基于磁测资料的六盘山地区构造体系新认识

摘要

六盘山地区位于鄂尔多斯地块西南缘与北祁连造山带的汇聚交接带，多条区域性大型断裂在此交汇复合，对该区的构造体系格架认识存在较多争议，这里通过研究六盘山中南段1∶50000高精度磁测资料，分析磁异常分布特征，结合地质资料判断磁异常原因，并综合化探、电法、重力等资料进行验证，认为研究区由西向东可划分为北祁连碰撞造山带、走廊过渡带、鄂尔多斯西缘逆冲褶皱带三个构造单元，同时鄂尔多斯西缘盆地与北祁连弧盆系的分界线应该为西华山-六盘山东麓断裂带。%Liupan mountain is located at the connecting zone between the southwest edge of Erdos block and north Qilian o-rogenic belt.The place is the intersection of several regional faulting belt.There are lots of arguments about the structural framework.In this paper,we would analysis the distribution of magnetic anomaly based on 1:50 000 high resolution magnetic map,combined with geologic information to derive the cause of magnetic anomaly.Then we would adopt geochemical,electri-cal and gravity to verify the conclusion we got.Finally,we can get that from west to east,the region can be divided into three structural unit:north Qilian mountains collision orogenic belt,Transitional tectonic belt,Erdos west edge thrust fold belt and the boundary of north Qilian mountains collision orogenic belt.The Erdos west edge thrust fold belt should be west Huashan- six Panshan east fracture zone.