Lake Johnston Lithium Project

Drill-ready lithium targets at Medcalf identified, and the approval process is advancing.

The Lake Johnston Project covers parts of the Archaean-aged Lake Johnston Greenstone Belt where LCT pegmatite swarms have been mapped and sampled along a 50km long corridor.

Figure 1: Lake Johnston Lithium Project Location approximately 450km east of Perth and 70km east of the Earl Grey Lithium Project (Covalent Lithium Pty Ltd).

The Medcalf Spodumene Prospect

The most advanced is the Medcalf Spodumene[1] Prospect, which is being prepared for drilling in the March quarter of 2023.  Here, a spodumene pegmatite cluster has been mapped indicating that it is least 500m long within a 300m-wide corridor.  Assays of spodumene-bearing pegmatite samples range between 1.51% and 5.13% Li2O.

The Medcalf Prospect was discovered by reconnaissance fieldwork in 2018 and 2019[2], when geologists visited a pegmatite shown on the GSWA[3] 1:250,000 Lake Johnston geological map.

Strongly anomalous soil geochemistry results and with further mapping completed, the Medcalf Prospect is now ready for drilling, and the Company is working through the precursor statutory DMIRS[4] and DBCA[5] requirements.

Figure 2: Medcalf Lithium Prospect showing mapped pegmatites, soil sample and rock chip locations. Assays shown are of spodumene-bearing rock chips. The central black rectangle aligns with the geochemical image in Figure 2 below. The large width of the outcropping pegmatite cluster will be drill tested.

[1] Spodumene is the preferred mineral for commercial lithium chemical production for the lithium battery industry.
[2] ASX: LIT 11 April 2019: Spodumene pegmatite swarm discovered at Lithium Australia’s Medcalf Prospect Lake Johnston, WA.
[3] Geological Survey of Western Australia
[4] DMIRS means Department of Mining, Industry Regulation and Safety.
[5] DBCA means Department of Biodiversity, Conservation and Attractions

The Mount Day Lithium Prospect

Numerous LCT pegmatites have been mapped at the Mount Day Prospect.  Soil geochemistry has been undertaken along a sample grid of 400m x 50m, prioritising areas for further work.

Mapping and further sampling will continue to establish the prospectivity of this area for spodumene.

Figure 3: Mt Day Prospect, showing named and mapped pegmatites, with Li2O and Ta analyses from rock chips, overlaying an image of lithium index values.

Location and Infrastructure

The Lake Johnston Lithium Project is located 450km east of Perth, WA.  Ownership is predominately 70% Charger and 30% Lithium Australia Limited.

The region hosting the Lake Johnston Project has attracted considerable interest in LCT pegmatite mineralisation due to its proximity to the large Mount Holland Lithium Project under development by Covalent Lithium Pty Ltd (a joint venture between subsidiaries of Sociedad Química y Minera de Chile S.A. and Wesfarmers Limited) located approximately 70 km west of the Lake Johnston Project.  Mt Holland is understood to be one of the largest undeveloped hard-rock lithium projects in Australia with Ore Reserves for the Earl Grey Deposit estimated at 94.2 Mt at 1.5% Li2O[6].

[6] Kidman Resources ASX Announcement dated 18 December 2018.

Field photos of the Medcalf spodumene pegmatites

Photo 1:  Spodumene pegmatite outcrop at Metcalf  (Photo Peter Spitalny)
Photo 2:  Raman spectroscopy used to confirm the presence of (crescumulate) spodumene at Metcalf.
(Photo Neil Scholtz)