The Special Mining Licence (SML) for the Ngualla Project will be held under a newly formed Tanzanian entity, Ngwala Mining Limited (NML), which will be owned 84% by Peak’s Tanzanian subsidiary, PR NG Minerals Limited (PR NG), and 16% by the GOT.
Summary:
Rare earth and barite mineralisation at Ngualla is magmatic in origin and hosted within the core of the Ngualla Carbonatite. Mineralisation has been residually enriched in the oxide zone at surface through weathering and the removal of carbonate minerals to variable depths of up to 140 m vertically.
High-grade rare earth mineralisation is hosted within the iron oxide and barite-rich weathered zone and above an irregular karstic surface, referred to as the Weathered Bastnaesite Zone. For modelling purposes, upper grade thresholds of 0.69% P2O5 and 13.99% CaO have been used to assist with the definition of Weathered Bastnaesite Zone Mineral Resource subset reported, which has been found through test work to be most amenable to the current metallurgical extraction process.
Rare earths are the main commodities of current economic interest within the project. Rare earths were first enriched in the carbonatite intrusions by igneous processes and further upgraded to economic or subeconomic levels by weathering processes and subsequent partial erosion. The major zones of mineralisation identified in the project area are:
• Southern Rare Earth Zone (SREZ), comprising the Bastnaesite Zone (hosted in fresh and weathered carbonatite) and Monazite Zone;
• Southwest Alluvials (SWA);
• Northern Zone (NZ).
The SREZ is a 1.0 km by 1.2 km area in the low magnetic central core of the Ngualla carbonatite complex. The SREZ itself is a geographic area that contains three different styles of rare earth mineralisation. Central to the SREZ is the Bastnaesite Zone, where rare earth mineralisation is hosted by primary ferroan dolomite at 1% TREO to 2% TREO and enriched to 3% TREO to 8% TREO in overlying in situ iron oxide and barite-rich residual weathered regolith. The Bastnaesite Zone is surrounded by the 200 m wide Monazite Zone.
The mineralisation is hosted within and upon a carbonatite pipe, with elevated REO concentrations occurring both within the carbonatite, and in the colluvial cover material. For resource modelling, a total of six separate estimation domains were defined in the SREZ and three domains in the SWA.
The SREZ covers an area of approximately 1.5 km2 , with the following lithologies variably distributed over these areas:
• Colluvium covers approximately 40% of the area, and has an average thickness of 8 m, but in places exceeds 60 m.
• Low calcium weathered carbonatite occurs in approximately 25% of the area, and has an average thickness of 36 m, and a maximum thickness of 150 m.
• High calcium weathered carbonatite occurs in approximately 25% of the area, and has an average thickness of 29 m, and a maximum thickness of 105 m.
• Fresh carbonatite has been intersected in approximately 85% of the area, with an average modelled thickness of 88 m, and a maximum modelled thickness of 215 m.
• Weathered ultramafic occurs in approximately 5% of the area, and has an average thickness of 35 m, with a maximum vertical interpreted thickness of 105 m.
• Fresh ultramafic occurs in approximately 5% of the area, and has an average modelled thickness of 70 m, with a maximum modelled vertical thickness of 165 m.
The SWA cover areas of approximately 2.3 km2 , with the following lithologies variably distributed over these areas:
• Colluvium covers approximately 50% of the area, and has an average thickness of 12 m, and a maximum thickness of 70 m.
• Weathered carbonatite was intersected in approximately 30% of the area, with an average intersected thickness or 9 m and a maximum of 65 m.
• Fresh carbonatite was interpreted under the full extent of the SWA, but not included in the reported resources.