Lithium bearing pegmatites identified at Trident Project NSW

KEY POINTS:

• Numerous lithium bearing pegmatites have been visually identified at TSC’s 100% owned Trident Project in NSW
• Multiple rock chip samples show visual amblygonite (Li,Na) AlPO₄ (F,OH) and lepidolite K(Li,Al)₃(Al,Si,Rb)₄O10(F,OH)₂ ¹
• Current rock chip sampling program will complement historical geochemical sampling results that include the following samples ^2&3:
  • Triumph Mine: 63% Li2O
  • Lady Don Mine: 45% Li2O
  • Trident Mine: 88% Li2O
  • Sceptre Mine: 56% Li2O
  • Esams No.2 Mine: 05% Li2O
• TSC has also undertaken a review and small sampling program of several historical copper workings around the central and southern portion of the Trident licence area
• Assays from initial rock chip sampling programs are expected in 4 to 6 weeks

 

Commenting on the initial observations from the Trident sampling program, CEO Simon Phillips said:

 

“We are pleased with the initial observations from our first round of sampling at Trident, which so far validates encouraging historical results and supports our belief that Trident has very clear potential to host lithium-bearing pegmatites. In addition to the presence of lithium and tin, our team has also reported evidence of copper mineralisation in the form of malachite and azurite which is very encouraging.

The Trident Project remains significantly underexplored and continues to shape as an exciting opportunity for TSC, and we look forward to providing regular updates on exploration progress over the coming months.”

 

Twenty Seven Co. Limited (ASX: TSC) (“TSC” or “the Company”) is pleased to announce that it has completed a first pass rock chip sampling program at the Trident Project in NSW.  A total of 152 rock chip samples have been taken (see figure 2) from across the Northern portion of the tenement.

The program was completed over the most prospective anomalies within the Trident Project area, with potential lithium, caesium and tantalum, with niobium, and tin pegmatites visually identified by TSC’s field crew.

All samples have been dispatched to a laboratory in South Australia for full assay suite analysis, with first assays expected to be received in November / early December.

 

Trident Sampling Program Background

 

As recently reported (see ASX release dated 16 September 2021), TSC’s technical team has compiled extensive amounts of historical geochemical data regarding the Trident Project area from the NSW MinView geological database, which has led to the identification of multiple new lithium and tin targets.

The lithium, tin, caesium, and tantalum (LCT) pegmatites identified have been sampled by previous explorers and show that lithium occurs within amblygonite, and lesser lepidolite which are both important minerals for lithium mining.  Historically, sporadic tin mining occurred in the Euriowie Tin Field from the 1880’s to 1970’s, leaving the area littered with evidence of old workings.

Initial visual results have been particularly encouraging and have identified the presence of pegmatites with evidence of lithium and tin bearing minerals (amblygonite and lepidolite) as well as the presence of tin (cassiterite).  Numerous samples have also been taken which show the evidence of copper mineralisation in the form of malachite and azurite.

 

Figure 1: Location of TSC’s Broken Hill tenements

 

Figure 2: Map showing the locations of the recently taken rock chip samples.

 

Figure 3: LHS shows quartz rich portion of a pegmatite showing very coarse grained cassiterite (555380mE and 6531663mN).

 

Figure 4: LHS showing potential massive amblygonite at Badjerrigarn (556724mE and 6525624mN)

 

Figure 5: Copper rock sample from 556952mE 6515319mN

 

Figure 6: Queen Victoria mine workings potentially mined for tin (556487mE and 6526498mN looking south)

 

LCT Mineralisation Model

 

Felsic pegmatites are igneous intrusive bodies of granitic composition with extremely coarse grainsize.  LCT pegmatites are a subset of granitic pegmatites that consist mostly of quartz, potassium feldspar, albite, and muscovite.  LCT pegmatites host the significant Greenbushes lithium deposit in Western Australia, (133.1Mt @ 2.1% Li₂O)⁴ as well as other numerous significant lithium deposits.

Within the Curnamona Province in the Broken Hill Block, pegmatites are largely conformable to stratigraphy and have similarities to sill complexes (Fitzherbert, 2015). Pegmatites within the region are hosted within Paleoproterozoic and Mesoproterozoic units with each effecting the composition and mineralisation type. The oldest rocks within the Thackaringa and Broken Hill Groups are metamorphosed to higher grade granulite and upper amphibolite facies and younger rocks within the Sundown and Paragon Groups are metamorphosed to lower amphibolite to greenschist facies (Figure 7).

Figure 7:  Pegmatite schematic model for the Broken Hill region showing sill development within different metamorphic facies present within the Euriowie tenure [EL8736] (Silver City Mining)⁵

 

Importantly, a recent study into the lithogeochemistry of pegmatites in the region highlighted that pegmatites hosted within lower amphibolite and greenschist facies of the Sundown and Paragon Groups contain tin, tungsten, lithium, niobium and tantalum, while pegmatites within higher grade metamorphic rocks host elevated lead-zinc-silver-manganese (Coianiz, 2018)⁶. The bulk of the LCT pegmatites in the Project area occur within the Paragon Group. The pegmatites can be divided into two prospectivity groups as shown below:

1. Pegmatites hosted in lower amphibolite and greenschist facies of the Sundown and Paragon Groups are referred to the ‘upper sill complex’ (includes LCT – Waukeroo Type pegmatites); and
2. Pegmatites (and leucogranite) within the granulite and upper amphibolite facies of the Thackaringa and Broken Hill Groups can be described as a ‘lower sill complex’ as they form bodies which are largely strata bound (Figure 8).

Figure 8: A conceptualisation of the Pegmatites in the Broken Hill Region showing sill development within the local stratigraphy of the Trident Project (After Stevens 2006) ^7&8

 

Figure 9: Location of pegmatite occurrences and lithium targets within Trident

 

Next Steps

 

TSCs intended next steps over the coming months include the following:

• Receive Trident assay results from the laboratory and plan future work,
• Visit the Perseus tenement once mustering allows access,
• Commence drilling key anomalies at the Rover Project in WA; and
• Commence geochemical sampling along the Edale shear at Rover.

 

References

1. Visual identification of amblygonite is problematic therefore field identification my not correspond to laboratory assays.
2. Dukovic, T. (2017) Annual Report for EL8468 for the Period 22 September 2016 to September 2017. Unpublished Report Mica Exploration Areas Pty Ltd, GSNSW Report GS2018_0298_RE0010150_ALL.EL8468 Annual Exploration Report 2017.
3. Refer to ASX announcement dated 16^th September 2021: Lithium and Tin Targets Identified at Trident Project, NSW
4. BDA Independent Technical Report for Greenbushes Lithium Operation, March 2020; Mineral Resources are inclusive of Ore Reserves. The estimate has not been depleted for mining after 31 March 2018.
5. Silver City Minerals – Proactive investor presentations (5-6 July 2016)
6. Coianiz, Glenn & Torrey, Chris. (2018). Lithogeochemistry of Pegmatites at Broken Hill: An Exploration Vector to Mineralisation. ASEG Extended Abstracts. 2018. 1. 10.1071/ASEG2018abM1_2D.
7. Stevens, B.P.J. & Burton, G.R. (1998). The early to late Proterozoic Broken Hill Province, New South Wales. 17. 75-86
8. Nile Exploration – Information memorandum: Overview of Lithium potential of the Trident Project in NSW (EL8736) unpublished report