Sihayo Pungkut Gold Project ? New JORC Compliant Estimate Sihayo Resource increases 43% to 1.30 Million ounces, total project resources grow to 1.4 million ounces
Highlights As a result of infill and resource extenstion drilling at the Sihayo resource a new JORC compliant resource estimate has been calculated and stands at: 14.6Mt at 2.8g/t Au for 1,302,000 oz 90% of the Sihayo resource is in the Indicated Category Resource tonnage has increased 53% and contained gold has increased 43% compared with the previous JORC compliant resource estimate released in July 2010 Sihayo resource remains open to the north, east and south. Total Sihayo ? Sambung, JORC estimate, stands at: 15.7Mt at 2.8g/t Au for 1,402,000 oz Pit optimisation and mine scheduling to be updated with new resource Definitive Feasibility Study (?DFS?) finalisation delayed to allow inclusion of new resource
The Board of Sihayo Gold Limited (ASX: SIH) is pleased to announce the new upgraded JORC compliant resource estimate of 14.6Mt at 2.8g/t Au containing 1,302,000 ounces of gold for the Sihayo resource within its 75% owned Sihayo Pungkut gold project in North Sumatra, Indonesia. The new estimate is based on an extensive infill and resource extension drilling program completed between July 2010 and March 2011. The upgraded estimate for the Sihayo resource takes the total project JORC compliant resource to 15.7Mt at 2.8g/t containing 1,402,000 ounces. Table 1 below details the updated resource estimates. The Company?s CEO, Mr Paul Willis, said ?Overall drilling results and the new resource figures are very encouraging and the substantial increase in contained gold is economically very significant. This new resource estimate is being included in the Definitive Feasibility Study (?DFS?), and supports our confidence in taking our first project forward to the production stage.?
?It is also clear that the resource is constrained by drilling in a number of directions and that mineralisation is expected to extend beyond the current resource outline. Ongoing exploration/resource extension drilling will continue to seek to identify the overall resource potential of the Sihayo area.?
The new resource estimate covers an area of approximately 1.4 km by 0.6km and is based on approximately 496 diamond drill holes which were drilled on a nominal 25 metre by 50 metre grid within the majority of the resource area with the more recent southern extension holes drilled on a nominal 50 metre by 50 metre grid.
The mineralisation at Sihayo is a silica (jasperoid) replacement style of mineralisation localized at lithological contacts, within a Permian limestone and marble sequence with interbedded volcanic and volcaniclastic units.
Drilling has identified three primary sub horizontal gold zones; an upper zone at the Permian limestone/Tertiary sedimentunconformable contact, a middle horizon at a marble/silty limestone interbed and a lower zone at a volcanic lava/silty limestone contact and a fourth zone of post surface weathering/oxidation of the primary lodes (regolith) occurring in modern karst environment.
The resource is exposed at surface at its northwestern end and extends to a depth of 200 metres along strike at its southeastern end. The resource is highly but variably oxidized to depths of about 40 metres and there are variable levels of oxidation down to about approximately 150 metres depth.
Infill drilling within the area of the previous resource has confirmed the continuity of the regolith mineralisation in thenorth lode area and defining the lower mineralised zone. Step out and extension drilling in the southern area identified a third lower mineralised zone at the volcanic/ silty limestone contact. This lower zone accounts for the majority of the resource increase. A zone of higher grade mineralisation at the Tertiary/Permian contact has been intersected in the south eastern area that will be the subject on ongoing drilling.
The Sihayo and Sambung Resources, depicted in Figure 1 below, are separated by about 1.25 km of potentially mineralised strike. Stratigraphy 0.75km to 1 km northwest of the Sihayo resource also yields gold mineralisation as defined by historic exploration. The combined strike length of this favorable stratigraphy is approximately 4.5 km. Mapping in these extension areas has located jasper outcrops, >0.1ppm semi continuous soil anomalies and limited drilling has previously returned results with >10 gram * metres gold intersections.
The exploration drilling program for the next 3‐6 months is designed to target favourable known horizons within the north and south extensions along strike from the Sihayo resource, primarily targeting shallow oxidized zones. The northern limit of the regolith mineralisation is not defined.
The resource estimate was completed by international industry consultants Runge Limited based on data and geological information supplied by PT Sorikmas Mining (75% owned subsidiary of Sihayo Gold Limited and 25% owned by PT Antam Tbk). No mining dilution has been included in the resource estimation.
The significant increase in the gold resource ounces necessitates that the pit optimisation and mine scheduling process be re‐worked and updated for inclusion in the DFS. Consequently, the finalisation and release of the DFS results will now occur later than the previously advised date of end of March 2011.
SIH Price at posting:
22.4¢ Sentiment: Buy Disclosure: Held
