Kingston Resources’ (ASX: KSN) latest drilling at the historic Misima gold mine in Papua New Guinea has confirmed the potential to increase the existing 3.6 million ounce gold resource.
Resource in-fill drilling at the Kulumalia prospect, located at the southern end of the main Umana ore body, has returned several positive assay results.
These include 10.7m at 1.34 grams per tonne gold and 8.10g/t silver, 7m at 1.14g/t gold and 15.71g/t silver, and 9.1m at 1.6g/t gold and 10.52g/t silver, with all holes including higher grade sections.
In addition, Kingston says “significant” high-grade silver assays within, and immediately adjacent to, the gold mineralisation have enhanced the potential economics of the Kulumalia area.
One hole hit three separate areas of silver mineralisation: 7.2m at 149.83g/t, 6m at 39.67g/t and 17.9m at 33.01g/t.
Other holes produced assays of 21.5m at 62.32g/t silver, 13m at 59.26g/t and 2m at 163g/t from 3m down hole.
Hole 99 intersected five zones of silver, including 3.6m at 194.94g/t.
Silver zones could add value
In November Kingston released its pre-feasibility study (PFS) for Misima showing that it could bring back to life the 130-year-old Misima mine, producing about 130,000 ounces per annum over a 17-years.
The PFS indicated gold could be produced at an all-in sustaining cost of A$1,159 per ounce over the life of the mine.
Misima is located on the island of the same name that lies in the Solomon Sea east of the PNG mainland and is part of Milne Bay province.
It is regarded as one of the great gold mines of the Asia Pacific, with gold discovered there in 1888 and last mining taking place in 2004, with the closure brought about by the then low gold price.
Now the company says silver mineralisation could add value to the life-of-mine.
Managing director Andrew Corbett says he is delighted by the quality of these latest assays from Kulumalia.
“The closer-spaced drilling at Kulumalia has further enhanced our understanding of this part of the Umana orebody,” he said.
He is confident these results will be included in an updated ore reserve later this year.
“Further, the discovery of new zones of shallow gold mineralisation within the current resource pit shell, as well as high-grade silver zones, are both significant developments for the potential economics of these sectors of the deposit,” Mr Corbett added.
Historic mining produced significant silver
In 1989 Canada’s Placer Dome revived mining there at Misima, producing 3.6Moz of gold over 15 years.
But the Canadians also mined 22.6Moz of silver up to 2004.
Kingston says that, at Kulumalia, high-grade silver mineralisation occurs both coincident with, and peripheral to, the main gold-rich zones targeted by the drilling.
“High silver grades have the potential to improve the economics of mining at Kulumalia due to the silver credits gained offsetting the gold production costs,” Kingston noted.
The company is at present studying the relationship between the gold and silver mineralisation so it can identify other potential silver targets.