Sumatra Copper updates resource for Tembang project
Monday, September 5 2011 - 04:36 AM WIB
A 5,618 metre infill drilling program has further defined the resource and formed the basis of the upcoming Feasibility Study. The Company also carried out an extensive Specific Gravity verification of various lithological groups as recommended by Hellman and Schofield.
The project has a total combined resource of 22.6 million tonnes with 976,000 ounces of gold at a grade of 1.35 g/t Au and 12,794,000 ounces of silver at a grade of 17.6 g/t Ag. Further definition has been added to the ore zones, improving resource confidence in some key areas
Sumatra Chief Executive Officer Julian Ford said the updated resource produced in line with the JORC guidelines and the confirmation of Belinau?s potential as a stand alone underground resource gives the Company confidence to proceed with its two stage development plan at Tembang.
?Our strategy, as outlined in the June quarterly report, is to move our high grade Belinau deposit (as well as two smaller satellite pits) into production during stage 1. By doing so, we will substantially reduce the time and capital costs required to move into production.
We aim to move the remaining larger pits at Tembang into production following completion of stage 1", said Mr Ford.
?In line with our development plan, we published the Belinau Resource as a discrete underground resource using a higher cut-off grade.
"The latest resource is very similar to the previous global resource albeit with a tighter drill pattern and an increased data set. We will provide an updated development plan and schedule in the coming weeks.?
Increased Definition at Belinau and Berenai
The infill drilling program succeeded in better defining the resource at Belinau and Berenai, with further scope to add to Berenai?s resource following the extension of the southern high grade shoot which still remains open at depth.
Drilling at Belinau increased the size of the Northern high grade shoot and gave further definition to the Southern high grade shoot. The size and grade of the Belinau resource now constitutes a stand alone potential underground resource. Both high grade shoots at
Belinau are now closed off, though potential remains to explore for additional vein development along the strike of this highly prospective structural corridor.
Follow up work on rock densities has added a much better defined set of density values for modeling. Tighter search parameters have resulted in a reduction in inferred resources and a limitation on the influence of high grade assays. Drilling at Buluh and Bujang trimmed away some inferred high grades.
A revision of the use of density data has resulted in a slight loss of tonnage in the veins as the Company now models density values for each block which recognises that in some areas the vein includes intercalated mineralised wall rocks which have lighter densities. Halo mineralisation, renamed as peripheral sheeted veins (PSV) to more correctly reflect the style of mineralisation, saw a 5% drop in tonnages due to the revision downwards by some 20% for the density of oxidized zone.
As with the previous March resource the new model and estimate have been reviewed by Hellman & Schofield.
The principal differences between this and the March 2011 resource lie in the revisions to the density values used and their application, estimated for each block, inferred, and the change to a higher reporting cut-off for Belinau to reflect the change in mining method. (ends)