Phoenix Ridge is situated just north of the Company’s Beresford and Allanson underground mines, as part of the Westralia mining area and lies approximately 16km from the MMGO treatment plant (see Figure 1).
Phoenix Ridge was discovered in early 2019 following a broad spaced diamond drilling program designed to test the interpreted position of D3a and D3b structures below and to the north of the historic Morgans North open pit. In June 2019, the discovery was announced (see ASX 20 June 2019), with significant intercepts including:
Following the initial discovery, the Company quickly set out to complete a series of 80m by 80m spaced holes across the project and a maiden underground Inferred Mineral Resource of 841,000t @ 8.1g/t Au for 125,000oz was released (see ASX 3 October 2020).
Immediately after the release of the Phoenix Ridge Inferred Mineral Resource, the Company commenced a 40m by 40m spaced diamond infill program. Infill results confirmed the high grade potential of the deposit (see ASX releases 25 November 2019 and 24 July 2020).
The Company has now completed the infill drilling program, including a tighter 20m by 20m spaced program in the core of the deposit. An updated Mineral Resource estimate is scheduled to be released.
Phoenix Ridge is a BIF hosted underground deposit. The deposit is situated within the same stratigraphic sequence as the Beresford and Allanson underground deposits. Mineralisation is characterised by pyrite and/or pyrrhotite replacement of magnetite within the BIF host along with chlorite alteration and /or infill either within or adjacent to sites of brittle deformation within the BIF, this includes faults, fractures and fine veins.
High grade mineralisation is structurally controlled by the interaction of both steep east-south-east dipping D3a and shallow east dipping shears D3b shears and faults (both structures are prolific across the Westralia mining area) with more local structural complexities including moderate south-east dipping normal faults and shallow to steeply plunging folds.
The Phoenix Ridge deposit forms a key part of the Company’s re-optimisation work across its underground deposits.