27 January 2022

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR"), and is disclosed in accordance with the Company's obligations under Article 17 of MAR

Thor Mining PLC

Ragged Range Project, WA

Lithium targets and exploration program

The directors of Thor Mining Plc ("Thor") (AIM, ASX: THR, OTCQB: THORF) are pleased to provide an exploration update on the lithium prospectivity at the Company's 100% owned Ragged Range Project, located in the Eastern Pilbara, Western Australia.

Project highlights:

§ Several lithium exploration targets have been identified at Thor's Ragged Range Project.

§ The Pilbara Craton is highly prospective for lithium-caesium-tantalum (LCT) enriched pegmatites and hosts two "World Class" deposits at Wodgina and Pilgangoora that formed close to the Split Rock Supersuite (2.85 to 2.83Ma).

§ Prospective LCT ground adjacent to the Split Rock Supersuite (2.85 to 2.83Ma) is identified in three areas covering the northern portion of Thor's tenure.

§ The lithium potential on the Ragged Range Project area has not been previously considered.

§ E46/1393 tenement located in the northeast over the Kelly copper-gold workings has now been granted (Figure 1), with this structurally complex region favourable for lithium enriched pegmatites.

§ With E46/1393 granted, Thor plans to complete airborne magnetics and radiometrics over the north-eastern portion of the tenement package, with detailed geological mapping, pXRF analysis and rock chip sampling over the lithium targets, to determine pegmatite mineralogy and identify any lithium-caesium-tantalum minerals.

Nicole Galloway Warland, Managing Director of Thor Mining, commented:

"Thor's recent geological review of the Ragged Range project, triggered by the granting of E46/1393, has identified exciting lithium-caesium-tantalum targets associated with the highly prospective Split Rock Supersuite. These new targets will be advanced as soon as possible and have the potential for significant exploration discoveries, while we continue drill testing further gold exploration targets at the Sterling Prospect. 

The Pilbara Craton already hosts two "world class"  lithium deposits, and ground with battery metals prospectivity at our 100% owned Ragged Range project is an exciting new development, and has the potential to create substantial value for Thor shareholders."

The Ragged Range Project, located in the prospective Eastern Pilbara Craton, Western Australia, is 100% owned by Thor Mining - covering E46/1190, E46/1262, E46/1355, E46/1340 and recently granted E46/1393 (Figure 1).

Figure 1: Tenement Location Plan overlying GSWA 1:500k geology showing distribution of Split Rock Supersuite with priority lithium target areas (Red dash ovals) may be viewed by the following link:

https://www.thormining.com/sites/thormining/media/pdf/ASX-Announcements/20202021/rr_tenure-and-li-prospective-areas.jpg

Regional Pilbara Lithium Prospectivity

The Pilbara Craton is highly prospective for lithium-caesium-tantalum enriched (LCT) pegmatites and hosts two large and globally significant spodumene deposits at Wodgina (Mineral Resources Ltd) and Pilgangoora (Pilbara Minerals).  The Wodgina lithium project is considered the largest hard rock, spodumene deposit in the world (https://www.carbonart.com.au).

The lithium rich pegmatites in the Pilbara are spatially, and appear to be genetically, related to the Split Rock Supersuite (2.85 to 2.83Ma), which are post-tectonic (Sweetapple, M, 2017). These are mapped as highly fractionated, biotite, quartz and K Feldspar rich, monzogranites (Figure 2).

Pegmatites are located within 10 km of cogenetic peraluminous granites and leucogranites. The roof zones of large plutons are considered to be one of the most favourable positions for lithium enrichment  (London, 2018). An idealized concentric pegmatite swarm is shown in Figure 3, showing the spatial zonation of pegmatites around a common granitic source, which is a fundamental starting point for exploration models (London, 2018). Using this as a model, the Ragged Range area fits all these conditions.

Commercial lithium is found in the mineral spodumene LiAl(Si₂O₆), that can grow into very large crystals within pegmatite bodies. It is normally associated with minerals such as cassiterite (Sn), columbite-tantalite (Nb-Ta), lepidolite (lithium rich mica), beryl (Be) and garnets. These elements  can be used as pathfinders in stream sediment sampling programs.

Ragged Range Lithium Potential Targets

At the southern end of the Corunna Downs Batholith (Figure 2), crescent shaped post-tectonic granitic pluton is found (now termed the Mondana Monzogranite part of the Split Rock Supersuite).  The Mondana Monzogranite is porphyritic and is largely unfoliated. Small units of the Mondana Monzogranite are mapped in the NE corner of E46/1262, E46/1340 and E46/1393 and three target areas have been defined ( Figure 1):

1)    This NE corner of E46/1262 is potentially a roof zone of the Mondana Monzogranite, making it the most prospective area for lithium in the tenements (Figure 1 and 4).

2)    The second target area is on E46/1393 where numerous structures cut the older Euro Basalt providing conduits for pegmatites emanating from the adjacent Mondana Monzogranite.

3)    The third area of interest is a small enclave of greenstone at the contact of the Mondana Monzogranite in E46/1340.

There is negligible sampling to date along the Mondana Monozogranite contact, with a few samples taken as part Thor's 2019 and 2020 stream sediment sampling programs (THR:AIM announcement 1/12/2020).  No assays are available for Li however elevated Sn, Be, Nb and Ta routinely assayed, warrant  further investigation.

Figure 2: Geological map of the units and terranes comprising the North Pilbara Craton (adapted from Sweetapple and Collins, 2002 and Hickman, 2016), highlighting the distribution of the Split Rock Supersuite (~2.85-2.83 Ga) and pegmatite fields and groups of LCT (Li-Cs-Ta), NYF (Nb-Y>F) and mixed (LCT-NYF) petrogenetic families of Cerny and Ercit (2005). Ragged Range tenure is shown covering the southern portion of the Split Rock Supersuite and Corunna Downs Batholith (after Sweetapple., 2017).

https://www.thormining.com/sites/thormining/media/pdf/ASX-Announcements/20202021/split-rock-supersuite.jpg

Figure 3: Idealised concentric, regional zoning pattern in a pegmatite swarm from USGS 2010 publication (not to scale). Characteristic rare-element suites of the most enriched pegmatites in each zone are indicated.  The most enriched pegmatites tend to occur distally with respect to the parental granite.

https://www.thormining.com/sites/thormining/media/pdf/asx-announcements/20202021/idealised-pegmatite-swarm.jpg

In the Thor aeromagnetic data, radiometrics, (the uranium channel is shown on Figure 4) thorium and uranium are moderately anomalous over mapped small bodies of unknown derivation in the NE corner of E46/1262, confirming the presence of pegmatites or monzogranite within the low response signal of the Euro Basalt. Interestingly, the prominent dyke that runs NNE/SSW across this area is both magnetic and has a moderate uranium and thorium response. It is therefore unlikely that this dyke is a simple dolerite body, as currently mapped. 

Figure 4: Uranium channel radiometrics overlain on 1:100K Geology (GSWA) highlighting potential pegmatites and lithium targets in the north-easern corner of E46/1262 may be viewed via the following link:

https://www.thormining.com/sites/thormining/media/pdf/asx-announcements/20202021/radiometrics-in-ne-e46-1262.jpg

Next Steps

In parallel to the gold exploration activities at the Sterling Prospect, the following lithium work program is planned:

1)      Airborne magnetic/radiometric survey to be flown over the eastern portion of the tenure including E46/1340 and E46/1393.

2)      A detailed review of all available high-resolution imagery and aster data, to see if the presence of pegmatites can be visually detected.

3)      Reconnaissance stream sediment sampling and prospecting along the contact of the Mondana Monzogranite (E46/1262, E46/1190, E461393 and E46/1340), with detailed sampling (Figure 1),

a.    in the higher ranked ground in the northern corner of E46/1262

b.    the structurally more complex area of E46/1393

c.     the small slice of greenstone within the Mondana Monzogranite on E46/1340,

4)      Investigation of all small granitic and pegmatitic bodies in the target area. Lithium is detectable on XRF and will fluoresce in UV light. Positive samples can then be assayed for lithium and key pathfinder elements including Ce, Rb, Sn, Ta and W.

References

Bagas L, Van Kranendonk J and Pawley M: 2004, Geology of the Split Rock 1:100000 Sheet, GSWA.

Bradley D C, McCauley A D, and Stillings L M: 2010, Mineral-Deposit Model for Lithium-Cesium-Tantalum Pegmatites. USGS.

London D: 2018, Ore forming processes within granitic pegmatites, Ore Geology Reviews 101.

Sweetapple M T: 2017, A review of the setting and internal characteristics of lithium pegmatite systems of the Archaean North Pilbara and Yilgarn Craton. GSWA.

Sweetapple MT and Collins P L F: 2002, Genetic Framework for the Classification and Distribution of Archean Rare Metal Pegmatites in the North Pilbara Craton, Western Australia. Economic Geology Vol 87.

This announcement is authorised for release to the market by the Board of Directors.

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For further information on the Company, please visit www.thormining.com or contact the following: