Significantly Increases Wharekirauponga
Resources in New
Zealand
/NOT FOR DISSEMINATION OR DISTRIBUTION IN
THE UNITED STATES AND NOT FOR
DISTRIBUTION TO US NEWSWIRE SERVICES./
BRISBANE, March 31,
2022 /CNW/ - OceanaGold Corporation (TSX: OGC) (ASX:
OGC) ("OceanaGold" or the "Company") is pleased to provide its
annual Resource and Reserve ("R&R") statement for the year
ended 31 December 2021.
Highlights
- Wharekirauponga ("WKP") Indicated Resource increased 53% from
1.0 million tonnes ("Mt") at 13.4 g/t gold for 0.42 million ounces
("Moz") gold including 0.8 Moz silver to 1.5 Mt at 13.5 g/t gold
for 0.64 Moz gold including 1.27 Moz silver. Inferred Resources of
2.3 Mt at 9.4 g/t gold for 0.7 Moz of gold including 1.6 Moz of
silver remain, presenting a significant opportunity for future
resource conversion.
- Year-on-year increase of 0.31 Moz Measured and Indicated
Resources at Waihi, New Zealand,
to 13.9 Mt at 4.81 g/t gold for 2.15 Moz gold, due to the
conversion of Inferred Resources at Martha and WKP underground
projects.
- Includes first Indicated Resources for the Palomino underground
deposit at Haile, U.S.A; 2.3 Mt at
2.79 g/t gold for 0.20 Moz of gold. Inferred Resources of 3.6 Mt at
2.3 g/t gold for 0.26 Moz remain to be converted.
- Proven and Probable Reserves stood at 131 Mt at 1.33 g/t gold for 5.63 Moz gold,
including 8.02 Moz silver and 0.15 Mt copper, a 0.43 Moz gold
decrease year on year mainly due to mining depletion.
- Measured and Indicated Resources, inclusive of Mineral Reserves
stood at 199 Mt at 1.43 g/t gold for 9.13 Moz gold, including 14.4
Moz silver and 0.17 Mt copper, a 0.92 Moz gold decrease year on
year largely due to mining depletion and a reduction in the
Round Hill open pit resource at
Macraes, New Zealand.
Scott Sullivan, Acting President
and CEO of OceanaGold said, "The recent resource conversion drill
results and updated Indicated and Inferred Resources highlight WKP
has the makings of a quality gold mine. The 2021 drill program at
WKP saw a very high conversion rate of Inferred Resources to
Indicated Resources which resulted in the significant increase in
Indicated Resources from 1.0 Mt at 13.4 g/t gold for 0.42 Moz gold
to 1.5 Mt at 13.5 g/t gold for 0.64 Moz gold including 1.27 Moz
silver. The 2022 drill program is building on these exceptional
results with a focus on delivering 1 Moz in the short-term at WKP
in support of the up-coming pre-feasibility study."
"Our Reserves and Resources continue to provide a strong
foundation for the Company as we steadily increase our gold
production over the next three years. The underground
potential at Haile is growing with the introduction of the Palomino
Indicated Resource and our investment in both exploration and
resource conversion drilling. Once we develop the underground
infrastructure at Horseshoe we will also have further opportunity
to convert resources."
RESERVES
As of 31 December 2021,
OceanaGold's Proven and Probable ("P&P") Reserves stood at
131 Mt at 1.33 g/t gold for 5.63 Moz
of gold, including 8.02 Moz of silver and 0.15 Mt of copper,
representing a 0.43 Moz decrease in gold Reserves year-on-year
(see Table 1) largely due to mining depletion.
Table 1: Updated Mineral Reserves (as of 31 December 2021)
- Mineral Reserves constrained to mine designs based upon
US$1,500/oz gold, US$3.00/lb copper and US$17/oz silver. New
Zealand reserves use 0.71
NZD/USD exchange rate.
- Reported estimates of contained metal are not depleted for
processing losses. For underground reserves, cut-offs applied to
diluted grades.
- For Macraes: Frasers Underground cut-off is 1.61 g/t Au while
Golden Point Underground cut-off is 1.44 g/t Au.
- For Waihi Underground, the cut-off for previously unmined
stoping areas is 2.2 g/t Au, increasing to 2.9 g/t Au for stoping
areas in close proximity to remnant workings.
- For Didipio: old equivalence is based upon the presented gold
and copper prices as well as processing recoveries. Gold Equivalent
(AuEq) = Au g/t + 1.37 x Cu%. The 22.2 Mt open pit stockpile
inventory includes 5.3 Mt of low-grade stocks mined at an
approximate 0.27 g/t AuEq cut-off. The UG, incremental stopes
proximal to development already planned to access main stoping
areas are reported to a lower cut-off of 0.76 g/t AuEq.
- For Haile: Open Pit, the primary cut-off grade is 0.5 g/t Au
while oxide material is assigned a 0.6 g/t Au cut-off grade.
Horseshoe Underground, the cut-off is 1.53 g/t Au, with adjacent
lower grade stopes included in the reserves based on an incremental
stope cut-off grade of 1.37 g/t Au.
Figure 1: Changes to Proven & Probable Mineral
Reserves
Note: "Depletions"
refer to 2021 mining depletion, "Reserve Model Updates" represent
drilling-related changes to reserve changes (growth or reductions)
or initial reserve declarations, "Economic Factors" relate to
mining cost and cut-off grade changes, "Adjustments" relate to
changes in mining method assumptions (e.g. open pit versus
underground).
|
RESOURCES
As of 31 December 2021,
OceanaGold's Measured and Indicated ("M&I") Resources stood at
199 Mt at 1.43 g/t gold for 9.13 Moz of gold, including 14 Moz of
silver and 0.17 Mt of copper (Table 2). Mineral Resources are
reported inclusive of Mineral Reserves.
Table 2: Updated Mineral Resources – Measured and
Indicated (as of 31 December
2021)
- Mineral Resources include Mineral Reserves. There is no
certainty that Mineral Resources, not included as Mineral Reserves,
will convert to Mineral Reserves. All resources based upon
US$1,700/oz gold, US$3.50/lb copper and US$17/oz silver and a 0.71
NZD/USD exchange rate for New
Zealand resources.
- Open pit resources constrained to shells based upon economic
assumptions above. Waihi open pit resources reported within a pit
design limited by infrastructural considerations. Underground
resources for Didipio, Horseshoe at Haile, and Frasers and
Golden Point at Macraes, are
reported within volumes guided by optimised stope designs.
Underground resources for Palomino at Haile and Martha and WKP at
Waihi are reported within optimised stope designs based upon
economic assumptions above.
- For Macraes: Frasers Underground at a 1.25 g/t Au cut-off and
Golden Point Underground at a 1.34 g/t Au cut-off.
- For Waihi: Martha Underground at a 2.15 g/t Au cut-off, WKP at
a 2.5 g/t Au cut-off, Martha open pit at a 0.5 g/t Au cut-off and
Gladstone open pit at a 0.56 g/t
Au cut-off. Martha Underground M&I Resources 5.8 Mt at 5.93 g/t
Au for 1.11 Moz. WKP M&I resources 1.5 Mt at 13.5 g/t Au for
0.64 Moz.
- For Didipio open pit, only stockpiles remain. These include 5.3
Mt of low grade at 0.27 g/t AuEq. Underground resources reported
between the 2,460mRL and 1,980mRL with AuEq cut-off based on
presented gold and copper prices. AuEq = Au g/t + 1.39 x Cu %.
- For Haile OP primary cut-off 0.45 g/t Au, oxide cut-off 0.55
g/t Au. Palomino Resources at a 1.39 g/t Au cut-off and Horseshoe
Resources at a 1.35 g/t Au cut-off, the difference due to slightly
lower metallurgical recovery at Palomino.
On a consolidated basis, OceanaGold's M&I Resources
decreased by 0.92 Moz (Figure 2). Decreases were mainly due to
mining depletion across the Company's operations as well as the
reduction in the reportable Round Hill Open Pit Resource at Macraes
following the completion of an internal prefeasibility-level study
(see section on Macraes). The decreases were partially offset by
gains due to resource conversion drilling-related resource updates
for Palomino at Haile, WKP and Martha at Waihi, and Golden Point at Macraes.
Figure 2: Changes to Measured & Indicated Mineral
Resources
Note: "Depletions"
refer to 2021 mining depletion, "Resource Model Updates" represent
drilling-related resource changes (growth or reductions) or initial
resource declarations, "Economic Factors" relate to mining cost and
cut-off grade changes, "Adjustments" relate to changes in mining
method assumptions (e.g. open pit versus underground).
|
As of 31 December 2021, OceanaGold's
Inferred Resources stood at 62 Mt at 1.9 g/t gold for 3.9 Moz of
gold, including 7.5 Moz of silver and 0.04 Mt of copper (Table 3).
Year on year this represents a 0.5 Moz decrease mainly due to the
conversion of Inferred Resources at Waihi, Macraes and Haile.
Table 3: Updated Mineral Resources –
Inferred Resource Statement (as of 31
December 2021)
See footnotes for Table
2.
|
Figure 3: Changes to Inferred Resources
NEW ZEALAND
Waihi
Underground P&P Reserves at Waihi stood at 4.77 Mt at 4.2
g/t gold for 0.64 Moz gold including 2.23 Moz silver with reserve
growth at Martha offsetting mining depletion (Figure 4). No open
pit reserves are reported.
Figure 4: Changes to Waihi Proven & Probable Mineral
Reserves
The Waihi underground M&I Resources stood at 7.3 Mt at 7.45
g/t gold for 1.76 Moz gold, including 4.99 Moz silver and open pit
M&I Resources stood at 6.6 Mt at 1.86 g/t gold for 0.40 Moz
gold, including 2.89 Moz silver (Figure 5). Combined
underground and open pit M&I Resources totalled 13.9 Mt at 4.81
g/t gold for 2.15 Moz gold, including 7.87 Moz silver, representing
a year-on-year increase of 0.31 Moz due to the conversion of
Inferred Resources at WKP and Martha, respectively:
- Martha Indicated Resources 5.8 Mt at 5.93 g/t gold for 1.11 Moz
gold including 3.71 Moz silver.
- Martha Inferred Resources 2.9 Mt at 5.1 g/t gold for 0.47 Moz
gold including 2.0 Moz silver.
- WKP Indicated Resources 1.5 Mt at 13.5 g/t gold for 0.64 Moz
gold including 1.27 Moz silver.
- WKP Inferred Resources of 2.3 Mt at 9.4 g/t gold for 0.7 Moz
gold including 1.6 Moz silver.
Figure 5: Changes to Waihi Measured & Indicated
Mineral Resources
Underground Resources at Waihi
During 2022, the Company expects to drill 21,235 metres at
Martha Underground ("MUG") with a focus on resource conversion
(11,875 metres) and resource extension (9,360 metres). This
programme is designed to improve resource confidence and to test
opportunities proximal to mine design.
WKP is located in the upper North Island of New Zealand, approximately 10 kilometers north
of the Martha Underground and existing Waihi facilities. WKP is a
rhyolite-hosted, low sulphidation epithermal quartz vein system.
The rhyolites have undergone pervasive hydrothermal alteration,
often with complete replacement by quartz and adularia with minor
illite and/or smectite clay. Gold mineralisation occurs in
association with quartz veining developed along two types of
structurally controlled vein arrays. The principal veins occupy
laterally continuous, NE trending (025-47°), moderately dipping
(60-65°) district-scale graben step faults, reaching up to 10
metres in width. Subsidiary, extensional veins (1-100 centimetres
wide) are developed between or adjacent to the principal fault
hosted veins.
The Company expects to drill 16,775 metres at WKP primarily on
resource conversion in 2022 to increase the Indicated Resources in
support of the prefeasibility study scheduled for release in
2023.
The Waihi Inferred Resources stood at 1.5 Moz gold, a small
decrease year on year (Figure 6). The Inferred Resources at Waihi
present a significant opportunity for future conversion.
Figure 6: Changes to Waihi Inferred Resources
Resource Model Performance
Table 4 summarizes the Waihi underground resource model
reconciliations for 2018 to 2021. Reserve modifying factors have
been applied for ore loss and dilution. The resource model to
mill-adjusted mine reconciliation data from various ore sources for
the four years to 2021 show variable performance from year to year
with a reasonable long-term average performance; +8% for tonnes,
-2% for grade and +7% for contained gold.
Table 4: Waihi Underground Model to
Mill-Adjusted Mine Reconciliation
Year
|
Resource Model
(1), (2)
|
Mine
(Mill-Reconciled)
|
Reconciliation
Ratios
|
Mt
|
grade
|
Moz
|
Mt
|
grade
|
Moz
|
Mt
|
grade
|
Moz
|
2021(3)
|
0.22
|
4.19
|
0.030
|
0.29
|
3.24
|
0.030
|
1.31
|
0.77
|
1.01
|
2020
|
0.13
|
5.80
|
0.024
|
0.13
|
5.30
|
0.022
|
1.01
|
0.91
|
0.92
|
2019
|
0.43
|
5.52
|
0.077
|
0.43
|
5.60
|
0.078
|
1.00
|
1.01
|
1.01
|
2018
|
0.40
|
6.20
|
0.08
|
0.43
|
6.80
|
0.095
|
1.07
|
1.10
|
1.18
|
Total
|
1.19
|
5.53
|
0.211
|
1.29
|
5.44
|
0.225
|
1.08
|
0.98
|
1.07
|
|
|
|
|
|
|
|
|
|
|
|
1.
|
Underground models
include reserve modifying factors for ore loss and
dilution
|
2.
|
Current resource models
used
|
3.
|
2021 mining included
Inferred Resources of 0.063 Mt at 3.23 g/t for 7 koz. These
Inferred Resources are not included in the reconciliation as they
are not considered to have sufficient geological confidence for
detailed mine planning.
|
Mining during 2018, 2019 and 2020 was largely on the Correnso
vein for which reconciliation was in line with expectations. The
reconciliation for 2021 largely represents mining at MUG and shows
greater variance. However, the mined MUG tonnage to-date is not
considered to be large or geologically representative, reflecting
less than 5% of the total MUG reserve. The majority of ore mined at
MUG to-date has been development ore rather than stoping ore, and
with limited grade control coverage. That said, the greater
variance in reconciliation performance is in areas with higher
geological and grade complexity, particularly in the smaller,
subsidiary veins. The modelling and classification of these veins
is under review and will continue as mining progresses in 2022.
Macraes
The P&P Reserves for Macraes stood at 39.0 Mt at 0.95 g/t
gold for 1.20 Moz gold with 0.98 Moz in the open pits and 0.22 Moz
in the Frasers and Golden Point Underground mines. Year-on-year
drilling-related underground reserve growth at Golden Point
Underground and within the open pits has partially offset 2021
mining depletion for a net 0.1 Moz decrease.
Figure 7: Changes to Macraes Proven & Probable Mineral
Reserves
The Macraes M&I Resources stood at 84.6 Mt at 0.93 g/t gold
for 2.52 Moz of gold, including 6.9 Mt at 2.53 g/t gold for 0.56
Moz of gold for the Frasers Underground and Golden Point
Underground mines. The year-on-year net decrease in M&I
Resources of 1.08 Moz is largely due to a 0.95 Moz reduction for
the Round Hill Open Pit Resource, Macraes Open Pit and underground
mining depletion as well as write-downs at Frasers Underground
where development retreat has reduced the prospects of future
resource extraction (see Adjustments in Figure 8).
The reduction of the Round Hill Open Pit Resource followed the
completion of an internal study assessing a larger Round Hill Open
Pit. Earlier, less detailed studies had provided positive outcomes
for the relocation of the processing plant and Mixed Tailings
Impoundment ("MTI"), both required to develop the larger Round Hill
Open Pit. The financial analysis for the more recent and
detailed study however, returned a negative NPV outcome due to
additional capital requirements of moving the processing plant. On
this basis and current assumptions, reasonable prospects of
eventual economic extraction could no longer be maintained for the
portion of the pit that required relocation of the plant and MTI.
The Round Hill Open Pit M&I Resource decreased from 54 Mt at
0.92 g/t gold for 1.61 Moz to 21 Mt at 0.97 g/t gold for 0.66
Moz.
Figure 8: Changes to Macraes Measured &
Indicated Mineral Resources
Macraes Inferred Resources stood at 24 Mt at 0.7 g/t gold for
0.6 Moz of gold, a decrease of 0.2 Moz from the previous year, due
mainly to the conversion of Inferred Resources to the Indicated
category and, to a lesser extent, mining depletion (Figure 9).
Figure 9: Changes to Macraes Inferred Resources
Reserve Model Performance
Table 5 summarizes the combined open pit and underground
resource model reconciliations for 2018 to 2021.
The reserve model to mill-adjusted mine reconciliation data for
the four years to 2021 show variable performance from year to year,
albeit the long-term average performance for this period has been
reasonable; +9% for tonnes, -3% for grade and +6% for contained
gold. While the long-term performance has been reasonable, the
grade performance for 2020 and 2021 was less than 2018 and 2019,
although the contained gold reconciliation has been positive. The
causes for the recent grade performance have been a combination of
complex mineralization styles, the realization of additional
low-grade mineralization in grade control, difficulty in achieving
representative drilling coverage at Gay Tan Open Pit due to limited
drill rig access, and in 2021, near-surface depletion at Deepdell
Open Pit. While geological complexity remains in 2022, resource
model performance is expected to return to long term performance.
While annual reconciliation fluctuations are expected to continue,
the resource estimates are believed to provide an acceptable basis
for medium to long term mine planning purposes.
Table 5: Combined Open Pit and
Underground Model to Mill-Adjusted Mine Reconciliation
Year
|
Reserve
Model
|
Mill-Adjusted
Mine
|
Reconciliation
Ratios
|
|
Mt
|
grade
|
Moz
|
Mt
|
grade
|
Moz
|
tonnes
|
grade
|
oz
|
2021
|
4.11
|
1.06
|
0.14
|
4.78
|
0.97
|
0.15
|
1.16
|
0.91
|
1.06
|
2020
|
3.74
|
1.15
|
0.14
|
4.71
|
1.04
|
0.16
|
1.26
|
0.91
|
1.14
|
2019
|
4.34
|
1.23
|
0.17
|
4.80
|
1.18
|
0.18
|
1.11
|
0.96
|
1.07
|
2018
|
6.17
|
1.21
|
0.24
|
5.79
|
1.30
|
0.24
|
0.94
|
1.07
|
1.00
|
Total
|
18.4
|
1.17
|
0.69
|
20.1
|
1.13
|
0.73
|
1.09
|
0.97
|
1.06
|
|
|
|
|
|
|
|
|
|
|
|
- Open pit resource models implicitly include mining selectivity.
Underground models include reserve modifying factors for ore loss
and dilution.
- Current resource model used.
Blackwater
Resources for the Blackwater Project remain on the Company's
inventory and are unchanged from the 31
December 2020 reported resources.
UNITED STATES OF
AMERICA
Haile
P&P Reserves totalled 45.4 Mt at 1.75 g/t gold for 2.55 Moz
of gold including 3.23 Moz of silver. Of the 2.55 Moz, the Haile
Underground contributes 0.42 Moz. Year on year P&P Reserves
have decreased 0.29 Moz due to a combination of mining depletion
and increased mining costs (Figure 10).
Figure 10: Changes to Haile Proven & Probable
Mineral Reserves
As announced on 9 February 2022,
OceanaGold completed an internal technical review of the Haile mine
during 2021. An outcome of this technical review was an
adjustment to the reserve cut-off grade in line with revised cost
estimates for mining, processing, and general and administration
costs. This has resulted in a reduction in P&P Reserves of
approximately 0.12 Moz as shown in Figure 11.
Total Haile M&I Resources stood at 52.9 Mt at 1.79 g/t gold
for 3.04 Moz of gold, including 3.61 Moz of silver. Of the 3.04 Moz
of gold, the Haile underground contributes 0.73 Moz which includes
the first-time reporting of Indicated Resources for the Palomino
Underground deposit; 2.3 Mt at 2.79 g/t gold for 0.20 Moz of gold.
Year on year M&I Resources decreased by 0.14 Moz due the
combination of mining depletion and a small decrease in the
resource reporting shell due to revised costs as noted above
(Figure 11). Resource growth at Palomino partially offset
these decreases.
Figure 11: Changes to Haile Measured & Indicated
Mineral Resources
Inferred Resources stood at 11 Mt at 2.0 g/t gold for 0.7 Moz
gold. Year-on-year the Inferred Resources decreased 0.4 Moz largely
due to infill drilling-related conversion to Indicated Resources
(Figure 12).
Figure 12: Changes to Haile Inferred
Resources
Palomino Underground Deposit
Palomino is a gold deposit located approximately 650 metres
southwest of the Horseshoe deposit and 300 metres below surface
(Figure 13).
Figure 13: Long-Section looking NNW, showing Palomino
Mineralization Relative to Horseshoe, HEX and, entire Haile
drilling intercept dataset (colored by Au g/t)
The deposit dimensions are approximately 400 metres long x 70
metres high x 90 metres wide. Lozenge-shaped mineralized zones
strike ENE, dip NW and plunge gently NE. Diamond drillhole spacing
ranges from 20 to 70 metres. Fine-grained gold is hosted in pyritic
and silicified siltstone and intrusive rocks along a steeply
SE-dipping, ENE-striking contact with barren dacite flows.
Mineralization is truncated by several NNW-striking, sub-vertical,
1 to 25 metres thick diabase dikes.
The resources are reported within a Mine Stope Optimised volume
using a US$1,700 per oz gold price.
Due to the diffuse grade boundaries, material not classified as
Inferred or Indicated Resource is included as dilution at zero
grade. Indicated Resources are currently estimated at 2.3 Mt at
2.79 g/t gold for 0.20 Moz of gold. Inferred Resources of 3.6 Mt at
2.3 g/t gold for 0.26 Moz remain to be converted.
Reserve Model Performance
Table 6 summarizes the open pit resource model reconciliations
2018 to 2021. The resource model to mill-adjusted mine
reconciliation data for the four years to 2021 show variable
performance from year to year albeit the long-term average
performance for this period shows +12% for tonnes, -4% for grade
and +8% for contained gold. Note that the four-year aggregated
grade reconciliation is negatively skewed by low mining selectivity
during 2020 which resulted in excessive mining dilution during that
year. More selective mining practices re-introduced during 2021
have resolved this.
While annual reconciliation fluctuations are expected to
continue, the open pit resource estimates are believed to provide
an acceptable basis for medium to long term mine planning
purposes.
Table 6: Open Pit Model to Mill-Adjusted Mine
Reconciliation
Year
|
Reserve
Model
|
Mine
(Mill-Reconciled)
|
Reconciliation
Ratios
|
Mt
|
grade
|
Moz
|
Mt
|
grade
|
Moz
|
Tonnes
|
Grade
|
Au
Oz
|
2021
|
3.16
|
1.98
|
0.20
|
3.27
|
2.17
|
0.23
|
1.04
|
1.09
|
1.13
|
2020
|
2.57
|
2.08
|
0.17
|
3.33
|
1.59
|
0.17
|
1.30
|
0.76
|
0.99
|
2019
|
2.87
|
1.96
|
0.18
|
3.18
|
1.78
|
0.18
|
1.11
|
0.91
|
1.01
|
2018
|
2.85
|
1.67
|
0.15
|
2.57
|
1.93
|
0.16
|
0.90
|
1.16
|
1.04
|
Total
|
11.0
|
1.94
|
0.69
|
12.4
|
1.86
|
0.74
|
1.12
|
0.96
|
1.08
|
- Open pit resource models implicitly include mining
selectivity.
- Current resource model used.
PHILIPPINES
Didipio
Didipio P&P Reserves stood at 42.2 Mt at 0.91 g/t gold for
1.23 Moz of gold, including 2.57 Moz of silver and 0.15 Mt of
copper, a year-on-year decrease due to 2021 mining depletion
(Figure 14) as the production ramp-up continues to progress ahead
of schedule. A small decrease is noted in Adjustments due to
exclusion of sub-economic low-grade material at the tail end of the
life of mine schedule.
Figure 14: Changes to Didipio Proven & Probable
Mineral Reserves
Didipio M&I Resources stood at 47.8 Mt at 0.92 g/t gold for
1.41 Moz of gold, including 2.88 Moz of silver and 0.17 Mt of
copper, a small year-on-year decrease due to 2021 mining depletion
(Figure 15), as the production ramp-up continues to progress ahead
of schedule. Surface stockpiles include medium and low-grade
stocks. 17.6 Mt at 0.38 g/t gold and 0.34% copper remains from open
pit mining during 2012 to 2017 (mined to a 0.4 g/t AuEq cut-off)
and an additional 5.3 Mt at 0.18 g/t gold and 0.15% copper (mined
to a 0.27 g/t AuEq cut-off).
Figure 15: Changes to Didipio Measured &
Indicated Mineral Resources
Inferred Resources stood at 0.4 Moz of gold, 0.6 Moz of silver
and 0.04 Mt of copper, no change year-on-year.
Reserve Model Performance
The reconciliation in Table includes mining from
May 2018 to December 2021 covering the period of ramp up for
underground mining. The mill feed for this period included
rehandled open pit stockpiles, underground development and stope
ore. Mining of a crown pillar at the base of the open pit
to allow geotechnical strengthening with cement commenced in 2021
and provided the main source of 2021 mill feed. Grade control
sampling of the crown pillar was sub-optimal because the focus was
on geotechnical strengthening rather than ore extraction. When this
mill feed source is exhausted in early 2022, the reconciliation is
expected to improve.
Table 7: Combined Open Pit and
Underground Model to Mill-Adjusted Mine Reconciliation
Year
|
Reserve
Estimate
|
Mill
|
Reconciliation
Ratios
|
Mt
|
Au
g/t
|
Cu
%
|
Au
Moz
|
Cu
Mt
|
Mt
|
Au
g/t
|
Cu
%
|
Au
Moz
|
Cu
Mt
|
Mt
|
Au
g/t
|
Cu
%
|
Au
Moz
|
Cu
Mt
|
2021
|
0.64
|
1.07
|
0.38
|
0.02
|
0.002
|
0.63
|
0.92
|
0.43
|
0.02
|
0.003
|
0.98
|
0.86
|
1.12
|
0.84
|
1.10
|
2020
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
|
|
|
|
2019
|
2.23
|
1.26
|
0.44
|
0.09
|
0.010
|
2.33
|
1.21
|
0.44
|
0.09
|
0.010
|
1.04
|
0.96
|
1.00
|
1.00
|
1.05
|
2018
|
2.27
|
1.16
|
0.49
|
0.08
|
0.011
|
2.22
|
1.26
|
0.49
|
0.09
|
0.011
|
0.98
|
1.09
|
0.99
|
1.07
|
0.97
|
Total
|
5.15
|
1.19
|
0.46
|
0.20
|
0.023
|
5.19
|
1.19
|
0.46
|
0.20
|
0.024
|
1.01
|
1.00
|
1.01
|
1.01
|
1.02
|
- Underground models include reserve modifying factors for ore
loss and dilution.
- 2018 only includes May to December to reflect the ramp up into
underground mining.
- Open pit feed = rehandled medium grade stockpiles.
- Current resource model used.
OTHER
OceanaGold's interest in the Sam's Creek project in New Zealand is 18.47%.
Table 8: Updated Mineral Resources, Sam's Creek – Minority
Interest in Assets (as of 31 December
2021)
- OceanaGold has a 18.47% interest in the Sam's Creek Project.
Reported at a 0.7 g/t Au cut-off and factored by the percentage
ownership.
FILING OF TECHNICAL REPORTS
The company will lodge updated NI 43-101 Technical reports for
both Didipio and Haile on 31 March
2022 to provide technical updates for both projects.
In line with the requirements of the listing rules of the
Australian Stock Exchange ("ASX"), the Company has separately filed
material summaries and JORC Table 1 information related to the
Resource and Reserves with the ASX. These can be found at
www.asx.com.au, and is also available on the Company's website at
https://oceanagold.com/investor-centre/tsx-and-asx-announcements/.
Authorised for release to market by OceanaGold Corporate Company
Secretary, Liang Tang.
www.oceanagold.com | Twitter: @OceanaGold
About OceanaGold
OceanaGold is a multinational gold producer committed to the
highest standards of technical, environmental, and social
performance. For 31 years, we have been contributing to excellence
in our industry by delivering sustainable environmental and social
outcomes for our communities, and strong returns for our
shareholders. Our global exploration, development, and operating
experience has created an industry-leading pipeline of organic
growth opportunities and a portfolio of established operating
assets including Didipio Mine in the
Philippines; Macraes and Waihi operations in New Zealand; and Haile Gold Mine in
the United States of America.
Technical Disclosure
General
All Mineral Reserves and Mineral Resources were calculated as of
31 December 2021 and have been
calculated and prepared in accordance with the standards set out in
the Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves dated December
2012 (the "JORC Code") and in accordance with National
Instrument 43-101 of the Canadian Securities Administrators ("NI
43-101"). The JORC Code is the accepted reporting standard for the
Australian Stock Exchange Limited ("ASX").
The definitions of Ore Reserves and Mineral Resources as set
forth in the JORC Code have been reconciled to the definitions set
forth in the CIM Definition Standards. If the Mineral Reserves and
Mineral Resources were estimated in accordance with the definitions
in the JORC Code, there would be no substantive difference in such
Mineral Reserves and Mineral Resources.
Competent / Qualified Persons
Macraes: Any updates of Mineral Resources for Macraes
open pits have been verified and approved by J. Moore while the
updates of Mineral Resources for Macraes underground operations
have been verified and approved by M. Grant. Mineral Reserves for
Macraes open pits have been verified and approved by, or are based
on information prepared by, or under the supervision of, P Doelman.
The Mineral Reserves for Macraes underground have been verified and
approved by or are based upon information prepared by, or under the
supervision of, S. Mazza.
Blackwater: Any updates of Mineral Resources for
Blackwater have been verified and approved by J. Moore.
Waihi: Any updates of Mineral Resources for Waihi's
Martha open pit and Wharekirauponga Underground have been verified
and approved by, or are based on information prepared by, or under
the supervision of, J. Moore. Any updates of Mineral Resources for
Waihi's Gladstone open pit and
Martha Underground have been verified and approved by, or are based
on information prepared by, or under the supervision of, L.
Crawford-Flett. The Mineral Reserves for Waihi have been verified
and approved by, or are based on information prepared by, or under
the supervision of D. Townsend for
underground.
Haile: The updates of Mineral Resources for Haile open
pit and underground have been verified and approved by, or are
based on information prepared by, or under the supervision of, J.
G. Moore. The updates of Mineral Reserves for Haile open pits have
been verified and approved by, or are based on information prepared
by, or under the supervision of, G. Hollett and the Mineral
Reserves for Haile underground have been verified and approved by
or are based upon information prepared by, or under the supervision
B. Drury.
Didipio: The Mineral Resources for Didipio have been
verified and approved by, or are based on information prepared by,
or under the supervision of, J. Moore while the Mineral Reserves
for Didipio underground have been verified and approved by or are
based upon information prepared by, or under the supervision P.
Jones.
Messrs Crawford-Flett, Doelman, Grant and Townsend are full-time employees of the
Company's subsidiary, Oceana Gold
(New Zealand) Limited. Messrs
Hollett, Jones, Mazza and Moore are full-time employees of the
Company's subsidiary, OceanaGold Management Pty Limited. Ms Drury
is a full-time employee of the Company's subsidiary, Haile Gold
Mine, Inc.
Mr Hollett is a Professional Engineer registered with Engineers
and Geoscientists of British
Columbia. Messrs Doelman, Jones, Mazza, Moore and
Townsend are Members and Chartered
Professionals with the Australasian Institute of Mining and
Metallurgy. Mr Grant is a member of the Australian
Institute of Geologists. Ms Drury is a Registered Member with
the Society of Mining, Metallurgy & Exploration.
All such persons are "qualified persons" for the purposes of NI
43-101 and have sufficient experience relevant to the style of
mineralisation and type of deposit under consideration and to the
activity which they are undertaking to qualify as a "competent
person" as defined in the JORC Code.
Ms Drury and Messrs Crawford-Flett, Doelman, Grant, Hollett,
Jones, Mazza, Moore, and Townsend
consent to inclusion in this public release of the matters based on
their information in the form and context in which it appears. The
estimates of Mineral Resources and Mineral Reserves contained in
this public release are based on, and fairly represent, information
and supporting documentation prepared by the named qualified and
competent persons in the form and context in which it appears.
Technical Reports
For further scientific and technical information supporting the
disclosure in this media release (including disclosure regarding
Mineral Resources and Mineral Reserves, data verification, key
assumptions, parameters, and methods used to estimate the Mineral
Resources and Mineral Reserves, and risk and other factors)
relating to the Didipio Gold-Copper Mine, the Macraes Mine, the
Haile Gold Mine, the Waihi Gold Mine and the Blackwater project,
please refer to the following NI 43-101 compliant technical reports
and the Blackwater Preliminary Economic Assessment released on
21 October 2014, available at
www.sedar.com under the Company's name:
a)
|
"NI 43-101 Technical
Report, Macraes Gold Mine, Otago, New Zealand" dated October 14,
2020, prepared by D. Carr, Chief Metallurgist, of OceanaGold
Management Pty Limited, T. Cooney, previously General Manager of
Studies of OceanaGold Management Pty Limited, P. Doelman, Tech
Services and Project Manager, S. Doyle, Principal Resource
Geologist and P. Edwards, Senior Project Geologist, each of
OceanaGold (New Zealand) Limited;
|
b)
|
"Technical Report for
the Reefton Project located in the Province of Westland, New
Zealand" dated May 24, 2013, prepared by K. Madambi, previously
Technical Services Manager of Oceana Gold (New Zealand) Limited and
J. Moore, Chief Geologist, of Oceana Gold Management Pty
Limited;
|
c)
|
"Technical Report for
the Didipio Gold / Copper Operation Luzon Island" dated March 31,
2022, prepared by D. Carr, Chief Metallurgist, P. Jones, Group
Engineer and J. Moore, Chief Geologist, each of Oceana Gold
Management Pty Limited;
|
d)
|
Waihi District Study -
Martha Underground Feasibility Study NI 43-101 Technical Report"
dated March 31, 2021, prepared by T. Maton, Study Manager and P.
Church, Principal Resource Development Geologist, both of Oceana
Gold (New Zealand) Limited, and D. Carr, Chief Metallurgist, of
OceanaGold Management Pty Limited; and
|
e)
|
"NI 43-101 Technical
Report Haile Gold Mine Lancaster County, South Carolina" dated
March 31, 2022, prepared by D. Carr, Chief Metallurgist, G.
Hollett, Group Mining Engineer, and J. Moore, Chief Geologist, each
of OceanaGold Management Pty Limited, Michael Kirby of Haile Gold
Mine, Inc., J. Poeck, M. Sullivan, D. Bird, B. S. Prosser and J.
Tinucci of SRK Consulting, J. Newton Janney-Moore and W. Kingston
of Newfields and L. Standridge of Call and Nicholas.
|
Cautionary Note Regarding Mineral Resources and Mineral
Reserves
The Company's disclosure of Mineral Reserve and Mineral Resource
information is governed by NI 43-101 under the guidelines set out
in the Canadian Institute of Mining, Metallurgy and Petroleum (the
"CIM") Standards on Mineral Resources and Mineral Reserves, adopted
by the CIM Council, as may be amended from time to time by the CIM
("CIM Standards"). The disclosure of Mineral Reserve and Mineral
Resource information for properties held by the Company is based on
the reporting requirements of the JORC Code. CIM definitions of the
terms "Mineral Reserve", "Proven Mineral Reserve", "Probable
Mineral Reserve", "Mineral Resource", "Measured Mineral Resource",
"Indicated Mineral Resource" and "Inferred Mineral Resource", are
substantially similar to the JORC Code corresponding definitions of
the terms "Ore Reserve", "Proved Ore Reserve", "Probable Ore
Reserve", "Mineral Resource", "Measured Mineral Resource",
"Indicated Mineral Resource" and "Inferred Mineral Resource",
respectively. Estimates of Mineral Resources and Mineral Reserves
prepared in accordance with the JORC Code would not be materially
different if prepared in accordance with the CIM definitions
applicable under NI 43-101.
There can be no assurance that those portions of such Mineral
Resources that are not Mineral Reserves will ultimately be
converted into Mineral Reserves. Mineral Resources are not Mineral
Reserves and do not have demonstrated economic viability. All
Mineral Reserves are within the Mineral Resource.
Cautionary Statement for Public Release
Certain information contained in this public release may be
deemed "forward-looking" within the meaning of applicable
securities laws. Forward-looking statements and information relate
to future performance and reflect the Company's expectations
regarding the generation of free cash flow, execution of business
strategy, future growth, future production, estimated costs,
results of operations, business prospects and opportunities of
OceanaGold Corporation and its related subsidiaries. Any statements
that express or involve discussions with respect to predictions,
expectations, beliefs, plans, projections, objectives, assumptions
or future events or performance (often, but not always, using words
or phrases such as "expects" or "does not expect", "is expected",
"anticipates" or "does not anticipate", "plans", "estimates" or
"intends", or stating that certain actions, events or results
"may", "could", "would", "might" or "will" be taken, occur or be
achieved) are not statements of historical fact and may be
forward-looking statements. Forward-looking statements are subject
to a variety of risks and uncertainties which could cause actual
events or results to differ materially from those expressed in the
forward-looking statements and information. They include, among
others, the accuracy of Mineral Reserve and resource estimates and
related assumptions, inherent operating risks and those risk
factors identified in the Company's most recent Annual Information
Form prepared and filed with securities regulators which is
available on SEDAR at www.sedar.com under the Company's name. There
are no assurances the Company can fulfil forward-looking statements
and information. Such forward-looking statements and information
are only predictions based on current information available to
management as of the date that such predictions are made; actual
events or results may differ materially as a result of risks facing
the Company, some of which are beyond the Company's control.
Although the Company believes that any forward-looking statements
and information contained in this press release is based on
reasonable assumptions, readers cannot be assured that actual
outcomes or results will be consistent with such statements.
Accordingly, readers should not place undue reliance on
forward-looking statements and information. The Company expressly
disclaims any intention or obligation to update or revise any
forward-looking statements and information, whether as a result of
new information, events or otherwise, except as required by
applicable securities laws. The information contained in this
release is not investment or financial product advice.
SOURCE OceanaGold Corporation