Pensana Rare Earths Plc (LSE: PRE, ASX: PM8) announced that high-grade rare earths in soils were confirmed from the first sampling programmes completed at its Coola Project in Angola.
The company said that the assay results received from soil sampling over the Coola carbonatite identified a high tenor soil anomaly up to 4.69% REO extending over a 1.3 x 1.4 kilometre area.
PM8 said that the highest REO values lie over the 3.2 kilometre perimeter of the carbonatite ring structure and are coincident with an outcropping circular carbonatite dyke. The company noted that the centre of the 1.2 kilometre diameter ring structure is anomalous in REO in soils despite lying beneath thick soil cover, which could partially mask a soil response.
The company reported that an area of outcropping fluorspar mineralisation located 300 metres south of the ring structure is also associated with anomalous soils to 2% REO. Pensana said that it plans to drill test these defined targets in 2021.
The 7,500 square kilometre Coola Project lies just 16 kilometres north of the Company’s Longonjo rare earth development project.
Pensana had identified several carbonatite and alkaline complexes within Coola with geological prospectivity for critical technology metal commodities that could complement future NdPr rare earth production from Longonjo.
Two carbonatite complexes, Coola and Monte Verde, were confirmed as mineralised through academic work identifying NdPr rare earth mineralisation in rock samples.
The Coola and Monte Verde carbonatites
The Coola and Monte Verde carbonatites, like Longonjo, are intrusive or volcanic ring structures containing carbonatite rock and are known to be enriched in elements and minerals associated with rare earth mineralisation such as fluorite, strontium, barite, phosphorous and niobium. They are also the same Cretaceous age (135 million years) age as Longonjo and part of the same regional geological event.
The Coola Carbonatite forms part of a larger 6 kilometre x 2.5 kilometre multi‐centre volcanic system and associated fenite alteration. Previous academic work had identified rare earth enrichment to 3.64% REO from limited rock sampling (Alberti et al., 1999).
Sampling programmes at Coola project
The company had completed systematic soil sampling and geological mapping programmes over two geological targets in October. PM8 announced that the assay results from the Coola Carbonatite have now been received.
High-grade assays from Coola
Pensana said that high-grade rare earths in soils were uncovered from the first sampling programmes at Coola project. PM8 said that the results from the soil sampling programme show a high tenor rare earth in soils anomaly extends over a wide area.
PM8 announced that soils contain up to 4.69% REO over an outcropping carbonatite ring dyke system that forms part of the 1.2 kilometre diameter Coola Carbonatite.
The central part of this circular volcanic structure lies entirely beneath thick soil cover. Several 3 metre deep pits were excavated in the central area but failed to reach bedrock, so the potential for additional prospective carbonatite and the mineralisation potential remains unknown. PM8 said that the assay results from vertical channel samples of the pits are awaited.
PM8 said that outcropping fluorspar mineralisation was located within the Coola complex during the geological mapping. As well as being listed as a critical commodity and having direct economic potential in its own right, fluorspar is also a positive indicator of the potential for additional technology metals in this geological setting. Pensana said that the assay results from rock samples of fluorspar mineralisation are awaited.
New exploration manager
PM8 announced that accomplished economic geologist Grant Haywood has been appointed as its new Exploration Manager. Grant was involved with the evaluation of carbonatites in South Africa, Malawi, Namibia, Mozambique, Uganda, Zimbabwe, and Tanzania as well as in a range of other commodities and geological styles including platinum, gold, base metals, graphite, and industrial minerals.
Site activities at Longonjo
PM8 reported that on site at the Company’s flag ship Longonjo NdPr Project just to the south, a large diameter drilling programme was successfully completed.
The company said that the drilling, using a large diameter drill rig, was successful in quickly and efficiently obtaining over 170 tonnes of mineralisation from surface to 24 metres depth. The drilling was completed to provide feed for the further optimisation and pilot plant programmes for the Company’s expanded strategy of mining and processing operations in Angola and a UK refinery.
A total of 15 drill holes were completed using a specialized large diameter drill rig to provide representative bulk samples of weathered zone mineralisation from surface to 24 metres depth.
The company expressed confidence that 100 tonnes of mineralisation from the areas of proposed first mining will provide feed for the further optimisation and pilot plant programmes of the expanded processing operations in Angola and the UK.
The company announced that an additional soil sampling programme has been completed over the Monte Verde alkali – carbonatite complex and assay results are expected shortly. PM8 said that it plans to drill test the Coola rare earth anomalies and report the outstanding assay results from the Monte Verde soil sampling as they are received.
Pensana said that the geological mapping and sampling of the large, twin centre Sulima alkali complex is planned for early 2021. The company said that stream sediment sampling programme and geological reconnaissance of a series of geophysical anomalies has commenced and will continue.
The Company said that it expects to report the Wood Group study of the Angolan based mine and processing plant and establishment of a UK rare earth refinery in January 2021.
PM8 said that further work includes wide spaced soil sampling at Sulima; regional stream sediment sampling and geological reconnaissance over the wider region of the licence area; geological mapping and rock sampling to accompany the regional sampling; trenching and drilling programmes to test priority targets once assay data from the above programmes is received; and drilling at Coola to test the high tenor soil anomalies, outcropping fluorspar mineralisation and soil covered c entre of the Coola Carbonatite.
Pensana’s Chief Operating Officer Dave Hammond said: “These high-grade rare earth assays are a great start, from what is only the first of several exploration targets for critical technology metals identified within the new Coola Project.
Results confirm a rare earth mineralised carbonatite at Coola that is now sufficiently well‐defined for drill testing. Drilling will also determine if rare earth mineralised carbonatite lies beneath the soil cover in the central part of the one kilometre diameter volcanic pipe.
It is great to have Grant join us and lead the team going forward with his extensive experience in the evaluation of rare earth deposits and a whole range of other commodities.
Assay results from soil sampling at the Monte Verde carbonatite – alkali complex are expected shortly and sampling of the Sulima Complex target will commence early next year.
The drilling programme at Longonjo was efficiently and successfully executed under Grant’s supervision and 100 tonnes of the mineralisation is now on its way to Perth.”