Criteria

Status

Havilah drillholes used in resource estimation

• 51 RC holes totalling 5,379m, drilled by Havilah Resources, were used in defining the resource. There were no previous drillholes in the region prior to Havilah's work. 

Drilling techniques

• All RC holes were drilled using standard face sampling hammers with bit sizes ranging from 121mm to 133mm.

Sampling techniques

• Havilah RC samples were collected at 1m intervals. All bagged samples were initially assayed with a calibrated Niton XRF analyzer, with three separate 15 second readings being averaged for each sample.
• For intervals assaying over 15% Fe, approximately 0.75kg of sample was collected from each sample bag by either rifflle splitting or spear (no measurable method induced difference was detected) and composited over a 3m interval to produce 2-3kg assay samples. The composite samples were sent to the lab, where they were dried and pulverized in a mixer mill. A disk was prepared from the pulp for Fusion XRF analysis.

Drill sample recovery

• Havilah RC sample quality & recovery was continuously logged; overall both were excellent. In the rare instances when sample quality was unacceptable the cause was high water flow in extremely fractured rock.

Logging

• All Havilah RC holes were logged by experienced geologists with the data directly entered into a digital logging system, from where the data was uploaded into an Excel spreadsheet.
• All Havilah drill chip trays are stored at Havilah's camp at Yarramba Station.

Quality of assay data and laboratory tests

• Havilah samples were assayed by ALS via the Fusion XRF method. This provided a complete whole rock XRF analysis for each sample.
• Havilah monitored assay data accuracy and precision via least squares regression analysis comparing ALS results with the Niton XRF field results. Overall correlation of results was extremely good with correlation coefficients typically exceeding 0.9. When scatter occurred it frequently related to wet samples. The Niton results are consistently 1-4% lower than the ALS results; this difference is attributed to: the moisture in the field samples, attenuation by the plastic sample bags, and variability of the distance between the sample and Niton probe.
• No data quality issues were identified.

Verification of drilling methods and sampling

• The only drilling technique used was RC ; no specific twinned diamond core holes were drilled. Given the relatively high iron contents in the ore zone (>15%) it is difficult to see how there could be significant variation between drilling methods, provided recoveries were at all times acceptable.
  

Location of drillholes

• Havilah's drillhole collar coordinates were surveyed in UTM coordinates using a differential GPS system with an x:y:z accuracy better than 20cm:20cm:40cm.
  
• Havilah's RC holes were surveyed using a digital multi shot survey camera, at nominal 10m intervals downhole.

Drillhole spacing and distribution

• Initially Havilah's RC drillholes were spaced at 50m intervals on lines 100m apart. Once the orebody's horizontal nature and continuity were realized, the holes were drilled on a staggered 100mx100m grid.
  
• Resource drilling is predominantly concentrated between 464700E and 465800E and between 6413700N and 6412800N.

Estimating and Reporting of Mineral Resources

Database integrity

• Havilah's database was progressively built up as new data was added to it, and quality control checks were made. Examination of the database has not revealed any issues that could significantly affect the current resource estimation.

Geological interpretation

• The Maldorky iron ore resource is hosted by the regionally extensive Neoproterozoic Braemar Iron Formation. It is normally steeply to shallowly dipping and may be up to 200m thick, comprising multiple iron formation and interbedded tillite horizons.
  
• The subhorizontal nature of the deposit and apparent thickening of the Braemar Iron Formation at Maldorky are interpreted to have resulted from the combined influence of tight drag folding and shearing.

Estimation and Modelling Techniques

• Polygons and hence triangulations are based on interpretations completed on nominal 100m sections.
  
• Triangulated interpretations were generated based on geological criteria and a natural assay break at around
  15-18% Fe.
  
• The block model was constructed with parent blocks of 20mE by 20mN by 10mRL with sub blocks available to a minimum of 2mE by 2mN by 1mRL.
  
• Inverse distance was used to estimate Fe grades and specific gravity.
  
• Multiple estimation passes with varying search neighbourhood sizes were run to ensure the accuracy of the result.
  
• The search directions for each estimation were aligned with relevant geological correlations and distances based on drill hole spacing.
  
• 3m assay composites were used with length weighting used in estimation.
  
• A minimum of 2 and maximum of 10 composites were used per estimate.

Moisture

• Tonnes have been estimated on a dry basis.

Cut-off parameters

• The bounding ore envelope was largely defined by geological and assay criteria.
  
• The block modeller calculated the volumes and average grades within the bounding ore envelope for Fe cut-offs of 0%, 15% and 18%.
  

Bulk density

• Density values were measured by Optimet Laboratories in their Adelaide lab for samples with a range of iron contents. From this, an iron density relationship was established, and each block was assigned a density based on its iron content.

Classification

• Mineral resources have been classified as Indicated based on the overall high quality of the drillhole samples and assay data, and high degree of confidence in the continuity of mineralisation balanced against the drill hole spacing (100mx100m).
  
• The orebody is both continuous and predictable. There is little apparent inherent variability in the grades, even at this drill spacing, and there appears to be a natural orebody wide grade cut-off or discontinuity at 15-18% Fe.