Intrepid Mines says its Tujuh Bukit mine area under potential review
Saturday, February 25 2012 - 04:24 AM WIB
Intrepid Mines Limited, an Australian-based gold and silver development and exploration company, said its Tujuh Bukit gold and silver project may be reviewed over its forest and land status.
?Intrepid?s alliance partner, PT IMN, is working with relevant Indonesian authorities regarding a potential review of forest land status. There is no assurance that the forestry reclassification will take place in this instance,? the company said.
PT IMN received an extension of the forestry exploration permit dated 7 July 2010, which allows for exploration activities within forestry areas.
The Indonesian forestry law restricts non forestry activities within protected forests and prohibits mining using an open pit method in protected forest areas. The area of the porphyry copper-gold resource estimate, and the Zone A, Zone B and Zone C oxide resource estimate areas fall within a protected forest area.
Intrepid also disclosed strict control over its sample laboratory testing. It said it exercises a strict chain of sample custody in its drilling program at Tujuh Bukit.
Samples are securely packaged, batched, and then transported under supervision to Intertek's laboratory facility in Jakarta. At the laboratory, the samples are prepared by crushing and pulverizing and a 30 gram charge is assayed for gold by conventional fire assay and/or atomic absorption methods.
Multi-element ICP analysis is carried out using a multi-acid digestion process. All samples that contain silver and/or copper, lead, and zinc values that exceed the upper detection limits for ICP are re-analysed by conventional atomic absorption methods to determine the absolute values of these metals.
Resources estimates
Geological interpretations of the copper mineralization provided by Intrepid were used to define a "top-of-porphyry" surface to restrict estimates to geologically reasonable limits. The block model was coded by oxidation zone and estimates were restricted to the sulphide or transitional zones as well as to the potential porphyry zone.
The 6m length-weighted composites from the transitional and sulphide zones were used to estimate, via Ordinary Kriging, Cu, Au, Mo, As, SG and Ag into a 40 x 40 x 15 meter block model. Silver values within the primary mineralization are low (eg < 5g/t) and their estimates are not reported.
Inferred Resources are defined on the basis of a 120m x 120m x 80m search ellipsoid using a maximum of 32 6m composites and a minimum of 12. Two more passes to 240m x 240m x 160m were used to generate "potential" blocks within the constraints of the porphyry model. In general, these potential blocks define extra similar tonnages at similar grades to the quoted estimates.
These, however, do not constitute "resource estimates" and there is no guarantee that they will be upgraded to resources with further drilling. Drill spacing of the deeper holes is approximately 200m x 200m. However, there are a considerable number of shallower holes that intersected copper mineralization in transitional and primary mineralization.
It said approximately 5% of quoted resources are from transitional mineralization, 5172 6m composites of Cu and Au are available for estimation together with 5072 Mo, 4955 As and 3446 SG values. Composites from the porphyry zone number 2408, 2408, 2379, 2402 and 1684 for Cu, Au, Mo, As & SG, respectively.
Editing by Roffie Kurniawan