New quartz reef with visible gold at Maddens

ECR Minerals PLC

08 September 2026

 

The information contained within this announcement was deemed by the Company to constitute inside information as stipulated under the UK Market Abuse Regulation.

8 September 2026

ECR MINERALS PLC

("ECR Minerals", "ECR" or the "Company")

New quartz reef with visible gold at Maddens

Jack's Reef adds significant new exploration potential

ECR Minerals plc (LON: ECR), the exploration and development company focused on gold in Australia, is pleased to announce the identification of a new visible gold-bearing quartz reef at the Maddens Mine in the Maddens Gold Project in North Queensland ("Maddens"). ECR has a 50% interest in Maddens.

The newly recognised reef, named "Jack's Reef", was encountered during underground development work associated with ventilation infrastructure at the Maddens Mine.

The Board considers this to be particularly important, because Jack's Reef may indicate a key geological model linking the existing historic Maddens Mine workings and potential extensions of the broader mineralised system.

Highlights

·      New visibly gold-bearing reef discovered underground at the Maddens Mine, encountered during development works.

·      Jack's Reef is a consistent quartz structure, approximately 50 centimetres or more in width in places, with clearly visible gold observed within parts of the exposed reef.

·      Potential geological model: the position of Jack's Reef may explain why mineralisation appears to terminate at the northern end of the mine and could indicate a continuation or change in orientation of the existing Maddens Mine mineralised system due to structural controls.

·      New exploration opportunity: the discovery potentially opens up additional ground around the existing mine and towards the known Maddens Northern Lode for targeted exploration.

·      Existing mine infrastructure provides an important advantage, allowing the Company to investigate Jack's Reef from active underground workings rather than relying solely on surface exploration.

·      Production imminent: a significant amount of material from Jack's Reef is already stockpiled on surface, with processing activity expected to commence later this month.

Jack's Reef Discovery

Jack's Reef was encountered during development of an underground rise for the ventilation system at the Maddens Mine at the northern limit of the known mineralisation.

The reef is a consistent quartz structure, constrained within host-rock foliation, approximately 50 centimetres or more in width in places, with visible gold regularly observed within the quartz (see Fig 1. below). The exposed vertical extent of the reef is approximately 10 m in the rise and 5- 10 m along strike.

Fig. 1: Hand specimen from Jack's Reef showing visible gold (ringed)

Jack's Reef is considered particularly significant because of its locality and geological characteristics.

Recent three-dimensional surveying of the historic Maddens Mine workings shows that the existing mineralisation appears to terminate close to the area where Jack's Reef begins. The Maddens Mine's mineralisation mined to date cross-cuts host-rock foliation by about 30 degrees, whereas Jack's Reef follows foliation. Underground examination and surface exposures indicate that the Maddens Mine's mineralisation broadly changes bearing by 30 degrees clockwise at the northern end of the underground mine workings and becomes foliation-parallel over several horizons. The major manifestation of this orientation change is Jack's Reef. This form of structure is known as a "ramp and flat", where the structures "ramp" across foliation (as seen in the current Maddens Mine) and then exploit foliation-parallel weaknesses ("flats", or Jack's Reef) to propagate further. The Jack's Reef flat trends towards the Maddens Northern Lode and, although poorly exposed at only one site, appears to connect the Maddens Mine and the Maddens Northern Lode (see Fig, 2). The Maddens Northern Lode, a site of known mineralisation with significant historic underground workings, "ramps" (cross-cuts) foliation again, until a northern flat splay can be traced by pitting carried out by previous operators.

Fig. 2: Plan view of Maddens Ramp-Flat structure under 2026 Lidar imagery. Old workings indicated by Lidar confirmed by field visits.

The dimensions of the system are understood to be as follows:

Area	Structure	Horizontal length (m)
Maddens Mine	Ramp	60-90
Jack's Reef	Flat	120
Maddens Northern Lode	Ramp	70
North Flat	Flat	60

The south end of Maddens Mine also shows characteristics of entering into a flat. The North Flat has yet to be explored in any detail. All structures dip moderately to steeply west to south-west. The Board considers that the presence of ramp and flat structures at Maddens should significantly increase the exploration potential. In compressional structural regimes such as the Maddens project area, ramp-to-flat transitions create "dilatant" zones that can trigger gold deposition due to pressure drops and fracturing; at the same sites, permeability zones can form, with increased potential for high grades. Whilst mineralisation is not yet confirmed to be continuous across the whole system, the potential focus of high-grade zones at ramp-to-flat interfaces is considered by the Board to be a significant exploration advance, not only for the Maddens Mine but across the whole exploration tenement.

If confirmed through further work, the Board considers that this could materially increase the geological opportunity around the existing mine by demonstrating that gold-bearing structures continue beyond areas previously thought to represent the limits of historic development.

Jack's Reef gives ECR the opportunity to investigate potential additional mineralised areas at the Maddens Mine by targeted follow-up work from underground and/or a potential focused surface drill program. Such mineralised areas, if confirmed by continuity, thickness, and grade, could be accessed by stoping from current mine infrastructure with little additional development required.

The wider Maddens project tenements contain a number of historic mines and workings, and until now, there has been limited modern, systematic exploration to understand how these structures may be connected.

The identification of Jack's Reef therefore provides a potentially important new piece of the geological model and may help the Company build a clearer picture of the scale and continuity of the broader mineralised system.

Future Exploration Potential

The Company intends to continue to investigate Jack's Reef and undertake targeted follow-up work to better understand its orientation, continuity of dimensions and grade, and relationship with the existing Maddens Mine reef system.

This work will also consider whether similar structures may exist elsewhere around the historic mine area.

The Board believes the combination of visible gold, the consistent nature of the reef, its position relative to the existing workings, and the wider historic mineralisation across the Maddens project tenements creates a compelling opportunity for further exploration alongside ongoing mine development.

ECR Non-Executive Director Mike Parker commented: "Jack's Reef is one of the most exciting geological developments we have seen recently at Maddens. Not only does it form part of a much more extensive vein system than previously thought, but the ramp and flat structures form an excellent model for targeted high-grade delineation in the existing mines and for exploration models tenement-wide. The Maddens Mine appears to be on the same structure as Maddens Northern Lode, and where the ramp-flat interface occurs at the Northern Lode is a site of extensive previous mining on reportedly high-grades - exactly where the model predicts. We consider that the Maddens Northern Lode, as part of the main Maddens structure, can now be regarded as much more prospective,  potentially to a  similar extent as the Maddens Mine itself.

The Maddens Mine is already a highly prospective historic gold mine, but the discovery of Jack's Reef demonstrates why we believe there could be considerably more opportunity around the existing workings than has previously been recognised. Translating this structural model, and others we are developing, to the broader Maddens project tenements and other mine sites may reveal the true potential of the area, which formed part of our decision to acquire our 50% interest in this highly prospective, yet underexplored, project."

ECR Chairman Nick Tulloch added: "Jack's Reef is very encouraging and adds another dimension to the opportunity at the Maddens project.

"The presence of visible gold is clearly exciting, but just as importantly, the location and substantial nature of the reef may help us better understand how the mineralised system continues beyond the historic workings.

"This is exactly the type of finding we hoped the recent underground work and survey programme would begin to identify.

"Alongside this exploration upside, our immediate operational focus remains firmly on moving Maddens into production. A significant amount of material from both Jack's Reef and the main Maddens Mine is already stockpiled on surface and we expect processing activity to commence this month.

"We therefore have the combination of near-term production activity and a potentially important new geological opportunity developing at the same project."

Review of Announcement by Qualified Person

This announcement has been reviewed by Michael Parker, Non-Executive Director of ECR Minerals Plc. Michael Parker has a BSc. in Mining Geology and is a professional geologist and is a Fellow of the Australasian Institute of Mining and Metallurgy (FAusIMM). He is a qualified person as that term is defined by the AIM Note for Mining, Oil and Gas Companies.

FOR FURTHER INFORMATION, PLEASE CONTACT:

ECR Minerals plc	Tel: [phone]
Nick Tulloch, Chairman Andrew Scott, Director	[e-mail]
Website: www.ecrminerals.com
Allenby Capital Limited	Tel: [phone]
Nominated Adviser and Joint Broker Alex Brearley / Nick Naylor / Vivek Bhardwaj (Corporate Finance) Kelly Gardiner (Sales and Corporate Broking)	[e-mail]
OAK Securities Joint Broker Jerry Keen / Robert Bell	Tel: [phone]
Axis Capital Markets Limited	Tel: [phone]
Joint Broker
Lewis Jones
SI Capital Ltd	Tel: [phone]
Joint Broker
Nick Emerson
Brand Communications	Tel: [phone]
Public & Investor Relations
Alan Green

ABOUT ECR MINERALS PLC

ECR Minerals is a mineral exploration and development company operating through four wholly owned Australian subsidiaries ECR Minerals (Australia) Pty Ltd ("ECR Australia"), ECR Minerals (Queensland) Pty Ltd ("ECR Queensland"), ECR Minerals (Raglan) Pty Ltd ("ECR Raglan") and ECR Minerals (Paleogold) Ltd ("ECR Paleogold").

ECR Paleogold has a 50% interest in the Maddens hard rock mining project in Northern Queensland where work is underway for production this year.  It also has a 20% interest in the Salt Bush shallow open cut mining project in South Australia where preparations are underway for production which is expected to commence around mid-2027.  ECR Paleogold also owns 80% of the Tuckanarra exploration project in Western Australia.

ECR Australia owns the Bailieston and Creswick gold projects in central Victoria, Australia as well as the Tambo gold project in eastern Victoria.

ECR Raglan has a mining lease at the Raglan alluvial gold project in central Queensland, Australia and ECR Queensland has two approved exploration permits over the nearby Blue Mountain alluvial gold project.   ECR is currently working to bring the Blue Mountain alluvial gold project into production.  ECR Queensland also has three approved exploration permits covering 946 km² over a relatively unexplored area in Lolworth Range in northern Queensland. Furthermore, it has also submitted a licence application at Kondaparinga which is approximately 120km² in area and located within the Hodgkinson Gold Province, 80km NW of Mareeba, North Queensland.

Following the sale of the Avoca, Moormbool and Timor gold projects in Victoria, Australia to Fosterville South Exploration Ltd (TSX-V: FSX) and the subsequent spin-out of the Avoca and Timor projects to Leviathan Gold Ltd (TSX-V: LVX), ECR Australia has the right to receive up to A$2 million in payments subject to future resource estimation or production from these projects. 

ECR Australia also has approximately A$77 million of unutilised tax losses incurred during previous operations.

 

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