Pebble Project

Reserves and Resources

Cutoff
CuEq %

CuEq%

Metric
Tonnes

Cu
(%)

Au
(g/t)

Mo
(ppm)

Ag
(g/t)

Re
(ppm)

Cu
Blb

Au
Moz

Mo
Blb

Ag
Moz

Re
Kkg

Measured

0.3

0.65

 527,000,000

0.33

0.35

178

1.7

0.32

3.83

5.93

0.21

28.1

167

0.4

0.66

 508,000,000

0.34

0.36

180

1.7

0.32

3.81

5.88

0.20

27.4

163

0.6

0.77

 279,000,000

0.40

0.42

203

1.8

0.36

2.46

3.77

0.12

16.5

100

1.0

1.16

 28,000,000

0.62

0.62

302

2.3

0.52

0.38

0.56

0.02

2.0

14

Indicated

0.3

0.77

 5,929,000,000

0.41

0.34

246

1.7

0.41

53.58

64.81

3.21

316.4

2,443

0.4

0.82

 5,185,000,000

0.45

0.35

261

1.8

0.44

51.42

58.35

2.98

291.7

2,271

0.6

0.99

 3,455,000,000

0.55

0.41

299

2.0

0.51

41.88

45.54

2.27

221.1

1,748

1.0

1.29

 1,412,000,000

0.77

0.51

343

2.4

0.60

23.96

23.15

1.07

109.9

853

Measured + Indicated

0.3

0.76

 6,456,000,000

0.40

0.34

240

1.7

0.41

56.92

70.57

3.42

344.6

2,615

0.4

0.81

 5,693,000,000

0.44

0.35

253

1.8

0.43

55.21

64.06

3.18

320.3

2,431

0.6

0.97

 3,734,000,000

0.54

0.41

291

2.0

0.50

44.44

49.22

2.40

237.7

1,848

1.0

1.29

 1,440,000,000

0.76

0.51

342

2.4

0.60

24.12

23.61

1.08

112.0

867

Inferred

0.3

0.55

 4,454,000,000

0.25

0.25

226

1.2

0.36

24.54

35.80

2.22

170.4

1,603

0.4

0.68

 2,646,000,000

0.33

0.30

269

1.4

0.44

19.24

25.52

1.57

119.1

1,154

0.6

0.89

 1,314,000,000

0.48

0.37

292

1.8

0.51

13.90

15.63

0.85

75.6

673

1.0

1.20

 361,000,000

0.68

0.45

377

2.3

0.69

5.41

5.22

0.30

26.3

251

Notes:

David Gaunt, P.Geo., a qualified person as defined under 43-101 who is not independent of Northern Dynasty, is responsible for the August 2020 mineral resource estimate.

Copper equivalent (CuEQ) calculations use metal prices: US$1.85/lb for Cu, US$902/oz for Au and US$12.50/lb for Mo, and recoveries: 85% Cu, 69.6% Au, and 77.8% Mo (Pebble West zone) and 89.3% Cu, 76.8% Au, 83.7% Mo (Pebble East zone).

Contained metal calculations are based on 100% recoveries.

A 0.30% CuEQ cut-off is considered to be appropriate for porphyry deposit open pit mining operations in the Americas.

The mineral resource estimate is constrained by a conceptual pit shell that was developed using a Lerchs-Grossman algorithm and is based in the following parameters: 42 degree pit slope; metal prices and recoveries of US$1,540.00/oz and 61% Au, US$3.63/lb and 91% Cu, US$20.00/oz and 67% Ag and US$12.36/lb and 81% Mo, respectively; a mining cost of US$1.01/ton with a US$0.03/ton/bench increment and other costs (including processing, G&A and transport) of US$6.74/ton.

All mineral resource estimates, cut-offs and metallurgical recoveries are subject to change as a consequence of more detailed analyses that would be required in pre-feasibility and feasibility studies.

 

 

Subscribe to our Email List