Diatreme Unveils Massive 115-275 Mt Silica Expansion at Casuarina
Diatreme Resources has outlined two substantial exploration targets near its Northern Silica Project, potentially adding up to 275 million tonnes of high-purity silica sand adjacent to the world-class Cape Flattery mine.
- Casuarina East and West targets defined via LiDAR and remote sensing
- Combined exploration target tonnage between 115 and 275 million tonnes
- Targets lie adjacent to Mitsubishi’s Cape Flattery Silica Mines
- No field sampling or drilling completed yet; planned within 12 months
- Northern Silica Project holds Major Project status, critical for solar PV supply
Strategic Expansion Adjacent to a Global Silica Giant
Diatreme Resources Ltd (ASX, DRX) has taken a significant step forward in expanding its Northern Silica Project (NSP) in Far North Queensland by defining two new conceptual exploration targets; Casuarina East and Casuarina West. These targets, identified through advanced LiDAR terrain modelling and geomorphological analysis, suggest a combined potential silica sand resource ranging from 115 million to 275 million tonnes.
Located immediately adjacent to the Cape Flattery Silica Mines, operated by Mitsubishi and renowned as one of the world’s largest and highest purity silica sand producers, the Casuarina targets represent a promising extension of this globally significant dune system. Diatreme’s CEO, Neil McIntyre, emphasised the strategic importance of this proximity, noting the compelling scale and geometry of the deposits despite their early-stage status.
Exploration Targets Based on Remote Sensing, Awaiting Ground Truthing
Importantly, these exploration targets are conceptual and derived entirely from remote data sources; high-resolution airborne LiDAR and satellite imagery; without any physical sampling or drilling to date. The volumetric models estimate dune thickness and volume by interpreting surface topography and interpolating the base of the silica sand horizon, using a conservative bulk density assumption of 1.65 tonnes per cubic metre.
Diatreme plans to initiate a staged drilling program within the next 12 months to validate these models, confirm sand quality, and refine resource estimates. This step is critical to move from conceptual targets to defined mineral resources compliant with the JORC Code.
Infrastructure and Environmental Considerations
In July 2025, Diatreme’s board and management conducted a site visit to assess the NSP mining and marine loading infrastructure, noting the proximity of Cape Flattery Port, which currently operates below its daytime capacity of 6 million tonnes per annum. The company is actively engaging with Queensland Government authorities and local stakeholders to ensure port access arrangements maximize existing infrastructure use while minimizing environmental and cultural impacts.
McIntyre highlighted the company’s commitment to responsible development, emphasizing the importance of respecting Traditional Owners and community concerns, and advocating for the full utilization of current port capacity before considering new construction.
Northern Silica Project’s Growing Significance
The NSP has recently been designated a Major Project by the federal government, underscoring its strategic value as a critical minerals source, particularly for the solar photovoltaic industry which demands high-purity, low-iron silica sand. Diatreme’s global silica sand resource base, including the NSP and adjacent projects, now exceeds 500 million tonnes, positioning the company as a key player in supplying materials essential for global decarbonization efforts.
Partnering with global materials group Sibelco, which holds a minority stake and has invested substantially in the project, Diatreme is advancing towards a Pre-Feasibility Study that will further define the economic potential of the NSP.
Bottom Line?
As Diatreme moves from remote sensing to drilling, the market will watch closely for confirmation of these vast new silica resources and their impact on the company’s growth trajectory.
Questions in the middle?
- Will drilling confirm the high purity and continuity of the Casuarina silica sands?
- How will environmental and cultural approvals influence the project timeline?
- What are the implications for Diatreme’s market position if these targets convert to resources?
