FF-52-9040 K-feldspar (J = 0.000397) Total gas age = 1.16 ± 4.55 Ma

step

T

(° C)

⁴⁰Ar/³⁹Ar

³⁶Ar/³⁹Ar

³⁹Ar

(mol)

S³⁹Ar

(%)

⁴⁰Ar*

(%)

Age + 1s

(Ma)

1

450

142.3

4.81E-01

9.34E-16

0.0903

0.1

0.08 ± 3.06

2

450

114.8

4.05E-01

3.05E-16

0.120

-4.1

-

3

500

72.59

2.13E-01

1.26E-15

0.242

13.1

6.83 ± 1.05

4

500

58.13

1.87E-01

6.64E-16

0.306

4.7

1.98 ± 1.66

5

550

40.11

1.14E-01

2.28E-15

0.527

16.2

4.69 ± 0.52

6

550

30.98

1.03E-01

1.80E-15

0.701

1.8

0.40 ± 0.64

7

600

24.15

6.76E-02

3.42E-15

1.03

17.1

2.98 ± 0.36

8

600

17.43

5.65E-02

4.55E-15

1.47

4.1

0.51 ± 0.26

9

650

22.26

6.26E-02

5.57E-15

2.01

16.7

2.67 ± 0.32

10

650

23.68

8.01E-02

4.44E-15

2.44

0.0

-

11

700

109.7

3.73E-01

4.70E-15

2.89

-0.4

-

12

700

30.42

1.02E-01

5.21E-15

3.40

0.9

0.19 ± 0.29

13

750

9.466

2.97E-02

9.78E-15

4.34

7.2

0.49 ± 0.18

14

750

8.521

2.69E-02

1.05E-14

5.36

6.6

0.41 ± 0.13

15

800

6.671

1.77E-02

1.34E-14

6.66

21.4

1.03 ± 0.12

16

800

6.433

1.70E-02

1.80E-14

8.40

21.5

0.99 ± 0.07

17

850

5.122

1.21E-02

2.69E-14

11.0

29.8

1.10 ± 0.05

18

900

4.837

1.14E-02

5.91E-14

16.7

29.8

1.03 ± 0.03

19

950

4.223

9.47E-03

3.10E-14

19.7

33.3

1.01 ± 0.06

20

1000

2.861

4.79E-03

3.59E-14

23.2

49.9

1.03 ± 0.03

21

1033

2.534

3.70E-03

4.72E-14

27.7

56.2

1.03 ± 0.03

22

1066

2.510

3.20E-03

9.73E-14

37.2

61.8

1.11 ± 0.01

23

1100

2.386

2.39E-03

9.07E-14

45.9

69.7

1.19 ± 0.01

24

1100

3.131

4.93E-03

4.89E-14

50.7

53.0

1.19 ± 0.02

25

1100

4.845

1.08E-02

6.55E-14

57.0

33.8

1.17 ± 0.03

26

1200

1.911

6.84E-04

3.59E-13

91.7

88.8

1.22 ± 0.01

27

1250

4.552

9.64E-03

5.79E-14

97.2

37.1

1.21 ± 0.04

28

1350

10.94

2.92E-02

2.85E-14

100

21.1

1.66 ± 0.10