利用长周期MT数据研究沪浙地区深部断裂结构

Long Period Magnetotelluric Data-Based Study on Deep Fault Structure in Shanghai and Zhejiang Area

利用新型GMS-06电磁观测系统对上海奉城—浙江湖州大地电磁探测剖面进行了实际数据采集,获得了较高质量长周期的观测数据,为沪浙地区深部电性和断裂结构研究提供了基础资料.开展了与断裂判断相关的视倾子特征响应的研究,通过模型试验和实测数据处理,从电性资料角度为断裂研究提供了新的信息和依据.通过对沪浙地区实测大地电磁剖面的偏移成像处理和反演,结合已有资料,推断了几条切割地壳的深大断裂的主体位置和性质,在深部电性和断裂结构上获得了新的认识.

A magnetotelluric sounding （MT） profile from Fengcheng of Shanghai to Huzhou of Zhejiang were collected on the basis of the new electromagnetic surveying system GMS-06. These long period MT data contribute to the studies of deep electrical and fault structures. The concept of pseudotipper is proposed and the effects to study the faults by using pseudotipped data are presented through model test and field data application. In accordance with MT migration imaging and inversion results, new recognitions about deep conductivity and faults are obtained. Several deep large faults that cut through the crust are deduced and interpreted.