Antares, Mansfield hit new zone at Rio Grande (January 18, 2008)

Vancouver – Step-out drilling by Rio Grande joint venture partners Antares Minerals (ANM-V, ANMFF-O) and Mansfield Minerals (MDR-V, MFMNF-O) has identified significant copper-gold mineralization in a previously untested zone on the project located in northwestern Argentina’s Salta Province.

Hole RGA-07-056 cut 215 metres (essentially from surface) of 0.42% copper, 0.5 gram gold per tonne and 7.1 grams silver per tonne in the No. 7 zone located on the western margin of the project. The intercept includes a 48-metre interval grading 0.82% copper, 1.3 grams gold and 8.7 grams silver.

Mansfield director John Leask described hole 56 as “a big step-out on the west side” that could have significant tonnage implications. “It was a blind shot no geochem, no geophysics, no trenches, nothing a 700-metre step-out right in mineralization, right off the collar,” explained Leask.

No. 7 zone has a thicker colluvium cover than most of the Rio Grande project area giving very little outcrop as well as rendering soil sampling much less effective. Mineralization is open to the north, south and likely to the west as well. Like most of the mineralization encountered so far at Rio Grande, it is partially to completely oxidized and shows minimal transport of secondary copper minerals.

“With the discovery of encouraging copper-gold mineralization at the No. 7 zone, we have at least four areas where we have encountered longer runs of higher grade copper-gold mineralization,” states Antares president and CEO John Black in the news release. “These four areas have the potential to collectively host a significant volume of better grade mineralization and are interconnected by zones with lower grades.”

Antares-Mansfield drilling also tested the North and Sofia zones. Hole RGA-07-45 on the North zone – collared 150 metres east of similar mineralization in RGA-07-43 – cored 132 metres (from 128 metres downhole depth) grading 0.38% copper, 0.4 gram gold and 2.8 grams silver including 50 metres of 0.49% copper and 0.46 gram gold.

Hole RGA-07-50 on the Sofia zone returned 111 metres (from 114 metres downhole depth) of 0.42% copper, 0.41 gram gold and 8.5 grams silver. The intercept includes a 25-metre interval of 0.64% copper, 0.8 gram gold and 16.2 grams silver.

Copper-gold mineralization at Rio Grande is hosted in a sequence of intermediate sub-volcanic intrusives with variable degrees of potassic, calcic and propylitic alteration. Original chalcopyrite and magnetite mineralization occurs as disseminations and fracture fillings. Chalcopyrite has subsequently been oxidized, to varying degrees, to depths of at least 300-400 metres. Oxidation is typically in situ showing little to no copper remobilization.

Antares is operator at the 50-50 Rio Grande joint venture. In mid-2007 Mansfield completed a $5.25-million financing in Antares to hold about 9.8% of its partner.

Shares of Antares gained 12% on the January 18th drill news, closing up 41 at $3.91 apiece, while Mansfield posted a 10% gain to close up 35 at $3.70 per share.