TIDMGGP
RNS Number : 5140D
Greatland Gold PLC
03 March 2022
--
3 March 2022
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
( " Greatland " or "the Company " )
Updated Mineral Resource substantially increases Havieron
Resource and Reserve
Mineral Resources (including Ore Reserves) increase to 5.5M oz
Au and 218kt Cu or 6.5M oz AuEq(1) ,
an increase of 2.1M oz AuEq(1) since the last Mineral Resource
update
Probable Ore Reserves now stand at 2.4M oz Au and 109kt Cu or
2.9M oz AuEq(1) ,
compared to the 1.7M oz AuEq(1) in the Initial Ore Reserve
estimation
Initial Mineral Resource estimated in the Eastern Breccia
Updated Mineral Resource incorporates an additional 10 months of
consistently impressive drilling results since the February 2021
drilling cut-off used for the last Mineral Resource update
Havieron Mineral Resource Update Highlights*
-- A 53% increase in total gold content to 5.5M oz Au (6.5M oz
AuEq (1) )
-- A 63% increase in Indicated Mineral Resource gold ounces to
3.1M oz Au
-- An Initial Inferred Mineral Resource estimated at the Eastern
Breccia
-- Mineral Resources include 33Mt @ 3.28 g/t Au and 0.48% Cu
(containing 3.5M oz Au and 158kt Cu or 4.2M oz AuEq (1) ) in the
South East Crescent Zone
-- Update has been subject to a detailed analysis and review,
independently assessed by SRK Consulting and are reported in
compliance with JORC (2012) guidelines
Updated Mineral Resource estimate for the Havieron Deposit
(100%)(#)
Classification Tonnage Grade Metal Content AuEq (1)
Metal
Mt Au (g/t) Cu (%) Au (M Cu (kt) AuEq
oz) (M oz)
-------- --------- ------- ------ -------- ---------
Indicated 35 2.8 0.42 3.1 146 3.8
-------- --------- ------- ------ -------- ---------
Inferred 57 1.3 0.13 2.4 72 2.7
-------- --------- ------- ------ -------- ---------
Total Mineral Resource 92 1.9 0.24 5.5 218 6.5
-------- --------- ------- ------ -------- ---------
(#) Results are reported to one (gold) and two (copper)
significant figures to reflect appropriate precision in the
estimate, and this may cause some apparent discrepancies in totals.
Results represent 100% of the Mineral Resource for Havieron.
Mineral Resources in the Crescent are reported within a A$80 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 Estimates assume selective mining
of the South East Crescent Zone and bulk extraction in the Breccias
and are reported inside A$80 or A$50 Net Smelter Return/t(2)
("NSR/t") shells respectively.
Havieron Ore Reserve Update Highlights
-- 50% increase in contained gold ounces to 2.4M oz Au (2.9M oz
AuEq), including an 86%(3) conversion of Indicated Mineral
Resources to Probable Ore Reserves
-- The conversion rate of the South East Crescent Zone
reiterates the robust nature of the South East Crescent Zone within
the Havieron deposit while providing confidence in the ongoing
conversion of further South East Crescent Zone material as drilling
continues
-- Update has been subject to a detailed analysis and review,
independently assessed by SRK Consulting and are reported in
compliance with JORC (2012) guidelines
Updated Ore Reserve estimate tabulation for the Havieron Deposit
(100%)^
Tonnage Grade Metal Content AuEq (1)
Metal
Mt Au (g/t) Cu (%) Au (M Cu (kt) AuEq (M
oz) oz)
-------- --------- ------- ------ -------- ---------
Proved - - - - - -
-------- --------- ------- ------ -------- ---------
Probable 25 3.0 0.44 2.4 109 2.9
-------- --------- ------- ------ -------- ---------
Total Ore Reserve 25 3.0 0.44 2.4 109 2.9
-------- --------- ------- ------ -------- ---------
^ Data is reported to one (gold) or two (copper) significant
figures to reflect appropriate precision in the estimate and this
may cause some apparent discrepancies in totals. Data represents
100% of the Ore Reserve for Havieron. Ore Reserves are reported
above a cut-off of A$95 NSR/t and reported within mining shapes
based on a sub-level open stoping mining method. All reported metal
was derived from the South East Crescent Zone only.
Greatland Gold plc (AIM:GGP), a leading mining development and
exploration company with a focus on precious and base metals, is
pleased to provide an independently assessed update on the Mineral
Resources and Ore Reserves at the Havieron gold-copper deposit in
the Paterson region of Western Australia. The update is based on
increased drill density throughout the deposit with a further 87
drill holes for 59,270m completed since the last Resources and
Reserves update published in the Pre-Feasibility Study ("Stage 1
PFS"), which used drill data up to February 2021.
Havieron Growth
-- This Resource update is at a 'point in time', with a 2
December 2021 cut-off for drilling information used to inform the
Mineral Resource Estimate
-- Drilling is ongoing, with extension drilling targeting the
South East Crescent Zone at depth, while growth drilling targeting
the Eastern Breccia is underway with initial high grade
intersections, evidenced by HAD104(6) being comparable to those
seen at the South East Crescent Zone, demonstrating a promising
start
-- Drilling is also underway to continue to assess the broader
Havieron breccia system's suitability for a bulk mining
approach
-- Concurrent studies underway to assess production rates
greater than 3 million tonnes per annum ("Mtpa")
-- Targeting a further 40,000m of growth drilling in the year to
30 June 2022 which has the potential to further expand the Havieron
resource
Shaun Day, Chief Executive Officer of Greatland Gold plc,
commented: "This Mineral Resource and Ore Reserve update represents
a considerable increase on that which was defined in the Stage 1
PFS. The update has unearthed further aspects of the Havieron
system and validates that Havieron is a world class deposit with
significant growth potential. Through an independently verified
analysis, the total Mineral Resource at Havieron has increased to
6.5M oz of gold equivalent, an increase of almost 50% in 10 months
of drilling.
The exceptional 86% rate of conversion of Mineral Resources to
Ore Reserves demonstrates the quality of the high grade South East
Crescent Zone at Havieron.
The South East Crescent Zone Mineral Resource is now defined to
around 1,000m vertical extent below the Permian and still open at
depth. In addition, high grade intercepts are delineated below this
level, which further supports the potential for future Mineral
Resource and Ore Reserve growth.
In addition to the Mineral Resources within the Havieron Breccia
complex, growth drilling has now defined an initial Mineral
Resource within the separate Eastern Breccia complex. This is the
first Mineral Resource in a mineralised system outside the Havieron
Breccia system and remains open at depth and to the south. This
Eastern Breccia Mineral Resource does not capture the recent high
grade intercepts to its south, which is of similar grade to the
South East Crescent Zone.
With an ongoing and substantial expansion drilling campaign
continuing, there is every opportunity to deliver more growth to
the Mineral Resource and Ore Reserve as we continue to better
understand the extent of mineralisation across the broader Havieron
zonation.
The investment proposition for Greatland remains compelling,
with this further understanding of the quality and scale of
Havieron supported by this new Mineral Resource update. With
Havieron in a Tier One mining jurisdiction, under development with
a major partner in Newcrest, located near existing infrastructure
and a study indicating modest capex and low operating cost, this
confluence of factors position Havieron as a tremendous and
globally unique asset."
Company's updated Mineral Resource and Ore Reserve estimate
Mineral Resource and Ore Reserve 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,
future capital and operating costs and development timeline) 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 and Ore Reserve 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 or that any Ore Reserves will be
mined or processed economically.
This announcement and the updated Mineral Resource and updated
Ore Reserve estimates for the Havieron Project contained in it have
been prepared solely by Greatland based on relevant available
information and has not been reviewed by Newcrest Mining Limited
("Newcrest"). A subsidiary of Newcrest is the manager of the
Havieron Joint Venture and holds the majority participating
interest in that joint venture (currently 60% with an entitlement
(subject to the terms of the Joint Venture Agreement) to an
additional 10% interest and an option to acquire a further 5%
interest at fair market value). Whilst the information in this
announcement pertaining to the estimation and reporting of Mineral
Resources and Ore Reserves has been reviewed and approved by
relevant Competent Persons (4) and the updated Mineral Resource and
updated Ore Reserve estimates have been independently assessed by
SRK Consulting (Australasia) Pty Ltd5, the Company considers that
it is possible that: (i) in preparing any future resource and
reserve estimates for the Havieron Project, Newcrest may adopt
different interpretations, assumptions, parameters or plans, or
make different judgements, to those used or made by Greatland in
the updated Mineral Resource and Updated Ore Reserve estimates
contained in this announcement and (ii) the Havieron Joint Venture
may choose to carry out its operations (including the development
of the Havieron Project) in a manner different to the assumptions
used in the updated Mineral Resource and updated Ore Reserve
estimates 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. Readers are
cautioned not to place undue reliance on forward looking
statements, particularly in the current economic climate with the
significant volatility, uncertainty and disruption caused by the
COVID-19 pandemic. 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.
(1) The gold equivalent (AuEq) is based on assumed prices of
US$1,450/oz Au and US$3.23/lb Cu for Ore Reserve and assumed prices
of US$1,600/oz Au and US$3.50/lb Cu for Mineral Resource and
metallurgical recoveries based on block metal grade, reporting
approximately at 88% for Au and 84% for Cu which in both cases
equates to a formula of approximately AuEq = Au (g/t) + 1.5 * 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 metals
prices of US$1,600/oz Au and US$3.50/lb Cu, metallurgical
recoveries based on block metal grade reporting approximately at
88% for Au and 84% for Cu, an USD:AUD exchange rate of 0.73, as
well as treatment and refining costs, payables and royalties,
similar to those in the Stage 1 PFS.
(3) The Mineral Resource Conversion rate is based on the
conversion of contained metal within the Indicated Mineral Resource
to contained metal within the Ore Reserves, this calculates to
86%.
(4) See Competent Persons Statement below for details.
(5) See Sections 3 and 4 of Appendix 1 below for details.
(6) Refer to announcement "Havieron Exploration Update" dated
the 28 January 2022.
Enquiries:
Greatland Gold PLC +44 (0)20 3709 4900
Shaun Day info@greatlandgold.com
www.greatlandgold.com
SPARK Advisory Partners Limited (Nominated
Adviser)
Andrew Emmott/James Keeshan +44 (0)20 3368 3550
Berenberg (Joint Corporate Broker and Financial
Adviser)
Matthew Armitt/ Varun Talwar/ Detlir Elezi +44 (0)20 3207 7800
Canaccord Genuity (Joint Corporate Broker and
Financial Adviser)
James Asensio/Patrick Dolaghan +44 (0)20 7523 8000
Hannam & Partners (Joint Corporate Broker and
Financial Adviser)
Andrew Chubb/Matt Hasson/Jay Ashfield +44 (0)20 7907 8500
SI Capital Limited (Joint Broker)
Nick Emerson/Alan Gunn +44 (0)14 8341 3500
Luther Pendragon (Media and Investor Relations)
Harry Chathli/Alexis Gore +44 (0)20 7618 9100
Further Information on the Updated Mineral Resource and Updated
Ore Reserve at Havieron
Project Details
The Project containing the Havieron Au-Cu deposit is centred on
a deep magnetic anomaly 45km east of Telfer in the Paterson
Province on the traditional lands of the Martu people. The Project
is held in a joint venture between Greatland and Newcrest Mining
Limited ("Newcrest"), where Newcrest currently holds a 60% joint
venture interest and is entitled (subject to the terms of the Joint
Venture Agreement) to an additional 10% interest, giving an
aggregate interest of 70% (Greatland 30%).
Newcrest may also acquire an additional 5% joint venture
interest at fair market value (under the principles of the Joint
Venture Agreement) and, if exercised, Newcrest will be entitled to
an overall joint venture interest of 75% (Greatland 25%). As
detailed in the announcement of 21 December 2021, Newcrest has
issued a notice to Greatland informing it that Newcrest would like
to begin the process under the joint venture agreement to seek to
agree or, failing agreement, determine the option exercise price.
The Joint Venture commenced drilling during mid-2019 and has
completed 272 drill holes for 226,492m (at 28 January 2022), with
up to eight drill rigs in operation on the Project.
The Martu people and the Western Desert Land Aboriginal
Corporation (WDLAC) are key project stakeholders. The Martu hold
exclusive possession native title rights and interests over more
than 130,000 km(2) of land, including to all points around the
Telfer mine and Havieron Project. The Indigenous Land Use Agreement
(ILUA) with WDLAC, centred on the Telfer mine, extends to the
Havieron project.
The 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 associated
surface infrastructure, with these works formally commencing in
January 2021. The Stage 1 PFS released 12 October 2021 has outlined
the next stage of the Project which comprises a Feasibility Study
into the underground and surface development to establish the
initial mining area at Havieron and ore processing at Telfer.
The Stage 1 PFS assessed mining production methods including Sub
Level Open Stoping ("SLOS") with mining rates of 2 Mtpa to 3 Mtpa
and caving options up to 6 Mtpa. Surface infrastructure studies
were focused on the transportation of ore to the Telfer processing
plant with a range of options considered in early-stage evaluations
including conveyor, rail, pipeline and truck haulage, with the
latter adopted for the Ore Reserve estimate used in the Stage 1
PFS. Processing studies evaluated a modified Telfer process plant
to accommodate the Havieron ore.
The Stage 1 PFS demonstrated the potential to expand the Project
and increase the mining rate to 3 Mtpa or more based on the
upgrading of the October 2021 Inferred Mineral Resources and
additional potential Mineral Resource growth from immediately below
the South East Crescent Zone.
This release documents an update prepared solely by Greatland to
the Resources and Reserves documented in the Stage 1 PFS and has
not been reviewed by Newcrest. It is the preference of Greatland to
update the Project's Mineral Resource and Ore Reserve estimates in
line with Newcrest; however, in the context of Greatland's current
investigation of potential financing options, and other Project
decisions it may be required to make, it was considered necessary
for the Company to undertake its own analysis (the last Havieron
Mineral Resource and Ore Reserve update being released as part of
the Stage 1 PFS with a 5 February 2021 cut-off for drilling
information ).
Updated Mineral Resource Estimate
The updated Mineral Resource estimate for the Havieron Deposit
prepared by Greatland (Table One) ("Updated Mineral Resource") is
based on drilling completed to 2 December 2021, comprising 311
holes for 209,911m, inclusive of 87 holes for 59,270m which are
additional to the drilling data used in the Stage 1 PFS Mineral
Resource and Ore Reserve estimates released on 12 October 2021.
Table One: Updated Mineral Resource estimate tabulation for the
Havieron Deposit (100%)#:
Domain Classification Tonnage Grade Metal Content AuEq
(1) Metal
Mt Au (g/t) Cu (%) Au (M Cu (kt) AuEq
oz) (M oz)
---------------- -------- --------- ------- ------ -------- -----------
South East
Crescent Indicated 26 3.3 0.52 2.8 136 3.4
---------------- -------- --------- ------- ------ -------- -----------
Inferred 7 3.2 0.33 0.7 22 0.8
----------------------------------- -------- --------- ------- ------ -------- -----------
Northern Breccia Indicated 9 1.1 0.11 0.3 10 0.4
---------------- -------- --------- ------- ------ -------- -----------
Inferred 36 1.0 0.1 1.2 37 1.3
----------------------------------- -------- --------- ------- ------ -------- -----------
Eastern Breccia Indicated 0.0 0.0 0.0 0.0 0.0 0.0
---------------- -------- --------- ------- ------ -------- -----------
Inferred 14 1.2 0.09 0.5 13 0.6
----------------------------------- -------- --------- ------- ------ -------- -----------
Total Indicated 35 2.8 0.42 3.1 146 3.8
---------------- -------- --------- ------- ------ -------- -----------
Inferred 57 1.3 0.13 2.4 72 2.7
----------------------------------- -------- --------- ------- ------ -------- -----------
Indicated
Grand Total + Inferred 92 1.9 0.24 5.5 218 6.5
---------------- -------- --------- ------- ------ -------- -----------
(#) Results are reported to one (gold) and two (copper)
significant figures to reflect appropriate precision in the
estimate, and this may cause some apparent discrepancies in totals.
Results represent 100% of the Mineral Resource for Havieron.
Mineral Resources in the South East Crescent Zone are reported
within a A$80 NSR/t shell while Mineral Resources in the Breccias
are reported within a A$50 NSR/t shell.
The Updated Mineral Resource estimates are 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 more
information relating to data collection and resource
estimation.
The Updated Mineral Resource represents a significant increase
on the Mineral Resources defined in the Stage 1 PFS (which was
prepared at a 'point in time' using a 5 February 2021 cut-off for
drilling information) including:
-- A 75% increase in total (Indicated plus Inferred) tonnes;
-- A 53% increase in total gold content; and
-- A 63% increase in gold ounces in the Indicated category.
Material differences between the Updated Mineral Resource and
the previously announced Stage 1 PFS Mineral Resource are as
follows:
-- A further 38,088 metres of infill drilling completed in the
approximately 10 months since 5 February 2021 to 2 December 2021
within the South East Crescent Zone. This drilling validated both
geological and grade continuity of the Stage 1 PFS South East
Crescent Zone Mineral Resource, converting some Inferred Resource
to Indicated Resource;
-- Growth drilling (21,182 metres completed since 5 February
2021 to 2 December 2021) which returned further high-grade results
with the South East Crescent Zone now having a vertical extent of
over 1,000 metres and extending to over 200 metres below the
earlier Stage 1 PFS Mineral Resource;
-- The Updated Mineral Resource has been calculated using an
A$80 NSR/t value cut-off for the Crescent material, compared with a
A$100 NSR/t cut-off used in the Stage 1 PFS estimation. Due to the
high NSR value of the majority of the South East Crescent Zone
material this change is not considered to have resulted in a
material change in the resources;
-- While different commodity prices have been used (US$1,600/oz
Au and US$3.50/lb Cu and a USD:AUD exchange rate of 0.73 for the
Updated Resource estimate compared with US$1,400/oz Au and
US$3.40/lb Cu and a USD:AUD exchange rate of 0.75 used in the Stage
1 PFS), due to the high NSR value of most of the South East
Crescent Zone material this change is not considered to resulted in
a material change in the South East Crescent Zone Resources. The
increase in the Breccia Mineral Resources within the Havieron
Breccia are a result of additional drilling and some effect of the
commodity price variation between the models; and,
-- The Eastern Breccia Resource, which forms part of the Updated
Mineral Resource was not part of the previous Stage 1 PFS Mineral
Resource.
Based on d rilling to date the Havieron deposit comprises an
ovoid shaped body of variable brecciation, alteration and sulphide
mineralisation with dimensions of approximately 650m x 350m
trending in a north-west orientation, extending to over 1,100m in
depth below 420m of Permian cover.
Within this ovoid body a sulphide rich South East Crescent Zone
has been defined, it is 5-40m wide, extending over 700m in length
(when unfolded in plan just below the basement contact) and defined
over 1,000m vertically, tapering to 600m in length (unfolded) at
this depth and still open at depth. The South East Crescent Zone
has continued to be the focus of drilling and has been
progressively infilled to a nominal drill spacing of 50m for the
Indicated Mineral Resources, and 75m spacing for the Inferred
Mineral Resources.
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.
The Eastern Breccia complex comprises a second, separate body of
mineralisation located on the northeast margin of the ovoid body
developing around the 4000mRL (850m below the Permian
unconformity), but open at depth and along strike. The Eastern
Breccia comprises broad zones of actinolite cemented breccia hosted
in metasediment rocks, with more abundant vein quartz and less
calcite breccia than the main Havieron deposit breccias. The
Eastern Breccia Mineral Resource is drilled to a nominal 75m x 75m
spacing. Infill and extension drilling of the Eastern Breccia is
ongoing.
The Indicated Mineral Resource estimate includes material from
the South East Crescent Zone and adjacent Breccias only. The
Inferred Mineral Resource estimate is comprised of some South East
Crescent Zone, the adjacent Breccia Zones, a portion of the
Northern Breccia to an RL of 3950m (850m below the Permian
unconformity) and the Eastern Breccia where drill data provides
sufficient support to define an appropriate level of geological
control and statistical confidence .
Ordinary Kriging of 5m composites of gold and copper was
undertaken into 20m x 20m x 20m blocks and re-blocked into 4m x 4m
x 4m blocks where required. The Mineral Resource model was domained
utilising the geological units defining the South East Crescent
Zone, the Cemented Breccia and Crackle Breccia. Hard boundaries
were used between the Crescent Zone and the Breccia Zones and a
transitional boundary of around 20m was used between the Breccia
Zones. Kriging Neighbourhood Analysis was used to define the search
neighbourhood for gold. Gold, copper and bismuth were estimated
independently of each other. Composite copper, gold and bismuth
grades were capped prior to estimation. Within the Havieron Breccia
complex the resource estimation is based entirely on interpolation
while the Eastern Breccia complex, which is considered a separate
system, is based on 70% interpolated and 30% extrapolated blocks
(which is defined as the nearest informing composite being more
than 30m away and estimated by data from fewer than 4 drillholes)
representing the early stage of resource definition in this area.
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 average
weighted distance and slope of regression statistics for estimated
gold grades. The Indicated Mineral Resource classification within
the South East Crescent 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 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 metals prices of US$1,600/oz Au and US$3.50/lb Cu,
metallurgical recoveries based on block metal grade, reporting
approximately at 88% for Au and 84% for Cu, an USD:AUD exchange
rate of 0.73, as well as treatment and refining costs, payables and
royalties, similar to those used in the Stage 1 PFS .
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.
Updated Ore Reserve Estimate
The updated Havieron Ore Reserve estimate prepared by Greatland
("Updated Ore Reserve") is reported as a Probable Ore Reserve in
accordance with the 2012 edition of the Australasian Code for
Reporting of Exploration Results, Mineral Resources and Ore
Reserves (the JORC Code). For more details regarding the Ore
Reserve estimation process, refer to Appendix 1 (JORC Table 1 -
Sections 4) . The Updated Ore Reserve contains 25 Mt at 3.0 g/t Au
and 0.44% Cu for 2.4M oz of gold and 109 kt of copper (Table
Two).
Table Two: Updated Ore Reserve estimate tabulation for the
Havieron Deposit (100%)(^) :
Tonnage Grade Metal Content AuEq (1)
Metal
Mt Au (g/t) Cu (%) Au (M Cu (kt) AuEq (M
oz) oz)
-------- --------- ------- ------ -------- ---------
Proved - - - - - -
-------- --------- ------- ------ -------- ---------
Probable 25 3.0 0.44 2.4 109 2.9
-------- --------- ------- ------ -------- ---------
Total Ore Reserve 25 3.0 0.44 2.4 109 2.9
-------- --------- ------- ------ -------- ---------
(^) Data is reported to one (gold) or two (copper) significant
figures to reflect appropriate precision in the estimate and this
may cause some apparent discrepancies in totals. Data represents
100% of the Ore Reserve for Havieron. Ore Reserves are reported
above a cut-off of A$95 NSR/t and reported within mining shapes
based on a sub-level open stoping mining method. All reported metal
was derived from the South East Crescent Zone only.
This is a significant increase to the Ore Reserves contained in
the Stage 1 PFS (prepared at a 'point in time' using a 5 February
2021 cut-off for drilling information), including:
-- A 50% increase in total gold content;
-- A 84% increase in Reserve tonnes; and,
-- A 86% conversion of Au Metal within the South East Crescent
Zone Indicated Resource to Probable Reserve.
Material differences between the Updated Ore Reserve and the
previously announced Stage 1 PFS Ore Reserve are as follows:
-- The increased drilling completed in the period 5 February
2021 to 2 December 2021, both infilling and extending the Indicated
Mineral Resources defined in the South East Crescent Zone and
adjacent Breccias;
-- The Updated Ore Reserve has been calculated using a break
even cut off value of approximately A$95/t milled, and a marginal
cut off value of approximately A$80/t milled, compared to a A$130
NSR/t cut-off used in the Stage 1 PFS Ore Reserve. The reduced
cut-off was calculated from first principles and the reduction is
primarily as a result of increased throughput from 2 Mtpa to 3
Mtpa, the latter being in line with the Stage 1 PFS Investment Case
carried forward into the Feasibility Study as part of the Forward
Works Program; and
-- Metal price changes from U$1,300/oz to U$1,450/oz for gold,
U$3.0/lb to U$3.23/lb for copper and exchange rate from 0.75 to
0.73 USD per AUD. These changes had a non-material impact on the
overall Ore Reserve as the majority of the South East Crescent Zone
material are well above cut-off value at both price points. Lower
grade material is more sensitive to price assumptions but makes up
a non-material portion of the Ore Reserve.
The Updated Ore Reserve is based on a SLOS mining method with
paste fill and truck ore haulage at a 3 Mtpa mining rate .
Metallurgical test-work has been executed on samples taken from the
Havieron deposit during the Stage 1 PFS and in preceding studies.
The test-work undertaken is of an adequate level to ensure an
appropriate representation of metallurgical characterisation and
the derivation of corresponding metallurgical recovery factors.
The Havieron site does not currently have infrastructure to
support mining operations. Major infrastructure requirements are
included in the Stage 1 PFS capital cost estimates, which are based
on multiple market prices across all technical disciplines.
Provision has been made for capital expenditure requirements for
new equipment, infrastructure and replacement of infrastructure and
equipment during the life of the mine is based on the Stage 1 PFS.
A contingency has been factored into the capital cost estimate
consistent with the level of accuracy of the Stage 1 PFS.
The Updated Ore Reserve is based on the Stage 1 PFS cost
estimates. The Stage 1 PFS cost estimates have been built up from a
combination of existing Telfer site costs scaled for the Havieron
material throughput rate, first principles cost modelling and
quotations where practicable.
The Probable Ore Reserve is based on Indicated Mineral Resources
and diluting material only. Metal for Inferred Mineral Resource
material was not considered for the Updated Ore Reserve and did not
contribute to the mine design or economic evaluation. No Measured
Mineral Resources are stated for this deposit and therefore no
Proved Ore Reserves were estimated.
The Updated Ore Reserve has been prepared in line with the
following bases used in the Stage 1 PFS:
-- decline, accesses to the levels, ore passes, ventilation
raises and other underground excavations;
-- Sub-level open stoping (SLOS) stopes with paste fill;
-- paste fill plant and underground distribution system;
-- ventilation shafts, fans, regulators and refrigeration
equipment;
-- dewatering, electrical and other service equipment; and
-- truck haulage of ore to surface via the access decline.
The following Modifying Factors have been applied to all
production shapes to accurately represent the expected mined tonnes
and grades :
-- dilution factors for unplanned overbreak in primary,
secondary and tertiary stopes (average 9%) consisting of waste
(average 6%) and stope paste (average 3%);
-- dilution included at zero grade; and
-- mining recovery factor of 97.5%.
The Updated Ore Reserve includes approximately 2.4 Mt of
Inferred Mineral Resource as dilution. The metal contained in this
material was not considered and did not contribute to the economic
assessment or metal reported in the Updated Ore Reserve.
Havieron ore is anticipated to be processed on a campaign basis
through the existing Telfer Train 2 Treatment Plant circuit
(consistent with the Stage 1 PFS ) and at a throughput of
approximately 3 Mtpa. Metal recovery is expected to be through
conventional flotation to produce a copper/gold concentrate and
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
38 variability samples during the Havieron Concept Study (2020) and
Stage 1 PFS (2021) with good spatial coverage of the South East
Crescent Zone. Of the 38 samples, 8 samples are located in the
Breccia Zones and 30 samples are located in the South East Crescent
Zone, of which 21 samples are located within the Stage 1 PFS South
East Crescent Zone Indicated Mineral Resources. Based on these
samples metallurgical recoveries for gold are anticipated to
average approximately 88% and recoveries of copper are expected to
average approximately 84% throughout the life of the project.
Bismuth is the key deleterious element for the gold/copper
concentrate product with potential smelter penalties incurred on
the basis of bismuth content above a threshold level. The impact of
bismuth in concentrate is anticipated to be managed by mine
sequencing and concentrate blending.
The Updated Ore Reserve employs a value-based cut-off determined
from the NSR value equal to the site operating cost included within
the Stage 1 PFS. The NSR calculation takes into account revenue
factors, metallurgical recovery assumptions, transport costs,
refining charges, and royalty charges.
The NSR uses metals prices of US$1,450/oz Au and US$3.23/lb Cu,
metallurgical recoveries based on block metal grade, reporting
approximately at 88% for Au and 84% for Cu, an USD:AUD exchange
rate of 0.73, as well as treatment and refining costs, payables and
royalties, similar to those used in the Stage 1 PFS.
Detailed environmental studies have been undertaken in the
Havieron project area and include flora and vegetation, fauna,
subterranean fauna, waste rock characterisation, soil and landform
study, surface hydrology assessment, a basic hydrogeological
assessment and a greenhouse gas emissions study.
The Havieron project has been designed to recognise biodiversity
values and, through consultation with Martu and their native title
corporation (WDLAC), 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 Gold 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.
The site operating costs include mining cost, processing cost,
relevant site general and administration costs and relevant
sustaining capital costs. These costs equate to a break even cut
off value of approximately A$95/t milled, and a marginal cut off
value of approximately A$80/t milled.
Estimation of the Updated Ore Reserve involved standard steps of
mine optimisation, mine design, production scheduling and financial
modelling. Factors and assumptions have been based on benchmarked
performance from similar SLOS operations. The Updated Ore Reserve
has been evaluated through a financial model. All operating and
capital costs as well as Ore Reserve revenue factors stated in this
document were included in the financial model. A discount factor of
4.5% real was applied. This process demonstrated that the Updated
Ore Reserve has a positive NPV. Sensitivities were conducted on the
key input parameters including commodity prices, capital and
operating costs, ore grade, mined tonnes, exchange rate and
metallurgical recoveries confirming the estimate to be robust.
Newcrest stated on 17 February 2022 as part of their Half Year
Results Update that the decline experienced difficulty in poor
ground conditions during the early stages. The team is working to
understand the impact on the development schedule and this may also
impact on vertical development. First production ore is expected in
FY24 (rather than H1 FY24) and more updates will be provided as
information comes to hand.
Approvals
A mining lease has been granted over the orebody and a
miscellaneous licence granted along the existing service
corridor.
A staged approach for approvals is being undertaken with Stage 1
currently approved which has allowed the development of the box
cut, 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 approvals to accept Havieron tailings in
existing tailings storage facilities. The approvals for Stage 2
consist of both Commonwealth and State level approvals with
engagement well advanced with all regulatory bodies. The approval
timelines outlined in the Stage 1 PFS are considered
achievable.
For Stage 2 approvals an application is expected to be made for
an additional miscellaneous licence to secure access for an
infrastructure corridor to connect Telfer and Havieron (including
haul road, powerlines and water pipes). This is not considered a
risk to the timelines or project.
Indicative Production Profile (100% terms)
The Updated Ore Reserve is based on the updated Indicated
Mineral Resource estimate and approximately 3 Mtpa underground SLOS
operation with an expected mine life of 10 years. Ore is proposed
to be transported in trucks along a new 55km long haul road to the
modified processing plant at the Telfer mine and tailings deposited
at Telfer's existing tailings storage facility (TSF).
Multiple stope priority runs were conducted to determine the
optimal sequence which maximised the number of years at peak
production while reducing and compressing the production tail as
much as practical. The production rate of 3 Mtpa for the Havieron
SLOS was determined by maximising the steady state production of
the sequence.
Table Three : Indicative Updated Ore Reserve Production
Profile*:
Year Plant Feed Average Gold Average Copper
(Mt) Grade Grade
(g/t Au contained) (% Cu contained)
FY24 0.70 3.26 0.69
FY25 2.16 3.03 0.67
FY26 2.69 3.10 0.47
FY27 2.83 2.78 0.46
FY28 2.90 2.52 0.39
FY29 2.74 2.78 0.37
FY30 2.74 3.21 0.37
FY31 3.03 3.28 0.42
FY32 2.92 3.17 0.35
FY33 1.76 2.82 0.37
FY34 0.47 3.25 0.49
Total 24.92 2.98 0.44
(*) Data is rounded to two decimal places, which may cause some
apparent discrepancies in totals. Data represents 100% of the Ore
Reserve for Havieron.
Mine Development and Sequence
Sub-Level Open Stoping (SLOS) is a large-scale open stoping
method that is conducted over multiple levels at once. Once the
stope has been mined out it is backfilled with paste to maintain
the overall stability of the opening and enable mining of adjacent
stopes. This method is typically applied to strong orebodies that
require minimal support and are surrounded by competent country
rock, such as the Havieron deposit. Stopes are mined in a
checkerboard fashion with primary stopes mined first, followed by
the intermediate secondary stopes. The mining sequence is globally
top down, divided into a number of different vertical fronts,
separated by temporary horizontal sill levels which are recovered
after the levels immediately above and below have been mined and
filled.
A sub-level spacing of 50m with temporary sill levels located
20m below a mining front were selected. Some sub-level spacings are
increased by up to 10m to accommodate the inclusion of ore,
minimising additional level development. The design consists of ten
semi-independent mining sequences, based on both horizontal and
vertical mining fronts.
Infrastructure
The Infrastructure requirements are based on the Stage 1 PFS and
contemplate the transport of ore from the mine to Telfer via road
trains on an all-weather unsealed road. The road has been designed
to withstand a 1-in-a-100-year flood event and maintain access to
Havieron.
Power is expected to be supplied to Havieron from Telfer's
existing gas power station via a 66 kilovolt (kV) overhead line
running parallel to the nominated haul road corridor. Further
opportunities to replace these with non-fossil fuel power
generation are expected to be evaluated as part of the Feasibility
Study during the Forward Works Program.
Telfer currently operates two processing trains with a total
capacity of 22 Mtpa. The Havieron ore is expected to be processed
through a modified Telfer Train 2 Processing Plant which is
expected to operate a single train at 6Mtpa rate on a campaign
basis. The Plant modifications are expected to include magnetic
separation within the flotation circuit to reduce the amount of
pyrrhotite in the final Cu Concentrate and a carbon-in-leach (CIL)
circuit on the flotation tail and cyanide detoxification circuit.
The expected cost of the plant modifications is included in the
project capital estimate. A single train operation provides
optionality if higher mining rates are achieved from Havieron or
through the extension of Telfer's current mine life (i.e. Telfer
ore can be run through the other train with the existing
flowsheet). Tailings from ore processed is anticipated to be
deposited at the existing Telfer TSF.
Independent Review of the Mineral Resource and Ore Reserve
Update
SRK Consulting (Australasia) Pty Ltd has completed an
independent technical assessment of the Updated Mineral Resource
and Updated Ore Reserve estimates completed by Greatland for the
Havieron deposit. As part of that assessment SRK reviewed the
Resource and Reserve 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 and Ore Reserves 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).
Potential Growth with Ongoing Exploration
The Havieron mineral system as outlined by drill testing to date
is a 650m by 350m ovate shaped north west trending alteration zone
in which mineralisation is hosted by variable brecciation and
sulphide accumulations centred on a complex of nested diorite
intrusions. Higher grade zones are associated with increases in
sulphide accumulations including pyrrhotite, chalcopyrite and
pyrite with quartz. The South East Crescent Zone is a geological
domain characterised by massive sulphide accumulations.
Mineralisation has been observed to over 1,000m in vertical extent
below the 420m of post mineralisation cover sequence.
The Havieron project has significant additional growth potential
including:
-- Upgrading of existing Inferred Mineral Resources in both the
South East Crescent Zone and adjacent Breccias;
-- Extension of the South East Crescent Zone below the Updated
Mineral Resource, where increasing grade and thickness of
mineralisation has been observed in recent drilling;
-- Expansion and infill drilling in the Eastern Breccia; and
-- Potential to discover addition mineralisation centres outside
of the immediate ovoid pipe
At the South East Crescent Zone, growth drilling has reported
significant intersections 200m below the Updated Mineral Resource.
Drilling continues to assess the depth extents of South East
Crescent Zone which now has a vertical extent of over 1,000m.
The deepest drill hole within the resource is HAD133W1,
approximately 850m below the unconformity, with the system open
beneath this hole.
-- HAD133W1
-- 133m @ 7.0g/t Au & 0.05% Cu from 1,446m
-- including 55.9m @ 9.7g/t Au & 0.04% Cu from 1,449.5m
-- including 20m @ 11g/t Au & 0.04% Cu from 1,519m
The true width of this intersection is approximately 60m.
Results external to or below the Mineral Resource include
HAD86W3 and HAD029:
-- HAD086W3
-- 44.7m @ 7.1g/t Au & 0.17% Cu from 1,412m
-- including 20.2m @ 15g/t Au & 0.29% Cu from 1,421m
-- 48m @ 2.2g/t Au & 0.15% Cu from 1,525m
-- including 26.9m @ 3.7g/t Au & 0.26% Cu from 1,538.1m
-- HAD029
-- 134.2m @ 0.81g/t Au & 0.23% Cu from 1,460m
-- including 23m @ 2.7g/t Au & 0.14% Cu from 1,473m
As announced by Greatland on 28 January 2022, HAD086W3 returned
two Crescent Sulphide Zone intersections, with assays for the lower
portion of the drill hole reporting 48m @ 2.2g/t Au & 0.15% Cu
from 1,525m, including 26.9m @ 3.7g/t Au & 0.26% Cu from
1,538.1m. These results along with high grade hole HAD133W1,
approximately 100m to the southeast continue to support extensions
of the South East Crescent Zone at depth. Drilling continues to
assess the depth extents of the South East Crescent Zone which now
has a vertical extent of over 1000m.
At the Eastern Breccia, drilling targeting strike extensions
from previously reported drill holes HAD083 and HAD084 indicate the
potential for the Eastern Breccia to represent a separate North
West trending mineralised corridor, with an alteration footprint of
approximately 600m in strike, adjacent to the ovoid Havieron
breccia system and associated South East Crescent Zone.
Recently reported sulphide rich, Crescent Zone like higher grade
zones appear to be developed internal to this Eastern Breccia
Complex. The most significant intercept to date was returned from
HAD104, reporting 62.5m @ 5.9g/t Au & 0.30% Cu from 1,546.5m,
including 49.4m @ 7.1g/t Au & 0.38% Cu from 1,554.6m. The
intercept is related to massive sulphide and quartz infill, which
is characteristic of the South East Crescent Zone. The intercept is
200m south east of the previously reported Eastern Breccia
drillholes. HAD104 has highlighted the potential for this separate
NW trending Eastern Breccia corridor to host Crescent Sulphide Zone
style high grade mineralisation. Drilling is now focussed on
defining the extents of this higher grade mineralisation seen in
HAD104 which remains open in all directions.
Results For HAD104 include:
-- HAD104
-- 62.5m @ 5.9g/t Au & 0.30% Cu from 1,546.5m
-- including 49.4m @ 7.1g/t Au & 0.38% Cu from 1,554.6m
In addition to this release, a PDF version of this report with
supplementary information can be found at the
Company's website: www.greatlandgold.com/media/jorc/ .
Competent Persons Statements:
Information in this announcement that relates to exploration or
development results has been extracted from the following
announcements:
"Havieron Exploration and Development Update", dated 28 January
2022 (Greatland)
"Quarterly Exploration Report", dated 28 January 2022
(Newcrest)
"Havieron Exploration and Development Update", dated 9 December
2021 (Greatland)
"Exploration Update", dated 9 December 2021 (Newcrest)
"Havieron Exploration and Development Update", dated 28 October
2021 (Greatland)
"Quarterly Exploration Report", dated 28 October 2021
(Newcrest)
"Havieron Maiden Pre Feasibility Study", dated 12 October 2021
(Greatland)
"Havieron PFS Stage 1 delivers solid returns and base for future
growth" dated 12 October 2021 (Newcrest)
"Havieron Development and Exploration Update" dated 9 September
2021 (Greatland)
"Exploration Update", dated 9 September 2021 (Newcrest)
"Havieron Development and Exploration Update" dated 22 July 2021
(Greatland)
"Quarterly Exploration Report", dated 22 July 2021
(Newcrest)
"Further Excellent Growth Drilling Results at Havieron", dated
10 June 2021 (Greatland)
"Exploration Update", dated 10 June 2021 (Newcrest)
"Excellent Growth Drilling Results at Havieron", dated 29 April
2021 (Greatland)
"Quarterly Exploration Report", dated 29 April 2021
(Newcrest)
"Further Outstanding Infill Drilling Results at Havieron", dated
11 March 2021 (Greatland)
"Exploration Update", dated 11 March 2021 (Newcrest)
"Newcrest Reports Further Drilling Results at Havieron", dated
28 January 2021 (Greatland)
"Quarterly Exploration Report", dated 28 January 2021
(Newcrest)
"Newcrest Reports Further Drilling Results at Havieron", dated
10 December 2020 (Greatland)
"Exploration Update", dated 10 December 2020 (Newcrest)
"Initial Inferred Mineral Resource Estimate for Havieron", dated
10 December 2020 (Greatland)
"Initial Inferred Mineral Resource Estimate for Havieron", dated
10 December 2020 (Newcrest)
"Drilling Results at Havieron Highlight Potential New Eastern
Breccia Target", dated 29 October 2020 (Greatland)
"Quarterly Exploration Report", dated 29 October 2020
(Newcrest)
"Latest Drilling Results at Havieron Highlight Potential Bulk
Tonnage Target", dated 10 September 2020 (Greatland)
"Exploration Update", dated 10 September 2020 (Newcrest)
"Newcrest Identifies New Zone of Breccia Mineralisation at
Havieron", dated 23 July 2020 (Greatland)
"Quarterly Exploration Report", dated 23 July 2020
(Newcrest)
"Further Outstanding Drill Results from Havieron", dated 11 June
2020 (Greatland)
"Exploration Update", dated 11 June 2020 (Newcrest)
"Newcrest Reports Further Outstanding Drill Results at
Havieron", dated 30 April 2020 (Greatland)
"Quarterly Exploration Report", dated 30 April 2020
(Newcrest)
"Newcrest Reports Further Outstanding Drill Results at
Havieron", dated 11 March 2020 (Greatland)
"Exploration and Guidance Update", dated 11 March 2020
(Newcrest)
"Further Outstanding Drill Results at Havieron", dated 30
January 2020 (Greatland)
"Quarterly Exploration Report", dated 30 January 2020
(Newcrest)
"New Outstanding Drill Results at Havieron Extend the Strike
Length of High-Grade Mineralisation",
dated 2 December 2019 (Greatland)
"Exploration Update - Havieron", dated 2 December 2019
(Newcrest)
"Further High-Grade Drilling Results from Newcrest's Campaign at
Havieron", dated 24 October 2019 (Greatland)
"Quarterly Exploration Report - September 2019", dated 24
October 2019 (Newcrest)
"Update on Newcrest Drilling Results at Havieron", dated 10
September 2019 (Greatland)
"Exploration Update - Havieron", dated 10 September 2019
(Newcrest)
"First Results from Newcrest's Drilling Campaign at Havieron",
dated 25 July 2019 (Greatland)
"Newcrest Quarterly Exploration Report - June 2019", dated 25
July 2019 (Newcrest)
Information in this announcement pertaining to Reporting of
Exploration Results, including Sampling Techniques and Data, has
been reviewed and approved by Mr John McIntyre, a Member of the
Australian Institute of Geoscientists (MAIG), who has more than 30
years relevant industry experience. Mr McIntyre is an employee of
the Company and has a shareholding in Greatland Gold plc. Mr
McIntyre has sufficient experience relevant to the style of
mineralisation and type of deposit under consideration, and to the
activity which he is undertaking to qualify as a Competent Person
as defined 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 McIntyre consents to the inclusion in this
announcement of the matters based on this information in the form
and context in which it appears. Mr McIntyre confirms that the
Company is not aware of any new information or data that materially
affects the information included in the relevant market
announcements, and that the form and context in which the
information has been presented has not been materially
modified.
Information in this announcement pertaining to Estimation and
Reporting of Mineral Resources, has been reviewed and approved by
Mr Stuart Masters, a Member of the Australian Institute of
Geoscientists (MAIG) and a Fellow of The Australasian Institute of
Mining and Metallurgy (FAusIMM), who has more than 35 years
relevant industry experience. Mr Masters is the Principal
Consultant and Director of CS-2 Pty Ltd, and has no financial
interest in Greatland Gold plc or its related entities. Mr Masters
has sufficient experience relevant to the style of mineralisation
and type of deposit under consideration, and to the activity which
he is undertaking to qualify as a Competent Person as defined 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 Masters consents to the inclusion in this announcement
of the matters based on this information in the form and context in
which it appears. Mr Masters confirms that the Company is not aware
of any new information or data that materially affects the
information included in the relevant market announcements, and that
the form and context in which the information has been presented
has not been materially modified.
Information in this announcement pertaining to Estimation and
Reporting of Ore Reserves, has been reviewed and approved by Mr
Otto Richter, a Member of The Australasian Institute of Mining and
Metallurgy (MAusIMM), who has more than 20 years relevant industry
experience. Mr Richter is an employee of the Company and has no
financial interest in Greatland Gold plc or its related entities.
Mr Richter has sufficient experience relevant to the style of
mineralisation and type of deposit under consideration, and to the
activity which he is undertaking to qualify as a Competent Person
as defined 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 Richter consents to the inclusion in this
announcement of the matters based on this information in the form
and context in which it appears. Mr Richter confirms that the
Company is not aware of any new information or data that materially
affects the information included in the relevant market
announcements, and that the form and context in which the
information has been presented has not been materially
modified.
Notes for Editors:
Greatland Gold plc (AIM:GGP) is a leading mining development and
exploration company with a focus on precious and base metals . The
Company's flagship asset is the world-class Havieron gold-copper
deposit in the Paterson region of Western Australia, discovered by
Greatland and presently under development in Joint Venture with
Newcrest Mining Ltd.
Havieron is located approximately 45km east of Newcrest's Telfer
gold mine and, subject to a positive decision to mine, will
leverage the existing infrastructure and processing plant to
significantly reduce the project's capital expenditure and carbon
impact for a low cost pathway to development. An extensive growth
drilling program is presently underway. Construction of the box cut
and decline to develop the Havieron deposit commenced in February
2021.
Greatland has a proven track record of discovery and exploration
success. It is pursuing the next generation of Tier 1 mineral
deposits by applying advanced exploration techniques in
under-explored regions. The Company is focused on safe, low-risk
jurisdictions and is strategically positioned in the highly
prospective Paterson region. Greatland has a total six projects
across Australia with a focus on becoming a multi-commodity mining
company of significant scale.
Appendix 1
JORC Code, 2012 Edition - Table 1
Section 1: Sampling Techniques and Data
Sampling techniques Diamond drilling core samples are obtained from core
drilling in Proterozoic basement lithologies.
Core is cut along the orientation line and one half
consistently sampled.
PQ-HQ and NQ diameter core was drilled on a 6m run.
Core was cut using an automated core-cutter and half
core sampled at 1m intervals or at breaks for major
geological changes. Sampling intervals range from 0.2
- 2.0m. Sample weights were typically between 0.6 and
5.9 kg. Cover sequences were not sampled.
-------------------- --------------------------------------------------------------------
Drilling techniques Permian Paterson Formation cover sequence was drilled
using mud rotary drilling. Depths of cover typically
observed to 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 double tube
coring configuration with minor HQ and PQ triple tube
configuration. Navi drilling was undertaken to start
wedged holes from parent holes.
Core from inclined drill holes are oriented on 3m and
6m runs using an electronic core orientation tool (Reflex
ACTIII). 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 recovered core
measurements against driller's depth blocks in each
core tray, as recorded in the database. Driller's depth
blocks provided the depth, interval of core recovered,
and interval of core drilled. Core recoveries below
the cover sequence were typically 100%, with isolated
zones of lower recovery. Cover sequence drilling by
the mud-rotary drilling did not yield recoverable samples.
Those sections of wedge holes that were Navi drilled
did not produce recoverable sample material and have
not been sampled.
No specific measures have been taken to maximise recovery,
other than employing professional and well respected
drillers;
There is no discernible relationship between sample
recovery and the grade of any important variable.
-------------------- --------------------------------------------------------------------
Logging Geological logging recorded qualitative descriptions
of lithology, alteration, mineralisation, veining, and
structure (for all core drilled, 209,911 of drilling
from 311 holes drilled up until 2 December 2021, all
intersecting mineralisation), including orientation
of key geological features.
Geotechnical measurements including Rock Quality Designation
(RQD) fracture frequency, solid core recovery and qualitative
rock strength measurements were recorded by Geologists
or Geotechnical Engineers.
All geological and geotechnical logging was conducted
at the Havieron site.
Magnetic susceptibility measurements were recorded every
metre. The bulk density of selected drill core intervals
was determined at site on whole core samples.
Digital data logging was captured on diamond drill core
intervals only, and all data validated and stored in
a Datashed database.
All drill cores were photographed (wet and dry), prior
to cutting and/or sampling the core.
The logging is of sufficient quality to support Mineral
Resource estimates, mining studies and metallurgical
studies
100 percent of recovered core in the basement rocks
has been logged.
-------------------- --------------------------------------------------------------------
Sub-sampling Core was cut and sampled at the Telfer or Havieron core
techniques processing facilities. Half core samples were collected
and sample in pre-numbered calico bags and grouped into bulk bags
preparation for dispatch to the laboratory. Sample weights typically
varied from 0.7 to 5.6kg. Sample sizes are considered
appropriate for the style of mineralisation. Sample
lengths typically ranged from 0.24 to 2m with 54% of
sample being 1m in length. Drill core samples were freighted
by air and road to the laboratory.
Navi drill holes did not produce recoverable material
and have not been sampled.
Sample preparation was conducted at the independent
ISO17025 accredited Intertek Laboratory, Perth (Intertek).
Samples were dried at 105(o) C, and crushed to 95% passing
4.75mm, and then split to obtain up to 3kg sub-sample,
which was pulverised (using LM5) 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.
Coarse Crush and Pulp 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 Datashed database. Field Duplicate samples
are not (routinely) taken.
Sampling and sample preparation sizes and quality control
protocols are considered appropriate to the grain size
of the material being sampled.
--------------------------------------------------------------------
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.
No other analytical methods or tools have been used
in the estimation.
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 the Datashed database
and verified as acceptable prior to use of data from
analysed batches. Batches failing QA/QC tests were re-submitted
for assay.
Laboratory quality control data, including laboratory
standards, blanks, duplicates, repeats and grind size
results are captured in the Datashed database and assessed
for accuracy and precision for recent data.
Extended quality control programs including pulp samples
submitted to an umpire laboratory.
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 Results and Mineral Resources.
--------------------------------------------------------------------
Verification Assessment of reported significant assay intervals was
of sampling verified by re-logging of diamond drill core intervals
and assaying and assessment of high-resolution core photography.
The verification of significant intersections has been
completed by Newcrest personnel and Newcrest's Competent
Person/Qualified Person.
No twinned holes have been drilled, however there are
many 'wedge/daughter' holes that provide close-spaced
intersections in adjacent holes.
Sampling intervals defined by the geologist are electronically
assigned sample identification numbers prior to core
cutting. Corresponding sample numbers matching pre-labelled
calico bags are assigned to each interval. 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 Datashed
database.
No adjustments are made to any assay data.
There are no currently known drilling, sampling, recovery,
or other factors that could materially affect the accuracy
or reliability of the data.
--------------------------------------------------------------------
Location of Drill hole collar locations were surveyed using a differential
data points GPS with GNSS with a stated accuracy of +/- 0.5m 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.
All collar coordinates are provided in the Geocentric
Datum of Australian (GDA20 Zone 51). All relative depth
information is reported in AHD +5000m.
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. Easting
and Northing coordinates are provided in the Geocentric
Datum of Australian (GDA20 Zone 51) and all vertical
level information is reported in AHD +5000m.
-------------------- --------------------------------------------------------------------
Data spacing Within the South East Crescent Zone and Breccia Zone
and distribution and Eastern Breccia drill hole spacing ranges from 50
by 100m, to 50 by 50m within the current resource extents.
Outside the resource boundary drill hole spacing ranges
from 50 to 200m in lateral extent within the Breccia
Zone over an area of 2km2.
The data spacing is sufficient to establish the degree
of geological and grade continuity appropriate for the
Mineral Resource and Ore Reserve estimation procedure(s)
and classifications applied.
Samples have not been composited.
-------------------- --------------------------------------------------------------------
Orientation Drill holes targeting the Crescent Zone are oriented
of data in to intersect the steeply dipping high-grade sulphide
relation to mineralisation zones at an angle of greater than 40
geological degrees. As such, the drilled length of reported intersections
structure is typically greater than true width of mineralisation
in this Zone. Most of these holes also intersect the
adjacent Breccia Zones.
Drill holes targeting the Breccia Zones are oriented
to intersect at angles either broadly perpendicular
to the adjacent Crescent Sulphide Zones, or if drilling
away from the South East Crescent Zone area, at intersections
broadly perpendicular to the elongation of the ovoid
breccia body. Given the lower level of understanding
of the breccia geometries it is not possible to quantify
the relationship between drilled and true length of
reported intersections in these Zones.
The attitudes of the South East Crescent Zone and Main
(Northern) Breccia Zone and the variety in drilling
orientations through such suggest no sample orientation
related biases affect these zones.
The Eastern Breccia, which is interpreted to strike
north-westerly and dip steeply, is intersected almost
exclusively with moderate-steep west-to-east drilling.
-------------------- --------------------------------------------------------------------
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 initially
completed by Newcrest personnel at the Telfer facility
but later done at the Havieron facility once it was
operational.
Samples were freighted in sealed bags by air and road
to the Laboratory, within 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 advice issued to Newcrest.
Details of all sample movement 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 by Newcrest (JV Manager) of the core
reviews handling, sample preparation and assays laboratories
are conducted on a regular basis by both project personnel
and owner representatives and have not identified any
material issues affecting the reliability of the sampling
techniques and data.
In the Competent Person's opinion, the sample preparation,
security and analytical procedures are consistent with
current industry standards and are 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. No drilling,
sampling or recovery factors that materially impact
the reliability of the results of the drilling programme
have been identified.
-------------------- --------------------------------------------------------------------
Section 2: Reporting of Exploration Results
Mineral tenement The Havieron Project is located within mining tenement
and land tenure M45/1287 and is jointly owned by Greatland Pty Ltd and
status Newcrest Operations Limited ("Newcrest") . Newcrest
has entered into a Joint Venture Agreement (effective
30 November 2020) and Farm-In Agreement (effective 12
March 2019) with Greatland Pty Ltd and Greatland Gold
plc. Newcrest currently holds a 60% joint venture interest
and is entitled (subject to the terms of the Joint Venture
Agreement) to an additional 10% interest, giving an
aggregate interest of 70% (Greatland 30%). Newcrest
also has an option to acquire a further 5% joint venture
interest at fair market value.
Newcrest and the WDLAC are parties to an ILUA which
relates to the use of native title land for Newcrest's
current operations at Telfer and its activities within
a 60-km radius around Telfer and includes its exploration
activities at Havieron. The parties have agreed that
the ILUA will apply to any future development activities
by the Joint Venture Participants (Newcrest and Greatland)
at Havieron.
The mining tenement M45/1287 was granted on 10 September
2020.
-------------------------------------------------------------------
Exploration Newcrest completed six core holes in the vicinity of
done by other the Havieron Project from 1991 to 2003. Greatland Gold
parties completed drill 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.
-------------------------------------------------------------------
Geology The Havieron Project is located within the north-western
exposure of the Palaeo-Proterozoic to Neoproterozoic
Paterson Orogen (formerly Paterson Province), 45 km
east of Telfer. 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 a
650m by 350m ovoid area, and to depths of up to 1500m
below surface.
-------------------------------------------------------------------
Drill hole Not applicable as this release does not include new
Information Exploration Results. Refer to previous exploration releases
for drillhole information of the previously reported
intercepts highlighted in this report and used in the
Mineral Resource Estimate.
-------------------------------------------------------------------
Data aggregation Not applicable as this release does not include new
methods Exploration Results. Refer to previous exploration releases
for drillhole information of the previously reported
intercepts highlighted in this report and used in the
Mineral Resource Estimate.
-------------------------------------------------------------------
Relationship Not applicable as this release does not include new
between mineralisation Exploration Results. Refer to previous exploration releases
widths and for drillhole information of the previously reported
intercept intercepts highlighted in this report and used in the
lengths Mineral Resource Estimate.
-------------------------------------------------------------------
Diagrams Diagrams outlining the extent of the Updated Mineral
Resources and Updated Ore Reserves compared to the Stage
1 PFS Resources and Reserves are shown in the body of
the announcement.
Otherwise not applicable as this release does not include
new Exploration Results.
-------------------------------------------------------------------
Balanced reporting This report includes highlights of drilling from previously
released drillhole intercepts. There have been twenty
one Exploration Results releases for this project made
by Newcrest and Greatland. Previous release dates are
25 July 2019, 10 September 2019, 24 October 2019, 2
December 2019, 30 January 2020, 11 March 2020, 30 April
2020, 11 June 2020, 23 July 2020, 10 September 2020,
29 October 2020, 10 December 2020, 28 January 2021,
11 March 2021, 29 April 2021, 10 June 2021, 22 July
2021, 9 September 2021, 28 October 2021, 9 December
2021 and 28 January 2022.
Previous exploration programs conducted by Newcrest
and Greatland have been reported. Exploration drilling
programs are ongoing and further material results will
be reported in subsequent releases.
-------------------------------------------------------------------
Other substantive Not applicable as this release does not include Exploration
exploration Results.
data
-------------------------------------------------------------------
Further work Infill and/ or extension drilling is underway on the
Inferred Mineral Resource portion of the South East
Crescent Zone, looking to upgrade a significant portion
of the Inferred Mineral Resource to Indicated Mineral
Resource; extension and infill of the Eastern Breccia.
Growth drilling is underway to extend the limits of
the mineralised system down depth and looking to establish
additional resources outside those stated in this announcement.
-------------------------------------------------------------------
Section 3: Estimation and Reporting of Mineral Resources
Database integrity Data logged or received by Newcrest are stored in a
SQL acQuire 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 Datashed
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 2021, during which he inspected drilling,
sampling, logging, selected drill core, the core cutting
facility which was inactive at the time 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,
interpretation including 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 domains (Havieron and
Eastern breccias), and several unmineralised zones (Dolerite
Dyke, Calc-silicate country rocks, Permian sequence
and Cover). These zones are based on grouped primary
logging domain codes interpreted from drill cores, mineralogical
logs and assay data. GPL has incorporated much of the
previously reported Actinolite Breccia (ACBX) 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 a increase
in grade, but these diorites have not been modelled.
However, their impact is represented to a large extent
by the choice of search neighbourhood parameters.
The confidence in the location and geometry of Crescent
Zone is generally high but decreases as the informing
data become more sparse. In some places there is no
distinct grade boundary with the adjacent breccias (especially
for gold, copper and sulphur) and a "buffer" zone was
interpreted to represent such, but analysis of this
zone did not support its use in the final model.
The confidence in the location and geometry of the breccias
in the Havieron Breccia zones is variable, but considered
moderate in the densely drilled parts of such. However,
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 breccias
in the Eastern Breccia zones is variable, but decreases
as the informing data become more sparse. As such, this
model is not a suitable basis for assessing selective
mining options for these zones. In addition, almost
all of the drill holes intersecting these breccias trend
from west-to-east.
The confidence in the location and geometry of the Dolerite
Dyke, Calc-Shales and Base of Permian is very high given
their relative importance to the resource estimates.
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 Crescent Zone is generally very well defined and
it is difficult to generate an alternative, plausible
and materially different zone from the available data.
The zone is typically intersected where expected by
new drilling.
The Breccia zones are reasonably well defined at a large
scale but are much less well defined at the short scale
owing to the low geological and grade continuity of
such. 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 Crescent
Zone Mineral Resource extents are 550m in unfolded
plan section, between 5-40m true width and 1000m in
vertical extent, mineralisation remains open at depth.
The Breccia Mineral Resource extents occurs as a 50-100m
sleeve marginal to the Crescent Zone Mineral Resource
and also a 250x50x300 NW trending zone in the north
western half on the breccia complex, the "Northern Breccia"
which remains open at depth and to the northwest.
The Eastern Breccia Mineral Resource has dimensions
of 200m strike x150m width x 250m vertical extent.
------------------- -------------------------------------------------------------------
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 2 December
2021 confirmed that the gold and copper grade distributions
showed that the Breccia Zones are moderately diffusive
in nature, and the Crescent Zone is relatively weakly
diffusive in nature. Even though the 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. That review also broadly
confirmed the validity of the variogram models and search
neighbourhoods used by Newcrest for the Stage 1 PFS
Model, although Greatland refined the parameters based
on the more extensive data set and an improved approach
to unfolding for the Crescent Zone.
Composite data for gold, copper and bismuth 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 used a 'manual unfolding' method (undertaken
in Micromine) for the Crescent Zone that yielded more
robust variograms and subsequently greater confidence
in the variogram models and estimates of gold and copper
for this zone (note that the model blocks were also
unfolded, but this meant 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 GPL. Whilst the unfolding
was not perfect, it was considered to be an improvement
on the previous approach.
Greatland used a 'trend model' method (undertaken in
Micromine) to guide the estimation of grade and density
for the 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.
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 Crescent
Zone and other domains. A transitional boundary of around
20m was used between the Cemented and Crackle Breccias
to reflect the variable nature of this boundary. Only
blocks 10m 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 (rather than IDW previously)
on a domain-wise basis owing to the more extensive database
for this model. 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 Crescent domain capturing the high iron and sulphur
grades, and thus density, very well.
Gold and copper were estimated in a single pass for
each domain, whereas bismuth and density were estimated
using two-passes. Bismuth was primarily estimated in
2 passes to better honour its spatially bimodal distribution.
Around 30% of the Inferred resources in the Eastern
Breccia are based on composites with a closest distance
to the block of more than 30m and data from less than
4 holes, which GPL has used to define extrapolation.
These blocks are mainly on the edges of the domain as
exhibited in the following plan views at 60m intervals
of the extrapolated blocks colour coded by distance
to nearest informing composite (interpolated blocks
not shown for clarity), as well as the location of the
informing composites (window +/-10m)
The following table shows the proportion of resource
tonnage where the nearest informing composite is more
than 30m away from the block by domain and category:
Grades and density were estimated in Micromine 2022
software.
The sensitivity of the 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 Crescent
and Havieron Breccia domains. The Eastern Breccia domain
is assumed to have similar metallurgical properties
to the Havieron Breccia domain. The resource does not
include any by-products.
Bismuth has been estimated into the gold-based domains
using a similar approach as for estimating gold and
copper, but with bismuth-specific parameters and a two-pass
search plan.
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
Crescent Zone, where the data density ranges from 50-100m
. Whilst Micromine does not currently support parent-cell
estimation for an unfolded model such as this, the impact
of such is deemed negligible. However, this size is
considered small for the Breccia Zones, even though
parent-cell estimation was used for such. Having said
this, resources in this domain have been reported using
NSR-based shells that mitigate most of the detrimental
effects of the block size.
The Crescent Zone is almost exclusively estimated to
be above the cut-off grade and minimum stoping thickness
(around 4m). 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. Whilst copper is less well correlated
to gold, the gold domains are considered appropriate
for estimating copper. Within these domains gold, copper
and bismuth grades have been estimated independently.
Given that each of these elements is assayed for each
sample and the complexities involved in such, the need
for co-estimation, such as co-kriging, was deemed unnecessary.
Other key variables, such as iron, sulphur and cobalt,
which Newcrest showed to be well correlated, were not
assessed in great detail or co-estimated as they are
not important for the purposes of this model (i.e.,
they are not inputs into metallurgical recovery or NSR
formulae).
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 parameters As Havieron is a multi-element deposit, a Net Smelter
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 account
revenue factors, metallurgical recovery assumptions,
transport costs, refining charges, penalties and royalty
charges with the gold price of US$1,600 per ounce, copper
price of US$3.50 per pound (US$7,175/t) and an USD:AUD
exchange rate of 0.73. Commodity prices and exchange
rate forecasts were based on the average between Long
Term 3rd Quartile and Forward Curve price forecasts,
as sourced from Consensus Economics and Bloomberg.
The nominal cut-off value for resource reporting depends
on the style and geometry of mineralisation with the
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 Crescent Zone) is estimated at A$80 NSR/t,
and accounts for mining, haulage, processing and general
and administration costs, which are based on the Stage
1 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 Crescent Zone. The vast majority
(94%) of the estimated Crescent Zone material reports
above the A$80 NSR/t, as such domaining all material
below this cut-off is not practicable. Areas of Crescent
Zone material that had a higher frequency of blocks
below A$80 NSR/t were removed from the classification.
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 Version 2021.1.3 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 SE Crescent Mineral Resources and Breccia Mineral
Resources are representing the limit of reasonable prospects
of eventual economic extraction. The A$80 NSR/t cut-off
for SE Crescent Mineral Resources and A$50 NSR/t cut-off
for Breccia Mineral Resources are based on current understanding
of the Havieron deposit and other benchmarked operations.
Greatland used smoothed NSR shells to define its resources
and this results in some material below the nominal
cut-off to be included in the resources. The following
table shows the total and proportion of the Mineral
Resource tonnages and average NSR/t's below the nominal
cut-off NSR each Domain/Lode/category combination.
------------------- -------------------------------------------------------------------
Mining factors The Stage 1 PFS showed that the 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 Stage 1 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. Whilst SLC would likely require a temporary
pillar near the top to act as a buffer between the cave
and the Permian cover, this material may be recoverable
as part of the cave draw and so it is not excised from
the Mineral Resources. Furthermore, 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
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 or on a campaign basis through the Telfer Train 2 Treatment
assumptions Plant 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 38 variability samples during the Havieron
Concept Study (2020) and Stage 1 PFS (2021) with good
spatial coverage of the Crescent Zone Domain. Of the
38 samples, 8 samples are located in the Havieron Breccia
Zones and 30 samples are located in the Crescent Zone
Domain, of which 21 samples are located within the Indicated
Mineral Resources in this domain. Based on these samples,
metallurgical recoveries for gold are anticipated to
average approximately 88% and recoveries of copper are
expected to average approximately 84% throughout the
life of the project. Note that GPL does not have any
metallurgical testwork results for the Eastern Breccias
and it is assumed that they have similar metallurgical
properties to their corresponding Havieron Breccias.
------------------- -------------------------------------------------------------------
Environmental Detailed environmental studies have been undertaken
factors or in the Project area and include flora and vegetation,
assumptions fauna, 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 (WDLAC), 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 Gold 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 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 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 to 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 to be suitable for the purposes
of resource estimation.
Geological and grade continuity in the 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
are typically much lower. However, the data density
is moderate-high in the southern parts of the Breccias
adjacent to the 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 2022 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 Crescent Zone and
accuracy / Breccia Zones. These studies revealed that the estimates
confidence for the 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.
------------------- -------------------------------------------------------------------
Section 4: Estimation and Reporting of Ore Reserves
Mineral Resource Havieron is a gold and copper deposit located within
Estimate for the boundaries of the East Pilbara Shire in the Paterson
conversion Province, Western Australia (WA), and is located approximately
to Ore Reserves 45 kilometres (km) east of Newcrest's fly-in fly-out
Telfer Mine. The Havieron deposit lies unconformably
below approximately 420 metres (m) of post-mineral,
flat-lying Permian fluvio-glacial sediments of the basal
sequence rocks in the Palaeozoic Canning Basin.
The geology model represents several mineralised zones,
including 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 domains (Havieron and Eastern
breccias), and several unmineralised zones (Dolerite
Dyke, Calc-silicate country rocks, Permian sequence
and Cover). These zones are based on grouped primary
logging domain codes interpreted from drill cores, mineralogical
logs and assay data.
The February 2022 Updated Mineral Resource Estimate
(Updated Mineral Resource) was used as the basis for
the February 2022 Ore Reserve Update. Mineralisation
of gold and copper in the Updated Mineral Resource are
within the Crescent and the Breccia Zones. High grade
gold mineralisation is associated with a massive sulphide
zone termed the Crescent Zone which occurs on the margin
of the Breccia. The Crescent Zone is characterised by
a series of massive to semi-massive sulphide replacement
units that have a subvertical dip and is best developed
on the SE of the system forming as arcuate, crescent
like geometry.
The Crescent Zone is 5-40 m wide, extending 700m in
length in unfolded section from the basement contact
and defined over 1,000 m vertically, tapering to 600
m in length and open at that depth. The South East Crescent
Zone has continued to be the focus of drilling and has
been progressively infilled to a nominal drill spacing
of 50m for the Indicated Mineral Resources, and 75m
spacing for the Inferred Mineral Resources.
OK estimation has been used for gold, copper, bismuth
and density. A panel size of 20 mE x 20 mN x 20 mRL
was used for both the SE Crescent and Breccias with
sub-blocking allowed down to a size of 4 mE x 4 mN x
4 mRL.
The Updated Mineral Resource estimate for the South
East Crescent has been classified as Indicated Mineral
Resource and Inferred Mineral Resource based on data
quality and quantity factors as well as geological domaining,
estimation confidence and reasonable prospect of the
eventual economic extraction (RPEEE).
The Updated Mineral Resource is reported inclusive of
Ore Reserves.
------------------------------------------------------------------
Site Visits Greatland's Competent Person for the Ore Reserve estimate
visited site in November 2021. A general Havieron site
tour was conducted of the camp, boxcut and decline,
exploration drilling, core farm, and of the Telfer camp
and processing plant. Operational challenges were noted
with unconsolidated material in the upper part of the
decline and discussions were held with the operations
team and decline contractor regarding trials underway
to determine optimal cut length, development cycle and
support measures to ensure the effective progress of
the decline.
Newcrest stated on 17 February 2022 as part of their
Half Year Results Update that the decline experienced
difficulty in poor ground conditions during the early
stages. The team is working to understand the impact
on the development schedule and this may also impact
on vertical development. First production ore is expected
in FY24 (rather than H1 FY24) and more updates will
be provided as information comes to hand..
The Competent Person has undertaken sufficient investigations
of the mine plan and material Modifying Factors applied
to create the mine plan to satisfy himself that the
Ore Reserves have been appropriately estimated and reported
in compliance with the 2012 edition of the JORC Code.
------------------------------------------------------------------
Study Status A Stage 1 PFS was completed to generate the supporting
basis for the maiden Havieron Ore Reserve Estimate published
in October 2021. The mine design and schedule were updated
in February 2022 to reflect the resource model changes
presented in the February 2022 Resource Model Update
and forms the basis for this Ore Reserve Update. This
update is considered to remain at a Pre-Feasibility
level of confidence and shows that the mine plan remains
technically achievable and economically viable taking
into consideration currently known material Modifying
Factors.
------------------------------------------------------------------
Cut-off Parameters The Ore Reserve employs a value-based cut-off determined
from a Net Smelter Return (NSR) to account for the contributions
from multi-elements, at a value equal to the site operating
cost. 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
Metal price assumptions are as listed in the relevant
"Revenue Factors" section. The underlying cost assumptions
remained largely the same between the October 2021 Stage
1 PFS and this February 2022 Update, and is in line
with the 3 Mtpa Investment Case presented in the Stage
1 PFS.
The NSR calculation takes into account revenue factors,
metallurgical recovery assumptions, transport costs,
refining charges, and royalty charges.
The site operating costs include mining cost, processing
cost, relevant site general and administration costs
and relevant sustaining capital costs. This cost equates
to a break even cut off value of approximately AUD95/t
milled, and a marginal cut off value of approximately
AUD80/t milled.
Metallurgical recovery and cost assumptions are discussed
in more detail under the relevant headings in Table
1 - Section 4.
------------------------------------------------------------------
Mining factors Estimation of the Ore Reserve Update is based on the
or assumptions February 2022 Resource Model Update and involved standard
steps of mine optimisation, mine design, production
scheduling and financial modelling. The basis of the
analysis is an update to the Stage 1 PFS and is considered
to remain at a Pre-Feasibility Level of confidence.
The Ore Reserve Update supports the appropriateness
of the selected mining method (Sub-Level Open Stoping)
at a 3 Mtpa mining rate as the basis of the Ore Reserve
estimate.
Back fill type Cemented paste
fill
-----------------
Materials handling system Decline trucking
-----------------
Stope dimensions Width Minimum 5m
to Maximum
30 m
---------- -----------------
Length 15 to 20 m
----------------------------- -----------------
Sublevel 25 to 60m,
height average 50m
----------------------------- -----------------
The following Modifying Factors have been applied to
all mining shapes to accurately represent the expected
mined tonnes and grades :
* Dilution factors for overbreak in primary, secondary
and tertiary stopes (average 9%), consisting of waste
(average 6%) and stope paste (average 3%); Dilution
tonnes were estimated as an equivalent depth of
failure based on geotechnical estimations, applied to
the individual stope walls and in the respective
stoping sequence, to estimate paste and waste rock
volumes and expressed here as an average percentage
of the overall stope tonnes.
* Dilution included at zero grade; and
* Mining recovery factor of 97.5%, based on the near
vertical nature of the stopes, proposed mining method
and geotechnical estimation of overall stope
stability.
The ultimate extent of the deposit remains open and
orebody knowledge will increase as drilling and mining
progress. Current mining modifying factors are based
on known data to date and may change as new information
becomes available.
The February 2022 Resource Model is comprised of Indicated
Mineral Resources and Inferred Mineral Resources. Mine
plans are based on the definition of mining shapes only
considering the contribution of metal from Indicated
Mineral Resources.
Ore Reserves estimates and statements are required to
include estimates of dilution. The dilution included
in the total Ore Reserve is approximately 2.7Mt which
is comprised of Inferred and Unclassified Mineral Resources,
waste host rock and paste fill dilution. Metal from
the Inferred and Unclassified Mineral Resource material
was not considered in the economic assessment of the
stopes.
The Havieron Project is a greenfield mining project
and will require the following mining infrastructure
to support the mine:
* decline, accesses to the levels, ore passes,
ventilation raises and other underground excavations
* paste fill plant and underground distribution system
* ventilation fans, regulators and refrigeration
equipment
* dewatering, electrical distribution and other service
equipment
Non-mining infrastructure is discussed in more detail
under the Infrastructure section.
Metallurgical It is anticipated that Havieron underground ore will
factors or be processed on a campaign basis through the existing
assumptions Telfer Train 2 Treatment Plant circuit at a throughput
of approximately 3 Mtpa, with tailings being disposed
in the current Telfer Tailings Storage Facility. Metal
recovery is anticipated to be through conventional flotation
to produce a copper/gold concentrate and 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 38 variability samples during the Havieron
Concept Study (2020) and Stage 1 PFS (2021) with good
spatial coverage of the Crescent Zone. Of the 38 samples,
8 samples are located in the breccia zones and 30 samples
are located in the Crescent Zone, of which 21 samples
are located within the Crescent Zone Indicated Mineral
Resources. Based on these samples, average life of mine
metallurgical recoveries are estimated to be:
* gold: approximately 88%, and
* copper: approximately 84%, variable on block metal
grade.
Bismuth is the key deleterious element for the gold/copper
concentrate product with smelter penalties incurred
on the basis of bismuth content. It is anticipated that
the impact of bismuth in concentrate will be managed
by mine sequencing and concentrate blending.
Bulk sample or pilot scale test work has not been undertaken.
--------------------------------------------------------------------
Environmental Detailed environmental studies have been undertaken
in the project area and include flora and vegetation,
fauna, 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 (WDLAC), 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 Gold 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 approvals
to accept Havieron tailings in existing tailings storage
facilities.
--------------------------------------------------------------------
Infrastructure Havieron is a greenfield mining project and will require
the following infrastructure to support mining operations:
* Ventilation fans and refrigeration equipment;
* Paste plant;
* Surface Mining Infrastructure Area (MIA) including
camp, offices, workshops, evaporation ponds,
electrical substations, explosive magazines, batch
plant, waste dumps, ore stockpile, and other
facilities;
* Haulage road and Service Corridor to transport the
ore from Havieron to the Telfer Processing Plant and
run overhead powerlines along the Service Corridor to
extend electrical power from the existing Telfer gas
fired power station to Havieron; and
* Modifications to the existing Telfer Processing plant
to treat the ore coming from Havieron.
The capital and operating costs for the above have been
estimated in the Stage 1 PFS. The infrastructure estimates
for this Ore Reserve Update remains in line with the
Stage 1 PFS, with additional allowance made for ventilation
and processing due to a slightly deeper ultimate depth
and in line with the expanded mine plan.
Access to Telfer Mine is already in place via the Telfer
Access Road. Telfer Mine has an existing camp, sealed
runway and airport, gas-fired power station and processing
plant.
--------------------------------------------------------------------
Costs Capital and operating costs underlying assumptions are
to a PFS level. Capital cost estimates are based on
multiple market prices across all technical disciplines
and include processing upgrade and mine development
costs along with associated surface and underground
infrastructure, project establishment and sustaining
capital costs. These provisions have been allowed for
during the life of the mine based on the Stage 1 Study
estimates. Contingency has also been factored into the
project capital cost estimate consistent with the level
of accuracy of the study.
Newcrest stated on 17 February 2022 as part of their
Half Year Results Update that the decline experienced
difficulty in poor ground conditions during the early
stages. The team is working to understand the impact
on the development schedule and this may also impact
on vertical development. First production ore is expected
in FY24 (rather than H1 FY24) and more updates will
be provided as information comes to hand.
The operating cost estimates are in line with the Stage
1 PFS, which were sources from current Telfer rates
and contractor schedule of rates submitted for PFS budget
purposes and are inclusive of:
* mining cost: development by drive type and ground
support profile, longhole drilling and blasting,
haulage for ore and waste, labour, maintenance and
other fixed costs
* electrical power cost based on estimated power
consumption and supply from Telfer Power Plant
* surface transport cost to Telfer Processing plant
* processing cost and
* relevant site general and administration costs.
Ore Reserve cost estimates have been independently reviewed
and are considered to be at an appropriate level for
a PFS .
The Stage 1 PFS transport and refining charges have
been developed from first principles consistent with
the application of the current Telfer operation. These
included charges for deleterious elements, e.g. bismuth
where applicable. These assumptions and estimates were
carried forward into the February 2022 Update.
Costs include a revenue-based payment from mining the
Havieron Project area under the ILUA with WDLAC.
State royalties are 2.5% for gold, 5% for copper after
allowable deductions.
--------------------------------------------------------------------
Revenue factors Long term metal prices and exchange rate assumptions
adopted for estimating this Ore Reserve Update are US$1,450/oz
for gold, US$3.23/lb for copper, at a USD:AUD exchange
rate of 0.73. Commodity prices and exchange rate forecasts
were based on the Median Long Term price forecasts,
as sourced from Consensus Economics and Bloomberg. These
price assumption are higher than the US$1,300/oz for
gold and US$3.00/lb for copper and USD:AUD exchange
rate of 0.75 assumed for the October 2021 Stage 1 Study,
but were selected in line with median long term consensus
price forecasts and historical metal prices over the
past 5 years.
An NSR value calculation was adopted, taking into account
Ore Reserve revenue factors, metallurgical recovery
assumptions, transport costs and refining charges and
royalty charges.
--------------------------------------------------------------------
Market assessment Gold will be sold on the open market and subject to
price fluctuations. Supply and demand for gold from
Telfer and Havieron is not considered a constraint in
the estimation of the Ore Reserve.
Telfer has sold copper concentrate for its operational
life into the world concentrate markets and this is
assumed to continue under conditions similar to Newcrest's
current market agreements over the life of the operational
plan.
Concentrate volume forecasts were derived from the Updated
Ore Reserve production schedule.
--------------------------------------------------------------------
Economic The Ore Reserve has been evaluated through a financial
model on a real cashflow basis. All operating and capital
costs as well as revenue factors stated in this document
were included in the financial model. A discount factor
of 4.5%pa real was applied. This process demonstrated
the Havieron Ore Reserve to have a positive NPV at current
assumptions.
Sensitivities were conducted on the key input parameters
including commodity prices, capital and operating costs,
ore grade, mined tonnes, exchange rate and metallurgical
recoveries confirming the estimate to be robust.
--------------------------------------------------------------------
Social The traditional landowners, the Martu people and the
WDLAC are key project stakeholders. The Martu hold exclusive
possession native title rights and interests over more
than 130,000km(2) of land, including to all points around
the Telfer mine and Havieron Project. The ILUA with
WDLAC, centred on the Telfer mine, extends to the Havieron
Project.
--------------------------------------------------------------------
Other The only identified material naturally occurring risk
at Havieron is flooding from large rain events typically
associated with the cyclone season. The existing boxcut
has been located and all other surface connections to
the surface have been designed above a modelled 1 in
1,000 year Average Recurrence Interval (ARI) event where
possible, or will be elevated such that large volumes
of water cannot enter the mine workings.
A number of State and Commonwealth statutory requirements
are relevant to the Havieron Project and all aspects
of the Project will comply with the relevant Government
Acts and Regulations applicable in the jurisdiction
of Western Australia.
Approvals
A Mining Lease has been granted over the orebody, and
miscellaneous licence granted along the existing service
corridor.
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. Minor additional approvals are in the
process of being obtained and include a Groundwater
Licence amendment and Part V approval to allow the operation
of the evaporation ponds, waste water treatment plant
and to allow construction of a landfill for non-mineralised
waste.
The Part V licence and registrations have approved Works
Approvals and detailed consultation regarding the Groundwater
Licence and associated Water Management Plan has occurred.
The approvals for Stage 2 consist of both Commonwealth
and State level approvals with engagement well advanced
with all regulatory bodies. The approvals timelines
outlined in the Stage 1 PFS are considered achievable.
Stage 2 approvals are expected to consist of a SLOS
underground mine, permanent infrastructure corridor,
associated infrastructure and changes to Telfer approvals
(processing of Havieron ore, Tailings Storage Facility
8 [TSF8] raise to accept Havieron tailings), groundwater
use at Havieron.
For Stage 2 approvals, an additional miscellaneous licence
will be applied for to secure access for an infrastructure
corridor to connect Telfer and Havieron (haul road,
powerlines, water pipes). This is not considered a risk
to the timelines or project.
--------------------------------------------------------------------
Classification The Ore Reserve classification is based on Indicated
Mineral Resources only. No Measured Mineral Resources
are stated for this deposit. This classification is
based on geological confidence as a function of continuity
and complexity of geological features; data spacing
and distribution and estimation quality parameters including
distance to informing samples for block grade estimation.
Inferred Mineral Resource material contained within
the mine plan shapes were set to zero grade and tonnes
treated as internal dilution. It is the Competent Person's
view that the classifications used for the Ore Reserves
are appropriate.
--------------------------------------------------------------------
Audits or The Ore Reserve Update mine design and schedule was
reviews conducted by Entech Pty Ltd, which included a review
of the input assumptions. Entech found the input assumptions
to be within accepted industry practice and suitable
for the level of study.
SRK Consulting (Australasia) Pty Ltd has completed an
independent technical assessment of the 2022 Ore Reserve
estimates completed by Greatland for the Havieron gold
and copper deposit. As part of that assessment, SRK
reviewed the reserve 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 Ore Reserves 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 The accuracy of the estimates within this Ore Reserve
of relative is mostly determined by the order of accuracy associated
accuracy/ with the Mineral Resource estimate, the geotechnical
confidence inputs and the cost factors used.
The Competent Person views the Havieron Ore Reserve
a reasonable assessment of the global estimate. Some
risk and opportunity is associated with the Ore Reserve
process due to the greenfield nature of the mining component
of project, and the brownfields nature of the Telfer
Mine camp, process plant, power generation and related
surface infrastructure. Remaining areas of uncertainty
at this stage are associated with:
* Cost base assumptions rely on current technology and
macroeconomic factors. Changes to these assumptions
will have an impact on the Ore Reserve estimate.
* The Modifying Factors (key inputs) for Ore Reserve
estimation rely upon the geology and geotechnical
data inherent to the orebody. This data, such as
geological structures and rock mass properties, is to
the appropriate definition and has been applied
within the Stage 1 PFS, however further orebody data
is required to confirm the geological and
geotechnical information and is planned as part of
the Forward Works Program.
* Newcrest stated on 17 February 2022 as part of their
Half Year Results Update that the decline experienced
difficulty in poor ground conditions during the early
stages. The team is working to understand the impact
on the development schedule and this may also impact
on vertical development. First production ore is
expected in FY24 (rather than H1 FY24) and more
updates will be provided as information comes to
hand.
* Mining throughput rate is based on equipment
simulation studies considering the planned mine
design and indicated that the 3 Mtpa through rate
adopted in the study is appropriate, but is
considered to be at the higher end of industry
benchmark results. It is planned to be further
investigated during the Forward Works Program.
--------------------------------------------------------------------
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