• 责任者：K. VEERASWAMY (National Geophysical Research Institute ; Uppal Road ; Hyderabad-500 007 ; India) ; K. K. ABDUL AZEEZ
• 刊名：Chinese Journal of Geophysics
• 出版年：2010
• 卷期：53(3)
• 关键词：地壳 ; crust ; 电性结构 ; electrical structure ; 大地电磁测深 ; telluric electromagnetic sounding ; 喜马拉雅山 ; Himalayas
• 页码：p.576-584
• 图表：10 illus., 1 table, 29 refs.
• 分类号：1600
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

The Himalayas - worlds well known topographic feature in the northern part of Indian plate which is subdivided into several contrasting geological units separated by major tectonic contacts. Lesser and Higher Himalayas form major litho-tectonic units of Himalayan collision belt. The paper presents the electrical conductivity structure from MT investigations carried out in the NS direction across the above major thrust zones (MCT and MBT) lying in between Bilaspur and Rohtangpass situated at elevations of 400 m and 4000 m respectively. The data acquired from 16 MT soundings are analysed and inverted to obtain resistivity models using 2D inversion approach. As the area is characterised with topographic undulations, corresponding elevation values are also included in 2D inversion modelling. 
The results bring out conductivity regions under the Chail and main boundary thrust belts where E-W oriented MCT suddenly takes northward trend. A large resistive block characterizing the Proterozoic basement of the Rampur window in the Lower Himalayas has been delineated in the resistivity model in addition to shallow north dipping conductive and resistive blocks separated by thrust belts. The close proximity of the Rampur window of the Lesser Himalaya on the eastern side of the Chail thrust region and the basement ridges on the western side of the Chail thrust region would have contributed to the northward turn of MBT and associated thrust belts (Kangra reentrant). The stresses for the reentrant could have been due to the basement ridges entering into the Kangra region.