Transient Electromagnetic Test Surveys and Scale Model Studies of the Woodlawn Orebody with MPPO 1 Equipment

Abstract Extensive transient electromagnetic (TEM) surveys were completed at Woodlawn with Russian built, single loop MPPO 1 equipment. Prior to the survey, major modifications to the equipment were required to improve stability. Although the accuracy of measurements at late sample times was limited by electrical noise in the area, a regional survey with 100m and 200m square loops delineated a large TEM anomaly over the Woodlawn orebody at early sample times to 2.3ms. Detailed investigations of this anomaly using loop sizes from 25m to 200m indicated the westerly dip of the orebody and its closeness to the surface. Apparent resistivities calculated from the TEM data gave values of less than 10 ohm m near the centre of the orebody and a background of 100 to 500 ohm m. Analogue modelling of the TEM response of the orebody showed that the effective exploration depth of MPPO 1 equipment at Woodlawn is about 60m. TEM is an efficient exploration tool in the search for buried massive sulphide deposits in a geological environment similar to that at Woodlawn.