Indonesia-focused explorer Sihayo Gold has followed up its recent high grade surface samples with strong diamond drilling assays from a 30-hole exploration program that has extended its Sihorbo South target and firmed up the modelling for its maiden mineral resource estimate. Sihorbo South is now shaping up as a satellite operation to the company’s main Sihayo Starter project.
Sihayo has been punching more than 5000m of diamond drill holes into the Sihorbo South epithermal gold-silver vein structure in the south-west corner of the large Hutabargot Julu prospect on the western side of Sumatra Island. It is about 6km from its main focus area, the historic Sihayo Starter project discovered and mined by the Dutch in the 1930s until World War II.
Headline results from Sihorbo South include a 3m intersection reading 25.15g/t gold equivalent with 24.88g/t gold and 20g/t silver from 112m and 7m grading 1.18g/t gold equivalent with 0.9g/t gold and 21g/t silver from 129m.
The strong numbers have spurred Sihayo’s geologists to model Sihorbo South for a maiden mineral resource and plan to incorporate the discovery into the Sihayo Starter project as a satellite operation.
Rich surface samples announced in April from the Tambang Tinggi prospect in the company’s southern block yielded up to 36.6g/t gold and 8.29 per cent copper.
Notably, of the 57 samples collected, a substantial 35 per cent yielded more than 1g/t gold, including five between 13.1g/t and 36.6g/t gold.
In addition, 33 per cent turned up more than 0.2 per cent copper, including five returning grades ranging between 2.08 and 8.29 per cent copper.
Sihayo says data so far indicates that the historical mining was highly selective with large amounts of the top of the vein remaining. The workings are believed to be generally less than 50m deep and more focused on mining softer, strongly oxidised vein material.
The company has temporarily switched focus from Sihorbo South whilst it plans the next round of exploration. However, it is also busy with a six-hole, 2000m drilling program testing for additional higher-grade gold mineralisation in deeper jasperoid lenses and potential high-grade feeder structures below the Sihayo 1 pit, that may support underground mining operations.
The company says the drilling results from Sihorbo South continue to illustrate the potential for the orebody to become a satellite operation.
Sihayo Gold’s Executive Chairman, Colin Moorhead said: “By utilising the existing infrastructure envisaged for the Sihayo Starter project, the incremental ounces from Sihorbo South have the potential to add considerable value to the project. We look forward to releasing a maiden mineral resource for the deposit shortly.”
In 2020 Sihayo announced an updated JORC 2012 compliant measured mineral resource estimate of 6.4Mt for 440,000 ounces of gold at 2.1g/t.
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By Matt Birney
