Specifications

University of Pretoria etd – Combrinck, M (2006)
Figure 5-10 shows an example of poor correlation between conductivity depth sections
for the two frequencies. In block A conductors are mapped on both frequencies but
with more than 100m discrepancy in depth. In block B a conductor is mapped
consistently over at least 4 stations on the medium frequency, but nothing is seen on the
high frequency although this depth range is well covered. The question is where exactly
these discrepancies originate. Figure 5-11 shows graphs of the measured data on line
450N for both frequencies and Figure 5-12 shows the same for line 1650N. It is clear
that when the measured data correspond well (line 450N) the conductivity depth sections
match. The reason for the discrepancies between dB/dt values for the medium and high
frequencies of line 1650N is not known, but the behaviour of both frequencies is
consistent over four adjacent stations (200m) implying a geological cause and not
acquisition or processing error.
Figure 5-11: Line 450; Stations750 and 1450; medium and high frequency measured data.
113