Mansfield Minerals Inc.
TSX VENTURE : MDR

Mansfield Minerals Inc.

March 26, 2008 17:00 ET

Mansfield Minerals Inc.: Rio Grande Update

VANCOUVER, BRITISH COLUMBIA--(Marketwire - March 26, 2008) - Mansfield Minerals Inc. (TSX VENTURE:MDR) -

Mansfield Minerals Inc. (the "Company") announces final drilling results on its 50% owned Rio Grande project located in Salta Province, northwestern Argentina. Holes RGA-07-57 to RGA-07-62 and RGA-07-32A are the remaining results generated from the 35 hole drill campaign which included highlights as follows.

- RGA-07-34 (Sofia North Zone): 189 m with 0.70% Cu and 0.67 g/t Au

- Includes 27 m with 1.16% Cu and 1.59 g/t Au

- Includes 12 m with 2.2% Cu and 1.85 g/t Au

- RGA-07-40 (Discovery Zone): 102 m with 0.58% Cu, 0.75 g/t Au, and 13.1 g/t Ag

- Includes 25 m with 1.37% Cu, 1.89 g/t Au, and 18.0 g/t Ag

- RGA-07-43 (North Zone): 151 m with 0.40% Cu, 0.46 g/t Au, and 12.4 g/t Ag

- RGA-07-56 (#7 Zone): 135 m with 0.53% Cu, 0.65 g/t Au, and 8.9 g/t Ag

- Includes 48 m with 0.82% Cu, 1.28 g/t Au, and 8.7 g/t Ag

This 35 hole campaign was designed as a scout program to establish the extent of copper-gold mineralization present at Rio Grande. Given the wide spread spacing of the drill holes and the number of strong intercepts, management is confident that Rio Grande has a large metal budget. A 15,000 metre follow-up drill campaign is currently being executed by Antares Minerals Inc. ("Antares"), and is designed as a step-out program focused on the #7, Sofia, Sofia-Discovery and North zones.

Results from the final 7 holes of the previous program are as follows.



-----------------------------------------------------------------------
Drill Hole Copper Gold Silver
Number Zone Interval Length (%) (g/t) (g/t)
-----------------------------------------------------------------------
RGA-07-57 Sofia North 312-332 m 20 m 0.30 0.33 3.1
414-432 m 18 m 0.36 0.34 9.3
-----------------------------------------------------------------------
9-170 m 161 m 0.34 0.32 3.2
RGA-07-58 #7 incl. 112-128 m 16 m 0.65 0.72 5.2
incl. 144-156 m 12 m 0.47 0.61 5.5
and 309-350 m 41 m 0.21 0.25 15.4
-----------------------------------------------------------------------
6-22 m 16 m 0.55 0.48 6.4
and 57-71 m 14 m 0.33 0.37 2.3
and 88-108 m 20 m 0.26 0.28 2.3
RGA-07-59 #7 and 116-153 m 37 m 0.54 0.54 7.7
incl. 138-148 m 10 m 1.07 1.15 19.5
and 190-214 m 24 m 0.24 0.21 2.6
and 256-266 m 10 m 0.24 0.23 3.4
and 553-585 m 32 m 0.18 0.30 4.1
-----------------------------------------------------------------------
RGA-07-60 Sofia 242-349 m 107 m 0.42 0.33 5.9
incl. 299-336 m 37 m 0.64 0.48 6.3
-----------------------------------------------------------------------
RGA-07-61 Southwest No significant intervals to report -
drill hole lost prior to target depth.
-----------------------------------------------------------------------
96-108 m 12 m 0.05 0.16 1.5
RGA-07-62 Northeast 225-251 m 26 m 0.14 0.13 4.8
262-276 m 14 m 0.11 0.08 1.2
-----------------------------------------------------------------------
RGA-07-32A Discovery 308-346 m 38 m 0.25 0.18 pending
364-374 m 10 m 0.37 0.32
-----------------------------------------------------------------------
- intervals have been rounded to the nearest metre.


In addition to the copper-gold mineralization encountered in holes RGA-07-57 and RGA-07-60, significant molybdenum mineralization was also noted (83.4 m with 0.054% Mo from 107-190 m in RGA-07-57 and 56 m with 0.033% Mo from 400-456 m in RGA-07-60). Follow-up drilling in this portion of the deposit will be required to determine the extent of the molybdenum mineralization.

A map of the drill hole locations has been posted on the Company's website and can be viewed at http://www.mansfieldminerals.com/s/RioGrande.asp.

Security - Chain of Custody and Quality Control

Antares' security, chain of custody and quality control is described on their website and can be reviewed at: www.antaresminerals.com/BestPractices/SamplingMethodologies/tabid/88/Default.aspx.

This news release has been reviewed by Gordon P. Leask, P.Eng., President of the Company, and a Qualified Person ("QP") as defined by National Instrument 43-101 (Standards of Disclosure for Mineral Projects).

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).

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 does not accept responsibility for the adequacy or accuracy of this release.

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