Bluebird-South
Junction expands to 1.2Mtpa run rate from Q3 FY25
PERTH,
Australia and TORONTO, Aug. 16,
2024 /CNW/ - Westgold Resources Limited (ASX:
WGX) (TSX: WGX) (OTCQX: WGXRF) – Westgold or the
Company) is pleased to present the maiden Ore Reserve for
its South Junction mine.
South Junction is a part of a
broader Bluebird - South Junction
mining complex which is becoming the primary ore source for the
Bluebird processing hub at Meekatharra with a 1.2Mtpa run rate
targeted from Q3, FY25.
Highlights
Bluebird – South Junction Ore Reserve increases to 3.0Mt @
2.8g/t Au for 277koz
- 233% increase (+158koz) from the FY23 Ore Reserve post
depletion.
- Contribution from the maiden South Junction Ore Reserve
of 2.6Mt @ 2.7g/t Au for 225koz.
Updated Bluebird – South Junction Mineral Resource exceeds
Interim Mineral Resource announced in March
2024 by a further 130koz post depletion of 14koz
- 61% increase in Indicated Resources.
- Ore Reserve underwritten by updated Mineral Resource Estimate
(MRE) of 11Mt @ 2.8g/t Au for 960koz featuring a Measured
and Indicated component of 4.7Mt @ 3.1g/t Au for 465koz Au.
Further Resource conversion targeted with substantial
drilling program ongoing
- 2 x surface rigs and 2 x underground drill rigs continue to
extend and infill the Bluebird – South Junction Mineral
Resource.
- South Junction remains open at
depth and to the south along strike/down plunge.
Production from South
Junction to commence in August
- The significant width of the South
Junction orebody enables a highly productive primary /
secondary transverse stoping method which will significantly
increase production from the Bluebird – South Junction system.
- Production rate of 1.2Mtpa – from Bluebird-South
Junction targeted from Q3 FY25.
Westgold Managing Director and CEO Wayne Bramwell commented:
"Westgold is rapidly building a mine of significant scale and
life at Meekatharra. The maiden Ore Reserve for South Junction and the rapid expansion of the
Bluebird-South Junction mining complex to a 1.2Mtpa run rate by Q3,
FY25 has been a remarkable success story and underpins the value in
drilling.
A larger, more productive Bluebird-South Junction underground
mine is a game changer for our Murchison business. It will reduce
the requirement and cost of road haulage of ore from Cue (circa
140km) as the Bluebird-South Junction complex is within 2km of the
nearby Bluebird mill.
Westgold will continue to invest in drilling across our
portfolio in FY25. With Bluebird-South Junction and Big Bell in the
Murchison, buttressed by the expanding Beta Hunt in the Goldfields,
we continue to build a diversified platform that can produce more
consistent and sustainable long term cashflows and returns to our
shareholders."
South Junction – production
online in August, due to lift rates from Q3 FY25
Westgold's pipeline of organic growth targets is extensive.
South Junction at Meekatharra was
identified as a priority growth opportunity following the results
of initial drill testing of the project in early 20231.
A significant drilling program was initiated in January 2024 aimed at extending
and infilling South Junction.
This program continues, with two rigs active on surface and two in
the underground environment.
Westgold recognised the vast scale of South Junction, prompting the undertaking of
an interim MRE2 to expedite mine planning studies.
Since March, drilling to increase the confidence in the Inferred
portion of the MRE has progressed in parallel with mine planning
studies. The results of this drilling have enabled Westgold to
undertake an update to the MRE that has seen the substantial
conversion of Inferred material to Indicated (See Table 1 and
Figure 2). This update includes 14koz of depletion from three
months of production on the Bluebird side of the mine.
Classification
|
Interim March 2024
MRE
|
August 2024
MRE
|
Tonnes
|
Grade
(g/t
Au)
|
Ounces
|
Tonnes
|
Grade
(g/t Au)
|
Ounces
|
Measured
|
302,000
|
4.4
|
43,000
|
304,000
|
4.1
|
40,000
|
Indicated
|
2,872,000
|
2.9
|
264,000
|
4,368,000
|
3.0
|
425,000
|
Inferred
|
5,844,000
|
2.8
|
520,000
|
6,032,000
|
2.6
|
495,000
|
Total
|
9,017,000
|
2.9
|
827,000
|
10,705,000
|
2.8
|
960,000
|
Table 1 – Bluebird - South Junction MRE August 2024 (reported above 1.5g/t
Au)3
____________________________
|
1
|
Refer ASX Release
titled "Bluebird Expansion and Drilling Update - 11 January
2023"
|
2
|
Refer ASX Release
entitled "Bluebird-South Junction Increases to 6.4Mt at 3.1 g/t Au-
16 April 2023"
|
3
|
Interim March 2024 MRE
as at 31 March 2024 and August 2024 MRE as at 30 June
2024
|
Subsequent mine planning and commercial evaluation works have
resulted in an updated Ore Reserve being declared for the Bluebird
– South Junction mine (Table 2).
The contribution to this overall Ore Reserve from the Maiden South
Junction Ore Reserve subset is presented in Table 3.
Classification
|
Tonnes
|
Grade
(g/t
Au)
|
Ounces
|
Proven
|
76,600
|
3.9
|
9,400
|
Probable
|
2,966,500
|
2.8
|
268,000
|
Total
|
3,041,000
|
2.8
|
277,000
|
Table 2 – Bluebird - South Junction Ore Reserve August 2024
Classification
|
Tonnes
|
Grade
(g/t
Au)
|
Ounces
|
Proven
|
26,300
|
3.1
|
2,600
|
Probable
|
2,612,000
|
2.7
|
223,000
|
Total
|
2,638,000
|
2.7
|
226,000
|
Table 3 –South Junction Maiden Ore Reserve August 2024
Background to the Ore Reserve Estimation
The South Junction Ore Reserve was estimated using Deswik Shape
Optimiser (DSO). These were run against gradient strings reflective
of the potential location for ore drives. The settings used as part
of the DSO run were as follows:
Parameter
|
Value
|
Optimisation
Field
|
res_au
|
Slice Method
|
YZ
|
Pillar Between
Stopes
|
0m
|
Stope Length
|
5m
|
Minimum Mining
Width
|
1.2m
|
Table 4 – DSO Factors
Level spacing was mixed and dependent on the gradient strings.
As Bluebird and South Junction
orebodies have different geometric characteristics, the level
spacing within the two will differ. Dilution "skins" were not
applied to the DSO shapes and instead was completed during the
scheduling stage as these can be continually revised and adjusted
during the mining phase. Although the minimum mining length during
the DSO run was set to 5m, it was
determined that the minimum "mineable" stope length is 10m. This was based off the operational
likelihood on mining parameters. Stopes were then created by
connecting the 5m shapes into larger
stopes based on the geotechnical parameters. Due to the width of
the orebody, a highly productive primary / secondary transverse
stoping method with fill will be employed at South Junction. This change in method will
enable the production rates of Bluebird – South Junction to increase to more than triple
from the current rate of +30kt per month (refer ASX – Westgold
March 2024 Quarterly Report) to rates
of 100kt per month from Q3 FY25.
Westgold has taken a conservative approach to stope geometry
values by keeping the primary and secondary stope lengths
consistent at 17.5m each with the
potential to adjust once mining begins.
Parameter
|
Value
|
Minimum stope size
length
|
10m
|
Maximum stope length
(primary)
|
17.5m
|
Maximum stope length
(secondary)
|
17.5m
|
Table 5 – Final mining parameters
Modifying factors have been applied to the South Junction Ore
Reserve stope shapes that best reflect the transverse methodology.
These have been built from a first principles basis based on
geotechnical recommendations alongside orebody dimensions and
geometry.
Parameter
|
Value
|
Comments
|
Mine Operating
COG
|
2.1g/t
|
Assumes development
complete
|
Full Costed
COG
|
2.3g/t
|
Incorporates initial
and sustaining capital
|
Stope
Recovery
|
90 %
|
Estimated based on size
and dip
|
Stope
Dilution
|
10 %
|
Calculated based on
geotechnical parameters
|
Development
COG
|
1.0gt
|
Non-mining costs,
assuming material hauled to surface
|
Table 6 – Modifying factors used for South Junction Ore
Reserve
Cut-off grades (COG) are based on realised cost profiles
determined from the adjacent Bluebird mine and based on a gold
price of $3,000AUD/oz. They have been
adjusted to reflect the change in mining method employed at
South Junction.
Processing recoveries used within the mine plan are indicative
of those achieved at the Bluebird plant currently. As Bluebird is
an operating mine, environmental, and other governmental approvals
are currently in place.
Mining in South Junction is
scheduled to commence in August
Production rates at South
Junction will rapidly increase over the coming months. This
ramp up is a function of the increased scale of the South Junction lodes (as compared to the
Bluebird lodes) which accommodates a more productive mine layout
and extraction sequence. (see Figure 4 which depicts the vast
difference in scale compared a typical Bluebird stope)
Background to the Mineral Resource Estimation
The Yaloginda area which hosts Bluebird – South Junction, is a gold-bearing Archaean
greenstone belt situated ~15km south of Meekatharra. The deposits
in the area are hosted in a strained and metamorphosed volcanic
sequence that consists primarily of ultramafic and high-magnesium
basalt with minor komatiite, peridotite, gabbro, tholeiitic basalt
and interflow sediments. This sequence was intruded by a variety of
felsic porphyry and intermediate sills and dykes.
South Junction is comprised of
numerous mineralised zones broadly located on sub-parallel
north-northeast-trending structures. These zones from west to east
are: Edin Hope, South Junction, Polar Star and Archenar. These
zones are offset to the south from the East, Central and Western
lodes at Bluebird. Mining in the Murchison district has occurred
since 1800's providing significant confidence in the currently
geological interpretation of the project.
Geological interpretation of the deposit was carried out using a
systematic approach to ensure that the resultant estimated Mineral
Resource figure was both sufficiently constrained, and
representative of the expected sub-surface conditions. In all
aspects of Mineral Resource Estimation, the factual and interpreted
geology was used to guide the development of the interpretation.
Geological matrixes were established to assist with interpretation
and construction of the estimation domains. The structural regime
is the dominant control on geological and grade continuity in the
Murchison. Lithological factors such as rheology contrast are
secondary controls on grade distribution.
Bluebird – South Junction is
mineralised a strike length of >1,800m, a lateral extent of up +50m and a depth of over 500m.
A significant portion of the data used in resource calculations
has been gathered from diamond core. Multiple sizes have been used.
This core is geologically logged and subsequently halved for
sampling. Grade control holes may be whole-cored to streamline the
core handling process if required. Face sampling data is also
utilised, where each development face / round is horizontally chip
sampled. The sampling intervals are domained by geological
constraints (e.g. rock type, veining and alteration / sulphidation
etc.).
All geology input is logged and validated by the relevant area
geologists, incorporated into this is assessment of sample
recovery. No defined relationship exists between sample recovery
and grade, nor has sample bias due to preferential loss or gain of
fine or coarse material been noted.
Sampling is analysed by fire assay as outlined below;
- A representative 40g – 50g sample undergoes fire assay lead
collection followed by flame atomic adsorption spectrometry.
- Quality control is ensured via the use of standards, blanks and
duplicates. The laboratory includes a minimum of 1 project standard
with every 22 samples analysed. No significant QA/QC issues have
arisen in recent drilling results.
After validating the drillhole data to be used in the
estimation, interpretation of the mineralsiation is undertaken in
sectional and / or plan view to create the outline strings which
form the basis of the three-dimensional orebody wireframe.
Wireframing is then carried out using a combination of automated
stitching algorithms and manual triangulation to create an accurate
three-dimensional representation of the sub-surface mineralised
body.
Drillhole intersections within the mineralised body are defined,
these intersections are then used to flag the appropriate sections
of the drillhole database tables for compositing purposes.
Drillholes are subsequently composited to allow for grade
estimation. In all aspects of resource estimation, the factual and
interpreted geology was used to guide the development of the
interpretation.
Once the sample data has been composited, a statistical analysis
is undertaken to assist with determining estimation search
parameters, top-cuts etc. Analysis of individual domains is
undertaken to assist with determining appropriate search
parameters. Which are then incorporated with observed geological
and geometrical features to determine the most appropriate search
parameters.
An empty block model is then created for the area of interest.
This model contains attributes set at background values for the
various elements of interest as well as density, and various
estimation parameters that are subsequently used to assist in
resource categorisation. The block sizes used in the model will
vary depending on orebody geometry, minimum mining units,
estimation parameters and levels of informing data available.
Grade estimation is then undertaken. Ordinary kriging estimation
method is considered as standard, although in some circumstances
where sample populations are small, or domains are unable to be
adequately defined, inverse distance weighting estimation
techniques will be used. For very minor lodes, the respective
median or average grade is assigned. In these circumstances lodes
are subsequently classified in lower Mineral Resource confidence
categories as appropriate.
Estimation results are validated against primary input data,
previous estimates and mining output.
The Mineral Resource is then depleted for mining voids and
subsequently classified in line with JORC guidelines utilising a
combination of various estimation derived parameters and geological
/ mining knowledge.
Data spacing is variable dependent upon the individual lode
under consideration. At Bluebird – South Junction Measured
Resources are supported by average drillhole spacing in the range
of 15-35m, Indicated from
10-180m and Inferred from
10-200m.
This approach considers all relevant factors and reflects the
Competent Person's view of the deposit.
The cut off grades used for the reporting of the Mineral
Resources have been selected based on the style of mineralisation,
depth from surface of the mineralisation and the most probable
extraction technique and associated costs. At Bluebird –
South Junction this has been
determined to be 1.5g/t Au.
Likely mining approaches have been considered at the domaining,
estimation and classification steps. However, no mining dilution or
ore loss has been modelled in the resource model or applied to the
reported Mineral Resource. Nor has metallurgical recovery been
applied to the reported Mineral Resource. These factors are applied
during the Ore Reserve generation process.
Looking Forward
Westgold's corporate strategy is to continue to simplify our
business by making our biggest mines bigger and focusing on grade.
The expansion of the Bluebird underground to include new mining
fronts from South Junction is
consistent with this plan.
Drilling activities continue to expand the Bluebird –
South Junction system and increase
Mineral Resource confidence. This continued drilling will
ultimately underwrite future updates to the MRE and Ore Reserve.
The orebody remains open at depth and to the south along
strike/down plunge, as can be seen in Figure
1.
Necessary capital projects to enable the larger mine to function
effectively are progressively being scoped and delivered, with
power, ventilation and backfill solutions well defined. Westgold
looks forward to providing updates on its progress at Bluebird –
South Junction over the coming
months.
This announcement is authorised for release to the ASX
by the Board.
Competent/Qualified Person Statements
Exploration Results and Mineral Resource Estimates
The information in this release that relates to Exploration
results and Mineral Resource Estimates is compiled by Westgold
technical employees and contractors under the supervision of Mr.
Jake Russell B.Sc. (Hons), who is a
member of the Australian Institute of Geoscientists and who has
verified, reviewed and approved such information. Mr Russell is a
full-time employee of the Company and has sufficient experience
which is relevant to the styles of mineralisation and types of
deposit under consideration and to the activities which he is
undertaking to qualify as a Competent Person as defined in the 2012
Edition of the Australasian Code for Reporting of Exploration
Results, Mineral Resources and Ore Reserves (the "JORC
Code") and as a Qualified Person as defined in the CIM
Guidelines and National Instrument 43-101 – Standards of
Disclosure for Mineral Projects ("NI 43-101"). Mr.
Russell is an employee of the Company and, accordingly, is not
independent for purposes of NI 43-101. Mr Russell consents to and
approves the inclusion in this release of the matters based on his
information in the form and context in which it appears. Mr Russell
is eligible to participate in short- and long-term incentive plans
of the company.
The updated MRE has an effective date of 30 June 2024 and was completed by Westgold
technical employees and contractors under the supervision of Mr
Jake Russell. The key inputs and
assumptions are provided in Appendix C to this release including
Section 1 – Sampling Techniques and Data, Section 2 – Reporting of
Exploration Results, Section 3 – Estimation and Reporting of
Mineral Resources and Section 4 – Estimation and Reporting of Ore
Reserves.
Ore Reserves
The information in this release that relates to Ore Reserve is
based on information compiled by Mr. Leigh
Devlin B.Eng. FAusIMM, who has verified, reviewed and
approved such information. Mr. Devlin has sufficient experience
which is relevant to the styles of mineralisation and types of
deposit under consideration and to the activities which they are
undertaking to qualify as a Competent Person as defined in the JORC
Code and as a Qualified Person as defined in the CIM Guidelines and
NI 43-101. Mr. Devlin is an employee of the Company and,
accordingly, is not independent for purposes of NI 43-101. Mr.
Devlin consents to and approves the inclusion in this release of
the matters based on his information in the form and context in
which it appears. Mr. Devlin is a full-time senior executive of the
Company and is eligible to and may participate in short-term and
long-term incentive plans of the Company as disclosed in its annual
reports and disclosure documents.
General
Mineral Resources, Ore Reserve Estimates and Exploration Targets
and Results are calculated in accordance with the JORC Code. The
other technical and scientific information in this release has been
prepared in accordance with the Canadian regulatory requirements
set out in NI 43-101 and has been reviewed on behalf of the company
by Qualified Persons, as set forth above.
This release contains references to estimates of Mineral
Resources and Ore Reserves. The estimation of Mineral Resources is
inherently uncertain and involves subjective judgments about many
relevant factors. Mineral Resources that are not Ore Reserves do
not have demonstrated economic viability. The accuracy of any such
estimates is a function of the quantity and quality of available
data, and of the assumptions made and judgments used in engineering
and geological interpretation, which may prove to be unreliable and
depend, to a certain extent, upon the analysis of drilling results
and statistical inferences that may ultimately prove to be
inaccurate. Mineral Resource estimates may require re-estimation
based on, among other things: (i) fluctuations in the price of
gold; (ii) results of drilling; (iii) results of metallurgical
testing, process and other studies; (iv) changes to proposed mine
plans; (v) the evaluation of mine plans subsequent to the date of
any estimates; and (vi) the possible failure to receive required
permits, approvals and licenses.
The NI 43-101 technical report supporting the Maiden Ore Reserve
contained in this release will be filed on SEDAR+ within the next
45 days of the date of this release. Reference should be made to
the full text of the technical report for the assumptions,
qualifications and limitations relating thereto.
Forward looking statements
These materials prepared by Westgold Resources Limited include
forward looking statements. Often, but not always, forward looking
statements can generally be identified by the use of forward
looking words such as "may", "will", "expect", "intend", "believe",
"forecast", "predict", "plan", "estimate", "anticipate",
"continue", and "guidance", or other similar words and may include,
without limitation, statements regarding plans, strategies and
objectives of management, anticipated production or construction
commencement dates and expected costs or production outputs.
Forward looking statements inherently involve known and unknown
risks, uncertainties and other factors that may cause the Company's
actual results, performance and achievements to differ materially
from any future results, performance or achievements. Relevant
factors may include, but are not limited to, changes in commodity
prices, foreign exchange fluctuations and general economic
conditions, increased costs and demand for production inputs, the
speculative nature of exploration and project development,
including the risks of obtaining necessary licenses and permits and
diminishing quantities or grades of reserves, political and social
risks, changes to the regulatory framework within which the Company
operates or may in the future operate, environmental conditions
including extreme weather conditions, recruitment and retention of
personnel, industrial relations issues and litigation.
Forward looking statements are based on the Company and its
management's good faith assumptions relating to the financial,
market, regulatory and other relevant environments that will exist
and affect the Company's business and operations in the future. The
Company does not give any assurance that the assumptions on which
forward looking statements are based will prove to be correct, or
that the Company's business or operations will not be affected in
any material manner by these or other factors not foreseen or
foreseeable by the Company or management or beyond the Company's
control.
Although the Company attempts and has attempted to identify
factors that would cause actual actions, events or results to
differ materially from those disclosed in forward looking
statements, there may be other factors that could cause actual
results, performance, achievements or events not to be as
anticipated, estimated or intended, and many events are beyond the
reasonable control of the Company. In addition, the Company's
actual results could differ materially from those anticipated in
these forward looking statements as a result of the factors
outlined in the "Risk Factors" section of the Company's continuous
disclosure filings available on SEDAR+ or the ASX, including, in
the Company's current annual report, half year report or most
recent management discussion and analysis.
Accordingly, readers are cautioned not to place undue reliance
on forward looking statements. Forward looking statements in these
materials speak only at the date of issue. Subject to any
continuing obligations under applicable law or any relevant stock
exchange listing rules, in providing this information the Company
does not undertake any obligation to publicly update or revise any
of the forward-looking statements or to advise of any change in
events, conditions or circumstances.
Appendix A
History of South
Junction
Mineralisation was discovered at South
Junction in mid-1989 by St Barbara Mining. South Junction was subsequently mined as an
open pit from June 1990 through to
the early 2000's. Total gold production for the open pit phase of
operation at South Junction was in
excess of 400,000 ounces. However, since open pit mining concluded
activity at South Junction has
effectively been dormant.
To the immediate north of South
Junction, the Bluebird deposit has been mined at various
stages. This mining was dominated by small scale underground mining
operations and open pits until the turn of the century after which
St Barbara, Mercator Gold and Reed Resources mined 485,000 ounces
between 2000 – 2013 via substantial open pit operations.
In late 2019, Westgold commenced underground operations at
Bluebird which subsequently produced over 137koz of gold. This
brings the total recorded Bluebird production to 784koz and the
combined Bluebird – South Junction
production to 1.18Moz. Combining this with the Mineral Resource
remaining, Bluebird – South
Junction can be considered a +2Moz system.
Murchison Overview
Westgold's Murchison Operations incorporates four underground
mines, three processing plants and the Great Fingall development
project near Cue. Westgold's Bluebird processing hub is the largest
of our three Murchison processing hubs and is located approximately
15km southwest of Meekatharra (see Figure 7).
The Bluebird underground mine is the primary ore source feeding
the 1.4-1.8Mtpa Bluebird processing plant. Surface stockpiles and
supplementary ore from Cue is trucked to Bluebird to maintain
processing throughputs, with these volumes reducing as the
Bluebird-South Junction mine expands.
APPENDIX B – Drill Results Included In This
Release4
Hole
|
Collar N
|
Collar E
|
Collar RL
|
Intercept (Downhole)
|
From (m)
|
Dip
|
Azi
|
24BLDD064
|
7,043,673
|
641,491
|
100
|
3.07m at 2.30g/t
Au
|
15
|
-47
|
101
|
1m at 6.37g/t
Au
|
41
|
31.37m at 5.55g/t
Au
|
122
|
15.5m at 4.62g/t
Au
|
158
|
24BLDD066
|
7,043,673
|
641,491
|
100
|
4.6m at 3.79g/t
Au
|
21
|
-53
|
113
|
22.8m at 1.25g/t
Au
|
173
|
15.82m at 3.09g/t
Au
|
210
|
18.9m at 3.65g/t
Au
|
293
|
24BLDD095
|
7,043,757
|
641,489
|
96
|
9.25m at 3.79g/t
Au
|
122
|
-22
|
67
|
24SJDD001
|
7043454
|
641917
|
468
|
10.45m at 3.80g/t
Au
|
788
|
-79
|
302
|
3.98m at 10.80g/t
Au
|
894.49
|
24SJDD004
|
7043417
|
641924
|
468
|
3.75m at 3.01g/t
Au
|
560
|
-48
|
292
|
9.45m at 2.54g/t
Au
|
573.85
|
3.29m at 3.28g/t
Au
|
588.53
|
24SJDD010
|
7043417
|
641925
|
467
|
12.70m at 8.57g/t
Au
|
415.58
|
-53
|
296
|
8.03m at 1.58g/t
Au
|
543.44
|
4.00m at 3.81g/t
Au
|
637
|
24SJDD012
|
7043411
|
641923
|
467
|
2.00m at 6.72g/t
Au
|
418
|
-52
|
296
|
7.90m at 5.20g/t
Au
|
592.5
|
6.80m at 3.87g/t
Au
|
600.9
|
3.68m at 4.55g/t
Au
|
619.87
|
24SJDD015
|
7043411
|
641923
|
467
|
3.00m at 4.54g/t
Au
|
482
|
-59
|
293
|
3.00m at 12.91g/t
Au
|
531.7
|
|
8.10m at 4.31g/t
Au
|
656
|
2.21m at 17.30g/t
Au
|
696.79
|
24SJDD019_W1
|
7043410
|
641925
|
467
|
6.27m at 3.76g/t
Au
|
641.42
|
-59
|
284
|
2.62m at 4.26g/t
Au
|
648.53
|
24SJDD021_W2
|
7043405
|
641939
|
467
|
5.79m at 2.39g/t
Au
|
541.71
|
-65
|
294
|
4.70m at 4.58g/t
Au
|
550.3
|
20.94m at 6.74g/t
Au
|
681.86
|
INC 4.68m at 16.48g/t
Au
|
687
|
____________________________________
|
4
|
Refer to Westgold's Q2
FY24, Q3 FY24 and Q4 FY24 Quarterly Reports on ASX for full South
Junction drill results
|
APPENDIX C – JORC 2012 TABLE 1 – GOLD DIVISION
SECTION 1: SAMPLING TECHNIQUES AND DATA
(Criteria in this section apply to all succeeding sections.)
Criteria
|
JORC Code
Explanation
|
Commentary
|
Sampling
techniques
|
- Nature and quality
of sampling (e.g. cut channels, random chips, or specific
specialised industry standard measurement tools appropriate to the
minerals under investigation, such as down hole gamma sondes, or
handheld XRF instruments, etc.). These examples should not be taken
as limiting the broad meaning of sampling.
- Include reference
to measures taken to ensure sample representivity and the
appropriate calibration of any measurement tools or systems
used.
- Aspects of the
determination of mineralisation that are Material to the Public
Report.
- In cases where
'industry standard' work has been done this would be relatively
simple (e.g. 'reverse circulation drilling was used to obtain 1 m
samples from which 3 kg was pulverised to produce a 30 g charge for
fire assay'). In other cases more explanation may be required, such
as where there is coarse gold that has inherent sampling problems.
Unusual commodities or mineralisation types (e.g. submarine
nodules) may warrant disclosure of detailed
information.
|
- Diamond
Drilling
A significant portion
of the data used in resource calculations has been gathered from
diamond core. Multiple sizes have been used historically. This core
is geologically logged and subsequently halved for sampling. Grade
control holes may be whole-cored to streamline the core handling
process if required.
- Face
Sampling
At each of the major
past and current underground producers, each development face /
round is horizontally chip sampled. The sampling intervals are
domained by geological constraints (e.g. rock type, veining and
alteration / sulphidation etc.). The majority of exposures within
the orebody are sampled.
|
Drilling
techniques
|
- Drill type (e.g.
core, reverse circulation, open-hole hammer, rotary air blast,
auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple
or standard tube, depth of diamond tails, face-sampling bit or
other type, whether core is oriented and if so, by what method,
etc.).
|
- Sludge
Drilling
Sludge drilling at is
performed with an underground production drill rig. It is an open
hole drilling method using water as the flushing medium, with a
64mm (nominal) hole diameter. Sample intervals are ostensibly the
length of the drill steel. Holes are drilled at sufficient angles
to allow flushing of the hole with water following each interval to
prevent contamination. Sludge drilling is not used to inform
resource models.
- RC
Drilling
Drill cuttings are
extracted from the RC return via cyclone. The underflow from each
interval is transferred via bucket to a four-tiered riffle
splitter, delivering approximately three kilograms of the recovered
material into calico bags for analysis. The residual material is
retained on the ground near the hole. Composite samples are
obtained from the residue material for initial analysis, with the
split samples remaining with the individual residual piles until
required for re-split analysis or eventual disposal.
- RAB / Aircore
Drilling
Combined scoops from
bucket dumps from cyclone for composite. Split samples taken from
individual bucket dumps via scoop. RAB holes are not included in
the resource estimate.
- Blast Hole
Drilling
Cuttings sampled via
splitter tray per individual drill rod. Blast holes not included in
the resource estimate.
|
Drill sample
recovery
|
- Method of recording
and assessing core and chip sample recoveries and results
assessed.
- Measures taken to maximise sample recovery and ensure representative nature of
the samples.
- Whether a relationship exists between sample
recovery and grade and whether sample bias may have occurred due to
preferential loss/gain of fine/coarse material.
|
All geology input is
logged and validated by the relevant area geologists, incorporated
into this is assessment of sample recovery. No defined relationship
exists between sample recovery and grade. Nor has sample bias due
to preferential loss or gain of fine or coarse material been
noted.
|
Logging
|
- Whether core and
chip samples have been geologically and geotechnically logged to a
level of detail to support appropriate Mineral Resource estimation,
mining studies and metallurgical studies.
- Whether logging is
qualitative or quantitative in nature. Core (or costean, channel,
etc.) photography.
- The total length
and percentage of the relevant intersections logged
|
- Westgold surface
drill-holes are all orientated and have been logged in detail for
geology, veining, alteration, mineralisation and orientated
structure. Westgold underground drill-holes are logged in detail
for geology, veining, alteration, mineralisation and structure.
Core has been logged in enough detail to allow for the relevant
mineral resource estimation techniques to be employed.
- Surface core is
photographed both wet and dry and underground core is photographed
wet. All photos are stored on the Company's servers, with the
photographs from each hole contained within separate
folders.
- Development faces
are mapped geologically.
- RC, RAB and Aircore
chips are geologically logged.
- Sludge drilling is
logged for lithology, mineralisation and vein
percentage.
- Logging is both
qualitative and quantitative in nature.
- All holes are
logged completely, all faces are mapped completely.
|
Sub-sampling
techniques and sample preparation
|
- If core, whether
cut or sawn and whether quarter, half or all core
taken.
- If non-core,
whether riffled, tube sampled, rotary split, etc. and whether
sampled wet or dry.
- For all sample
types, the nature, quality and appropriateness of the sample
preparation technique.
- Quality control
procedures adopted for all sub-sampling stages to maximise
representivity of samples.
- Measures taken to
ensure that the sampling is representative of the in-situ material
collected, including for instance results for field
duplicate/second-half sampling.
- Whether sample
sizes are appropriate to the grain size of the material being
sampled.
|
- Blast holes
-Sampled via splitter tray per individual drill rods.
- RAB / AC chips -
Combined scoops from bucket dumps from cyclone for composite. Split
samples taken from individual bucket dumps via scoop.
- RC - Three tier
riffle splitter (approximately 5kg sample). Samples generally
dry.
- Face Chips -
Nominally chipped horizontally across the face from left to right,
sub-set via geological features as appropriate.
- Diamond Drilling -
Half-core niche samples, sub-set via geological features as
appropriate. Grade control holes may be whole-cored to streamline
the core handling process if required.
- Chips / core chips
undergo total preparation.
- Samples undergo
fine pulverisation of the entire sample by an LM5 type mill to
achieve a 75µ product prior to splitting.
- QA/QC is currently
ensured during the sub-sampling stages process via the use of the
systems of an independent NATA / ISO accredited laboratory
contractor. A significant portion of the historical informing data
has been processed by in-house laboratories.
- The sample size is
considered appropriate for the grain size of the material being
sampled.
- The un-sampled half
of diamond core is retained for check sampling if required. For RC
chips regular field duplicates are collected and analysed for
significant variance to primary results.
|
Quality of assay
data and laboratory tests
|
- The nature, quality
and appropriateness of the assaying and laboratory procedures used
and whether the technique is considered partial or
total.
- For geophysical
tools, spectrometers, handheld XRF instruments, etc., the
parameters used in determining the analysis including instrument
make and model, reading times, calibrations factors applied and
their derivation, etc.
- Nature of quality
control procedures adopted (e.g. standards, blanks, duplicates,
external laboratory checks) and whether acceptable levels of
accuracy (i.e. lack of bias) and precision have been
established.
|
- Recent sampling was
analysed by fire assay as outlined below;
-
- A 40g – 50g sample
undergoes fire assay lead collection followed by flame atomic
adsorption spectrometry.
- The laboratory
includes a minimum of 1 project standard with every 22 samples
analysed.
- Quality control is
ensured via the use of standards, blanks and
duplicates.
- No significant
QA/QC issues have arisen in recent drilling results.
- Photon Assay was
introduced in 2023 for Beta Hunt grade control samples.
PhotonAssay™ technology (Chrysos Corporation Limited) is a rapid,
non-destructive analysis of gold and other elements in mineral
samples. It is based on the principle of gamma activation, which
uses high energy x-rays to excite changes to the nuclear structure
of selected elements. The decay is then measured to give a gold
analysis. Each sample is run through two cycles with a radiation
time of 15s. This methodology is insensitive to material type and
thus does not require fluxing chemicals as in the fire assay
methodology. Highlights of the PhotonAssay™ process are as
follows:
-
- The process is
non-destructive; the same sample accuracy can be determined by
repeat measurements of the same sample. In addition, the instrument
runs a precision analysis for each sample relating to the
instrument precision
- The process allows
for an increased sample size, about 500 g of crushed
product.
- The crushed
material is not pulverised, as in the fire assay process; this
ensures that gold is not smeared or lost during pulverisation
(especially important if there is an expectation of visible gold
that is being analysed)
- Historical drilling
has used a combination of Fire Assay, Aqua Regia and PAL
analysis.
- These assay
methodologies are appropriate for the resources in
question.
|
Verification of
sampling and assaying
|
- The verification of
significant intersections by either independent or alternative
company personnel.
- The use of twinned
holes.
- Documentation of
primary data, data entry procedures, data verification, data
storage (physical and electronic) protocols.
- Discuss any
adjustment to assay data.
|
- No independent or
alternative verifications are available.
- Virtual twinned
holes have been drilled in several instances across all sites with
no significant issues highlighted. Drillhole data is also routinely
confirmed by development assay data in the operating
environment.
- Primary data is
collected utilising LogChief. The information is imported into a
SQL database server and verified.
- All data used in
the calculation of resources and reserves are compiled in databases
(underground and open pit) which are overseen and validated by
senior geologists.
- No adjustments have
been made to any assay data.
|
Location of data
points
|
- Accuracy and
quality of surveys used to locate drill holes (collar and down-hole
surveys), trenches, mine workings and other locations used in
Mineral Resource estimation.
- Specification of
the grid system used.
- Quality and
adequacy of topographic control.
|
- All data is
spatially oriented by survey controls via direct pickups by the
survey department. Drillholes are all surveyed downhole, deeper
holes with a Gyro tool if required, the majority with single /
multishot cameras.
- All drilling and
resource estimation is preferentially undertaken in local mine grid
at the various sites.
- Topographic control
is generated from a combination of remote sensing methods and
ground-based surveys. This methodology is adequate for the
resources in question.
|
Data spacing and
distribution
|
- Data spacing for
reporting of Exploration Results.
- Whether the data
spacing and distribution is sufficient to establish the degree of
geological and grade continuity appropriate for the Mineral
Resource and Ore Reserve estimation procedure(s) and
classifications applied.
- Whether sample
compositing has been applied.
|
- Data spacing is
variable dependent upon the individual orebody under consideration.
A lengthy history of mining has shown that this approach is
appropriate for the Mineral Resource Estimation process and to
allow for classification of the resources as they
stand.
- Compositing is
carried out based upon the modal sample length of each individual
domain.
|
Orientation of data
in relation to geological structure
|
- Whether the
orientation of sampling achieves unbiased sampling of possible
structures and the extent to which this is known, considering the
deposit type.
- If the relationship
between the drilling orientation and the orientation of key
mineralised structures is considered to have introduced a sampling
bias, this should be assessed and reported if material.
|
- Drilling
intersections are nominally designed to be normal to the orebody as
far as underground infrastructure constraints / topography
allows.
- Development
sampling is nominally undertaken normal to the various
orebodies.
- Where drilling
angles are sub optimal the number of samples per drill hole used in
the estimation has been limited to reduce any potential
bias.
- It is not
considered that drilling orientation has introduced an appreciable
sampling bias.
|
Sample
security
|
- The measures taken
to ensure sample security.
|
- For samples assayed
at on-site laboratory facilities, samples are delivered to the
facility by Company staff. Upon delivery the responsibility for
sample security and storage falls to the independent third-party
operators of these facilities.
- For samples assayed
off-site, samples are delivered to a third-party transport service,
who in turn relay them to the independent laboratory contractor.
Samples are stored securely until they leave site.
|
Audits or
reviews
|
- The results of any
audits or reviews of sampling techniques and data
|
- Site generated
resources and reserves and the parent geological data is routinely
reviewed by the Westgold Corporate technical team.
|
SECTION 2: REPORTING OF EXPLORATION RESULTS
(Criteria listed in the preceding section also apply to this
section.)
Criteria
|
JORC Code
Explanation
|
Commentary
|
Mineral tenement and
land tenure status
|
- Type, reference
name/number, location and ownership including agreements or
material issues with third parties such as joint ventures,
partnerships, overriding royalties, native title interests,
historical sites, wilderness or national park and environmental
settings.
- The security of the
tenure held at the time of reporting along with any known
impediments to obtaining a licence to operate in the
area.
|
- Native title
interests are recorded against several WGX tenements.
- The CMGP tenements
are held by the Big Bell Gold Operations (BBGO) of which Westgold
has 100% ownership.
- Several third-party
royalties exist across various tenements at CMGP, over and above
the state government royalty.
- The Fortnum Gold
Project tenure is 100% owned by Westgold through subsidiary company
Aragon Resources Pty. Ltd. Various Royalties apply to the package.
The most pertinent being;
- State Government –
2.5% NSR
- Beta Hunt is owned
by Westgold through a sub-lease agreement with St Ives Gold Mining
Company Pty Ltd (SIGMC), which gives Westgold the right to explore
and mine gold and nickel.
- Royalties on gold
production from Beta Hunt are as follows:
-
- A royalty to the
state government equal to 2.5% of the royalty value of gold metal
produced; and
- Royalties to third
parties equal to 4.75% of recovered gold less allowable
deductions.
- The
Higginsville-Lakewood Operations include the Higginsville and
Lakewood Mills and associated infrastructure, mining operations and
exploration prospects which are located on 242 tenements owned by
Westgold and covers approximately 1,800km2 total area.
- Royalties on the
HGO gold production are as follows:
-
- Production payments
of up to 1% of gross gold revenue over various tenements to
traditional land owners.
- Royalty equal to
2.5% of recovered gold to the Government of Western Australia;
and
- Various third
parties hold rights to receive royalties in respect of gold (and in
some cases other minerals or metals) recovered from the
tenements.
- The tenure is
currently in good standing
- There are no known
issues regarding security of tenure.
- There are no known
impediments to continued operation.
- WGX operates in
accordance with all environmental conditions set down as conditions
for grant of the leases.
|
Exploration done by
other parties
|
- Acknowledgment and
appraisal of exploration by other parties
|
- The CMGP tenements
have an exploration and production history in excess of 100
years.
- The FGP tenements
have an exploration and production history in excess of 30
years.
- BH tenements have
an exploration and production history in excess of 60
years.
- HGO tenements have
an exploration and production history in excess of 40
years.
- Westgold work has
generally confirmed the veracity of historic exploration
data.
|
Geology
|
- Deposit type,
geological setting and style of mineralisation.
|
BHO
- Beta Hunt is
situated within the central portion of the Norseman-Wiluna
greenstone belt in a sequence of mafic/ultramafic and felsic rocks
on the southwest flank of the Kambalda Dome.
- Gold mineralsation
occurs mainly in subvertical shear zones in the Lunnon Basalt and
is characterised by shear and extensional quartz veining within a
halo of biotite/pyrite alteration. Within these shear zones, coarse
gold sometimes occurs where the shear zones intersect iron-rich
sulphidic metasediments in the Lunnon Basalt or nickel sulphides at
the base of the Kambalda Komatiite (ultramafics). The mineralized
shears are represented by A-Zone, Western Flanks, Larkin and Mason
zones.
|
CGO
- CGO is located in
the Achaean Murchison Province, a granite-greenstone terrane in the
northwest of the Yilgarn Craton. Greenstone belts trending
north-northeast are separated by granite-gneiss domes, with smaller
granite plutons also present within or on the margins of the
belts.
- Mineralisation at
Big Bell is hosted in the shear zone (Mine Sequence) and is
associated with the post-peak metamorphic retrograde assemblages.
Stibnite, native antimony and trace arsenopyrite are disseminated
through the K-feldspar-rich lode schist. These are intergrown with
pyrite and pyrrhotite and chalcopyrite. Mineralisation outside the
typical Big Bell host rocks (KPSH), for example 1,600N and Shocker,
also display a very strong W-As-Sb geochemical halo.
- Numerous gold
deposits occur within the Cuddingwarra Project area, the majority
of which are hosted within the central mafic-ultramafic ± felsic
porphyry sequence. Within this broad framework, mineralisation is
shown to be spatially controlled by competency contrasts across,
and flexures along, layer-parallel D2 shear zones, and is maximised
when transected by corridors of northeast striking D3 faults and
fractures.
- The Great Fingall
Dolerite hosts the majority gold mineralisation within the portion
of the greenstone belt proximal to Cue (The Day Dawn Project Area).
Unit AGF3 is the most brittle of all the five units and this
characteristic is responsible for its role as the most favourable
lithological host to gold mineralisation in the Greenstone
Belt.
|
FGO
- The Fortnum
deposits are Paleoproterozoic shear-hosted gold deposits within the
Fortnum Wedge, a localised thrust duplex of Narracoota Formation
within the overlying Ravelstone Formation. Both stratigraphic
formations comprise part of the Bryah Basin in the Capricorn
Orogen, Western Australia.
- The Horseshoe
Cassidy deposits are hosted within the Ravelstone Formation
(siltstone and argillite) and Narracoota Formation (highly altered,
moderate to strongly deformed mafic to ultramafic rocks). The main
zone of mineralisation is developed within a horizon of highly
altered magnesian basalt. Gold mineralisation is associated with
strong vein stock works that are confined to the altered mafic.
Alteration consists of two types: stockwork proximal
silica-carbonate-fuchsite-haematite-pyrite and distal
silica-haematite-carbonate+/- chlorite.
- The Peak Hill
district represents remnants of a Proterozoic fold belt comprising
highly deformed trough and shelf sediments and mafic / ultramafic
volcanics, which are generally moderately metamorphosed (except for
the Peak Hill Metamorphic Suite).
HGO
- The Higginsville
Gold Operation is located in the Eastern Goldfields Superterrane of
the Archean Yilgarn Craton. The bulk of the Higginsville tenement
package is located almost entirely within the well-mineralised
Kalgoorlie Terrane, between the gold mining centres of Norseman and
St Ives. HGO can be sub-divided into seven major geological
domains: Trident Line of Lode, Chalice, Lake Cowan, Southern
Paleo-channels, Mt Henry, Polar Bear Group and Spargos Project
area.
- Majority of
mineralisation along the Trident Line of Lode are hosted within the
Poseidon gabbro and high-MgO dyke complexes in the south. The
Poseidon Gabbro is a thick, weakly-differentiated gabbroic sill,
which strikes north-south and dips 60° to the east, is over 500 m
thick and 2.5 km long. The mineralisation is hosted within or
marginal to quartz veining and is structurally and lithologically
controlled.
- The Chalice Deposit
is located within a north-south trending, 2 km to 3 km wide
greenstone terrane, flanked on the west calc-alkaline granitic
rocks of the Boorabin Batholith and to the east by the Pioneer Dome
Batholith. The dominant unit that hosts gold mineralisation is a
fine grained, weak to strongly foliated amphibole-plagioclase
amphibolite, with a typically lepidoblastic (mineralogically
aligned and banded) texture. It is west-dipping and generally
steep, approximately 60° to 75°.
- The Lake Cowan
project area is situated near the centre of a regional anticline
between the Zuleika and Lefroy faults, with the local geology of
the area made more complex by the intrusion of the massive
Proterozoic Binneringie dyke. The majority of mineralisation at the
Lake Cowan Mining Centre is hosted within an enclave of Archaean
material surrounded by the Binneringie dyke.
- Mineralised zones
within the Southern Paleo Channels network comprise both placer
gold, normally near the base of the channel-fill sequences, and
chemically-precipitated secondary gold within the channel-fill
materials and underlying saprolite. These gold concentrations
commonly overlie, or are adjacent to, primary mineralised zones
within Archaean bedrock.
- The Mount Henry
Project covers 347km2 of the prolific South Norseman‐Wiluna
Greenstone belt of the Eastern Goldfields in Western Australia.
Although the greenstone rocks from the Norseman area can be broadly
correlated with those of the Kalgoorlie – Kambalda region they form
a distinct terrain which is bounded on all sides by major regional
shears. The Norseman Terrane has prominent banded iron formations
which distinguish it from the Kalgoorlie– Kambalda Terrane. The
Mount Henry gold deposit is hosted by a silicate facies BIF unit
within the Noganyer Formation. Gold mineralisation is predominantly
hosted by the silicate facies BIF unit but is also associated with
minor meta‐basalt and dolerite units that were mostly emplaced in
the BIF prior to mineralisation. The footwall to the BIF is
characterised by a sedimentary schistose unit and the hanging wall
by the overlying dolerites of the Woolyeener Formation. The Mount
Henry gold deposit is classified as an Archean, orogenic shear
hosted deposit. The main lode is an elongated, shear‐hosted body,
1.9km long by 6 – 10 metres wide and dips 65‐75 degrees towards the
west.
- The Polar Bear
project is situated within the Archaean Norseman-Wiluna Belt which
locally includes basalts, komatiites, metasediments, and felsic
volcaniclastics. The primary gold mineralisation is related to
hydrothermal activity during multiple deformation events.
Indications are that gold mineralisation is focused on or near to
the stratigraphic boundary between the Killaloe and Buldania
Formation.
- The Spargos Project
occurs within Coolgardie Domain of the Kalgoorlie Terrane. The area
is bounded by the Zuleika Shear to the east and the Kunanalling
Shear to the west. The geological setting comprises tightly-folded
north-south striking ultramafic and mafic volcanic rocks at the
northern closure Widgiemooltha Dome. The project lies on the
general trend of the Kunanalling / Karramindie Shear corridor, a
regional shear zone that hosts significant mineralisation to the
north at Ghost Crab (Mount Marion), Wattle Dam to the south, the
Penfolds group and Kunanalling. The regional prospective Zuleika
Shear lies to the east of the project. The tenements are
prospective for vein and shear hosted gold deposits as demonstrated
by Spargos Reward and numerous other gold workings and occurrences.
Gold mineralisation at Spargos Reward is hosted by a coarse-grained
pyrite-arsenopyrite lode in quartz-sericite schists, between
strongly biotitic altered greywacke to the east and
quartz-sericite-fuchsite-pyrite altered felsic tuff to the west.
Gold mineralisation is associated with very little quartz veining
which is atypical for many deposits in region. The Spargos Reward
setting has been described variously as a low-quartz sulphidic
mesothermal gold system or as a Hemlo style syn-sedimentary
occurrence.
MGO
- MGO is located in
the Achaean Murchison Province, a granite-greenstone terrane in the
northwest of the Yilgarn Craton. Greenstone belts trending
north-northeast are separated by granite-gneiss domes, with smaller
granite plutons also present within or on the margins of the
belts.
- The Paddy's Flat
area is located on the western limb of a regional fold, the Polelle
Syn- cline, within a sequence of mafic to ultramafic volcanics with
minor interflow sediments and banded iron-formation. The sequence
has also been intruded by felsic porphyry dykes prior to
mineralisation. Mineralisation is located along four sub-parallel
trends at Paddy's Flat which can be summarized as containing three
dominant mineralisation styles:
- Sulphide
replacement BIF hosted gold. Quartz vein hosted shear-related
gold.
- Quartz-carbonate-sulphide stockwork vein and
alteration related gold.
- The Yaloginda area
which host Bluebird – South Junction, is a gold-bearing Archaean
greenstone belt situated ~15km south of Meekatharra. The deposits
in the area are hosted in a strained and metamorphosed volcanic
sequence that consists primarily of ultramafic and high-magnesium
basalt with minor komatiite, peridotite, gabbro, tholeiitic basalt
and interflow sediments. The sequence was intruded by a variety of
felsic porphyry and intermediate sills and dykes.
- The Reedy's mining
district is located approximately 15 km to the south-east to
Meekatharra and to the south of Lake Annean. The Reedy gold
deposits occur with- in a north-south trending greenstone belt, two
to five kilometres wide, composed of volcano-sedimentary sequences
and separated multiphase syn- and post-tectonic granitoid
complexes. Structurally controlled the gold occur.
|
|
|
|
Drill hole
Information
|
- A summary of all
information material to the understanding of the exploration
results including a tabulation of the following information for all
Material drill holes:
- easting and
northing of the drill hole collar
- elevation
or RL (Reduced Level – elevation above sea level in metres) of
the drill hole collar
- dip and azimuth of
the hole
- down hole length
and interception depth
- hole
length.
- If the exclusion of
this information is justified on the basis that the information is
not Material and this exclusion does not detract from the
understanding of the report, the Competent Person should clearly
explain why this is the case.
|
- Tables containing
drillhole collar, downhole survey and intersection data are
included in the body of the announcement.
- No explorations
results are being reported for Beta Hunt and Higginsville
Operations.
|
Data aggregation
methods
|
- In reporting
Exploration Results, weighting averaging techniques, maximum and/or
minimum grade truncations (e.g., cutting of high grades) and
cut-off grades are usually Material and should be
stated.
- Where aggregate
intercepts incorporate short lengths of high-grade results and
longer lengths of low-grade results, the procedure used for such
aggregation should be stated and some typical examples of such
aggregations should be shown in detail.
- The assumptions
used for any reporting of metal equivalent values should be clearly
stated.
|
- All results
presented are length weighted.
- No high-grade cuts
are used.
- Reported results
contain no more than two contiguous metres of internal dilution
below 0.5g/t. For Beta Hunt, a cut off of 1 g/t Au with maximum
internal waste of 2m is used to define significant
intercepts.
- Results are
reported above a variety of gram / metre cut-offs dependent upon
the nature of the hole. These are cut-offs are clearly stated in
the relevant tables.
- Unless indicated to
the contrary, all results reported are downhole width.
- Given restricted
access in the underground environment the majority of drillhole
intersections are not normal to the orebody.
|
Relationship between
mineralisation widths and intercept lengths
|
- These relationships
are particularly important in the reporting of Exploration
Results.
- If the geometry of
the mineralisation with respect to the drill hole angle is known,
its nature should be reported.
- If it is not known
and only the down hole lengths are reported, there should be a
clear statement to this effect (e.g., 'down hole length, true width
not known').
|
- Unless indicated to
the contrary, all results reported are downhole width.
- Given restricted
access in the underground environment the majority of drillhole
intersections are not normal to the orebody.
|
Diagrams
|
- Appropriate maps
and sections (with scales) and tabulations of intercepts should be
included for any significant discovery being reported These should
include, but not be limited to a plan view of drill hole collar
locations and appropriate sectional views.
|
- Appropriate
diagrams are provided in the body of the release if
required.
|
Balanced
reporting
|
- Where comprehensive
reporting of all Exploration Results is not practicable,
representative reporting of both low and high grades and/or widths
should be practiced to avoid misleading reporting of Exploration
Results.
|
- Appropriate balance
in exploration results reporting is provided.
|
Other substantive
exploration data
|
- Other exploration
data, if meaningful and material, should be reported including (but
not limited to): geological observations; geophysical survey
results; geochemical survey results; bulk samples – size and method
of treatment; metallurgical test results; bulk density,
groundwater, geotechnical and rock characteristics; potential
deleterious or contaminating substances.
|
- There is no other
substantive exploration data associated with this
release.
|
Further
work
|
- The nature and
scale of planned further work (e.g. tests for lateral extensions or
depth extensions or large-scale step-out drilling).
- Diagrams clearly
highlighting the areas of possible extensions, including the main
geological interpretations and future drilling areas, provided this
information is not commercially sensitive.
|
- Ongoing surface and
underground exploration activities will be undertaken to support
continuing mining activities at Westgold Gold
Operations.
|
SECTION 3: ESTIMATION AND REPORTING OF MINERAL
RESOURCES
(Criteria listed in section 1, and where relevant in section 2,
also apply to this section.)
Criteria
|
JORC Code
Explanation
|
Commentary
|
Database
integrity
|
- 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.
- Data validation
procedures used.
|
- The database used
for the estimation was extracted from the Westgold's DataShed
database management system stored on a secure SQL
server.
- As new data is
acquired it passes through a validation approval system designed to
pick up any significant errors before the information is loaded
into the master database.
|
Site
visits
|
- Comment on any site
visits undertaken by the Competent Person and the outcome of those
visits.
- If no site visits
have been undertaken indicate why this is the case.
|
- Mr. Russell visits
Westgold Gold Operations regularly.
|
Geological
interpretation
|
- Confidence in (or
conversely, the uncertainty of) the geological interpretation of
the mineral deposit.
- Nature of the data
used and of any assumptions made.
- The effect, if any,
of alternative interpretations on Mineral Resource
estimation.
- The use of geology
in guiding and controlling Mineral Resource estimation.
- The factors
affecting continuity both of grade and geology.
|
- Mining in the
Murchison and Goldfields districts has occurred since 1800's
providing significant confidence in the currently geological
interpretation across all projects.
- Confidence in the
geological interpretation at BHO is high. The current geological
interpretation has been a precursor to successful mining over the
years and forms the basis for the long-term life of mine plan
(LOM). The data and assumptions used do suggest that any
significant alternative geological interpretation is
unlikely.
- Geology
(lithological units, alterations, structure, veining) have been
used to guide and control Mineral Resource estimation for Beta Hunt
and HGO
- No alternative
interpretations are currently considered viable.
- Geological
interpretation of the deposit was carried out using a systematic
approach to ensure that the resultant estimated Mineral Resource
figure was both sufficiently constrained, and representative of the
expected sub-surface conditions. In all aspects of resource
estimation the factual and interpreted geology was used to guide
the development of the interpretation.
- Geological matrixes
were established to assist with interpretation and construction of
the estimation domains.
- The structural
regime is the dominant control on geological and grade continuity
in the Murchison and Goldfields. Lithological factors such as
rheology contrast are secondary controls on grade
distribution.
- Low-grade
stockpiles are derived from previous mining of the mineralisation
styles outlined above.
|
Dimensions
|
- 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 ineral Resource.
|
BHO
- A-Zone extends over
2.2km strike length and is modelled to a vertical depth of 960m. It
has variable thickness from 2m to 20m thick.
- Western Flanks has
a strike extent of 1.8km and is modelled to a vertical extent of
450m, with average thickness of the shear around 10m.
- Larkin extends over
1.1km in strike length and is modelled to 400m vertical extent,
with variable thickness ranging from 2m to 15m thick.
- Mason has a strike
extent of 1.1km and is modelled to 455m vertical extent with
variable thickness between 7 to 15m.
CGO
- The Big Bell Trend
is mineralised a strike length of >3,900m, a lateral extent of
up +50m and a depth of over 1,500m.
- Great Fingall is
mineralised a strike length of >500m, a lateral extent of
>600m and a depth of over 800m.
- Black Swan South is
mineralised a strike length of >1,700m, a lateral extent of up
+75m and a depth of over 300m.
FGP
- The Yarlarweelor
mineral resource extends over 1,400m in strike length, 570m in
lateral extent and 190m in depth.
- The Tom's and Sam's
mineral resource extends over 650m in strike length, 400m in
lateral extent and 130m in depth.
- The Eldorado
mineral resource extends over 240m in strike length, 100m in
lateral extent and 100m in depth.
HGO
- Trident, Fairplay,
Vine and Two Boy's deposits form the Line of Lode system and
extends over 5km of strike.
- Chalice
mineralisation has been defined over a strike length of 700m, a
lateral extent of 200m and a depth of 650m.
- The Pioneer
resource area extends over a strike length of 860m from 6,474,900mN
to 6,475,760mN. The multiple NS striking parallel lodes occur
within a narrow EW extent of 190m from 374,970mE to 375,160mE.
Mineralisation has been modelled from surface at 291mRL to a
vertical depth 208m to the 83mRL.
- Southern
paleochannels gold mineralisation is interpreted to have a strike
length around 4km and is predominantly flat lying.
- The Wills deposit
extends over 900m in a ENE-WSW direction and is up to 200m wide.
Pluto is confirmed between sections 6,480,100mN and 6,481,800mN.
Nanook is confirmed between sections 6,469,300mN and
6,472,500mN.
- Lake Cowan:
Atreides mineralisation is contained within flat lying lodes
located within the weathered zone. The mineralision strike extents
vary between 100m to 300m long, with an average thickness of 2 to 3
m thick. Josephine has a strike length greater than 450m and
>10m across strike and modelled to >90m at depth. Louis has a
strike extent of 310m long and is interpreted to a depth of 170m
below surface. Napoleon: ~220m strike and up to ~90m (individual
mineralised lodes maximum of 12m) across strike to an interpreted
depth of ~80m m below surface. Rose's dimension is 150m x 120m (X,
Y), to an interpreted depth of +20-25m below surface.
- The Spargos
resource area extends over a strike length of 330m from 6,542,980mN
to 6,543,310mN. The parallel lodes occur within a narrow EW extent
of 95m from 354,120mE to 354,215mE. Mineralisation has been
modelled from surface at 425mRL to a vertical depth 525m to
-100mRL.
MGO
- The Paddy's Flat
Trend is mineralised a strike length of >3,900m, a lateral
extent of up +230m and a depth of over 500m.
- Bluebird – South
Junction is mineralised a strike length of >1,800m, a lateral
extent of up +50m and a depth of over 500m.
- Triton – South Emu
is mineralised a strike length of >1,100m, a lateral extent of
several metres and a depth of over 500m.
STOCKPILES
- Low-grade
stockpiles are of various dimensions. All modelling and estimation
work undertaken by Westgold is carried out in three dimensions via
Surpac Vision.
|
Estimation and
modelling techniques.
|
- The nature and
appropriateness of the estimation technique(s) applied and key
assumptions, including treatment of extreme grade values,
domaining, interpolation parameters, maximum distance of
extrapolation from data points.
- The availability of
check estimates, previous estimates and/or mine production records
and whether the Mineral Resource estimate takes appropriate account
of such data.
- The assumptions
made regarding recovery of by-products.
- Estimation of
deleterious elements or other non-grade variables of economic
significance (e.g. sulphur for acid mine drainage
characterisation).
- In the case of
block model interpolation, the block size in relation to the
average sample spacing and the search employed.
- Any assumptions
behind modelling of selective mining units.
- Any assumptions
about correlation between variables.
- The process of
validation, the checking process used, the comparison of model data
to drillhole data, and use of reconciliation data if
available.
|
- After validating
the drillhole data to be used in the estimation, interpretation of
the orebody is undertaken in sectional and / or plan view to create
the outline strings which form the basis of the three-dimensional
orebody wireframe. Wireframing is then carried out using a
combination of automated stitching algorithms and manual
triangulation to create an accurate three-dimensional
representation of the sub-surface mineralised body.
- Drillhole
intersections within the mineralised body are defined, these
intersections are then used to flag the appropriate sections of the
drillhole database tables for compositing purposes. Drillholes are
subsequently composited to allow for grade estimation. In all
aspects of resource estimation, the factual and interpreted geology
was used to guide the development of the
interpretation.
- Once the sample
data has been composited, a statistical analysis is undertaken to
assist with determining estimation search parameters, top-cuts etc.
Variographic analysis of individual domains is undertaken to assist
with determining appropriate search parameters. Which are then
incorporated with observed geological and geometrical features to
determine the most appropriate search parameters.
- An empty block
model is then created for the area of interest. This model contains
attributes set at background values for the various elements of
interest as well as density, and various estimation parameters that
are subsequently used to assist in resource categorisation. The
block sizes used in the model will vary depending on orebody
geometry, minimum mining units, estimation parameters and levels of
informing data available.
- Grade estimation is
then undertaken, with ordinary kriging estimation method is
considered as standard, although in some circumstances where sample
populations are small, or domains are unable to be accurately
defined, inverse distance weighting estimation techniques will be
used. For very minor lodes, the respective median or average grade
is assigned. Both by-product and deleterious elements are estimated
at the time of primary grade estimation if required. It is assumed
that by- products correlate well with gold. There are no
assumptions made about the recovery of by-products.
- The resource is
then depleted for mining voids and subsequently classified in line
with JORC guidelines utilising a combination of various estimation
derived parameters and geological / mining knowledge.
- This approach has
proven to be applicable to Westgold's gold assets.
- Estimation results
are routinely validated against primary input data, previous
estimates and mining output.
- Good reconciliation
between mine claimed figures and milled figures are routinely
achieved during production.
|
Moisture
|
- Whether the
tonnages are estimated on a dry basis or with natural moisture, and
the method of determination of the moisture content.
|
- Tonnage estimates
are dry tonnes.
|
Cut-off
parameters
|
- The basis of the
adopted cut-off grade(s) or quality parameters applied.
|
- The cut off grades
used for the reporting of the Mineral Resources have been selected
based on the style of mineralisation, depth from surface of the
mineralisation and the most probable extraction technique and
associated costs.
|
Mining factors or
assumptions
|
- 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.
|
- Variable by
deposit.
- No mining dilution
or ore loss has been modelled in the resource model or applied to
the reported Mineral Resource.
|
Metallurgical
factors or assumptions
|
- 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.
|
- Not considered for
Mineral Resource. Applied during the Reserve generation
process.
|
Environmental
factors or assumptions
|
- 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.
|
- Westgold operates
in accordance with all environmental conditions set down as
conditions for grant of the respective leases.
|
Bulk
density
|
- 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.
- 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.
- Discuss assumptions
for bulk density estimates used in the evaluation process of the
different materials.
|
- Bulk density of the
mineralisation is variable and is for the most part lithology and
oxidation rather than mineralisation dependent.
- A large suite of
bulk density determinations has been carried out across the project
areas. The bulk densities were separated into different weathering
domains and lithological domains
- A significant past
mining history has validated the assumptions made surrounding bulk
density.
|
Classification
|
- The basis for the
classification of the Mineral Resources into varying confidence
categories.
- Whether appropriate
account has been taken of all relevant factors (i.e. 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).
- Whether the result
appropriately reflects the Competent Person's view of the
deposit.
|
- Resources are
classified in line with JORC guidelines utilising a combination of
various estimation derived parameters, input data and geological /
mining knowledge.
- Drillhole spacing
to support classification varies based upon lode characteristics.
Measured ranges from 15-35m, Indicated from 10-180m and Inferred
from 10-200m.
- This approach
considers all relevant factors and reflects the Competent Person's
view of the deposit
|
Audits or
reviews
|
- The results of any
audits or reviews of Mineral Resource estimates.
|
- Resource estimates
are peer reviewed by the Corporate technical team.
- No external reviews
have been undertaken.
|
Discussion of
relative accuracy/ confidence
|
- 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.
- 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.
- These statements of
relative accuracy and confidence of the estimate should be compared
with production data, where available.
|
- All currently
reported resource estimates are considered robust, and
representative on both a global and local scale.
- A continuing
history of mining with good reconciliation of mine claimed to mill
recovered provides confidence in the accuracy of the
estimates.
|
SECTION 4: ESTIMATION AND REPORTING OF ORE RESERVES
(Criteria listed in section 1, and where relevant in sections 2
and 3, also apply to this section.)
Criteria
|
JORC Code
Explanation
|
Commentary
|
Mineral Resource
estimate for conversion to Ore Reserves
|
- Description of the
Mineral Resource estimate used as a basis for the conversion to an
Ore Reserve.
- Clear statement as
to whether the Mineral Resources are reported additional to, or
inclusive of, the Ore Reserves.
|
- At all Operations
the Ore Reserve is based on the corresponding reported Mineral
Resource estimate.
- Mineral Resources
reported are inclusive of those Mineral Resources modified to
produce the Ore Reserve estimate.
- At all projects,
all Mineral Resources that have been converted to Ore Reserve are
classified as either an Indicated or Measured material.
|
Site
visits
|
- Comment on any site
visits undertaken by the Competent Person and the outcome of those
visits.
- If no site visits
have been undertaken indicate why this is the case.
|
- Mr. Leigh Devlin
has over 10 years' experience in the mining industry. Mr. Devlin
visits the mine sites on a regular basis and is one of the primary
engineers involved in mine planning, site infrastructure and
project management.
|
Study
status
|
- The type and level
of study undertaken to enable Mineral Resources to be converted to
Ore Reserves.
- The Code requires
that a study to at least Pre-Feasibility Study level has been
undertaken to convert Mineral Resources to Ore Reserves. Such
studies will have been carried out and will have determined a mine
plan that is technically achievable and economically viable, and
that material Modifying Factors have been considered
|
- Processing at the
Murchison operations has occurred continuously since 2015, with
previous production occurring throughout 1800's, 1900's and 2000's.
Processing at the Goldfields operations has occurred intermittently
since the 1980's and continuously since 2008 at
Higginsville.
- Various
mineralisation styles and host domains have been mined since
discovery. Mining during this time has ranged from open pit
cutbacks, insitu surface excavations to extensional underground
developments.
- Budget level, 24
month projected, forecasts are completed on a biannual basis,
validating cost and physical inventory assumptions and modelling.
These updated parameters are subsequently used for the basis of the
Ore Reserve modification and financial factors. A budget, based on
this announcement has been completed, the results of which are
currently considered commercially sensitive due to the reliance of
South Junction to the yet-to-be released guidance
figures.
- Following
exploration and infill drilling activity, Resource models are
updated on both the estimation of grade and classification. These
updated Resource Models then form the foundation for Ore Reserve
calculation.
- The Bluebird-South
Junction mine is currently under operation with a feasibility study
completed in 2019.
|
Cut-off
parameters
|
- The basis of the
cut-off grade(s) or quality parameters applied.
|
- Underground Mines -
Cut off grades are used to determine the economic viability of the
convertible Resource. COG for underground mines incorporate OPEX
development and production costs, grade control, haulage, milling,
administration, along with state and private royalty conditions,
Where an individual mine has different mining methods and or
various orebody style, COG calculations are determined for each
division. These cuts are applied to production shapes (stopes) as
well as high grade development. Additionally, an incremental COG is
applied to low grade development, whereby access to a high grade
area is required.
- On the basis of
above process, the COG is split into Mine Operating COG
(incremental grade) 2.1gt and Fully Costed COG (inclusive of
capital) 2.3gt.
- Open Pit Mines -
The pit rim cut-off grade (COG) was determined as part of the Ore
Reserve estimation. The pit rim COG accounts for grade control,
haulage, milling, administration, along with state and private
royalty conditions. This cost profile is equated against the value
of the mining block in terms of recovered metal and the expected
selling price. The COG is then used to determine whether or not a
mining block should be delivered to the treatment plant for
processing, stockpiled as low- grade or taken to the waste
dump.
- On the basis of
above process, COGs for the open pit mines range from 0.8g/t
(whereby the Mill is local to Resources and Mill recoveries are
greater than 90%) to 1.4g/t (regional pits with low Mill
recoveries).
- Stockpile COG – A
marginal grade was determined for each stockpile inventory to
ensure it was economically viable. The COG accounts for haulage,
milling, administration, along with state and private royalty
conditions. Each pile honoured its Mill recovery
percentage.
|
Mining factors or
assumptions
|
- The method and
assumptions used as reported in the Pre-Feasibility or Feasibility
Study to convert the Mineral Resource to an Ore Reserve (i.e.
either by application of appropriate factors by optimisation or by
preliminary or detailed design).
- The choice, nature
and appropriateness of the selected mining method(s) and other
mining parameters including associated design issues such as
pre-strip, access, etc.
- The assumptions
made regarding geotechnical parameters (e.g. pit slopes, stope
sizes, etc.), grade control and pre-production
drilling.
- The major
assumptions made and Mineral Resource model used for pit and stope
optimisation (if appropriate).
- The mining dilution
factors used.
- The mining recovery
factors used.
- Any minimum mining
widths used.
- The manner in which
Inferred Mineral Resources are utilised in mining studies and the
sensitivity of the outcome to their inclusion.
- The infrastructure
requirements of the selected mining methods.
|
- All Ore Reserve
inventories are based upon detailed 3-dimensional designs to ensure
practical mining conditions are met. Additionally, all Ore Reserve
inventories are above the mine specific COG(s) as well as
containing only Measured and Indicated material. Depending upon the
mining method – modifying factors are used to address hydrological,
geotechnical, minimum width and blasting conditions.
- Open Pit
Methodology
- Following
consideration of the various modifying factors the following rules
were applied to the reserve estimation process for the conversion
of measured and indicated resource to reserve for suitable
evaluation.
- The mining shape in
the reserve estimation is generated by a wireframe (geology
interpretation of the ore zone) which overlays the block model.
Where the wire frame cuts the primary block, sub blocks fill out
the remaining space to the wire frame boundary (effectively the
mining shape). It is reasonable to assume that the mining method
can selectively mine to the wire frame boundary with the additional
dilution provision stated below.
- Ore Reserves
are based on Pit shape designs – with appropriate modifications to
the original Whittle Shell outlines to ensure compliance with
practical mining parameters.
- Geotechnical
parameters aligned to the Open Pit Ore Reserves are either based on
observed existing pit shape specifics or domain specific
expectations / assumptions. Various geotechnical reports and
retrospective reconciliations were considered in the design
parameters. A majority of the open pits have a final design wall
angle of 39-46 degrees, which is seen as conservative.
- Dilution of the ore
through the mining process has been accounted for within the Ore
Reserve quoted inventory. Various dilution ratios are used to
represent the style of mineralisation. Where continuous, consistent
ore boundaries and grade represent the mineralised system the
following factors are applied: oxide 15%, transitional 17% and
fresh 19%. In circumstances where the orebody is less homogenous
above the COG then the following dilution factors are applied in
order to model correctly the inherent variability of extracting
discrete sections of the pit floor: oxide 17%, transitional 19% and
fresh 21%. To ensure clarity, the following percentages are
additional ore mined in relation to excavating the wire frame
boundary as identified in point 1 above, albeit at a grade of 0.0
g/t. The amount of dilution is considered appropriate based on
orebody geometry, historical mining performance and the size of
mining equipment to be used to extract ore.
- Expected mining
recovery of the ore has been set at 93%.
- Minimum mining
widths have been accounted for in the designs, with the utilisation
of 40t or 90t trucking parameters depending upon the size of the
pit excavation.
- No specific ground
support requirements are needed outside of suitable pit slope
design criteria based on specific geotechnical domains.
- Mining sequence is
included in the mine scheduling process for determining the
economic evaluation and takes into account available operating time
and mining equipment size and performance.
- No Inferred
material is included within the open pit statement, though in
various pit shapes inferred material is present. In these
situations this inferred material is classified as
waste.
Underground
Methodology
- All Underground
Reserves are based on 3D design strings and polygon derived stope
shapes following the Measured and Indicated Resource (in areas
above the Mine Operating COG). A complete mine schedule is then
derived from this design to create a LOM plan. and financial
analysis.
- At Bluebird a
mixture of narrow-vein Longhole open stoping is used, whilst in
South Junction it is determine due to the size and geometry of the
orebody that a bulk method will be employed.
- Mining heights and
widths are based on first principles and standardised mining
methods employed widely throughout Western Australia.
- Geotechnical
evaluations have been used in determining the size and filling
methodologies across both Bluebird and South Junction. Subsequent
costs associated with these methods have been included within the
study and budgeting formats.
- In large
disseminated orebodies sub level caving, sub level open stoping or
single level bench stoping production methodologies are
used.
- In narrow vein
laminated quartz hosted domains a conservative narrow bench style
mining method is used.
- In narrow flat
dipping deposits, a Flat Long Hole process is adopted (with fillets
in the footwall for rill angle) and or jumbo stoping.
- Stope shape
parameters have been based on historical data (where possible) or
expected stable hydraulic radius dimensions.
- Stope inventories
have been determined by cutting the geological wireframe at above
the area specific COG and applying mining dilution and ore loss
factors. The ore loss ratio accounts for pillar locations between
the stopes (not operational ore loss) whilst dilution allows for
conversion of the geological wireframe into a minable shape
(Planned dilution) as well as hangingwall relaxation and blasting
overbreak (unplanned dilution).
- Depending upon the
style of mineralisation, sub level interval, blasthole diameters
used and if secondary support is installed, total dilution ranges
from 10 to 35%.
- Minimum mining
widths have been applied in the various mining methods. The only
production style relevant to this constraint is 'narrow stoping' –
where the minimum width is set at 1.5m in a 17.0m sub level
interval.
- Mining operational
recovery for the underground mines is set at 85-100% due to the use
of remote loading units as well as paste filling activities. Mining
recovery is not inclusive of pillar loss – insitu mineralised
material between adjacent stope panels.
- Stope shape
dimensions vary between the various methods. Default hydraulic
radii are applied to each method and are derived either from
historical production or geotechnical reports / recommendations.
Where no data or exposure is available conservative HR values are
used based on the contact domain type.
- Mining sequence is
included in the mine scheduling process for determining the
economic evaluation and takes into account available operating time
and mining equipment size and performance.
|
Metallurgical
factors or assumptions
|
- The metallurgical
process proposed and the appropriateness of that process to the
style of mineralisation.
- Whether the
metallurgical process is well-tested technology or novel in
nature.
- The nature, amount
and representativeness of metallurgical test work undertaken, the
nature of the metallurgical domaining applied and the corresponding
metallurgical recovery factors applied.
- Any assumptions or
allowances made for deleterious elements.
- The existence of
any bulk sample or pilot scale test work and the degree to which
such samples are considered representative of the orebody as a
whole.
- For minerals that
are defined by a specification, has the ore reserve estimation been
based on the appropriate mineralogy to meet the
specifications?
|
BHO
- A long history of
processing through several CIL processing existing facilities
demonstrates the appropriateness of the process to the styles of
mineralisation considered.
- No deleterious
elements are considered, the long history of processing has shown
this to be not a material concern.
CGO
- CGO has an existing
conventional CIL processing plant.
- The plant has a
nameplate capacity of 1.4Mtpa though this can be varied between
1.2- 1.6Mtpa pending rosters and material type.
- Gold extraction is
achieved using two staged crushing, ball milling with gravity
concentration and Carbon in Leach.
- Despite CGO having
a newly commissioned processing plant (2012/13 and subsequently
restarted in 2018) a high portion of the Reserve mill feed have
extensive data when processed at other plants in the past 2-3
decades. This long history of processing demonstrates the
appropriateness of the process to the styles of mineralisation
considered.
- No deleterious
elements are considered, as a long history of processing has shown
this to be not a material concern.
- For the Reserve,
Plant recoveries of 80-93% have been utilised.
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|
|
FGO
- FGO has an existing
conventional CIL processing plant – which has been operational in
various periods since the late 1980's. The plant has a nameplate
capacity of 1.0Mtpa though this can be varied between 0.8-1.2Mtpa
pending rosters and material type.
- An extensive
database of historical CIL recoveries as well as detailed
metallurgical test work is available for the various deposits, and
these have been incorporated into the COG analysis and financial
models.
- For the Reserve,
Plant recoveries of 93-95% have been utilised.
HGO
- Gold extraction is
achieved using staged crushing, ball milling with gravity
concentration and Carbon in Leach. The Higginsville plant has
operated since 2008.
- Treatment of ore is
via conventional gravity recovery / intensive cyanidation and CIL
is applied as industry standard technology.
- Additional
test-work is instigated where notable changes to geology and
mineralogy are identified. Small scale batch leach tests on primary
Louis ore have indicated lower recoveries (80%) associated with
finer gold and sulphide mineralisation.
- There have been no
major examples of deleterious elements affecting gold extraction
levels or bullion quality. Some minor variations in sulphide
mineralogy have had short-term impacts on reagent
consumptions.
- No bulk sample
testing is required whilst geology/mineralogy is consistent based
on treatment plant performance.
MGO
- MGO has an existing
conventional CIL processing plant – which has been operational in
various periods since the late 1980's.
- The plant has a
nameplate capacity of 1.6Mtpa though this can be varied between
1.2- 1.8Mtpa pending rosters and material type.
- Gold extraction is
achieved using single stage crushing, SAG & ball milling with
gravity concentration and Carbon in Leach.
- A long history of
processing through the existing facility demonstrates the
appropriateness of the process to the styles of mineralisation
considered.
- No deleterious
elements are considered, as a long history of processing has shown
this to be not a material concern.
- For the Reserve,
Plant recoveries of 85-92% have been utilised.
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Environmental
|
- The status of
studies of potential environmental impacts of the mining and
processing operation. Details of waste rock characterisation and
the consideration of potential sites, status of design options
considered and, where applicable, the status of approvals for
process residue storage and waste dumps should be
reported.
|
BHO
- BHO operates under
and in compliance with a number of operating environmental plans,
which cover its environmental impacts and outputs as well as
reporting guidelines / frequencies.
- Various Reserve
inventories do not have current DMP / DWER licenses – though there
are no abnormal conditions / factors associated with these assets
which the competent person sees as potentially threatening to the
particular project.
- The operation is
frequently inspected by the regulatory authorities of DMP and DWER
with continual feedback on environmental best practice and
reporting results.
- Flood Management,
Inclement Weather and Traffic Management Plans existing for the
operation to minimise the risks of environmental
impacts.
- Standard Operating
Procedures for the transfer of hazardous materials and restocking
of Dangerous Goods existing on site to mitigate the risk of these
materials entering the environment.
CGO
- CGO operates under
and in compliance with a number of operating environmental plans,
which cover its environmental impacts and outputs as well as
reporting guidelines / frequencies.
- Various Reserve
inventories do not have current DMP / DWER licenses – though there
are no abnormal conditions / factors associated with these assets
which the competent person sees as potentially threatening to the
particular project.
- The operation is
frequently inspected by the regulatory authorities of DMP and DWER
with continual feedback on environmental best practice and
reporting results.
- Flood Management,
Inclement Weather and Traffic Management Plans existing for the
operation to minimise the risks of environmental
impacts.
- Standard Operating
Procedures for the transfer of hazardous materials and restocking
of Dangerous Goods existing on site to mitigate the risk of these
materials entering the environment.
FGO
- FGO operates under
and in compliance with a number of operating environmental plans,
which cover its environmental impacts and outputs as well as
reporting guidelines / frequencies.
- Various Reserve
inventories do not have current DMP / DWER licenses – though there
are no abnormal conditions / factors associated with these assets
which the competent person sees as potentially threatening to the
particular project.
- The operation is
frequently inspected by the regulatory authorities of DMP and DWER
with continual feedback on environmental best practice and
reporting results.
- Flood Management,
Inclement Weather and Traffic Management Plans existing for the
operation to minimise the risks of environmental
impacts.
- Standard Operating
Procedures for the transfer of hazardous materials and restocking
of Dangerous Goods existing on site to mitigate the risk of these
materials entering the environment.
HGO
- CGO operates under
and in compliance with a number of operating environmental plans,
which cover its environmental impacts and outputs as well as
reporting guidelines / frequencies.
- Various Reserve
inventories do not have current DMP / DWER licenses – though there
are no abnormal conditions / factors associated with these assets
which the competent person sees as potentially threatening to the
particular project.
- The operation is
frequently inspected by the regulatory authorities of DMP and DWER
with continual feedback on environmental best practice and
reporting results.
- Flood Management,
Inclement Weather and Traffic Management Plans existing for the
operation to minimise the risks of environmental
impacts.
- Standard Operating
Procedures for the transfer of hazardous materials and restocking
of Dangerous Goods existing on site to mitigate the risk of these
materials entering the environment.
MGO
- MGO operates under
and in compliance with a number of operating environmental plans,
which cover its environmental impacts and outputs as well as
reporting guidelines / frequencies.
- Various Reserve
inventories do not have current DMP / DWER licenses – though there
are no abnormal conditions / factors associated with these assets
which the competent person sees as potentially threatening to the
particular project.
- The operation is
frequently inspected by the regulatory authorities of DMP and DWER
with continual feedback on environmental best practice and
reporting results.
- Flood Management,
Inclement Weather and Traffic Management Plans existing for the
operation to minimise the risks of environmental
impacts.
- Standard Operating
Procedures for the transfer of hazardous materials and restocking
of Dangerous Goods existing on site to mitigate the risk of these
materials entering the environment.
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Infrastructure
|
- The existence of
appropriate infrastructure: availability of land for plant
development, power, water, transportation (particularly for bulk
commodities), labour, accommodation; or the ease with which the
infrastructure can be provided or accessed.
|
BHO
- BHO is currently
active and have substantial infrastructure in place including a
large amount of underground infrastructure, major electrical,
ventilation and pumping networks.
- Airstrip facilities
are available at the local Kambalda airstrip.
CGO
- CGO has an
operating plant and tailings storage facility, along with extensive
mechanical and electrical maintenance facilities.
- The site also
includes existing administration buildings as well as a 250-man
accommodation camp facility.
- Power is provided
by onsite diesel generation, with potable water sourced from nearby
bore water (post treatment).
- Communications and
roadways are existing.
- Airstrip facilities
are available at the local Cue airstrip (20km).
FGO
- FGO has an
operating plant and tailings storage facility, along with extensive
mechanical and electrical maintenance facilities.
- The site also
includes existing administration buildings as well as a 200-man
accommodation camp facility.
- Power is provided
by onsite diesel generation, with potable water sourced from nearby
bore water (post treatment).
- Communications and
roadways are existing.
- Airstrip facilities
are available on site.
HGO
- HGO is currently
active and have substantial infrastructure in place including a
large amount of underground infrastructure, major electrical,
ventilation and pumping networks. The main Higginsville location
has an operating CIL plant a fully equipped laboratory, extensive
workshop, administration facilities and a 350 person single person
quarters nearby.
- Infrastructure
required for open production is also in place.
- Airstrip facilities
are available at the local Kambalda airstrip.
MGO
- MGO has an
operating plant and tailings storage facility, along with extensive
mechanical and electrical maintenance facilities.
- The site also
includes existing administration buildings as well as a 300-man
accommodation camp facility.
- Power is provided
by onsite diesel generation, with potable water sourced from nearby
bore water (post treatment).
- Communications and
roadways are existing.
- Airstrip facilities
are available at the local Meekatharra airstrip (30km).
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Costs
|
- The derivation of,
or assumptions made, regarding projected capital costs in the
study.
- The methodology
used to estimate operating costs.
- Allowances made for
the content of deleterious elements.
- The source of
exchange rates used in the study.
- Derivation of
transportation charges.
- The basis for
forecasting or source of treatment and refining charges, penalties
for failure to meet specification, etc.
- The allowances made
for royalties payable, both Government and private.
|
BHO
- Processing costs
are based on actual cost profiles with variations existing between
the various oxide states.
- Site G&A and
portioned corporate overheads are included within the analysis
(based upon previous Budget years actuals).
- Mining costs are
derived primarily from the current contractor and owner-operator
cost profiles in the underground environment.
- For the underground
environment, if not site-specific mining rates are available, an
appropriately selected operating mine is used for the basis of cost
profiling.
- Geology and Grade
Control costs are incorporated in the overall cost profile and are
based upon previously reconciled Budgetary forecasts.
- Haulage costs used
are either contractual rates or if in the case where a mine has
none, a generic cost per tkm unit rate is utilised.
- Both state
government and private royalties are incorporated into costings as
appropriate.
CGO
- Processing costs
are based on actual cost profiles with variations existing between
the various oxide states.
- Site G&A and
portioned corporate overheads are included within the analysis
(based upon previous Budget years actuals).
- Mining costs are
derived primarily from the current contractor and owner-operator
cost profiles in the underground environment.
- For Open Pits where
no current mining cost profiles are available for a forecasted
Reserve, a historically 'validated' pit cost matrix is used – with
variation allowances for density, fuel price and gear
size.
- For the underground
environment, if not site-specific mining rates are available, an
appropriately selected operating mine is used for the basis of cost
profiling.
- Geology and Grade
Control costs are incorporated in the overall cost profile and are
based upon previously reconciled Budgetary forecasts.
- Haulage costs used
are either contractual rates or if in the case where a mine has
none, a generic cost per tkm unit rate is utilised.
- Both state
government and private royalties are incorporated into costings as
appropriate.
FGO
- Processing costs
are based on actual cost profiles with variations existing between
the various oxide states.
- Site G&A and
portioned corporate overheads are included within the analysis
(based upon previous Budget years actuals).
- Mining costs are
derived primarily from the current contractor and owner-operator
cost profiles in the underground environment.
- For Open Pits where
no current mining cost profiles are available for a forecasted
Reserve, a historically 'validated' pit cost matrix is used – with
variation allowances for density, fuel price and gear
size.
- For the underground
environment, if not site-specific mining rates are available, an
appropriately selected operating mine is used for the basis of cost
profiling.
- Geology and Grade
Control costs are incorporated in the overall cost profile and are
based upon previously reconciled Budgetary forecasts.
- Haulage costs used
are either contractual rates or if in the case where a mine has
none, a generic cost per tkm unit rate is utilised.
- Both state
government and private royalties are incorporated into costings as
appropriate.
HGO
- Processing costs
are based on actual cost profiles with variations existing between
the various oxide states.
- Site G&A and
portioned corporate overheads are included within the analysis
(based upon previous Budget years actuals).
- Mining costs are
derived primarily from the current contractor and owner-operator
cost profiles in the underground environment.
- For Open Pits where
no current mining cost profiles are available for a forecasted
Reserve, a historically 'validated' pit cost matrix is used – with
variation allowances for density, fuel price and gear
size.
- For the underground
environment, if not site-specific mining rates are available, an
appropriately selected operating mine is used for the basis of cost
profiling.
- Geology and Grade
Control costs are incorporated in the overall cost profile and are
based upon previously reconciled Budgetary forecasts.
- Haulage costs used
are either contractual rates or if in the case where a mine has
none, a generic cost per tkm unit rate is utilised.
- Both state
government and private royalties are incorporated into costings as
appropriate.
MGO
- Processing costs
are based on actual cost profiles with variations existing between
the various oxide states.
- Site G&A and
portioned corporate overheads are included within the analysis
(based upon previous Budget years actuals).
- Mining costs are
derived primarily from the current contractor and owner-operator
cost profiles in the underground environment.
- For Open Pits where
no current mining cost profiles are available for a forecasted
Reserve, a historically 'validated' pit cost matrix is used – with
variation allowances for density, fuel price and gear
size.
- For the underground
environment, if not site-specific mining rates are available, an
appropriately selected operating mine is used for the basis of cost
profiling.
- Geology and Grade
Control costs are incorporated in the overall cost profile and are
based upon previously reconciled Budgetary forecasts.
- Haulage costs used
are either contractual rates or if in the case where a mine has
none, a generic cost per tkm unit rate is utilised.
- Both state
government and private royalties are incorporated into costings as
appropriate.
|
Revenue
factors
|
- The derivation of,
or assumptions made regarding revenue factors including head grade,
metal or commodity price(s) exchange rates, transportation and
treatment charges, penalties, net smelter returns, etc.
- The derivation of
assumptions made of metal or commodity price(s), for the principal
metals, minerals and co-products.
|
- Mine Revenue, COGs,
open pit optimisation and royalty costs are based on the long-term
forecast of A$3,000/oz.
- No allowance is
made for silver by-products.
|
Market
assessment
|
- The demand, supply
and stock situation for the particular commodity, consumption
trends and factors likely to affect supply and demand into the
future.
- A customer and
competitor analysis along with the identification of likely market
windows for the product.
- Price and volume
forecasts and the basis for these forecasts.
- For industrial
minerals the customer specification, testing and acceptance
requirements prior to a supply contract.
|
- Detailed economic
studies of the gold market and future price estimates are
considered by Westgold and applied in the estimation of revenue,
cut-off grade analysis and future mine planning
decisions.
- There remains
strong demand and no apparent risk to the long-term demand for the
gold.
|
Economic
|
- The inputs to the
economic analysis to produce the net present value (NPV) in the
study, the source and confidence of these economic inputs including
estimated inflation, discount rate, etc.
- NPV ranges and
sensitivity to variations in the significant assumptions and
inputs.
|
- Each separate mine
(open pit, underground or stockpile) has been assessed on a
standard operating cash generating model. Capital costs have been
included thereafter to determine an economic outcome.
- Subsequently each
Operating centre (MGO, CGO and FGP) has had a Discounted Cash Flow
model constructed to further demonstrate the Reserve has a positive
economic outcome.
- A discount rate of
8% is allied in DCF modelling.
- No escalation of
costs and gold price is included.
- Sensitivity
analysis of key financial and physical parameters is applied to
future development projects.
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Social
|
- The status of
agreements with key stakeholders and matters leading to social
licence to operate.
|
BHO
- BHO is fully
permitted and a major contributor to the local and regional
economy. It has no external pressures that impact its operation or
which could potentially jeopardise its continuous
operation.
CGO
- CGO is fully
permitted and a major contributor to the local and regional
economy. It has no external pressures that impact its operation or
which could potentially jeopardise its continuous
operation.
- As new open pits or
underground operations develop the site will require separate
environmental approvals from the different regulating
bodies.
- Where required, the
operation has a Native Title and Pastoral Agreement.
FGO
- FGP is fully
permitted and a major contributor to the local and regional
economy. It has no external pressures that impact its operation or
which could potentially jeopardise its continuous
operation.
- As new open pits or
underground operations develop the site will require separate
environmental approvals from the different regulating
bodies.
- Where
required, the operation has a Native Title and Pastoral
Agreement.
HGO
- HGO is fully
permitted and a major contributor to the local and regional
economy. It has no external pressures that impact its operation or
which could potentially jeopardise its continuous
operation.
- As new open pits or
underground operations develop the site will require separate
environmental approvals from the different regulating
bodies.
MGO
- MGO is fully
permitted and a major contributor to the local and regional
economy. It has no external pressures that impact its operation or
which could potentially jeopardise its continuous
operation.
- As new open pits or
underground operations develop the site will require separate
environmental approvals from the different regulating
bodies.
- Where required, the
operation has a Native Title and Pastoral Agreement.
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Other
|
- To the extent
relevant, the impact of the following on the project and/or on the
estimation and classification of the Ore Reserves:
- Any identified
material naturally occurring risks.
- The status of
material legal agreements and marketing arrangements.
- The status of
governmental agreements and approvals critical to the viability of
the project, such as mineral tenement status, and government and
statutory approvals. There must be reasonable grounds to expect
that all necessary Government approvals will be received within the
timeframes anticipated in the Pre-Feasibility or Feasibility study.
Highlight and discuss the materiality of any unresolved matter that
is dependent on a third party on which extraction of the reserve is
contingent.
|
- BHO is an active
mining project.
- CGO is an active
mining project.
- FGO is an active
mining project.
- HGO is an active
mining project.
- MGO is an active
mining project.
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Classification
|
- The basis for the
classification of the Ore Reserves into varying confidence
categories.
- Whether the result
appropriately reflects the Competent Person's view of the
deposit.
- The proportion of
Probable Ore Reserves that have been derived from Measured Mineral
Resources (if any).
|
- The basis for
classification of the Resource into different categories is made in
accordance with the recommendations of the JORC Code 2012. Measured
Resources have a high level of confidence and are generally defined
in three dimensions with accurately defined or normally mineralised
developed exposure. Indicated resources have a slightly lower level
of confidence but contain substantial drilling and are in most
instances capitally developed or well defined from a mining
perspective. Inferred resources always contain significant
geological evidence of existence and are drilled, but not to the
same density. There is no classification of any resource that isn't
drilled or defined by substantial physical sampling
works.
- Some Measured
Resources have been classified as Proven and some are defined as
Probable Reserves based on internal judgement of the mining,
geotechnical, processing and or cost profile estimates.
- No Indicated
Resource material has been converted into Proven
Reserve.
- The resultant
Reserve classification appropriately reflects the view of the
Competent Person.
|
Audits or
reviews
|
- The results of any
audits or reviews of Ore Reserve estimates.
|
- Reserves
inventories and the use of appropriate modifying factors are
reviewed internally on an annual basis.
- Additionally, mine
design and cost profiles are regularly reviewed by WGX operational
quarterly reviews.
- Financial auditing
processes, Dataroom reviews for asset sales / purchases and
stockbroker analysis regularly 'truth test' the assumptions made on
Reserve designs and assumptions.
|
Discussion of
relative accuracy/ confidence
|
- Where appropriate a
statement of the relative accuracy and confidence level in the Ore
Reserve 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 reserve within stated confidence limits, or, if
such an approach is not deemed appropriate, a qualitative
discussion of the factors which could affect the relative accuracy
and confidence of the estimate.
- 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.
- Accuracy and
confidence discussions should extend to specific discussions of any
applied Modifying Factors that may have a material impact on Ore
Reserve viability, or for which there are remaining areas of
uncertainty at the current study stage.
- It is recognised
that this may not be possible or appropriate in all circumstances.
These statements of relative accuracy and confidence of the
estimate should be compared with production data, where
available.
|
- Whilst it should be
acknowledged that all Ore Reserves are based primarily upon an
estimate of contained insitu gold (Resource), it is the competent
person's view that the consolidated Reserve inventory is highly
achievable in entirety.
- Given the entire
Ore Reserves inventory is within existing operations, with
Budgetary style cost models and current contractual mining /
processing consumable rates, coupled with an extensive historical
knowledge / dataset of the Resources, it is the competent person's
view that the significant mining modifying factors (COGs,
geotechnical parameters and dilution ratio's) applied are
achievable and or within the limits of 10% sensitivity
analysis.
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SOURCE Westgold Resources Limited