TIDMCOBR
RNS Number : 6341L
Cobra Resources PLC
07 September 2023
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7 September 2023
Cobra Resources plc
("Cobra" or the "Company")
Rare Earth and Gold Resource Upgrades
Unique and Economically Advantageous Dual Resource Project
Cobra, a gold, rare earth and IOCG exploration company focused
on the Wudinna Project in South Australia, is pleased to announce
upgrades to both its Rare Earth Elements ("REE") and Gold JORC
Mineral Resource estimates ("MRE"), which establish this dual
resource project as unique and economically advantageous.
Highlights - Rare Earth Elements
-- Upgraded REE MRE includes:
o +99% increase in tonnes
o +5% increase in Magnet Rare Earth Oxide ("MREO") grade
o +109% increase in MREO metal content
-- An exclusively unique REE resource that overlies the Baggy
Green and now, Clarke gold resources, providing a competitive
metric for low operational costs
Highlights - Gold
-- Upgraded Gold MRE includes:
o +32% increase in gold metal (+68,000 Oz)
o +1.4Mt increase in ore tonnes
o 33,000 Oz maiden MRE estimate at the Clarke prospect
-- Shallow resource - all resource ounces occur within 200m of
surface, presenting as low cost, camp scale open pit extraction
with enhanced economics from REE overburden
-- Total gold resource of 5.8Mt at 1.5 g/t gold for 279,000 Oz
-- Gold ounce increases across all deposits, demonstrating
potential for additional growth through infill and further
extensional drilling
Rupert Verco, CEO of Cobra, commented:
"It is pleasing to see resource extension at all gold deposits
and a doubling of rare earth resources, achieved at exceptionally
low cost.
We are one step closer to demonstrating the commercial value of
this unique dual resource and Wudinna is undoubtedly presenting as
an economically advantageous project to take forward.
Cobra's rare earth strategy has been based upon economic
viability. Defining rare earths within overburden provides a
competitive edge when compared to stand-alone clay-hosted REE
projects - with the exciting additional potential of ionic
mineralisation at Boland, where we are eagerly awaiting final
metallurgical results to validate proof-of-concept for in
situ-leachable, low cost and sustainable sourcing of critical
minerals.
Between our growing resources and our pipeline of targets such
as Boland, Cobra is delivering transformational exploration success
with potentially global implications."
The 2023 Gold and REE JORC MRE updates are defined below:
Table 1: Wudinna Project 2023 JORC MRE Update
Gold Mineral Resource Rare Earth Mineral Resource Estimate
Estimate
===========================
Category Deposit Tonnes Au Ounces Tonnes TREO MREO LREO HREO Pr(6) Nd(2) Dy(2) Tb(4)
O(11) O(3) O(3) O(7)
========= ======= ==== ============ ===== ===== ===== ===== ====== ====== ====== =========
Mt g/t oz Mt ppm ppm ppm ppm ppm ppm ppm ppm
Indicated Barns 0.44 1.3 18,000 - - - - - - - - -
---------
Inferred 2.19 1.6 116,000 - - - - - - - - -
---------------------- ------- ---- ------------ ------- ----- ----- ----- ----- ------ ------ ------ ---------
Baggy
Inferred Green 2.12 1.4 96,000 15.1 652 142 512 140 29 97 14 2
Inferred Clarke 0.73 1.4 33,000 26.5 725 175 571 154 35 122 16 3
White
Inferred Tank 0.33 1.5 16,000 - - - - - - - - -
----------- --------- ------- ---- ------------ ------- ----- ----- ----- ----- ------ ------ ------ ---------
Total 5.81 1.5 279,000 41.6 699 163 549 149 33 113 15 3
======= ==== ============ ======= ===== ===== ===== ===== ====== ====== ====== =========
Rare Earth Mineral Resources reported above a cut-off grade of
320 ppm TREO-Ce
Gold Mineral Resource reported above a cut-off grade of 0.5 g/t
gold
The Wudinna Project's gold resource comprises four primary,
shallow, camp scale gold occurrences. The alteration mineralogy and
structural genesis associated with the gold mineralisation event is
believed to act as a catalyst for REE enrichment and mobilisation.
The spatial proximity of rare earth mineralisation has the
potential to economically complement the gold mineralisation.
The Wudinna Project's unique REE resource lends itself to a
sustainable supply of critical minerals central to decarbonisation,
owing to the resource's position as overburden. Metallurgical
testwork has demonstrated MREO recoveries of up to 35% at a pH 1.
In comparison to other clay-hosted REE projects, these results are
considered economically competitive. Further testwork is underway
to enhance recoveries without materially increasing acidities which
impact cost and environmental risk. Current studies include
beneficiation, material characterisation and gangue element
management. This work is iterative in nature.
Figure 1: Locality plan - Wudinna Project 2023 MRE Update
Figure 2: Cross section of the Clarke and Baggy Green dual gold
and REE resource models demonstrating the complementary spatial
nature of the MREs
Figure 3 : Wudinna Project gold MRE variance since the 2019
MRE
Figure 4 : Grade tonnage curve for the Baggy Green and Clarke
rare earth MRE demonstrates the relative relationship between grade
and tonnage distribution. The cut-off grade of 320 ppm TREO-Ce
reflects the deflection point between background and grade
enrichment
Enquiries:
Cobra Resources plc via Vigo Consulting
Rupert Verco (Australia) +44 (0)20 7390 0234
Dan Maling (UK)
SI Capital Limited (Joint Broker)
Nick Emerson
Sam Lomanto +44 (0)1483 413 500
Shard Capital Limited (Joint Broker)
Erik Woolgar
Damon Heath +44 (0)20 7186 9952
Vigo Consulting (Financial Public
Relations)
Ben Simons
Kendall Hill +44 (0)20 7390 0234
The person who arranged for the release of this announcement was
Rupert Verco, Managing Director of the Company .
About Cobra
Cobra is defining a unique multi-mineral resource at the Wudinna
Project in South Australia's Gawler Craton, a tier one mining and
exploration jurisdiction which hosts several world-class mines.
Cobra's Wudinna tenements total 1,832 km(2) , with other nearby
tenement rights totalling 1,429 km(2) .
Cobra's Wudinna tenements also contain extensive orogenic gold
mineralisation and are characterised by potentially open-pitable,
high-grade gold intersections, with ready access to infrastructure.
Cobra has 22 orogenic gold targets outside of the current 279,000
Oz gold JORC Mineral Resource Estimate.
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Competent Persons Statement
The information in this announcement that relates to the
estimation and reporting of the gold Mineral Resource estimates for
the Barns, Baggy Green and White Tank Deposits and the Clarke and
Baggy Green REE Mineral Resource estimates has been compiled by Mrs
Christine Standing BSc Hons (Geology), MSc (Min Econs), MAusIMM,
MAIG. Mrs Standing is a Member of the Australian Institute of
Geoscientists and the Australian Institute of Mining and Metallurgy
and is a full-time employee of Snowden Optiro (Optiro Pty Ltd) and
has acted as an independent consultant. The information in this
announcement that relates to the estimation and reporting of the
gold Mineral Resource estimate for Clarke has been compiled by Ms
Justine Tracey BSc Hons (Geology), MSc (Geostatistics), MAusIMM. Ms
Tracey is a Member of the Australian Institute of Geoscientists and
is a full-time employee of Snowden Optiro (Optiro Pty Ltd) and has
acted as an independent consultant.
Mrs Christine Standing and Ms Justine Tracey have sufficient
experience with the style of mineralisation, deposit type under
consideration and to the activities undertaken to qualify as
Competent Persons as defined in the 2012 Edition of the
"Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves (The JORC Code). Mrs Standing and Ms
Tracey consent to the inclusion in this announcement of the
contained technical information relating the Mineral Resource
estimations in the form and context in which it appears.
Information in this announcement has been assessed by Mr Rupert
Verco, a Fellow of the Australasian Institute of Mining and
Metallurgy ("FAusIMM"). Mr Verco an employee of Cobra has more than
16 years' industry experience which is relevant to the style of
mineralisation, deposit type 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 Exploration Results,
Mineral Resources and Ore Reserves (the "JORC" Code). This includes
11 years of mining, Mineral Resource estimation and
exploration.
Information in this announcement relates to exploration results
that have been reported in the following announcements:
-- "Wudinna Gold Resource Update", dated 7 May 2019
-- "Wudinna Project Update - Initial Gold and Rare Earth Results", dated 14 December 2021
-- "Wudinna Project Update - Northern Drillholes at Clarke
Intersect Additional Gold Mineralisation, Additional Rare Earth
Intersections Directly Above Gold Zones", dated 7 February 2022
-- "Wudinna Project Update - Re-Analysis Defines Large Rare
Earth Mineralisation Footprint Above Baggy Green and Clarke Gold
Mineralisation", dated 4 May 2022
-- "Wudinna Project Update - Aircore Drilling Yields Exceptional
Gold and Rare Earth Results at Clarke" dated 16 August 2022
-- "Wudinna Project Update - Maiden Rare Earth Resource Estimate
- Unique and Unconstrained", dated 9 January 2023
-- "Wudinna Project Update - Initial RC Drilling Results
Underpin Gold Resource Growth Potential - Completion of Aircore
Drilling Confirms Highly Prospective Conditions for Ion-Adsorbed
Rare Earths", dated 9 May 2023
-- "Drilling Defined REE Resource Extension potential", dated 12 June 2023
Definitions
REE - Rare Earth Elements
REO - Rare Earth Oxides
MREO - Magnet Rare Earth Oxides (dysprosium + terbium +
praseodymium, neodymium)
TREO - Total Rare Earth Oxides plus yttrium
TREO-Ce - Total Rare Earth Oxides plus yttrium and minus
cerium
Further Information Regarding the REE and Gold MREs
Location and Land Tenure
The Wudinna Project is located on the northern Eyre Peninsula,
within South Australia, a tier 1 mining jurisdiction. The defined
REE MRE occurs within EL 6131 (Corrobinnie) and lies within the
Pinkawillinie Conservation Park (dual proclamation land). The
tenement is held by Peninsula Resources, a subsidiary of Andromeda
Metals. Cobra is entitled to 75% ownership in the project through
the Wudinna Heads of Agreement. In April 2023, the Company
announced it had achieved its 75% earn-in obligation.
Figure 5 : Locality plan
Geology and Nature of Gold and REE Mineralisation
The gold and REE deposits at the Wudinna Project are considered
to be related to the structurally controlled basement weathering of
epidote-pyrite alteration related to the 1,590 Ma Hiltaba/GRV
tectonothermal event of the Gawler Craton. Gold and REE
mineralisation has a spatial association with mafic
intrusions/granodiorite alteration and is associated with
metasomatic alteration of host rocks. Epidote alteration associated
with gold mineralisation is REE enriched and believed to be the
primary source.
Gold mineralisation at Barns is associated with a large
hydrothermal alteration halo. Within the host granodiorite the
outermost alteration comprises a propylitic alteration zone where
primary biotite is altered to chlorite, the composition of primary
plagioclase becomes albite, and iron sourced from accessory
magnetite and possibly biotite is oxidised and forms a red dusting.
Epidote is common and may form from the calcium lost from the
plagioclase during albitisation. The propylitic altered rocks
display fine scale micro-fracturing which has allowed ingress of
hydrothermal fluids. At Baggy Green, the host rocks are visibly
altered and sheared in and around the mineralised zone. Alteration
phases include biotite, chlorite, sericite and possibly
hydrothermal magnetite. Gold occurs as free grains which can be
panned from drill samples. The gold mineralisation style at Barns
is reflective of the general features of the gold resources at
Baggy Green, Clarke and White Tank.
The REE mineralisation is regionally extensive in weathered
(saprolite and saprock) zones developed on basement rocks. The
nature of controlling structures that act as conduits for gold
mineralisation are also thought to act as catalysts for the
secondary processes that promote weathering and subsequent
mobilisation of REEs to the saprolite and saprock. Weathering
processes have resulted in a supergene enrichment of gold withing
the saprolite and saprock horizons.
The following simplified model is proposed for ionic REEs at the
Clarke and Baggy Green prospects:
-- Gold and sulphide mineralisation is directly associated with
Hiltaba Suite volcanics (1,590-1,575 Ma)
-- WNW Riedel shears, under north-south compression (craton
emplacement) act as dilatational conduits through Kimban and
Sleaford age granitoids
-- Hiltaba suite mafics are enriched in light REEs
-- Gold and sulphide mineralisation forms along sheeted
granitoid "dome" joints, bound within shear zones
-- Sericite and epidote alteration halos form peripheral to gold mineralisation
-- Epidote alteration is enriched in REEs providing an enriched rare earth source
-- Supergene enrichment of gold occurs at the base of oxidation
where the weathering of primary sulphides generates acidic
conditions
-- Primary REE phases are weathered to secondary REE phases through prolonged weathering
-- Acidic conditions generated by the weathering of sulphides re-mobilises REEs
-- Near redox boundaries (pH 6-7) a greater component of REE are adsorbed to clay particles
-- Colloidal phases occur as conditions become alkaline
Figure 6 : Proposed geological model for gold and REE
mineralisation at the Clarke and Baggy Green prospects
X-Ray Diffraction analysis performed by the Commonwealth
Scientific and Industrial Research Organisation supports that a
component of REE bursary is adsorbed to the primary clay particles,
being kaolin and montmorillonite, in similar fashion to the highly
desirable Ion Adsorbed Clay ("IAC") hosted deposits of southern
China.
SEM analyses performed by the University of South Australia
determined that:
-- Primary REE mineral phases in basement, hard rock lithologies
are zircon, titanite, apatite, andradite, epidote
-- Secondary REE mineral phases within the lower saprock (weakly
to moderately weathered basement) are monazite, bastnaesite,
allanite, rutile
Figures 7-9 : SEM imagery of samples from 27, 47 and 117m
downhole of CBRC0042
-- REE enrichment in source rock is associated with Hiltaba
intrusive alteration, the primary gold mineralising event
-- Elevated phosphate is identified at the base of saprolite,
however the peak is not associated with elevated REE grades (Figure
10)
Figure 10 : REE grades downhole of CBRC0042 intersected 8.2m at
561 ppm TREO from 38.1m below surface, and 19m at 0.79 g/t gold
from 83m, including 5m at 2.62 g/t gold from 95m
-- Definitive change in REE bearing mineral phases between
basement and saprolite, demonstrated by the calculated mass
abundance of respective REE mineral phases
-- Rare earth grade peaks in the upper saprolite occur where
secondary REE phases are low, supporting clay adsorption
The identified changes in mineral phase from hard rock to lower
saprock and the occurrence of grade peaks within the weathered
saprolite with very low identifiable rare earth mineral phases is
supportive of a component of the REE bursary being adsorbed to clay
particles and is analogous to the ionic rare earth deposits of
Southern China.
Figure 11 : CBRC0042 downhole REO grades, sample pH and the SEM
calculated primary and secondary rare earth bearing mineral
phases
Drilling data and intersections can be located in company
announcement: "Wudinna Project Update - Northern Drillholes at
Clarke Intercept Additional Gold Mineralisation - Additional Rare
Earth Interceptions Directly Above Gold Zones", dated 07 February
2022
Drilling Techniques
The Barns Mineral Resource estimate is based on 94 drillholes
(11,193.1m) consisting of Diamond ("DD"), Reverse Circulation
("RC"), and Rotary Hammer ("RH"). 20 holes have been drilled by
Cobra since 2019.
The White Tank Resource is based on 49 drillholes (3,687m)
consisting of RC and RH drilling. 5 holes have been drilled by
Cobra since 2019.
The Baggy Green Resource is based on 102 holes (9,433.0m)
consisting of DD, RC, and RH drilling. 15 holes have been drilled
by Cobra since 2019.
The Clarke Resource is based on 87 holes (7,789m) consisting of
AC and RC drilling. 67 holes have been drilled by Cobra since
2019.
The Rare Earth Mineral Resource estimate is based upon the drill
results or re-analysis of 271 drillholes (19,065.1m) that consist
of Aircore ("AC"), RH, and RC and a single DD drillhole. 48 RC and
69 AC holes have been drilled by Cobra since 2019. All rare earth
results incorporated within the MRE were announced during 2022 and
2023.
The drillhole spacing within the Mineral Resource for the rare
earths area is generally 200m by 200m, however areas of tighter
drilling and sampling occur proximal to gold mineralisation where
drill density is up to 25m by 100m. The drillhole spacing for the
gold resources is on transects designed at 50-80m apart. Drillholes
are typically 50-60m apart on the drill lines in the Inferred
Mineral Resource areas. At Barns the drillhole spacing narrows to
50m by 20m in the area where Mineral Resources have been classified
as Indicated.
Sampling and Sub-sampling Techniques
Downhole sample composites vary over the Mineral Resources, with
historic drilling and subsequent re-analysis being performed on
pulp samples from 1m, 2m, 4m and 6m down-hole intervals. Samples
from Cobra's drilling have produced 1m composites from RC drilling
and 2-3m from AC drilling. Owing to the variable nature of REE
mineralisation through the saprolite, greater composite lengths are
expected to understate grade.
RC drill samples were collected via a rig mounted cyclone and
cone splitter to produce 2-4kg of sample. A riffle splitter was
used to split any oversize samples to the 2-4kg size.
AC samples were collected via a rig mounted cyclone into a green
bag or bucket for each 2-3m interval. A PVC spear was used to
collected a representative 2-4kg.
Samples were collected from the top of hole. Samples for REE
analysis were submitted from the top of the saprolite profile to
the end of hole.
Sample Analysis Methods
From 2019 to the end of 2022, samples were submitted to
Genalysis Intertek Laboratories, Adelaide, for preparation and
analysis. Multi-element geochemistry was digested by four acid
ICP-MS and analysed for Ag, Ce, Cu, Dy, Er, Eu, Gd, Ho, La, Lu, Na,
Nd, Pr, Sc, Sm, Tb, Th, Tm, U, Y and Yb. Au analysis was completed
through 50g and 25g fire assay.
From the start of 2023, samples were submitted to Bureau
Veritas, Adelaide for preparation and analysis. Multi-element
geochemistry was digested by four acid ICP-MS/ ICP-OES and analysed
for Ag, Ce, Cu, Dy, Er, Eu, Gd, Ho, La, Lu, Mg, Na, Nd, P, Pr, Sc,
Sm, Tb, Th, Tm, U, Y and Yb. Au analysis was completed through 50g
fire assay.
Mineral Resource Estimation and Classification
The REE and gold Mineral Resources have been estimated by
independent consultants to the Company, Snowden Optiro.
The resource model for the REE mineralisation at Clarke and
Baggy Green was constructed using a parent block size of 25 mE by
40 mN on 1 m benches and the parent blocks were allowed to sub-cell
down to 5 mE by 10 mN by 0.5 mRL to more accurately represent the
geometry and volume of the saprolite and saprock domains.
Categorical Indicator Kriging ("CIK") at the sub-cell resolution
was used to define REE mineralised (>100 ppm CeO(2) at a 45%
threshold) blocks. The REE block grades were estimated using
ordinary kriging. All REE (La(2) O(3) , CeO(2) , Pr(6) O(11) ,
Nd(2) O(3) , Sm(2) O(3) , Eu(2) O(3) , Gd(2) O(3) , Tb(4) O(7) ,
Dy(2) O(3) , Ho(2) O(3) , Er(2) O(3) , Tm(2) O(3) , Yb(2) O(3) ,
Lu(2) O(3) and Y(2) O(3) ) were estimated independently.
The gold resource model at Barns was constructed on a block size
of 10 mE by 10 mN on 4m benches. At White Tank, a parent block size
of 10 mE by 20 mN on 4m benches was used. At Clarke, 25mE by 25 mN
on a 3m bench blocks were used and at Baggy Green a parent block
size of 10 mE by 10 mN on 5m benches were used.
The REE Mineral Resources and the majority (96%) of the gold
Mineral Resources have been classified as 'Inferred' on the basis
of confidence in geological and grade continuity and taking into
account data quality, data density and confidence in the grade
estimation, using the modelled grade continuity. In places, the
drillhole density is sufficient to support a higher Mineral
Resource classification and scope exists to review the current
Mineral Resource classification if positive results are obtained
from additional metallurgical studies that support economic
viability.
An area of Barns has been classified as Indicated within areas
where drill spacing is generally 20 mE by 50 mN or less and is
above 20 mRL.
At Clarke, two northern mineralisation domains have not been
included in the Mineral Resource estimate due to limited confidence
in geometry and grade distribution. These areas have been
classified as exploration potential.
Density
Weathering domains that reflect the controls to rare earth
distribution were produced to remove transported cover and fresh
basement from the REE Mineral Resource estimate. Within the
saprolite domain, density was measured for 19 saprolite samples
from diamond drilling at the Baggy Green and Barns gold prospects
that exhibit a range of densities between 1.2 t/m(3) and 2.01
t/m(3) . The average density of 1.6 t/m(3) was applied for tonnage
estimation of the REE Mineral Resource.
No changes have been applied to the bulk density parameters used
for the gold Mineral Resource estimates. As previously reported, a
total of 255 bulk density determinations were undertaken at Barns
on either historical or recent DD drillholes and 185 bulk density
determinations were undertaken at Baggy Green on recent DD
drillholes. Average values were calculated from the complete
dataset by Mining Plus in 2016 and were used in the "Wudinna Gold
Resource Update", dated 7 May 2019. The average values determined
for the transitional material and the fresh mineralisation at Barns
were applied to the Barns and White Tank (located 1 km to the south
of Barns) Mineral Resource estimates and the average values
determined for the supergene and fresh mineralisation at Baggy
Green were applied to the Clarke and Baggy Green Mineral Resource
estimates.
Cut-off Grade
The REE Mineral Resource has been reported above a cut-off grade
of TREO-Ce of 320 ppm and assumes extraction by open pit mining.
The cut-off grade was selected based on the evaluation of other
advanced clay-hosted rare earth mineral resources and the
consideration that future economic analysis of the cut-off grade is
likely to incorporate parameters that support extraction of the
underlying gold mineralisation.
A gold cut-off grade of 0.5 g/t has been selected to reflect
current commodity prices and a likely open pit mining option in
conjunction with the overlying rare earth extraction.
Metallurgy
-- Preliminary metallurgical test work focusing on extraction techniques adopted to ionic phase mineralisation using H(2) SO(4) as a lixiviant, and performed by Australia's Nuclear Science and Technology Organisation, yielded recoveries of up to 34% Total Rare Earth Element ("TREE") from samples across two holes at Clarke
-- Preliminary metallurgical testwork has provided positive
indications that REE bursary is bound to clay particles. The
identification of a technique or techniques to optimally recover
rare earth metals from the saprolite mineralisation is ongoing with
further desorption and leach testing underway
-- pH testing of drill samples demonstrates variable conditions
across all prospects, saprolite horizons, and types of clays that
are associated with high REE adsorption capacity
-- The nature of the bonds which adsorb the REEs within
enclosing clay appear dependent upon the local chemical
environment:
o Where local pH is greater than optimal (moderately alkaline),
colloidal bonding is more abundant and a positive cerium anomaly is
generally present
o Where local pH is in an optimal range, ionic bonding appears
favoured, the valuable MREO mineral suite is enhanced (pH 5-6.8),
and REE baskets generate negative cerium anomalies
o Where local pH is lower than optimal (acidic), REEs appear to
have remained mobile and enhanced grades are not retained within
the saprolite zone
-- pH testwork completed to date provides an encouragement that
it can be utilised as a process to identify metallurgical
upside
-- REE grade is considerably higher at pH conditions 6-7 and
9-10. Should further metallurgical testing support a higher
component of ionic adsorption, then saprolite acidity will be a key
identifier for determining higher grades and zones amenable to
lower processing costs
Figure 12 : TREO breakdown of the Clarke dataset evaluating
drillhole grades at a cut-off of 350 ppm TREO compared to a pH
range of 6-7
The likelihood of eventual economic extraction of gold was
considered in terms of possible open pit mining and results from
metallurgical testwork commissioned by Andromeda in 2017.
Metallurgical testwork from material at Barns and Baggy Green
indicated gold recoveries ranging from 94.3% to 99.3% and averaging
97.7% across all samples from a combination of conventional gravity
and cyanide leaching.
Gold and REE Mineral Resource update
Appendix 1: JORC Code, 2012 Edition - Table 1
The table below summaries the assessment and reporting criteria
used for the Barns, White Tank, Clarke and Baggy Green gold Mineral
Resource estimates and the Clarke and Baggy Green REE Mineral
Resource estimates and reflects the guidelines in Table 1 of The
Australasian Code for the Reporting of Exploration Results, Mineral
Resources and Ore Reserves (the JORC Code, 2012).
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling Pre 2021
techniques * Nature and quality of sampling (eg cut channels,
random chips, or specific specialised industry * Historic RC and RAB drilling methods have been
standard measurement tools appropriate to the employed at the Barns, White Tank, Clarke and Baggy
minerals under investigation, such as down hole gamma Green prospects.. diamond (DD) drillholes have been
sondes, or handheld XRF instruments, etc). These incorporated in the Barns and Baggy Gren Mineral
examples should not be taken as limiting the broad Resource estimates.
meaning of sampling.
* Include reference to measures taken to ensure sample * Pulp samples from pre-Cobra Resources' drilling were
representivity and the appropriate calibration of any collected with intervals of 1-6 m. Samples were
measurement tools or systems used. riffle split if dry or sub split using a trowel if
wet.
* Aspects of the determination of mineralisation that
are Material to the Public Report.
* Pulp samples were obtained from Challenger geological
services using a combination of logging and
* In cases where 'industry standard' work has been done geochemical selection criteria. Samples pulled from
this would be relatively simple (eg 'reverse storage were re-pulverised at the laboratory prior to
circulation drilling was used to obtain 1 m samples further analysis.
from which 3 kg was pulverised to produce a 30 g
charge for fire assay'). In other cases more
explanation may be required, such as where there is
coarse gold that has inherent sampling problems. 2021 - 2022
Unusual commodities or mineralisation types (eg
submarine nodules) may warrant disclosure of detailed * Sampling during Cobra Resources 2022 aircore ("AC")
information. drilling programme at all prospects were obtained
through AC drilling methods.
* 2 m samples were collected in 20l buckets via a rig
mounted cyclone. An aluminum scoop was used to
collect a 2-4 kg sub sample from each bucket. Samples
were taken from the point of collar, but only samples
from the commencement of saprolite were selected for
analysis.
* Samples submitted to the Genalysis Intertek
Laboratories, Adelaide and pulverised to produce the
25g fire assay charge and 4 acid digest sample.
* A summary of previous RC drilling at the Wudinna
Project is outlined in the Cobra Resources' RNS
number 7923A from 7 February 2022.
2023
RC
* Samples were collected via a Metzke cone splitter
mounted to the cyclone. 1m samples were managed
through chute and butterfly valve to produce 2-4 kg
of sample from the collar. Samples from the
commencement of saprolite were selected for analysis.
* Samples were submitted to Bureau Veritas Laboratories,
Adelaide and pulverized to provide 50g fire assay
charge and 4 acid digest sample.
AC
* A combination of 2m and 3m samples were collected in
green bags via a rig mounted cyclone. A PVC spear was
used to collect a 2-4kg sub sample from each green
bag. Sampling commenced from the collar point with
samples submitted for analysis from the top of
saprolite.
* Samples were submitted to Bureau Veritas Laboratories,
Adelaide and pulverized to prude 50g fire assay
charge and 4 acid digest sample.
============================================================ =======================================================================
Drilling Pre 2021
techniques * Drill type (eg core, reverse circulation, open-hole * Drill methods include AC, RH and RAB in
hammer, rotary air blast, auger, Bangka, sonic, etc) unconsolidated regolith and aircore hammer in hard
and details (eg core diameter, triple or standard rock. Some shallow RC holes have been drilled in
tube, depth of diamond tails, face-sampling bit or place of AC and RAB, a single diamond drillhole has
other type, whether core is oriented and if so, by been incorporated in the Barns Mineral Resource
what method, etc). estimate.
2021- 2022
* Drilling completed by McLeod Drilling Pty Ltd using
75.7mm NQ air core drilling techniques from an ALMET
aircore rig mounted on a Toyota Landcruiser 6x6 and a
200psi, 400cfm Sullair compressor.
* Slimline RC drilling was completed by Wasdrill Pty
Ltd and Indicator drilling services Pty Ltd using a
400D and Mantis C60R drill rigs using a 4" hammer and
78mm drill rods.
2023
* Drilling completed by Bullion Drilling Pty Ltd using
5 3/4 " reverse circulation drilling techniques from
a Schramm T685WS rig with an auxiliary compressor.
* Drilling completed by McLeod Drilling Pty Ltd using
75.7 mm NQ air core drilling techniques from an ALMET
Aircore rig mounted on a Toyota Landcruiser 6x6 and a
200psi, 400cfm Sullair compressor.
============================================================ =======================================================================
Drill sample
recovery * Method of recording and assessing core and chip * Sample recovery was generally good. All samples were
sample recoveries and results assessed. recorded for sample type, quality and contamination
potential and entered within a sample log.
* Measures taken to maximise sample recovery and ensure
representative nature of the samples.
* In general, AC sample recoveries were good with 10 kg
for each 1 m interval being recovered from AC
* Whether a relationship exists between sample recovery drilling.
and grade and whether sample bias may have occurred
due to preferential loss/gain of fine/coarse
material.
* In general, RC sample recoveries were good with 35-50
kg for each 1 m interval being recovered.
* No relationships between sample recovery and grade
have been identified.
============================================================ =======================================================================
Logging
* Whether core and chip samples have been geologically * All drill samples were logged by an experienced
and geotechnically logged to a level of detail to geologist at the time of drilling. Lithology, colour,
support appropriate Mineral Resource estimation, weathering and moisture were documented.
mining studies and metallurgical studies.
* Whether logging is qualitative or quantitative in * Logging is generally qualitative in nature.
nature. Core (or costean, channel, etc) photography.
* The total length and percentage of the relevant * All drill metres have been geologically logged on
intersections logged. sample intervals (1-3 m).
============================================================ =======================================================================
Sub-sampling Pre-2021
techniques * If core, whether cut or sawn and whether quarter,
and sample half or all core taken. * Diamond drilling was used to confirm composite sample
preparation selection. Core was halved and sampled according to
geology rather than down hole composite length.
* If non-core, whether riffled, tube sampled, rotary
split, etc and whether sampled wet or dry.
* Samples from AC, RAB and "bedrock" RC holes have been
* For all sample types, the nature, quality and collected initially as 6 m composites followed by 1 m
appropriateness of the sample preparation technique. re-splits. Many of the 1 m re-splits have been
collected by riffle splitting.
* Quality control procedures adopted for all
sub-sampling stages to maximise representivity of
samples. * RC samples have been collected by riffle splitting if
dry, or by trowel if wet.
* Measures taken to ensure that the sampling is
representative of the in situ material collected,
including for instance results for field * Pulverised samples have been routinely checked for
duplicate/second-half sampling. size after pulverising.
* Whether sample sizes are appropriate to the grain
size of the material being sampled. * Pulp samples were re- pulverized after storage to
re-homogenise samples prior to assay.
2021-2022
* The use of an aluminum scoop to collect the required
2-4kg of sub-sample from each 2m AC sample length
controlled the sample volume submitted to the
laboratory.
* Additional sub-sampling was performed through the
preparation and processing of samples according to
the Intertek Genalysis internal protocols.
* Duplicate AC samples were collected from the sample
buckets using an aluminum scoop at a 1 in 50 sample
frequency.
* Sample sizes were appropriate for the material being
sampled.
* Assessment of duplicate results indicated this sub -
sample method provided appropriate repeatability for
rare earths and gold.
* RC samples were sub sampled using a cyclone rig
mounted splitter with recoveries monitored using a
field spring scale.
* Manual re-splitting of RC samples through a riffle
splitter was undertaken where sample sizes exceeded
4kg.
* RC field duplicate samples were taken nominally every
1 in 20 samples. These samples showed appropriate
repeatability for rare earth elements and gold.
2023
* The use of a PVC spear to collect the required 2-4kg
of sub-sample from each 2-3m AC sample length
controlled the sample volume submitted to the lab.
* Additional sub-sampling was performed through the
preparation and processing of samples according to
the Bureau Veritas internal protocols.
* Duplicate AC samples were collected from the sample
buckets using an PVC spear scoop at a 1 in 25 sample
frequency.
* Sample sizes were appropriate for the material being
sampled.
* Assessment of duplicate results indicated this sub -
sample method provided appropriate repeatability for
rare earths and gold.
* RC samples were sub sampled using a cyclone rig
mounted splitter with recoveries monitored using a
field spring scale.
* Manual re-splitting of RC samples through a riffle
splitter was undertaken where sample sizes exceeded
4kg.
* RC field duplicate samples were taken nominally every
1 in 25 samples. These samples showed appropriate
repeatability for rare earth elements and gold.
============================================================ =======================================================================
Quality of
assay data * The nature, quality and appropriateness of the * Samples were submitted to Genalysis Intertek
and assaying and laboratory procedures used and whether Laboratories, Adelaide for preparation and analysis
laboratory the technique is considered partial or total. to the end of 2022. Multi element geochemistry were
tests digested by four acid ICP-MS and analysed for Ag, Ce,
Cu, Dy, Er, Eu, Gd, Ho, La, Lu, Na, Nd, Pr, Sc, Sm,
* For geophysical tools, spectrometers, handheld XRF Tb, Th, Tm, U, Y and Yb.
instruments, etc, the parameters used in determining
the analysis including instrument make and model,
reading times, calibrations factors applied and their
derivation, etc. * From 2023 samples were submitted to Bureau Veritas,
Adelaide for preparation and analysis. Multi-element
geochemistry were digested by four acid ICP-MS/
* Nature of quality control procedures adopted (eg ICP-OES and analysed for Ag, Ce, Cu, Dy, Er, Eu, Gd,
standards, blanks, duplicates, external laboratory Ho, La, Lu, Mg, Na, Nd, P, Pr, Sc, Sm, Tb, Th, Tm, U,
checks) and whether acceptable levels of accuracy (ie Y and Yb.
lack of bias) and precision have been established.
* Field gold blanks, and multi element gold - rare
earth standards were submitted at a frequency of 1 in
25 samples.
* Field duplicate samples were submitted at a frequency
of 1 in 25 samples.
* Reported assays are to acceptable levels of accuracy
and precision.
* Internal lab blanks, standards and repeats for rare
earths indicated acceptable assay accuracy.
============================================================ =======================================================================
Verification
of sampling * The verification of significant intersections by * Sampling data was recorded in field books, checked
and assaying either independent or alternative company personnel. upon digitising and transferred to database.
* The use of twinned holes.
* Geological logging was undertaken digitally via the
MX Deposit logging interface and synchronised to the
* Documentation of primary data, data entry procedures, database at least daily during the drill programme.
data verification, data storage (physical and
electronic) protocols.
* Compositing of assays was undertaken and reviewed by
* Discuss any adjustment to assay data. Cobra Resources staff.
* Original copies of laboratory assay data are retained
digitally on the Cobra Resources server for future
reference.
* Samples have been spatially verified through Datamine
and Leapfrog geological software for pre 2021 and
post 2021 samples and assays.
* Twinned drillholes from pre 2021 and post 2021 drill
programmes showed acceptable spatial and grade
repeatability.
* Physical copies of field sampling books are retained
by Cobra Resources for future reference.
* Significant intercepts have been prepared by Mr
Rupert Verco and reviewed by Mr Robert Blythman.
============================================================ =======================================================================
Location of Pre 2021
data points * Accuracy and quality of surveys used to locate drill
holes (collar and down-hole surveys), trenches, mine * Collar locations were pegged using DGPS to an
workings and other locations used in Mineral Resource accuracy of +/-0.5 m.
estimation.
* Specification of the grid system used. * Downhole surveys have been completed for deeper RC
and diamond drillholes.
* Quality and adequacy of topographic control.
* Collars have been picked up in a variety of
coordinate systems but have all been converted to MGA
94 Zone 53. Collars have been spatially verified in
the field.
* Collar elevations were historically projected to a
geophysical survey DTM. This survey has been adjusted
to AHD using a Leica CS20 GNSS base and rover survey
with a 0.05 cm accuracy. Collar points have been
re-projected to the AHD adjusted topographical
surface.
2021- Onward
* Collar locations were initially surveyed using A
mobile phone GPS utilising the Avenza Map app. Collar
points recorded with a horizontal accuracy within 5m.
* Collar locations were picked up using a Leica CS20
base and Rover with an instrument precision of
0.05cm.
* Locations are recorded in geodetic datum GDA 94 zone
53.
* No downhole surveying was undertaken on AC holes. All
holes were set up vertically and are assumed
vertical.
* RC holes have been down hole surveyed using a Reflex
TN-14 true north seeking downhole survey tool or a
Reflex Multishot magnetic downhole survey tool.
* All surveys are corrected to MGA 94 Zone 53 northing
within the MX Deposit database.
.
============================================================ =======================================================================
Data spacing REE MRE data
and * Data spacing for reporting of Exploration Results. * Drillhole spacing was designed on transects 50 to 80m
distribution apart. Drillholes generally 50 - 60m apart on these
transects but up to 70m apart.
* Whether the data spacing and distribution is
sufficient to establish the degree of geological and
grade continuity appropriate for the Mineral Resource
and Ore Reserve estimation procedure(s) and * Additional scouting holes were drilled
classifications applied. opportunistically on existing tracks at spacings
25-150m from previous drillholes.
* Whether sample compositing has been applied.
Gold MRE data
* Drill lines at Barns have been drilled mainly on a 50
m section spacing with some sections having been
drilled 25 m apart. Drillhole spacings on section
vary but on average are in the order of 20 m apart.
* Drill lines at Baggy Green have been drilled mainly
on a 50 m section spacing. Drillhole spacing on
section vary but on average are in the order of 20 m
to 50 m apart.
* Drill lines at White Tank have been drilled mainly on
a 50 m section spacing. Drillhole spacing on section
vary but on average are in the order of 10 m to 50 m
apart.
* Drill lines at Clarke North have been drilled mainly
on a 100 m section spacing. Drill lines at Clarke
South have been drilled irregularly mainly on a 50 m
to 70 m section spacing.
* Drillhole spacing is not expected to introduce any
sample bias.
* Data spacing is considered adequate for the gold and
saprolite hosted rare earth Mineral Resource
estimates.
============================================================ =======================================================================
Orientation
of data in * Whether the orientation of sampling achieves unbiased * REE mineralisation is expected to be controlled by
relation to sampling of possible structures and the extent to vertical weathering profiles.
geological which this is known, considering the deposit type.
structure
* If the relationship between the drilling orientation * REE results are reported as true width.
and the orientation of key mineralised structures is
considered to have introduced a sampling bias, this
should be assessed and reported if material.
* Vertical drill holes are expected to be perpendicular
to rare earth mineralisation.
* Gold results are not presented as true width but are
not considered to present any down dip bias.
============================================================ =======================================================================
Sample Pre 2021
security * The measures taken to ensure sample security. * Company staff collected or supervised the collection
of all laboratory samples. Samples were transported
by a local freight contractor.
* No suspicion of historic samples being tampered with
at any stage.
* Pulp samples were collected from Challenger
Geological Services and submitted to Intertek
Genalysis by Cobra Resources Employees.
2021 - Onward
* Transport of samples to Adelaide was undertaken by a
competent independent contractor. Samples were
packaged in zip tied polyweave bags in bundles of 5
samples at the drill rig and transported in larger
bulka bags by batch while being transported.
There is no suspicion of tampering of samples.
============================================================ =======================================================================
Audits or
reviews * The results of any audits or reviews of sampling * No laboratory audit or review has been undertaken.
techniques and data.
* Genalysis Intertek Laboratories Adelaide and Bureau
Veritas Laboratories, Adelaide are NATA (National
Association of Testing Authorities) accredited
laboratory, recognition of their analytical
competence.
============================================================ =======================================================================
Appendix 2: Section 2 Reporting of Exploration Results
Criteria JORC Code explanation Commentary
Mineral
tenement and * Type, reference name/number, location and ownership * The Clarke and Baggy Green Gold MRE and the Clarke-
land tenure including agreements or material issues with third Baggy Green Rare Earth MRE are located on EL 6131,
status parties such as joint ventures, partnerships, currently owned 100% by Peninsula Resources limited,
overriding royalties, native title interests, a wholly owned subsidiary of Andromeda Metals
historical sites, wilderness or national park and Limited.
environmental settings.
* The security of the tenure held at the time of * The Barns and White Tank Gold MRE are located on EL
reporting along with any known impediments to 5953, currently owned 100% by Peninsula Resources
obtaining a licence to operate in the area. limited, a wholly owned subsidiary of Andromeda
Metals Limited.
* Alcrest Royalties Australia Pty Ltd retains a 1.5%
NSR royalty over future mineral production from
licenses EL6001, EL5953, EL6131, EL6317 and EL6489.
* Baggy Green, Clarke, Laker and the IOCG targets are
located within Pinkawillinnie Conservation Park.
Native Title Agreement has been negotiated with the
NT Claimant and has been registered with the SA
Government.
* Aboriginal heritage surveys have been completed over
the Baggy Green Prospect area, with no sites located
in the immediate vicinity.
* A Native Title Agreement is in place with the
relevant Native Title party.
=============================================================== =======================================================================
Exploration
done by other * Acknowledgment and appraisal of exploration by other * On-ground exploration completed prior to Andromeda
parties parties. Metals' work was limited to 400 m spaced soil
geochemistry completed by Newcrest Mining Limited
over the Barns prospect.
* Other than the flying of regional airborne geophysics
and coarse spaced ground gravity, there has been no
recorded exploration in the vicinity of the Baggy
Green deposit prior to Andromeda Metals' work.
=============================================================== =======================================================================
Geology
* Deposit type, geological setting and style of * The gold and REE deposits are considered to be
mineralisation. related to the structurally controlled basement
weathering of epidote- pyrite alteration related to
the 1590 Ma Hiltaba/GRV tectonothermal event.
* Mineralisation has a spatial association with mafic
intrusions/granodiorite alteration and is associated
with metasomatic alteration of host rocks. Epidote
alteration associated with gold mineralisation is REE
enriched and believed to be the primary source.
* Rare earth minerals occur within the saprolite
horizon. XRD analysis by the CSIRO identifies kaolin
and montmorillonite as the primary clay phases.
* SEM analysis identified REE bearing mineral phases in
hard rock:
* Zircon, titanite, apatite, andradite and epidote.
* SEM analyses identifies the following secondary
mineral phases in saprock:
* Monazite, bastnaesite, allanite and rutile.
* Elevated phosphates at the base of saprock do not
correlate to rare earth grade peaks.
* Upper saprolite zones do not contain identifiable REE
mineral phases, supporting that the REEs are adsorbed
to clay particles.
* Acidity testing by Cobra Resources supports that
REDOX chemistry may act as a catalyst for Ionic and
Colloidal adsorption.
* REE mineral phase changes with varying saprolite
acidity and REE abundances support that a component
of REE bursary is ionically adsorbed to clays.
=============================================================== =======================================================================
Drillhole
Information * A summary of all information material to the * Exploration results are not being reported as part of
understanding of the exploration results including a the Mineral Resource area.
tabulation of the following information for all
Material drill holes:
o easting and northing of the drill hole collar
o elevation or RL (Reduced Level - elevation above sea
level in metres) of the drill hole
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 * In reporting Exploration Results, weighting averaging * Reported summary intercepts are weighted averages
methods techniques, maximum and/or minimum grade truncations based on length.
(eg cutting of high grades) and cut-off grades are
usually Material and should be stated.
* No maximum/ minimum grade cuts have been applied.
* 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 * No metal equivalent values have been calculated.
aggregations should be shown in detail.
* Rare earth element analyses were originally reported
* The assumptions used for any reporting of metal in elemental form and have been converted to relevant
equivalent values should be clearly stated. oxide concentrations in line with industry standards.
Conversion factors tabulated below:
Element Oxide Factor
Cerium CeO(2) 1.2284
Dy(2)
Dysprosium O(3) 1.1477
Er(2)
Erbium O(3) 1.1435
Eu(2)
Europium O(3) 1.1579
Gd(2)
Gadolinium O(3) 1.1526
Ho(2)
Holmium O(3) 1.1455
La(2)
Lanthanum O(3) 1.1728
Lu(2)
Lutetium O(3) 1.1371
Nd(2)
Neodymium O(3) 1.1664
Pr(6)
Praseodymium O(11) 1.2082
Sc(2)
Scandium O(3) 1.5338
Sm(2)
Samarium O(3) 1.1596
Tb(4)
Terbium O(7) 1.1762
Tm(2)
Thulium O(3) 1.1421
Y(2)
Yttrium O(3) 1.2699
Yb(2)
Ytterbium O(3) 1.1387
========
* The reporting of REE oxides is done so in accordance
with industry standards with the following
calculations applied:
* TREO = La(2) O(3) + CeO(2) + Pr(6) O(11) + Nd(2) O(3)
+ Sm(2) O(3) + Eu(2) O(3) + Gd(2) O(3) + Tb(4) O(7) +
Dy(2) O(3) + Ho(2) O(3) + Er(2) O(3) + Tm(2) O(3) +
Yb(2) O(3) + Lu(2) O(3) + Y(2) O(3)
* CREO = Nd(2) O(3) + Eu(2) O(3) + Tb(4) O(7) + Dy(2)
O(3) + Y(2) O(3)
* LREO = CeO(2) + Pr(6) O(11) + Nd(2) O(3) + Sm(2) O(3)
* HREO = Eu(2) O(3) + Gd(2) O(3) + Tb(4) O(7) + Dy(2)
O(3) + Ho(2) O(3) + Er(2) O(3) + Tm(2) O(3) + Yb(2)
O(3) + Lu(2) O(3) + Y(2) O(3)
* NdPr = Nd(2) O(3) + Pr(6) O(11)
* TREO-Ce = TREO - CeO(2)
* % Nd = Nd(2) O(3) / TREO
* %Pr = Pr(6) O(11) /TREO
* %Dy = Dy(2) O(3) /TREO
* %HREO = HREO/TREO
* %LREO = LREO/TREO
=============================================================== =======================================================================
Relationship
between * These relationships are particularly important in the * Preliminary results support unbiased testing of
mineralisation reporting of Exploration Results. mineralised structures.
widths and
intercept
lengths * If the geometry of the mineralisation with respect to
the drill hole angle is known, its nature should be * Previous holes drilled have been drilled in several
reported. orientations due to the unknown nature of
mineralisation.
* If it is not known and only the down hole lengths are
reported, there should be a clear statement to this
effect (eg 'down hole length, true width not known'). * Most intercepts are vertical and reflect true width
intercepts.
* Gold intercepts are considered oblique to
mineralisation.
=============================================================== =======================================================================
Diagrams
* Appropriate maps and sections (with scales) and * Relevant diagrams have been included within the
tabulations of intercepts should be included for any Mineral Resource report main body of text.
significant discovery being reported These should
include, but not be limited to a plan view of drill
hole collar locations and appropriate sectional
views. * Exploration results are not being reported for the
Mineral Resources areas.
=============================================================== =======================================================================
Balanced
reporting * Where comprehensive reporting of all Exploration * Not applicable - Mineral Resources are defined.
Results is not practicable, representative reporting
of both low and high grades and/or widths should be
practiced to avoid misleading reporting of
Exploration Results. * Exploration results are not being reported for the
Mineral Resource area.
=============================================================== =======================================================================
Other
substantive * Other exploration data, if meaningful and material, * Refer to previous announcements listed in RNS for
exploration should be reported including (but not limited to): reporting of REE results and metallurgical testing
data geological observations; geophysical survey results; and detailed gold intersections.
geochemical survey results; bulk samples - size and
method of treatment; metallurgical test results; bulk
density, groundwater, geotechnical and rock
characteristics; potential deleterious or
contaminating substances.
=============================================================== =======================================================================
Further work
* The nature and scale of planned further work (eg * Infill and extensional drilling aimed at growing the
tests for lateral extensions or depth extensions or Mineral Resource and converting Inferred Mineral
large-scale step-out drilling). Resources to Indicated Mineral Resources is planned.
* Diagrams clearly highlighting the areas of possible
extensions, including the main geological * Core drilling to collect geotechnical samples and
interpretations and future drilling areas, provided bulk density data is proposed for each resource area.
this information is not commercially sensitive.
=============================================================== =======================================================================
Appendix 3: Section 3 Estimation and Reporting of Mineral
Resources
Criteria JORC Code explanation Commentary
=============== ============================================================ ================================================================
Database
integrity * Measures taken to ensure that data has not been * The drillhole database is managed in-house by Cobra
corrupted by, for example, transcription or keying Resources using the Company's Seequent MXDeposit
errors, between its initial collection and its use database.
for Mineral Resource estimation purposes.
* Data validation procedures used. * It has been validated by MXDeposit specialists and
Cobra Resources.
* Data has been imported from current and historical
data files.
* Source data for historical drilling has been verified
as being drilled by Andromeda Metals and imported
directly from their Datashed database.
* Additional data validation, by Snowden Optiro,
included checking for out of range assay data and
overlapping or missing intervals.
=============== ============================================================ ================================================================
Site visits
* Comment on any site visits undertaken by the * Mrs C Standing (Snowden Optiro), acting as Competent
Competent Person and the outcome of those visits. Person for the REE MRE and the Barns, Baggy Green and
White Tank gold MREs and Ms J Tracey (Snowden Optiro)
acting as Competent Person for the Clarke gold MRE
have not visited the Wudinna Gold Project.
=============== ============================================================ ================================================================
Geological REE
interpretation * Confidence in (or conversely, the uncertainty of) the
geological interpretation of the mineral deposit. * REE mineralisation at Clarke and Baggy Green is
within saprolite and saprock horizons. There is
reasonable confidence in the geological
* Nature of the data used and of any assumptions made. interpretation of these horizons within the Mineral
Resource area.
* The effect, if any, of alternative interpretations on
Mineral Resource estimation.
* The saprolite and saprock horizons were interpreted
from geological logging data using Leapfrog Geo
* The use of geology in guiding and controlling Mineral software.
Resource estimation.
* The factors affecting continuity both of grade and Gold
geology.
* The Weathering Interpretation has been used to guide
the segregation of the mineralisation into primary
and supergene zones., which have been treated
separately in the estimation.
* A host lithology is relatively homogeneous, this has
not been used to guide the primary mineralisation
interpretation.
* The 2023 Mineral Resource estimates investigate an
alternative interpretation to the 2016 (Barns) and
2017 (White Tank and Baggy Green) Mineral Resource
estimates.
=============== ============================================================ ================================================================
Dimensions REE
* The extent and variability of the Mineral Resource * The area used to constrain the Mineral Resource (that
expressed as length (along strike or otherwise), plan is within 50 m of the drilling) extends for 2.0 km
width, and depth below surface to the upper and lower east-west by 3 km north-south. The mineralisation is
limits of the Mineral Resource. contained within a horizon of weathered saprolite and
saprock that has a thickness ranging from 1 to 70 m
and an average thickness of 54 m. The top of this
horizon extends from surface to 24 m.
Gold
* The Barns resource has an extent of 440 mN by 300 mE
and is up to 200 m deep.
* The White Tank resource has an extent of 300 along
strike by 150 m across strike and is up to 120 m deep
.
* The Baggy Green resource has two areas of
mineralisation with extents of 240 mN by 460 mE and
150 mN by 360 mE. The mineralisation extends to a
depth of 170 m.
* The Clarke resource has two areas of mineralisation
with extents of 450 mN by 170 mE in the north and 290
mN by 145 mE in the south. The mineralisation extends
to a depth of 190 m in the north and 140 m in the
south.
=============== ============================================================ ================================================================
Estimation and REE
modelling * The nature and appropriateness of the estimation * Data analysis and estimation was undertaken using
techniques technique(s) applied and key assumptions, including Snowden Supervisor and Datamine software.
treatment of extreme grade values, domaining,
interpolation parameters and maximum distance of
extrapolation from data points. If a computer
assisted estimation method was chosen include a * REE block grades were estimated using ordinary
description of computer software and parameters used. kriging (OK). Snowden Optiro considers OK to be an
appropriate estimation technique for this type of
mineralisation.
* The drillhole spacing within the Mineral Resource
area is generally 200 m by 200 m, however, areas of
tighter drilling and sampling occur proximal to gold
mineralisation where drill density is up to 25 m by
100 m.
* A maximum extrapolation distance of 50 m was applied
around the drilled area.
* Almost 77% of the sample intervals with assay data
are from samples of
* Statistical analysis indicated that outlier grades
are not present and top-cutting (grade-capping) was
not applied.
* Variogram analysis was undertaken to determine the
kriging estimation parameters used for OK estimation
of each REE.
* Variogram analysis was undertaken for each REE within
the saprolite and saprock. Within the mineralised
area of the saprolite maximum continuity ranges are
169 to 415 m E-W and 54 m to 160 m N-S. Within the
saprock maximum continuity ranges are 100 to 190 m
NE-SW and 115 m to 230 m NW-SE.
* Kriging neighbourhood analysis was performed to
determine the block size, sample numbers and
discretisation levels.
* Three estimation passes were used in block grade
estimation; the first search was based upon the La(2)
O(3) variogram ranges; the second search was two
times the initial search and the third search was up
to five times the initial search. The second and
third searches had reduced sample numbers required
for estimation. Almost 70% of the total La(2) O(3) ,
CeO(2) and Dy(2) O(3) block grades were estimated in
the first search pass, 23% within the second search
pass and the remaining 7% estimated in the third
search pass.
Gold
* Data analysis and estimation was undertaken using
Snowden Supervisor and Datamine software.
* Drillhole sample data was flagged from mineralised
interpretations.
* Mineralisation interpretations were extended to half
the drill spacing and up to 15 m along strike.
* Sample data was composited to a 1 m downhole length.
* The data has a moderate to high coefficient of
variation and high-grade outliers are present.
Top-cut grades of 4 to 15 g/t gold were applied to
the supergene mineralisation and 15 to 25 g/t gold to
the primary mineralisation. The top-cut grades were
selected by examining histograms, log probability
plots, population disintegration. The Clarke data has
a low coefficient of variation, so no top-cuts were
applied.
* No assumptions have been made regarding the recovery
of by-products.
* Only gold has been estimated.
* Gold mineralisation continuity was interpreted from
variogram analyses to have along strike (or
down-plunge) ranges of 53 m to 110 m, across strike
(or down-dip) ranges of 32 m to 80 m and vertical (or
perpendicular to the mineralisation plane) of 1.8 to
6 m.
* Estimation was carried out using ordinary kriging at
the parent block scale.
* The search ellipses were oriented within the plane of
the mineralisation.
* Three estimation passes were used; the first search
was based upon the variogram ranges in the three
principal directions; the second search was two times
the initial search and the third search was five to
six times the second search, with reduced sample
numbers required for estimation.
* At Barns, around 23% of the block grades were
estimated in the first pass, 47% in the second pass
and 30% in the third search pass. At White Tank,
around 85% of the block grades were estimated in the
first pass, 13% in the second pass and 2% in the
third search pass. At Baggy Green, around 40% of the
block grades were estimated in the first pass, 44% in
the second pass and 16% in the third search pass. At
Clarke, around 50% of the block grades were estimated
in the first pass, 38% in the second pass and 16% in
the third search pass.
* The estimated gold block model grades were visually
validated against the input drillhole data,
comparisons were carried out against the drillhole
data and by northing, easting and elevation slices.
=============== ============================================================ ================================================================
REE
* Description of how the geological interpretation was
used to control the resource estimates. * Geological interpretations of the top of basement,
saprock and saprolite horizons and the transported
cover sediments were completed using Leapfrog Geo
software. 3D interpretations of the saprock and
saprolite were used to constrain the Mineral Resource
estimate.
* Categorical indicator kriging (CIK) at the sub-cell
resolution was used to define REE mineralised (>100
ppm CeO(2) at a 45% threshold) blocks within the
saprolite horizon.
* The mineralised domains are considered geologically
robust in the context of the resource classification
applied to the estimate.
Gold
* The weathering interpretation has been used to guide
the segregation of the mineralisation into primary
and supergene zones., which have been treated
separately in the estimations.
* A host lithology is relatively homogeneous, this has
not been used to guide the primary mineralisation
interpretation.
=============== ============================================================ ================================================================
REE
* The availability of check estimates, previous * The January 2023 Mineral Resource estimate was used
estimates and/or mine production records and whether as a comparison to the Mineral Resource Update.
the Mineral Resource estimate takes appropriate
account of such data.
* A substantial increase in the tonnage of the resource
was achieved through changes to the Indicator kriging
parameters from the previous model.
Gold
* The Mineral Resources were estimated by Mining Plus
in 2016 (Barns) and 2017 (White Tank and Baggy
Green). These resources were interpreted using a
higher nominal cut-off grade and have different
lateral extents and mineralisation continuity
orientations. The global difference between these
estimates and the 2019 estimate is small (5% more
contained gold in the 2019 model) and the tonnage and
grade variances for the individual deposits are
consistent with the differences applied to the
interpretation and resource estimation process. The
2019 interpretation was updated with additional data
for the 2023 resource estimate.
* No previous gold Mineral Resource estimate has been
completed at Clarke.
============================================================ ================================================================
* The assumptions made regarding recovery of * No assumptions have been applied for the recovery of
by-products. by-products.
============================================================ ================================================================
* Estimation of deleterious elements or other non-grade * Deleterious elements were not considered for the
variables of economic significance (e.g. sulphur for Mineral Resource estimate.
acid mine drainage characterisation).
============================================================ ================================================================
REE
* In the case of block model interpolation, the block * Grade estimation was into parent blocks of 25 mE by
size in relation to the average sample spacing and 40 mN by 1mRL.
the search employed.
* Block dimensions were selected from kriging
neighbourhood analysis and reflect the variability of
the deposit as defined by the current drill spacing.
* Sub-cells to a minimum dimension of 5 mE by 10 mN by
0.5 mRL were used to represent volume.
* The drillhole spacing within the Mineral Resource
area is generally 200 m by 200 m, however, areas of
tighter drilling and sampling occur proximal to gold
mineralisation where drill density is up to 25 m by
100 m.
* Search ellipse dimensions were selected from
variogram analysis of La(2) O(3) .
Gold
* Block models were generated for Barns using a block
size of 10 mE by 10 mN on 4 m benches, for White Tank
using a parent block size of 10 mE by 20 mN on 4 m
benches, for Clarke using a parent block size of 25
mE by 25 mN on 3 m benches and for Baggy Green using
a parent block size of 10 mE by 10 mN on 5 m benches.
The parent blocks at Barns, White Tank and Baggy
Green were allowed to sub-cell down to 2 mE by 2 mN
by 0.5 mRL and at Clarke to 1 mE by 1 mN by 0.5 mRL
to more accurately represent the geometry and volumes
of the mineralisation horizons.
============================================================ ================================================================
* Selective mining units were not modelled.
* Any assumptions behind modelling of selective mining
units.
============================================================ ================================================================
REE
* Any assumptions about correlation between variables. * The REEs have moderate to high correlation
coefficients (0.57 to 1.0).
* All REEs (La(2) O(3) , CeO(2) , Pr(6) O(11) , Nd(2)
O(3) , Sm(2) O(3) , Eu(2) O(3) , Gd(2) O(3) , Tb(4)
O(7) , Dy(2) O(3) , Ho(2) O(3) , Er(2) O(3) , Tm(2)
O(3) , Yb(2) O(3) , Lu(2) O(3) and Y(2) O(3) ) were
estimated independently.
Gold
* Only gold was estimated.
============================================================ ================================================================
* The process of validation, the checking process used, * The estimated block model grades were:
the comparison of model data to drillhole data, and
use of reconciliation data if available.
o visually validated against the input drillhole data
o comparisons were carried out against the declustered
drillhole data and by northing, easting
and elevation slices.
o global statistical comparisons were carried out between the
mean input sample grade with
the estimated block grade for each domain.
* No production has taken place and thus no
reconciliation data is available.
=============== ============================================================ ================================================================
Cut-off REE
parameters * The basis of the adopted cut-off grade(s) or quality * The Mineral Resource has been reported above a
parameters applied. cut-off grade of TREO-Ce of 320 ppm and assumes
extraction by open pit mining.
* This cut-off grade was selected based on the
evaluation of other advanced clay hosted rare earth
Mineral Resources and the consideration that future
economic analysis of the cut-off grade is likely to
incorporate parameters that support extraction of the
underlying gold mineralisation.
Gold
* The Mineral Resource has been at a cut-off grade of
0.5 g/t Au, which is considered appropriate for the
likely open pit mining.
=============== ============================================================ ================================================================
Mining factors
or assumptions * Assumptions made regarding possible mining methods, * Planned extraction is by open pit mining.
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 * Mining factors such as dilution and ore loss have not
to consider potential mining methods, but the been applied.
assumptions made regarding mining methods and
parameters when estimating Mineral Resources may not
always be rigorous.
=============== ============================================================ ================================================================
Metallurgical REE
factors or * The basis for assumptions or predictions regarding * Preliminary work performed by Metallurgical Test Work
assumptions metallurgical amenability. It is always necessary as performed by the Australian Nuclear Science and
part of the process of determining reasonable Technology Organisation (ANSTO) demonstrated recovery
prospects for eventual economic extraction to potential via desorption/leaching conditions where:
consider potential metallurgical methods, but the
assumptions regarding metallurgical treatment
processes and parameters made when reporting Mineral
Resources may not always be rigorous. * At pH4, 0.5M (NH4)2SO4 as lixiviant REE recoveries
were generally below 10%
* At pH1, (NH4)2SO4 as lixiviant recoveries increased
with leach period. At 6 hours recoveries up to 34.7%
were achieved.
* Subsequent mineralogy and acidity testing has
identified zones that are likely to have a higher
component of ionic adsorption and are therefore
likely to lead to higher recoveries.
* The samples submitted were from gold bearing holes,
the pH conditions do not fit the criteria for REDOX
controlled ion adsorption.
* Further metallurgical studies are required to
progress an economic production flowsheet
Gold
* No metallurgical assumptions have been built into the
resource models.
* Test work undertaken to date has demonstrated gold
recoveries averaging 97.7% through a combination of
conventional gravity and cyanide leaching methods.
=============== ============================================================ ================================================================
Environmental
factors or * Assumptions made regarding possible waste and process * No assumptions have been made regarding waste and
assumptions residue disposal options. It is always necessary as process residue.
part of the process of determining reasonable
prospects for eventual economic extraction to
consider the potential environmental impacts of the
mining and processing operation.
=============== ============================================================ ================================================================
Bulk density REE
* Whether assumed or determined. If assumed, the basis * Average values have been calculated from the dataset.
for the assumptions. If determined, the method used,
whether wet or dry, the frequency of the measurements
,
the nature, size and representativeness of the * Bulk density measurements were calculated by water
samples. displacement method. Samples from the saprolite zone
were wrapped in cling film before testing.
* The bulk density for bulk material must have been
measured by methods that adequately account for void
spaces (vugs, porosity, etc), moisture and * Density was measured for 19 samples from the
differences between rock and alteration zones within saprolite zone. Values range from 1.26 t/m(3) to 2.1
the deposit. t/m(3) , with an average 1.6 t/m(3) . The average of
1.6 t/m(3) was used for tonnage estimation.
* Discuss assumptions for bulk density estimates used
in the evaluation process of the different materials.
Gold
* A total of 255 bulk density determinations have been
undertaken at Barns on either historical or recent
drillholes.
* The Barns deposit is 1 km north of White Tank and the
bulk density determinations are considered valid for
White Tank.
* A total of 185 bulk density determinations have been
undertaken at Baggy Green on either historical or
recent drillholes.
* Average values have been calculated from the dataset
and applied to the resource model based on the
oxidation/weathering state and lithologies in the
area
* Bulk density measurements were calculated by water
displacement method.
* Density values assigned to the resource models range
from 2.52 t/m3 to 2.73 t/m3.
=============== ============================================================ ================================================================
Classification REE
* The basis for the classification of the Mineral * The Mineral Resources have been classified as
Resources into varying confidence categories. Inferred on the basis of confidence in geological and
grade continuity and taking into account data quality,
data density and confidence in the grade estimation,
* Whether appropriate account has been taken of all using the modelled grade continuity.
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 assigned classification of Inferred reflects the
Competent Person's assessment of the accuracy and
confidence levels in the Mineral Resource estimate.
* Whether the result appropriately reflects the
Competent Person's view of the deposit.
Gold
* The Mineral Resources have been classified on the
basis of confidence in geological and grade
continuity and taking into account data quality, data
density and confidence in the grade estimation (using
the modelled grade continuity and the slope of the
regression as criteria).
* The Mineral Resources at White Tank, Clarke and Baggy
Green have been classified as Inferred.
* The majority (96%) of the Mineral Resource at Barns
is classified as Inferred. Indicated Mineral
Resources have been defined at Barns within five of
the primary mineralisation domains in areas where
drill spacing is generally 20 mE by 50 m or less and
the resources are above 20 mRL.
* The classification considers all available data and
quality of the estimate and reflects the Competent
Person's view of the deposit.
=============== ============================================================ ================================================================
Audits or
reviews * The results of any audits or reviews of Mineral * The Mineral Resources have been reviewed internally
Resource estimates. as part of normal validation processes by Snowden
Optiro.
* No external audit or review of the current Mineral
Resources have been conducted.
=============== ============================================================ ================================================================
Discussion of
relative * Where appropriate a statement of the relative * The assigned classification of Indicated and Inferred
accuracy/ accuracy and confidence level in the Mineral Resource reflects the Competent Persons assessment of the
confidence estimate using an approach or procedure deemed accuracy and confidence levels in the Mineral
appropriate by the Competent Person. Resource estimate. The statement relates to global
estimates of tonnes and grade.
* The statement should specify whether it relates to
global or local estimates, and, if local, state the
relevant tonnages, which should be relevant to * The statement relates to global estimates of tonnes
technical and economic evaluation. and grade.
* No production data exists for the Wudinna Project
gold or REE deposits.
============================================================ ================================================================
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END
UPDBIGDCUXGDGXL
(END) Dow Jones Newswires
September 07, 2023 02:00 ET (06:00 GMT)
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