Sheffield Resources Ltd.
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Sheffield Resources Ltd.

August 14, 2007 15:40 ET

Sheffield Reports 2.54% Copper Over 44 Metres

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Aug. 14, 2007) - Sheffield Resources Ltd. ("Sheffield") (TSX VENTURE:SLD)(PINK SHEETS:SLDOF)(FRANKFURT:S2Q) is pleased to announce the first assay results from the ongoing diamond drill program focused on the Engels Mine copper prospect at the Moonlight Copper Project located in Plumas County, California.



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COPPER LENGTH FROM TO
DRILL HOLE (%) (metres) (metres) (metres)
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07-E-1 2.95% 54 (177.2 feet) 0.0 54.0
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07-E-2 2.54% 44 (144.4 feet) 0.0 44.0
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07-E-3 2.99% 28 (91.9 feet) 0.0 28.0
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The first core hole, number 07-E-1, averaged 2.95% copper from the surface to 54m. The hole intersected a void at 58 metres of depth and was halted due to lost circulation. The mineralization occurs in two principal intervals. The upper interval is from the surface to 18m and averaged 3.16% copper including higher-grade intervals of 2.67% copper (from 6m to 8m), 7.12% copper (from 8m to 10m), 3.52% copper (from 10m to 12m), 4.57% copper (from 12m to 14m) and 6.87% copper (from 14m to 16m). The interval from 11m to 15m was broken and is believed to, in part, be stope fill. The second interval started at 26m of depth and continued to 54m and averaged 3.64% copper. This latter interval included higher-grade intervals as follows: 4.04% copper (from 26m to 28m), 6.58% copper (from 28m to 30m), 6.52% (from 30m to 32m), 4.33% copper (from 32m to 34m), 7.04% copper (from 34m to 36m), 5.72% copper from 36m to 38m, 10.9% copper (from 38m to 40m) and 2.34% copper (from 40m to 42m). The interval from 26m to 42m averaged 5.97% copper, including 15m interval consisting of broken rock and stope fill.



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COPPER LENGTH FROM TO
DRILL HOLE (%) (metres) (metres) (metres)
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07-E-1 2.95% 54 0.0 54.0
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Including interval 3.16% 18.0 0.0 18.0
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Which also includes 2.67% 2.0 6.0 8.0
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and 7.12% 2.0 8.0 10.0
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and 3.52% 2.0 10.0 12.0
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and 4.57% 2.0 12.0 14.0
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and 6.87% 2.0 14.0 16.0
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Including interval 3.64% 28.0 26.0 54.0
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Which also includes 4.04% 2.0 26.0 28.0
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and 6.58% 2.0 28.0 30.0
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and 6.52% 2.0 30.0 32.0
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and 4.33% 2.0 32.0 34.0
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and 7.04% 2.0 34.0 36.0
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and 5.72% 2.0 36.0 38.0
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and 10.9% 2.0 38.0 40.0
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and 2.34% 2.0 40.0 42.0
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Diamond drill hole number 07-E-2 averaged 2.54% copper over a length of 44 metres including an interval from the surface to 34m that averaged 1.21% copper and a second interval from 36m to 44m that averaged 8.84% copper including two metres of 19.15% copper (from 36m to 38m) and two metres of 14.85% copper (from 38m to 40m). The hole was drilled to 44m where it lost circulation in a disused mine adit.



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COPPER LENGTH FROM TO
DRILL HOLE (%) (metres) (metres) (metres)
---------------------------------------------------------
07-E-2 2.54% 44 0.0 44.0
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Including interval 8.84% 8.0 36.0 44.0
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Which also includes 19.15% 2.0 36.0 38.0
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and 14.85% 2.0 38.0 40.0
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Diamond drill hole 07-E-3, from the surface to 28 metres, averaged 2.99% copper including higher grade intervals of 4.62% copper (from 12m to 14m), 10.8% copper (from 14m to 16m), 7.8% copper (from 16m to 18m) and 5.19% copper (from 18m to 20m). The hole lost circulation at a depth of 32 metres when it encountered stope fill in the old Engels Mine.



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COPPER LENGTH FROM TO
DRILL HOLE (%) (metres) (metres) (metres)
---------------------------------------------------------
07-E-3 2.99% 28 0.0 28.0
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Including interval 7.1% 12.0 20.0 8.0
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Which also includes 4.62% 2.0 12.0 14.0
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and 10.8% 2.0 14.0 16.0
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and 7.8% 2.0 16.0 18.0
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and 5.19% 2.0 18.0 20.0
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All holes drilled in the ongoing diamond drill program are HQ gauge. The drill holes reported herein are the first modern drill holes from the Engels Mine area which is one of four principal target areas on the Moonlight Copper Project.

A National Instrument 43-101 compliant report on the Moonlight Deposit was earlier announced in a press release dated March 27, 2007. The deposit is open to resource expansion laterally and to depth.

Quality Control and Assurance

A rigorous Quality Control and Assurance program (QC/QA) is in place, including systematic inclusion of standard sample materials, blank samples, duplicate samples and inter-laboratory check assaying.

Samples are sent in sealed containers to ALS Chemex in Reno, Nevada. ALS Chemex is a recognized ISO 9000 registered laboratory. The control samples and duplicate assay results received for the drilling program demonstrated to Sheffield Resources that the assay results reported herein are reliable.

The exploration program is managed by Robert Wetzel, a California registered professional geologist and qualified person. David M Jenkins, P.Geo., and president of Sheffield Resources is designated the qualified person for the Moonlight Copper Project.

About Sheffield Resources Ltd.

Sheffield Resources Ltd. is an exploration and development company focused on the acquisition and systematic development of copper and nickel/cobalt deposits with potential for large tonnages of ore that are located close to infrastructure in politically stable areas.

This news release may contain forward-looking statements including but not limited to comments regarding the timing and content of upcoming work programs, geological interpretations, receipt of property titles, potential mineral recovery processes etc. Forward-looking statements address future events and conditions and therefore involve inherent risks and uncertainties. Actual results may differ materially from those currently anticipated in such statements. Sheffield Resources Ltd. relies upon litigation protection for forward-looking statements.

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