Sample No.

Weight (mg)

Concentration (ppm)

Pb isotopic composition*

Isotopic ratios**

D,

Pb

U

²⁰⁶Pb/²⁰⁴Pb

²⁰⁶Pb/²³⁸U

²⁰⁷Pb/²³⁵U

²⁰⁷Pb/²⁰⁶Pb

²⁰⁶Pb/²³⁸U

²⁰⁷Pb/²³⁵U

²⁰⁷Pb/²⁰⁶Pb

1 (bd)

0.024

49.847

75.476

1810.2

0.4713 ± 0.0036

10.6714 ± 0.1002

0.16327 ± 0.00088

2499 ± 19

2499 ± 23

2499 ± 13

0

2 (bd)

0.013

95.988

146.99

1419.2

0.4661 ± 0.0042

10.5196 ± 0.1094

0.16337 ± 0.00088

2467 ± 22

2480 ± 25

2498 ± 14

−1.24