Geology and mineralisation of the Mewet Vein, Jelai Gold Project ...

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PT GMT Indonesia Mewet Vein : Jelai Gold Project 11 11.1 DATA VERIFICATION AND INTERPRETATION Validation To update the database and ensure the data integrity was acceptable for future use, we applied a three stage validation process. Data validation routines were conducted were: • Verification of the files supplied by JCM and historical files from Ivanhoe, • Upload and compilation of the files in Access, ensuring samples and assays matched and the drill hole collars plotted were consistent with location data and historical plans, • Validation of the database through internal Surpac routines. Discrepancies in each stage were verified and checked, then corrected. Most of the errors were resolved in the compilation of the Access database and only minor errors were reported from further detailed validation. The lithological database was filtered and litho-codes standardised for easy manipulation at a later stage if required. The list of rock codes used in the geological validation is outlined in Table 7. Code FLT HBX QV SED SOL VA VAL VBL VBX VDP VRD Description Fault gouge, breccia, post mineralisation Hydrothermal breccia, vein breccia, clast or matrix support, exotic matrix fill Quartz vein, massive or colloform-crustiform Sedimentary rocks, undifferentiated Soil, alluvium, colluvium Andesite, undifferentiated Andesite lava, undifferentiated Basalt Volcanic breccia, dominantly andesitic Dacite porphyry, stock or dyke Rhyolite, intrusive stock or dyke, flow-banded Table 7. Lithocodes for the Jelai Gold Project database. 11.2 Sampling Data The original sampling data from the Ivanhoe exploration was databased in an Access database with original digital files from the assay laboratory imported through a set routine. The matching of assay results to assay intervals was made using SQL queries and no manual matching of the assay data was undertaken by Ivanhoe. At the time, a number of checks were conducted on the analytical data matching and, in the latest data review, the same matching routine was used from the original datasets. The original analytical sheets are archived with JCM. The JCM assay data was matched by copying from the original analysis files into the Excel spreadsheet. Although there is some chance of mis-matching samples, the sample runs were generally short and the various checks by JCM and GMT staff throughout the programme corrected errors when they became apparent. A series of 10 individual analytical run results were checked during the course of this study and no errors were located in the transformation of the data. 0065 JCM/GEO/2009.04 Page 34
PT GMT Indonesia Mewet Vein : Jelai Gold Project 11.3 Database Compilation The validation has resulted in a complete data set that would be suitable for further follow-up modelling if desired, particularly for the Mewet Vein area. It is also believed there is sufficient data from the Sembawang Vein, in some sections, that also could be modelled and this requires further assessment. The resulting confidence level of the present data set is outlined in Table 8. Technical Condition Comments Confidence Geological model The geological model is well known for epithermal deposits and, although there are numerous variants, the chemistry and dynamics of High the systems are well documented Prospect geology The broad prospect geology is known but detailed structural data is limited for both surface and sub-surface areas, the real control on the Moderate development of ore shoots is not yet clear Alteration and Drilling has provided a broad understanding of the alteration and the mineralisation styles mineralisation position with respect to the precious metal values Moderate Drill collar positions No drill collars have been surveyed fully, in cases tied by tape and compass to control benchmarks, prone to have some errors Low Downhole geology Individual interpretations of the geology can lead to some mis-coding of Moderate to rock and mineralised intervals, simple geology has offset this weighting high with clear mineralised zones seen in the core Downhole survey Incomplete, Ivanhoe holes were generally surveyed, the JCM holes Moderate Core recovery Sample density Historical data have no surveys Some drill sections have poor core recovery, requiring weighting during compositing and lowering the confidence in the composite interval accuracy regarding precious metal grade The drilling interval on some sections remains at 25-50 metres, particularly in critical areas, more infill drilling is required The authors knowledge of the previous data allows the historical data to be viewed with higher reliability Low to moderate Moderate Present data The authors knowledge of the recent exploration allows a high reliability High Sample administration The systems in place and procedures used are generally acceptable and industry standard High QA/QC The analytical repeats are good and there is not major discrepancy between principal and check assays, external lab control is required in Moderate the future, as are blanks and standards in the main sample stream. Chain of custody Sample chain of custody is an area that could be reviewed Moderate Data administration The data sets are well-archived and are generally accurate, the storage system is adequate for the quantity of data being processed High Density factors Requires measurements in both waste and ore material Low Database integrity No major issues identified High Table 8. Considerations in assessing the exploration data, showing the confidence in the data set and the areas requiring further management. High 11.4 Analysis of Data 11.4.1 Topography The topographic surface was generated using surveyed topographic data still available from the original exploration data of Ivanhoe Mines Limited for the vein outcrop area and, for areas to the west where no data is available, the drill hole collars were triangulated to form the topography. The area immediately west of the ridgeline is a flat alluvial terrace adjacent to the Sungai Mewet 0065 JCM/GEO/2009.04 Page 35
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Geology and mineralisation of the Mewet Vein, Jelai Gold Project ...

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