Work resumes at Limousine Butte

Vancouver — Prompted by sniffs of gold in the first two rounds of drilling, Newmont Mining (NEM-N) is gearing up for another round at Nevada Pacific Gold’s (NPG-V) Limousine Butte project in Nevada.

In preparation for the upcoming drill season, the major gold producer had increased its land position and started a soil-sampling and ground geophysics program aimed at defining final drill sites. The new drill program will follow up on gold intercepts cut in 999. It will also test newly identified targets.

In 1999, Nevada Pacific inked a deal with Newmont whereby the major could earn up to a 70% interest in Limousine Butte, which is 40 miles southeast of the Carlin trend in eastern Nevada. Newmont can earn a half-interest by spending US$1.5 million on exploration over four years. It can earn another 20% by spending an additional US$1.5 million in years five and six.

The 24-sq.-mile project centres on a large, gold-bearing hydrothermal system which exhibits alteration features similar to sediment-hosted, structurally controlled gold deposits in the Carlin trend and elsewhere in the state. In 1997, when Nevada Pacific staked its first claims in the Limousine Butte area, its geologists recognized the presence of favourable host rocks, significant structural trends and a large, buried copper-gold porphyry system.

The project area is underlain by an Upper Paleozoic sequence of Eastern Assemblage sediments consisting of massive carbonate and calcareous shale, siltstone and sandstone. A large quartz porphyry intrusive stock has extensively altered and mineralized the surrounding sedimentary rocks. The Butte Valley stock is believed to have been emplaced along the Black Metals fault zone, a major structural front. Magnetic surveys indicate the potential for other intrusive bodies along structural trends in the project area.

Nevada Pacific’s exploration team developed a conceptual target model that indicates the potential for three styles of gold mineralization:

• high-grade mineralization occurring under a major low-angle thrust fault, close to the porphyry stock in favourable carbonaceous and calcareous shale units;
• replacement deposits caused by leakage of gold-bearing solutions along favourable unitsupdip and east of the buried intrusive; and
• gold skarn deposits hosted by calcareous shale.

In 1999, Newmont completed an initial 20-hole program of widely spaced reverse-circulation (RC) drilling. It revealed highly anomalous gold intercepts in a large zone of hydrothermal alteration extending over an area measuring 3 miles long and half a mile wide. The program was designed to test prospective target areas that were identified by geological mapping, soil geochemistry and ground geophysical surveys.

Thirteen of the 20 holes encountered highly anomalous gold values. Some of the better intercepts were greater than 20 ft., including:

• Hole 13 — 0.061 oz. gold per ton over 20 ft., beginning at a 370 ft. down-hole, plus 0.016 oz. over 20 ft., starting at 510 ft. down-hole;
• Hole 14 — 0.021 oz. gold over 35 ft., starting at 85 ft. down-hole;
• Hole 16 — 0.019 oz. gold over 30 ft. at 235 ft. down-hole; and
• Hole 18 — 0.026 oz. gold over 50 ft. at 425 ft. down-hole.