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Table 2 Atlantis Bank seafloor samples (N = 937)

From: The Atlantis Bank Gabbro Massif, Southwest Indian Ridge

Lithology

N

%

C-P

Brittle

Oxide %

Metaperidotite

115

43.4

2.3

1.5

    

Plagioclase peridotite

9

3.4

1

0.5

    

Lherzolite

108

40.8

0.7

0.8

    

Harzburgite

10

3.8

1

0.5

    

Talc-soapstone-serpentinite-tremolite schist and breccia

23

8.7

nd

nd

    

Total peridotites

265

28.3

1.4

1.4

    

Olivine websterite

6

0.6

0.8

0.8

    

Dunite

3

0.3

nd

nd

    

Troctolite

1

0.2

0.7

na

    

Olivine gabbro

156

33.9

1.2

1.2

1.2

1.4

  

Gabbro

36

7.8

1.8

1.1

2.2

1.8

  

Gabbronorite

21

4.6

1.6

0.7

0.7

0.4

  

Oxide gabbro

183

39.8

1.8

1.5

0.8

1

6.7

1.5

Metagabbro

41

8.9

2.3

1.3

2.3

1.6

  

Felsic vein/plagiogranite

22

4.8

0.5

0.8

0.6

0.7

  

Total gabbros

460

49.1

      

Aphyric diabase

86

56.2

      

Olivine diabase

5

3.3

      

Plagioclase-olivine diabase

18

11.8

      

Plagioclase diabase

44

28.8

      

Total diabase

153

16.3

0

0

1.7

1.3

  

Aphyric basalt

20

44.4

      

Olivine basalt

7

15.6

      

Plagioclase-olivine basalt

11

24.4

      

Plagioclase-olivine augite basalt

1

2.2

      

Plagioclase basalt

6

13.3

      

Total basalt

45

4.8

      

Pillow basalt

19

       

Mafic mylonite/cataclasite

3

0.3

      

Oxidized sulfide chimney

2

0.2

      
  1. Note: C-P = average crystal-plastic deformation grade on a scale of 0 to 5. Brittle stands for brittle deformation grade on a scale of 0 to 4