Sumatra Copper & Gold has released its annual JORC-compliant mineral resource and ore reserve statement for the Tembang Gold-Silver Project in Southern Sumatra, Indonesia, as at December 31, 2016. The statement takes into account mining depletion during 2016 and results of exploration.
There are total measured, indicated and inferred resources of 6.102 million tonnes at 2.0 g/t gold and 24 g/t silver for 387,000 ounces of gold and 4.614 million ounces of silver.
The underground resource at December 31 was 279,000 tonnes @ 8.6 g/t gold and 54 g/t silver for 78,000 ounces of gold and 485,000 ounces of silver. The open pit resource was 5.823 million tonnes @ 1.7 g/t gold and 22 g/t silver for 310,000 gold ounces and 4.129 million silver ounces.
The total proven and probable reserves were 1.647 million tonnes @ 2.5 g/t gold and 26.9 g/t silver for 132,000 ounces of gold and 1.426 million ounces of silver.
The underground reserve was 387,000 tonnes @ 4.4 g/t gold and 29.2 g/t silver for 55,000 gold ounces and 363,000 silver ounces. The open pit reserve was 1.260 million @ 1.9 g/t gold and 26.2 g/t silver for 77,000 gold ounces and 1.062 million silver ounces.
Mineral resources are reported inclusive of ore reserves and include all exploration and resource definition drilling information and mining production data up to December 31. Resources have been depleted for mining to December 31. Other adjustments have been made to interpretations and modelling to reflect ongoing mining information received up to March 25, 2017, if considered material.
The review and update for the Belinau and Berenai gold-silver deposits at Tembang was carried out by Cube Consulting of Perth, Western Australia. These deposits are subject to underground and open-pit mining operations respectively.
The Belinau resource is being exploited from underground via decline access from within the former Belinau open pit. The Berenai resource estimate encompasses the Berenai, Nuri and Central vein systems, within one open pit mining operation.
During the March quarter the company produced 5159 ounces of gold and 50,555 ounces of silver from Tembang at an all-in sustaining cost of US$1527 per ounce. Gold recovery was 93.4% and silver recovery was 79.9%
The Belinau underground operation transitioned from bench cut and fill to shrink stoping, commencing from Level 9. The Berenai open pit experienced reduced production due to an inaccurate pre-2007 survey. Guidance for 2017 remains unchanged at 45,000-55,000 gold-equivalent ounces.
Sumatra says near-mine exploration activities continue to focus on advancing priority targets in the Tembang exploration target pipeline towards drill testing.