Macarthur Minerals Increases Direct Shipping "Ore Inferred Resource" by 57% to 18Mt

THIS NEWS RELEASE IS NOT FOR DISTRIBUTION TO UNITED STATES SERVICES OR FOR DISSEMINATION IN THE UNITED STATES

Macarthur Minerals Limited (TSX VENTURE:MMS) ("the Company") is pleased to release a 57% increase in the Hematite-Goethite Inferred Mineral Resource estimate for its Lake Giles DSO ("potential Direct Shipping Ore") projects located in Western Australia. The Inferred Resource estimate has increased to 18 million tonnes at 55.5% Fe (refer Table 1) based on the last resource statement of 11.5Mt at 55.2% Fe (Press Release Dated November 9, 2010).

The Mineral Resource estimate increase is due to the inclusion of Central and Banjo-Lost World projects where 4.8Mt at 55.2% Fe and 5.5Mt at 55.7% Fe have been estimated respectively.

The resource increases have been based on the recently completed Stage 9 programme and mineral estimates have been modelled by independent mining consultancy group CSA Global Pty Ltd ("CSA") using the Company's geological interpretation.

Table 1 - Goethite/Hematite (DSO) - Inferred Mineral Resource Estimate

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                       Tonnes      Fe%       P%    SiO2%   Al2O3%    LOI %
Deposit                   (Mt)
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Banjo-Lost World          5.5     55.7     0.07      8.1      4.7      7.1
Moonshine                 0.6     52.8     0.06     13.3      3.9      5.8
Central                   4.8     55.2     0.06      8.2      4.5      8.0
Snark                     7.1     55.9     0.07      7.8      4.2      7.6
--------------------------------------------------------------------------
Total                    18.0     55.5
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--  Figures contained within Table 1 have been rounded.
--  A block model was constructed using three dimensional geological
    wireframes.
--  Variograms were generated but were generally very poor due to limited
    data. Grades were estimated using ordinary kriging.
--  Outlines and wireframes honour the actual locations of contacts on drill
    holes that are off section.
--  Density was estimated with a regression from Fe grade based on core and
    rock samples.

Macarthur Minerals Director, Mr Alan Phillips stated, "This is an outstanding outcome and has far exceeded our objective of delineating 10mt. The increased tonnage has reduced the discovery cost per tonne to a mere 20 cents. We are making significant progress in our goal of bringing Lake Giles into initial production through our DSO resource."

Additional Targets and Opportunity to Increase DSO Mineral Resources

Macarthur Minerals has numerous targets and opportunities that may further increase the DSO resource base by extending the drilling program on known resources and drilling numerous untested targets that have been mapped.

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 Amdel and SGS Laboratories and pulverised to 90% passing 75 microns then analysed for the iron suite using XRF.

QUALIFIED PERSON

Mr. Chris Allen, BSc(Hons),MBA, 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.

ABOUT MACARTHUR MINERALS LIMITED (TSX VENTURE:MMS)

Macarthur Minerals Limited, is a Perth, Australia based resource development company that is currently focused on developing its Lake Giles Iron Ore project, located in the Yilgarn iron ore district in Western Australia. The Lake Giles project is located 110Km from rail with direct access to the Port of Esperance, Western Australia. The project has a 43 101 compliant resource of 1.1 Billion tonnes of Magnetite, and 18 Million Tonnes of Direct Shipping Ore (DSO) Hematite at 55.5% Fe. Macarthur is currently completing a scoping study on the Magnetite project and a pre-feasibility study on its DSO Hematite, both expected to be completed by year end 2010.

On behalf of the Board of Directors,

MACARTHUR MINERALS LIMITED

Alan Phillips, President, Chairman & CEO

Caution Regarding Forward Looking Statements

The forward-looking statements in this document reflect the current expectations, assumptions or beliefs of the Company based upon information currently available to the Company. With respect to forward-looking statements contained in this document, assumptions have been made regarding, among other things, the reliability of information prepared and/or published by third parties that is referenced in this document or was otherwise relied upon by the Company in preparing this document. Although the Company believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and no assurance can be given that these expectations will prove to be correct as actual results or developments may differ materially from those projected in the forward-looking statements. The term "ore" in DSO is not meant to imply economic viability has been established. Factors that could cause actual results to differ materially from those in forward-looking statements include unforseen technology changes that results in a reduction in iron or magnetite demand or substitution by other metals or materials, the discovery of new large low cost deposits of iron ore or magnetite and the general level of global economic activity. Readers are cautioned not to place undue reliance on forward-looking statements due to the inherent uncertainty thereof. Such statements relate to future events and expectations and, as such, involve known and unknown risks and uncertainties. The forward-looking statements contained in this document are made as of the date of this document. Except as may otherwise be required pursuant to applicable laws, the Company does not assume any obligation to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.

SOURCE: Macarthur Minerals Limited

The Buick Group Jonathan Buick Corporate Relations 416-915-0915 This email address is being protected from spambots. You need JavaScript enabled to view it. Macarthur Minerals Limited - Australia Alan Phillips +61 418 726 230 This email address is being protected from spambots. You need JavaScript enabled to view it. www.macartherminerals.com