Macarthur Minerals Limited
TSX VENTURE : MMS

Macarthur Minerals Limited

August 30, 2007 15:58 ET

Macarthur Minerals Limited: Potential Magnetite Iron Ore Project Lake Giles, Western Australia Project Update

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Aug. 30, 2007) - Macarthur Minerals Limited (TSX VENTURE:MMS) is pleased to provide the following update on its exploration activities at its 100% owned 1,155 km2 Lake Giles magnetite iron ore and base metals project in Western Australia.

Stage 4 Drilling Program

The Company has just signed a contract to drill a further 8,000 - 10,000 meters commencing in September 2007. This program will focus on the Iron Ore (FE) potential of the area with several holes being scheduled to be drilled in Nickel (NI) targets which have been identified from previous field work.

Stage 3 Drilling Program

The Company completed its Stage 3 Drilling Program in February/March 2007 and has now received all results. To date, a total of 42 RC drill holes have been completed for 7,746 meters and approximately 1,500 composite samples have been analyzed for multi elements, and approximately 250 composite samples have been submitted for Davis Tube analysis.

The current resource estimates are based on the 42 reverse circulation drill holes and the 7,746 meters of drilling. The drilling was completed in three phases as summarized in Table 1. (Refer more detail in table 2)



Table 1: RC drilling campaigns

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Phase Date Drill Holes Number of holes Meters
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One July 2006 LGRC01-07 7 937
Two August-September 2006 LGRC08-25 20 3,199
Three January-February 2007 LGRC25-42 15 3,310
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Total 42 7,446
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Initial Resource Estimation

Hellman & Schofield Pty Ltd (H&S) was commissioned by the Company to estimate resources for the Lake Giles magnetite iron ore project in the Yilgarn Craton of Western Australia. Three areas have been identified from the drilling as potential resource areas (See Figure 1 with detailed drilling location in Figure 2).

Newly Granted Mining Leases

The Company further advises that the following mining leases "M30/0206, M30/0207, M30/0208, M30/219, M30/0228 and M30/0229" have been granted by the Department of Mineral Resources. The scheduled Stage 4 drilling will also include exploring the newly granted mining leases. The Company noted that having had the above mining leases granted does give Macarthur a competitive edge over other junior explorers in the quest for additional funds and/or partners.

Strategic Development Partners

The Company has entered into discussions with potential development partners both locally and from the Asian region.

Qualified Person

Mr. Nick Revell, BSc, a member of AusIMM, and a Company director, 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.

On behalf of the Board of Directors,

MACARTHUR MINERALS LIMITED

David K Barwick, President, Chairman & CEO

ACN 103 011 436

NOTE: To view Figure 1 and Figure 2, please click the following link: http://www.ccnmatthews.com/docs/mms0830.pdf



Table 2: Inferred Mineral Resource Estimate by domain and drill hole

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Wireframe Head Concentrate
-------------------------------------------------------------
Density Mass Fe Mass Mass
Drill Volume -------------------------------------------------
Hole (m3) (t/m3) (Tonnes) (%) (Tonnes) Rec. %
---------------------------------------------------------------------------
Snark
---------------------------------------------------------------------------
LGRC01 785,497 3.24 2,541,810 26.74 571,339 22.5
-------------------------------------------------------------------------
LGRC02 809,966 3.30 2,676,767 31.01 738,164 27.6
-------------------------------------------------------------------------
LGRC08 1,288,311 3.23 4,159,126 28.74 1,050,904 25.3
-------------------------------------------------------------------------
LGRC11 1,908,302 3.34 6,379,094 30.47 1,601,832 25.1
-------------------------------------------------------------------------
LGRC14 1,959,899 3.30 6,465,463 29.55 1,402,102 21.7
-------------------------------------------------------------------------
LGRC16 743,510 2.98 2,212,764 16.32 304,498 13.8
-------------------------------------------------------------------------
LGRC40 633,723 2.97 1,879,827 16.68 254,280 13.5
-------------------------------------------------------------------------
Subtotal 8,129,208 3.24 26,314,851 27.49 5,923,119 22.5
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Clark Hill
North
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LGRC22 246,275 3.11 765,812 32.88 222,489 29.1
-------------------------------------------------------------------------
LGRC24 332,464 3.57 1,186,301 31.24 372,102 31.4
-------------------------------------------------------------------------
LGRC25 1,395,562 3.42 4,779,623 32.80 1,556,498 32.6
-------------------------------------------------------------------------
LGRC26 302,159 3.25 981,177 29.03 285,591 29.1
-------------------------------------------------------------------------
Subtotal 2,276,460 3.39 7,712,913 32.09 2,436,680 31.6
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Clark Hill
South
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LGRC18 3,688,414 3.38 12,450,447 30.16 4,032,945 32.4
-------------------------------------------------------------------------
LGRC33 7,386,528 2.96 21,831,765 16.15 3,030,479 13.9
-------------------------------------------------------------------------
LGRC37 4,545,537 3.13 14,226,113 23.35 3,040,302 21.4
-------------------------------------------------------------------------
Subtotal 15,620,479 3.11 48,508,325 21.86 10,103,726 20.8
---------------------------------------------------------------------------
Total 26,026,147 3.17 82,536,088 24.61 18,463,524 22.4
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---------------------------------------------------------------------------
Magnetic Concentrate
---------------------------------------------------------------------------
Fe Al2O3 SiO2 P MgO S LOI Cr
Drill -------------------------------------------------------------
Hole % % % % % % % %
---------------------------------------------------------------------------
Snark
---------------------------------------------------------------------------
LGRC01 65.39 0.16 8.13 0.03 0.42 0.14 -2.87 0.00
-------------------------------------------------------------------------
LGRC02 64.11 0.12 9.92 0.04 0.41 0.26 -2.19 0.00
-------------------------------------------------------------------------
LGRC08 57.11 0.17 18.52 0.02 0.20 0.02 -1.74 0.01
-------------------------------------------------------------------------
LGRC11 68.52 0.11 4.75 0.02 0.24 0.28 -3.03 0.01
-------------------------------------------------------------------------
LGRC14 65.61 0.14 7.81 0.03 0.51 0.50 -2.74 0.01
-------------------------------------------------------------------------
LGRC16 57.94 0.12 15.97 0.03 0.10 0.14 -1.95 0.02
-------------------------------------------------------------------------
LGRC40 65.36 0.53 7.02 0.08 0.39 0.33 -2.18 0.01
-------------------------------------------------------------------------
Subtotal 64.28 0.15 9.56 0.03 0.33 0.27 -2.52 0.01
---------------------------------------------------------------------------
Clark Hill
North
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LGRC22 65.08 0.09 9.02 0.02 0.29 0.03 -2.47 0.01
-------------------------------------------------------------------------
LGRC24 64.27 0.09 10.19 0.02 0.37 0.08 -2.66 0.01
-------------------------------------------------------------------------
LGRC25 65.26 0.08 8.69 0.01 0.26 0.02 -2.74 0.00
-------------------------------------------------------------------------
LGRC26 66.16 0.09 7.62 0.02 0.24 0.24 -2.91 0.00
-------------------------------------------------------------------------
Subtotal 65.20 0.09 8.83 0.01 0.28 0.05 -2.72 0.00
---------------------------------------------------------------------------
Clark Hill
South
---------------------------------------------------------------------------
LGRC18 62.00 0.07 12.58 0.02 0.77 0.05 -2.67 0.05
-------------------------------------------------------------------------
LGRC33 61.07 0.31 8.43 0.05 3.62 0.18 -1.80 0.60
-------------------------------------------------------------------------
LGRC37 62.25 0.19 10.33 0.05 1.64 0.47 -2.11 0.17
-------------------------------------------------------------------------
Subtotal 61.79 0.18 10.66 0.04 1.89 0.22 -2.24 0.25
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Total 63.04 0.16 10.06 0.03 1.18 0.21 -2.40 0.14
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