Rio Grande grades confirmed

Vancouver — A newly completed 3,200-metre drill program on the Rio Grandeproperty in northwestern Argentina has returned some encouraging copper-goldvalues for partners Teck (TEK-T) and Mansfield Minerals(MDR-V).

Seven of the 11 holes drilled during the program cut significant swathsof copper-gold porphyry-style mineralization. Highlights include:

• Hole 1 — 50 metres grading 0.29% copper and 0.34 gram gold per tonnefrom 70 metres down-hole;
• Hole 2 — 66 metres grading 0.38% copper and 0.39 gram gold from 6metres down-hole;
• Hole 3 — 66 metres grading 0.36% copper and 0.43 gram gold from 4metres down-hole;
• Hole 4 — 24 metres grading 0.48% copper and 0.54 gram gold from 262metres down-hole;
• Hole 5 — 26 metres grading 0.17% copper and 0.37 gram gold from 112metres down-hole;
• Hole 7 — 27 metres grading 0.35% copper and 0.34 gram gold from 280metres down-hole; and
• Hole 9 — 7 metres grading 0.55% copper and 0.59 gram gold from 240metres down-hole.

Holes 5, 7 and 9 all ended in mineralization.

The 13.5-km property lies 250 km west of Salta. It can be reached by 435km of all-weather road. Mansfield outlined it while conducting a$1.2-million regional exploration program in 1999. The program was funded50% by Teck through a private placement. This entitled Teck to a right offirst refusal on any property acquired under the program that Mansfieldwished to joint-venture.

In December 1999, Mansfield acquired title to the property. It centres ona zone of disseminated and veinlet-controlled chalcopyrite and magnetitemineralization hosted by intense, potassically altered volcanic rocks. TheMain zone has a surface footprint measuring 1.5 km by 1 km. An initial 36grab samples returned values of copper ranging from 0.1% to 3.7% for anaverage of 1.28%, and values of gold ranging from 0.06 to 7.3 grams pertonne for an average of 1.25 grams. The zone extends 100 metres verticallyin exposed topography.

In March, Teck elected to acquire an initial 55% interest in the propertyby spending $4 million over four years and paying a total of $1 million.Teck can earn an additional 10% by financing the property through to thefeasibility stage.