The Lake Johnston Project is located 240km from the port of Esperance in the Southern Goldfields region of Western Australia. It covers +50 km strike of the Lake Johnston Greenstone Belt, which consolidates the southern region for the first time.
Burmeister Lithium Deposit
The Lake Johnston Greenstone Belt hosts defined Lithium-caesium-tantalum (LCT) pegmatites – a source of about one-fourth of the world’s lithium production and most of the tantalum production. TG Metals has discovered the Burmeister Lithium Deposit, a series of stacked shallow dipping spodumene bearing pegmatites (refer to figure below). The pegmatites are “blind” under cover with no outcrop and were discovered by drilling beneath prominent lithium soil anomalies. TG Metals completed a series of Reverse Circulation (RC) and Diamond Drilling (DD) programs in late 2023 and early 2024 to be able to calculate an initial resource and Exploration Target based on Direct Shipping Ore (DSO) metrics.
A maiden Resource and updated Exploration Target Statement was announced on the 18th August 2026 (ASX Release) of:
| Class | Li2O Cutoff | Tonnes | Li2O | Rb | Ta | Fe | MgO |
| % | Millions | % | ppm | ppm | % | % | |
| Inferred | 0.40 | 6.71 | 1.18 | 3,668 | 104 | 1.32 | 1.02 |
Table 1 – Burmeister Resource August 2026
Notes:
- MRE is reported above a Li2O cut-off grade of 0.40% within an optimised pit shell using appropriate mining and processing costs, recoveries, concentrate payabilities and revenue values
- Mineral Resources are not Mineral Reserves – further detailed economic studies and additional modifying factors are required
- The MRE was classified following the guidelines presented in JORC Code 2012
- Totals may not add up due to rounding
Exploration Target Statement
The Company has also updated the Exploration Target estimate (Table 2) for the Burmeister Lithium deposit within the Lake Johnston Project, Western Australia. The Exploration Target is in addition to the Resource defined in Table 1, composed of the pegmatite domains that are not classified as Inferred and have been estimated with the available drill hole data.
| Tonnes Range
Low |
Tonnes Range High | Li2O Range
Low (%) |
Li2O Range
High (%) |
| 11 million | 14.5 million | 0.90 | 1.20 |
Table 2 – Exploration Target Range at 0.4% Li2O cutoff
The Exploration Target quantity and grade is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource. The Exploration Target is based on the Company’s resource definition drilling undertaken since discovery in October 2023. The current drill hole density for some areas within the drill defined Burmeister deposit are not considered sufficient to determine a Mineral Resource.
To address the issue of Reasonable Prospects for Eventual Economic Extraction (RPEEE), the Burmeister Mineral Resource has been constrained by an optimised pit shell.
Initial flotation testwork on the fines material, combined with HLS testwork, shows overall lithium recovery of 75.5% to 80.2% to produce quality spodumene concentrates low in impurities. Combined concentrate grades range from 5.28% to 5.74% Li2O, complimenting previous testwork with HLS/DMS-only concentrate grades of up to 6.31% Li2O.
An initial assumption was made that ore could be processed and shipped as DSO (Direct Shipping Ore) using a price of US$ 400/tonne. Following good results from metallurgical testwork, an alternate assumption producing a 6% spodumene concentrate with a price of US$ 2,000/tonne was also tested. The two optimisations used Inferred material only and produced almost identical results.
The Burmeister Inferred Mineral Resource Estimate has been constrained by the optimal pit shell and reported at a 0.40% Li2O cutoff.
The figures below show the conceptual DSO pit shell around the initial Resource and the Exploration Target modelled mineralisation.
Jaegermeister Lithium Prospect
The prospect has significant potential for definition of a lithium Resource with significant lithium drill intercepts. Jaegermeister is located to the north east of the Burmeister deposit, figure below and presents a future expansion of the Lake Johnston lithium project.
Bremer Range Ni Co Laterite Deposits
The majority of the historical drilling is shallow – testing only the oxide material. Multiple drill results of +1% nickel and cobalt up to 6,900 ppm defines large nickel-cobalt oxide (surficial/lateritic) deposits. Any “Exploration Target” for nickel-cobalt oxide deposits stated by past operators is not compliant with the JORC Code.
TG Metals completed a desktop study on past drilling focusing on the potential of nickel laterite deposits at Bremer Range and were able to define an Exploration Target based on historical drilling data (ASX Release on the 10 November 2022) of:
| Exploration Target Cutoff Grades |
Tonnes Range Low |
Tonnes Range High |
Ni Range (Low %) |
Ni Range (High %) |
Co Range (Low %) |
Co Range (High %) |
| 0.3% Ni | 28 million | 32 million | 0.41 | 0.47 | 0.029 | 0.034 |
| 0.5% Ni | 7 million | 8 million | 0.55 | 0.65 | 0.045 | 0.053 |
Exploration Target Ranges at 0.3% and 0.5% Ni cutoffs
The potential quantity and grade of the Exploration Target is conceptual in nature. It is based on historical drilling data which is of variable quality and deficient in some analysis for deleterious element and compositing of samples (up to 4m) is not conducive to determining a Mineral Resource of sufficient accuracy. Past drilling did however, define 5 zones of nickel laterite mineralisation. These zones were modelled within defined grade enveloped and aggregated to determine the total Exploration Target ranges in the table above.
Mineralisation envelopes were interpreted in section from drill data. A nominal 0.2-0.3% Ni edge lower cut off was initially developed and adjusted as required to capture and delineate the majority of significant and related Copper (Cu), Cobalt (Co), Chrome (Cr) and Zinc (Zn) mineralisation. The development of wire-frames were tightly controlled and typically not extended (extrapolated) beyond one average section spacing from the last drillhole ‘point of observation’. The 5 main mineralisation areas defined and modelled are outlined in the figure below (Area 2 and Area 4 are not labelled however defined by the yellow outline). In addition, 3 typical or example sections to illustrate the nature of the Bremer Range Ni-Co laterite mineralisation.
Exploration Strategy
Despite a long history of exploration in the Lake Johnston Belt, surficial cover and deep weathering have made discovery a challenge. TG Metals is overcoming these challenges through modern geophysical and geochemical techniques. Already the new geochemistry via lithium soil sampling has been successful in discovering blind lithium pegmatites at the Burmeister discovery. In addition, TG Metals is investigated seismic as a means to depict subsurface geological boundaries. LIDAR (Light Detection and Ranging) has also been effective in defining topographical features which show previously unseen subsurface structures. TG Metals has a staged approach to mineral exploration which focusses in on mineral occurrences and deploys drilling in a targeted cost-effective manner.
TG Metals intends to continue it’s staged, targeted approach, employing modern techniques to capitalise on mineral targets which have not been being fully tested or completely missed in past exploration.
Development Strategy
TG Metals immediate focus is on progressing the development of the Burmeister DSO potential. To this end, the Company has applied for a Mining Lease over the entire Burmeister deposit and water exploration licence over known ground water drill hits to the south. Haulage routes to Esperance port and discussions with potential offtakers are well advanced.
