Figures 1 and 2 illustrate that the effect of adding a conductive overburden is to mask the response of conductors with a low CTP regardless of whether dB/dt or B-field data is collected. As the CTP is increased the character of the decays is identical to that exhibited when no conductive overburden is present with the same possibility that conductors with a high CTP could be below the instrument noise level for dB/dt systems.