TABLE 9.2 Bulk Sedimentation Data

Site

Sedimentation Ratea

Mass Accumulation Rateb

Total Rain Rateb

% Preserved

Recycled Fluxb

Atlantic          

 

 

 

 

 

HAP

10

4,500

2000

225

-2,500

HAP

1

650

1190

55

540

Pacific          

 

 

 

 

 

MFZ

5.9

3,240

3,970

82

730

JDF

1.6

840

2,500

34

1,660

NS

19

9,690

19,010

51

9,320

MW

11

4,440

6,050

73

1,650

G

1.3

650

1,030

63

380

H

0.66

110

2,550

4

2,440

M

1.0

288

1,980

15

1,692

S

0.1

32

1,030

3

998

C

1.7

848

3,701

23

2,854

a Units of cm/1000 yr

b Units of mg/cm2/yr.

TABLE 9.3 Refractory Element Fluxes  

 

A1      

Fe    

Ti    

Site

Rain Rate

Burial Rate

% Preserved  

Rain Rate

Burial Rate

% Preserved  

Rain Rate

Burial Rate

% Preserved

Atlantic                      

HAP

47

312

664  

25

171

684  

2.28

18.51

812

NAP

52.4

59.8

114  

29.5

33.1

112  

3.01

3.43

114

Pacific                      

MFZ

220

254

115  

135

162

120  

12

15

125

JDF

30.6

29.1

95  

19.3

44.7

232  

NS

940

746

79  

—  

46

52

113

MW

200

308

154  

—  

11

30

273

G

20

34

170  

—  

H

7

6.4

91  

3.75

5.4

144  

0.74

0.4

54

M

15.1

14.2

94

15.7

20.3

129  

0.85

0.97

114

S

1.8

2.1

117  

1.01

1.3

129  

0.12

C

5.41

4.8

89  

2.61

3.2

123  

0.21

NOTE: All rates are in units of mg/cm2/yr.

represents an artificial flux. The trap intercepts the cycling of particles from the bottom into the water column and back to the bottom. This process increases the residence time of settling particles in the water column (Walsh et al., 1988b), but not the particulate flux to the bottom.

These difficulties cannot be overcome by mooring a single trap within the water column. Studies that involve deployment of 3-4 traps within the bottom 1000 m, however, indicate that local resuspension is not significant at elevations a few hundred meters above bottom (Dymond et al., 1981; Fischer, 1984; Walsh et al., 1988b). In this paper we will use particulate flux measurements from traps above the resuspension zone (Figure 9.2) to extrapolate the rain rate to bottom depths.

Temporal variations in the particle flux provide another complication to estimating the particulate rain to the bot-



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