Airborne electromagnetic characteristics and deep prospecting of a ringed molten rock mass in eastern Tianshan
YANG Bo1,2,3(), SUN Dong-Hua1,2,3
1. Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang 050002, China 2. Hebei Provincial Key Laboratory of Aerial Detection and Remote Sensing Technology, Shijiazhuang 050002, China 3. CNNC Uranium Resources Geophysical Exploration Technology Center (Key Laboratory), Shijiazhuang 050002, China
A ringed molten rock mass in eastern Tianshan, Xinjiang is closely related to Au-Pb-Zn mineralization. Since the mineralization occurs in the fault fracture zone near the outer contact zone between the rock mass and strata, it is necessary to find out the spatial distribution of the rock mass and the development of the fault structure. The processing and analysis of the 1∶25 000 high-resolution airborne transient electromagnetic and aeromagnetic data yielded the following airborne electromagnetic characteristics of the rock mass. The ringed molten rock mass displayed positive and negative alternating ringed aeromagnetic fields. There were four NWW-trending banded zones with strong electromagnetic responses along the ringed molten rock mass, with a time constant of generally 0.07~0.18 ms. Seven NWW-trending faults were inferred and interpreted using the high-value band of the electromagnetic response of the 23rd trace of the dB/dt X component and the aeromagnetic anomaly zone with amplitude of 5~10 nT. By combining the airborne electromagnetic characteristics and three-dimensional inversion results of magnetic vectors, the lithology and structures of the study area were inferred and interpreted again, roughly ascertaining the three-dimensional distribution characteristics of the diorites. Based on these results as well as the known metallogenic geological conditions and the airborne electromagnetic characteristics, two prospecting favorable areas were delineated in the areas with strong electromagnetic responses to the west and southwest of the ringed molten rock mass. This study provides important information on the deep prospecting of the rock mass.
杨波, 孙栋华. 东天山某环状熔融岩体航空电磁场特征及深部找矿研究[J]. 物探与化探, 2022, 46(4): 816-823.
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