Due to severe weather condition we applied non-contact measurements [6] instead of traditional measurements with grounded MN line. Current electrode A was motionless and electrical antenna as MN was moveable. Work frequency was 625 Hz. Only one AMN, half-Schlumberger array was used.

Raw data (fig.11, upper) were processed with Median algorithm and in the middle part of fig.11 you can see result. Lower picture shows the rest or geological noise canceled with processing. 

1D data interpretation gave traces of oil polluted zone in limestone as objects of low resistivity (fig.12)

Fig. 11

Fig. 12.  Oil polluted zones (black) in limestone on 1D VES data interpretation