The new high grade drill intercepts at Sumatra Copper and Gold's (ASX: SUM) Tembang project in south Sumatra province hint at the tantalising promise of Tembang being part of larger epithermal system and that higher grade zones may exist at depth, that were not previousl mined by Barisan Tropical Mining.
As well, the Company’s current mineral resource, which is based primarily on previous BTM drill data, does not currently fully reflect this higher grade potential.
Managing Director, Jocelyn Waller said "latest drill intercepts at Berenai demonstrate another high grade shoot at depth following similar phenomena delineated at Belinau and Nuri and is suggesting to us that the relatively low grade resources (1.64 million oz) already established near surface at Tembang may in fact be the upper manifestation of a larger, deeper and richer epithermal system."
"If that proves to be the case then it will fundamentally alter previous perceptions and lead to a reappraisal of the deposit’s economics and exploitation possibilities. This is an exciting development and our intent is to follow this current highly successful drill programme with a further 10,000 metres of confirmatory and extension drilling that will include three 500 metre holes targeting the apparent confluence of the Berenai and Nuri shoots at depth.
The Tembang project is located approximately 120 kilometres north-northeast of Bengkulu in South Sumatra province. Tembang is a large intermediate-sulphidation epithermal deposit comprising gold-silver bearing quartz veins hosted by Tertiary volcanics.
A total of 26 holes have been completed during the current programme of diamond drilling designed to test the down dip extensions of the higher grade vein systems at Buluh, Bujang, Nuri and Belinau.
Results have now been received for 4 holes drilled into the main Berenai vein. current drilling has concentrated on the southern shoot and has succeeded in pushing the shoot deeper with continuing high grades.
Best results included: RDD10064 13.3 metres @ 2.91g/t Au, 3.5g/t Ag including 2.8metres grading 8.13g/t Au, 1.4g/t Ag, RDD10066 15.15 metres @ 4.94g/t Au, 5.0g/t Ag including 7.1 metres grading 9.39g/t Au, 7.1g/t Ag and RDD10067 5.6 metres @ 6.91g/t Au, 87.7g/t Ag including 3.1 metres grading 12.12g/t Au,
89.4g/t Ag.
Further step out drilling will require a larger rig than the one currently on-site; the larger rig will also allow drilling of the northern high grade shoot.
The Company has rights to two IUPs totalling an area of some 850 km² over and around the former Rawas mine that operated between 1997 and 2000.
The vein systems analysed to date suggests that considerable depth potential exists for higher grade shoots extending below the known vein systems, in particular below the largest vein/halo system mined to date at Berenai/Nuri. Tembang is most likely an intermediate sulphidation epithermal vein system similar to our own Lebong Tandai and the Co-O mine complex in the Philippines. By analogy, Tembang could potentially have shoots that extend > 200 metres downdip.
A major drilling program is being prepared to further explore and define these higher grade shoots underneath what appears to be a lower grade cap.
These holes hold the promise to multiply the resource potential of Tembang several times.