Interpretation of out of loop data in large fixed-loop TEM surveys Les P. Beard, Zonge International, Tucson, Arizona, USA Summary Interpretation of out-of-loop data from fixed-loop transient EM surveys can be enhanced by using plate models. Numerical modeling shows it is possible to distinguish flat- lying conductors from vertical conductive sheets by comparing the appearance of the vertical and along-line out of loop measurements. Where multiple, steeply-dipping conductive sheets exist, the sheet nearest the transmitter may diminish the responses of more distant sheets, but will usually not cause the more distant sheet to be undetectable. Screening increases with closeness of adjacent plates and with increasing conductance. If the screening effect is not taken into

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