Tyranna Resources (ASX:TYX) has completed a review of historical exploration data at the Coola Rare Earths & Niobium Project in Angola, identifying rare earth and niobium soil anomalies that define drill-ready targets around a 3km carbonatite ring dyke.
From about 1,084 historical soil samples, 185 assayed above 1.5% total rare earth oxides (TREO), including 26 above 5% TREO with a peak of 13.18%. A further 25 samples returned above 2% niobium oxide (Nb2O5), peaking at 3.9%.
Managing Director David Crook says the historical work has given Tyranna a refined suite of targets from the outset.
“More than a thousand soil samples define rare earths and niobium anomalies around the 3km Coola carbonatite ring, with grades up to 13% TREO and 3.9% niobium oxide at surface, supported by rock geochemistry,” Crook adds.
Rock chip sampling supports the soil geochemistry, with assays up to 4.85% TREO and 2.85% Nb2O5. Of 79 rock chip samples analysed, 11 assayed between 2.12% and 4.85% TREO, and 10 between 1.03% and 2.85% Nb2O5.
Coola is one of four alkaline intrusions identified on the 830km2 project. The carbonatite ring dyke has mapped exposures up to 50m wide in places and contains rare earth-bearing minerals including bastnäsite.
Of 49 auger holes drilled on a 100m by 100m grid within the central diatreme, eight returned values between 1.04% and 1.92% TREO.
The project sits within Angola’s Lucapa Graben, a tectonic corridor hosting alkaline intrusions including kimberlites and carbonatites.
Angolan carbonatites are considered analogues of Brazil’s deposits, which host major niobium, rare earth, and phosphate resources.
Crook says two mines are under construction nearby: Pensana’s (LSE:PRE) Longonjo Project, 45km south of Coola; and the Niobonga Niobium Project, 250km southwest.
Tyranna plans to collect 500 soil geochemistry samples from the wider Sulima West and Mt Verde prospects during the December quarter, alongside analysis of samples previously screened by portable X-ray fluorescence.
The company will continue historic data integration ahead of drilling at Coola in Q2 2027, subject to the wet season, which typically runs from November to March.
Tyranna Resources is an Australian explorer advancing battery and critical minerals projects across West Africa.
Write to JC Villarba at Mining.com.au
Images: Tyranna Resources
