LF-48 K-feldspar (J = 0.000314) Total gas age = 0.93 ± 0.01 Ma

step

T

(° C)

⁴⁰Ar/³⁹Ar

³⁷Ar/³⁹Ar

³⁶Ar/³⁹Ar

³⁹Ar

(mol)

S³⁹Ar

(%)

⁴⁰Ar*

(%)

Age ± 1s

(Ma)

1

450

57.81

7.40E-03

1.59E-01

3.03E-15

0.80

18.8

6.15 ± 0.15

2

500

19.90

6.17E-03

5.23E-02

4.93E-15

2.10

22.3

2.51 ± 0.08

3

550

9.518

4.22E-03

2.59E-02

7.59E-15

4.10

19.6

1.06 ± 0.05

4

625

3.521

3.38E-03

7.76E-03

7.59E-15

6.10

34.8

0.69 ± 0.05

5

850

2.251

3.20E-03

4.93E-03

7.59E-15

8.10

35.1

0.45 ± 0.05

6

700

2.004

3.97E-03

4.36E-03

1.93E-14

13.2

35.4

0.40 ± 0.02

7

775

2.073

3.97E-03

5.04E-03

8.72E-15

15.5

28.0

0.33 ± 0.04

8

925

2.011

3.03E-03

3.77E-03

9.10E-15

17.9

44.4

0.50 ± 0.04

9

1000

2.091

3.30E-03

3.87E-03

1.06E-14

20.7

45.1

0.53 ± 0.03

10

1050

3.059

2.79E-03

5.68E-03

1.67E-14

25.1

45.0

0.78 ± 0.02

11

1080

3.007

2.75E-03

5.27E-03

1.71E-14

29.6

48.1

0.82 ± 0.02

12

1110

2.682

2.47E-03

3.54E-03

4.06E-14

40.3

60.8

0.92 ± 0.01

13

1130

2.269

1.97E-03

2.03E-03

6.26E-14

56.8

73.4

0.94 ± 0.01

14

1150

2.077

1.57E-03

1.30E-03

6.68E-14

74.4

81.3

0.96 ± 0.01

15

1175

2.086

1.42E-03

1.11E-03

7.09E-14

93.1

84.0

0.99 ± 0.01

16

1200

2.287

2.20E-03

1.73E-03

2.28E-14

99.1

77.5

1.00 ± 0.02

17

1250

3.652

8.95E-03

6.53E-03

2.65E-15

99.8

47.1

0.97 ± 0.13

18

1400

19.46

9.33E-03

5.67E-02

7.59E-16

100

13.9

1.53 ± 0.48