Partners trench East Bull Lake (January 16, 2002)

Trenching at the East Bull Lake gabbro-anorthosite intrusion near Sudbury, Ont., has turned up more platinum group metals for partners Mustang Minerals (YMU-V) and Falconbridge (FL-T).

Falconbridge is earning a half-interest in more than 90% of the intrusion by providing $5 million for exploration over four years. The major also purchased $1 million worth of Mustang treasury shares as part of the deal.

East Bull Lake is part of the so-called Huronian-Nipissing magmatic belt, a 200-km-long arcuate belt of Proterozoic-aged intrusions, dyke swarms and related volcanics. The belt includes the River Valley pluton, east of Sudbury, though East Bull Lake is the largest of the bunch.

Mustang’s exploration is focused along the margin (or base) of East Bull Lake, where it contacts the surrounding country rock. Exploration to date, including drilling, has confirmed the prospective nature of the contact zone for metal enrichment.

The recent program consists of 17 trenches dug into known showings. In total, 1,036 channel samples were taken.

At the Kid showing, 24 metres averaged 1.05 grams combined platinum, palladium and gold per tonne, including 1.48 grams of the combined metals over 10 metres. Two other channels averaged 2.43 grams over 4 metres, including 3.3 grams over 2 metres, and 1.81 grams over 7 metres, including 2.24 grams over 4 metres.

Here, inclusion-bearing rocks close to the intrusion’s margin host the mineralization. So far, the showing has returned up to 4.98 grams in surface sampling.

The highest grade from the Central showing was 2.33 grams over 7 metres of a 15.7-metre-long channel that averaged 1.92 grams. Two other channels and previous samples yielded similar results.

The Parisien showing averaged 0.84 gram over 21 metres, including 1.36 grams over 6 metres. Higher grades are known here, and the host rocks display a hydrothermal overprint.

Each showing extends for more than 1 km and remains open.

Generally, mineralization at East Bull Lake contains more palladium than platinum, and gold to a much lesser degree. The metals are typically reported together because of their similar metallurgical properties.