The characteristics of time constant of different conductive anomalies from airborne TEM data
LUO Yan1,2, JIANG Min-Zhong1,2, NING Yuan-Li1,2, PENG Li-Hong1,2, ZHU Lin1,2
1. Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang 050002, China;
2. Key Laboratory for Geophysical Exploration Technology Center of Uranium Resource CNNC, Shijiazhuang 050002, China
The principle of airborne time domain electromagnetic system is that Tx coil transmits electromagnetic pulse into ground, and Rx coil receives the induced secondary EM fields from conductive bodies in the earth. The secondary fields generated by induced current of conductive bodies contain geological information. Data processing and interpretation help to achieve prospecting for multi-metal mineral resources. The authors analyzed features of time constant reflection to power line interference under the conditions of near surface conductive bodies, near surface weak conductive bodies, and deep conductive bodies respectively and summarized the characteristics of time constant of different geological bodies based on knowledge of known mineral formation and two years' experience in airborne EM surveys. Some conclusions have been reached: the power line interference generally shows a discontinuous linear anomaly in τ map and electromagnetic response is jumping like irregular attenuation; low resistivity anomaly generally shows high value area in τ map and the electromagnetic response decays exponentially. The low resistance body decays more slowly when the conduction is better and the body is bigger.
骆燕, 江民忠, 宁媛丽, 彭莉红, 朱琳. 不同类型低阻异常航电时间常数的特征分析[J]. 物探与化探, 2016, 40(5): 991-997.
LUO Yan, JIANG Min-Zhong, NING Yuan-Li, PENG Li-Hong, ZHU Lin. The characteristics of time constant of different conductive anomalies from airborne TEM data. Geophysical and Geochemical Exploration, 2016, 40(5): 991-997.
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