MGO is located in the Achaean Murchison Province, a granite-greenstone terrane in the northwest of the Yilgarn Craton. Greenstone belts trending north-northeast are separated by granite-gneiss domes, with smaller granite plutons also present within or on the margins of the belts.

The Paddy’s Flat area is located on the western limb of a regional fold, the Polelle Syncline, within a sequence of mafic to ultramafic volcanics with minor interflow sediments and banded iron-formation. The sequence has also been intruded by felsic porphyry dykes prior to mineralisation. Mineralisation is located along four sub-parallel trends at Paddy’s Flat which can be summarized as containing three dominant mineralisation styles:
• Sulphide replacement BIF hosted gold. Quartz vein hosted shear-related gold.
• Quartz-carbonate-sulphide stockwork vein and alteration related gold.

The Yaloginda area is a gold-bearing Archaean greenstone belt situated ~15km south of Meekatharra. The deposits in the area are hosted in a strained and metamorphosed volcanic sequence that consists primarily of ultramafic and high-magnesium basalt with minor komatiite, peridotite, gabbro, tholeiitic basalt and interflow sediments. The sequence was intruded by a variety of felsic porphyry and intermediate sills and dykes.

The Reedy’s mining district is located approximately 15 km to the south-east to Meekatharra and to the south of Lake Annean. The Reedy gold deposits occur with- ........

For FY22, the Bluebird plant received underground ore from the Paddy’s Flat, South Emu - Triton and Bluebird underground mines and supplementary low grade stockpiles.

The Bluebird underground mine has been expanding rapidly since recommencement of mining in mid FY22, with further extensions and opportunities being identified. Overall expansion plans are being developed to determine the true potential of this asset.

With the expansion of Bluebird underground, at the end of FY22 Westgold paused operations at South Emu - Triton in the Reedy’s area to reassess its economics.

Open Pit
A majority of the open pits have a final design wall angle of 39-46 degrees. Dilution of the ore through the mining process has been accounted for within the Ore Reserve quoted inventory. Various dilution ratios are used to represent the style of mineralisation. Minimum mining widths have been accounted for in the designs, with the utilisation of 40t or 90t trucking parameters depending upon the size of the pit excavation.

Underground
In large disseminated orebodies sub level caving, sub level open stoping or single level bench stoping production methodologies are used. In narrow vein laminated quartz hosted domains a conservative narrow bench style mining method is used. In narrow flat dipping deposits a Flat Long Hole process is adopted (with fillets in the footwall for rill angle) and or jumbo stoping. Minimum mining widths have been applied i ........

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