(1. 湖南省地質(zhì)調(diào)查院，長沙410116；
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長沙 410083；
3. 有色資源與地質(zhì)災(zāi)害探查湖南省重點實驗室，長沙 410083)
摘 要: 可控源音頻大地電磁法(CSAMT)中的收發(fā)距和實測波區(qū)的響應(yīng)數(shù)據(jù)息息相關(guān)，決定著該方法的有效勘探深度。長株潭地區(qū)是我國經(jīng)濟高度發(fā)展的重點區(qū)域，區(qū)內(nèi)巖漿巖、褶皺、斷裂發(fā)育；出露巖石有礫巖、砂巖、泥巖、白云巖、灰?guī)r和花崗巖等，具有CSAMT探測地質(zhì)構(gòu)造和巖性接觸帶等地質(zhì)現(xiàn)象的前提條件。但由于區(qū)內(nèi)水系發(fā)育致使大部分巖石電阻率普遍較低，而花崗巖電阻率相對較高，在不同區(qū)域?qū)嵤〤SAMT時，滿足波區(qū)條件的收發(fā)距有所不同。根據(jù)區(qū)內(nèi)不同巖性組成的典型地層結(jié)構(gòu)進(jìn)行數(shù)值計算，計算出最佳收發(fā)距的大小，并選取實例進(jìn)行分析，以期對此地區(qū)或者類似區(qū)域開展CSAMT法探測時有所參考。
關(guān)鍵字: 長株潭地區(qū)；可控源音頻大地電磁法；收發(fā)距；實例分析
（1. Geology Survey Institute of Hunan province, Changsha 410116, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. Key Laboratory of Non-ferrous Resources and Geological Detection, Ministry of Hunan Province, Changsha 410083, China）
Abstract:The response data of CSAMT method is closely related to transmission distance and measured wave region, which determines it’s effective exploration depth. Chang-Zhu-Tan area is the important regional and national area, there exist magmata rocks, folds, fracture and with conglomerate, sandstone, mudstone, dolomite, limestone and granite, which is natural prerequisite to use CSAMT method. However, resistivities of most rock are generally low with water system developmentally, and the resistivity of granite is relatively high, this makes different patches be measured to meet the specifications of receiving valid data from the implementation of CSAMT vary. Depending on the rock area in this article, typical of stratum structure consisting of the numerical calculation, the size of the best receiving distance was calculated, for expecting this area or similar area during some reference when CSAMT method detection was used.
Key words: Chang-Zhu-Tan area; CSAMT method; distance between transmitter and receiver; case study
