摘要
长白山玄武岩覆盖区经历了漫长的地质演化,多期火山喷发,形成了复杂的地质构造,特别是新生代的火山活动形成的大面积的玄武岩覆盖层遮盖了它古老的面貌,为研究区深部地质调查增加了困难。本文结合长白山地区区域地层与构造的分布特征,通过重力异常与区域地质图中岩体的对比,对低重力异常的地质意义进行了分析;同时对玄武岩覆盖区的一条重力和CSAMT剖面数据进行了联合反演与解释,推测研究区的低重力异常主要由中新生代花岗岩所引起;解释结果已经得到了钻探结果的验证。。
The volcanic area of the Changbai Mountain has undergone long-lasting geological tectonics,multiphase volcanic eruptions and thus complicated geological structure shaped.Especially the widespread basalt which was formed because of volcanismin the middle Cenozoic covered its ancient appearance,which makes it more difficult for the deep geological survey in research area.This paper analyzes the geological significance of gravity anomaly by contrasting with the rock in the regional geological map combined with the characteristics of formation and structure in research area.In addition,one geophysical joint profile data of gravity and CSAMT in Changbai mountain basalt cover is processed using joint inversion.We get that the low gravity anomaly is caused by Meso-Cenozoic granite.And it has been verified by drilling results.