The longitudinal conductivity is one of main parameter in TEM method, but it rarely be used in base metal geophysical prospecting due to many causes.In this paper,a new deduced parameter— is defined and its algorism is proposed. Parameter is a first relative value in TEM.A lot of results of modle caculations and measured data processing are as same direct 1D inversion as apparent resistivity's. But the caculation is so easy and the solution is unique. ΔSτrt could be used in center-near zone for in-loop and coincident loop configuration data processing.
[1] Сидоров В А.脉冲感应电法勘探[M].牛之琏,等 译.中南工业大学电磁法研究组,1991.[2] 朴化荣.瞬变电磁测深曲线视纵向电导解释法//勘查地球物理勘查地球化学文集(第20集电法专辑).北京:地质出版社,1996.[3] 李貅,全红娟,许阿祥,等.瞬变电磁测深的微分电导成像[J].煤田地质与勘探,2003,31(3).[4] 牛之琏.时间域电磁法原理[M].长沙:中南大学出版社,2007.[5] 张杰,吕国印,郭布领,等.高温超导TEM瞬变磁场拟二维反演及应用效果[J].物探与化探,2010,34(2).[6] Buselli G. Interpretation of SIROTEM Data from Elura[M].The Geophysics of the Elura orebody, Cobar, New South Wales.D.W.Emerson, ed.1980.[7] 蒋邦远.实用近区磁源瞬变电磁法勘探[M].北京:地质出版社,1998.[8] 苏朱利,胡文宝.中心回线方式瞬变电磁测深虚拟全区视电阻率和一维反演[J].石油物探,2002,41(2).