相山火山盆地西北部打鼓顶期火山机构研究

A Study on the Volcanic Edifice of Daguding Age in Northwestern Xiangshan Volcanic Basin

燕山运动中期相山盆地火山活动频繁,按岩浆活动序次可分为打鼓顶期和鹅湖岭期两个旋回。早期旋回形成的打鼓顶组火山岩主要出露于盆地的西北缘,由于受晚期岩浆活动破坏和火山岩的覆盖,打鼓顶期的火山活动特征、火山机构分布至今没有统一的认识。笔者在遥感解译的基础上,通过野外地质调查,对打鼓顶组熔岩的分布与产状以及火山碎屑岩与角砾的分布进行统计,并结合已有的钻孔资料分析,推测打鼓顶期古火山口、火山通道等火山机构的分布,进而分析其喷发模式,初步判定其属于普林尼裂隙式喷发。

There occurred frequent volcano activiation in the middle of Yanshaninan in Xiangshan.The volcano action can be divided into two cycles：Daguding and Ehuling.The Early cycle formed Daguding formation mainly crop out in the northwestern margin of the basin.The feature of this volcano active and distribution of volcanic edifice of Daguding cycle does not come to an unified understanding due to damage of later magma activation coverage of Ehuling formation.Based on the interpretation of remote sensing and analysis of existing drilling data,the distribution of ancient crater and volcanic channels of the volcanic edifice of Daguding cycle and the eruption pattern of volcanic were proposed in the paper by surveying the lava distribution and the occurrence of Daguding formation and performing statistics on the dips of brecciate in the volcanic clastic rocks.The volcano activiation in Daguding cycle was preliminary believed to be fractural erupation of Plinian model.