The Internal Structure of Xiangkashan Ophiolite Revealed by AMT and the Prediction of Deep-buried Chromitites Deposits

Xiangkashan ophiolite is the middle segment of the Luobusa ophiolite. This ophiolite is a part of the eastern portion of the Yarlung Zangbo ophiolite which is controlled by the Indus-Yarlung Zangbo suture zone in Xizang(Tibet), China. Significant progress has been made in recent years towards an understanding of the geological characteristics of this ophiolite. However, understanding the internal structure of the ophiolite remains unclear. The prediction of the deep-buried chromitites deposits proves difficult as well. In the past several years, audio magnetotelluric sounding (AMT) exploration was conducted for prospecting the chromitites deposits in Xiangkashan ophiolite. Some favorite areas proposed by AMT have been verified by drilling, and a large chromitites deposits has been uncovered. Based on the comprehensive study of the AMT, geoelectrical rock physics and drilling result, we propose a model for understanding the internal structure of the ophiolite using geoelectrical and alteration structure. We then predicted a new deep-buried favorite areas of chromitites deposits in northeastern Xiangkashan ore district.