95-6-12(a) K-feldspar (J = 0.00866) Total gas age = 14.18 ± 0.37 Ma

step

T

(°C)

⁴⁰Ar/³⁹Ar

³⁷Ar/³⁹Ar

³⁶Ar/³⁹Ar

³⁹Ar

(mol)

S³⁹Ar

(%)

⁴⁰Ar*

(%)

Age ± 1s

(Ma)

1

450

28.63

2.26E-02

8.95E-02

2.19E-14

0.95

7.50

33.3± 2.4

2

500

4.389

1.59E-02

1.24E-02

6.25E-14

3.66

15.9

10.9± 0.2

3

500

1.385

1.41E-02

2.76E-03

4.21E-14

5.49

39.5

8.5± 0.2

4

550

1.589

2.20E-02

2.95E-03

1.17E-13

10.6

43.7

10.8± 0.1

5

550

1.109

3.68E-02

1.48E-03

9.52E-14

14.7

58.6

10.1± 0.1

6

600

1.886

6.09E-02

3.57E-03

9.69E-14

18.9

43.0

12.6± 0.1

7

600

1.138

7.20E-02

1.49E-03

4.84E-14

21.0

59.5

10.6± 0.2

8

650

1.829

5.47E-02

3.33E-03

8.48E-14

24.7

45.0

12.8± 0.1

9

650

1.275

3.75E-02

1.91E-03

6.51E-14

27.5

54.0

10.7± 0.2

10

700

1.378

1.70E-02

2.11E-03

6.16E-14

30.2

52.9

11.4± 0.2

11

700

1.769

1.25E-02

3.51E-03

4.08E-14

31.9

40.1

11.0± 0.3

12

750

1.752

1.62E-02

3.39E-03

3.30E-14

33.4

41.5

11.3± 0.3

13

750

2.110

1.50E-02

4.54E-03

2.80E-14

34.6

35.4

11.6± 0.4

14

800

1.938

3.90E-02

3.89E-03

2.37E-14

35.6

39.5

11.9± 0.5

15

850

1.875

6.14E-02

3.58E-03

6.34E-14

38.4

42.6

12.4± 0.2

16

900

2.010

3.46E-02

4.22E-03

6.88E-14

41.4

36.9

11.5± 0.2

17

950

2.001

3.86E-02

3.96E-03

1.07E-13

46.0

40.4

12.6± 0.1

18

1000

2.068

2.57E-02

4.01E-03

2.10E-13

55.1

41.6

13.4± 0.1

19

1050

2.285

3.83E-02

4.45E-03

2.38E-13

65.4

41.5

14.8± 0.1

20

1100

3.000

3.87E-02

6.37E-03

2.85E-13

77.8

36.6

17.1± 0.2

21

1125

3.388

3.04E-02

7.63E-03

2.20E-13

87.4

32.8

17.3± 0.2

22

1150

3.644

2.32E-02

8.52E-03

1.32E-13

93.1

30.3

17.2± 0.3

23

1175

6.753

3.38E-02

1.90E-02

8.27E-14

96.7

16.4

17.2± 0.4

24

1200

13.15

4.09E-02

4.11E-02

2.66E-14

97.9

7.36

15.0± 0.7

25

1225

8.809

3.78E-02

2.52E-02

1.39E-14

98.5

15.3

20.9± 0.9

26

1250

15.24

3.66E-02

4.83E-02

1.09E-14

98.9

6.19

14.7± 1.3

27

1350

21.50

3.74E-02

6.72E-02

2.43E-14

100

7.48

25.0± 1.7