Self potential anomaly over a sulphide conductor tested for use as a current source

Abstract

A minus 420 mV self potential anomaly over a sulphide deposit was tested as current source. Two lead electrodes were dug into the ground, one at the place where the negative peak value was found and the other one in a nearby bog. The electrodes were connected through variable load resistances ranging from 1 MΩ to 1 Ω and the voltage drop over the resistances was measured. The current strength through each load resistance which was applied was then calculated. The electrode groundings were then salted with sodium chloride and measurements following the same procedure were repeated after 3 days. The electrodes were then short-circuited for 4 days and the same type of measurements were then carried out. It is concluded that the SP voltage over the two electrodes behaves like an ordinary battery source. A maximum power of 130 μW could be extracted with a voltage drop of 175 mV over a load resistance of 250 Ω.