Medcalf Lithium Deposit Boasts 8.2Mt @ 1.0% Li2O in Maiden Resource Estimate

A Milestone for Lake Johnston

Charger Metals NL has delivered a significant milestone with the announcement of a maiden inferred mineral resource estimate for its Medcalf Lithium Deposit, part of the broader Lake Johnston Lithium Project in Western Australia. The estimate stands at 8.2 million tonnes grading 1.0% lithium oxide (Li2O) at a 0.5% cut-off grade, marking a promising start for the company’s systematic exploration efforts in this Tier 1 jurisdiction.

Expanding the Lithium Footprint

Alongside the maiden resource, Charger Metals has defined an exploration target at the adjacent Medcalf West Prospect, estimated between 3 and 5 million tonnes with grades ranging from 1.0% to 1.4% Li2O. Although still conceptual and requiring further drilling to confirm, this target highlights the substantial upside potential within the Lake Johnston project area. Both Medcalf and Medcalf West remain open at depth, suggesting that the resource base could expand significantly with ongoing exploration.

Strategic Partnership with Rio Tinto

Rio Tinto Exploration Pty Limited continues to play a pivotal role by sole funding exploration activities under a farm-in agreement with Charger Metals. For 2025, Rio Tinto has budgeted $1.1 million and up to 5,000 metres of drilling to test additional lithium targets within the project. This partnership not only provides financial backing but also validates the prospectivity of Lake Johnston in the eyes of a major global mining player.

Geological and Technical Insights

The Medcalf deposit is hosted within spodumene-bearing pegmatites, a lithium mineralisation style well-regarded for its near-surface accessibility and high-grade potential. The resource estimate was independently completed by Ashmore Advisory Pty Ltd in accordance with the 2012 JORC Code, ensuring industry-standard rigour and transparency. The deposit is considered amenable to open pit mining, with ongoing metallurgical testwork aimed at confirming processing parameters for lithium concentrate production.

Positioning in a Competitive Landscape

Lake Johnston’s location in the Yilgarn Province places it near other significant lithium projects, including the Earl Grey (Mt Holland) Lithium Project operated by Covalent Lithium and Core Lithium’s Finniss Lithium Mine in the Northern Territory. Charger’s progress at Medcalf, combined with Rio Tinto’s involvement, positions the company well to capitalize on growing demand for battery metals critical to electric vehicles and renewable energy technologies.