Application of 2D magnetotelluric methods in a geological complex area, Xinjiang, China

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• 作者：Qibin  ; Xiao^a ;   ; ^{s98012@sina.com.cn} ; Xinping  ; Cai^b ; Guanghe  ; Liang^b ; Xingwang  ; Xu^b ; Baolin  ; Zhang^b
• 关键词：Magnetotellurics ; 2D inversions ; Geological complex area ; Xinjiang
• 刊名：Journal of Applied Geophysics
• 出版年：2011
• 出版时间：September 2011
• 年：2011
• 卷：75
• 期：1
• 页码：19-30
• 全文大小：4112 K

文摘

Magnetotelluric (MT) data along two profiles were collected in Tulargen Cu¨CNi mining area, Xinjiang, China. The MT profiles, crossing the known ore-bearing magmatic body, are interpreted to have further understanding of the ore-bearing magmatic bodies' stretch and shape in depth, and to evaluate the prospect in the mining area. The values of phase sensitivity skewness indicate a contaminated two-dimensional (2D) structure (there exist local three-dimensional (3D) structures at shallow level) over 3D structures. G-B decomposition of the impedance tensors indicates the dominant geoelectrical strike in survey area is in East-West direction. To obtain reliable electrical structures, four different 2D inversion codes as REBOCC, NLCG, OCCAM, and ABIC are adopted, inversions of a synthetic 3D model using these codes indicate TM data are more suitable to invert the electrical structures along the profiles in Tulargen Cu¨CNi mining area, while TE and TE + TM inversions can be used to verify the transverse variation of electrical structures at shallow level. The 2D electrical structures show high-resistivity basement covered by relatively low-resistivity strata in the mining area, the conductive anomalies are imbedded in the upper covers. The known ore-bearing magmatic body is coincided with the positions of two conductive anomalies in both profiles at shallow level; its extension at depth is deduced according to the shapes of the anomalies. Other conductive anomalies, isolated and existing only at limited depth as the known ore-bearing magmatic body, are presumed of good prospect.