GreenX Metals Ltd - GreenX Uncovers Historical Estimate at Tannenberg

NEWS RELEASE  20 OCTOBER 2025 

GREENX UNCOVERS HISTORICAL ESTIMATE
AT TANNENBERG COPPER PROJECT

HIGHLIGHTS

·      1940 Historical Estimate of Significant Scale: Historical Estimate from 1940 identifies 728,000 tonnes contained copper (1,605 Mlbs) at an average grade of 2.6% copper in part of Tannenberg Project licence area discovered from original project data archives

o  Estimate based on a 1935-1938 National Socialist Government drilling campaign across four zones: Ronshausen, Hönebach, Wolfsberg and Schnepfenbusch

o  Drilling targeted the thin Kupferschiefer horizon only

o  Focused only on copper and did not include by-product metals

·      1984 Historical Estimate provides Validation: Independent company St Joe Exploration GmbH conducted limited drilling between 1980 and 1984, further validating the 1940 historical estimate

o  Drilling focused on only 28% of the Ronshausen zone but included by-product silver

o  Drilling identified up to 3.45m thick mineralisation straddling the Kupferschiefer and the limestone hanging wall and sandstone footwall above and below the Kupferschiefer

o  1984 historical estimate shows consistent grades of 2.1% copper plus 25 g/t silver with 169,000 tonnes of contained copper and 6.5 million ounces of silver

·      Exploration Upside Potential under Modern Interpretation: St Joe Exploration confirmed thicker widths of copper and silver mineralisation at Ronshausen, and more may exist up to 30m above and 60m below the Kupferschiefer in the limestone hanging wall and sandstone footwall

o  Hypothesis is consistent with modern understanding of the Kupferschiefer deposit model as demonstrated at KGHM's Polish mining operations which are also found on the same geological structure as the Tannenberg Project

·      Active Exploration Program: GreenX is currently relogging and resampling over 4km of archived core from 47 holes to upgrade historical data to modern standards

o  Investigation of German mining archives and the digitisation of original historical data continues

o  Planning of future twin drilling campaign to verify the historical estimates, and to establish a mineral resource estimate in accordance with the JORC Code (2012) (JORC Code)

·      Cautionary statement: The historical estimates in this announcement are not reported in accordance with the JORC Code. A competent person has not done sufficient work to classify the historical estimate as a mineral resource or ore reserve in accordance with the JORC Code. It is uncertain that following evaluation and/or further exploration work that the historical estimate will be able to be reported as a mineral resource or ore reserve in accordance with the JORC Code.

In addition, a later historical estimate from 1984 was produced by St Joe Exploration GmbH (St Joe), which covers a small part of the same area as the 1940 historical estimate (St Joe's historical estimate).

The St Joe's historical estimate is based on limited drilling between 1980 and 1984 (refer to announcements dated 2 August 2024 and 28 April 2025). St Joe's historical estimate provides further validation for the 1940s historical estimate.

Figure 1: Map showing the location of the zones of the historical estimates and historical mining operations

GreenX's Chief Executive Officer, Mr Ben Stoikovich, commented: "This represents a significant breakthrough in our archive search and fundamentally supports our exploration hypothesis of the Tannenberg mineral system. It demonstrates that extensive copper mineralisation was identified historically, but exploration at the time was constrained by the prevailing geological model, which focused solely on the thin Kupferschiefer shale and the urgent need to mine given the outbreak of World War II. The 1940 historical estimate, based on a narrow-mineralised interval and excluding by-product silver, was further validated by the 1984 work and modern understanding from Poland's Kupferschiefer mining operations, together confirming that copper mineralisation extends beyond the Kupferschiefer horizon and providing major proof of concept and clear alignment with GreenX's geological model. The implications are substantial, reinforcing the potential for a large-scale and high-grade brownfield copper project at Tannenberg, and underscoring the project's significance as a major European copper opportunity."  

1940 MANSFELD HISTORICAL ESTIMATE

The 1940 historical estimate was calculated by Mansfeld AG according to the relevant German standards applicable during that time. The 1940 historical estimate is based on 18 holes from the 95-hole database generated during the 1935 to 1938 drilling campaign. The original archive document established 728,000 tonnes of contained copper at an average grade of 2.6% copper between the Wolfsberg and Schnepfenbusch mines in the North and the Ronshausen area in the South (Figure 2). The historical estimate covers mineralisation from a depth of 100m in the North to 400m in the Southern end area near Ronshausen.

The 1940 historical estimate covers only the narrow width Kupferschiefer shale mineralisation, which is notable due to the mistaken belief at the time that copper was only present in the distinctive Kupferschiefer shale. Later exploration campaigns have found mineralisation over much wider thicknesses (see 1984 St Joe's historical estimate section below). This is consistent with GreenX's exploration hypothesis that historical exploration was mainly based on an outdated deposit model that focused on the 20-60 cm-thick Kupferschiefer shale horizon. The modern understanding of the Kupferschiefer deposit model now shows that up to 95% of mineable copper can be hosted in the footwall sandstone and hanging wall limestone, as evidenced at KGHM Polska Miedź S.A's Polish mining operations.

Figure 2: Map showing the locations of the zones of the 1940 historical estimate, related drill holes and historical mining operations

It is also noteworthy that the 1940 historical estimate did not include by-product silver mineralisation. The majority of the mineralisation (463,000 tonnes of contained copper) was found to be present in the Ronshausen region, with gradually decreasing amounts to the North, where the historical mining is to be found (See Table 1).

Cautionary statement: The historical estimates in this announcement are not reported in accordance with the JORC Code. A competent person has not done sufficient work to classify the historical estimate as a mineral resource ore reserve in accordance with the JORC Code. It is uncertain that following evaluation and/or further exploration work that the historical estimate will be able to be reported as a mineral resource ore reserve in accordance with the JORC Code.

The 1940 historical estimate data provides a good level of transparency with regard to the input data and the calculation methods used. The estimation resulting from the drill hole data was cross-checked by Mansfeld AG against the production grades at the Wolfsberg and Schnepfenbusch mines, which were operating in the area at the time of 1940 historical estimate. The comparison was favourable, and hence the assays from the exploration holes were used. GreenX has reviewed original records covering 17 of the 18 holes (~95%) used for the historical estimation and found no discrepancies.

Mansfeld AG made specific adjustments as part of the 1940 historical estimate to account for sterilisation. A total of 250,000 tonnes of contained copper was omitted to account for areas where surface features might prevent mining. Mansfeld AG also estimated that a further 23,793 tonnes of contained copper had already been extracted by mining at Wolfsberg and Schnepfenbusch (at a production grade of 2.2% Copper). This amount was then  subtracted from the historical estimate, as presented in the original source document (refer Table 1 above).

1984 ST JOE'S HISTORICAL ESTIMATE

Part of the Ronshausen zone of the 1940 historical estimate was drilled by St Joe Exploration during the 1980's, resulting in recognition of the St Joe's historical estimate more than 40 years later. Of the many holes drilled by St Joe, a total of 14 holes were used in the estimate of 169,000 of contained copper and 6.5 million ounces of contained silver. The St Joe's work estimated grades of 2.1 % copper and 25 g/t silver at typical depths between 290 and 370m (Figure 3).

St Joe benefited from both technological advancements and enhanced geological understanding in the 40 years following the work by Mansfeld AG. Consequently, St Joe assayed wider intersections and found that the mineralisation was up to 3.45m width. The historical estimate was calculated using thicknesses of between 1.5 to 2m, considerably thicker than the narrow Kupferschiefer assayed and estimated by Mansfeld AG in 1940.

Figure 3: Map showing the drill holes and locations of the Ronshausen zone of the 1940 historical estimate and the relative location of the 1984 St Joe's historical estimate

Given the increased mineralisation thickness covered by St Joe and the fact that the drilling covered only 28% of the Ronshausen zone, the St Joe's historical estimate further validates the 1940 historical estimate. The identification of much thicker mineralisation and contained silver also points to considerable exploration upside over all five mineralisation zones covered by the 1940 historical estimate.

Cautionary statement: The historical estimates in this announcement are not reported in accordance with the JORC Code. A competent person has not done sufficient work to classify the historical estimate as a mineral resource or ore reserve in accordance with the JORC Code. It is uncertain that following evaluation and/or further exploration work that the historical estimate will be able to be reported as a mineral resource or ore reserve in accordance with the JORC Code.

1930s DRILLING CAMPAIGN

The 18 holes used in the 1940 historical estimate were drilled between 1935 and 1938 (Figure 4). The southern holes tested the downdip continuation of known Kupferschiefer mining sites from the mid-1800s and led to the opening of the Wolfsberg and Schnepfenbusch mines. In the northern area, the drilling discovered previously unknown down-faulted Kupferschiefer that does not outcrop and had not been previously exploited. This discovery led to the opening of the Reichenberg mine. 

GreenX recently found the majority of the relevant original records of these drill holes in a regional archive. To date, of the 95 holes indicated to exist in the 1930s database, the Company has found logs for 43 holes, and of those, original historical assay results have been found for 35 holes. GreenX is continuing the archive search whilst digitising the records to add to the geological database for the Project.

Drilling up to 95 holes today is estimated to cost over €25 million and take several years, given modern permitting requirements. The discovery of the original historical drill database and 1940 historical estimate not only represents a significant saving in both time and money for GreenX, but it also provides valuable data points for its current exploration work program, including exploration targeting and 3D modelling. Combined with the 47 drill cores GreenX is currently re-logging and sampling (Figure 4), the quantity of previous exploration data available at Tannenberg is quickly growing, and underscores Tannenberg as a significant brownfield exploration opportunity.

Figure 4: Location Map of GreenX's Tannenberg project area showing the newly discovered 95 x 1930s drillholes, the location of the three underground copper/ silver mines opened during the late 1930s, and the location of the modern era 47 archive core holes that GreenX now has access to for re-logging and sampling

Upcoming Work Programs

The discovery of this historical estimate and the National Socialist era drill database is part of the Company's continued search for original historical mining and production data in German archives, which are part of a broader exploration program at Tannenberg, which includes: 

·      Logging, assaying, and hyperspectral scanning of historical core (ongoing);

·      Reprocessing and analysis of historical geophysical data (ongoing);

·      Collation of historical geological, mine development, and production data (ongoing); and

·      Airborne magnetic and radiometric survey (results released in September 2025)

In light of the discovery of this significant upgrade in the understanding of the Tannenberg mineralisation, GreenX is planning a future twin drilling campaign to verify the historical estimates, in order to establish a mineral resource estimate in accordance with the JORC Code.

ENQUIRIES

Competent Person Statement - HISTORICAL Estimate

The information in this announcement that relates to historical estimates is based on information reviewed and compiled by Dr Matt Jackson, a Competent Person who is a member of the Australian Institute of Mining and Metallurgy. Dr Jackson is a Technical Consultant for GreenX and is a holder of unlisted options in the Company. Dr Jackson has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'.  Dr Jackson consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears. Dr Jackson confirms that the information provided under ASX Listing Rules 5.12.2 to 5.12.7 is an accurate representation of the available data and studies relating to the Tannenberg Copper Project.

Forward Looking Statements

This release may include forward-looking statements, which may be identified by words such as "expects", "anticipates", "believes", "projects", "plans", and similar expressions. These forward-looking statements are based on GreenX's expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of GreenX, which could cause actual results to differ materially from such statements. There can be no assurance that forward-looking statements will prove to be correct. GreenX makes no undertaking to subsequently update or revise the forward-looking statements made in this release, to reflect the circumstances or events after the date of that release.

The information contained within this announcement is deemed to constitute inside information as stipulated under the Regulation 2014/596/EU which is part of domestic law pursuant to the Market Abuse (Amendment) (EU Exit) Regulations (SI 2019/310) ("UK MAR"). By the publication of this announcement via a Regulatory Information Service, this inside information (as defined in UK MAR) is now considered to be in the public domain.

REFERENCES

Mansfeldsche Kupferschieferbergbau AG. (1940). On the development of the Richelsdorf area. In German. State archive of Saxony Anhalt Region (Merseburg)*

St Joe Exploration GMBH. (1984) A Final report on the activities of St Joe Explorations GMBH in the Kupferschiefer project, Richelsdorf 1984. Archive No 17. PO BOX, 5780, 3000 Hannover 1.*

*English translation of the original source document

SCHEDULE 1 - HISTORICAL ESTIMATE

Details of Non-JORC Historical Estimates in relation to ASX Listing Rule Chapter 5

Listing Rules 5.10 to 5.12: Requirements applicable to reports of historical estimates of mineralisation for material mining projects:

JORC Code, 2012 Edition - Table 1 Report

Section 1 Sampling Techniques and Data

(Criteria in this section apply to all succeeding sections.)

Section 2 Reporting of Exploration Results

(Criteria in the preceding section also apply to this section.)

Section 3 Estimation and Reporting of Mineral Resources

Given the Company is reporting non-JORC historical estimates, further exploration and evaluation activities are required to be completed to verify the historical estimates as mineral resources in accordance the JORC Code. Accordingly, the Company cannot complete the Section 3 Estimation and Reporting of Mineral Resources JORC table until a mineral resource estimate can be verified and estimated. There is no certainty that further exploration work will result in the historical estimate being reported in accordance with the JORC Code.