Tanami Gold has completed blasting for the central and ventilation portals of the Groundrush Exploration Decline in the Northern Territory, moving the Central Tanami project into its next construction phase. The $38 million decline contract is designed to enable 33,000 metres of infill drilling targeting more than 400,000 inferred gold ounces.
- Central and ventilation portal blasting completed at Groundrush
- $38 million Macmahon contract covers 3.5km of decline development
- 33,000m infill drilling planned into the Groundrush gold deposit
- More than 400,000oz targeted for potential conversion from Inferred to Indicated
- Central Tanami development decision targeted for 2027
Groundrush portals reach construction milestone
Tanami Gold NL (ASX:TAM) has completed blasting for the central and ventilation portals of the Groundrush Exploration Decline, giving the Central Tanami Joint Venture a tangible construction milestone as it works towards a development decision targeted for 2027.
The work sits within the $38 million decline contract awarded to Macmahon Underground, which was announced in August and covers portal and ventilation establishment plus the first 3.5 kilometres of underground decline development. The contract is scheduled to run for 14 months and take the decline to a depth of about 350 metres.
Decline will unlock 33,000 metres of drilling
The decline is not yet a production project. Its immediate purpose is to provide underground access for 33,000 metres of infill resource-definition drilling at the Groundrush Gold Deposit. The drilling is intended to test whether more than 400,000 ounces currently classified as Inferred can be converted into the higher-confidence Indicated category for mine design and development work.
That programme will begin in the latter stages of decline construction, meaning the next important evidence will come from how the underground works progress and when drilling starts. The company has previously described the Groundrush decline mobilisation as part of a broader move into a more active development phase, but this announcement does not report a resource upgrade, Ore Reserve or production decision.
Large resource remains subject to definition work
Tanami and MGX Resources each hold a 50% interest in the Central Tanami Joint Venture. The joint venture’s cited JORC 2012 Mineral Resource totals 31.0 million tonnes at 2.8 grams per tonne gold for 2.8 million ounces, including 11.0 million tonnes at 3.3 grams per tonne for 1.2 million ounces at Groundrush.
Those figures are referenced from the November 2025 resource update and remain subject to the planned definition drilling and future technical work. The portal blast is therefore a project-execution signal rather than proof of mine economics: the key test will be whether the drilling supports the targeted classification upgrade and whether the joint venture reaches its proposed 2027 development decision.
Bottom Line?
Construction has moved from mobilisation to physical access, but the investment case still turns on decline delivery, drilling results and the quality of the eventual 2027 development decision.
Questions in the middle?
- Can Macmahon deliver the planned 3.5 kilometres of decline within the 14-month contract period?
- Will the 33,000 metres of infill drilling convert the targeted Inferred ounces into Indicated resources?
- What mine design, economic assumptions and funding requirements will underpin the 2027 development decision?