New Sirmac Pegmatite Yields Lithium Grades Up to 3.0% Li2O with Significant Cesium

Discovery Highlights

Winsome Resources (ASX: WR1) has revealed a promising new high-grade spodumene-bearing pegmatite at its Sirmac-Clapier Project in Quebec, Canada. The outcrop, measuring approximately 100 metres north-south by 60 metres east-west, was identified during the company’s recent field season exploration efforts. Channel sampling has confirmed lithium grades reaching up to 3.0% Li2O, accompanied by significant cesium and tantalum mineralization.

This discovery is particularly notable given the scarcity of cesium globally, with only a handful of deposits mined historically. Winsome’s assays detected cesium levels exceeding laboratory detection limits in some samples, prompting re-analysis to precisely quantify this valuable element.

Strategic Location and Infrastructure

The Sirmac-Clapier Project lies roughly 30 kilometres from existing provincial road infrastructure and about 100 kilometres north of regional centres Chibougamau and Chapais, which connect to rail networks. This proximity to transport infrastructure is a strategic advantage for potential development. Additionally, the project is situated approximately 600 kilometres by road from the Renard Operation processing facilities, over which Winsome holds an option, potentially streamlining future processing pathways.

Exploration and Future Work

Winsome’s exploration team employed systematic geological and geophysical data reviews to prioritize targets across its Quebec portfolio, with Sirmac-Clapier being a relatively underexplored area due to prior focus on the flagship Adina Lithium Project. The initial discovery was followed by detailed channel sampling using diamond saw cuts to minimize sampling bias, with multiple crosscuts confirming consistent high-grade mineralization.

Looking ahead, Winsome plans to undertake further mapping and drill testing throughout 2025 to better define the extent and orientation of the pegmatite body. The company is also collaborating with Power Metals Corp, leveraging their expertise in cesium mineralization, as Winsome holds a significant equity stake and offtake rights in Power Metals’ Case Lake Project.

Market and Strategic Implications

Managing Director Chris Evans highlighted the excitement around new discoveries, emphasizing the potential to expand Winsome’s lithium portfolio beyond Adina. The addition of high-grade cesium and tantalum mineralization could diversify the company’s product offerings and enhance project economics, especially given the limited global supply of cesium.

While the discovery is still at an early stage, the combination of high-grade lithium and critical minerals in a well-located project area positions Winsome to capitalize on growing demand for battery and technology metals. The upcoming exploration results and assay updates will be closely watched by investors and analysts alike.