92
F.T. Millero
Table 4.1. Typical anoxic basins (Millero 1996)
Name
Location
Bottom(m)
SiII(m)
Maximum H 2 S (11M)
Goteland Deep
Baltic Sea
249
60
20
Cariaco Trench
Caribbean Sea
1390
150
160
Lake Nitinat
British Columbia
250
4
250
Saanich Inlet
British Columbia
236
65
250
Black Sea
Europe
2243
40
350
Framvaren Fjord
Norway
350
2
6000
Concentration
Processes
Electron
Eh range (mV)
/ .... ~: ........................
acceptor
Aerobic respiration
°2
200 to 800
Denitrification
NO)
50 to 750
Mn reduction
Mn2+
150 to 600
Iron reduction
Fe3+
-500 to 50
SOaDepth
Sulfate reduction
SO~
-650to-200
Fig. 4.2. Schematic representation of chemical profiles in a stratified water column
The loss of oxygen in a basin or sediment pore waters causes a series of reactions
to occur in a given sequence that is shown in Fig. 4.2. In an aerobic environment, O2 is
the electron acceptor and plant material can be oxidized by
The oxidation of typical plant material (Redfield et al. 1963) gives