Case Studies - Mineral Exploration

GEOTEM Survey Results Voisey's Bay, Labrador

A GEOTEM survey has been flown over the Voisey’s Bay Nickel Co. Ltd. Properties in Labrador, Canada. The data presented here has been provided by Stephen J. Balch, Inco Technical Services Ltd. with permission from Inco Ltd. and Voisey’s Bay Nickel Co. Ltd. The survey coverage includes the Eastern Deeps, Ovoid and Western Extension mineralised zones. The survey collected both dB/dt and B-field data with a 30 Hz Waveform Frequency and a 4 ms Pulse Width.

Response: 14+00E Ovoid Zone

The Ovoid (31.7 MMT measured resource) is a flat-lying body composed overall of 70% massive sulphide (shown in red) and is located under 20 metres of overburden (shown in grey). In the geologic section, the yellow and pink represent Troctolite at 10-25% sulphide and 25-50% sulphide respectively. The X and Z component GEOTEM data are both distinctly anomalous.

GEOTEM Response: 14+00E Ovoid Zone

GEOTEM Response: 5+00E Discovery Hill Zone, Western Extension

Discovery Hill Zone (7.3 MMT measured resource) mineralisation dips steeply to the north under only a few metres of overburden cover. A strong characteristic X and Z component anomalous response is indicated on the GEOTEM data. The X component is more sensitive to steeply dipping conductors. In this geological section Troctolite at 50-75% sulfide is purple, with the other colours the same as in the previous section.

GEOTEM Response: 5+00E Discovery Hill Zone, Western Extension

GEOTEM Response: 7+00W Reid Brook Zone, Western Extension

Reid Brook Zone (19.0 MMT indicated resource) mineralisation dips steeply to the south and is covered by 90 metres of overburden. The superior depth of detection of GEOTEM is demonstrated here, with strong and distinct anomalies on both the X and Z components. Because of the steep dip of the mineralised zone the X component is stronger, peaking at 1250 ppm.

GEOTEM Response: 7+00W Reid Brook Zone, Western Extension

GEOTEM Response: Main Zone, Eastern Deeps

Main Zone (47 MMT indicated resource) extends east along strike to a vertical depth of 800 metres. The X component GEOTEM response falls off at a faster rate than the Z component, as the depth to the target increases. Therefore very deep conductors tend to be characterised by a Z component response. GEOTEM results on 18+50E, 21+00E and 23+50E indicate that both dB/dt and B-field Z component GEOTEM response detect the mineralisation to a depth of 320 metres. However at a depth of 400 metres (23+50E) only the B-field measurement detects the mineralisation with the weak dB/dt response being lost in the system noise.