AUTHOR=Yang Bo , Meng Xiaoling , Wu Yanjun , Yang Longbin , Xu Yixian 

TITLE=Imaging Baogutu granitic intrusions in Western Junggar, NW China using an audio-frequency magnetotelluric array

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 13 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2025.1519524

DOI=10.3389/feart.2025.1519524

ISSN=2296-6463

ABSTRACT=Natural-source audio-frequency magnetotelluric (AMT) data is highly sensitive to conductive anomalies associated with mineralization. To image the three-dimensional mineralized zones in the Baogutu porphyry copper belt, Western Junggar, NW China, we deployed an AMT array consisting of 176 regularly distributed sites. A parallel 3D electromagnetic data inversion scheme was employed to invert this AMT dataset. Using lab-measured electrical resistivity of rock samples, we interpret the 3D resistivity model by comparing it with borehole profiles. The most pronounced conductive anomalies in the inverted model are the east-west elongate conductive zones located at the center of the array, extending to a depth of 600 m. The inverted 3D model aligns closely with the borehole results, demonstrating that the 3D inversion of a dense AMT array can provide a high-resolution and reliable model. The electrical resistivity model shows a strong correlation with the shear wave velocity model. The positive correlation between resistivity and shear wave velocity identifies the potential mineralized areas, as supported by petrophysical and drilling data, which may assist in determining future drilling targets.