American Rare Earths reports expansion potential at Halleck Creek in Wyoming

American Rare Earths (ASX: ARR) reported on Wednesday surface sampling results across the Bluegrass, northern Overton Mountain and Sommers Flat areas that highlighted the expansion potential of its flagship rare earths project in Wyoming.

American Rare Earths’ subsidiary, Wyoming Rare, holds the Halleck Creek project, which was named by Mining Intelligence last year as one of the world’s top 10 rare earth projects measured in total rare earth oxides (TREO). The unit recently rejected a $400 million SPAC takeover offer.

The state has become an exploration hotbed for rare earths to reduce China’s grip on the market. The United States has only one producing rare earths mine, Mountain Pass in California, owned by MP Materials (NYSE: MP).

Based on a mineral resource estimate updated in February, Halleck Creek holds 2.34 billion tonnes grading 3,196 parts per million (ppm) TREO, including neodymium and praseodymium oxides, for 7.48 million tonnes of contained TREO. This includes 1.42 billion tonnes in the measured and indicated category.

ARR geologists collected 88 surface samples in June 2024 across previously unmapped or sparsely mapped expansion areas at Halleck Creek. ALS Global assayed the samples, which contained TREO values up to 5,280 ppm.

Most of the surface samples at Overton Mountain and Bluegrass show TREO values exceeding 2,770 ppm, with four samples exceeding 4,000 ppm TREO, the highest being 4,815 ppm. The mapped geology in this area consists almost exclusively of clinopyroxene quartz monzonite (CQM), which is the chief rare earth bearing rock type within the Red Mountain Pluton.

Reconnaissance scale mapping and sampling were also performed across the Sommers Flat resource area. The primary rock type here, biotite hornblende syenite (BHS), have lower TREO grades than the CQM. Thin dikes of higher-grade CQM cross-cut the BHS rocks at Sommers Flat, with two CQM dike samples returning TREO values of 4,726 ppm and 5,250 ppm.

The company said the results continue to demonstrate upside potential of the Halleck Creek district, and chief technical officer Dwight Kinnes said mapping and sampling show that Bluegrass will be a high-priority exploration and expansion area.

“This area is contiguous to prior drilling at the Overton area, and we plan to perform expanded exploration at Bluegrass and will be updating exploration permits with the Bureau of Land Management and Wyoming Department of Environmental Quality for 2024-2025,” Kinnes said in a news release.

“Additional field mapping and sampling at Sommers Flat will provide details on the CQM dikes and help us to determine if long-range exploration of Sommers Flat is warranted.”