1
The Solid Phase of Marine Sediments
20
to as the “clay mineral of low latitudes” (Griffin et
al. 1968).
Illite is the most frequent clay mineral to be
found in ocean sediments (Fig. 1.16). It demonstrates a distinctly higher concentration in sediments at mid-latitudes of the northern oceans
which are surrounded by great land masses. This
follows particularly from its terrigenous origin and
becomes evident when the Northern Pacific is
compared with the Southern Pacific. The illite concentration impressively reflects the percentage
and distribution of particles which were introduced into marine sediments by fluvial transport.
The predominance of illites in the sediments of the
Pacific and Atlantic Oceans at moderate latitudes,
below the trajectories of the jet-stream, indicates
the great importance of the wind system in the
transport of fine-dispersed particulate matter.
The distribution pattern of smectite differs
greatly in the three oceans (Fig. 1.17), and along
with some other factors may be explained as an effect induced by dilution. Smectite is generally
considered as an indicator of a “volcanic regime”
(Griffin et al. 1968). Thus, high smectite concentraKaolinite
Illite
Smectite Chlorite
North Atlantic
20
56
16
10
Gulf of Mexico
12
25
45
18
Caribbian Sea
24
36
27
11
S o u t h A t l a n i c
1 7
4 7
2 6
1 1
North Pacific
8
40
35
18
South Pacific
8
26
53
13
Indian Ocean
16
30
47
10
Bay of Bengal
12
29
45
14
Arabian Sea
9
46
28
18
Table 1.6 Average relative concentrations [wt.%] of the principal clay mineral groups in the < 2 m carbonate-free
fraction in sediments from the major ocean basins (data from Windom 1976).
Fig. 1.15 Relative distribution of kaolinite in the world ocean, concentration in the carbonate-free < 2 µm size fraction (from Windom 1976).
The Solid Phase of Marine Sediments
20
to as the “clay mineral of low latitudes” (Griffin et
al. 1968).
Illite is the most frequent clay mineral to be
found in ocean sediments (Fig. 1.16). It demonstrates a distinctly higher concentration in sediments at mid-latitudes of the northern oceans
which are surrounded by great land masses. This
follows particularly from its terrigenous origin and
becomes evident when the Northern Pacific is
compared with the Southern Pacific. The illite concentration impressively reflects the percentage
and distribution of particles which were introduced into marine sediments by fluvial transport.
The predominance of illites in the sediments of the
Pacific and Atlantic Oceans at moderate latitudes,
below the trajectories of the jet-stream, indicates
the great importance of the wind system in the
transport of fine-dispersed particulate matter.
The distribution pattern of smectite differs
greatly in the three oceans (Fig. 1.17), and along
with some other factors may be explained as an effect induced by dilution. Smectite is generally
considered as an indicator of a “volcanic regime”
(Griffin et al. 1968). Thus, high smectite concentraKaolinite
Illite
Smectite Chlorite
North Atlantic
20
56
16
10
Gulf of Mexico
12
25
45
18
Caribbian Sea
24
36
27
11
S o u t h A t l a n i c
1 7
4 7
2 6
1 1
North Pacific
8
40
35
18
South Pacific
8
26
53
13
Indian Ocean
16
30
47
10
Bay of Bengal
12
29
45
14
Arabian Sea
9
46
28
18
Table 1.6 Average relative concentrations [wt.%] of the principal clay mineral groups in the < 2 m carbonate-free
fraction in sediments from the major ocean basins (data from Windom 1976).
Fig. 1.15 Relative distribution of kaolinite in the world ocean, concentration in the carbonate-free < 2 µm size fraction (from Windom 1976).