JORC 2012 Mineral Resource Estimate
The JORC 2012 mineral resource estimate was carried out by MPR Geological Consultants Pty Ltd (“MPR”).
The drill hole database utilised for the resource modelling was compiled by MPR from the extensive digital database available from extensive data sets from previous evaluation of Buena Vista.
Mineralised domain wire-frames used for the resource modelling were interpreted from 3.05-metre down-hole composited Fe grades from the diamond and RC drilling. The domains captured zones of continuous Fe grades greater than approximately 10% and for the West Deposit were trimmed by several steeply dipping dykes the wire-frames interpreted from drill hole logging and Fe grades.
The combined mineralised domains lie within a corridor of around 3,300 metres by 500 metres and extend from surface to a depth of around 240 metres. Around 90% of the mineralisation lies within 140 metres of the surface.
Total Fe, DTR mass recovery and density were estimated by ordinary kriging of 3.05-metre down-hole composited grades within the mineralised domains. Densities were assigned to drill hole intervals from an Fe-density function.
The resource modelling did not employ upper Fe grade cuts reflecting the low to moderate variability of the attributes and lack of extreme Fe values.
The indicated and Inferred mineral resource estimates were extrapolated to a maximum of generally around 40 metres and 60 metres from drill intercepts respectively.
Micromine software was used for the initial data compilation, domain wire-framing calculating and coding of composite values.
*DTR% is the estimated proportion of the rock mass recoverable by simple magnetic concentration estimated on the basis of the Davis Tube Recovery analyses for drill hole samples. It is strongly correlated to iron grades.
GS3M was used for Kriging and the estimates then imported into a Micromine block model for reporting.
Model validation included visual comparison of model estimates, composite grades, comparison with historic estimates and trend (swath) plots.
All tonnages were estimated on a dry basis and the estimates reflect medium scale open pit mining.
The resource estimate has been carried out across Total Fe cut-off grades of 10.0%, 15.0%, 20.0% and 25.0%. Because of the favourable beneficiation characteristics of the Buena Vista ore the lower cut-off of 10.0% Total Fe has been chosen to represent the headline resource estimate.