Macarthur Minerals - Initial Hematite Inferred Mineral Resource Estimate
07/15/2010

Initial Hematite Inferred Mineral Resource Estimate

Online PR News – 15-July-2010 – – NEWS RELEASE Symbol: MMS-TSXV
June 22, 2010 For Immediate Dissemination

INITIAL HEMATITE INFERRED MINERAL RESOURCE ESTIMATE

VANCOUVER, BRITISH COLUMBIA – (Marketwire – June 22, 2010), Macarthur Minerals Limited (MMS – TSXV)(“the Company”) is pleased to release its NI 43-101 compliant initial Inferred Mineral Resource estimate for its Banjo and Moonshine North DSO (“Direct Shipping Ore”) projects, at its Lake Giles iron ore project located in Western Australia, of 4.4 million tonnes at 54.2 % Fe.

The new Inferred Mineral Resource estimate is based on recent drilling carried out at the Lake Giles project and is the Company’s inaugural Inferred Mineral Resource estimate (refer table 1) for surface hematite-goethite mineralisation. The resource was modelled by independent mining consultancy group CSA Global Pty Ltd (“CSA”) using the Company’s geological interpretation.

Table 1 – Lake Giles – Initial NI 43-101 Hematite-Goethite Inferred Resource Estimate based on 50% Fe cut-off is:

Tonnes
(Mt) Fe% P% SiO2% Al2O3% LOI %
4.4 54.2 0.068 10.69 4.90 7.00

• Figures contained within Table 1 have been rounded.
• Resource estimated over a combined strike length of 3km for both projects.
• A block model was constructed using three dimensional geological wireframes.
• Outlines and wireframes honour the actual locations of contacts on drill holes that are off section.
• A density estimate of 3.7 t/m3 was applied, based on surface samples.

The resource is based on the first 32 RC drill holes and further drilling is required to define the limits of the mineralisation at Banjo. Macarthur Minerals President, Mr Alan Phillips, stated “This is a pleasing result given the prospect was only discovered earlier this year, and we are at the infancy of understanding of the hematite geology in the region and our team is confident that its objective to delineate 10mt from the existing identified prospects will be achieved ”.

Mr Phillips added “It is important to recognise that as the Company achieved its goal of delineating a 1Bt+ magnetite resource last year, commencing this year, the focus has been on quantifying the hematite potential in the region”.

After the delineation off the initial hematite mineral resource estimate a further 77 RC holes have been drilled on 7 projects and analytical results for this drilling are still pending. The additional 7 projects have been identified through ongoing mapping of the 25 geophysical DSO targets denoted by the exploration team (refer table 2). RC drilling and mapping is continuing.

Table 2 – Mapped outcropping hematite zone.

Project Mapped Strike Length (km)
South Central 1
Central 6
North Central 2
Snark 2
Woodcutters 0.5
Lost World 0.5
Sandalwood 3
Total 15

Diamond Drilling and Metallurgical Testwork

A diamond drilling programme has commenced to provide suitable material for a comprehensive metallurgical testwork programme and is scheduled to commence late July. It is likely that completion of this programme will trigger the commencement of a pre feasibility study to be undertaken by Engenium Pty Ltd. Engenium has an impressive track record with emerging and established resource companies in the mining and iron ore sector.

Quality Assurance and Quality Control (QAQC)

Intersections reported have been verified by the Company’s QAQC protocols. All samples from drill holes are prepared by SGS Laboratory and pulverised to 90% passing 75 microns then analysed for the iron suite using XRF.

QUALIFIED PERSON

Mr. Chris Allen, MAIG, who is a full-time employee of CSA and is an Independent Qualified Person, has reviewed and approved the above technical information relating to Mineral Resource estimates contained in this release.

Mr. Andrew Spinks B.App.Sc, Grad.Dip (Mining), a member of AusIMM, and a consultant geologist, is a Qualified Person as defined in National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"), in charge of the exploration on the Lake Giles project.

Further information on Macarthur Minerals Limited and technical reports on the Lake Giles project can be found on the Company’s website www.macartherminerals.com or www.sedar.com

On behalf of the Board of Directors,
MACARTHUR MINERALS LIMITED

“Alan Phillips”
Alan Phillips, President, Chairman & CEO

Corporate Relations
David Taylor
Tel: (604) 687 0775, Email: macarthurminerals@capitalstreetgroup.com

Australia: Alan Phillips, Tel: +61 418 726 230
Email: strategiccapital@bigpond.com

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