Stavely Minerals reports best-ever intercept of 48m @ 1.39% Cu and 6.33g/t Au at Cayley Lode

by Leena Thomas
Image: Stavely Minerals Limited

Stavely Minerals Limited (ASX: SVY) announced that the ongoing resource drilling at the high-grade Cayley Lode discovery at the Thursday’s Gossan prospect within its Stavely Copper-Gold Project in Victoria has returned one of the most significant intercepts to date.

The company reported that broad zone of significant copper and high-grade gold mineralisation was intersected from shallow depths in the Cayley Lode including 48m at 1.39% Cu, 6.33g/t Au and 12g/t Ag from 85m down-hole, including 16.7m at 3.13% Cu, 17.93g/t Au and 29g/t Ag from 115m, including 2m at 0.74% Cu, 132g/t Au and 38g/t Ag from 116m.

SVY said that these spectacular new shallow intercepts come on the heels of an exceptionally wide intercept from drill hole SMD104 which included 144 meters at 1.04 per cent copper, 0.15 grams per tonne of gold, and 3.4 grams per tonne of silver from 35 metres.

The company said that the current focus of ongoing drilling is continuing to extend the shallow Cayley Lode mineralisation to the north-west.

SVY said that the significantly higher gold grades encountered in the more recent drilling to the north-west may be consistent with the well-documented mineralisation zonation of the similar Magma, Arizona lode-style copper-gold-silver system.

Stavely said that resource drilling is continuing on a 40m x 40m drilling grid with four rigs operating and two further large-capacity rigs have commenced deep drilling targeting the core of the underlying porphyries inferred from a recent seismic survey.

Stavely project

The Stavely Project is located in western Victoria on the Stavely tablelands approximately 250 km to the west of Melbourne.

The project has an existing large Inferred Mineral Resource of 28 million tonnes at 0.4% copper (gold and silver not estimated) at Thursday’s Gossan prospect.

The company’s shallow copper-gold discovery on the Ultramafic Contact Fault has been named Cayley Lode, located at the Thursday’s Gossan prospect.

Resource drilling programme at Thursday’s Gossan

The company had commenced a resource drilling programme at Thursday’s Gossan prospect within the Stavely project to delineate high-grade, near-surface copper-gold-silver mineralisation over a significant strike extent in the Cayley Lode that would complement the existing large Inferred Mineral Resource at Thursday’s Gossan.

SVY had made a discovery intercept of 32m at 5.88% Cu, 1.00g/t Au and 58g/t Ag in SMD050. The company’s recently released drill hole SMD104, located ~275m in the other direction to the south-east of discovery drill hole SMD050 had returned an exceptionally wide intercept including high-grade copper-gold-silver intercepts.

Significant intercepts included 144m at 1.04% Cu, 0.15g/t Au and 3.4g/t Ag from 35m down-hole, including 84m at 1.55% Cu, 0.23g/t Au and 5.0g/t Ag from 95m, including 28m at 3.31% Cu, 0.49g/t Au and 7.1g/t Ag from 151m.

Stavely said that the ongoing resource drilling at Cayley Lode discovery has now returned one of the most significant intercepts since its discovery in September last year.

Spectacular new intercept in SMD106

The company announced that diamond hole SMD106, located ~80m north-west along strike from the discovery intercept in SMD050 has reported spectacular new intercept.

SVY said that the diamond drill hole SMD106 intersected shallow high-grade copper-gold-silver mineralisation of 48m at 1.39% Cu, 6.33g/t Au and 12g/t Ag from 85m down-hole, including 16.7m at 3.13% Cu, 17.93g/t Au and 29g/t Ag from 115m, including 2m at 0.74% Cu, 132g/t Au and 38g/t Ag from 116m, and 0.9m at 21.10% Cu, 17.45g/t Au and 232g/t Ag from 130.8m.

The company said that the current focus of ongoing drilling is continuing to extend the shallow Cayley Lode mineralisation to the north-west.

SVY said that the significantly higher gold grades encountered in the more recent drilling to the north-west may be consistent with the well-documented mineralisation zonation of the similar Magma, Arizona lode-style copper-gold-silver system.

Stavely reported that based on this model, it is possible that the Cayley Lode is exhibiting a characteristic transition both spatially and temporally from a high-sulphidation copper sulphide assemblage to a more peripheral low-sulphidation assemblage, resulting in the higher gold grades to the north-west. The company said that the results from recently completed holes in this area may confirm this hypothesis.

Drilling to test the two interpreted porphyry targets

The Company announced that it plans to drill two ~1,500m deep drill holes to test the two interpreted porphyry targets announced recently.

SVY reported that the program has commenced with the first of the ~500m large-diameter pre-collars to be completed before the end of the year, then break for Christmas with sufficient time for the drillers and offsiders to complete any mandatory isolation before they sit down for Christmas lunch, and for them to return after New Year to resume the drill holes with medium-diameter drill core to the planned final depths of ~1,500m, with expected completion in February-March 2021

Updates and next steps

Stavely said that an intensive resource drill-out is continuing with a focus of extending the deposit to the north-west within the (now) 1.5km-long discovery zone, with in-fill and step-out drilling continuing based on a roughly 40m x 40m drilling grid. The company said that the Mineral Resource drill-out is well advanced and progressing well.

SVY said that once the near-surface potential is confirmed and some similar regional targets are tested, drilling will shift towards confirming the depth potential of the high-grade copper-gold-silver mineralisation on a number of mineralised structures including the Cayley Lode, the North-South Structure (NSS), and the Copper Lode Splay (CLS).

The company said that other structures that have the potential to host well-developed copper-gold mineralisation may be inferred from a recently completed seismic survey.

Management comments

Stavely Minerals’ Executive Chairman Chris Cairns said: “This is another pivotal moment in the history of the discovery, with an exceptional new intercept including a stunning high-grade gold component which eclipses the discovery intercept of 32m at 5.88% Cu, 1.00g/t Au and 58g/t Ag in metal equivalent / value terms.

It comes hard on the heels of the shallow 144m intercept just last week from SMD104, which was hailed as a timely reminder of the potential of our shallow resource drilling program to continue to produce spectacular intercepts of high-grade copper, gold and silver mineralisation.

Despite having made that prescient statement, we did not expect the very high-grade gold we have seen in SMD106. While we had nominated this drill hole for priority assay at the lab because we liked the look of the copper mineralisation – which is very visual – we have no easily recognised indicator of high-grade gold.

Elsewhere we have noted an association with lower temperature banded silica as a late in-fill to corroded voids and, on occasion, the manganese carbonate rhodocrosite and base metal sulphides sphalerite and galena. These are all indications of a cooler, more low-sulphidation character to the higher gold-grades, significantly above the more typical 0.25g/t Au to 0.50g/t Au grades we would normally see associated with well-developed lode-style copper mineralisation that displays a more high-sulphidation character.

We eagerly await additional drill results from extensional drilling in the north-west sector of the deposit.

One key characteristic of the best mineralised systems globally is that they are multi-phase and not simple. The more events occurring over an extended period of time – with different mineralising pulses over-printing earlier phases – the greater the chance of forming a deposit that may host the scale and grade required for a substantial long-life development.

This is the objective of our drilling programs as they evolve from defining the shallow resource to then extending the Cayley Lode mineralisation at depth and targeting additional known mineralised structures – the Copper Lode Splay and the North-South Structure.

We hope to define sufficient resources for a Phase 1 open pit development and then a multi-decade Phase 2 underground.

This is both the challenge and the opportunity in front of us and, while a solid house is built brick by brick, so too this Project is emerging as each significant drill intercept is added to the list.”