MGX Resources has signed a formal agreement with Macmahon Underground for construction of the Groundrush underground decline at the Central Tanami Project Joint Venture in the Northern Territory.
The agreement, announced on 31 August 2026, covers work valued at approximately $38 million. MGX and Tanami Gold each hold a 50 per cent interest in the joint venture, which is targeting a project development decision in 2027.
Fourteen-month underground program
Macmahon's scope includes portal and ventilation establishment and development of the first 3.5 kilometres of decline to a depth of about 350 metres. The work is scheduled over 14 months.
Surface preparation is already underway at Groundrush, including establishment of laydown areas and re-opening the historic pit access ramp. Macmahon is due to mobilise for in-pit portal construction in September.
The decline will establish underground drilling platforms for a planned 33,000-metre resource-definition program. Drilling is expected to begin during the latter stages of decline construction and will test the Groundrush deposit to a depth of about 650 metres.
Resource conversion supports mine planning
The drilling program is designed to convert more than 400,000 ounces of Groundrush's Inferred Mineral Resource into the higher-confidence Indicated category for mine design and development work.
Groundrush currently contains 11.0 million tonnes at 3.3 grams per tonne gold for 1.2 million ounces. Across the broader Central Tanami joint venture, the reported Mineral Resource totals 31.0 million tonnes at 2.8g/t gold for 2.8 million ounces.
Resource-definition drilling also recommenced at the nearby Jims deposit in June. Jims contains 2.6 million tonnes at 2.7g/t gold for 220,000 ounces and is being assessed as a potential expanded open-pit ore source to supplement Groundrush.
Site activity and workforce requirements
Repairs and improvements are progressing at the accommodation camp and utilities areas near the historic central processing plant. Other infrastructure needed for the planned work is also being cleaned up and repaired.
MGX said recruitment of key site and project roles is underway. The combination of portal construction, underground development, surface infrastructure work and resource drilling points to a sustained requirement for experienced mining, technical and site-support personnel as the joint venture advances towards its 2027 development decision.
Source: MGX Resources Limited, “Groundrush Underground Decline agreement signed with Macmahon for the Central Tanami Project JV”, 31 August 2026.