晋中冀西太原组中段火山事件层岩矿地化特征及其意义

在岩矿鉴定的基础上，对晋中冀西太原组中段普遍发育的一层火山事件层做了岩石化学、稀土元素和微量元素分析。岩石化学、REE配分模式、REE七组分图解、微量元素蛛网图极好的共性特征及微量元素幂函数定律的应用，证明该火山事件层是同源同期岛弧型钙碱性火山喷发产物，并以该火山事件层作为标志层对晋中冀西太原组地层进行了大区域对比。

The Petro geochemical Characteristics and Stratigraphic Significance of the Volcanic Event Layer in Mid Taiyuan Formation from Middle Region of Shanxi and Western Region of Hebei

Results of research on the petrological, petrochemical, rare elements′and trace elements′character-istics of the volcanic event layers in Mid-Taiyuan Formation from middle region of Shanxi and western region of Hebei are presented. Petro-geochemical features, REE distributions, seven-even-numbered- el-ement curves of REE and ratio spiderg rams of trace elements for these pyroclastic rocks perfectly resem-ble, and according to the application of the theory of power function, these pyroclastic rocks considered here should belong to the isochronal products of the same resource, coming from the calc-alk volcanic eruption in island-arc part. The discovery of the isochronal pyroclastic rocks provide the significant in-formation for the division and correlation of strata. In this paper, we can take these volcanic event layers as a marker bed to make regional strata correlation in this area.