REG - Artemis Resources Ld - High-Grade Resource at Greater Carlow
13/10/2022 07:01
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RNS Number : 7046C Artemis Resources Limited 13 October 2022
13 October 2022
Artemis Resources Limited
("Artemis" or the "Company")
(ASX/AIM: ARV, FRA: ATY, US: ARTTF)
High-Grade Resource at Greater Carlow
Artemis Resources Limited is pleased to provide an update on a new Inferred
JORC Mineral Resource at its 100%-owned Greater Carlow Project, located in the
Pilbara Region of Western Australia.
Highlights
704,000 oz Au Eq. at 2.5 g/t Au Eq 1 from 8.74 Mt, combined open pit and
underground.
A high-grade gold copper cobalt project primed for further growth:
· Conservative assumptions underlying the new resource estimate reflect
the robust nature of the project and take into consideration the recent rising
cost environment.
· The Greater Carlow resource compares very favourably to other gold
mining projects on a grade equivalent basis.
· Inferred Mineral Resource completed for the Greater Carlow gold
copper cobalt project reported in accordance with The JORC Code 2012.
· Total Inferred Mineral Resource of 8.74 Mt at 2.5 g/t Au Eq
comprises:
o Open pit resource of 7.25 Mt at 2.4 g/t Au Eq. for 557 Koz Au Eq.
§ (using a 0.7 g/t Au Eq. cut-off grade).
o Underground resource of 1.49 Mt at 3.1 g/t Au Eq. for 146 Koz Au Eq.
§ (using a 2 g/t Au Eq. cut-off grade).
· With this high-grade resource open in multiple directions exploration
will now push on to seek to grow resources further.
Alastair Clayton, Executive Director, commented: "On behalf of Artemis I am
delighted to report to shareholders the results of our updated resource model.
What we have now established at the Greater Carlow Project is a robust,
credible, high-grade multi-metal resource from which our exploration team can
now seek to continue to grow via drilling. The next phase at Greater Carlow is
to drill and add more high-grade tonnes to the open pit and underground
resources, including the high-grade Keel Zone which is not included in this
resource statement.
Importantly, this resource has taken into consideration recent industry cost
escalation and still returned robust results. There is an adage used in mining
that "grade is king", we believe this is as relevant today as it ever was.
With a diverse potential product stream of gold and the key battery metals of
copper and cobalt we believe Greater Carlow grade ranks very favourably
against other comparable Western Australian pre-development resource projects.
Furthermore, Greater Carlow's enviable project location likely obviates the
need for a future development to finance and operate a range of expensive
capital items such as airstrip, accommodation village, power station, water
plant etc. as well as contribute strongly to local communities by utilizing a
non-FIFO workforce.
With one of the world's largest green energy projects, the Asian Renewable
Energy Hub supporting 26 GW of combined solar and wind power generating
capacity being proposed by BP in the Pilbara, the Greater Carlow project also
has potential to further garner its ESG credentials as a sustainable battery
metals and gold producer.
We look forward to updating shareholders with our next steps for the project
and I would like to thank our geological team and consultants for the resource
update delivered today."
The resource has significant scope to grow in the near term
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Figure 1. Oblique view of the model showing potential continuations of known
mineralised zones.
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Figure 2. Long Section (looking north) model showing key domains and potential
continuations of known mineralised zones.
Resource modelling has identified immediate opportunities to grow the open pit
and underground resource with further drilling
· Scope to grow the open pit resource, Figures 1 and 2.
o Crosscut zone remains open to the north.
o High-grade shoots have been identified in the block model that will
benefit from additional drilling.
o Additional RC and diamond core drilling to increase the open pit resource
is currently being planned.
o Additional core drilling for samples for metallurgical test work.
· Scope to grow the underground resource, Figures 1 and 2.
o Gold and copper mineralisation open at depth as demonstrated by previous
drilling at Carlow Deeps (or Carlow Keel) (refer to Artemis press release
dated 23 November 2020).
o Additional RC and diamond core drilling to test depth extensions at
Crosscut and Carlow Main eastern zones are currently being planned.
o Additional core drilling for samples for metallurgical test work.
Tier 1 location
· Western Australia was ranked the No. 1 mining investment jurisdiction
in the 2021 Fraser Institute Annual Survey of Mining Companies.
· The Greater Carlow project is superbly located 25 km due east of the
city of Karratha and 9 km to the west of the town of Roebourne.
· Access is via the North West Coastal National Highway and established
haul road.
· Any future mine development would benefit from proximity to a
resident skilled labour pool, established mining contractors, as well as
adjacent high voltage power lines, gas, water, a nearby rail line, port and 17
daily jet flights from Karratha to Perth.
Independent Mineral Resource estimate
· Resource estimation undertaken by mining consultants Snowden Optiro
in collaboration with Artemis.
· Exhaustive estimation process, including:
o Data verification - site visit for geological familiarisation, review of
on-site processes, high level review of drillhole database, and review of
sampling, assaying and QAQC.
o Resource estimation and reporting - new mineralisation wireframes, data
analysis, kriging neighbourhood optimisation, cut-off grade determinations,
and block model reported considering reasonable prospects for eventual
economic extraction (RPEEE) using Whittle for open pit and Datamine Mineable
Shape Optimiser (MSO) for underground reportable resources.
o Classification - reported in accordance with the Australasian Code for
Reporting of Exploration results, Mineral Resources and Ore Reserves (The JORC
Code, 2012).
o Internal peer review by Snowden Optiro.
Greater Carlow - Mineral Resource statement
The Mineral Resource for Greater Carlow as at 13 October 2022 is presented in
Tables 1 to 4 and Figures 1-4. All three deposits forming Greater Carlow are
open at depth, and Quod Est and Crosscut are open along strike (Figure 1 and
2).
Table 1. Greater Carlow Inferred Mineral Resources by assumed mining method
reported above a cut-off of 0.7 g/t Au Eq. within an optimised open pit shell
and above a 2 g/t Au Eq. cut-off for underground using MSO shapes (current as
at 13 October 2022). The entire resource is classified as an Inferred Mineral
Resource in accordance with The JORC Code, 2012. All tonnes are dry metric
tonnes. Figures may not compute due to rounding.
OP or UG Au Eq. cut-off (g/t) Tonnes Au Eq. (g/t) Au (g/t) Cu (%) Co (%) Au (oz) Cu (t) Co (t)
(Mt)
Open pit 0.7 7.25 2.4 1.3 0.73 0.09 296,000 53,000 6,500
Underground 2.0 1.49 3.1 1.6 0.72 0.12 78,000 11,000 1,800
Total - 8.74 2.5 1.3 0.73 0.09 374,000 64,000 8,000
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Figure 3. Oblique view showing potential open pit (grey) and underground
(blue) mining method for Inferred Mineral resource.
Table 2. Greater Carlow Mineral Resources by weathering state reported above a
cut-off of 0.7 g/t Au Eq. within an optimised open pit shell and above a 2 g/t
Au Eq. cut-off for underground using MSO shapes (current as at 13 October
2022). The entire resource is classified as an Inferred Mineral Resource in
accordance with The JORC Code, 2012. All tonnes are dry metric tonnes. Figures
may not compute due to rounding.
Domain Tonnes Au Eq. (g/t) Au (g/t) Cu (%) Co (%) Au (oz) Cu (t) Co (t)
(Mt)
Oxide 1.29 1.5 0.8 0.59 0.07 34,000 8,000 1,000
Transition 1.49 2.0 1.2 0.84 0.09 56,000 13,000 1,000
Fresh 5.96 2.8 1.5 0.73 0.10 285,000 44,000 6,000
Total 8.74 2.5 1.3 0.73 0.09 374,000 64,000 8,000
Table 3. Greater Carlow Mineral Resources reported by area above a cut-off of
0.7 g/t Au Eq. within an optimised pit shell (current as at 13 October 2022).
The entire resource is classified as an Inferred Mineral Resource in
accordance with The JORC Code, 2012. All tonnes are dry metric tonnes. Figures
may not compute due to rounding.
Area Tonnes Au Eq. (g/t) Au (g/t) Cu (%) Co (%) Au (oz) Cu (t) Co (t)
(Mt)
Main 6.33 2.4 1.3 0.70 0.08 271,000 44,300 5,100
Quod Est 0.19 3.2 1.5 0.85 0.24 9,000 1,600 450
Crosscut 0.73 2.2 0.7 0.99 0.09 16,000 7,300 650
Total 7.25 2.4 1.3 0.73 0.09 296,000 53,200 6,200
Table 4. Greater Carlow Mineral Resources reported by area above a cut-off of
2 g/t Au Eq. for underground using MSO shapes (current as at 13 October 2022).
The entire resource is classified as an Inferred Mineral Resource in
accordance with The JORC Code, 2012. All tonnes are dry metric tonnes. Figures
may not compute due to rounding.
Area Tonnes Au Eq. (g/t) Au (g/t) Cu (%) Co (%) Au (oz) Cu (t) Co (t)
(Mt)
Main 1.09 3.1 1.9 0.57 0.11 66,000 6,250 1,200
Crosscut 0.39 3.1 1.0 1.14 0.14 12,500 4,450 550
Total 1.49 3.1 1.6 0.72 0.12 78,500 10,700 1,750
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Figure 4. Block model long section (looking north) coloured on resource
classification where Green = Inferred and Blue = Unclassified.
The following sections have been provided in fulfilment of ASX Listing Rule
5.8.1.
Geology and mineralisation
The Greater Carlow project is hosted by mafic Archaean volcanic arc rocks. The
Carlow Main and Quod Est deposits are hosted within structurally controlled,
mineralised zones occurring at right-angles to each other. The recently
defined Crosscut deposit is located approximately 200 m north of Carlow Main
and strikes north-south, sub-parallel to Quod Est (Figure 5). Mineralisation
is hosted within chloritic shear zones in basalts and is focussed along
contacts between the host basalt and footwall and hangingwall gabbro units. At
Carlow Main, mineralisation dips steeply north at the western end, while at
the eastern end the mineralisation dips steeply south. The Carlow Main deposit
strikes over 1.2 km and is partially oxidised from depths of 40 m to as much
as 100 m in the east. Mineralisation trends are complex, with gold, copper and
cobalt occurring across multiple lithologies. Some structural control on
mineralisation is likely, with high-grade trends identified within Carlow Main
(Figure 2). The Quod Est and Crosscut mineralisation is hosted by north-south
chloritic shear zones, and is partially oxidised above 25 m.
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Figure 5. Oblique overview of Greater Carlow area showing Carlow Main, Quod
Est and Crosscut.
Drilling, sampling, analysis and QAQC
Both Reverse Circulation (RC) and diamond core has been used to drill out the
geological sequences and identify zones of mineralisation. RC samples
comprised 58,261 m or 89% and HQ3 quarter (1,116: 33%) and half (3,685: 77%)
core samples comprised 7,094 m or 11% of the total drilling at Greater Carlow.
RC drilling was used to obtain one metre samples, using a 4.5" (112.5 mm) or
5.25" (131.2 mm) face sampling hammer. The entire RC sample was extracted
prior to subsampling at surface next to the rig. Field duplicates were taken
on selected intervals within the interpreted mineralised horizons. Duplicates
were collected at the rig from a static cone splitter, with the primary and
duplicate sample simultaneously collected from separate outlets. The cyclone
was cleaned between rod changes to minimise contamination. Samples were
collected via a rig-mounted splitter to yield sub-samples of approximately 3
kg per 1 m sample length. If any mineralised samples were collected wet, they
were noted in the drill logs and database. The rig splitter provided a primary
sample of 20-30 kg, and a sub-sample of 2-4 kg for every metre drilled. RC
sample recoveries were recorded by the field geologist in the field during
logging and sampling. If poor sample recovery was encountered during drilling,
the supervising geologist and driller endeavoured to rectify the problem to
ensure maximum and representative sample recovery. Visual assessments for
moisture and possible contamination were made by a field geologist. Minor damp
samples were encountered, with the field geologist and driller ensuring the
cleanliness of the cyclone and splitter. A cyclone and static cone splitter
were used to ensure representative RC sampling and were routinely inspected
and cleaned during drilling. Sample recoveries during drilling completed by
Artemis were high, with average overall recovery at 97%. Almost all samples
were dry.
Diamond sampling techniques employed at the Artemis core facility include saw
cut HQ3 (63 mm) half drill core samples. Sample intervals for diamond ranged
from 0.3 m to 1.5 m of which 97% are 1 m length. Triple-tube HQ3 core
drilling was completed to maximise diamond core recoveries. For drilling in
2017 and 2018 diamond core was cut into two quarters and one half using a core
saw. One of the quarter core segments was placed into a numbered calico bag,
which was then tied and placed in a plastic/polyweave bag. For drilling in
2020 and 2021, diamond core was cut into two halves using a diamond core saw.
One of the halves was placed into a numbered calico bag, which was tied and
placed in a plastic/polyweave bag. Drill core sample recoveries were recorded
by the field geologist in the field during logging and sampling. Core
recoveries were calculated based on nominal run lengths versus measured
lengths of recovered core. Sample recoveries during drilling completed by
Artemis were high, with average overall recovery for diamond core 1 m samples
at 97%.
For all samples, laboratory preparation consisted of drying, coarse crushing
to c. 10 mm, riffle splitting 2-4 kg followed by pulverisation in an LM5 or
equivalent pulverising mill to a grind size of 85% passing 75 microns. All
assays were by 30-50 g fire assay.
QC procedures involve the insertion of Internal Reference Materials (IRM),
along with duplicates and blank samples. IRMs are based on material with a
local matrix matched composition which underwent a round-robin process
involving five laboratories analysing ten 100 g pouches for Au, Cu and Co. The
insertion rate of each these was approximately 1 in 20. For RC and diamond
drilling, field duplicates were collected at the rig at a rate of
approximately 1 in 20.
Geological and mineralisation modelling and grade estimation methodology
Geological modelling of mineralised domains was undertaken in Leapfrog Geo
using the vein modelling tools (Figure 6). Separate mineralised vein domains
were built from a merged table using assay data. An interval selection table
was derived from the merged table to selectively code the drillholes to
facilitate the construction of vein systems. The mineralised vein system used
a nominal lower grade cut-off of both 0.3% Cu and 0.5 g/t Au as determined
from exploratory data analysis. Three separate mineralised vein systems were
created for Main Trend, Crosscut and Quod Est. Main Trend comprises 22 domains
(1010-1220), Crosscut comprises six domains (2010-2060) and Quod Est comprises
three domains (3010-3030). The wireframes can be considered as hard-wireframed
solids and are not derived from a grade shell interpolant process. A
mineralised envelope was created using the distance to object function, set at
+25 m from the final vein merged systems; this represented the approximate
volume of a 0.2% copper halo identified within the Greater Carlow mineralised
system. A separate mineralised halo was created for Main Trend (9990) and a
combined halo created for Crosscut and Quod Est (9980). Veins were visually
checked for thickness, continuity, and extents. Areas of extrapolation used
half the drill spacing as a limiting distance. Vein relationships were
assessed individually and a priority, i.e. termination on adjacent domains,
was set. Vein pinch-outs and pinch-outs around drillholes were used where data
supported this requirement.
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Figure 6. Plan displaying the new wireframes.
Wireframes were exported from Leapfrog Geo to Datamine Studio RM Pro software
for the purposes of data coding and estimation. Exploratory data analysis was
undertaken on coded samples, using Snowden Supervisor software, to understand
data distribution, boundary analysis for weathering relationships, elemental
correlation within modelled domains and sample lengths. Samples were
composited within domained surfaces (weathering and domain boundaries) to 1 m
representing the typical sample length of the data at Greater Carlow. 97% of
the sample data occurs within the 0.93-1.02 m range.
Weathering domains were coded to the mineralised domain intercepts covering
overburden, oxide, transitional and fresh profiles. For the purposes of
estimation the overburden and oxide domains were combined, and the
transitional and fresh domains were also combined based on contact boundary
analysis. This is expected to honour the mineral speciation between the two
principal weathering domains.
Dynamic Anisotropy, a process of locally rotating search orientations with the
strike/dip and plunge of the domain, was applied and directions were estimated
into the block model prior to grade estimation. The dip and dip direction were
derived from a central domain reference surface built from sample point
centroids in Leapfrog Geo and exported to Datamine Studio RM Pro.
Top-cutting was undertaken on composited samples, with each coded domain being
treated as a separate population. Top-cuts were applied to high Au, Cu and Co
grades following statistical and geospatial review.
Exploratory data analysis (EDA) was also undertaken on density data. The
amount of density data was not deemed sufficient to effectively estimate
density into the model given its spatial distribution within the modelled
domains. Density was therefore hard coded based on weathering state and
whether a domain was mineralised or waste. Default density values were derived
from the EDA analysis.
Variography was undertaken on grouped data that reflected the domains' spatial
position and orientation. Seven main mineralised domain areas were grouped,
with variography undertaken for each element (Au, Cu and Co) for a total of 21
variograms modelled. Variography was borrowed for domains deemed to be similar
in geometry and grade tenor.
Quantitative Kriging neighbourhood analysis (QKNA) was undertaken using
Snowden Supervisor software to assess several parameters i.e., block size,
estimation volume, sample numbers and discretisation points. This process was
undertaken for the 21 variograms. The cross-validation tool was used to
quantify how well a theoretical continuity model (variogram) was likely to
perform by comparing estimates produced using the model to the original sample
values.
A block model was built using a 20 m(E) x 20 m(N) x 10 m(RL) parent cell size
covering the full volume of the Greater Carlow deposit. Sub-celling was
permitted to 0.5 m in the X and Y directions and 1 m in the Z direction to
facilitate a high-resolution filling of the wireframes. The model was further
coded by weathering, using the same surfaces as the drillhole database.
Discretisation on a grid of 5 x 5 x 3 per parent cell was applied. A
three-pass search strategy was used. The first search extended to the full
range of the modelled variogram, the second pass was 1.5 times the range of
the first search using the sample minima and maxima as per the first search
listed above. The final and third pass used 3 times the range of the
variogram, halving the sample numbers defined in searches 1 and 2. Where
insufficient samples were available for small domains, search parameters were
changed on an individual domain basis. The maximum number of samples allowed
from any one drillhole was 3 or 4 and the number of samples used ranged from
6-12 to 12-24, depending on domain.
Estimation was by 3D Ordinary Kriging (OK) with dynamic anisotropy (DA)
enabled. Check estimates were carried out using OK without DA, and inverse
distance squared with DA enabled.
In comparison to the 2021 resource (refer to Artemis press release dated
20(th) May 2021), the 2022 resource is based on a higher-grade
width-constrained interpretation, which includes new drilling from 2021 and
2022. This is a change from the 2021 low-grade bulk volume interpretation. The
implication being a more selective mining approach for the 2022 resource. The
2021 and 2022 models are also therefore not directly comparable.
The resource estimate was classified in accordance with the Australasian Code
for Reporting of Exploration results, Mineral Resources and Ore Reserves (JORC
Code, 2012).
Reasonable Prospects for Eventual Economic Extraction (RPEEE) parameters
Pit optimisations were generated to constrain the Mineral Resource in the
context of Reasonable Prospects for Eventual Economic Extraction (RPEEE), as
required by the JORC Code. Whittle was used for the open pit resource and
Datamine MSO for the underground resource, as described below:
Open Pit
· Selective mining units have not been defined for open pit mining;
however, for the open pit a typical bench height approximates 5 m, with the
parent block being double that at 10 m in the Z direction.
Underground
· Sub-level long hole open stoping is the expected mining method and is
appropriate for the orebody widths and orientations.
· Stope dimensions were assumed to be 10 m along strike and 20 m between
levels.
· A minimum mining width of 1.5 m was applied, with 0.25 m dilution
applied on both the footwall and the hangingwall (thus the minimum mining
width of a diluted shape equates to 2.0 m).
Metallurgical factors
In 2019, ALS Metallurgy in Perth completed preliminary metallurgical testwork
on two drill core composite samples. The metallurgical testwork demonstrated a
potential Greater Carlow flowsheet utilising gravity and cyanide leach for
gold, and flotation to produce copper and cobalt concentrates.
Details are:
· 48% of the gold in testwork on metallurgical samples was recovered
using gravity separation, and most of the balance of the non-gravity gold is
recoverable in sulphide concentrates as a by-product, using standard
flotation. The total recovery of gold achieved was 94.8%.
· Quick floating copper minerals produced a high-grade copper
concentrate of approximately 30% Cu.
· Deleterious elements, including arsenic, could be managed with a
light concentrate polishing using regrind or blend control. Recoveries
depended on mineralogy, with 77-85% copper recoveries achieved.
· Unrecovered copper minerals are predominantly non-floating silicates
or secondary oxide copper minerals.
· Cobalt recoveries ranged from 73-79%. Saleable cobalt concentrate
grades ranging from 2.3-5.3% Co were produced. Cobaltite (CoAsS) is the
dominant cobalt bearing mineral, and is therefore intrinsically linked to
arsenic, affecting its refining route and ultimate sale price.
The mining and metallurgical factors used for the current resource estimate
are presented in Table 5.
Table 5. Mining and metallurgical factors used for RPEEE assumptions.
Parameter Input Value
Overall Slope Angles Oxide 40°
Transition 45°
Fresh 50°
Processing Cost AU$50 / t
Gold Recovery Oxide: 96%
Transitional: 93.5%
Fresh:93%
Copper Recovery Oxide: 61%
Transitional: 56%
Fresh: 90.5%
Cobalt Recovery Oxide: 47%
Transitional: 43%
Fresh: 78%
Mining Costs AU$2.70 / t +0.5c / t per m below 30 m RL, thereafter
add
Transitional AU$0.25 / t
and
Fresh AU$0.50 / t
NSRs (incl. payability, royalty and treatment and refining costs) Gold: 94%
Copper: 84%
Cobalt: 41%
Gold Price AU$2,600 / oz
Copper Price AU$12,699 / t
Cobalt Price AU$90,478 / t
Au Royalty (in dore) 2.5%
Au Royalty (in concentrate) 5%
Cu Royalty 5%
Co Royalty 5%
In the Competent Persons' opinion all elements have reasonable potential to be
recoverable and sold.
Gold Equivalent formula
The gold equivalent formula used in the calculation of an Au Eq. grade has the
following parameters:
Overburden/Oxide Au Eq. equation = Au (g/t) + Cu(%) x 0.86 + Co(%) x 2.31
Transitional Au Eq equation = Au (g/t) + Cu(%) x 0.81 + Co(%) x 2.17
Fresh Au Eq equation = Au (g/t) + Cu(%) x 1.31 + Co(%) x 3.96
It is the Competent Persons' view that all elements contributing to the gold
equivalent calculation have the potential to be extracted and sold.
Resource Classification
The Mineral Resource has been classified as Inferred. The classification level
is based upon assessment of geological understanding of the deposit,
geological and mineralisation continuity, drill spacing, QC results, search
and interpolation parameters, analysis of available density information and
current metallurgical test work.
COMPETENT PERSONS STATEMENT:
The information in this announcement that relates to Exploration Results and
Exploration Targets is based on information compiled or reviewed by Mr. Steve
Boda, who is a Member of the Australasian Institute Geoscientists. Mr. Boda
is an employee of Artemis Resources Limited. Mr. Boda has sufficient
experience that is relevant to the style of mineralisation and type of deposit
under consideration and to the activity 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'. Mr.
Boda consents to the inclusion in the announcement of the matters based on his
information in the form and context in which it appears.
This announcement was approved for release by the Board.
For further information on the Company, please visit
www.artemisresources.com.au (http://www.artemisresources.com.au) or contact:
Artemis Resources Limited via Camarco
Alastair Clayton
WH Ireland Limited
(Nominated Adviser and Broker)
Antonio Bossi / Megan Liddell (Corporate Finance) Tel: +44 20 7220 1666
Harry Ansell / Daniel Bristowe (Corporate Broking) Tel: +44 20 7220 1648
Camarco (Public Relations) Tel: +44 20 3781 9244
Gordon Poole / James Crothers Email: artemis@camarco.co.uk (mailto:artemis@camarco.co.uk)
Emily Hall / Rebecca Waterworth
About Artemis Resources
Artemis Resources (ASX: ARV; AIM: ARV, FRA: ATY; US: ARTTF) is an
Australian-based exploration and development company, led by an experienced
team that has a singular focus on delivering shareholder value from its
Pilbara gold projects - the Greater Carlow Gold Project in the West Pilbara
and the Paterson Central exploration project in the East Pilbara.
MAR
This announcement contains inside information for the purposes of Article 7 of
the UK version of Regulation (EU) No 596/2014 which is part of UK law by
virtue of the European Union (Withdrawal) Act 2018, as amended ("MAR"). Upon
the publication of this announcement via a Regulatory Information Service,
this inside information is now considered to be in the public domain.
JORC Code, 2012 Edition Table 1
JORC (2012) Table 1 - Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (e.g. cut channels, random chips, or · Both Reverse Circulation (RC) and diamond core has been used to
specific specialised industry standard measurement tools appropriate to the drill out the geological sequences and identify zones of mineralisation. RC
minerals under investigation, such as down hole gamma sondes, or handheld XRF samples comprised 58,261 m or 89% and HQ3 quarter (1,116: 33%) and half
instruments, etc.). These examples should not be taken as limiting the broad (3,685: 77%) core samples comprised 7,094 m or 11% of the total drilling at
meaning of sampling. Greater Carlow.
· Include reference to measures taken to ensure sample representivity · RC drilling was used to obtain one metre samples, using a 4.5"
and the appropriate calibration of any measurement tools or systems used. (112.5 mm) or 5.25" (131.2 mm) face sampling hammer. The entire RC sample was
extracted prior to subsampling at surface next to the rig. Field duplicates
· Aspects of the determination of mineralisation that are Material to were taken on selected intervals within the interpreted mineralised horizons.
the Public Report. Duplicates were collected at the rig from a static cone splitter, with the
primary and duplicate sample simultaneously collected from separate outlets.
· In cases where 'industry standard' work has been done this would be The cyclone was cleaned between rod changes to minimise contamination. Samples
relatively simple (e.g. 'reverse circulation drilling was used to obtain 1 m were collected via the rig-mounted cone splitter to yield sub-samples of
samples from which 3 kg was pulverised to produce a 30 g charge for fire approximately 3 kg per 1 m sample length. If any mineralised samples were
assay'). In other cases more explanation may be required, such as where there collected wet, they were noted in the drill logs and database. The rig
is coarse gold that has inherent sampling problems. Unusual commodities or splitter provided a primary sample of 20-30 kg, and a sub-sample of 2-4 kg for
mineralisation types (e.g. submarine nodules) may warrant disclosure of every metre drilled. RC sample recoveries were recorded by the geologist in
detailed information. the field during logging and sampling. If poor sample recovery was encountered
during drilling, the supervising geologist and driller endeavoured to rectify
the problem to ensure maximum and representative sample recovery. Visual
assessments for moisture and contamination were made by the field geologist.
Minor damp samples were encountered, with the field geologist and driller
ensuring the cleanliness of the cyclone and splitter. Sample recoveries during
the drilling completed by Artemis were high, with the average overall recovery
at 97%. All samples were dry.
· Diamond sampling techniques employed at the Artemis core facility
include saw cut HQ3 (63 mm) half drill core samples. Sample intervals for
diamond holes ranged from 0.3 m to 1.5 m, of which 97% are 1 m length.
Triple-tube HQ3 core drilling was completed to maximise diamond core
recoveries. For drilling in 2017 and 2018, diamond core was cut into two
quarters and one half using a core saw. One of the quarter core segments was
placed into a numbered calico bag, which was then tied and placed in a
plastic/polyweave bag. For drilling in 2020 and 2021, diamond core was cut in
half using a diamond core saw. One of the halves was placed into a numbered
calico bag, which was tied and placed in a plastic/polyweave bag. Drill core
sample recoveries were recorded by the geologist in the field during logging
and sampling. Core recoveries were calculated based on nominal run lengths
versus measured lengths of recovered core. Drill core recoveries during
drilling completed by Artemis were high, with average overall recovery for
diamond core 1 m samples at 97%.
Drilling techniques · Drill type (e.g. core, reverse circulation, open-hole hammer, rotary · Drillhole data comprised 65,355 m, consisting of 58,261 m of RC
air blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple and 7,094 m diamond holes. Holes were drilled by TopDrill, with RC by a
or standard tube, depth of diamond tails, face-sampling bit or other type, Schramm TD685 rig and diamond by an Evolution FH3000 rig.
whether core is oriented and if so, by what method, etc.).
· RC samples were collected using a face-sampling bit via the inner
return tube to a rig-mounted Sandvik cone splitter.
· All diamond core was collected by HQ3 sized triple-splitter core
barrels. Core was orientated by Reflex orientation tools.
Drill sample recovery · Method of recording and assessing core and chip sample recoveries and · The Competent Persons did not supervise previous drill programs;
results assessed. however Artemis have provided the following guidelines for drill sample
recovery which are considered as adequate.
· Measures taken to maximise sample recovery and ensure representative
nature of the samples. · Sample recoveries were recorded by the geologist in the field
during logging and sampling. Core recoveries were calculated based on nominal
· Whether a relationship exists between sample recovery and grade and run lengths versus measured length of recovered core.
whether sample bias may have occurred due to preferential loss/gain of
fine/coarse material. · If poor sample recovery was encountered during drilling, the
supervising geologist and driller endeavoured to rectify the problem to ensure
maximum and representative sample recovery.
· Visual assessments by a field geologist were made for moisture,
and possible contamination. Minor damp samples were encountered, and the field
geologist and driller ensured that the cleanliness of cyclone and splitter was
maintained.
· For RC drilling, a cyclone and static cone splitter were used to
ensure representative sampling and were routinely inspected and cleaned.
· Sample recoveries during drilling completed by Artemis were high,
with average recovery of 97% for DD and RC samples. Almost all samples were
dry.
· Triple-tube HQ3 core drilling was completed to maximise diamond
core recoveries. Diamond drilling was completed to assist in validating the
results from the RC samples; no identifiable bias was observed.
· No relationship exists between sample recovery and grade.
Logging · Whether core and chip samples have been geologically and · All RC and diamond drillholes were geologically logged to
geotechnically logged to a level of detail to support appropriate Mineral industry standards for the mineralisation present at the project.
Resource estimation, mining studies and metallurgical studies.
· All drill chip samples were geologically logged at 1 m intervals
· Whether logging is qualitative or quantitative in nature. Core (or from surface to the end of each drillhole.
costean, channel, etc.) photography.
· Diamond core was photographed, and RC chips were retained in chip
· The total length and percentage of the relevant intersections logged. trays for future reference.
· RC sample bags are placed in rows of 50 bags each. clear of the
rig. A field technician mixes the bag by hand before taking a sample using a
sieve and sieves the sample to remove fines. The sieved sample is then
transferred to a wet sieve in a bucket of water, and the sample is sieved
further until rock fragments are clearly visible. These rock fragments are
then logged by the site geologist, taking note of colour, grainsize, rock
type, alteration if any, mineralisation if any, veining if any, structural
information if notable and any other relevant information. This information is
then written down on pre-printed logging sheets, using codes to describe the
attributes of the geology. A representative sample is transferred to
pre-labelled chip trays into the corresponding depth from where the sample was
drilled from. The remainder of the sample from the sieve is then transferred
into a tray that has been marked up by depths at metre intervals. An
identification sheet noting the hole number and from-to depths that correspond
to each tray is then written up and placed above the tray and a photograph is
taken of the chips.
· The Competent Persons consider that the level of detail is
sufficient for the reporting of Mineral Resources. Logging data provides
information to support geological modelling, including weathering/oxidation
and water table surfaces and rock type.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all core · For drilling in 2017 and 2018 diamond core was cut into two
taken. quarters and one half using a diamond core saw. One of the quarters was placed
into a numbered calico bag, which was tied and placed in a plastic/polyweave
· If non-core, whether riffled, tube sampled, rotary split, etc. and bag.
whether sampled wet or dry.
· For drilling in 2020 and 2021 diamond core was cut in half using
· For all sample types, the nature, quality and appropriateness of the a diamond core saw. One of the halves was placed into a numbered calico bag,
sample preparation technique. which was tied and placed in a plastic/polyweave bag.
· Quality control procedures adopted for all sub-sampling stages to · RC samples were collected via a rig-mounted, Sandvik cone
maximise representivity of samples. splitter to yield sub-samples of approximately 3 kg per 1 m sample length. If
any mineralised samples were collected wet, they were noted in the drill logs
· Measures taken to ensure that the sampling is representative of the and database. The rig splitter provided a primary sample of 20-30 kg, and a
in-situ material collected, including for instance results for field sub-sample of 2-4 kg for every metre drilled.
duplicate/second-half sampling.
· Sample preparation consisted of drying, coarse crushing to c. 10
· Whether sample sizes are appropriate to the grain size of the mm, riffle splitting the 2-4 kg followed by pulverisation in an LM5 or
material being sampled. equivalent pulverising mill to a grind size of 85% passing 75 microns.
· QC procedures involve the insertion of Internal Reference
Materials (IRM), along with duplicates and blank samples. IRMs are based on
material with a local matrix matched composition which underwent a round-robin
process, involving five laboratories analysing 10 x 100 g pouches for Au, Cu
and Co. The insertion rate of each these was approximately 1 in 20. For RC and
diamond drilling, field duplicates were collected at the rig at a rate of c. 1
in 20. For RC drilling, field duplicates were taken on a routine basis at
approximately a 1:20 ratio using the same sampling techniques (i.e. cone
splitter) and inserted into the sample run.
· The Competent Persons consider the sampling, sample preparation
and assay methods are reasonable for the stage of the project and resource
classification; however, they are not optimised for coarse gold, which may be
present based on the observations of; (1) high RC field duplicate pair
precision of 51%; (2) the presence of occasional visible gold and (3)
metallurgical testwork which displays GRG values of up to 48%.
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and · A certified laboratory, ALS Chemex, was used for all analysis of
laboratory procedures used and whether the technique is considered partial or drill samples.
total.
· Sample preparation consisted of drying, coarse crushing to c. 10
· For geophysical tools, spectrometers, handheld XRF instruments, etc., mm, riffle splitting the 2-4 kg followed by pulverisation in an LM5 or
the parameters used in determining the analysis including instrument make and equivalent pulverising mill to a grind size of 85% passing 75 microns.
model, reading times, calibrations factors applied and their derivation, etc.
· This fraction was split again down to a 50 g charge for fire
· Nature of quality control procedures adopted (e.g. standards, blanks, assay (Au-AA26) with ICP finish.
duplicates, external laboratory checks) and whether acceptable levels of
accuracy (i.e. lack of bias) and precision have been established. · All samples were dried, crushed, pulverised, and split to produce
a sub-sample of 50 g which was digested in hydrofluoric, nitric, hydrochloric
and perchloric acid (4 acid digest). This digest is considered a total
dissolution for most minerals. Analysis was performed using ICP-OES finish
(ME-ICP61) for Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, La, Mg,
Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Sr, Th, Ti, Tl, U, V, W, Zn. Additional ore
grade ICP-OES finish (ME-OG62) was used for Cu reporting out of range.
· IRMs are matrix matched by using previous pulps from drilling
programs and homogenised using certified laboratories. Standards were analysed
by round robins to determine grade. Standards were routinely inserted into the
sample run at 1:20. Artemis inserted IRMs, of which 11 were used in the
Mineral Resource estimate. IRMs "18A" to "18F" and "A" to "F".
· RC and diamond field (quarter core) duplicates for 2021-2022
totalled 923 and 94, respectively. 1,010 IRMs and 171 blank samples were
inserted with routine samples at the rate of approximately one standard, blank
or duplicate in every 20 samples.
· Campaign-based analysis and reporting of quality control (QC)
data was undertaken of blanks, field duplicates, laboratory repeats,
laboratory blanks, repeats and IRMs in several groups of batches, and as a
project-wide group of all results.
· Laboratory internal duplicate checks (pulp duplicates) numbered
1,672, which represents duplication of 11% of the 2020 to 2022 dataset.
Repeatability between duplicate pairs was acceptable, though with a pairwise
precision of 22% which indicates a potential coarse gold content.
· IRMs for Au display bias between -5% to +9%. For the 2021-22
programme the key 18A-C IRMs are +8%, +6% and +9% respectively which is high
(expectation <5%). All IRM results for Cu and Co are <2% bias. The 3SD
failure rate for IRM Au is high, with values of >1% to 7.7% for 18A-D. For
Cu 18C-E are >1% and for Co 18A, C-E are >1%.
· The Competent Persons consider the sampling, sample preparation
and assay methods are reasonable for the stage of the project and resource
classification; however, they are not optimised for coarse gold, which may be
present based on the observations of; (1) high RC field duplicate precision of
51%; (2) the presence of occasional visible gold observed in core and RC
chips; and (3) metallurgical testwork which displays GRG (gravity recoverable
gold) values of 48%. The application of IRMs is not considered to be optimal,
and the use of commercial CRMs for future drilling is recommended.
Verification of sampling and assaying · The verification of significant intersections by either independent · Artemis geological staff collected and submitted all samples to
or alternative company personnel. the laboratory.
· The use of twinned holes. · The independent Competent Person, Ms Janice Graham, inspected RC
drilling residues and drill core during her site visit in May 2022.
· Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols. · The non-independent Competent Person, Dr Simon Dominy, inspected
limited drill core and observed RC residue bags during a site visit in
· Discuss any adjustment to assay data. November 2019. At this time, Dr Dominy was not a Director of Artemis.
· Diamond holes were drilled to infill areas of RC holes, and
diamond sample results showed moderate correlation to the nearest RC sample
results. A slight bias was observed for Au, Cu and Co in a comparison of RC
versus diamond assay grades.
· Electronic data capture is on MS Excel spreadsheets which are
then uploaded as .csv files and routinely sent to certified database
management provider.
· PDF laboratory certificates are stored on the server and are
checked by the Exploration Manager.
· No adjustments or calibrations have been made to any assay data.
· The Competent Persons consider that the information provided to
them by Artemis geological staff allows them to appropriately consider the
necessary factors in establishing Mineral Resources for the confidence
estimated.
Location of data points · Accuracy and quality of surveys used to locate drillholes (collar and · A Garmin GPSMap62 hand-held GPS was used to define the location
down-hole surveys), trenches, mine workings and other locations used in of the initial drillhole collars. Standard practice is for the GPS to be left
Mineral Resource estimation. at the site of the collar for a period of 5 minutes to obtain a steady
reading. Collar locations are accurate to within 5 m.
· Specification of the grid system used.
· All hole collars were surveyed by differential global positioning
· Quality and adequacy of topographic control. system (DGPS). The topographic surface was calculated from the onsite mine
survey pickups and subsequently verified by RTK GNSS collar surveys.
· Zone 50 (GDA 94) is the relevant grid. Surface collar coordinates
are surveyed via RTK GNSS with 1 cm accuracy by a professional surveying
contractor.
· Downhole locations were predominantly surveyed by gyroscope,
covering 95% of the total metres surveyed. Gyroscope values in the database
were recorded every 30 m, except in diamond hole 18CCAD001, and RC holes
ARC190 to ARC222 (inclusive) which include records every 10 m. Holes were also
surveyed by Reflex EZ TracTM down-hole camera.
· Another unknown method ("UNK") existed in the database for the
survey records of the collar of RC holes ARC033 and ARC105, and another record
of the latter at 66 m, both of which had no additional records. The maximum
depths of these holes were 22 m and 66 m. The survey data for ARC033 has been
derived from the planned hole azimuth and dip, and the survey data for ARC105
was derived from the DGPS collar survey measurement, which has been copied to
the maximum depth.
· Topographic data were captured in GDA94 MGA Zone 50 grid system.
A topographic surface was built from high-resolution 5 m Unmanned Aerial
Vehicle (UAV or drone) point data, with a resolution of 10 cm.
· The Competent Persons consider that the topographic control is
suitable to support the Mineral Resource estimate.
Data spacing and distribution · Data spacing for reporting of Exploration Results. · The mineralisation has been defined by two orthogonal drilling
grids to intersect the east-striking Carlow Main lodes and the north-striking
· Whether the data spacing, and distribution is sufficient to establish Quod Est lodes. The southern boundary of the Quod Est drilling grid adjoins
the degree of geological and grade continuity appropriate for the Mineral the northern boundary of the Carlow Main grid at its central-western area.
Resource and Ore Reserve estimation procedure(s) and classifications applied. Aside from minor mineralisation extensions, infill drillholes and several
interpretation-controlling scissor holes, drilling is regularly spaced 20 m
· Whether sample compositing has been applied. apart on 40 m spaced sections, nominally averaging -60° dips, and this has
provided consistent support to intersections of mineralisation and eliminated
any influence of hole angles on grade.
· Drillholes that define the Carlow Main mineralisation lie on 35
sections that shift north or south perpendicular to the sigmoidal curve that
defines the mineralisation trend. Drillholes in the western section of the
Carlow Main lodes have been drilled to the south to intersect the very steeply
north-dipping lodes, until section 507,640 mE, where the holes have been
drilled to the north to intersect the very steeply south-dipping lodes.
· Drilling into the Quod Est mineralisation has been intersected by
east-west orientated holes lying on eight sections - two of which are infill
sections - perpendicular to a central easting of 506,650 mE.
· Drilling into the Crosscut mineralisation has been intersected by
three sections with east-west orientated drillholes, two sections with
north-south orientated drillholes, and three sections with south-west
orientated drillholes.
· The downhole intervals logged by the geologist as being
mineralised or showing significant alteration were sampled and assayed at 1 m
intervals. Compositing of RC chip samples occurred for holes ARC036 to ARC081
only. All unmineralised intervals (based on the field portable XRF readings
for Cu, Co and As) were composited and assayed over 3 m intervals. Mineralised
intervals based on the field XRF readings were assayed in 1 m intervals.
· If a 3 m RC composite returned assays above normal background
levels, these intervals were re-sampled and assayed at 1 m intervals.
· The Competent Persons believe that the mineralised wireframes
have sufficient geological and grade continuity to support the classification
applied to the Mineral Resources given the current drill pattern.
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · The regularly-spaced drilling on consistent sections, and the
possible structures and the extent to which this is known, considering the orientations orthogonal to the strike of the lodes, have provided consistent
deposit type. support to intersections of mineralisation such as to minimise any bias or
influence of hole angles on grades.
· If the relationship between the drilling orientation and the
orientation of key mineralised structures is considered to have introduced a · No relationship has been noted between drillhole dip angle and
sampling bias, this should be assessed and reported if material. mineralisation.
· A positive bias has been noted for Au, Cu, and Co for drillholes
with azimuths oriented sub-parallel to mineralisation compared to similar
holes normal to mineralisation. The bias was limited to the eastern section of
Carlow Main and influence of high-grade sub-parallel drillholes on the
estimation controlled using a small volume wireframe.
Sample security · The measures taken to ensure sample security. · Samples were bagged, and cable tied upon collection. The chain of
custody was managed by the supervising geologist, who placed up to 10 calico
sample bags in polyweave sacks, clearly labelled with:
§ Artemis Resources Ltd
§ Address of laboratory
§ Sample range
· The polyweave sacks were then loaded directly into a bulka bag.
Each hole was placed in a separate bag, and twice a week the labelled bags
would be collected and delivered to a transport depot. These were then loaded
directly onto a truck and delivered direct to the laboratory. Each bulka bag
or hole had a separate sample dispatch, which became a separate analytical
batch at the laboratory.
· Sample security was maintained through short collection and
delivery turnarounds and the use of secured transport yards.
Audits or reviews · The results of any audits or reviews of sampling techniques and data. · No external audit of sampling techniques and data has been
undertaken.
· The Competent Persons strongly recommend that a study is undertaken
to optimise the Greater Carlow sampling protocols in the light of the
potential presence of coarse gold and relatively poor QC results.
JORC (2012) Table 1 - Section 2 Reporting of Exploration Results
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status · Type, reference name/number, location and ownership including · The project lies on tenement E47/1797-I, which is held by KML No.
agreements or material issues with third parties such as joint ventures, 2 Pty Ltd (KML), a 100% owned subsidiary of Artemis. The tenement was granted
partnerships, overriding royalties, native title interests, historical sites, on 07/05/2008 and is held in good standing.
wilderness or national park and environmental settings.
· According to the Department of Mines, Industry and Regulation
· The security of the tenure held at the time of reporting along with (DMIRS) of WA Mineral Titles Online system, the tenement has an excised
any known impediments to obtaining a licence to operate in the area. portion of land for the expired tenement M47/385 (DMIRS, 2019).
· The tenement is overlapped by a miscellaneous licence, granted
tenement L47/416 held conjointly by Stirling Bay Holdings and Swan Bay
Holdings.
· The tenement is securely held by a 100% owned subsidiary of
Artemis and there are no impediments preventing the operation of the Lease.
Exploration done by other parties · Acknowledgment and appraisal of exploration by other parties. Prior to its naming as Greater Carlow, the Project area was known first as
Cooper's.
Pre-1968
As early as the 1870s, copper ore was mined at the area formerly known as Glen
Roebourne. Gold was discovered in the district in the late 1880s and numerous,
small gold and gold-copper prospects, and minor silver, were worked to 1960.
In the 1930s, the area was investigated by North Australian Aerial Geological,
Geophysical Survey.
In 1964, Westfield Minerals NL undertook extensive regional mapping and
stream-soil sampling, and identified and drilled geochemical, magnetic and
induced polarisation (IP) anomalies.
The Geological Survey of Western Australia (GSWA) published a regional geology
map in 1965.
1968 - 1972
In 1968, Consolidated Gold Mining Areas NL drilled seven DD holes for 759 over
mining claims MC387 and MC410, which are now within E47/1797-I. The holes
intersected mineralisation containing three main chalcopyrite veins ranging
from 23 cm to 76 cm thickness and hosted up to 5.36% Cu, 17.14 g/t Au and
1.42% cobalt in separate 2 ft samples. Geophysical work was carried out to
improve mineralisation targeting included magnetometer, self- potential and IP
surveys.
In 1969, in partnership with Roebourne Exploration and Mining Ltd, Amax
commenced exploration of the area by 275 wide-spaced magnetometer survey lines
and 141 line- miles of IP survey, 2,800 ft of auger drilling, 14,000 ft of
percussion drilling, 2,800 ft of DD and 475 ft costean/trench. The details of
the exploration program completed are unclear, as the financing arrangements
only allowed for partial program completion. The trench revealed two vein
structures of high-grade mineralisation, with 8 m at 1.73% Cu and 14 m at 2.2%
Cu within a wide low-grade copper mineralisation halo grading 0.38% Cu that
contained numerous anomalous gold and cobalt results. However, Amax's primary
focus for the drilling program was targeting IP anomalies to the north of
Greater Carlow that were coincident with a chert band formed from a felsic
volcanic horizon that yielded 10 ft at 2.5% zinc. The target was a stratiform
zinc deposit, but instead the source of the IP anomalies was identified as
pyrite, and so Amax lost interest in the project area.
1986 - Openpit Mining Ltd
In a report for Artemis inserted into the annual report for the combined
reporting group to the GSWA, Torbinup Resources Pty Ltd noted that Openpit
Mining Ltd explored the known base metal mineralized areas for gold
mineralisation in 1986 and 1987, which included detailed mapping of the main
workings at Greater Carlow and the drilling of 31 RC holes for 1,527 m in the
Greater Carlow, Good Luck and Little Fortune areas (Cahill, 2011, cited in
Voermans, 2012). One hole, GC04, intercepted 22 m at 10.7 g/t Au below the No
1 Lode, which included a 6 m interval at 30.97 g/t Au.
1995 - 2008: Legend Mining Pty Ltd and others
The following has been taken from Cahill (2011), cited in Voermans (2012).
Legend commenced exploration of the area in 1995, initially concentrating on
areas of historic workings.
Dragon Mining NL, ("Dragon") and Titan Mining NL ("Titan") commissioned an
Airborne Electromagnetic ("AEM") survey over a large portion of the West
Pilbara in 1996 and 2001 respectively.
In 1999 and 2000, Legend explored the copper anomaly identified by AMAX in
1969, which led to the discovery of high-grade copper-gold mineralisation in a
soil covered area of Carlow South, south of the main workings.
Further field activities included RC drilling, soil geochemical sampling,
detailed ground magnetic surveys, trenching, preliminary metallurgical
testwork, gradient array induced polarization ("IP"), transient
electromagnetic ("TEM") surveys and resource estimates. This program was
successful in identifying a high-grade pod of gold mineralisation which
plunges 60° easterly within a broad shear zone and remains open at depth.
This pod is surrounded by an extensive halo of lower grade gold and copper
mineralisation over a strike length of 400 m which is open to the west.
In 2000 estimates of mineralisation within 100 m of the surface were produced
using a sectional polygonal method.
Several other prospects within a 500 m radius of the old Greater Carlow
workings were subject to first-pass RC drilling, and results confirm the
widespread presence of copper and gold mineralisation in the area.
Approximately 400 m east of the main workings, drillhole CC54 in Carlow East
intersected two mineralised horizons within a 20 m thick highly altered zone.
The intersections included 4 m grading 1.32% Cu and 4.55 g/t Au from 38 m, and
48 m 5.66% Cu and 1.87 g/t Au, which included 8 m at 0.16% Co.
Following orientation TEM and IP surveys over the Carlow South resource, a
detailed IP survey was completed over the main area of interest. A detailed
interpretation of the data resulted in the identification of numerous IP and
resistivity targets. A total of 28 IP targets and nine resistivity targets
were selected and assigned a follow-up priority for immediate drilling. This
planned drilling was never undertaken.
Small scale mining of the green chrysoprase was undertaken in the past on
M47/385 just north of the Greater Carlow main workings and several large
boulders were mined and subsequently cut and polished for marketing purposes.
Polished hand specimens show a translucent pattern of fine grained, apple
green colour chert, transected by milky- white to blackish quartz veins and
veinlets.
In 2007 and 2008, Legend undertook geophysical exploration surveys over the
project area, which used a combination of AEM and ground-based geophysics, and
consisted of:
· Compilation and processing of regional aeromagnetic and
radiometric datasets covering the entire the project area. The compilation
involved several historic datasets with line spacing varying from 25 m to 400
m.
· Three Versatile Time Domain Electromagnetic ("VTEM") surveys
covered an area of approximately 410 km(2), with flight directions ranging
from E-W to NW-SE to N-S depending on the orientation of stratigraphy. Line
spacing was either 200 m or 100 m with infill lines of 100 m or 50 m
respectively if conductive features of interest were identified.
· Three Ground Fixed-Loop Transient Electromagnetic ("FLTEM")
surveys were carried out to investigate 16 conductors identified by the
airborne VTEM surveys. Thirteen of the 16 VTEM targets surveyed identified
conductors considered significant enough to warrant future drill testing.
2008 - 2016:
No on ground exploration activities were conducted between 2008 and 2016 as a
native title agreement was being negotiated.
2017 - 2019:
Artemis commenced resource development drilling at Greater Carlow in 2017 with
81 RC holes for 7,357 m.
A sub-audio magnetic (SAM) survey over the Carlow South area in 2018 confirmed
the 1.2 km strike of the Greater Carlow Mineral Resource. Resource development
drilling in 2018 included 108 RC holes for 15,882 m, and 12 DD holes for 1,505
m. Drilling focussed on the Carlow South and Quod Est areas with drillholes
nominally spaced 20 m apart on 40 m spaced sections. The drilling results were
incorporated into mineral resource estimates in February 2019 and updated in
November 2019 and May 2021.
In 2019, ALS Metallurgy in Perth completed preliminary metallurgical testwork
on two 100 kg drill core composite samples. The metallurgical testwork
demonstrated a potential Greater Carlow ore flowsheet utilising gravity and
cyanide leach for gold, and flotation to produce copper and cobalt
concentrates.
2020 - 2022:
In 2020, Artemis completed follow-up resource development drilling at Greater
Carlow targeting infill and extensions at depth in the Main (East and West),
Quod Est and Crosscut areas. A total of 62 RC holes for 7,574 m and 11 DD
holes for 3,788 m were completed and successfully intersected mineralisation
up to 250 m below the November 2019
Mineral Resource.
Geology · Deposit type, geological setting and style of mineralisation. · The mineralisation system at Greater Carlow is currently
understood to represent a hydrothermal Cu-Co-Au system. Mineralisation is
hosted by sulphide-rich quartz-carbonate veins within a pervasively
chloritised shear zone of the Ruth Well Formation, consisting of mafic
volcano-sedimentary host rocks.
· The project area lies on Archaean volcanic arc rocks, which
overly two unconformable sequences of mainly volcanic and intrusive rocks.
Amphibolites and undifferentiated mafic and ultramafic rocks dominate the
older sequence, which have been metasomatised by intrusive activity. Gabbros
and calcrete-covered serpentinites have been recognised in the area.
· The Greater Carlow gold-copper-cobalt (Au-Cu-Co) deposit is
located 28 km northeast of the Radio Hill processing plant. Carlow Main and
Quod Est are structurally controlled mineralised zones occurring almost at
right angles to each other.
· The Quod Est portion strikes approximately north-south, dipping
steeply east with a strike length of about 200 m and is fault-terminated to
the north and potentially at depth.
· The Carlow Main portion strikes east-west, being fault disrupted
at each end. Drill definition has been completed over the 1,200 m strike
length which has a flattened sinusoidal form. At the western end
mineralisation dips steeply north; at the eastern end the mineralisation dips
steeply south. Mineralisation at Carlow Main has been shown to extend to at
least 550 m below surface.
· The Crosscut mineralisation strikes approximately north- south,
dipping steeply east, with a strike of about 150 m.
Drillhole Information · A summary of all information material to the understanding of the · Exploration results are not being reported in this Mineral Resource
exploration results including a tabulation of the following information for declaration.
all Material drillholes:
o easting and northing of the drillhole collar
o elevation or RL (Reduced Level - elevation above sea level in metres) of
the drillhole collar
o dip and azimuth of the hole
o down hole length and interception depth
o 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.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · Exploration results are not being reported.
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.
Relationship between mineralisation widths and intercept lengths · These relationships are particularly important in the reporting of · The bulk of the Carlow Main mineralisation lodes dip sub- vertically
Exploration Results. or steeply to the north and steeply to the south in the eastern 20%, while
Quod Est and Crosscut lodes dip steeply to the east. Other than a low
· If the geometry of the mineralisation with respect to the drillhole proportion of scissor holes that provided volume control, drillholes were
angle is known, its nature should be reported. angled near to 60° and with an azimuth perpendicular to the lodes strike to
provide as near a 'true' intercept thickness as realistically possibly.
· 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').
Diagrams · Appropriate maps and sections (with scales) and tabulations of · See the body of the release
intercepts should be included for any significant discovery being reported
These should include, but not be limited to a plan view of drillhole collar
locations and appropriate sectional views.
Balanced reporting · Exploration results are not being reported. · Exploration results are not being reported.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Surface geological observations have been incorporated into the
reported including (but not limited to): geological observations; geophysical geological interpretation and, in concert with the results of geochemical
survey results; geochemical survey results; bulk samples - size and method of assays, are considered reasonable for this style of mineralisation.
treatment; metallurgical test results; bulk density, groundwater, geotechnical
and rock characteristics; potential deleterious or contaminating substances.
Further work · The nature and scale of planned further work (e.g. tests for lateral · Infill drilling around the higher-grade zones is planned to improve
extensions or depth extensions or large-scale step-out drilling). the geological understanding of the host structures and the confidence of the
geological model, grade estimate and Mineral Resource classification in these
· Diagrams clearly highlighting the areas of possible extensions, zones.
including the main geological interpretations and future drilling areas,
provided this information is not commercially sensitive. · Metallurgical testwork samples are planned from the oxide,
transitional, and fresh weathering zones to optimise the process flowsheet and
allow accurate cutoff grades to be determined.
· Scoping-level studies are planned to increase the confidence in the
input parameters for an economic evaluation of the project.
JORC (2012) Table 1 - Section 3 Estimation and Reporting of Mineral Resources
Criteria JORC Code explanation Commentary
Database integrity · Measures taken to ensure that data has not been corrupted by, for · Artemis Resources is responsible for all primary data collection.
example, transcription or keying errors, between its initial collection and
its use for Mineral Resource estimation purposes. · Core/chip logging utilised project specific codes and was stored
using the database management system DataShed™. The software uses primary
key fields and look-up tables.
· Project specific validation rules and data integrity processes are
deemed adequate for database control of transcription or keying errors.
· Expedio, an external database partner, is responsible for loading and
exporting drillhole data. An accompanying PDF document is provided with each
database export detailing relevant changes and geologist accountable.
· Missing or incomplete data is flagged during export and is rectified
by site geologists.
· Validation errors and summary files were generated during the
drillhole database creation using output reports in Datamine Studio RM Pro
software.
· Data validation procedures used. · Snowden Optiro undertook a review of the database provided on 07
August 2022. No material flaws were identified, and the database was deemed of
sufficient quality to inform the October 2022 MRE.
Database integrity checks:
· Cut-off date and database file names
· Location plot of drillholes and collar elevation checks against high
resolution topographic surface
· Number of drillholes, hole type used
· Assay field and assay determination method
· Historical data review, suitability, and limitations of use
· Excluded drillholes and reasons
· Geological fields, and if used
· Treatment of below detection limit data and missing values
· All validation changes listed
· Survey method and visual validation for artificial drillhole traces.
Site visits · Comment on any site visits undertaken by the Competent Person and the · Geological staff from Artemis were responsible for the logging and
outcome of those visits. sampling of drill data from the Greater Carlow deposit.
· If no site visits have been undertaken indicate why this is the case. · The Snowden Optiro Competent Person, Ms Janice Graham, visited the
Greater Carlow deposit on 13 July 2022, observing the local geology, core
logging, drilling, and sampling practices of diamond and reverse circulation
(RC) programmes. The CP was shown example diamond core and RC chips from the
three main mineralised areas at Greater Carlow (Carlow Main, Crosscut and Quod
Est).
· The Artemis Competent Person, Dr Simon Dominy, visited the Greater
Carlow site in November 2019. Dr Dominy walked the Greater Carlow site and
viewed limited drill core at the Radio Hill site.
Geological interpretation · Confidence in (or conversely, the uncertainty of) the geological · The mineralisation system at Greater Carlow is currently understood
interpretation of the mineral deposit. to represent a hydrothermal Au-Cu-Co system. Mineralisation is hosted by
sulphide-rich quartz-carbonate veins within a pervasively chloritised shear
zone of the Ruth Well Formation, consisting of mafic volcano-sedimentary host
rocks.
· The Competent Persons are of the opinion that the geology of the
deposit and mineralisation model is sufficiently understood consummate to the
current drill spacing, data density and stage of the project.
· Nature of the data used and of any assumptions made. · All drillholes used in the interpretation and estimation are either
reverse circulation or diamond drill core. No assumptions have been made that
will affect the Mineral Resource estimate reported.
· The effect, if any, of alternative interpretations on Mineral · Alternative interpretations were presented and reviewed prior to the
Resource estimation. October 2022 geological interpretation. Snowden Optiro has worked closely with
Artemis Resources' technical team to create a mineralised model that reflects
the current understanding of the deposit based on structural and mineralogical
studies. Snowden Optiro is of the opinion that the current interpretation is
appropriate for the stage of the project and is globally reasonable. Further
drilling may lead to a change in the interpretation..
· The use of geology in guiding and controlling Mineral Resource · Geological modelling of mineralised system at Greater Carlow used a
estimation. 0.3% Cu and 0.5 g/t Au cut-off.
· At these cut-offs sufficient continuity is shown, allowing an
anastomosing vein system to be modelled. A broad 0.2% Cu halo can be
identified in the sample population, which is indicated visually and by
inflections in the copper log-probability plots.
· Structural data and logging of massive sulphide veins from diamond
core indicate that a hard-wireframed methodology appropriately represents the
underlying shoot geometry of the mineralisation. Existing research supports a
single mineralised system for all three elements modelled (Au-Cu-Co).
· The factors affecting continuity both of grade and geology. · The co-occurrence of Au-Cu-Co bearing minerals within the hypogene
and supergene show no evidence of successive overprinting phases of
mineralisation. This indicates that the ore fluid must have been capable of
simultaneously transporting these metals. As such Au, Cu and Co have been
domained together to represent a single, continuous, coincidental
mineralisation event. Sufficient continuity is achieved at the current drill
spacing to model continuous vein systems for Carlow Main, Crosscut and Quod
Est.
· Artemis Resources provided weathering surfaces for overburden, base
of complete oxidation, top of fresh rock and transitional zones
· Surfaces are modelled from regolith logging and geochemical data
notably that of sulphur ratios to Cu.
· The weathering surfaces are considered of moderate to high confidence
based on project stage and available data density.
Dimensions · The extent and variability of the Mineral Resource expressed as · The deposit is split into three areas, Carlow Main, Crosscut and Quod
length (along strike or otherwise), plan width, and depth below surface to the Est.
upper and lower limits of the Mineral Resource.
· Carlow Main is further split into three sub areas, east, west, and
far west, with mineralisation striking east-west with a broad sigmoidal shape
(approximating a 1.2 km strike). A southerly dip is exhibited in the east of
Carlow Main, with mineralisation modelled to a depth of approximately 600 m
below datum with appropriate drill support. The average depth of Carlow Main
mineralisation occurs to a depth of 240 m below datum. Towards the west dip
reverts to the north and repeated in the far west.
· Carlow Main is modelled as a series of veins with widths ranging from
0.3 m to 33 m
· Crosscut and Quod Est are orthogonal vein arrays located north of the
Carlow Main shear zone, striking north-south occurring as narrower vein array
(0.3 m-12 m) than that of Carlow Main. There is a general step down of veins
(representing distinct/individual pods) gradually increasing in depth to the
south. Crosscut is modelled to a depth of 300 m and Quod Est modelled to a
depth of 140 m below datum where drill support allows.
Estimation and modelling techniques · The nature and appropriateness of the estimation technique(s) applied · In comparison to the 2021 resource (refer to Artemis press release
and key assumptions, including treatment of extreme grade values, domaining, dated 20th May 2021), the 2022 resource is based on a higher-grade
interpolation parameters and maximum distance of extrapolation from data width-constrained interpretation, which includes new drilling from 2021 and
points. If a computer assisted estimation method was chosen include a 2022. This is a change from the 2021 low-grade bulk interpretation. The
description of computer software and parameters used. implication being a more selective mining approach for the 2022 resource. The
2021 and 2022 models are also therefore not directly comparable.
· Geological modelling of mineralised domains was undertaken in
Leapfrog Geo using the vein modelling tools.
· Separate mineralised vein domains were built from a merged table
using assay data. An interval selection table was derived from the merged
table to selectively code the drillholes to facilitate vein systems to be
built.
· The mineralised vein system utilised a lower guide cut-off of 0.3% Cu
and 0.5 g/t Au as determined from exploratory data analysis. Three separate
mineralised vein systems were created for Carlow Main, Crosscut and Quod Est.
· Carlow Main comprises 22 domains (1010-1220), Crosscut comprises six
domains (2010-2060) and Quod Est comprises three domains (3010-3030). The
wireframes can be considered hard-wireframed domains and are not derived from
grade shell interpolant process.
· A mineralised envelope was created using the distance to object
function, set at +25 m from the final vein merged systems, this represented
the approximate distance of a 0.2% Cu halo identified within the Greater
Carlow mineralised system. A separate mineralised halo was created for Carlow
Main (9990) and a combined halo for Crosscut and Quod Est (9980).
· Veins were visually checked for thickness, continuity, and extents.
Areas of extrapolation used half the drill spacing as a terminal distance.
Veins were checked for any unflagged drillholes to ensure no incorrect data is
inadvertently selected. If required veins were modified using control
polylines to prevent unrealistic volume extrapolation.
· Vein terminations were set to Boolean on the base of the topographic
surface.
· Vein relationships were assessed individually and a priority i.e.,
termination on adjacent domains set. Vein pinch outs and pinch outs around
drillhole were used where data supported this requirement.
· Wireframes were exported from Leapfrog Geo to Datamine Studio RM Pro
software for the purposes of data coding and estimation.
· Exploratory data analysis undertaken on coded drillholes using the
Snowden Supervisor software to understand density data distribution, boundary
analysis for weathering relationships, elemental correlation within modelled
domains and sample lengths.
· Samples were composited within domained surfaces (weathering and
domain boundaries) to 1 m representing the typical sample length of the data
at Greater Carlow. 97% of the sample data occurs within the 0.93 - 1.02 m
range.
· Weathering domains were coded to the mineralised domain intercepts
covering overburden, oxide, and transitional and fresh profiles.
· For the purposes of estimation overburden/oxide domains were
combined, and transitional/fresh domains combined based contact boundary
analysis. This is expected to honour the mineral speciation between the two
principal weathering domains
· A block model was built using a 20 m(E) by 20 m(N) by 10 m(RL) parent
cell size covering the full volume of the Greater Carlow deposit. Sub-celling
was permitted to 0.5 m X/Y directions and 1 m in the Z direction to facilitate
a high-resolution fill of the wireframes. The model was further coded by
weathering, using the same surfaces as the drillhole database.
· Dynamic Anisotropy, a process of locally rotating search orientation
with strike/dip and plunge of the domain was utilised and estimated into the
block model prior to grade estimation. The dip and dip direction were derived
from a central domain reference surface built from sample point centroids in
Leapfrog Geo and exported to Datamine Studio RM Pro. An isotropic search was
applied at 50 m by 50 m by 50 m ranges using 2-5 samples. The estimated
TRDIP/TRDIPDIR was visually validated against input data. TRPLUNGE was hard
coded into each domain based on variography modelling of direction of maximum
continuity. Rotations were checked by creating ellipses in Datamine Studio RM
Pro to ensure correct search rotations were being applied.
· Top-cutting was undertaken on composited samples, with each coded
domain being treated as a separate population. Top-cuts were applied to high
grades for Au, Cu and Co following statistical and geospatial review.
· Exploratory data analysis was undertaken on density data. Density
data was deemed insufficient to effectively estimate density into the model
given the spatial distribution within the modelled domains. Density was
elected to be hard coded based on weathering surface and whether a mineralised
domain or waste domain (country rock). Density data was derived from the EDA
analysis.
· Variography was undertaken on grouped data that reflected the domains
spatial position and orientation. Seven main mineralised domain areas were
grouped, with variography undertaken for each element (Au, Cu and Co) for a
total of 21 variograms modelled. Grouped estimation domains are listed below:
o Carlow Main East - 1013,1015,1023,1025,1033 and 1035
o Carlow Main West - 1043,1045,1053,1055,1063 and 1065
o Carlow Main Far West - 1073,1075,1083,1085,1093,1095
o Crosscut - 2015-2065
o Quod Est - 3015-3035
o Carlow Main Mineralised Waste - 9993 and 9995
o Crosscut/Quod Est Mineralised Waste - 9983 and 9995
· Variography was borrowed for domains deemed to be similar in geometry
and grade tenor.
· Quantitative Kriging neighbourhood analysis (QKNA) was undertaken
using the Snowden Supervisor software to assess several parameters i.e., block
size, sample pairs, discretisation points. This process was undertaken for the
twenty-one variograms. The cross-validation tool was used to understand how
well a theoretical continuity model (variogram) was likely to perform by
comparing estimates produced using the model to the original sample values. A
cross validation histogram was used to understand the estimated population
distribution against the histogram for composited estimation points (degree of
smoothing) A summary of each grouped domains QKNA is listed below:
o Carlow Main East (Au, Cu and Co) - 12-24, using a max key of four samples
per hole identifier
o Carlow Main West (Au, Cu and Co) - 12-24, using a max key of four samples
per hole identifier
o Carlow Main Far West (Au, Cu and Co) - 8-16, using a max key of four
samples per hole identifier
o Crosscut (Au, Cu and Co) - 8-16, using a max key of four samples per hole
identifier
o Quod Est (Au, Cu and Co) - 6-12, using a max key of three samples per hole
identifier
o Carlow Main Mineralised Waste (Au, Cu and Co) - 12-24, using a max key of
four samples per hole identifier
o Crosscut/Quod Est Mineralised Waste (Au, Cu and Co) - 12-24, using a max
key of four samples per hole identifier
· Discretisation was used nodes on grid of 5 by 5 by 3 m.
· A three-pass search strategy was used. The first distance to the full
range of the modelled variogram, the second pass, 1.5 times the range of the
first search using the sample pairs listed above. The final, third pass using
3 times the range of the variogram halving the sample numbers defined in
search 1 and 2.
· Where insufficient samples criteria were met for small domains,
search populations were changed for individual domains.
· Mineralised waste domains used a two-pass strategy, where if grade
was not estimated in pass 1 or 2, grade at half the detection limits was
assigned to absent grade blocks.
· Estimation utilised 3D Ordinary Kriging (OK) with dynamic anisotropy
(DA) enabled. Check estimates using OK without DA, and inverse distance
squared with DA enabled.
· The availability of check estimates, previous estimates and/or mine No production data is available as the deposit is unmined, bar some minor
production records and whether the Mineral Resource estimate takes appropriate historic workings, with no stated production figures.
account of such data.
Previous Mineral Resource estimates were available to the Competent Persons
for comparison. In comparison to the 2021 resource (refer to Artemis press
release dated 20th May 2021), the 2022 resource is based on a higher-grade
width-constrained interpretation, which includes new drilling from 2021 and
2022. This is a change from the 2021 low-grade bulk interpretation. The
implication being a more selective mining approach for the 2022 resource. The
2021 and 2022 models are also therefore not directly comparable.
2018
· Mr Philip Jones estimated an Inferred Mineral Resource for Carlow
South of 3.9 Mt at 0.9 g/t Au, 0.06% Co and 0.4% Cu using an inverse distance
cubed method (ID(3)). The estimate was reported above a 0.5 metal content,
where metal content defined using Au g/t + Cu% + Co ppm / 1,000. Drilling data
was provided by Artemis Resources to model mineralisation wireframes that were
based on a total net smelter return of >US$30 using the following metal
factors:
o Copper: prices - US$4.473/lb; recoveries - 75% (mining and metallurgical)
o Gold; price - US$1,282.10/oz; recoveries - 90% (mining and metallurgical)
o Cobalt: price - US$54,000/t; recoveries - 75% (mining and metallurgical)
2019
· January 2019, Al Maynard & Associates estimated an Inferred
Mineral Resource at Carlow South and Quod Est of 7.7 Mt at 0.51% Cu, 1.06 g/t
Au and 0.08% Co. Four domains were identified, based on strike of the
mineralisation. High-grade cuts were also applied using mean grades +2
standard deviations of copper, gold, and cobalt per domain. Grades were
interpolated by using inverse distance squared (ID(2)).
· November 2019, CSA Global estimated an Inferred Mineral Resource at
Carlow South and Quod Est of 8 Mt at 0.6% Cu, 1.6 g/t Au and 0.08% Co,
reported above a lower cut-off of 0.3% Cu, and within an optimised pit shell.
Two estimation domains for Carlow Main and Quod Est were used in the modelling
based on a lower cut-off grade of 500 ppm copper. Grade interpolation was
achieved initially by ordinary Kriging into panels, with post-processing using
localised uniform conditioning (LUC) within the panels to derive an estimate
at the smaller selective mining unit (SMU) scale. Grade limiting was employed
in the panel estimates to restrict the influence of extremely high grades to
10 m. The optimised pit shell for the Mineral Resource reporting used the
following parameters:
o 50° overall slope angle
o Oxide and Fresh used same recoveries/processing costs
o A$48.1/t processing cost
o 85% copper recovery
o 94.8% gold recovery
o 73% cobalt recovery
o Mining costs A$/t incremented by depth ranging from A$2.57 through to
A$5.77 inclusive
o Copper: A$9,000/t
o Gold: A$2,000/oz
o Cobalt: A$48,000/t
2021
· May 2021, CSA Global estimated an Inferred Mineral Resource at
Greater Carlow Main, Crosscut and Quod Est of 14.3 Mt at 1.4 g/t Au Eq., 0.7
g/t Au, 0.4% Cu and 0.05% Co within an optimised pit shell. Geological
modelling utilised Leapfrog Geo to generate estimation domains by indicator
interpolants at a nominal 200 ppm/500 ppm Cu and 0.5 g/t Au cut-offs. 9
estimation domains resulted with a corresponding minzon code, listed below:
o Carlow Main (minzon 10 - low-grade zone - Cu, Co ± Au, minzon 11 -
high-grade zone - Au, Cu and Co, minzon 12 - very high-grade zone - Au, Cu and
Co)
o Quod Est (minzon 20 - low-grade - Cu, Co ± Au, minzon 21 - high-grade
zone Au, Cu and Co)
o Crosscut (minzon 30 - low-grade Cu, Co ± Au, minzon 31 - low-grade zone -
Au, Cu and Co, minezon 32 - Low-grade zone - Cu, Co ± Au and minzon 33 - Au,
Cu, Co)
· High-grade cuts were used to constrain high grades in the dataset.
· Grade interpolation for gold, copper, cobalt, arsenic, and sulphur
was completed using ordinary Kriging (OK) using dynamic anisotropy. Low-grade
minzon domains (10,20,30 and 32) were estimated using indicator Kriging based
on a single 0.1 g/t Au indicator, the resulting Kriged indicator was
multiplied by 0.6 g/t Au to get the final block estimate grade.
· Acid soluble copper variable Cu_Spct (sulphuric acid soluble),
Cu_Cpct (cyanide soluble), Cu_Rpct (residual copper), were estimated using
inverse distance squared (ID(2)) with a two-pass search ellipse strategy.
· An open pit optimisation undertaken using Whittle software and
assumed the following parameters:
o 50° overall slope angle
o Oxide, transitional and fresh use same recoveries and processing costs
o Processing costs of A$48.1/t (includes refining, insurance and general and
administration).
o Recoveries, which in Artemis' opinion have a reasonable potential to be
achieved of; 94.8% gold recovery, 85% copper recovery and 73% cobalt recovery.
o Mining costs A$/t incremented by depth, ranging from A$2.57/t through to
A$6.35 inclusive.
o Commodity prices (A$) Gold - A$2,200/oz, copper A$9,400/t and cobalt
A$50,000t.
o Royalties per tonne payable on both copper and cobalt produced of 5%. Gold
royalty of 2.5% per ounce produced.
o Mineral Resource reported above a 0.3 g/t gold equivalent, and calculated
by a weighted average of the three components of gold, copper, and cobalt,
using the same commodity prices and metallurgical recoveries as the
optimisation
o AuEq equation - Au (g/t) + ((Cu (%) x ((Cu$/t x Cu recovery x 0.01) / (Au
$/g x Au recovery)) + (Co (%) x ((Co $/t x Co recovery x 0.01) / (Au $/g x Au
recovery)).
· The assumptions made regarding recovery of by-products. · Mineralised domains were modelled using a combined 0.3% copper
cut-off and 0.5 g/t gold cut-off. Cobalt is constrained to this domain
demonstrating sufficient correlation with copper and gold.
· Gold can be recovered via gravity, prior to subsequent floatation for
the copper. It is reasonable to expect residual gold may be recovered by
conventional cyanide leach finish.
· Testwork for copper and cobalt demonstrate recovery via sequential
floatation.
· Estimation of deleterious elements or other non-grade variables of · Three elements were estimated Au-Cu-Co.
economic significance (e.g., sulphur for acid mine drainage characterisation).
· Arsenic and sulphur have not been estimated at this stage, and
further work is required to evaluate their impact on the project.
· In the case of block model interpolation, the block size in relation · The dimensions of the block model selected represent the half the
to the average sample spacing and the search employed. typical drill spacing as 40 m along strike and 20 m down-dip. Sub-celling was
permitted to 0.5 m (X) by 0.5 m (Y) and 1 m (Z) to provide a suitable volume
fill consummate to the drill spacing and selectivity.
· Block size was determined and validated using QKNA review observing
slope of regression and kriging efficiencies, by moving the centroid of the
block to different data densities.
· Estimations used a three-pass strategy, whereby the first search
reflected the maximum modelled continuity, the second pass used 1.5 times the
maximum modelled continuity and third pass was three times the primary ranges.
· Detailed sample pairs are listed in Estimation and Modelling
Techniques (Table 1, Section 3).
· Resource classification has considered search volume as part of the
resource classification process.
· Any assumptions behind modelling of selective mining units. Open Pit
· Selective mining units have not been defined for open pit mining,
however, for the open pit a typical bench height approximates 5 m, with the
parent block being double that at 10 m in the Z direction.
Underground
· Sub-level long hole open stoping is an expected mining method
appropriate for the ore body widths and dip.
· Stope dimensions utilised a strike of 10 m and a 20 m dip.
· Minimum mining width of 1.5 m with 0.25 m dilution on both FW and HW
(minimum mining width of a diluted shape equates to 2.5 m).
· Any assumptions about correlation between variables. · A good correlation is shown for the primary elements Au-Cu-Co within
the modelled domains. The three elements are modelled in the same mineralised
domains. The estimation method has not specifically built in the correlation
and the elements have been estimated independently. Pearsons correlation
coefficients for the three elements are shown below:
Element Au_ppm Cu_ppm Co_ppm
Au_ppm 1 0.66 0.67
Cu_ppm 0.66 1 2
Co_ppm 0.67 0.45 1
· Description of how the geological interpretation was used to control · Modelling of the mineralised domains utilised available data provided
the resource estimates. to Snowden Optiro including logged geology and structural data available on
diamond core.
· Domains are considered hard wireframed with estimation taking place
within a final derived estimation field grouped by weathering.
· The mineralised envelope utilised a hard top-cutting approach of the
sample population to avoid material flagging as economic in non-hard
wireframed constrained areas. The mineralised envelope correlated well with a
broad lower 0.2% copper halo that surrounded the primary mineralised domains
and a stoped out by the mineralisation, therefore no double counting of blocks
can occur.
· Discussion of basis for using or not using grade cutting or capping. · A top-cutting methodology was used and undertaken on a
domain-by-domain basis for Au, Cu and Co. Top-cuts were selectively chosen via
statistical review along with a geospatial review of their location, with the
likely effect of their influence on metal contribution considered. Where high
grades were identified, populations were trimmed or cut back to an expected
high-grade value.
· The process of validation, the checking process used, the comparison · Models were validated using tonnage weighted output grades against
of model data to drillhole data, and use of reconciliation data if available. equal weighted mean grades and declustered top-cut sample grades. Models were
subjected to visual interrogation against input data for response to grade
changes both in plan, section and globally. Further validation utilised swath
plot analysis to understand model responsiveness to underlying data support to
determine areas of extrapolation over interpolation.
· Domains were ranked in order of metal contribution to the Greater
Carlow project for materiality to the estimation.
· Domains that were to be split by resource classification, were
validated using Inferred Resources solely, excluding extrapolated unclassified
resources.
Moisture · Whether the tonnages are estimated on a dry basis or with natural · Tonnages have been estimated on a dry basis.
moisture, and the method of determination of the moisture content.
Cut-off parameters · The basis of the adopted cut-off grade(s) or quality parameters Mineral Resources were reported separately for the open pit and underground
applied. using an Au Eq. calculation. Au Eq. factors include payability and downstream
costs (NSR). The global Au Eq. formula follows, and includes payability and
downstream costs:
Au Eq. = Au (g/t) + (Cu (%) x (Cu(NSR A$/t) / Au(NSR A$/t))) + (Co (%) x
(Co(NSR A$/t) / Au(NSR A$/t)))
The Table below summarises the inputs into the above equation for Au Eq.
The calculation was determined for each weathering interface using the
following formula (refer Table above)[Au Eq. = g/t]:
· Oxide: Au Eq. = Au(g/t) + ((Cu%) x 0.86)) + (Co%) x 2.31))
o Recovery of 96.0% gold, 61.0% copper and 47.0% cobalt
· Transitional: Au Eq. = Au(g/t) + ((Cu%) x 0.81)) + (Co%) x 2.17))
o Recovery of 93.5% gold, 56.0% copper and 43.0% cobalt
· Fresh: Au Eq. = Au(g/t) + ((Cu%) x 1.31)) + (Co%) x 3.96))
o Recovery of 93.0% gold, 90.5% copper and 78.0% cobalt
Open pit - OP cut-off grade - 0.70 g/t Au Eq.
OXIDE
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
TRANSITIONAL
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
FRESH
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· NSR: A$66.64/t
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
Underground cut-off grade - 2.00 g/t Au Eq.
FRESH
· Mining cost: A$80/t
· Processing cost: A$50.00/t
· Mining dilution: 10%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
Mining factors or assumptions · Assumptions made regarding possible mining methods, minimum mining · Open pit mining is considered as the appropriate mining method for
dimensions and internal (or, if applicable, external) mining dilution. It is future studies with an underground reported below the optimised pit outline.
always necessary as part of the process of determining reasonable prospects The Competent Persons believe that there are Reasonable Prospects for Eventual
for eventual economic extraction to consider potential mining methods, but the Economic Extraction based on the outputs of the Whittle™ and MSO
assumptions made regarding mining methods and parameters when estimating optimisations.
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.
Open pit optimisation parameters
Modifying factors:
· Slope angles:
o Overburden/oxide: 40°
o Transitional: 45°
o Fresh: 50°
· Dilution: 5%
· Mining recovery: 95%
· Processing recovery:
o Gold overburden/oxide: 96.0%
o Gold transitional: 93.5%
o Gold fresh:93.0%
o Copper overburden/oxide: 61.0%
o Copper transitional: 56.0%
o Copper fresh: 90.5%
o Cobalt overburden/oxide: 47.0%
o Cobalt transitional: 43.0%
o Cobalt fresh: 78.0%
Revenue factors:
· Gold price: $A2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR (including payability, royalty, and transport/refining costs)
o Au 94.0%
o Cu 84.0%
o Co 41.0%
Costs:
· Mining cost: A$2.70 +5c/m depth, below 30mRL/rock transitional -
A$0.25/t and fresh - A$0.5/t
· Processing costs: A$50.00/t
Royalties:
· Gold - 2.5% (in dore)
· Gold - 5% (in concentrate)
· Copper - 5%
Underground optimisation parameters
· The Datamine Mining Stope Optimiser (MSO) was run over Inferred
Resource below the optimised pit.
· MSO shapes were removed if they occurred in isolation or presented a
low likelihood of eventual economic extraction.
MSO parameters:
· Evaluation field: Au Eq.
· Au Eq. cut-off grade: >=2.00 g/t
· Minimum mining width of 1.5 m with 0.25 m HW and FW dilution (2.0 m)
minimum diluted stope shape
· Stope geometry run for XZ (E-W) strike 10 m x dip 20 m - Carlow Main
· Stope geometry run for YZ (N-S) strike 10 m x dip 20 m - Crosscut and
Quod Est
· Orebody wireframe used as a control surface
· Strike max change of 20°
· Vertical side length ratio 1.5 (front/back and top/bottom)
· Stope waste dilution maximum permittable: 80%
Metallurgical factors or assumptions · The basis for assumptions or predictions regarding metallurgical · Chemech Consulting were engaged to undertake a preliminary
amenability. It is always necessary as part of the process of determining metallurgical review of the Greater Carlow deposit (July 2022). A summary of
reasonable prospects for eventual economic extraction to consider potential the findings is documented below:
metallurgical methods, but the assumptions regarding metallurgical treatment
processes and parameters made when reporting Mineral Resources may not always · Three testwork programmes have been undertaken on the Greater Carlow
be rigorous. Where this is the case, this should be reported with an deposit, two programmes using RC chips to generate three samples from three
explanation of the basis of the metallurgical assumptions made. drillholes. The second using diamond to create two composite samples from
twelve drillholes. This data has been used to develop the flowsheet and
predict metallurgical performance (grade and recoveries).
· Testwork identified a flowsheet that includes a gravity gold circuit,
followed by sulphide flotation (producing a separate copper/gold concentrate)
· Concentration circuits include separate cleaning circuits with
regrinding.
· Cyanide leach of the flotation tail to recover residual gold.
· Preliminary metallurgical testwork was conducted by ALS Metallurgy in
2019 results are present below:
Gold
· 48% recovery of gold by using gravity separation. The remaining
balance of non-gravity gold is recoverable in sulphide concentrates as a
by-product of standard flotation or via CIL scavenging.
Copper
· Quick floating copper minerals produced a high-grade copper
concentrate of approximately 30% Cu. Deleterious elements including arsenic
may be managed with a light concentrate polishing using regrind or blend
control. Recoveries depending on mineralogy, with 77-85% copper recoveries
achieved. Unrecovered copper minerals are represented by non-floating
silicates or secondary oxide copper minerals.
Cobalt
· Cobalt recoveries ranged from 73-79%. Potentially saleable cobalt
concentrate grades ranging between 2.3-5.3% Co were produced. Cobaltite
(CoAsS) is the dominant cobalt-bearing mineral and therefore intrinsically
linked to arsenic affecting its sale price. Given the potentially low-grade
nature of the Co concentrate, Artemis believe that the route to Co
monetization could include: (1) concentrate sale for blending into a
higher-grade feed thus ameliorating the low Co and high As content; (2)
potential route via oxidative hydrometallurgy involving concentrate roasting,
acid leaching and solvent extraction to form a Co salt; or (3) via some other
innovative leaching technique.
· Full and further testwork and evaluation is required to resolve the
monetization of Co at Greater Carlow.
Future Work
· It is recommended that additional metallurgical testwork be
undertaken to understand how individual comminution and metallurgical
responses may differ through the weathered zones for each proposed ore zone.
· Further metallurgical drilling at an approximate 50 m to 100 m
spacing along strike of the deposit within the optimised pit shell.
Environmental factors or assumptions · Assumptions made regarding possible waste and process residue · No assumptions regarding waste and process residue disposal have been
disposal options. It is always necessary as part of the process of determining made.
reasonable prospects for eventual economic extraction to consider the
potential environmental impacts of the mining and processing operation. While · No assumptions of arsenic or sulphur have been made at this stage of
at this stage the determination of potential environmental impacts, the project.
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.
Bulk density · Whether assumed or determined. If assumed, the basis for the · There was insufficient density data per domain to accurately estimate
assumptions. If determined, the method used, whether wet or dry, the frequency density.
of the measurements, the nature, size and representativeness of the samples.
· Density was hard coded based on exploratory data analysis, comparison
to previous studies and empirical data density values.
· Bulk density data was derived from either downhole geophysical gamma
density or from core using water immersion on HQ3 core.
· Good correlation of density between gamma density and diamond density
determinations is recorded.
· Bulk density data was coded into the block model based on weathering
and mineralised domain. A summary of the values used is shown below:
Domain Weathering Bulk density assigned (t/m3)
Mineralised overburden Overburden 1.94
Mineralised oxide Oxide 2.51
Mineralised transitional Transitional 2.73
Mineralised fresh Fresh 2.88
Country rock overburden Overburden 1.94
Country rock oxide Oxide 2.43
Country rock trans Transitional 2.75
Country rock fresh Fresh 2.86
· The bulk density for bulk material must have been measured by methods · Gamma density is a quantitative, in-situ measurement of density that
that adequately account for void spaces (vugs, porosity, etc.), moisture and accounts for void spaces. The measurements have been calibrated to regular
differences between rock and alteration zones within the deposit. calibration holes in the iron ore deposits of the Pilbara, and on material at
the contractors' facilities.
· The water immersion method measurements were determined by measuring
the weight of part or the entire sample in air and water and then applying the
formula bulk density = weight (air)/ weight (air) - weight (water).
· Samples of drill core were sealed with masonry sealant/wax and
allowed to dry prior to bulk density determination.
· Discuss assumptions for bulk density estimates used in the evaluation · The gamma density data were considered sufficient in number for all
process of the different materials. material types, quantitative and unbiased.
· Calibration was undertaken using comparison to other holes and to
density measured by water immersion.
· Density values assigned are robust considering the stage of the
project and consummate resource classification.
Classification · The basis for the classification of the Mineral Resources into · The Greater Carlow deposit is classified as an Inferred Mineral
varying confidence categories. Resource. The cut-off boundary for Inferred to unclassified has been
determined based on estimation quality parameters, drill spacing, estimation
search pass, extrapolation, and qualitative risk in the underlying geological
interpretation. The classification also takes into consideration the level of
geological knowledge of the deposit, density data coverage, soluble/insoluble
copper speciation and sampling/assaying protocols.
· Whether appropriate account has been taken of all relevant factors · The classification reflects the overall confidence in the Greater
(i.e., relative confidence in tonnage/grade estimations, reliability of input Carlow deposit based on observed continuity at the current drill spacing.
data, confidence in continuity of geology and metal values, quality, quantity,
and distribution of the data). · Continuity is consistent at the current drill spacing and
orientation.
· Whether the result appropriately reflects the Competent Person's view · The Inferred Mineral Resource results are in line with expectations
of the deposit. of the Competent Persons.
· The Inferred Mineral Resource has been reported within an optimised
pit shell and the underground resource constrained to a Mining Stope Optimiser
(MSO) run, indicating reasonable prospects of eventual economic extraction.
· The Inferred Mineral Resource statement is in line with prior MRE
estimations, notably grade and contained ounces.
Audits or reviews · The results of any audits or reviews of Mineral Resource estimates. · The MRE has been peer reviewed as part of Snowden Optiro standard
internal peer review process by Mr. Ian Glacken FAusIMM(CP) FAIG MIMMM(CEng).
Covering, but not exclusive to geological interpretation of mineralised
domains, domain coding and compositing, top-cuts, estimation
method/suitability and input parameters to the resultant estimate.
· Snowden Optiro and Artemis have applied RPEEE factors to the
Reportable Resource via the use of a Whittle Shell and MSO.
· No reviews external to Snowden Optiro or Artemis have been undertaken
on this Mineral Resource estimate.
Discussion of relative accuracy/ confidence · Where appropriate a statement of the relative accuracy and confidence · The relative accuracy of the Greater Carlow Mineral Resource Estimate
level in the Mineral Resource estimate using an approach or procedure deemed is reflected in the reporting of the Mineral Resource as per the guidelines of
appropriate by the Competent Person. For example, the application of the 2012 JORC Code.
statistical or geostatistical procedures to quantify the relative accuracy of
the resource within stated confidence limits, or, if such an approach is not · The Mineral Resource was validated against the input composite data.
deemed appropriate, a qualitative discussion of the factors that could affect
the relative accuracy and confidence of the estimate. · The statement relates to a global estimate of tonnes and grade by
combining Reportable Resource within the optimised open pit cut-off utilising
a cut-off 0.7 g/t Au Eq. and MSO constrained underground resource reported at
a cut-off 2 g/t Au Eq.
· The statement should specify whether it relates to global or local · Confidence in the Mineral Resource estimate is consummate to guidance
estimates, and, if local, state the relevant tonnages, which should be in the JORC Code 2012.
relevant to technical and economic evaluation. Documentation should include
assumptions made and the procedures used. · The Mineral Resource statement relates to a global estimate of
in-situ tonnes and grade.
· These statements of relative accuracy and confidence of the estimate · No production data is available for comparison.
should be compared with production data, where available.
· Description of how the geological interpretation was used to control
the resource estimates.
· Modelling of the mineralised domains utilised available data provided
to Snowden Optiro including logged geology and structural data available on
diamond core.
· Domains are considered hard wireframed with estimation taking place
within a final derived estimation field grouped by weathering.
· The mineralised envelope utilised a hard top-cutting approach of the
sample population to avoid material flagging as economic in non-hard
wireframed constrained areas. The mineralised envelope correlated well with a
broad lower 0.2% copper halo that surrounded the primary mineralised domains
and a stoped out by the mineralisation, therefore no double counting of blocks
can occur.
· Discussion of basis for using or not using grade cutting or capping.
· A top-cutting methodology was used and undertaken on a
domain-by-domain basis for Au, Cu and Co. Top-cuts were selectively chosen via
statistical review along with a geospatial review of their location, with the
likely effect of their influence on metal contribution considered. Where high
grades were identified, populations were trimmed or cut back to an expected
high-grade value.
· The process of validation, the checking process used, the comparison
of model data to drillhole data, and use of reconciliation data if available.
· Models were validated using tonnage weighted output grades against
equal weighted mean grades and declustered top-cut sample grades. Models were
subjected to visual interrogation against input data for response to grade
changes both in plan, section and globally. Further validation utilised swath
plot analysis to understand model responsiveness to underlying data support to
determine areas of extrapolation over interpolation.
· Domains were ranked in order of metal contribution to the Greater
Carlow project for materiality to the estimation.
· Domains that were to be split by resource classification, were
validated using Inferred Resources solely, excluding extrapolated unclassified
resources.
Moisture
· Whether the tonnages are estimated on a dry basis or with natural
moisture, and the method of determination of the moisture content.
· Tonnages have been estimated on a dry basis.
Cut-off parameters
· The basis of the adopted cut-off grade(s) or quality parameters
applied.
Mineral Resources were reported separately for the open pit and underground
using an Au Eq. calculation. Au Eq. factors include payability and downstream
costs (NSR). The global Au Eq. formula follows, and includes payability and
downstream costs:
Au Eq. = Au (g/t) + (Cu (%) x (Cu(NSR A$/t) / Au(NSR A$/t))) + (Co (%) x
(Co(NSR A$/t) / Au(NSR A$/t)))
The Table below summarises the inputs into the above equation for Au Eq.
The calculation was determined for each weathering interface using the
following formula (refer Table above)[Au Eq. = g/t]:
· Oxide: Au Eq. = Au(g/t) + ((Cu%) x 0.86)) + (Co%) x 2.31))
o Recovery of 96.0% gold, 61.0% copper and 47.0% cobalt
· Transitional: Au Eq. = Au(g/t) + ((Cu%) x 0.81)) + (Co%) x 2.17))
o Recovery of 93.5% gold, 56.0% copper and 43.0% cobalt
· Fresh: Au Eq. = Au(g/t) + ((Cu%) x 1.31)) + (Co%) x 3.96))
o Recovery of 93.0% gold, 90.5% copper and 78.0% cobalt
Open pit - OP cut-off grade - 0.70 g/t Au Eq.
OXIDE
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
TRANSITIONAL
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
FRESH
· Processing cost: A$50.00/t
· Mining dilution: 5%
· Gold royalty: 2.5%, copper royalty: 5%
· NSR: A$66.64/t
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
Underground cut-off grade - 2.00 g/t Au Eq.
FRESH
· Mining cost: A$80/t
· Processing cost: A$50.00/t
· Mining dilution: 10%
· Gold royalty: 2.5%, copper royalty: 5%
· Gold price: A$2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR: Au - 94.0% Cu - 84.0%, Co - 41.0%
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.
· Open pit mining is considered as the appropriate mining method for
future studies with an underground reported below the optimised pit outline.
The Competent Persons believe that there are Reasonable Prospects for Eventual
Economic Extraction based on the outputs of the Whittle™ and MSO
optimisations.
Open pit optimisation parameters
Modifying factors:
· Slope angles:
o Overburden/oxide: 40°
o Transitional: 45°
o Fresh: 50°
· Dilution: 5%
· Mining recovery: 95%
· Processing recovery:
o Gold overburden/oxide: 96.0%
o Gold transitional: 93.5%
o Gold fresh:93.0%
o Copper overburden/oxide: 61.0%
o Copper transitional: 56.0%
o Copper fresh: 90.5%
o Cobalt overburden/oxide: 47.0%
o Cobalt transitional: 43.0%
o Cobalt fresh: 78.0%
Revenue factors:
· Gold price: $A2,600/oz
· Copper price: A$12,699/t
· Cobalt price: A$90,478/t
· NSR (including payability, royalty, and transport/refining costs)
o Au 94.0%
o Cu 84.0%
o Co 41.0%
Costs:
· Mining cost: A$2.70 +5c/m depth, below 30mRL/rock transitional -
A$0.25/t and fresh - A$0.5/t
· Processing costs: A$50.00/t
Royalties:
· Gold - 2.5% (in dore)
· Gold - 5% (in concentrate)
· Copper - 5%
Underground optimisation parameters
· The Datamine Mining Stope Optimiser (MSO) was run over Inferred
Resource below the optimised pit.
· MSO shapes were removed if they occurred in isolation or presented a
low likelihood of eventual economic extraction.
MSO parameters:
· Evaluation field: Au Eq.
· Au Eq. cut-off grade: >=2.00 g/t
· Minimum mining width of 1.5 m with 0.25 m HW and FW dilution (2.0 m)
minimum diluted stope shape
· Stope geometry run for XZ (E-W) strike 10 m x dip 20 m - Carlow Main
· Stope geometry run for YZ (N-S) strike 10 m x dip 20 m - Crosscut and
Quod Est
· Orebody wireframe used as a control surface
· Strike max change of 20°
· Vertical side length ratio 1.5 (front/back and top/bottom)
· Stope waste dilution maximum permittable: 80%
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.
· Chemech Consulting were engaged to undertake a preliminary
metallurgical review of the Greater Carlow deposit (July 2022). A summary of
the findings is documented below:
· Three testwork programmes have been undertaken on the Greater Carlow
deposit, two programmes using RC chips to generate three samples from three
drillholes. The second using diamond to create two composite samples from
twelve drillholes. This data has been used to develop the flowsheet and
predict metallurgical performance (grade and recoveries).
· Testwork identified a flowsheet that includes a gravity gold circuit,
followed by sulphide flotation (producing a separate copper/gold concentrate)
· Concentration circuits include separate cleaning circuits with
regrinding.
· Cyanide leach of the flotation tail to recover residual gold.
· Preliminary metallurgical testwork was conducted by ALS Metallurgy in
2019 results are present below:
Gold
· 48% recovery of gold by using gravity separation. The remaining
balance of non-gravity gold is recoverable in sulphide concentrates as a
by-product of standard flotation or via CIL scavenging.
Copper
· Quick floating copper minerals produced a high-grade copper
concentrate of approximately 30% Cu. Deleterious elements including arsenic
may be managed with a light concentrate polishing using regrind or blend
control. Recoveries depending on mineralogy, with 77-85% copper recoveries
achieved. Unrecovered copper minerals are represented by non-floating
silicates or secondary oxide copper minerals.
Cobalt
· Cobalt recoveries ranged from 73-79%. Potentially saleable cobalt
concentrate grades ranging between 2.3-5.3% Co were produced. Cobaltite
(CoAsS) is the dominant cobalt-bearing mineral and therefore intrinsically
linked to arsenic affecting its sale price. Given the potentially low-grade
nature of the Co concentrate, Artemis believe that the route to Co
monetization could include: (1) concentrate sale for blending into a
higher-grade feed thus ameliorating the low Co and high As content; (2)
potential route via oxidative hydrometallurgy involving concentrate roasting,
acid leaching and solvent extraction to form a Co salt; or (3) via some other
innovative leaching technique.
· Full and further testwork and evaluation is required to resolve the
monetization of Co at Greater Carlow.
Future Work
· It is recommended that additional metallurgical testwork be
undertaken to understand how individual comminution and metallurgical
responses may differ through the weathered zones for each proposed ore zone.
· Further metallurgical drilling at an approximate 50 m to 100 m
spacing along strike of the deposit within the optimised pit shell.
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.
· No assumptions regarding waste and process residue disposal have been
made.
· No assumptions of arsenic or sulphur have been made at this stage of
the project.
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.
· There was insufficient density data per domain to accurately estimate
density.
· Density was hard coded based on exploratory data analysis, comparison
to previous studies and empirical data density values.
· Bulk density data was derived from either downhole geophysical gamma
density or from core using water immersion on HQ3 core.
· Good correlation of density between gamma density and diamond density
determinations is recorded.
· Bulk density data was coded into the block model based on weathering
and mineralised domain. A summary of the values used is shown below:
Domain Weathering Bulk density assigned (t/m3)
Mineralised overburden Overburden 1.94
Mineralised oxide Oxide 2.51
Mineralised transitional Transitional 2.73
Mineralised fresh Fresh 2.88
Country rock overburden Overburden 1.94
Country rock oxide Oxide 2.43
Country rock trans Transitional 2.75
Country rock fresh Fresh 2.86
· 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.
· Gamma density is a quantitative, in-situ measurement of density that
accounts for void spaces. The measurements have been calibrated to regular
calibration holes in the iron ore deposits of the Pilbara, and on material at
the contractors' facilities.
· The water immersion method measurements were determined by measuring
the weight of part or the entire sample in air and water and then applying the
formula bulk density = weight (air)/ weight (air) - weight (water).
· Samples of drill core were sealed with masonry sealant/wax and
allowed to dry prior to bulk density determination.
· Discuss assumptions for bulk density estimates used in the evaluation
process of the different materials.
· The gamma density data were considered sufficient in number for all
material types, quantitative and unbiased.
· Calibration was undertaken using comparison to other holes and to
density measured by water immersion.
· Density values assigned are robust considering the stage of the
project and consummate resource classification.
Classification
· The basis for the classification of the Mineral Resources into
varying confidence categories.
· The Greater Carlow deposit is classified as an Inferred Mineral
Resource. The cut-off boundary for Inferred to unclassified has been
determined based on estimation quality parameters, drill spacing, estimation
search pass, extrapolation, and qualitative risk in the underlying geological
interpretation. The classification also takes into consideration the level of
geological knowledge of the deposit, density data coverage, soluble/insoluble
copper speciation and sampling/assaying protocols.
· 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).
· The classification reflects the overall confidence in the Greater
Carlow deposit based on observed continuity at the current drill spacing.
· Continuity is consistent at the current drill spacing and
orientation.
· Whether the result appropriately reflects the Competent Person's view
of the deposit.
· The Inferred Mineral Resource results are in line with expectations
of the Competent Persons.
· The Inferred Mineral Resource has been reported within an optimised
pit shell and the underground resource constrained to a Mining Stope Optimiser
(MSO) run, indicating reasonable prospects of eventual economic extraction.
· The Inferred Mineral Resource statement is in line with prior MRE
estimations, notably grade and contained ounces.
Audits or reviews
· The results of any audits or reviews of Mineral Resource estimates.
· The MRE has been peer reviewed as part of Snowden Optiro standard
internal peer review process by Mr. Ian Glacken FAusIMM(CP) FAIG MIMMM(CEng).
Covering, but not exclusive to geological interpretation of mineralised
domains, domain coding and compositing, top-cuts, estimation
method/suitability and input parameters to the resultant estimate.
· Snowden Optiro and Artemis have applied RPEEE factors to the
Reportable Resource via the use of a Whittle Shell and MSO.
· No reviews external to Snowden Optiro or Artemis have been undertaken
on this Mineral Resource estimate.
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 relative accuracy of the Greater Carlow Mineral Resource Estimate
is reflected in the reporting of the Mineral Resource as per the guidelines of
the 2012 JORC Code.
· The Mineral Resource was validated against the input composite data.
· The statement relates to a global estimate of tonnes and grade by
combining Reportable Resource within the optimised open pit cut-off utilising
a cut-off 0.7 g/t Au Eq. and MSO constrained underground resource reported at
a cut-off 2 g/t Au Eq.
· 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.
· Confidence in the Mineral Resource estimate is consummate to guidance
in the JORC Code 2012.
· The Mineral Resource statement relates to a global estimate of
in-situ tonnes and grade.
· These statements of relative accuracy and confidence of the estimate
should be compared with production data, where available.
· No production data is available for comparison.
1 Gold equivalent equations for the oxide, transition and fresh domains are
given below:
Oxide Au Eq. = Au(g/t) + Cu(%) x 0.86 + Co(%) x 2.31
Transitional Au Eq. = Au(g/t) + Cu(%) x 0.81 + Co(%) x 2.17
Fresh Au Eq. = Au(g/t) + Cu(%) x 1.31 + Co(%) x 3.96
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