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Criteria
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JORC Code
explanation
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Commentary
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Database
integrity
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- Measures taken to ensure that data
has not been corrupted by, for example, transcription or keying
errors, between its initial collection and its use for Mineral
Resource estimation purposes.
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- Data used in the Mineral Resource
estimate is sourced from a data base export. Relevant tables from
the data base are exported to MS Excel format and converted to csv
format for import into Datamine Studio 3 software for use in the
Mineral Resource estimate.
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- Data validation procedures
used.
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- Validation of the data import include
checks for overlapping intervals, missing survey data, missing
assay data, missing lithological data, and missing
collars.
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Site
visits
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- Comment on any site visits
undertaken by the Competent Person and the outcome of those
visits.
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- A representative of the Competent
Person (CP) has visited the project on several occasions, most
recently in July 2014. Diamond drilling programs were underway at
Mabilo during the most recent site visit. The CP's representative
was able to review drilling and sampling procedures, as well as
examine the mineralisation occurrence and associated geological
features. Sample storage facilities and the analytical laboratory
in Manilla have also been inspected. There were no negative
outcomes from any of the above inspections, and all samples and
geological data were deemed fit for use in the Mineral Resource
estimate.
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- If no site visits have been
undertaken indicate why this is the case.
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Geological
interpretation
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- Confidence in (or conversely, the
uncertainty of) the geological interpretation of the mineral
deposit.
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- The geology and mineral distribution
of the system is reasonably complex, and is being constantly
refined as more drilling is undertaken. As such the CP has
taken a conservative approach to Mineral Resource
classification.
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- Nature of the data used and of any
assumptions made.
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- Drill hole intercept logging, assay
results and structural interpretations from drill core have formed
the basis for the geological interpretation. Assumptions have been
made on the depth and strike extents of the skarn mineralisation
interpreted at depth based on limited drilling and geophysical
information.
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- The effect, if any, of alternative
interpretations on Mineral Resource estimation.
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- The extents of the modelled zones are
generally reasonably well constrained by the geological model
interpretation which is based on the drill logging and geophysical
data. Different interpretations of the mineralisation have been
undertaken to assess the influence on Mineral Resource estimation
and hence project economics. Where geological interpretation has a
high degree of uncertainty it is classified as Inferred regardless
of modelling parameters.
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- The use of geology in guiding and
controlling Mineral Resource estimation.
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- Geology has been the primary
influence in controlling the Mineral Resource estimation.
Wireframes have been constructed for the various lithological zones
based on style of mineralisation, host rock and oxidation state as
determined by the core logging and assaying.
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- The factors affecting continuity
both of grade and geology.
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- Continuity of geology and structures
can be identified and traced between drillholes by visual,
geophysical and geochemical characteristics. Breccia zones
interpreted to relate to fault structures have been noted in the
drill core and have been modelled.
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Dimensions
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- The extent and variability of the
Mineral Resource expressed as length (along strike or otherwise),
plan width, and depth below surface to the upper and lower limits
of the Mineral Resource.
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- The South Mineralised Zone (SMZ) is
interpreted as having a 400 m strike length, is 20 to 40 m in true
width, with vertical depth up to 240 m from roughly 50 m below
surface. The North Mineralised Zone (NMZ) has a strike extent of
roughly 100 m, true width between 20 m and 60 m and depth extent of
135 m from roughly 40 m below surface.
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Estimation and
modelling techniques
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- The nature and appropriateness of
the estimation technique(s) applied and key assumptions, including
treatment of extreme grade values, domaining, interpolation
parameters and maximum distance of extrapolation from data points.
If a computer assisted estimation method was chosen include a
description of computer software and parameters
used.
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- The mineralisation has been estimated
using ordinary kriging (OK) and inverse distance to the power 2
(IDS) techniques in Datamine Studio 3 software. 30 mineralised
lenses have been interpreted and are grouped into 15 mineralised
lithological domain zones of Cu-Au-Fe mineralisation, based on lens
lithology type and grade. There are 8 of these zones in the SMZ and
7 zones in the NMZ.
The mineralised
lithological domain zones were used as hard boundaries to select
sample populations for data analysis and grade estimation. Soft
boundaries between the grouped lodes within the mineralised
lithological domain zones and hard boundaries between mineralised
lithological domain zones have been used in the grade estimation.
Statistical analysis was completed on each zone to determine
appropriate top-cuts to apply to outlier grades of Fe, Au, Cu and
Ag where required. OK was used for the majority of zones with IDS
used for 4 zones with low sample numbers.
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- The availability of check
estimates, previous estimates and/or mine production records and
whether the Mineral Resource estimate takes appropriate account of
such data.
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- For this
maiden Mineral Resource OK and IDS estimates are completed
concurrently in a number of estimation runs with varying
parameters. The results are compared against each other and the
drill hole results to ensure a reasonable estimate, that best
honours the drill sample data is reported.
No mining has yet taken place at these
deposits.
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- The assumptions made regarding
recovery of by-products.
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- Ag has been
estimated and is assumed to be also recoverable as part of the Au
recovery processes.
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- Estimation of deleterious elements
or other non-grade variables of economic significance (eg sulphur
for acid mine drainage characterisation).
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- Potentially deleterious As and S have
been estimated into the model to assist with future metallurgical
work and mining studies, but are not reported at this
stage.
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- In the case of block model
interpolation, the block size in relation to the average sample
spacing and the search employed.
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- Interpreted domains are built into a
sub-celled block model with 20m N-S by 20m E-W by 4m vertical
parent block size. Parent block size is chosen based on being
roughly half the average drill spacing over the majority of the
deposit areas. Search ellipsoids for each estimation zone have been
orientated based on their geometry and grade continuity. Sample
numbers per block estimate and ellipsoid axial search ranges have
been tailored to geometry and data density of each zone to ensure
the majority of the model is estimated within the first search
pass. The search ellipse is doubled for a second search pass and
increased 20 fold for a third search pass to ensure all blocks were
estimated. Sample numbers required per block estimate have been
reduced with each search pass.
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- Any assumptions behind modelling
of selective mining units.
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- No assumptions have been made as no
mining studies have been completed.
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- Any assumptions about correlation
between variables.
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- No assumptions have been made with
each element separately estimated. Statistical analysis shows a
generally good correlation between Au and Cu grades in unweathered
zones and poor correlation in weathered zones.
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- Description of how the geological
interpretation was used to control the resource
estimates.
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- Soft boundaries between the grouped
lodes within the mineralised lithological domain zones and hard
boundaries between mineralised lithological domain zones have been
used in the grade estimation.
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- Discussion of basis for using or
not using grade cutting or capping.
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- Statistical analysis to check grade
population distributions using histograms, probability plots and
summary statistics and the co-efficient of variation, was completed
on each zone for the estimated elements. Outlier grades were
variously found for most elements in the different mineralised
lithological domain zones and appropriate top-cuts where applied to
remove undue influence of these outlier grades on the grade
estimation for each zone.
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- The process of validation, the
checking process used, the comparison of model data to drill hole
data, and use of reconciliation data if available.
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- Validation checks included
statistical comparison between drill sample grades, the OK and IDS
estimate results for each zone. Visual validation of grade trends
for each element along the drill sections was completed and trend
plots comparing drill sample grades and model grades for northings,
eastings and elevation were completed. These checks show reasonable
correlation between estimated block grades and drill sample grades.
No reconciliation data is available as no mining has taken
place.
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Moisture
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- Whether the tonnages are estimated
on a dry basis or with natural moisture, and the method of
determination of the moisture content.
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- Tonnages have been estimated on a dry
in situ basis. No moisture values were reviewed.
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Cut-off
parameters
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- The basis of the adopted cut-off
grade(s) or quality parameters applied.
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- For some lithological units nominal
lower cut-off grades of a combination of 0.3 g/t Au and 0.3 % Cu
were used to define continuous mineralised lenses, under the
assumption that these grades would be close to a minimum economic
breakeven grade.
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Mining factors
or assumptions
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- Assumptions made regarding
possible mining methods, minimum mining dimensions and internal
(or, if applicable, external) mining dilution. It is always
necessary as part of the process of determining reasonable
prospects for eventual economic extraction to consider potential
mining methods, but the assumptions made regarding mining methods
and parameters when estimating Mineral Resources may not always be
rigorous. Where this is the case, this should be reported with an
explanation of the basis of the mining assumptions
made.
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- It has been assumed that these
deposits will be amenable to open cut mining methods, and are
economic to exploit with this methodology at the reported average
model grades. No assumptions regarding minimum mining widths and
dilution have been made to date.
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Metallurgical
factors or assumptions
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- The basis for assumptions or
predictions regarding metallurgical amenability. It is always
necessary as part of the process of determining reasonable
prospects for eventual economic extraction to consider potential
metallurgical methods, but the assumptions regarding metallurgical
treatment processes and parameters made when reporting Mineral
Resources may not always be rigorous. Where this is the case, this
should be reported with an explanation of the basis of the
metallurgical assumptions made.
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- No assumptions regarding
metallurgical amenability have been made. Metallurgical testwork is
currently being undertaken and results from this work will be
incorporated into future model updates. The oxide portions of
similar deposits in the region are being successfully exploited by
other entities, and it is assumed that these zones can be
economically exploited at the modelled grades. It is assumed that
the un-weathered mineralised material will be readily upgraded
where necessary, using standard gravity, magnetic processes and/or
froth flotation concentration techniques as appropriate for the
different product streams.
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Environmental
factors or assumptions
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- Assumptions made regarding
possible waste and process residue disposal options. It is always
necessary as part of the process of determining reasonable
prospects for eventual economic extraction to consider the
potential environmental impacts of the mining and processing
operation. While at this stage the determination of potential
environmental impacts, particularly for a greenfields project, may
not always be well advanced, the status of early consideration of
these potential environmental impacts should be reported. Where
these aspects have not been considered this should be reported with
an explanation of the environmental assumptions
made.
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- No assumptions regarding possible
waste and process residue disposal options have been made. It is
assumed that such disposal will not present a significant hurdle to
exploitation of the deposit and that any disposal and potential
environmental impacts would be correctly managed as required under
the regulatory permitting conditions.
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Bulk
density
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- Whether assumed or determined. If
assumed, the basis for the assumptions. If determined, the method
used, whether wet or dry, the frequency of the measurements, the
nature, size and representativeness of the samples.
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- In-situ dry bulk density values have
been applied to the modelled mineralisation based on linear
regression formulas for weathered and unweathered material
separately. This is based on reasonable correlations having been
found between measured bulk density results and Fe. Of the 674
measurements taken, 435 have assay result data, with 177 falling
within the interpreted mineralised zones.
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- The bulk density for bulk material
must have been measured by methods that adequately account for void
spaces (vugs, porosity, etc), moisture and differences between rock
and alteration zones within the deposit.
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- Density measurements have been taken
on drill samples using wax coated water displacement methods, from
all different lithological types.
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- Discuss assumptions for bulk
density estimates used in the evaluation process of the different
materials.
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- With the reasonable correlation
between Fe grade and bulk density, it is assumed that use of the
regression formulas describing this relationship is an appropriate
method of representing the expected variability in bulk density for
the grade estimated mineralised blocks.
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Classification
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- The basis for the classification
of the Mineral Resources into varying confidence
categories.
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- Classification of the Mineral
Resource estimates was carried out taking into account the level of
geological understanding of the deposit, quality of samples,
density data and drill hole spacing.
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- Whether appropriate account has
been taken of all relevant factors (ie relative confidence in
tonnage/grade estimations, reliability of input data, confidence in
continuity of geology and metal values, quality, quantity and
distribution of the data).
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- The classification reflects areas of
lower and higher geological confidence in mineralised lithological
domain continuity based the intersecting drill sample data numbers,
spacing and orientation. Overall mineralisation trends are
reasonably consistent within the various lithotypes over numerous
drill sections.
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- Whether the result appropriately
reflects the Competent Person's view of the
deposit.
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- The Mineral Resource estimate
appropriately reflects the view of the Competent
Person.
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Audits or
reviews
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- The results of any audits or
reviews of Mineral Resource estimates.
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- Internal audits were completed by CSA
Global which verified the technical inputs, methodology, parameters
and results of the estimate.
No external audits have been undertaken.
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Discussion of
relative accuracy/ confidence
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- Where appropriate a statement of
the relative accuracy and confidence level in the Mineral Resource
estimate using an approach or procedure deemed appropriate by the
Competent Person. For example, the application of statistical or
geostatistical procedures to quantify the relative accuracy of the
resource within stated confidence limits, or, if such an approach
is not deemed appropriate, a qualitative discussion of the factors
that could affect the relative accuracy and confidence of the
estimate.
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- The relative accuracy of the Mineral
Resource estimate is reflected in the reporting of the Mineral
Resource as per the guidelines of the 2012 JORC Code.
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- The statement should specify
whether it relates to global or local estimates, and, if local,
state the relevant tonnages, which should be relevant to technical
and economic evaluation. Documentation should include assumptions
made and the procedures used.
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- The Mineral Resource statement
relates to global estimates of in-situ tonnes and
grade.
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- These statements of relative
accuracy and confidence of the estimate should be compared with
production data, where available.
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- The deposit has not, and is not
currently being mined.
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