Summary:
The Ashburton Gold Project is located on the northern margin of the Ashburton Basin and within the extents of the crustal scale Nanjilgardy Fault Zone that roughly traces the contact between the Ashburton Basin to the south and the underlying Hamersley Basin strata to the north. The project tenements are situated predominantly within the Wyloo Groups’ Mt McGrath Formation and Duck Creek Dolomite and the underlying Cheela Basalt and Beazley River Quartzite of the Shingle Creek Group.
Mineralisation
The primary structural controls for mineralisation at the historically mined pits are interpreted to be second order faults within the northwest trending Nanjilgardy Fault Zone that crosscuts the western end of the Diligence Dome and in bedding sub-parallel and high angle faults in the surrounding flanks of the Dome. The Project is situated along an axis of a distinct SE plunging antiform which has its southern limb truncated by a large sub-vertical NW-SE striking fault known as the Zoe Fault.
Mineralisation is hosted in siltstones, sandstones, conglomerates and dolomites of the Mt McGrath Formation and the Cheela Springs Basalt. The units dip to the south and around Mt Olympus the geology becomes complicated by folding and faulting. The base of oxidation at Mt Olympus is up to 100m below the original surface.
Mineralisation is structurally controlled and associated with minor sulphidic quartz veins and with zones of intense sulphides. Coarse grained, highly fractured pyrite (typically 5 to 15% of the rock) is the dominant sulphide with minor arsenopyrite and small amounts of chalcopyrite, digenite, covellite and tetrahedrite. Gold occurs as veinlets and blebs in pyrite.
Gold mineralisation occurs within broad, sulphidebearing shear zones developed along lithological contacts and competency contrasts in the sedimentary sequence7 . Two principal mineralised trends are recognised being a steeply south-dipping, discontinuous zone along the Zoe Fault, and a series of moderately southdipping sediment-hosted lodes north of the Zoe Fault, truncated to the northwest by basaltic units.
The sediment-hosted lodes thicken and increase in grade toward the Zoe Fault, with moderately south-plunging high-grade shoots developed at the intersection of the two trends. Mineralisation extends more than 950m down plunge, to depths exceeding 500m below the natural surface.
The majority of gold mineralisation is hosted within bedding-parallel zones in extensively fractured, altered and sulphidised coarse-grained sediments of the Mount McGrath Formation. These zones dip moderately (30–55°) to the southeast, with additional mineralisation in quartz veins.
The rocks have undergone pervasive sulphide–silica–sericite–hematite–carbonate alteration and are highly brecciated. Mineralisation at Mt Olympus is associated with minor sulphidic quartz veins and with zones of intense sulphide enrichment. Gold occurs as fine veinlets of 5– 10 microns enclosed within pyrite.
At West Olympus, mineralisation is predominantly developed within thick tensional quartz veins that cross-cut bedding-parallel shears, with additional mineralisation along the sediment-basalt contact is nearly always located within the sediment, some metres away from the contact itself.
Regional Exploration Potential
The Ashburton Gold Project’s sulphide-dominant mineralisation, centred on the Mt Olympus, Peake, and Zeus deposits.
Kalamazoo considers there are also major regional exploration opportunities to discover further sulphide and oxide gold resources within the Ashburton Project area. In particular, Kalamazoo plans to undertake extensive exploration and drilling across the following deposits and prospects:
• Peake Deposit - developed within a planar and steeply south dipping fault cutting mudstones and sandstones and shows significant continuous gold mineralisation over 2,000m strike that is open to the west 1,3. Historical mining has targeted shallow supergene enriched oxide gold to a maximum depth of 30m in a single 600m long open pit with 18koz @ 7g/t Au recovered. In the western half of the deposit, drilling becomes relatively sparse with no intercepts shallower than 80m below surface, with none testing the prospective shallow supergene zone. The current resource at the Peake Deposit is 210,000ozs @ 3.4g/t Au.
• Zeus Deposit - occurs within a south dipping package of coarse clean sandstone beds in the footwall of the Zoe Fault. The mineralised lode outcrops for over 800m along strike before plunging shallowly to the southeast along the contact with the Zoe Fault. The current 121koz @ 2.5g/t Zeus resource1 extends for 240m past the southeast extent of the open pit mine and further historical 80m to 100m spaced drill sections beyond that have extended the known mineralisation an additional 280m to the southeast at ~70- 100m depths.
• Waugh Deposit and Annie Oakley Prospect - the Waugh Deposit was a key focus in Kalamazoo’s 2020/21 drill programs due to its past production, current gold resource and having previously only been sparsely tested along strike or down dip. The Waugh Zone includes, in addition to the Waugh Deposit, several other prospects, such as the Annie Oakley Prospect, and Kalamazoo’s drilling has now extended this mineralised trend to approximately 2.5km trending to the north-west (and remains open). The current resource at the Waugh Deposit is 32,000oz @ 1.9g/t Au.
• Xanadu Ground – on 22 September 2025 Kalamazoo announced that it had acquired the adjoining Xanadu Gold Project tenements from Platina Resources Limited (ASX: PGM) (Platina) that are contiguous with, and along strike, of the AGP. The acquisition of the Xanadu Gold Project forms a key component of Kalamazoo’s regional growth strategy, which targets additional gold resources from both brownfield and greenfield prospects to support the Mt Olympus life-of-mine.