A new gold-silver zone at Barton Gold’s (ASX: BGD) (OTCQB: BGDFF) Tolmer prospect in South Australia has returned more high-grade assays and positioned the discovery as a potential third revenue stream alongside the company’s advanced Tarcoola and Tunkillia projects.

The assays have extended Tarcoola’s mineralisation within a shallow and broadening western “silver zone” and a shallow “gold zone” approximately 1 kilometre to the east.

They follow results from a November campaign that returned some of the highest-grade silver drilled in Australia to date, including a bonanza near-surface grade of 17,600 grams per tonne, independent of gold and within a broad halo of anomalous lead mineralisation.

Best new assays

Best new assays from the silver zone were 4m at 1,417g/t silver from 9m including 1m at 3,790g/t from 9m and 23m at 95g/t silver from 4m.

At the gold zone, Barton reported highlights of 5m at 3.07g/t gold from 16m, 5m at 4.38g/t gold from 49m including 1m at 13.6g/t from 52m and 15m at 1.07g/t gold from 51m including 4m at 1.90g/t from 51m.

According to the company, the new intersections infill and extend broad and high-grade silver and gold mineralisation to the west within interpreted oxide and transitional zones.

Gold within silver

Barton also encountered high-grade gold within the highest-grade silver in one of the Tolmer drill holes that sits at the boundary of oxidised and fresh zones of mineralisation.

The company will carry out further evaluation to ascertain whether any portion of the high-grade gold sits in fresh rock and determine the potential for this mineralisation to complement the high-grade silver.

A follow-up geochemical and drilling program is now underway with a view to mapping and testing the potential western, northern and southern extensions of the new silver zone.

High-grade bonus

Barton managing director Alexander Scanlon said the discovery of dual high-grade zones was a bonus for the Tarcoola project.

“High-grade standalone silver has been a big surprise in a 130-year-old high-grade goldfield,” he said.

“It is a huge free kick which could bring in a whole new wave of enthusiastic precious metals investors and could be a leading indicator of a more significant underlying gold deposit.”

“We are yet to find out what is in the fresh rock but it could potentially be used in our [Tarcoola] Stage 1 and 2 operations as a high-grade blending feed, driving up the project’s economics and driving down our all-in sustaining costs.”

Third revenue stream

Mr Scanlon believes Tolmer could become a third low-cost, high-revenue stream in parallel with Tarcoola.

“If this new high-grade transitional blanket extends north and south, we could be looking at a standalone silver oxide deposit to be mined in a simple open pit operation, screened and upgraded and direct-shipped to high-tech industrial producers such as those in Japan,” he said.

Tolmer is located approximately 5km west of Barton’s Perseverance mine at Tarcoola, 130km south-east of the fully-permitted Central Gawler mill and 70km north-west of the neighbouring Tunkillia gold project.

Barton believes this central location will provide multiple potential future commercialisation opportunities for the blending of high-grade gold and silver mineralisation into Central Gawler or the planned Tunkillia mill.

Edison research report

Earlier this month, Barton received the tick of approval from UK-based Edison Investment Research based on significant development opportunities within the company’s Tarcoola and Tunkillia portfolio.

Edison’s valuation reinforced the importance of the Central Gawler mill, valuing it at $0.46 per share on an ‘as new’ replacement cost basis and $0.23/share on an ‘as is’ indemnity value basis.

The valuation effectively covered Barton’s share price at the time.