TIDMGGP
RNS Number : 5933X
Greatland Gold PLC
21 December 2023
Greatland Gold plc (AIM: GGP)
E: info@greatlandgold.com
W: https://greatlandgold.com
: twitter.com/greatlandgold
NEWS RELEASE | 21 December 2023
Havieron Mineral Resource Estimate Update
Exceptional Mineral Resource growth continues at Havieron
THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION AS STIPULATED
UNDER THE UK MARKET ABUSE REGULATIONS. ON PUBLICATION OF THIS
ANNOUNCEMENT VIA A REGULATORY INFORMATION SERVICE, THIS INFORMATION
IS CONSIDERED TO BE IN THE PUBLIC DOMAIN .
Greatland Gold plc (AIM:GGP) ("Greatland" or the "Company") is
pleased to provide an updated Mineral Resource Estimate for
Havieron, its flagship gold-copper project located in the Paterson
Province of Western Australia.
Highlights
-- Estimated Mineral Resources (including Ore Reserves)
increased to 8.4Moz AuEq(1) (7.0Moz Au plus 275kt Cu), an increase
of 1.9M oz AuEq(1) from Greatland's 2022 Mineral Resource
Estimate:
- 29% increase in total gold equivalent content to 8.4M oz
AuEq(1) .
- 28% increase in total gold content to 7.0M oz Au.
-- Continuous mineralisation confirmed between the Eastern
Breccia and main Havieron Breccia domains with the definition of a
new high grade "Link Zone".
-- Drilling since Greatland's previous Mineral Resource Estimate
(MRE) update in March 2022 targeted the lower portion of the
mineral system and has increased the ounce per vertical metre
(OPVM) profile of these lower levels in line with the upper levels
of the deposit. The updated MRE now averages 7,900 OPVM (gold
equivalent) over the top 1,000 metres vertically.
-- The MRE update includes a 32% increase in contained gold
equivalent metal in the higher confidence Indicated MRE category,
which can now be considered in the updated Ore Reserve Estimate
that will be part of the Feasibility Study.
The updated MRE incorporates approximately 93,000 metres
additional drilling completed since the December 2021 drilling
cut-off for Greatland's March 2022 MRE.
Updated Mineral Resource Statement for the Havieron Deposit
(100%) (# *)
Classification Tonnage Grade Metal AuEq Metal
Mt Au (g/t) Cu (%) Au (Moz) Cu (Kt) AuEq (Moz)
-------- --------- ------- --------- -------- -----------
Indicated 50 2.6 0.33 4.1 168 5.0
-------- --------- ------- --------- -------- -----------
Inferred 81 1.1 0.13 2.9 107 3.4
================ ======== ========= ======= ========= ======== ===========
Total Mineral
Resource 131 1.7 0.21 7.0 275 8.4
-------- --------- ------- --------- -------- -----------
# Grades are reported to one (gold) and two (copper) decimal
places to reflect appropriate precision in the estimate, and this
may cause apparent discrepancies in totals. Results represent 100%
of the Mineral Resource for Havieron. Mineral Resources in the
South East Crescent and Link Zone are reported within a A$80 Net
Smelter Return(2) /t ("NSR(2) /t(") ) shell while Mineral Resources
in the Breccias are reported within a A$50 NSR(2) /t shell.
Resources are inclusive of Reserves.
* The updated Mineral Resource Estimate assumes selective mining
of the South East Crescent and Link Zone and bulk extraction in the
Breccias and are reported inside A$80 or A$50 NSR(2) /t shells
respectively.
Greatland Managing Director, Shaun Day, commented:
"We are delighted by the continued growth in the Havieron
Mineral Resource Estimate. The growth journey in the resource has
been very significant with the total gold equivalent Mineral
Resource content having increased from 4.4M oz in the October 2021
MRE, to 6.5M oz in the March 2022 MRE, and now to 8.4M oz in
2023.
The updated MRE now averages over 7,900 ounces per vertical
metre (gold equivalent) over 1,000 metres vertically, which is
testament to the quality of the Havieron ore body.
The high grade South East Crescent Zone Mineral Resource is now
defined over a 1,200 vertical metres (another 200 metres deeper
than in the March 2022 MRE update) and remains open at depth.
It was particularly pleasing to delineate additional ounces in
the lower third of the current extents of the mineralised system,
with around 70% of the MRE increase identified in the extensions to
this part of the ore body.
Another promising aspect of this update is the definition of the
Link Zone, between the Eastern Breccia and main Havieron Breccia;
whilst previously interpreted as separate domains, we have now
confirmed mineralisation is continuous and the breccias are now
defined as a singular continuous Breccia domain.
This update further demonstrates the quality and scale of
Havieron, and the compelling investment proposition for Greatland.
We are excited to see the impact of the significant growth in the
Indicated category on the updated Ore Reserve Estimate that will
underpin the Feasibility Study which is ongoing and expected to be
completed in 2024."
Important notes
Mineral Resource estimates are expressions of judgement based on
knowledge, experience and industry practice. They are also based on
a number of material assumptions (such as future commodity prices
and foreign exchange, cut off grades) which may prove to be
incorrect. Estimates which were valid when originally made may
alter significantly when new information or techniques becomes
available. In addition, by their very nature, Mineral Resource
estimates are imprecise and depend to some extent on
interpretations, which may prove to be inaccurate. Unless and until
actually mined and processed, no assurance can be given that any
estimated tonnage, grades and recovery levels will be realised.
This announcement and the updated Mineral Resource Estimate for
the Havieron Project contained in it have been prepared solely by
Greatland based on relevant available information and have not been
reviewed or approved by Greatland's Havieron joint venture partner,
Newmont Corporation (Newmont). Newcrest Operations Limited, a
subsidiary of Newmont, is the manager of the Havieron Joint Venture
and holds the majority 70% joint venture interest. Whilst the
information in this announcement pertaining to the estimation and
reporting of the Mineral Resources has been reviewed and approved
by a Competent Person(3) and the updated Mineral Resource estimate
has been independently reviewed by SRK Consulting (Australasia) Pty
Ltd(4) , the Company considers that it is possible that, in
preparing any future Mineral Resource estimate or Ore Reserve
estimate for the Havieron project, Newmont may adopt different
interpretations, assumptions, parameters or plans, or make
different judgements, to those used or made by Greatland in the
updated Mineral Resource Estimate contained in this
announcement.
Forward Looking Statements
This document includes forward looking statements and forward
looking information within the meaning of securities laws of
applicable jurisdictions. Forward looking statements can generally
be identified by the use of words such as "may", "will", "expect",
"intend", "plan", "estimate", "anticipate", "believe", "continue",
"objectives", "targets", "outlook" and "guidance", or other similar
words and may include, without limitation, statements regarding
estimated reserves and resources, certain plans, strategies,
aspirations and objectives of management, anticipated production,
study or construction dates, expected costs, cash flow or
production outputs and anticipated productive lives of projects and
mines.
These forward looking statements involve known and unknown
risks, uncertainties and other factors that may cause actual
results, performance and achievements or industry results to differ
materially from any future results, performance or achievements, or
industry results, expressed or implied by these forward-looking
statements. Relevant factors may include, but are not limited to,
changes in commodity prices, foreign exchange fluctuations and
general economic conditions, increased costs and demand for
production inputs, the speculative nature of exploration and
project development, including the risks of obtaining necessary
licences and permits and diminishing quantities or grades of
reserves, political and social risks, changes to the regulatory
framework within which Greatland operates or may in the future
operate, environmental conditions including extreme weather
conditions, recruitment and retention of personnel, industrial
relations issues and litigation.
Forward looking statements are based on assumptions as to the
financial, market, regulatory and other relevant environments that
will exist and affect Greatland's business and operations in the
future. Greatland does not give any assurance that the assumptions
will prove to be correct. There may be other factors that could
cause actual results or events not to be as anticipated, and many
events are beyond the reasonable control of Greatland. Forward
looking statements in this document speak only at the date of
issue. Greatland does not undertake any obligation to update or
revise any of the forward looking statements or to advise of any
change in assumptions on which any such statement is based.
Footnotes:
(1) The gold equivalent (AuEq) is based on assumed prices of
US$1,700/oz Au and US$3.75/lb Cu for Mineral Resource and
metallurgical recoveries based on block metal grade, reporting
approximately at 87% for Au and 87% for Cu which in both cases
equates to a formula of approximately AuEq = Au (g/t) + 1.6* Cu
(%). It is the company's opinion that all the elements included in
the metal equivalents calculation have a reasonable potential to be
recovered and sold.
(2) The Net Smelter Return ("NSR") is calculated using metal
prices of US$1,700/oz Au and US$3.75/lb Cu, metallurgical
recoveries based on block metal grade reporting approximately at
87% for Au and 87% for Cu, an USD:AUD exchange rate of 0.72, as
well as treatment and refining costs, payables and royalties.
(3) See Competent Person's Statement below for details.
(4) See Section titled "Independent Review of the Mineral
Resource Update".
Contact
For further information, please contact:
Greatland Gold plc
Shaun Day, Managing Director | info@greatlandgold.com
Nominated Advisor
SPARK Advisory Partners
Andrew Emmott / James Keeshan / Neil Baldwin | +44 203 368
3550
Corporate Brokers
Berenberg | Matthew Armitt / Jennifer Lee | +44 203 368 3550
Canaccord Genuity | James Asensio / George Grainger | +44 207
523 8000
SI Capital Limited | Nick Emerson / Sam Lomanto | +44 148 341
3500
Media Relations
UK - Gracechurch Group | Harry Chathli / Alexis Gore / Henry
Gamble | +44 204 582 3500
Australia - Fivemark Partners | Michael Vaughan | +61 422 602
720
About Greatland
Greatland is a mining development and exploration company
focused primarily on precious and base metals.
The Company's flagship asset is the world-class Havieron
gold-copper project in the Paterson Province of Western Australia,
discovered by Greatland and presently under development in joint
venture with world gold major, Newmont Corporation.
Havieron is located approximately 45km east of Newmont's
existing Telfer mine. The box cut and decline to the Havieron
orebody commenced in February 2021. Total development now exceeds
3,060m including over 2,110m of advance in the main access decline
(as at 22 November 2023). Subject to a positive feasibility study
and Decision to Mine, Havieron is intended to leverage the existing
Telfer infrastructure and processing plant. Access to Telfer will
de-risk the development and reduce capital expenditure.
Greatland has a proven track record of discovery and exploration
success and is pursuing the next generation of tier-one mineral
deposits by applying advanced exploration techniques in
under-explored regions. Greatland has a number of exploration
projects across Western Australia and in parallel to the
development of Havieron is focused on becoming a multi-commodity
miner of significant scale.
Further Information on the Updated Mineral Resource at
Havieron
Havieron Project
The project comprising the Havieron Au-Cu deposit is centred on
a deep magnetic anomaly 45km east of Telfer (Figure 1) in the
Paterson Province of Western Australia on the traditional lands of
the Martu people. The Project is held in a joint venture between
Greatland and Newcrest Operations Limited, a wholly owned
subsidiary of Newmont Corporation (Newmont), where Newmont
currently holds a 70% joint venture interest (Greatland 30%).
The Martu people and the Jamukurnu-Yapalikurnu Aboriginal
Corporation (JYAC, formerly WDLAC) are key project stakeholders.
The Martu hold exclusive possession native title rights and
interests over more than 140,000km(2) of land, including to all
points around the Telfer mine and Havieron Project. The Indigenous
Land Use Agreement (ILUA) with JYAC, centred on the Telfer mine,
extends to the Havieron project.
The Havieron project is located within granted Mining Lease
M45/1287 and has received the necessary regulatory approvals for
the construction of a box cut, exploration decline and certain
associated surface infrastructure. Construction commenced in
January 2021, and total development now exceeds 3,060m including
over 2,110m of advance in the main access decline (as at 22
November 2023), with the decline now at a depth of approximately
340 vertical metres with 80 vertical metres remaining to the base
of the Permian layer.
A pre-feasibility study for Havieron was completed in October
2021, and a feasibility study is ongoing with several value
enhancing options being assessed to maximise value and de-risk the
project.
Figure 1 . Location of the Havieron Project, approximately 45km
east of Telfer, Western Australia.
Drilling Overview
Drilling at Havieron commenced during mid-2019 with a total of
368 drill holes for 295,657m considered suitable to inform the MRE.
This total excludes non-exploration drilling (e.g. geotechnical,
hydrological, etc), and drilling considered not suitable (e.g.
holes which failed to reach target).
An additional 92,648m of drilling has been incorporated into
this updated MRE relative to the March 2022 MRE. This additional
drilling comprised a combination of growth and resource conversion
drilling, both of which have been extremely successful in
increasing the MRE.
The growth drilling has resulted in a 29% increase in contained
gold equivalent metal in this updated MRE, with additional ounces
defined within the Northern Breccia, Eastern Breccia and South East
Crescent. A new high grade zone has also been defined, the "Link
Zone" which confirms continuous mineralisation between the Northern
Breccia, South East Crescent and the Eastern Breccia.
The Resource conversion drilling targeted the upgrade of
previously defined Inferred South East Crescent MRE into the higher
confidence Indicated category, and has increased South East
Crescent Indicated MRE material from 26Mt to 36Mt, a greater than
30% increase to the previous March 2022 MRE. The importance of this
conversion is that the Indicated MRE category can underpin Ore
Reserve Estimates, whereas the Inferred MRE category cannot due to
its lower confidence.
Updated Mineral Resource Estimate
The updated MRE for the Havieron Deposit prepared by Greatland
(Table 1) ("Updated Mineral Resource") is based on drilling
completed to 6 June 2023, comprising 368 holes for 295,657m,
inclusive of 107 holes for 92,648m which are additional to the
drilling data incorporated in Greatland's March 2022 MRE released
on 3 March 2022.
Table 1: Updated Mineral Resource Estimate tabulation for the
Havieron deposit (100%) (# *)
Domain Classification Tonnage Grade Metal AuEq Metal
Mt Au Cu Au (Moz) Cu (Kt) AuEq (Moz)
(g/t) (%)
-------- ------- ----- --------- -------- -----------
South East
Crescent Indicated 36 3.0 0.42 3.5 150 4.2
============ ---------------- -------- ------- ----- --------- -------- -----------
Inferred 8 2.1 0.19 0.6 15 0.6
============================= ======== ======= ===== ========= ======== ===========
Link Zone Indicated 2 2.7 0.20 0.1 3 0.2
============ ---------------- -------- ------- ----- --------- -------- -----------
Inferred 5 1.4 0.26 0.2 12 0.3
============================= ======== ======= ===== ========= ======== ===========
Breccia Indicated 13 1.3 0.11 0.5 14 0.6
============ ---------------- -------- ------- ----- --------- -------- -----------
Inferred 68 0.9 0.12 2.1 79 2.5
============================= ======== ======= ===== ========= ======== -----------
Total Mineral Resource 131 1.7 0.21 7.0 275 8.4
-------- ------- ----- --------- -------- -----------
# Grades are reported to one (gold) and two (copper) decimal
places to reflect appropriate precision in the estimate, and this
may cause apparent discrepancies in totals. Results represent 100%
of the Mineral Resource for Havieron. Mineral Resources in the
South East Crescent are reported within a A$80 Net Smelter
Return(2) /tonne ("NSR/t") shell while Mineral Resources in the
Breccias are reported within a A$50 NSR/t shell. Resources are
inclusive of Reserves.
* The Updated Mineral Resource Estimate assumes selective mining
of the South East Crescent Zone and bulk extraction in the Breccias
and are reported inside A$80 or A$50 NSR(2) /t shells
respectively.
The updated MRE is reported as Indicated and Inferred Mineral
Resources in accordance with the 2012 edition of the Australasian
Code for Reporting of Exploration Results, Mineral Resources and
Ore Reserves (the JORC Code). The reported updated Mineral
Resources are inclusive of Ore Reserves. Refer to details in
Appendix 1 (JORC Table 1 - Sections 1 to 3) for information
relating to data collection and resource estimation.
The updated MRE represents a significant increase on the MRE
previously announced by Greatland in March 2022, including a:
-- 43% increase in total (Indicated plus Inferred) tonnes;
-- 28% increase in total gold ounces; and
-- 29% increase in total gold equivalent ounces.
Material differences between the Updated Mineral Resource and
the previously announced March 2022 Mineral Resource are as
follows:
-- A further 92,648 metres of infill drilling completed in the
approximately 18 months since December 2021 to 6 June 2023 when
surface drilling ceased.
-- Drilling has confirmed continuous mineralisation exists
between the Northern Breccia, South East Crescent and the Eastern
Breccia, in essence confirming that the Eastern Breccia forms part
of the same continuous breccia body that hosts the main Havieron
deposit. This has resulted in an increase in the breccia Resources
and the definition of a new high grade domain.
-- Drilling has provided adequate geological confidence to
define a new domain, the Link Zone, which is a moderately dipping
approximately 30m wide by 200m long zone of mineralisation that
extends northwards from the existing South East Crescent Zone at
the 4,000mRL down to the 3750mRL. This zone is interpreted to
encompass the high grade core of what has to date been referred to
as the Eastern Breccia.
-- Incrementally higher commodity prices have been used to
calculate the NSR values within the Mineral Resource estimate
(US$1,700/oz Au and US$3.75/lb Cu and a USD:AUD exchange rate of
0.72 for the updated MRE, compared with US$1,600/oz Au and
US$3.50/lb Cu and a USD:AUD exchange rate of 0.72 used in the March
2022 MRE) which have resulted in more Mineral Resources being
reported above the NSR cut-offs, noting however that due to the
high NSR value throughout most of the South East Crescent Zone this
change is not considered to have resulted in a material change in
the South East Crescent Zone Resources.
The increase in the Breccia Mineral Resources within the
Havieron Breccia is a combination of additional drilling and the
increased commodity prices.
The gold equivalent ounces per vertical metre (OPVM) of the
updated MRE is presented in Figure 2.
Figure 2 . Schematic 3D view looking northwest, depicting the
Greatland Havieron December 2023 MRE (left hand figure) with OPVM
charted to the right. The OPVM for the March 2022 MRE is also
charted (light grey dashed line). Drilling intensity (grey
horizontal bars) are a visual representation of the extent of
drilling that has informed the MRE by vertical level (not plotted
to the OPVM scale). The X axis scale (horizontal) is OPVM, while
the Y axis (vertical) is plotted as relative depth in metres RL
(Reduced Level).
Havieron Geology
The Havieron deposit comprises an ovoid shaped zone of variable
brecciation, alteration and sulphide mineralisation (the Breccia
Pipe). The mineralisation trends northwest to southeast with
approximate dimensions of 650m in length by 350m in width and
1,400m in depth along a northwest orientation. Bedding of the
surrounding country rocks outside of the Breccia Pipe strikes
northwest to southeast and dips approximately 40deg to the
southwest whereas inside the breccia zone the dip steepens greater
than 60deg to sub-vertical.
The Breccia Pipe includes unmineralised to low-grade crackle
breccia and a series of mineralised cemented breccias (Figure 3).
The highest-grade breccia occurs on the margins of the Breccia Pipe
and is termed the South East Crescent Zone. The Breccia Pipe also
includes relatively small dioritic intrusions with brecciated
contacts or wall rock clasts within the breccias. The diorite
intrusions are discontinuous; however, there appears to be a strong
spatial relationship between the presence and abundance of the
diorite dykes and/or clasts and the presence of gold and copper
mineralisation. The Breccia Pipe is intruded by a 20-30m wide,
north-northeast trending, steeply dipping post mineralisation
dolerite dyke.
Gold and copper mineralisation at Havieron consists of breccia,
vein and massive sulphide replacement gold and copper
mineralisation typical of intrusion-related styles of
mineralisation. Mineralisation is hosted by metasedimentary rocks
(meta-sandstones, meta-siltstones and meta-carbonate) and intrusive
rocks of an undetermined age. The main mineral assemblage contains
well developed pyrrhotite-chalcopyrite and lesser pyrite sulphide
mineral assemblages as breccia and vein infill, and massive
sulphide lenses.
Figure 3 . Plan view of the Havieron deposit geological model at
4600mRL (650m below surface)
The Indicated Mineral Resource estimate includes material from
the South East Crescent Zone, adjacent Breccias and a small portion
(2Mt) of the Link Zone that abuts the South East Crescent. The
Inferred Mineral Resource estimate is comprised of South East
Crescent Zone, Link Zone and portions of the broader Breccia Zones
that meet the criteria for classification.
Ordinary Kriging of 5m composites of gold and copper was
undertaken into 20m x 20m x 20m blocks and re-blocked into a
minimum of 4m x 4m x 4m blocks where required. The Mineral Resource
model was domained utilising the geological units defining the
South East Crescent Zone, Link Zone and the Cemented and Crackle
Breccias. Hard boundaries were used between the South East Crescent
Zone and Link Zones with the Breccia Zones and a transitional
boundary of 10m was used between the Breccia Zones. Kriging
Neighbourhood Analysis was used to define the search neighbourhood
for gold. All grades were estimated independently of each other and
composite data was capped prior to estimation. Within the Havieron
Breccia complex over 99% of the resource estimation is based
entirely on interpolation with less than 1% extrapolated blocks
(which Greatland defines as the nearest informing composite being
more than 30m away and estimated by data from fewer than 4
drillholes). The Mineral Resource model was validated via visual,
statistical, and geostatistical methods.
The Indicated and Inferred Mineral Resource estimate has been
constrained using appropriate drill hole data spacing parameters
and geological control. Resource classification is based on a
combination of geological confidence, average weighted distance and
slope of regression statistics for estimated gold grades, and
economic constraints (NSR). The Indicated Mineral Resource
classification within the South East Crescent Zone and Link Zone is
reported based on the evaluation of nominal thresholds of the
average weighted distance (45m) and slope of regression (>0.6)
and with blocks lying within an A$80 NSR/t shell. The Inferred
Mineral Resource classification within the South East Crescent Zone
and Link Zone is reported based on the evaluation of nominal
thresholds of the average weighted distance (75m) and slope of
regression (>0.3) and with blocks lying within an A$80 NSR/t
shell.
The Indicated Mineral Resource classification within the
Breccias is reported on the evaluation of nominal thresholds of the
average weighted distance (30m) and slope of regression (>0.6)
within an A$50 NSR/t value shell with no internal selectivity,
which assumes bulk mining and therefore includes internal waste.
The Inferred Mineral Resource classification within the Breccias is
reported on the evaluation of nominal thresholds of the average
weighted distance (75m) and slope of regression (>0.3) within an
A$50 NSR/t value shell with no internal selectivity, which assumes
bulk mining and therefore includes internal waste.
The NSR uses metal prices of US$1,700/oz Au and US$3.75/lb Cu,
metallurgical recoveries based on block metal grade, reporting
approximately 87% for Au and 87% for Cu, a USD:AUD exchange rate of
0.72, as well as treatment and refining costs, payables and
royalties, similar to those applied for the March 2022 MRE.
Reasonable prospects for eventual economic extraction have been
assessed through ongoing mining and processing studies which
suggest that selective underground mining would be appropriate for
exploitation of the South East Crescent Zone, while less selective
underground mining would be appropriate for the exploitation of the
mineralised Breccia Zones. There are no known environmental,
social, governmental / regulatory or legal barriers to declaring
this Mineral Resource.
Competent Person's Statement
Information in this announcement pertaining to the Reporting of
Mineral Resources is based on information compiled and approved by
Mr Michael Thomson, a Member of the Australian Institute of
Geoscientists (AIG), who has more than 20 years relevant industry
experience. Mr Thomson is a full-time employee of the Company and
has a financial interest in Greatland. Mr Thomson has sufficient
experience relevant to the style of mineralisation, type of deposit
under consideration, and to the activity which he is undertaking to
qualify as a Competent Person as defined by the 2012 Edition of the
Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves (the JORC Code) and under the AIM Rules
- Note for Mining and Oil & Gas Companies, which outline
standards of disclosure for mineral projects. Mr Thomson consents
to the inclusion in this announcement of the matters based on this
information in the form and context in which it appears.
Independent Review of the Mineral Resource Update
SRK Consulting (Australasia) Pty Ltd has completed an
independent technical assessment of the Updated Mineral Resource
Estimate completed by Greatland for the Havieron deposit. As part
of that assessment SRK reviewed the Resource modelling methods and
parameters and found them to be reasonable and to take into
consideration all of the current exploration data and levels of
technical knowledge of the Havieron deposit.
SRK considers that the Mineral Resources have been reported in
accordance with guidelines and principles outlined in the 2012
edition of the Australasian Code for the Reporting of Exploration
Results, Mineral Resources and Ore Reserves (the JORC Code, 2012
edition).
Appendix - JORC Code, 2012 Edition - Table 1
Section 1 - Sampling Techniques and Data
Criteria Commentary
================== ====================================================================
Sampling Samples are obtained from core drilling in Proterozoic
techniques basement lithologies. PQ-HQ and NQ diameter core was
drilled in 6m runs. Core was cut using an automated core-cutter
and half core sampled at nominal 1m intervals with breaks
for major geological changes. Sampling intervals range
from 0.2 - 2.0m. Cover sequences were not sampled.
================== ====================================================================
Drilling The Permian Paterson Formation cover sequence was drilled
techniques using mud rotary drilling. Depths of cover typically
observed as approximately 420m vertically below surface.
Steel casing was emplaced to secure the pre-collar.
Core drilling was advanced from the base of the cover
sequence with PQ3, HQ3 and NQ2 diameter coring configuration.
Core from inclined drill holes is oriented on 3m and
6m runs using an electronic core orientation tool (Reflex
ACTIII or equivalent). At the end of each run, the bottom
of hole position is marked by the driller, which is later
transferred to the whole drill core run length with a
bottom of hole reference line.
================== ====================================================================
Drill sample Core recovery is systematically recorded from the commencement
recovery of coring to end of hole, by reconciling against driller's
depth blocks in each core tray with data recorded in
the database. Drillers depth blocks provided the depth,
interval of core recovered, and interval of core drilled.
Core recoveries were typically 100%, with isolated zones
of lower recovery.
Cover sequence drilling using the mud-rotary drilling
technique does not yield recoverable samples.
================== ====================================================================
Logging Geological logging recorded qualitative descriptions
of lithology, alteration, mineralisation, veining, and
structure for all core drilled, including orientation
of key geological features.
Geotechnical measurements were recorded including Rock
Quality Designation (RQD) fracture frequency, solid core
recovery and qualitative rock strength measurements.
Magnetic susceptibility measurements were recorded every
metre. The bulk density of selected drill core intervals
was determined at site on whole core samples.
All geological and geotechnical logging was conducted
at the Havieron site.
Digital data logging was captured on diamond drill core
intervals only, and all data validated and stored in
an acQuire database.
All drill cores were photographed, prior to cutting and/or
sampling the core.
The logging is of sufficient quality to support Mineral
Resource estimates.
================== ====================================================================
Sub-sampling Sampling, sample preparation and quality control protocols
techniques are considered appropriate for the material being sampled.
and sample Core was cut and sampled at the Havieron core processing
preparation facility. Half core samples of between 0.2 and 2.0 m
were collected in pre-numbered calico bags and grouped
in plastic bags for dispatch to the laboratory. Sample
weights typically varied from 0.5 to 7kg. Sample sizes
are considered appropriate for the style of mineralisation.
Drill core samples were freighted by air and road to
the laboratory.
Sample preparation was conducted at the independent I
SO17025 accredited Intertek Laboratory, Perth (Intertek).
Samples were dried at 105(o) C, and crushed to 95% passing
4.75mm, and the split to obtain up to 3kg sub-sample,
which was pulverised (using an LM5 ring pulveriser) to
produce a pulped product with the minimum standard of
95% passing 106<MU>m. Routine grind size analysis is
conducted.
Duplicate samples were collected from crush and pulp
samples at a rate of 1:20. Duplicate results show an
acceptable level of variability for the material sampled
and style of mineralisation.
Periodic size checks (1:20) for crush and pulp samples
and sample weights are provided by the laboratory and
recorded in the acQuire database.
================== ====================================================================
Quality of Assaying of drill core samples was conducted at Intertek.
assay data All samples were assayed for 48 elements using a 4-acid
and laboratory digestion followed by ICP-AES/ICP-MS determination (method
tests 4A/MS907), which is considered to provide a total assay
for copper. Gold analyses were determined by 50g fire
assay with AAS finish (method FA50N/AA), which is considered
to provide a total assay for gold.
Sampling and assaying quality control procedures consisted
of inclusion of certified reference material (CRMs),
coarse residue and pulp duplicates with each batch (at
least 1:20).
Assays of quality control samples were compared with
reference samples in an acQuire database and verified
as acceptable prior to use of data from analysed batches.
Laboratory quality control data, including laboratory
standards, blanks, duplicates, repeats and grind size
results are captured in the acQuire database and assessed
for accuracy and precision for recent data.
Extended quality control programmes including pulp samples
submitted to an umpire laboratory and combined with more
extensive re-submission programmes have been completed.
Analysis of the available quality control sample assay
results indicates that an acceptable level of accuracy
and precision has been achieved and the database contains
no analytical data that has been numerically manipulated.
The assaying techniques and quality control protocols
used are considered appropriate for the data to be used
for reporting exploration drilling results and for use
in resource and reserve estimation.
================== ====================================================================
Verification Sampling intervals defined by the geologist are electronically
of sampling assigned sample identification numbers prior to core
and assaying cutting. Corresponding sample numbers matching pre-labelled
calico bags are assigned to each interval.
All sampling and assay information were stored in a secure
acQuire database with restricted access.
Electronically generated sample submission forms providing
the sample identification number accompany each submission
to the laboratory. Assay results from the laboratory
with corresponding sample identification are loaded directly
into the acQuire database.
Assessment of reported significant assay intervals was
verified by re-logging of diamond drill core intervals
and assessment of high resolution core photography. The
verification of significant intersections has been completed
by company personnel and the Competent Person/Qualified
Person.
No adjustments are made to assay data, and no twinned
holes have been completed.
There are no currently known drilling, sampling, recovery,
or other factors that could materially affect the accuracy
or reliability of the data.
================== ====================================================================
Location Drill collars were surveyed using real time kinematic
of data points (RTK) GPS, with an accuracy of +/-10mm E/N and +/-20mm
RL, for all drill holes reported.
Drill rig alignment was attained using an electronic
azimuth aligner. Downhole survey was collected at 6-12m
intervals in the cover sequence, and every 6 to 30m in
diamond drill core segments of the drill hole using single
shot (Axis Mining Champ Gyro). The single shot surveys
have been validated using continuous survey to surface
(Axis Mining Champ) along with a selection of drill holes
re-surveyed by an external survey contactor using a DeviGyro
tool - confirming sufficient accuracy for downhole spatial
recording.
A LIDAR survey was completed over the project area in
Nov 2019 which was used to prepare a DEM / topographic
model for the project with a spatial accuracy of +/-
0.1m vertical and +/- 0.3m horizontal. The topography
is generally low relief to flat, elevation within the
dune corridors in ranges between 250-265m Australian
Height Datum (AHD) steepening to the southeast. All collar
coordinates are provided in the Geocentric Datum of Australian
(GDA20 Zone 51). All relative depth information is reported
in AHD +5000m.
================== ====================================================================
Data spacing Within the South East Crescent and Breccia zone drill
and distribution hole spacing ranges from 50 to 100m, to 50 by 50m within
the resource extents. Outside the initial resource boundary
drill hole spacing ranges from 50 to 200m in lateral
extent within the breccia zone over an area of 2km(2)
. The data spacing is sufficient to establish the required
degree of geological and grade continuity.
Significant assay intercepts remain open. Further drilling
is required to determine the extent of currently defined
mineralisation. Drilling intersects mineralisation at
various angles.
================== ====================================================================
Orientation Drill holes exploring the extents of the Havieron mineral
of data in system intersect moderately dipping carbonate and siliciclastic
relation sedimentary facies, mineralised breccia and sub-vertical
to geological intrusive lithologies. Geological modelling has been
structure interpreted from historic and Newcrest Operations Limited
(Newcrest) drill holes.
Variable brecciation, alteration and sulphide mineralisation
is observed within a footprint with dimensions of 650m
x 350m trending in a north west orientation and over
1400m in vertical extent below cover.
The subvertical southeast high grade arcuate crescent
sulphide zone has an average thickness of >20m and has
been defined over a strike length of up to 550m, and
to over 1,000m in vertical extent below cover.
Drilling direction is oriented to intersect the steeply
dipping high grade sulphide mineralisation zones at an
intersection angle of greater than 40 degrees. The drilled
length of reported intersections is typically greater
than true width of mineralisation.
================== ====================================================================
Sample security The security of samples is controlled by tracking samples
from drill rig to database.
Drill core was delivered from the drill rig to the Havieron
core yard every shift. On completion of geological and
geotechnical logging, core processing was completed by
Newcrest personnel at the Havieron facility.
High resolution core photography and cutting of drill
core was undertaken at the Havieron core processing facilities.
Samples were freighted in sealed bags by air and road
to the Laboratory, and in the custody of Newcrest representatives.
Sample numbers are generated directly from the database.
All samples are collected in pre-numbered calico bags.
Verification of sample numbers and identification is
conducted by the laboratory on receipt of samples, and
sample receipt advise issued to Newcrest.
Details of all sample movements are recorded in a database
table. Dates, Hole ID sample ranges, and the analytical
suite requested are recorded with the dispatch of samples
to analytical services. Any discrepancies logged at the
receipt of samples into the analytical services are validated.
================== ====================================================================
Audits or Internal reviews of core handling, sample preparation
reviews and assays laboratories were conducted on a regular basis
by both project personnel and owner representatives.
In the Competent Person's opinion, the sample preparation,
security and analytical procedures are consistent with
current industry standards and are entirely appropriate
and acceptable for the styles of mineralisation identified
and will be appropriate for use in the reporting of exploration
results and Mineral Resource estimates. There are no
identified drilling, sampling or recovery factors that
materially impact the adequacy and reliability of the
results of the drilling program in place at Havieron.
================== ====================================================================
Section 2 Reporting of Exploration Results
Criteria Commentary
======================== ============================================================================================
Mineral tenement Havieron is entirely contained within mining tenement
and land M45/1287, which is owned by the Havieron Joint Venture
tenure status participants, being Greatland Pty Ltd (Greatland) and
Newcrest, a wholly owned subsidiary of N ewmont Corporation
(N ewmont ). Newcrest has previously entered into a Joint
Venture Agreement (effective 30 November 2020) and Farm-In
Agreement (effective 12 March 2019) with Greatland and
Greatland Gold plc. Newcrest is the manager of the Havieron
Joint Venture and holds a 70% interest (Greatland holds
a 30% interest).
Newcrest and Jamukurnu-Yapalikurnu Aboriginal Corporation
(JYAC, formerly WDLAC) are parties to an ILUA which relates
to the access and use of native title land for Newcrest's
current operations at the Telfer mine and its activities
within a 60km radius around Telfer, and following the
formation of the Havieron Joint Venture, applies to Greatland
and Newcrest in respect of their activities at Havieron.
The mining tenement M45/1287 wholly replaces the 12 sub-blocks
of exploration tenement E45/4701 (former part of the
exploration tenement on which the Havieron Project is
based) and was granted on 10 September 2020.
======================== ============================================================================================
Exploration Newcrest completed six core holes in the vicinity of
done by other Havieron from 1991 to 2003. Greatland completed drill
parties targeting and drilling of nine Reverse Circulation (RC)
drill holes with core tails for a total of approximately
6,800m in 2018. Results of drilling programs conducted
by Greatland have previously been reported on the Greatland
website.
Drilling has defined an intrusion-related mineral system
with breccia and massive sulphide-hosted higher-grade
gold-copper mineralisation.
======================== ============================================================================================
Geology Havieron is located within the north-western exposure
of the Palaeo-Proterozoic to Neoproterozoic Paterson
Orogen (formerly Paterson Province), 45 km east of the
Telfer mine. The Yeneena Supergroup hosts the Havieron
prospect and consists of a 9km thick sequence of marine
sedimentary rocks and is entirely overlain by approximately
420m of Phanerozoic sediments of the Paterson Formation
and Quaternary aeolian sediments.
Gold and copper mineralisation at Havieron consist of
breccia, vein and massive sulphide replacement gold and
copper mineralisation typical of intrusion-related and
skarn styles of mineralisation. Mineralisation is hosted
by metasedimentary rocks (meta-sandstones, meta-siltstones
and meta-carbonate) and intrusive rocks of an undetermined
age. The main mineral assemblage contains well developed
pyrrhotite-chalcopyrite and pyrite sulphide mineral assemblages
as breccia and vein infill, and massive sulphide lenses.
The main mineralisation event is associated with
amphibole-carbonate-biotite-sericite-chlorite
wall rock alteration. Drilling has partially defined
the extents of mineralisation which are observed over
650m by 350m within an arcuate shaped mineralised zone,
and to depths of up to 1400m below surface.
======================== ============================================================================================
Drill hole No assay result reported in this announcement.
Information
======================== ============================================================================================
Data aggregation No assay result reported in this announcement.
methods
======================== ============================================================================================
Relationship No assay result reported in this announcement.
between mineralisation
widths and
intercept
lengths
======================== ============================================================================================
Diagrams As provided.
======================== ============================================================================================
Balanced Earlier results of exploration programs conducted by
reporting Newcrest and Greatland have previously been reported.
======================== ============================================================================================
Other substantive Nil
exploration
data
======================== ============================================================================================
Further work The most recent round of growth drilling has been completed.
No further drilling in planned until underground drill
access has been established.
======================== ============================================================================================
Section 3 - Estimation and Reporting of Mineral Resources
Criteria Commentary
---------------- ------------------------------------------------------------------------------------------------
Database Data logged or received by Newcrest are stored in an SQL
integrity acQuire(TM) database. Assay and geological data are electronically
loaded into acQuire and the database is replicated in
Newcrest's centralised database system in Melbourne. In-built
validation tools are used in the acQuire(TM) database
and data loggers are used to minimise keystroke errors,
flag potential errors and validate against internal library
codes. Regular reviews of data quality are conducted by
site and corporate teams prior to resource estimation.
Final surveyed collars are checked against the original
collar GPS pickup and the Lidar topographic surface. Downhole
surveys are checked visually and statistically for outliers.
Assay data is checked for negative, extreme, missing and
overlapping samples. Below detection assay values are
set to half the lower detection limit for estimation.
Geological domains are reviewed against core photography,
geochemistry and Corescan data and checked for overlaps
and missing intervals. Data that is found to be in error
is investigated and corrected where possible. If the data
cannot be corrected it is removed from the data set used
for resource modelling and estimation.
---------------- ------------------------------------------------------------------------------------------------
Newcrest provides Greatland with a 'data pack' approximately
every 6 weeks containing new drilling data and assay results.
Assay data is imported into Greatland's SQL database directly
from the Laboratory assay reports, including laboratory
QA/QC data.
---------------- ------------------------------------------------------------------------------------------------
Site visits The Competent Person for Mineral Resources visited Havieron
site in November 2022, during which he inspected drilling,
sampling, logging, selected drill core, the core cutting
facility and is satisfied that the data and information
generated and is suitable for resource estimation and
subsequent reporting in compliance with the JORC Code
(2012).
---------------- ------------------------------------------------------------------------------------------------
Geological The geology model defines several mineralised zones, including
interpretation a Crescent Zone (containing the sulphide rich material
in the area named the "South East Crescent Zone") and
several Breccia types (Cemented Breccia (CB) and Crackle
Breccia (CBX)), and several unmineralised zones (Dolerite
Dyke, Calc-silicate country rocks, Permian sequence and
Cover). In addition, a new sulphide rich Zone, the "Link
Zone" has been defined in the lower sections of the mineral
system (3750 -4000mRL). These zones are based on grouped
primary logging domain codes interpreted from drill cores,
mineralogical logs and assay data. G reatland has incorporated
much of the previously reported Actinolite Breccia (ACB)
zone into its CB and CBX zones on the bases of their similarity
of spatial grade distributions and geometries, and absence
of sharp contrasts in gold and copper grades between them.
These zones have been modelled into 3D solids in Leapfrog
Geo 6.1 using vein, intrusive and erosional implicant
models.
---------------- ------------------------------------------------------------------------------------------------
The increased presence of northwest trending, steeply
dipping diorites in the breccias corresponds to an increase
in grade. Due to their dispersed nature within the breccia
these diorites have not been modelled, Their impact is
represented to a large extent by the choice of search
neighbourhood parameters.
---------------- ------------------------------------------------------------------------------------------------
The confidence in the location and geometry of the South
East Crescent Zone is generally high but decreases as
the informing data becomes sparse.
------------------------------------------------------------------------------------------------
The confidence in the location and geometry of the breccias
in the Havieron Breccia zones is variable, but considered
moderate in the densely drilled areas. The confidence
decreases markedly as the scale is decreased. As such,
this model is not a suitable basis for assessing selective
mining options for these zones.
------------------------------------------------------------------------------------------------
The confidence in the location and geometry of the Dolerite
Dyke, Calc-Silicate sediments and Base of Permian is very
high.
------------------------------------------------------------------------------------------------
The interpretation is based mainly on drill hole logging
and assay data as previously described in this Table.
In addition, Greatland acknowledges the extensive ground
work undertaken by Newcrest in identifying and interpreting
the geology and agrees with the broad geological domains
defined in the geological model.
------------------------------------------------------------------------------------------------
The South East Crescent Zone is generally very well defined,
and it is difficult to generate an alternative, plausible
and materially different interpretation from the available
data. The zone is typically intersected where expected
by new drilling. Towards the base of the current drilling
alternate interpretations of the South East Crescent are
plausible with the Link Zone possibly being a continuation
of the South East Crescent, with further drilling required
to confirm this relationship.
The "Link Zone" is moderately well drilled in places with
the grade profile between this zone and the adjacent breccias
suggesting that the domain is valid. Several estimation
quality indicators (SOR, Kriging efficiencies, closest
distance and average distance) suggest overall that the
estimate in the Link Zone is well-informed. Currently
the vast majority of this material has been classified
as inferred until further work is completed.
------------------------------------------------------------------------------------------------
The Breccia zones are reasonably well defined at a large
scale but are much less well defined at the short scale
owing to their low geological and grade continuity. However,
it is difficult to generate alternative, plausible and
materially different zones from the available data.
------------------------------------------------------------------------------------------------
Geological controls on estimation are implicit in the
domaining and the nature of their boundaries. In addition,
the northwest striking , steeply dipping trend of the
diorites is reflected in the choice of search parameters
within the breccia.
------------------------------------------------------------------------------------------------
Factors affecting continuity both of grade and geology
include the change in type and intensity of brecciation
and breccia fill (veining) across the Havieron system.
Greatland considers the brecciation is logged and modelled
in sufficient detail to be used in the estimation.
---------------- ------------------------------------------------------------------------------------------------
Dimension Variable brecciation, alteration and sulphide mineralisation
are observed with a footprint with dimensions of 650m
x 350m trending in a north west orientation and over 1100m
in vertical extent below 420m of cover. The South East
Crescent Zone Mineral Resource extents are 550m in unfolded
plan section, between 5-40m true width and 1200m in vertical
extent, mineralisation remains open at depth.
---------------- ------------------------------------------------------------------------------------------------
The Link zone begins at approximately the 4000mRL (1250m
below surface) and has currently been defined down to
3750mRL. The Link Zone is a moderately dipping approximately
30m wide by 200m long zone of mineralisation.
---------------- ------------------------------------------------------------------------------------------------
The Breccia Mineral Resource occurs as a 50-100m sleeve
marginal to the South East Crescent Zone Mineral Resource
and also with pockets within the greater breccia pipe.
These pockets within the core of the breccia trend from
the north west near the top of the system, downwards towards
the north east in the lower levels of the system and potentially
connect with the Eastern Breccia material.
---------------- ------------------------------------------------------------------------------------------------
Estimation Greatland used nominal 5m composites on a domain-wise
and modelling basis for variography, search neighbourhood optimisation
techniques and estimation, with the actual composite length for each
intersection adjusted to minimise the amount of 'short
tails'.
---------------- ------------------------------------------------------------------------------------------------
A geostatistical review using the data up to 6 July 2023
confirmed that the gold and copper grade distributions
showed that the Breccia Zones are moderately diffusive
in nature, and the South East Crescent Zone is relatively
weakly diffusive in nature. Even though the South East
Crescent Zone is weakly diffusive in nature, Ordinary
Kriging (OK) is considered an appropriate estimator given
the geological setting, geological observations from the
logging data, geometry of the domain and its tenor relative
to the likely operating cut-off grade.
---------------- ------------------------------------------------------------------------------------------------
Composite data for gold, copper, bismuth, nickel, cobalt,
iron, sulphur, calcium and magnesium were declustered
using a cell-declustering approach for each domain.
------------------------------------------------------------------------------------------------
Outlier grades were dealt with through top cutting for
each variable on a domain-basis, with top-cuts generally
around the 99th percentile of the declustered distribution.
------------------------------------------------------------------------------------------------
Greatland evaluated an 'automated unfolding' method (undertaken
in Micromine(tm) ) for the South East Crescent Zone that
yielded robust variograms and relatively high confidence
in the variogram models and estimates of gold and copper
for this zone (note that the model blocks were also unfolded,
with the result that parent-cell estimation could not
be used for this zone). This method uses an underlying
controlling surface that represents the mid-surface of
the solid that was created by Greatland.
------------------------------------------------------------------------------------------------
Greatland also used a 'trend model' method (undertaken
in Micromine(tm) ) to guide the estimation of grade and
density for the South East Crescent, Link Zone and Breccia
zones. This approach generates a locally varying anisotropy
(LVA) for each block that orients the search ellipse and
variogram model to the local geometry. This approach does
not explicitly unfold the composite data or block model,
but does honour parent blocks during the estimation.
------------------------------------------------------------------------------------------------
Greatland evaluation of the South East Crescent Zone via
the "automated unfolding" method and trend model method
resulted in an estimate with less than 1% variance in
contained metal. Each method has merit but due to the
limitation of the unfolding method being unable to estimate
into the parent block and significant sub-celling present
due to the geometry of the SE Crecent the LVA method of
estimation was adopted as the preferred method for estimation.
Both approaches will continue to be evaluated in future
estimates.
------------------------------------------------------------------------------------------------
A quantitative kriging neighbourhood analysis (QKNA) was
undertaken on gold for each domain with the aim to maximise
the slope-of-regression and kriging efficiency, whilst
minimising the percentage of negative weights. Large search
radii were used but with maximum number of points constraints
to meet these aims. Search ellipsoids were aligned with
variogram model ellipses.
------------------------------------------------------------------------------------------------
All estimates used a hard boundary between the South East
Crescent Zone and Link Zone with all other domains. A
transitional boundary of 10m was used between the Cemented
and Crackle Breccias to reflect the variable nature of
this boundary. Only blocks 5m either side of the Cement
and Crackle Breccia boundaries were allowed to utilise
the transitional boundary data, the remainder of the breccia
was estimated from only data within their respective domains.
------------------------------------------------------------------------------------------------
Density was estimated by OK on a domain-wise basis Whilst
density is most strongly correlated with iron (Fe) and,
to a lesser extent, sulphur (S), it is also significantly
influenced by the domain, with the South East Crescent
domain capturing the high iron and sulphur grades, and
thus density, very well.
------------------------------------------------------------------------------------------------
Gold and copper were estimated with 2 passes, less than
0.05% of the total material classified was estimated during
the second pass estimate. All other elements (bismuth,
cobalt, nickel, sulphur, iron, calcium, magnesium) and
density were estimated using two-passes. In addition,
a higher grade bismuth domain, within the South East Crescent
was defined to estimated bismuth separately.
------------------------------------------------------------------------------------------------
Less than 1% of the Mineral Resource estimate is based
on composites with a closest distance to the block of
more than 30m and data from less than 4 holes, which Greatland
has used to define extrapolation. These blocks are mainly
on the edges of the domain.
------------------------------------------------------------------------------------------------
Grades and density were estimated in Micromine 2023(tm)
software.
------------------------------------------------------------------------------------------------
The sensitivity of the South East Crescent Zone gold estimates
to various top cut, search neighbourhood and variogram
model parameters was assessed with variations commensurate
with that implied by the resource classification.
------------------------------------------------------------------------------------------------
There has been no production from Havieron.
------------------------------------------------------------------------------------------------
Gold and copper are the only revenue generating products
assumed to be recovered. There is sufficient metallurgical
testwork to support these assumptions for the South East
Crescent, Link Zone and Havieron Breccia domains. The
resource does not include any by-products.
------------------------------------------------------------------------------------------------
A parent block size of 20x20x20m (East, North, RL) with
sub-blocks down to 4x4x4m has been used for all mineralised
domains. This is geostatistically acceptable for the South
East Crescent Zone, where the data density ranges from
50-100m However, this size is considered small for the
Breccia Zones, even though parent-cell estimation was
used for such. Resources in this domain have been reported
using NSR-based shells that mitigate most of the detrimental
effects of the block size.
------------------------------------------------------------------------------------------------
The South East Crescent Zone is almost exclusively estimated
to be above the cut-off grade and minimum stoping thickness
(around 5m). Planned stope heights are well above the
block vertical dimension (20m). Change-of-support tests
over various block dimensions also suggest that selectivity
issues are unlikely to be material for this domain. The
Breccia Zones are mainly low grade and the model for such
is not designed for assessing selective mining options.
Change-of-support tests revealed significant differences
between modelled and theoretical tonnages and grades at
cut-offs well above the reporting cut-off (A$50 NSR/t).
------------------------------------------------------------------------------------------------
Domains have principally been defined on gold grade, with
copper, iron and sulphur grades also having a significant
impact. Bismuth tends to be well, albeit variably, correlated
with gold and so the gold domains are considered appropriate
for estimating bismuth. In addition, in the upper parts
of the deposit a Bismuth domain has been developed within
the South East Crescent to improve the estimate in these
areas. While copper is less well correlated to gold, the
gold domains are considered appropriate for estimating
copper. Within these domains all grades (gold, copper,
bismuth, iron, sulphur, nickel, cobalt, calcium and magnesium)
have been estimated independently. Given that each of
these elements is assayed for each sample co-estimation,
such as co-kriging, was deemed unnecessary.
------------------------------------------------------------------------------------------------
The geological interpretation controls the resource estimates
through the domaining, boundary controls between domains,
and unfolding trend modelling as previously described.
------------------------------------------------------------------------------------------------
The grade distributions for gold, copper and bismuth are
strongly skewed. In addition, the very high grade composites
cannot be sub-domained out with the existing density of
data. As such, outlier grades were cut as previously described.
------------------------------------------------------------------------------------------------
The estimated block grades and densities were compared
to the raw and composite grades and densities using swath
plots, cross-sections and statistical analysis.
------------------------------------------------------------------------------------------------
There is no reconciliation data for Havieron.
---------------- ------------------------------------------------------------------------------------------------
Moisture All tonnages are calculated and reported on a dry tonnes
basis.
---------------- ------------------------------------------------------------------------------------------------
Cut-off As Havieron is a multi-element deposit, a Net Smelter
parameters Return (NSR) cut-off is adopted. The generic NSR formula
is as follows:
---------------- ------------------------------------------------------------------------------------------------
NSR (AUD/t processed) = (Gold Price * Ore Gold Grade *
Gold Recovery * Gold Payability) + (Copper Price * Ore
Copper Grade * Copper Recovery * Copper Payability) -
(Treatment, Refining, Freight, Insurance and Selling Costs)
- Penalties - Royalties
---------------- ------------------------------------------------------------------------------------------------
The NSR calculation for Mineral Resources takes into account
revenue factors, metallurgical recovery assumptions, transport
costs, refining charges, penalties and royalty charges
at a gold price of US$1,700 per ounce, copper price of
US$3.75 per pound (US$8,265/t) and an USD:AUD exchange
rate of 0.72. Commodity prices and exchange rate forecasts
were based on combination of peer pricing analysis and
broker consensus forecast data.
------------------------------------------------------------------------------------------------
The nominal cut-off value for resource reporting depends
on the style and geometry of mineralisation with the South
East Crescent Zone being amenable to stoping, whereas
the Breccia Zones require a less selective (and lower
cost) mining method. The cut-offs were derived after incorporating
mining, haulage, processing and general and administration
costs.
------------------------------------------------------------------------------------------------
The marginal cut-off for SLOS ("sub-level open stoping",
for the South East Crescent Zone) is estimated at A$80
NSR/t, and accounts for mining, haulage, processing and
general and administration (G&A) costs, which are based
on the PFS Economic Evaluation average Life-of-Mine (LOM)
Costs.
------------------------------------------------------------------------------------------------
The Mineral Resource was defined based on a threshold
of A$80 NSR/t within the South East Crescent Zone. The
vast majority (>90%) of the estimated South East Crescent
Zone material reports above the A$80 NSR/t, as such domaining
all material below this cut-off is not practicable. Areas
of South East Crescent Zone material that had a higher
frequency of blocks below A$80 NSR/t were removed from
the classification and grouped with the adjacent Breccia
domains.
------------------------------------------------------------------------------------------------
The cut-off for the Breccia Zones (assuming SLC or "sub
level caving") is estimated at A$50 NSR/t, and accounts
for mining, haulage, processing and G&A costs, which are
based on the PFS analysis.
------------------------------------------------------------------------------------------------
For the Breccia Mineral Resources, a smoothed shell was
generated in Leapfrog(tm) Version 2023.1 based on a threshold
of A$50 NSR/t and includes internal below value cut-off
blocks and excludes isolated above cut-off blocks. As
the Breccia Resources are consider non-selective bulk
mining domains all sub-economic material within the final
A$50 NSR/t shell was classified to represent the non-selective
nature.
------------------------------------------------------------------------------------------------
Both the South East Crescent Mineral Resources and Breccia
Mineral Resources represent the limit of reasonable prospects
of eventual economic extraction. The A$80 NSR/t cut-off
for South East Crescent Mineral Resources and A$50 NSR/t
cut-off for Breccia Mineral Resources are based on the
current understanding of the Havieron deposit and other
benchmarked operations.
------------------------------------------------------------------------------------------------
Greatland used smoothed NSR shells to define its Breccia
Resources and this results in some material below the
nominal cut-off being included in the resources. The following
table shows the total and proportion of the Mineral Resource
tonnages and Contained Metal above and below the nominal
cut-off NSR each Domain/Lode/category combination. A key
observation is the NSR indicator shells process in Leapfrog(tm)
brings in additional lower NSR material to encapsulate
higher grade material if the outcome is warranted, in
a sense building in some degree of expected dilution for
that material. Zone Category Cut Tonnage Tonnage Metal Metal
Off ($NSR) Above Below Above Below
Crescent Indicated $80 91% 9% 98% 2%
----------- ------------ -------- -------- ------- -------
Inferred $80 84% 16% 94% 6%
---------------------- ------------ -------- -------- ------- -------
Link
Zone Indicated $80 96% 4% 99% 1%
---------- ----------- ------------ -------- -------- ------- -------
Inferred $80 71% 29% 83% 17%
---------------------- ------------ -------- -------- ------- -------
Breccia Indicated $50 78% 22% 92% 8%
========== -------- -------
Inferred $50 63% 37% 85% 15%
====================== ============ ======== ======== ======= =======
Total 74% 26% 92% 8%
------------ -------- -------- ------- -------
---------------- ------------------------------------------------------------------------------------------------
Mining factors The PFS showed that the South East Crescent Zone and immediately
or assumptions adjacent diluent material is amenable to mining by sub-level
open stoping (SLOS) with minimum mining dimensions of
5mW x 15mL x 25mH. The updated resource model supports
that finding.
---------------- ------------------------------------------------------------------------------------------------
The PFS suggests that the Breccia Zones may be amenable
to, and require the lower costs of, bulk mining methods
such as sub-level caving (SLC). SLC is likely to require
minimum mining dimensions of 80mW x 100mL x 100mH. The
Mineral Resources assume there will be no significant
permanent pillars in the resource volume, although it
is possible that a pillar will need to be left between
the paste-filled South East Crescent Zone stopes and the
Breccias, and which will be accounted for during Ore Reserve
estimation.
---------------- ------------------------------------------------------------------------------------------------
Metallurgical It is anticipated that Havieron ore will be processed
factors on a campaign basis through the Telfer Treatment Plant
or assumptions circuit at a throughput of approximately 3 Mtpa. It is
anticipated that metal will be recovered through conventional
flotation to produce a copper/gold concentrate and a gold
doré through a newly installed flotation tails carbon-in-leach
(CIL) circuit. The technology associated with the ore
processing is conventional and the flowsheet is similar
to that utilised by other operations.
---------------- ------------------------------------------------------------------------------------------------
Metallurgical recovery assumptions are based on detailed
analysis and laboratory flotation and leach test work
completed on 47 geo-metallurgical variability samples
during the Havieron Concept Study (2020) and Stage 1 PFS
(2021) with good spatial coverage of the South East Crescent
Zone Domain. Another 38 geo-metallurgical variability
samples have been tested during the Feasibility Study
increasing the special coverage. Of the 87 samples, 29
samples are located in the Breccia Zones, 56 samples are
located in the South East Crescent Zone Domain. Based
on these samples, metallurgical recoveries for gold are
anticipated to average approximately 87% and recoveries
of copper are expected to average approximately 87% throughout
the life of the project. Note that Greatland does not
have any metallurgical testwork results for the Eastern
Breccias and it is assumed that they have similar metallurgical
properties to their corresponding Breccias.
---------------- ------------------------------------------------------------------------------------------------
Environmental Detailed environmental studies have been undertaken in
factors the Project area and include flora and vegetation, fauna,
or assumptions subterranean fauna, waste rock characterisation, soil
and landform study, surface hydrology assessment, a basic
hydrogeological assessment and a greenhouse gas emissions
study.
---------------- ------------------------------------------------------------------------------------------------
The Project has been designed to recognise biodiversity
values and, through consultation with Martu and their
native title corporation (JYAC), minimise the impacts
to sites and landscapes of cultural significance. The
footprint for the Project has been minimised through the
use of existing tracks and areas of disturbance, as well
as utilising the existing Telfer mine infrastructure to
process the ore and dispose of the tailings material.
---------------- ------------------------------------------------------------------------------------------------
Waste rock characterisation has been undertaken and shows
that it contains material which has potentially acid forming
(PAF) and metalliferous drainage, in addition to dispersive
or saline material. The portion of PAF material is less
than 1% of total waste volumes. Waste dumps have been
designed for the life of mine that have incorporated cells
to safely encapsulate the PAF material. The waste dump
is to be located near the boxcut to minimise haulage distance
and considering the local surface terrain and environmental
and cultural aspects.
------------------------------------------------------------------------------------------------
A staged approach for approvals is being undertaken, with
Stage 1 currently approved, which has allowed the development
of the boxcut, decline and service corridor. These approvals
also allow for a waste rock dump, evaporation ponds and
supporting infrastructure such as offices and workshops.
------------------------------------------------------------------------------------------------
Stage 2 approvals are expected to consist of a SLOS underground
mine, permanent infrastructure corridor, associated infrastructure
and changes to Telfer mine approvals to accept Havieron
tailings in existing tailings storage facilities.
---------------- ------------------------------------------------------------------------------------------------
Bulk Density Havieron has an extensive database of bulk density measurements
based on the Archimedes method (water immersion) of 10-20cm
samples taken at 10-50m intervals down the hole. Whilst
the geology, and thus density, can change rapidly down
the hole, the number of measurements means that the data
set is likely to be representative for the purposes of
this estimate.
---------------- ------------------------------------------------------------------------------------------------
Most of the core in the mineralised zones is very competent
and of low to negligible porosity.
---------------- ------------------------------------------------------------------------------------------------
Bulk density is estimated into blocks using OK on a domain-specific
basis. The variability of density is relatively low in
the Breccia zones and the scope for an estimation related
bias is very low, even at the local scale. The variability
of density in the South East Crescent zone is higher and,
whilst local estimation-related biases may occur, it is
unlikely that a significant global bias exists.
---------------- ------------------------------------------------------------------------------------------------
Classification Resources preliminarily classified on the basis of the
quality and quantity of data, the geological and grade
continuity, and the confidence in the gold grade estimates.
Data quality is implicitly accounted for by excluding
unreliable data from the estimate.
---------------- ------------------------------------------------------------------------------------------------
Confidence in the estimate was initially assessed using
the 'Slope-of-regression', 'Average Distance to informing
composites', 'Closest Distance to informing composites',
'Kriging Efficiency', 'Number of Informing Drill Holes',
and 'Number of Informing Composites' statistics stored
during estimation. The schema was then simplified to only
account for the 'Slope-of-regression' and 'Average Distance
for informing composites' statistics. Shells based on
these two statistics were computed at various thresholds
for each of the domains. The chosen nominal parameters
were:
---------------- ------------------------------------------------------------------------------------------------
Domain Category Slope Average Distance
-------------------- ---------------------- ------------ ------------------------------------
CRS Indicated >0.6 <45m
-------------------- ---------------------- ------------ ------------------------------------
CRS Inferred >0.3 <75m
-------------------- ---------------------- ------------ ------------------------------------
Breccias Indicated >0.6 <30m
-------------------- ---------------------- ------------ ------------------------------------
Breccias Inferred >0.3 <75m
-------------------- ---------------------- ------------ ------------------------------------
This approach led to some blocks not meeting these criteria
to be included and some meeting these criteria to be excluded
from the shells. Furthermore, some edges were manually
trimmed to ensure continuity of classification.
------------------------------------------------------------------------------------------------
The final classification then considered the 'reasonable
prospects of eventual economic extraction', and specifically
the mineability by the proposed method, the recoverability
by the proposed processing method, and the likelihood
that the resource would be above the cut-off.
------------------------------------------------------------------------------------------------
Several early drill holes were deemed to be of low reliability
and were excluded from the estimation. All remaining data
are considered suitable for the purposes of resource estimation.
------------------------------------------------------------------------------------------------
Geological and grade continuity in the South East Crescent
Zone can reasonably be assumed in most places, and implied
elsewhere. When combined with the density and orientation
of data, as well as the likelihood and impact of any misestimation,
this supports the assigned Indicated (assumed) and Inferred
(implied) resources classification.
------------------------------------------------------------------------------------------------
Geological and grade continuity in the Breccia zones is
typically much lower. However, the data density is moderate-high
in the southern parts of the Breccias adjacent to the
South East Crescent Zone and geological and grade continuity
can be reasonably assumed. As such, some of this material
has been assigned as Indicated resources. The remainder
of the Breccia Zone has been assigned as Inferred resources
as the continuity of geology and grade can only be implied
from the available data. The confidence in the estimates
of the Breccia zones decreases rapidly as the cut-off
is increased and significant misrepresentation of tonnages,
grades and location above elevated cut-offs in this model
is likely, and so the classification is strictly only
applicable at the reporting cut-off A$50 NSR/t.
------------------------------------------------------------------------------------------------
The classification appropriately reflects the views of
the Competent Person.
---------------- ------------------------------------------------------------------------------------------------
Audits or SRK Consulting (Australasia) Pty Ltd has completed an
reviews independent technical assessment of the 2023 Mineral Resource
estimates completed by Greatland for the Havieron gold
and copper deposit. As part of that assessment, SRK reviewed
the resource modelling methods and parameters and is of
the opinion that they are reasonable and take into consideration
all of the current exploration data and levels of technical
knowledge of the Havieron deposit. SRK considers that
the Mineral Resources have been reported in accordance
with guidelines and principles outlined in the 2012 edition
of the Australasian Code for the Reporting of Exploration
Results, Mineral Resources and Ore Reserves (the JORC
Code, 2012 edition).
---------------- ------------------------------------------------------------------------------------------------
Discussion Greatland has conducted Change-of-Support studies using
of relative the Discrete Gaussian Method for the South East Crescent
accuracy Zone and Breccia Zones. These studies revealed that the
/ confidence estimates for the South East Crescent Zone are robust
within the context of the likely operating cut-off value.
The studies also revealed that the estimates for the Breccia
Zones are reasonable at the likely operating cut-off (A$50
NSR/t), but this accuracy rapidly diminishes as the cut-off
is increased.
------------------------------------------------------------------------------------------------
There is no historical production from Havieron.
------------------------------------------------------------------------------------------------
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END
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