NE Tasmania – A Continuation of Victorian Western Lachlan Fold Belt
Gold deposits in Northeast Tasmania lie within a continuation of the Western Lachlan Fold Belt in Victoria – one of the world’s largest orogenic gold provinces.
The Western Lachlan Fold Belt in Victoria hosts the >3 MOz Fosterville Mine, Bendigo and other Tier 1 goldfields and has produced >80 MOz gold.
NE Tasmania hosts the Beaconsfield Mine (2.3 MOz), New Golden Gate Mine (0.3 MOz) and Lefroy Goldfield (0.2MOz), along with hundreds of smaller historic gold mines and occurrences.
While Victoria is currently experiencing intense gold exploration activity, NE Tasmania has had very little modern gold exploration undertaken.
Stellar NE Tasmania Exploration Licences
Stellar’s wholly owned subsidiary, Tarcoola Iron Pty Ltd, holds 12 Exploration Licences in NE Tasmania covering a combined area of 2,212 km2 which is prospective for gold, tin, lithium and base metals.
Eleven of Stellar’s twelve EL’s (EL10/2020 to EL18/2020, EL2/2021 and EL3/2021) are prospective for Victorian style Orogenic Gold and for Intrusive Related Gold Systems (IRGS).
EL19/2020 (Scamander) and EL3/2022 North Scamander Block are highly prospective for tin and base metals with significant historic exploration and drilling undertaken over the licence areas.
EL3/2022 Mt Paris Block is prospective for Tin and Lithium.
There are ~77 recorded historic gold occurrences and ~83 tin and base metals occurrences over Stellar’s Exploration Licences in NE Tasmania.
NE Tasmania Priority Exploration Targets & Work Program
22 medium to very-high priority desktop exploration targets within Stellar’s Northeast Tasmania EL’s have been identified by Stellar’s technical team.
The majority of these priority targets are orogenic gold and IRGS gold targets, other than the Scamander advanced tin and base metals targets on EL19/2020 and the Mt Paris tin and lithium target on ELA3/2022.
A summary of Stellar’s Northeast Tasmania priority exploration targets and planned field work programs is shown below.
Progress to date in 2021 includes:
- Very encouraging anomalous gold results from soil sampling program at Leura and Back Creek (EL12/2020)
- Encouraging anomalous gold pathfinder results from initial sediment sampling program completed at Nabowla (EL11/2020)
Field reconnaissance is underway over priority targets on Stellar’s NE Tasmania EL’s which is being used for further prioritisation of targets. Stellar has a full time Exploration Geologist undertaking field exploration in NE Tasmania.
Stellar has a full time Exploration Geologist undertaking field exploration in NE Tasmania. Progress to date in 2021 includes:
- Encouraging results from soil sampling program at Leura and Back Creek (EL12/2020)
- Stream sediment sampling program materially completed in July ‘22. Results pending (EL11/2020)
Field Reconnaissance of other targets is now underway to prioritise further field work programs.
Leura and Back Creek Soil Geochemistry Results
The Back Creek Goldfield is located near Pipers River, approximately 45km north of Launceston and 9km east of the Lefroy goldfield in Northeast Tasmania. Gold was first discovered at Back Creek in 1869 and worked up until 1890, with most production from the alluvial leads. Historical reports put gold grades from the hard-rock Franklin Mine on an third-party Mining Lease adjacent to Stellar’s EL12/2020 in a range between approximately 9 – 20 g/t Au (Broadhurst, 1935).
The Leura prospect is located on Stellar’s 100%-owned EL12/2020, 3km southeast of the main Back Creek goldfield. Both alluvial and hard rock occurrences were worked historically at Leura, with hard-rock grades estimated to average 57 g/t Au (Montgomery, 1894).
The combination of the high-grade historic gold mining occurrences, similar structural style to the Lefroy and Beaconsfield gold deposits, and the lack of modern exploration, led to Stellar prioritising gold exploration of the Leura and Back Creek prospects on EL12/2020 as its first field exploration program completed in 2021.
A C-horizon soil survey comprising of 276 samples at Leura and 274 samples at Back Creek was completed within EL12/2020, with the assay results announced in July 2022.
Leura Soil Sampling Results
Soil samples over the historic Leura Goldfield returned very encouraging gold assay results ranging from 0.1 to 2.4 g/t Au over a 400m – 500m strike length, open in both directions with likely extensions under shallow cover (>5m). These strongly anomalous soil gold results confirm the location of the previously described Leura reefs (veins) and extend their strike lengths. The high-grade gold soil results from Leura, combined with the likely strike extensions make this a very attractive drill target.
Back Creek Goldfield Soil Sampling Results
Soil samples over the Lady Emily, Nevermind and Hidden Treasure Reef prospects in the historic Back Creek Goldfield within EL12/2020 returned anomalous gold results including:
- Lady Emily Reef – anomalous gold soil results ranging from 0.02 to 0.16 g/t Au over a ~200m strike length over the historic Lady Emily Mine.
- Nevermind Reefs – anomalous gold soil results ranging from 0.02 to 0.23 g/t Au over ~100m strike length over the northern reef and 0.02 to 0.05 g/t Au over ~50m strike length over the southern reef of the historic Nevermind Mine.
- Hidden Treasure Reef – anomalous gold soil results over a range of 0.02 to 0.05 g/t Au and a potential strike length of >100m also characterise the approximate location of the Hidden Treasure Reef on EL12/2020, although transported cover has obscured the results over this area.
Compared to Leura, the soil gold assay results at Back Creek within EL12/2020 are lower (maximum 0.23 g/t Au), however, the Back Creek soil gold results are still encouraging. The reported east-west trend is clearly reflected in the contoured gold results, which clearly map the distribution and possible strike extensions of the historically mapped reefs (veins), despite the patchy alluvial cover.
Nabowla Stream Sediment Sampling Program
During 2022 Q2, 187 stream sediment samples were taken over the Nabowla gold exploration target on EL11/2020.
Results from these preliminary stream sediment samples have returned low level anomalous gold and pathfinder elements over a broad area coinciding with a Northwest trending magnetic lineament as shown below. An infill sampling program of ~20 samples is planned to further refine the target area.
Nabowla Gold Exploration Target (EL11/2020) – Stream Sediment Sampling Results (A) Gold and (B) Arsenic (points and local catchment areas) overlain on Greyscale Airborne Magnetics with Infill Sampling area highlighted
Scamander EL19/2020
The Scamander district contains a large number of metallic mineral occurrences hosted within folded and faulted Ordovician Mathinna Group sedimentary rocks and is underlain by a strongly fractionated alkali granite. The metalliferous nature of the district, well defined metal zonation and location above the inferred alkali granite suggest that known mineralisation in this area is spatially and genetically associated with the emplacement of the fertile granite.
Significant historic exploration for tin and base metals has been undertaken on Stellar’s Scamander EL19/2020 including extensive soil sampling, stream sediment sampling and drilling defining areas of anomalous Sn, Zn, Cu, Ag and Pb mineralisation extending to the NW and SE of the Great Pyramid mine within adjacent RL2/2009 held by Tin One Resources Incorporated. The Great Pyramid Tin Mine operated between 1928 and 1936 with 336 tonnes of ore mined at an average recovered grade of 0.88% Sn, implying an average grade of 1.5% Sn. The remaining Great Pyramid deposit within adjacent RL2/2009 has a JORC resource of 5.2Mt @0.2% Sn at a 0.1% Sn cut-off, with an average drilling depth of 46m, demonstrating the potential in the district.
Significant W, Sn, Cu and Zn anomalies are defined by stream sediment geochemistry which define a regional scale NW-SE trending mineralised corridor which includes the Pinnacles and North Scamander tin-base metals projects on EL19/2020, extending to the NW and SE of the Great Pyramid mine.
North Scamander Sn-Base Metals Target (EL19/2020)
The North Scamander tin-base metals project is characterised by an outcropping mineralised gossan, that has generated strong surface stream sediment and soil tin geochemistry anomalies over the prospect and corresponds with a significant aeromagnetic anomaly. Rock chip samples from the prospect return grades of up to 1.07% Sn.
Drilling over the North Scamander target completed in 1981 includes 4 shallow percussion and 4 diamond drillholes to approximately 250m depth which intersected intervals of pyrrhotite-cemented hydrothermal breccia associated with intense magnetite alteration of the wall rocks and strongly anomalous Sn, Cu and Zn values. Previous results include:
- NSD2 – 138m @ 0.8% Zn (from 31m), including 1m 0.45% Sn, 6.2% Pb, 7.8% Zn, and 62 g/t Ag
- NSD1 – 13m 0.1% Sn, 0.2% Cu, 0.1% Pb, 0.8% Zn and 25 g/t Ag (from 163m)
Pinnacles Sn-Base Metals Target (EL19/2020)
The Pinnacles tin-base metals project is characterised by widespread outcropping sheeted quartz-cassiterite veins which are likely responsible for the strong surface stream sediment and soil tin geochemistry anomalies over the prospect and corresponds with a low intensity aeromagnetic anomaly. Limited rock chip samples are available over the prospect
Historic drilling over the Pinnacles target completed in 1983 includes 12 RC holes to a maximum depth of 120m targeting a large Sn soil anomaly, related to the sheeted quartz-cassiterite veins mapped at surface. Sn grades up to 0.4% over a length of 1.0m were reported in drillhole PPH1, with holes either side also returned anomalous Sn.
Magnetic Inversion Modelling & Drill Targets
Magnetic inversion modelling undertaken by Stellar’s geophysical consultant has shown that drilling at North Scamander was not deep enough to intersect the core of the magnetic feature which represents a high potential drilling target. Whilst the Pinnacles prospect is characterised by a more subtle magnetic feature, its strong surface geochemical anomalies, mapped sheeted quartz-cassiterite veins and historic drilling results combine to make the Pinnacles prospect another high potential drilling target. Stellar plans to undertake ground IP surveys to further refine the North Scamander and Pinnacles targets prior to finalising drill hole designs to test these prospects.
Tasmanian Government Co-funded Exploration Drilling Grants totalling $83,750 were awarded to Stellar’s wholly owned subsidiary, Tarcoola Iron Pty Ltd in August 2022 to drill North Scamander and Pinnacles targets on EL19/2020 in 2023.