摘要
CSAMT法被广泛的应用于深部地质找矿,在野外数据采集中常使用较低的工作频率以获得深部地电信息,并且为了提高原始资料的质量,在供电受限的情况下采用小收发距,这些施工方法都会让CSAMT法测量过早地进入到近区。由于近区的电磁场不具有频率测深的条件,在资料处理时需对近区数据进行校正。现阶段近场校正只是在一定程度上起到压制、降低近场效应。虽然无法消除野外采集的近场数据对深部地电信息的影响,但利用校正处理后的近区场资料,仍可以提取与异常相关的地质信息。西梢地热、朱冲铁铜矿等项目的勘查实例表明,在深部存在一定规模低阻体时,其近地表场的低阻效应往往预示着深部存在富水隐伏断裂构造及较大规模的矿体赋存。
The CSAMT has been widely applied on deep part geological prospecting,in field data acquisition usually using lower operating frequency to acquire deep part geoelectric information. To improve primary information quality,under the limited power supply situation,small transmission-receiving distance will be used. All above operations will make CSAMT entering near-field too early.Since the electromagnetic field in near region does not having frequency sounding condition,so that in data processing,near region data should be rectified. At present,the near-field rectification can only suppress,reduce the near-field effect. Although it cannot be eliminated impacts from field acquired near-field data on deep part geoelectric information,but using rectified near-field information,can still extract anomaly related geological information. Exploration case studies of the Xishao geothermal energy,Zhuchong iron-copper ore etc. projects have shown that the deep part low-resistivity body with certain scale,near surface field low resistivity effect usually indicated the existence of deep part moisture-rich concealed faulted structure and large scaled ore body hosted.
引文
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