STAVELY PROJECT

The Stavely Project is located in western Victoria on the Stavely tablelands approximately 250 km to the west of Melbourne. The Project comprises exploration licence 4556, over which a retention licence (RL2017) has been applied for, and the Black Range Joint Venture exploration licence 5425.

In October 2018, The Company was awarded the right to apply for Block 3 (EL6870) in the Victorian Government’s Stavely Ground Release Tender. EL6870 is still going through the application process. 

At the Thursday’s Gossan Prospect, a near surface secondary chalcocite-enriched blanket has an estimated Mineral Resource of (using a 0.2% Cu grade lower cut-off) –28Mt at 0.4% copper for 110kt of contained copper (gold and silver not estimated).

The Company is targeting a Cadia-style gold-copper porphyry and Lake Cowal-style gold mineralisation in the Stavely Project.

REGIONAL GEOLOGY

The Stavely Project is hosted in Cambrian age fault-bounded belts of submarine calc-alkaline volcanics, namely the Mount Stavely Volcanics, structurally in contact with the older quartz-rich turbidite sequence of the Glenthompson Sandstone and the Williams Road Serpentinite. 


These sequences were deformed in the Late Cambrian Delamerian Orogeny. Seismic traverses and a recent study by the Victorian Department of Economic Development, Jobs, Transport and Resources in western Victoria have supported the interpretation of an Andean-style convergent margin environment for the development of the buried Stavely Arc beneath the Stavely Volcanic Complex and environs. This regional architecture is considered conducive to the formation of fertile copper / gold mineralised porphyry systems as is the case with the Macquarie Arc in New South Wales, which hosts the Cadia Valley and North Parkes copper-gold mineralised porphyry complexes.

The Lachlan Fold Belt and Delamerian sequences are in fault contact through large-scale thrusting along the east dipping Moyston Fault.

Largely unconformably overlying both these domains by low-angle décollement is a structural outlier of the younger Silurian fluvial to shallow marine sandstone to mudstone sequences of the Grampians Group.

THURSDAY'S GOSSAN COPPER-GOLD PORPHYRY PROSPECT

 

Stavely Minerals is making significant advances in its search for a well-mineralised copper-gold porphyry at Thursday’s Gossan. 
All the indications are that the system is a very hydrous, strongly oxidised and well-endowed with metals, and displays both multi-phase intrusion and mineralisation events as well as ‘telescoping’ of later mineralisation over earlier events – all attributes for a well-mineralised copper-gold porphyry system.  Evidence of copper-gold alkalic porphyry mineralisation includes:

  • Porphyry M Veins

M vein with intergrown chalcopyrite in SMD024 –

  • 70m at 0.22% Cu,  including

    • 3m at 1.01% Cu, 0.16 g/t Au and 8 g/t Ag

  • High-grade copper-gold mineralised late D veins

Bornite – chalcopyrite D vein in SMD015 –

  • 9m at 2.62% Cu & 0.28 g/t Au, including

    • 4m at 5.41% Cu & 0.35 g/t Au

  • 4m at 5.85% Cu & 0.27 g/t Au, including

    • 1m at 10.75% Cu & 0.60 g/t Au

  • Broad intervals of low-grade copper-gold wall rock mineralisation – equivalent in tenor to pre-discovery drill intercepts at Cadia-Ridgeway.

Recently completed diamond hole SMD044 intersected the largest intervals to date:

  • 952m at 0.23% Cu from 11m

        Other broad low-grade wall rock mineralisation intercepts include:

  • 314m at 0.11% Cu in SMD029W1

  • 124m at 0.31% Cu & 0.12 g/t Au in SMD012

  • 85m at 0.35% Cu & 0.18 g/t Au in STRC005D

  • Multi-phase intrusion and mineralisation events

Anhydrite stockwork veining with well-developed

chalcopyrite in SMD044

Late bornite-chalcocite cutting earlier pyrite dominant

porphyry D veins in SMD044

  • Copper -Lode Splay with high-grade copper-gold-silver

Pyrite-chalcopyrite-bornite-covellite-chalcocite vein in SMD032 –

  • 6m at 6.73% Cu, 0.84 g/t Au & 15 g/t Ag, including

    • 1m at 22.8% Cu, 0.91 g/t Au & 48 g/t Ag

  • 2m at 2.43% Cu, 0.28 g/t Au & 4.9 g/t Ag

 

Copper – Lode splay in SMD044 returned -

  • 70m at 0.51% Cu from 580m, including:

    • 41m at 0.78% Cu, including:

      • 10m at 2.43% Cu, 0.30g/t Au and 11g/t Ag, including:

        • 1m at 8.97% Cu, 1.13g/t Au and 36g/t Ag

  • Aplite dykes, A Veins, light isotopic values less than -33‰ ɗ34 sulphur

Recently completed diamond hole SMD044 intersected the largest intervals to date:

  • 952m at 0.23% Cu from 11m

 

Including from the Copper Lode Splay (CLS):

  • 70m at 0.51% Cu from 580m, including

    • ​10m at 2.43% Cu, 0.30g/t Au & 11 g/t Ag

  • ​  

Including from the North-South Structure (NSS)

  • 38.3m at 1.59% Cu, 0.27g/t Au & 8g/t Ag from 890m, including

    • ​12.3m at 2.59% Cu, 0.44g/t Au & 18g/t Ag

These structurally-controlled zones of high-grade copper-gold-silver mineralisation are now recognised as copper lode-style mineralisation similar to that at the Magma Mine in Arizona, USA which are closely associated with the Resolution porphyry copper deposit (Inferred Resource of 1.8Bt at 1.53% copper – RTZ, 2018). 


The causative porphyry intrusion, which should contain the hottest and best-developed mineralisation has not yet been seen.

 
The convergence of the NSS and the CLS to the south of SMD044 is considered an ideal focus for the porphyry intrusion, as noted in other porphyry districts, and will be targeted by the next drill hole.

 
Dr Greg Corbett, a respected porphyry expert, has inspected the drill core at Thursday’s Gossan on several occasions.  His reports are available on the Technical Data page.

World Bank Copper Price, US$/t (June 2016)

 

 

The conceptual study identified a number of opportunities to enhance project economics including:

  • Increasing the size of the resource –recent drilling has identified chalcocite copper mineralisation outside the current Mineral Resource. Stavely Minerals’ drill hole SMD004 intersected 52m at 0.23% copper from 39m downhole depth. This intercept is located approximately 400m to the west of the existing Mineral Resource and illustrates the potential for material increases;

  • Reducing the assumed mining and milling costs by investigating the suitability of using continuous surface mining equipment. The attraction of the mining method is that it is well suited to long and wide, flat-lying, mineralisation; the oxidised nature of the mineralisation is well suited to this mining method; the product is already partially comminuted and reduces the need for primary crushing; and this mining method can be very selective in the vertical dimension.

  • Reducing the processing costs through lowering reagent usage and by streamlining the processing flowsheet – the Scoping Study will investigate the potential to beneficiate the mineralised from un-mineralised clays prior to flotation of the sulphide concentrate amongst other processing enhancements.

 

Recent RC/ diamond drilling at Thursday’s Gossan has returned shallow copper-gold (and silver) intercepts which are very significant for the potential development of the near-surface chalcocite enriched ‘blanket’.   All previous Mineral Resource estimates for the Thursday’s Gossan chalcocite have only estimated the copper within the deposit, excluding gold and silver. This was mainly because previous explorers had not assayed for gold or silver in many drill holes within this zone. Recent results conclusively demonstrate that significant gold and silver grades are hosted within the Mineral Resource area.

Thursday’s Gossan Resource – Conceptual Study

The Company’s conceptual study on the potential for copper concentrate production from the chalcocite-enriched supergene ‘blanket’ at the Thursday’s Gossan copper deposit demonstrated sufficient positive outcomes with respect to net revenue and Net Present Value, as well as an attractive Internal Rate of Return, to proceed to a scoping study.

There are as not yet reasonable grounds to support the discussion of these projected economic outcomes in detail.

The key elements of the conceptual study include:

  • An average feed grade of 0.5% copper;

  • A sulphide flotation recovery of 87% (based on metallurgical testwork); and

  • A sulphide concentrate grade of 27% copper (based on metallurgical testwork) producing a very ‘clean’ concentrate with low deleterious elements.

 

Financial assumptions included:

  • World Bank forecast copper prices;

  • A range of A$/ US$ exchange rates of A$1 = US$0.60 to US$0.75

Mount Stavely Copper-Gold Porphyry Prospect

 

The exploration target at Mount Stavely is porphyry related copper-gold mineralisation associated with the Mount Stavely Volcanic Complex (MSVC) in the Mount Stavely Belt.

The Mt Stavely porphyry target is reflected as a ‘low’ in gravity data and as a ‘low’ in the airborne magnetic data which is interpreted to reflect magnetite destructive hydrothermal fluid alteration. A porphyry is inferred to exist at depth and is in proximity to marginal gold mineralisation at the Fairview gold prospect, which itself is interpreted to be a low-sulphidation epithermal style mineralisation. An IP survey in the Mt Stavely area returned a chargeability feature which was slightly offset from the gravity low. Geochemical soil sampling over the Mount Stavely prospect returned anomalous arsenic, molybdenum and gold values.

While the diamond hole drilled in 2017 at Mount Stavely did not encounter any mineralisation or porphyry alteration signatures in the drill core, a pebble dyke characterised by rounded milled clasts in a pyrite altered rock flour matrix has been identified. Pebble dykes are commonly used to vector towards porphyry mineralisation and its’ presence is considered to be extremely encouraging that there is a copper-gold porphyry in the Mount Stavely area.

The two diamond holes drilled in 2018/2019 at the Mount Stavely porphyry prospect, intersected porphyry zones, minor copper mineralisation and low temperature epithermal quartz veins and sulphides in separate drill holes.
 

Fairview Gold Prospect

 

The 4.8 kilometre long Fairview North and Fairview South mesothermal to epithermal gold anomalies was originally identified in soil sampling and followed-up with shallow reconnaissance aircore, RC and limited diamond drilling. The previous drilling returned numerous anomalous gold intercepts, including:

  • 5 metres at 17.44 g/t gold from 28 metres drill depth to end of hole,

  • 2 metres at 16.06 g/t gold from 23 metres drill depth,

  • 4 metres at 6.69 g/t gold from 10 metres drill depth,

  • 17 metres at 1.70 g/t gold including 5 metres at 3.1 g/t gold from 12 metres drill depth,

  • 12 metres at 2.16 g/t gold from 18 metres drill depth to end of hole including 3 metres at 5.1 g/t gold from 27 metres drill depth to end of hole.

 

The Fairview gold anomaly is associated with sericite albite and K-spar (adularia) alteration and quartz sulphide veins with chalcopyrite, sphalerite, galena and gold. The sphalerite is of a pale yellow colour and in conjunction with the adularia suggest a low-temperature possibly low-sulphidation epithermal affinity. The target at Fairview is a Lake Cowal-style gold deposit. 

Previous drilling failed to provide a focus for further drilling and the IP programme conducted in late 2016 was also not successful in identifying any definitive drill targets.  

Following a new interpretation of the structural controls for gold mineralisation at the prospect by Stavely Minerals a single diamond hole was drilled at Fairview North in early 2017. The hole returned an encouraging intercept of:

  • 30 metres at 1.4 g/t gold including

    • 11 metres at 2.4 g/t gold 

 

Follow-up drilling in mid -2017, comprising four RC drill holes around this previous intercept, has returned good widths of moderate grade gold mineralisation within large widths of low-grade gold mineralisation including:

  • 17 metres at 1.23 g/t gold from 23 metres drill depth within a larger low-grade interval of

    • 57 metres at 0.57 g/t gold from surface

  • 16 metres at 1.04 g/t gold from 6 metres drill depth within a larger low-grade interval of

    • 68 metres at 0.42 g/t gold from surface.

 

Additional intercepts included:

  • 6 metres at 1.65 g/t gold from 53 metres drill depth;

  • 4 metres at 1.70 g/t gold from 5 metres drill depth; and

  • 1 metre at 6.70 g/t gold from 76 metres drill depth.

 

Independently, Geoscience Australia drilled a diamond hole (STAVELY-17) in the immediate vicinity of the Fairview South prospect in 2014 as part of a series of holes drilled in the Stavely region as pre-competitive stratigraphic drilling. 

A geochemical study of the pyrites recovered from STAVELY-17 was released in 2017 and concluded that there was two-stage pyrite growth – a high temperature early stage which was likely to be related to porphyry-style mineralisation at depth and a low-temperature later stage which is likely an epithermal overprint.

This was compared by Geoscience Australia to the pyrite in the Wafi-Golpu and Lihir porphyry / epithermal copper-gold and gold deposits.  Jeff Steadman and Ross Large (ARC Centre of Excellence in Ore Deposits, University of Tasmania) went on to conclude that the estimated distance to the target porphyry would be 0.5 - 1 km.

Black Range Joint Venture Project

 

Drill hole SMD027 was drilled in 2018 to a depth of 251.3m to test a discrete magnetic feature along a major north-south structure, approximately 2 km north of the Thursday’s Gossan copper-gold porphyry prospect.  The presence of disseminated magnetite, seen throughout the gabbro explains the magnetic anomaly. 


From the litho-geochemistry, the intrusion in SMD027 which was logged as a ‘monzogabbro’ plots in the subalkaline to alkaline gabbro field.  The intrusive from SMD027 plots within the barren intrusive field within the Bob Loucks’ Cu+Au productivity plot.   An age date from a combination of U/Pb ratios on individual spots in apatite and titanite grains from the gabbro was 478±21Ma. While the error is large it clearly shows the gabbro to be of Cambrian age and contemporaneous with the mineralisation at the Thursday’s Gossan porphyry prospect, and not a Devonian intrusion.

  
A review of the exploration potential of the Black Range Joint Venture with Navarre Minerals Limited has identified the Lexington prospect in the Bucheran Diorite to be worthy of follow-up soil sampling and drilling. At Lexington the copper-gold mineralisation appears to be fracture controlled and possibly postdates the emplacement of the intrusion. Another area of interest includes several magnetic lows, interpreted by the Geological Survey of Victoria to be a Cambrian intrusion, in the northern part of EL5425, at the junction between the Elliott and Stavely belts. 

 

Latest News

Shallow Copper-Gold Discovery Continues to Grow with New High-Grade Intercepts in Step-Out Drilling

Individual 1m grades of up to 8.42% Cu and 8.69g/t gold returned in SMD053, located 320m south-east of the discovery hole SMD050, as drilling program gathers momentum

Stavely Announces $19.6M Capital Raising to Sophisticated and Institutional Investors

Proceeds to underpin and expedite gold and copper-gold exploration in western Victoria, Tasmania and Queensland

Outstanding Thick Intercepts in First Step-Out Hole Confirm Substantial Shallow Copper-Gold Discovery

Grades of up to 19.3% Cu in SMD051, 160m south of the discovery hole, within two wide zones up to 59m down-hole at the Ultramafic Contact Fault 

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