Mansfield Minerals Inc.
TSX VENTURE : MDR

Mansfield Minerals Inc.

October 25, 2007 19:00 ET

Mansfield Minerals Inc.: Drilling Expands Rio Grande

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Oct. 25, 2007) - Mansfield Minerals Inc. (the "Company") (TSX VENTURE:MDR) announces that its joint venture partner, Antares Minerals Inc. ("Antares"), has reported results from an additional eight holes (4,094 metres) of the ongoing 15,000 metre drilling program at the Rio Grande copper-gold project in northwestern Argentina. Highlights of the holes include the discovery of significant copper-gold mineralization in the previously un-drilled North Zone and the intersection of a higher grade zone in RGA-07-040 at the northern end of the Discovery Zone. Some of the more significant intercepts are as follows:

- RGA-07-040 (Discovery Zone): 102.80 m with 0.58% Cu, 0.75 g/t Au, and 13.1 g/t Ag

- Includes 25.20 m with 1.37% Cu, 1.89 g/t Au, and 18.0 g/t Ag

- RGA-07-043 (North Zone): 151 m with 0.40% Cu, 0.46 g/t Au, and 12.4 g/t Ag

- RGA-07-048 (North Zone): 152 m with 0.44% Cu and 0.41 g/t Au (Ag pending)

- Includes 60 m with 0.54% Cu and 0.53 g/t Au (Ag pending)

- Within long intercept of lower grade - 428 m with 0.30% Cu and 0.29 g/t Au

Thirty holes (14,040 metres) have been completed to date and three drill rigs are currently operating. The first eight drill holes (3,574 metres) of the program were previously announced on September 14, 2007 and assays are pending on the remaining fourteen holes.

Five of the eight holes were completed in the Sofia and Discovery zones and were primarily drilled to test for extensions of mineralization to depth and to increase the drill-hole density at the northern end of the Discovery zone. Three of the holes were drilled into the previously un-drilled North zone. All holes through RGA-07-043 are reported. RGA-07-048 was split and analyzed prior to holes RGA-07-044 through RGA-07-047 due to the extensive length of mineralization encountered in the hole and the appearance of different styles of mineralization in the primary sulphide zone. Seven of the eight holes reported here intersected copper-gold mineralization.

Gordon P. Leask, President of Mansfield Minerals Inc. commented as follows:

"2007 is proving to be a pivotal year in the evolution of the Rio Grande project. We have reported RGA-07-34 (189 m grading 0.70% Cu and 0.67 g/t Au), discovered a new zone of mineralization in the North zone (RGA-07-43 and RGA-07-48), and have drilled the best intercept at the Discovery zone (RGA-07-40) to date. On a scout drilling basis, the percentage of holes to date that have intersected high grades over wide widths is exceptional."

John Black, President and CEO of Antares Minerals Inc. commented as follows:

"We continue to be pleased with the results from the current 15,000 metre drilling program at Rio Grande. We are particularly encouraged by the discovery of extensive copper-gold mineralization in the first few holes into the North zone. This opens up an entirely new area that warrants considerable follow-up drilling over the next few months. The higher grade mineralization encountered in RGA-07-040 is also promising as it demonstrates that the Rio Grande system is capable of producing zones with higher copper-gold grades. The current drilling program will be extended through to near year end and we are currently working with our partners, Mansfield Minerals, to plan an extensive follow-up program to commence with the new year."



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Mansfield Minerals Inc.
Rio Grande Project, Northwestern Argentina
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Drill
Hole Copper Gold Silver
Number Zone Interval Length (%) (g/t) (g/t)
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RGA-07-36 Discovery Deep 316-505 m 189 m 0.28 0.23 1.9
incl. 316-364 m 48 m 0.50 0.37 3.1
incl. 374-392 m 18 m 0.44 0.22 1.6
incl. 419-428 m 9 m 0.37 0.46 2.1
incl. 497-505 m 8 m 0.25 0.31 1.7
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RGA-07-38 Sofia Deep 319-326 m 7 m 0.76 0.99 9.3
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RGA-07-39 Discovery 16-239 m 223 m 0.31 0.31 1.6
incl. 16-113 m 97 m 0.30 0.42 1.4
incl. 47-72 m 25 m 0.38 0.51 3.2
incl. 127-161 m 34 m 0.37 0.20 2.2
incl. 167-187 m 20 m 0.66 0.27 2.4
incl. 199-239 m 40 m 0.28 0.31 1.9
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RGA-07-40 Discovery 263-365 m 102 m 0.58 0.75 13.1
incl. 267-285 m 18 m 0.62 0.72 28.9
incl. 323-348 m 25 m 1.37 1.89 18.0
incl. 357-365 m 8 m 0.47 0.62 7.6
and 448-458 m 10 m 0.42 0.50 6.7
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RGA-07-41 Discovery 135-264 m 129 m 0.29 0.38 4.1
incl. 135-183 m 48 m 0.38 0.56 5.2
incl. 147-173 m 26 m 0.47 0.73 6.5
incl. 193-264 m 71 m 0.25 0.29 3.5
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RGA-07-42 North No significant intervals to report.
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RGA-07-43 North 3-154 m 151 m 0.40 0.46 12.4
incl. 5-48 m 43 m 0.44 0.47 12.1
incl. 60-76 m 16 m 0.73 0.84 32.8
incl. 108-122 m 14 m 0.71 0.83 14.0
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RGA-07-48 North 131-559 m 428 m 0.30 0.29 Pending
incl. 131-162 m 31 m 0.37 0.35 Pending
incl. 270-422 m 152 m 0.44 0.41 Pending
incl. 304-364 m 60 m 0.54 0.53 Pending
incl. 444-487 m 43 m 0.37 0.40 Pending
and 629-649 m 20 m 0.48 0.50 Pending
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- intervals have been rounded to the nearest metre.


For a comprehensive discussion of drilling results, please see Antares' news release dated October 25, 2007 at www.antaresminerals.com. A map of the drill hole locations has been posted on the Company's website and can be viewed at www.mansfieldminerals.com/s/RioGrande.asp.

This news release has been reviewed by John Black, Antares' President, who serves as the qualified person (QP) under the definitions of National Instrument 43-101. Antares' security, chain of custody and quality control is described on their website and can be reviewed at: www.antaresminerals.com/bestpractices_samplingmethodologies.asp.

About Mansfield Minerals Inc.

Mansfield is a mining exploration company which has focused its activities in northwestern Argentina since August 1994. The Company's current significant properties and projects consist of mineral rights covering approximately 170 square miles in three Argentine provinces and one Canadian province. The Company is currently focused on two primary projects which include Lindero (gold) and Rio Grande (copper-gold). Antares is earning a 50% interest in the Rio Grande project from Mansfield and reports that it has recently completed the required expenditures and payments, and plans to vest its interest in the near future. Upon vesting, Antares will formalize a definitive joint venture agreement with Mansfield to fund ongoing exploration at Rio Grande on a 50/50 basis with Antares as operator.

On behalf of the Board of Directors,

Gordon P. Leask, P.Eng., President

Caution Regarding Forward-Looking Statements - This news release contains certain forward-looking statements, including statements regarding the business and anticipated financial performance of the Company. These statements are subject to a number of risks and uncertainties. Actual results may differ materially from results contemplated by the forward-looking statements. When relying on forward-looking statements to make decisions, investors and others should carefully consider the foregoing factors and other uncertainties and should not place undue reliance on such forward-looking statements. The Company does not undertake to update any forward looking statements, oral or written, made by itself or on its behalf.

The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this release.

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