Table 2 Gas chemistry of N2-Ar-He and isotope compositions of the Costa Rican springs.

From: Nitrogen recycling at the Costa Rican subduction zone: The role of incoming plate structure

ID

N2/Ar

N2/He

He/Ar

N2exc/He

δ15N-N2

±

R/Ra

±

4He/20Ne

Forearc springs

CR14-01

      

1.02

0.01

0.40

CR12-16

47

8,721

0.005

1,297

−0.7

0.1

   

CR14-02

58

2,195

0.026

676

−2.1

<0.1

0.88

0.01

0.49

CR12-15

66

5,998

0.011

2,377

−1.1

<0.1

   

CR14-03

49

4,267

0.011

773

−0.7

<0.1

0.61

0.01

1.37

CR14-06A

68

3,536

0.019

1,453

−2.8

0.2

0.72

0.01

5.74

CR14-06B

72

2,832

0.025

1,260

     

CR14-07

49

2,647

0.019

493

−1.4

<0.1

0.98

0.01

0.39

CR12-14

75

25,548

0.003

11,865

−0.9

<0.1

   

CR14-08

86

 

0.036

1,291

  

0.62

0.01

0.68

CR14-09

46

1,377

0.034

190

0.0

<0.1

1.06

0.01

0.40

CR14-09B

95

2,230

0.043

1,295

  

1.09

0.12

1.48

CR12-01

51

5,533

0.009

1,221

4.7

0.1

   

CR12-02

73

        

CR12-03

62

2,848

0.022

1,022

4.0

1.6

   

CR12-04

68

785,392

0.0001

320,225

     

Arc front springs

CR12-05

65

4,463

0.015

1,707

−0.5

0.1

   

CR12-06

59

4,980

0.012

1,609

−0.4

0.1

   

CR12-07

143

3,728

0.038

2,687

1.6

<0.1

   

CR12-08

116

4,285

0.027

2,808

−0.4

<0.1

   

CR12-09

109

3,450

0.032

2,188

−0.2

0.1

   

CR12-10

95

4,211

0.022

2,429

0.8

0.1

   

CR12-11

91

3,476

0.026

1,941

−0.4

0.1

   

CR12-12

64

3,618

0.018

1,356

0.1

0.3

   

CR12-13

30

4,722

0.006

 

−0.8

0.1

   

CR12-18

146

13,554

0.011

9,852.996

1.5

<0.1

   

CR12-19

68

84

0.804

34

−4.4

1.5

   

CR14-11

108

1,179

0.092

743

−0.2

<0.1

7.88

0.18

38.81

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