Sample No.

Weight

mg

Concentration (ppm)

Pb isotope composition¹

Isotope ratios²

Rho

Pb

U

²⁰⁶Pb/

²⁰⁴Pb

²⁰⁶Pb/

²⁰⁷Pb

²⁰⁶Pb/

²⁰⁸Pb

²⁰⁷Pb/

²³⁵U

²⁰⁶Pb/

²³⁸U

²⁰⁷Pb/

²⁰⁶Pb

Gabbronorite dike at the Kirovogorskoye deposit (1)

1

0.3

58.7

101.4

2080

5.121

9.961

13.595

0.5193

2741

2

0.4

48.3

85.0

1600

5.122

10.302

13.300

0.5111

2726

3

0.3

74.6

142.3

400

4.971

3.161

9.159

0.3888

2566

4 (bd)

0.3

2.2

33.5

124

6.023

3.002

0.392

0.0530

353

Siilinjarvi carbonatites (2)

1 (bd)

1.20

5.8

11.6

1720

5.670

7.319

10.432

0.4386

2550 ± 18

0.73

2

0.50

4.4

8.6

1420

5.483

5.364

10.314

0.4305

2594 ± 60

0.71

3

0.25

4.3

7.0

220

4.308

2.529

9.688

0.3993

2615 ± 60

0.73

4

0.45

1.2

33.6

690

5.124

4.167

1.016

0.0922

2629 ± 30

0.71

Tsaga massif, monzogabbro (3)

1

1.18

282.9

490.7

17680

5.480

5.482

12.292

0.4904

2669

0.92

2

0.92

370.6

595.3

13700

5.480

4.588

12.918

0.5159

2668

0.94

3

0.65

175.8

288.0

16730

5.487

4.787

12.744

0.5092

2667

0.78

Tsaga massif, labradorite (4)

18-1

1.00

105.5

179.0

5030

5.464

5.894

12.575

0.5051

2658

0.88

18-2

0.40

186.0

312.7

14560

5.486

5.937

12.686

0.5111

2666

0.67