The Mt Magnet project is located within the north-south striking Meekatharra-Mt Magnet greenstone belt of the Western Australian Murchison Province. The greenstone belt lithologies comprise a succession of steeply dipping and intensely deformed plus interlayered mafic and ultramafic extrusive and intrusive rocks, felsic volcanics and banded iron formations (BIF). Granitic rocks intrude the greenstone belt stratigraphy.

Banded iron formations are the dominant host rocks for gold mineralisation in the project. Gold mineralisation is typically associated the pyrite & pyrrhotite replacement of magnetite in the banded iron. High-grade ore shoots are developed along the intersection of the BIF and a swarm of northeast trending faults, colloquially referred to as Boogardie Breaks.

Significant gold mineralisation is also found in porphyritic felsic units of the Boogardie Basin. Mineralisation generally occurs as a stockwork style of sericite-silica-pyrite veining and alteration within felsic porphyry units intruded into ultramafic flow sequences. Gold mineralisation tends to occur along felsic margins adjacent to the ultramafic contact. The Cosmos area consists of this style.

The Mt Magnet production centre includes the multi pit / underground projects of the Mt Magnet Gold Mine along with high grade underground ore which is hauled from the Vivien and Penny Gold Mines (with commercial production from Penny expected for the 2023 financial year onwards).

Eridanus, Morning Star and most Mt Magnet deposits, Rebecca, Tampia, Symes & Marda are modelled as open pit deposits. Factors include potential pit depths, minimum mineralisation widths and economic cutoffs based on current contract mining equipment and milling facilities. UG deposits, including Galaxy, Hill 60, Shannon, Vivien, Edna May lodes and Penny are modelled with consideration of extraction by conventional sub-level open stoping methods. Edna May, Galaxy and Eridanus models are generated as bulked low grade models for open pit evaluation and bulked underground mining scenarios.

MINING – MT MAGNET GOLD MINE
Operations at the Mt Magnet Gold Mine focussed on one open pit (Eridanus) and two underground mines (Shannon and Hill 60) during the year. A summary of the mine operations for the year is provided below:

Eridanus Open pit
The large Eridanus open pit was the main source of ore feed for the Mt Magnet production centre for the year making up 45% of the mill feed.

Eridanus was the sole open pit mine at Mt Magnet during the year with a total of 1,596kt of ore being mined at a grade of 1.10g/t for contained gold of 56,472 ounces.

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