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Table T1. Averaged chemical compositions of samples from Hole 735B as a function of rock type and depth in the drill core.

Rock type

Depth interval (mbsf)

N

SiO2
(wt%)

TiO2 (wt%)

Al2O3 (wt%)

Fe2O3T (wt%)

MnO (wt%)

MgO (wt%)

CaO
(wt%)

Na2O (wt%)

K2O (wt%)

P2O5 (wt%)

%Fe2+

Mg#

Ca#

V (ppm)

Cr (ppm)

Ni (ppm)

Cu (ppm)

Zn (ppm)

Rb (ppm)

Sr (ppm)

Y (ppm)

Zr (ppm)

Nb (ppm)

Felsic

(*)

3

64.06

1.62

18.49

1.80

0.05

1.27

4.93

6.24

1.43

0.11

76

0.60

0.26

41

0

12

13

8

9

133

68

184

19

Oxide gabbro

520-705

5

46.55

2.97

12.24

17.69

0.27

6.06

9.99

3.27

0.10

0.86

67

0.51

0.63

311

6

34

68

131

2

159

63

74

4

800-960

6

47.33

2.84

12.80

14.81

0.22

7.36

11.20

2.86

0.06

0.53

77

0.57

0.69

558

140

98

105

101

<1

141

47

81

2

960-1320

2

48.30

2.31

15.01

13.38

0.21

6.13

10.06

3.40

0.08

1.12

74

0.55

0.62

274

59

69

96

121

1

193

63

84

6

Gabbro

520-705

4

52.21

0.52

16.72

7.40

0.13

7.38

12.13

3.43

0.06

0.02

79

0.72

0.66

196

13

63

36

44

1

193

15

43

1

705-800

2

51.24

0.47

16.37

6.78

0.13

9.03

13.16

2.76

0.03

0.02

89

0.75

0.72

183

198

105

92

44

<1

163

12

33

<1

800-960

7

51.04

0.43

16.38

6.93

0.14

8.97

13.21

2.84

0.03

0.03

86

0.75

0.72

175

145

86

86

42

1

167

13

36

1

960-1320

6

51.75

0.38

16.37

6.45

0.13

8.77

13.15

2.97

0.03

0.01

89

0.75

0.71

179

65

77

75

39

1

176

12

25

1

1320-1503

7

51.55

0.35

17.94

5.16

0.11

8.37

13.52

2.95

0.03

0.01

83

0.79

0.72

152

130

86

70

28

1

187

11

28

<1

Olivine gabbro

520-705

12

51.50

0.44

16.18

7.78

0.14

8.85

11.91

3.13

0.06

0.02

91

0.71

0.68

178

49

78

68

48

<1

172

13

50

2

705-800

11

50.65

0.34

16.46

6.93

0.13

10.16

12.67

2.63

0.02

0.02

90

0.76

0.73

159

179

131

99

43

<1

163

9

26

1

800-960

22

50.74

0.44

15.91

7.10

0.13

10.23

12.71

2.69

0.03

0.03

90

0.75

0.72

163

216

118

70

46

<1

161

12

36

<1

960-1320

40

51.04

0.42

16.37

7.16

0.13

9.41

12.56

2.85

0.03

0.02

88

0.75

0.71

164

93

96

79

44

1

171

10

34

1

1320-1503

18

51.14

0.36

16.99

5.80

0.12

9.29

13.62

2.65

0.02

0.02

88

0.78

0.74

174

171

103

67

35

1

168

11

26

1

Troctolitic gabbro

800-960

2

50.95

0.36

17.29

6.19

0.12

9.26

13.05

2.68

0.08

0.02

93

0.76

0.73

167

256

105

55

38

3

161

12

33

1

1320-1503

3

49.29

0.28

17.90

7.84

0.13

10.70

11.11

2.72

0.02

0.01

87

0.76

0.69

104

188

174

74

47

<1

180

10

25

<1

Troctolite

500-520

4

46.99

0.13

18.21

6.52

0.10

15.52

10.65

1.81

0.06

0.01

95

0.83

0.77

58

606

452

74

43

2

149

6

20

1

Notes: Depth interval cutoffs correspond to the chemical stratigraphy units (see "Geochemistry," p. 16). N = number of samples used to calculate the average. (*) = average of three felsic samples with less than 3% Fe2O3; the mixed felsic/mafic rock samples have been excluded. %Fe2+ = percentage of total iron present as ferrous iron; Mg# = (Mg/Mg+Fe2+) molar, calculated from %Fe2+. Ca# = (Ca/Ca+Na)molar. Concentration units = weight percent for the major element oxides; parts per million for the minor and trace elements. Major element compositions are all normalized to sum = 100%.