Key Highlights

  • Blasting of the Central and ventilation portals for the Groundrush exploration decline has been completed.
  • The decline is being built under a $38 million contract with Macmahon Underground over 14 months, covering 3.5km of development.
  • Underground infill drilling of 33,000m is planned to convert more than 400,000oz of Inferred resources into the Indicated category.
  • The joint venture, owned 50% each by Tanami and MGX, is seeking a development decision in 2027.

Tanami Gold NL (ASX:TAM) has reported that blasting of the Central and ventilation portals for the Groundrush exploration decline has been completed at the Central Tanami Project Joint Venture in the Northern Territory. The announcement dated 11 November 2026 comes as the joint venture, which is 50% owned by Tanami and 50% by MGX Resources Limited (ASX:MGX), works towards a development decision in 2027.

The decline and its contract

Construction of the portals is part of the initial works under a $38 million contract with Macmahon Underground Pty Ltd, a Wholly Owned Subsidiary of Macmahon Holdings Limited (ASX:MAH). The contract covers portal and vent establishment and the first 3.5km of decline to a depth of about 350m, over a period of 14 months.

The company said the decline will give underground access to the Groundrush Gold Deposit for infill drilling. Tanami said the work is a key milestone for the joint venture.

Why the drilling matters for the resource

The joint venture’s JORC 2012 resource totals 31.0Mt at 2.8 g/t gold for 2.8Moz of contained gold. Within that, Groundrush holds 11.0Mt at 3.3 g/t for 1.2Moz.

The 33,000m infill program aims to convert more than 400,000oz of Inferred resource into the higher-confidence Indicated category, for mine design and development purposes. The drilling will begin in the later stages of the decline construction.

Timing and dependencies

The decline is scheduled to take 14 months, so underground infill drilling will not start until that work is well advanced. The development decision is targeted for 2027, and the timing of the infill results will determine how much of the Inferred resource can be classified as Indicated before then.

The Inferred resource is by definition less certain than Indicated material, and the reclassification depends on drilling results that have not yet been reported. Decline construction also carries engineering and schedule risk that the company will need to manage.

Final Word

The Groundrush portals mark a practical step for the joint venture, moving the project from surface work into underground access. The pace of decline development and the results from the infill drilling will decide how much of the Inferred resource can be upgraded ahead of the 2027 development decision.