Rare Earth Elements Uncovered in South Australia’s Bonython Critical Mineral Corridor
Recent research has shed new light on the mineral potential of South Australia’s Curnamona Province, with the identification of previously unrecognised monazite and xenotime minerals within the Bonython Critical Mineral Corridor (BCMC). These highly sought-after minerals are known to host valuable rare earth elements (REEs) and were discovered in samples exhibiting Radium Hill-type mineralisation. This finding is particularly significant as these specific minerals have not previously been associated with this style of mineralisation in the region.
The research is a collaborative effort between Heavy Rare Earths (HRE) and academics at Adelaide University, as part of the Australian Research Council’s Centre for Critical Resources for the Future (CCRF). This project aims to delve into the mineralogical origins and geological settings of REEs, scandium, yttrium, and uranium within the Radium Hill area. It forms part of a broader CCRF initiative focused on exploring the critical mineral potential of the entire Curnamona Province.
HRE Chairman Gabriel Chiappini expressed his encouragement regarding the research outcomes. “We are encouraged with the results of research and studies performed thus far at Adelaide University as part of the Australian Research Council (ARC) Centre for Critical Resources for the Future (CCRF),” he stated. “It has been a pleasure to collaborate with such respected scholars and researchers. Our collaboration has uncovered key indicators of the existence of sought-after heavy rare earths elements and yttrium, with the presence of monazite and xenotime in mineral systems congruent with that of the Radium Hill mine.”
Chiappini further highlighted the strategic importance of these discoveries. “These studies continue to add to the strategy of unlocking the multi-commodity critical minerals at our Radium Hill project,” he added. “There has been limited research into Radium Hill-style mineralisation for over 60 years, with previous historical work focused almost exclusively on Uranium.”
The Bonython Critical Mineral Corridor: A New Perspective
The Bonython Critical Mineral Corridor (BCMC) is an 8-kilometre structural zone trending northeast, stretching from the historic Radium Hill mine – Australia’s inaugural uranium mine – to Bonython Hill. Historically, exploration along this corridor has concentrated almost entirely on uranium. Small-scale mining operations, including pits and shafts, are dotted across the BCMC, marking prospects and historical drilling targets such as Railways, Bristowe’s, Radium Hill North, and Bonython Hill.
Crucially, past exploration efforts focused on uranium hosted within dravite in shear zones at the main Radium Hill mine. These investigations did not extend to understanding the distribution of REEs, scandium, and yttrium, either in proximity to uranium orebodies or within any other rock types along the BCMC.
Under the current research collaboration, initial analyses have been conducted on two samples. The first originated from ore stockpiles at the historical Radium Hill Mine, located at the southern extremity of the BCMC. The second sample was sourced from Taylor’s Shaft, a pre-World War II uranium mine situated at the northern end of the corridor.
Further samples have been collected from various points along the zone situated between the Radium Hill Mine and Taylor’s Shaft. These samples are currently undergoing processing.
Promising Preliminary Findings
Preliminary findings from this limited testing have revealed the presence of valuable accessory minerals, including monazite and xenotime. These minerals are found in association with the already well-documented davidite-rutile-ilmenite mineralisation.
Monazite and xenotime are highly prized for their role as sources of critical REEs. Importantly, established and proven processing flowsheet technologies exist for their commercial production, making these discoveries particularly promising for future development.
The identification of these REE-bearing minerals in conjunction with Radium Hill-style mineralisation marks a significant shift in understanding the geological potential of the BCMC. It opens up new avenues for exploration and highlights the possibility of a multi-commodity critical mineral endowment within HRE’s landholdings. The ongoing research aims to further delineate the extent and grade of these newly identified REE resources, potentially transforming the economic outlook for the region.
The historical focus on uranium alone may have overlooked substantial opportunities for critical mineral extraction. This new research is poised to rectify that oversight and unlock a broader spectrum of valuable resources.
