonstrate a more sensitive change towards temporal environmental evolution than those in whole rocks. Therefore, conodont elements are more sensitive to ambient variation than the surrounding rocks, and it is reliable for LA-ICPMS in situ analysis of conodonts. Meanwhile, we can reconstruct the Early Triassic environment using the Ce anomaly of conodont, and it provides a new evidence for acute evolutions and long-term anoxia conditions from the Permo-Triassic crisis to the Early Triassic.