Chilwa Minerals has verified rare earth elements in its first diamond drill hole at the Mposa anomaly within Malawi’s Chilwa Carbonatite system, marking a significant milestone in its critical minerals exploration program.
- Maiden diamond drilling at Mposa reveals elevated TREO values up to 1,039 ppm
- Monazite confirmed as a key rare earth element-bearing mineral
- Initial 6-hole drilling campaign at Mposa completed with breccia identified
- Drilling advanced to second target, Mpyupyu, showing carbonatite alteration and sulphide mineralisation
- Program targets 47 geophysical anomalies with further assay results pending
Exploration Breakthrough at Mposa
Chilwa Minerals Limited (ASX, CHW) has announced a pivotal development in its rare earth elements (REE) exploration at the Lake Chilwa Basin in southern Malawi. The company’s maiden diamond drill hole at the Mposa geophysical anomaly has returned assay results confirming elevated total rare earth oxide (TREO) values reaching up to 1,039 parts per million (ppm) within clay, sediments, and saprolite layers extending to depths of 80 metres.
This discovery is particularly significant as it validates the presence of monazite, a rare earth-bearing mineral also found in the adjacent heavy mineral sands deposits, reinforcing the geological model that Chilwa is pursuing. The initial drilling campaign at Mposa, comprising six holes, has now been completed, with breccia, a rock type associated with explosive magmatic activity, identified in hole MPODD004 at depths between 188 and 190 metres.
Advancing to New Targets with Promising Signs
Following the Mposa results, Chilwa has progressed drilling to the second target, Mpyupyu, located approximately two kilometres from its mineral sands deposits. Early drilling at Mpyupyu has revealed fenitisation (potassic alteration), brecciation, and pervasive sulphide mineralisation including pyrite and chalcopyrite. These features are indicative of a carbonatite-related hydrothermal system, a geological setting known to host REE mineralisation.
The company is undertaking a systematic exploration program targeting 47 geophysical anomalies identified through airborne radiometric and magnetic surveys conducted in 2024. These anomalies exhibit thorium, potassium, and magnetic signatures consistent with carbonatite intrusions. Ground verification through mapping, soil geochemistry, and rock-chip sampling has guided the drilling campaign, with further assay results from remaining targets expected in the coming weeks.
Strategic Importance of REE Findings
Geochemical analyses confirm that the mineralisation is dominated by light rare earth elements (LREE) such as lanthanum, cerium, and neodymium, which are typical of carbonatite-hosted REE systems worldwide. Importantly, the presence of heavy rare earth elements (HREE) like dysprosium, erbium, and yttrium has also been detected at consistent levels. These HREEs are critical for emerging clean energy technologies and advanced electronics, underscoring the strategic value of Chilwa’s discoveries.
Chilwa’s Managing Director, Cadell Buss, highlighted the significance of these results, noting the company’s confidence in having identified a substantial critical minerals asset. He emphasized the establishment of a robust exploration drilling process and the clear pathway ahead to prioritize and test the remaining anomalies.
Looking Ahead
The exploration license covering the Chilwa project area was recently renewed, securing tenure for continued work over the next three years. Chilwa plans to expand its drilling capacity by deploying a second diamond drill rig to accelerate testing of high-priority targets. While the current drilling is at an early reconnaissance stage with no mineral resource yet defined, the comprehensive assay data and geological insights provide a strong foundation for future resource development.
As Chilwa advances its program, the relationship between the heavy mineral sands deposits and the newly identified REE mineralisation will be further clarified, potentially unlocking synergies in extraction and processing. The company’s methodical approach and promising early results position it well within the competitive landscape of critical minerals exploration in Africa.
Bottom Line?
Chilwa Minerals’ maiden drilling success at Mposa sets the stage for a potentially transformative rare earth discovery in Malawi’s emerging critical minerals sector.
Questions in the middle?
- How will upcoming assay results from the remaining 45 anomalies influence Chilwa’s exploration priorities?
- What are the potential economic implications of the LREE and HREE balance found in the Chilwa Carbonatite system?
- Could Chilwa’s mineral sands and REE deposits be developed synergistically to enhance project viability?