MGX Resources and joint venture partner Tanami Gold have executed a $38 million agreement with underground mining contractor Macmahon to construct the Groundrush decline at their Central Tanami Project Joint Venture in the Northern Territory. The contract represents a significant commitment to development infrastructure, with on-surface works already underway and portal construction scheduled to commence in September 2026, signalling serious progress toward the partners’ stated goal of reaching a development decision in 2027.
The Groundrush decline will extend 3.5 kilometres over a 14-month construction period, reaching an initial depth of 350 metres. Beyond providing ore access, the underground workings will establish drilling platforms used to execute approximately 33,000 metres of infill drilling targeting the Groundrush Gold Deposit. The objective of this drilling campaign is to convert over 400,000 ounces of mineral resources currently classified as Inferred into the higher confidence Indicated category, a resource classification essential for supporting mine design and development feasibility studies.
The project is built on a mineral resource base of 31.0 million tonnes at an average grade of 2.8 grams per tonne gold, totalling 2.8 million ounces of contained gold. The Groundrush deposit specifically comprises 11.0 million tonnes at 3.3 grams per tonne, holding 1.2 million ounces. The planned drilling will extend resource definition to approximately 650 metres depth, significantly deeper than the initial decline development.
The Macmahon contract signals that the joint venture partners have achieved sufficient confidence in project geology and economics to deploy capital at this scale. A contractor engagement of this magnitude indicates that due diligence has progressed substantially beyond early exploration phases. The immediate commencement of portal construction in September 2026 provides a concrete near-term catalyst for project visibility.
Parallel workstreams support this development trajectory. Resource definition drilling continues at the Jims Gold Deposit, previously mined some 25 years ago but now considered to offer significant potential for the expanded Central Tanami operation. Site infrastructure improvements are being undertaken alongside recruitment for key operational and project roles, preparations consistent with scaling toward production.
The critical next milestone remains the infill drilling program itself. Results from the 33,000-metre campaign will substantially determine achievable mine economics and will likely prove decisive for the 2027 development decision timeline. Market attention should focus on the rate of resource conversion and any indication of mine life extension as drilling results emerge. This announcement is price sensitive and has been flagged as material by the ASX.
View the full ASX announcement (PDF)
About MGX Resources Limited (ASX: MGX)
MGX Resources Limited is an Australian mining company that primarily operates the Koolan Island hematite iron ore mine in Western Australia’s Kimberley region, with over 40 million tonnes of export history. The company is diversifying into precious and base metals exploration, including a 50% stake in the Central Tanami Gold Project in the Northern Territory, while maintaining exploration activities across Western Australia’s Mid-West and Gascoyne regions.
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