Sunridge Gold Corp. (CVE:SGC) announced Thursday a new 3.3 million tonne resource estimate for its Debarwa volcanogenic massive sulphide (VMS) deposit, part of the company's Asmara project in Eritrea.
The updated estimate, completed by AMC Consultants as part of an ongoing feasibility study on the copper-gold-zinc deposit, contains 200 million pounds of copper in the measured and indicated category, 180,000 ounces of gold, 2.94 million ounces of silver and 74 million pounds of zinc.
The new Debarwa estimate includes 83 additional holes that were completed since the last estimate in 2008, the company said.
Previously, the entire resource was either in the indicated or inferred categories, but the upgraded report now concludes there are 3.3 million tonnes of measured and indicated resources, and 681,000 tonnes of inferred resources.
"This new resource estimate is another major milestone towards bringing the Debarwa deposit into production," said president and CEO, Michael Hopley.
Debarwa is one of four deposits within the Asmara project, and is being studied as both a stand-alone deposit and as a potential feed to an operation in the northern part of the project, which includes the large Emba Derho deposit, the Adi Nefas zinc-gold copper prospect and the Gupo gold zone.
The underlying copper-enriched supergene zone of Debarwa is estimated to contain 158 million pounds of measured and indicated copper, with an average grade of a whopping 5.15% copper, said Sunridge.
Within this zone, there is an area of particularly high-grade copper, which AMC believes contains 41 million pounds of copper, with an average grade of 16%. This high grade zone occurs at about 50 metres from surface, over a strike length of around 140 metres within the copper supergene area.
"Recent drilling has been successful in upgrading parts of the resource to the Measured and Indicated categories, especially the high grade copper supergene zone of which 23% is now in the Measured category," added Hopley.
"We are particularly pleased that the very high-grade portion of the supergene zone is much larger than expected at a grade of 16% copper."
Meanwhile, measured and indicated resources also included a surface oxide gold cap zone, which was estimated to host 83,000 ounces of gold, at an average grade of 2.38 grams per tonne (g/t).
The Vancouver-based mineral explorer said that due to limited drill hole information in part of the oxide gold cap zone, caused by drill rig access problems, some material did not qualify as measured or indicated categories, and as a result, the number of tonnes in this area was reduced. However, average grade increased by about 40% compared to the last estimate in 2008, it added.
The feasibility study for Debarwa is expected by year-end, and will only consider material in the measured and indicated categories.
The company said the report will examine options to fast track the high grade portion of the copper supergene zone to production, including by mining, crushing and direct shipping directly to a smelter without the need for a concentrator.
The latest resource report is based on mineralization that extends over a strike length of 1,250 metres, using 314 holes, of which 268 were diamond core and 46 were reverse-circulation holes.Aside from Asmara, Sunridge, with roughly $16 million of cash in the bank, also has exploration properties in Madagascar.