Antares, Mansfield hit best Rio Grande intercept yet (September 24, 2007)

Vancouver — Rio Grande project partners Antares Minerals (ANM-V, ANMFF-O) and Mansfield Minerals (MDR-V, MFMNF-O) got a recent market boost, following the release of some of the best drill results to date from their northwestern Argentinean copper-gold property.

Hole RGA-07-034, collared as a 150-metre northerly step-out on the Sofia North zone, cut 189 metres (from 140 metres down-hole) grading 0.7% copper and 0.67 gram gold per tonne, the best intersection so far from the project, and included higher-grade intervals of up to 12 metres at 2.2% copper and 1.85 grams gold.

Higher-grade sections of the hole occur in a breccia-textured feeder structure.

In a release, Mansfield president and CEO Gordon Leask said exploration has outlined strike and dip extensions with feeder-zone grades.

“As our geologic understanding of the deposit has increased, so has the drill success,” he said. “For good projects, it has been said: ‘The more you work them, the better they get.’ This is certainly the case for Rio Grande.”

Mineralization in hole RGA-07-034 was encountered at a shallower depth than expected and remains open to the north and west. The hole is located just northwest of the two previous best holes on the project — RGA-06-026, which cut 158 metres of 0.46% copper and 0.51 gram gold, and RGA-06-024, which returned 128 metres of 0.447% copper and 0.71 gram gold.

Part of a 15,000-metre drill program, results are in for eight holes totalling about 3,600 metres that were positioned to test for extensions of mineralization at depth and along strike. With 21 holes completed as of Sept. 14, assays are pending for 13 holes, while three rigs continue to work the property.

Work by the companies now shows the Discovery and Sofia zones to be continuous, forming a large zone of copper-gold mineralization on the eastern portion of the ring structure.

Antares president and CEO John Black says upcoming drilling will be focused on the previously untested North zone, located northwest of the Sofia zone.

Antares is the operator at Rio Grande and is earning a 50% joint-venture interest by spending US$3.4 million and issuing 300,000 shares to Mansfield by the end of this month. Earlier this year, Mansfield completed a $5.25-million financing in Antares, giving it a 9.8% stake in its partner.

Meanwhile, the latest batch of drill results from Mansfield’s wholly owned Lindero, located about 12 km southeast of Rio Grande, is boosting the growth potential at its porphyry gold project.

Several holes have returned significant gold intercepts that extend and expand zones of mineralization in the deposit.

Hole LDH-81 cut 148 metres (from 36 metres down-hole depth) grading 0.85 gram gold per tonne, extending mineralization into an area previously thought to be a barren, post-mineral intrusive. The interval included a 90-metre section of 1.03 grams gold per tonne.

On the Eastern body of the deposit, hole 84 returned 140 metres (from 34 metres) of 0.9 gram gold, including an 84-metre interval of 1.1 grams gold that upgrades the southwestern corner of the zone.

Hole 86 intersected 226 metres (from 226 metres) of 0.85 gram gold in what is described as a mineralized embayment in the barren central post-mineral intrusive. A 124-metre portion of the interval averaged 1.01 grams gold.

Mansfield in on track with its prefeasibility program on Lindero and anticipates a revised resource estimate by late 2007.

The existing resource at Lindero stands at about 30 million inferred tonnes grading 1.08 grams gold (just over 1 million contained ounces) in the MVZ, PVZ and Di P2 zones using a 0.6-gram gold cutoff grade.

The resource is contained in an area of just 600 by 200 metres, on the southeastern flank of the hill that is the Lindero intrusive. Mansfield drilling has since boosted the footprint of the deposit about threefold.

Gold mineralization at Lindero is mainly associated with quartz-magnetite stockworks and minor breccias or feeder structures hosted within the circular dioritic intrusive body.