Icon Resources Ltd ACN 115 009 106 Suite 505, 35 Lime Street, Sydney NSW 2000. Telephone: +61 (0)2 9279 1252 Facsimile: +61 (0)2 9279 2727 15 October, 2010 ASX Announcement Mt Carbine Deposit – Maiden JORC Resource Icon Resources Ltd (‘Icon’) is pleased to provide the following report on the Company’s Mt Carbine tungsten project in north Queensland. Highlights • A Maiden JORC compliant Inferred Resource of 113.6Mt at 0.06% WO 3 , containing 68,800 tonnes of tungsten trioxide has been estimated for the primary (hard-rock) mineralisation at Mt Carbine. • Estimation of the resource using a 0.05% WO 3 cut-off reports 39.8Mt at 0.14% WO 3 for 57,500 tonnes of tungsten trioxide beneath and adjacent to the existing open cut. • Drilling confirms continuity of mineralisation which remains open at depth and to the north, and along strike to the northwest Managing Director Dr John Bishop said: “This maiden JORC Inferred Resource is a 40% increase on our previous model and confirms the potential for significant long-term tungsten production at Mt Carbine. The drilling that led to this increase was mostly confined to the near-pit region and exploration of the extensive areas of adjacent historic tungsten workings has yet to be undertaken. “In the coming weeks the results of ongoing testwork on the tailings and mineralised waste stockpiles, including on-site ore sorter trials, will be used to fast-track production to meet a resurgent global demand for tungsten concentrates.” For personal use only
5
Embed
Mt Carbine Deposit – Maiden JORC Resource · Geostat constructed a total of 24 orezone wireframes, using Gemcom GEMS 6.2.4 software to represent all defined tungsten mineralisation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Mt Carbine Inferred Resource - perspective view of the 2010 block model showing the distribution of
blocks above 0.1% WO3, drillhole traces and the bounding South Wall Fault.
Dr John Bishop
Managing Director
Competent Persons Statement The information in this report that relates to Mineral Resources was compiled by Ms Fleur Muller. Ms Muller, who is a Member of the Australasian Institute of Mining and Metallurgy, is a full time employee of Geostat Services Pty Ltd and produced the Mineral Resource Estimate based on data and geological information supplied by Icon. Ms Muller has sufficient relevant experience to the style of mineralisation and type of deposit under consideration and to the activities undertaken to qualify as a Competent Person as defined in the 2004 edition of the “Australasian Code for Reporting of Exploration Results, Minerals Resources and Ore Reserves”. Ms Muller consents to the inclusion in this report of the matters based on her information in the form and context that the information appears.
Appendix A - Resource Estimation Methodology Resource Database Exploration data used to evaluate the Mt Carbine Mineral Resource was provided to Geostat in an Access database format on 24
th
September 2010, containing information for a total of 56 diamond holes representing 13,195m. The database comprises 39 historical diamond holes, and 17 diamond holes drilled by Icon totalling 4,973m during 2010. The database includes 273 downhole survey records, 11,742 vein intervals, 69 fault intercepts and 4,538 sample intervals with assay results for WO3%. Multi-element analysis was undertaken but only WO3% was considered for resource estimation. Sample data supplied includes a mixture of WO3% assay results and visual estimates. All WO3% assay results were determined from XRF analysis at ALS, Brisbane. The visual estimate methodology is based on the amount of quartz and tungsten being determined visually on diamond drillcore and then recorded as a percentage of drillcore. Extensive QAQC analyses involving comparisons of visual estimates against XRF WO3% assay results over the same sample intervals have shown a consistent linear relationship with no issues that would impact on resource estimation. Two digital terrain models were also supplied to Geostat, one representing the pre-mining topography, and the other representing the pit excavation surface. Modelling of Mineralisation Geostat constructed a total of 24 orezone wireframes, using Gemcom GEMS 6.2.4 software to represent all defined tungsten mineralisation at Mt Carbine. Wireframes were based on frequency of quartz veining and presence of sampling intervals, since mineralisation is associated principally with quartz veining. Assays were composited to 1m intervals. A wireframe representing the south-west fault which terminates mineralisation to the south was also constructed by Geostat, using fault intercepts from diamond drilling. Orezone wireframes were subsequently clipped to this fault. A topcut of 4% WO3 representing the 99.8
th percentile was applied to all orezones, to limit the influence of extreme values during
interpolation whilst preserving the overall tungsten grade distribution. Density A total of 610 density measurements from drillcore were supplied to Geostat. The methodology of density measurements was as follows: A length of solid and intact/unbroken core with essentially zero porosity was selected and the ends carefully cut with a diamond saw to make a near perfect cylinder. The core was then sun-dried and the length and diameter of the cylinder (average of three readings with calipers) and an accurate weight recorded to permit a simple volume/dry weight density estimate. Density measurements were analysed for any spatial trends by easting, northing and depth, with no obvious trends detected. Hence, an average density of 2.74 was applied to the whole deposit. Resource Estimation Variography analysis using lognormal variograms was performed on composite data to characterise spatial continuity and determine parameters for the resource model. A high nugget effect of 70% of the total variability is present, reflecting the nuggety nature of tungsten within the quartz veins. Spatial trends as analysed from variography characterise the mineralisation as striking southeast-northwest, with a vertical dip. No plunge component was detected in the dip plane. A block model using parent blocks of 10m x 20m x 5m size (Y x X x Z) subdivided into sub-blocks of 5m x 10m x 2.5m was generated using Gemcom SURPAC 6.1.3 software. The wireframes were used to limit the blocks available for grade interpolation, using block centroid locations to define blocks and sub-blocks for interpolation. Ordinary kriging using parameters from the back-transformed log variograms was used to estimate WO3 %, with each orezone treated as a hard boundary. A minimum of 5 samples and maximum of 30 samples were used to interpolate grades into each block, with the number of composites from each drillhole limited to 15. A discretisation array of 5 x 5 x 5 was used to refine the kriging weights for each model block. Search ellipses comprised 100m x 25m x 75m (along-strike x across-strike x vertical) for the initial interpolation pass, with search ellipses doubled in a subsequent pass. The block model was validated by several methods including visual validations on-screen, global statistical comparison of input declustered grades and block grades, and local grade/easting and grade/depth relationships. The Mineral Resource is classified as Inferred and Exploration Target, primarily based on distance from drillholes and confidence in spatial continuity as defined by variography. A 3D surface was constructed from sectional interpretations to form this boundary separating the two classifications, approximating a depth distance of 50m to 100m below existing intercepts. An additional constraint of 22350mE was imposed, with blocks east of this boundary classified as Inferred, and west classified as Exploration Target. Drillholes to the west of this boundary are sparse and step out in spacing, hence this boundary was deemed appropriate as forming the western limit of the Inferred resource. Blocks classified as Inferred are assessed as meeting “reasonable prospects for economic extraction” as defined in the Australasian Code for Reporting of Exploration Results, Minerals Resources and Ore Reserves.