Sedimentological Control Parameters and Compaction ...
385
The input parameters were set as follows: initial porosity CPo = 0.9,pressure-based compaction constant b=2.5xlO- s Pa- I , sedimentation rate SR=l
mm/a. The stepwise calculation was performed at lO-year intervals with sedimentary layers marked every 1000 years. The duration of the sedimentation was
limited to 8000 years. Figure 8 shows the results of the simulation with the solid
basement and the sediment surface as reference horizon, respectively.
8.1
Effects on Sediment Thickness
A duration of 8000 years of sedimentation in combination with a sedimentation
rate of 1 mm/a without compaction effects would result in a sediment thickness
of exactly 8 m. As illustrated by Fig. 8, the thickness of the entire sediment sequence is reduced to about 4m at the end of the time interval. In this case, compaction reduces the whole mud layer to about half its uncompacted thickness.
Years bpfore presen
8000 7000 6000 5000 1000 3000 2000 1000
0
1 . 0
C 3.0
' "
e
' "
11\
."
.0
'" 2. 0
>
o
.0
."
E
CI' 1.0
a;
:J:
-
-------Ypars bpforp prpspnt
8000 7000 6000 5000 1000 3000 2000 1000
0
Fig.8 Coupled model of sedimentation, compaction, and
pore-water movement. Reference horizon: solid basement
(above), sediment surface (below); gray pore water; black
sediment particles
385
The input parameters were set as follows: initial porosity CPo = 0.9,pressure-based compaction constant b=2.5xlO- s Pa- I , sedimentation rate SR=l
mm/a. The stepwise calculation was performed at lO-year intervals with sedimentary layers marked every 1000 years. The duration of the sedimentation was
limited to 8000 years. Figure 8 shows the results of the simulation with the solid
basement and the sediment surface as reference horizon, respectively.
8.1
Effects on Sediment Thickness
A duration of 8000 years of sedimentation in combination with a sedimentation
rate of 1 mm/a without compaction effects would result in a sediment thickness
of exactly 8 m. As illustrated by Fig. 8, the thickness of the entire sediment sequence is reduced to about 4m at the end of the time interval. In this case, compaction reduces the whole mud layer to about half its uncompacted thickness.
Years bpfore presen
8000 7000 6000 5000 1000 3000 2000 1000
0
1 . 0
C 3.0
' "
e
' "
11\
."
.0
'" 2. 0
>
o
.0
."
E
CI' 1.0
a;
:J:
-
-------Ypars bpforp prpspnt
8000 7000 6000 5000 1000 3000 2000 1000
0
Fig.8 Coupled model of sedimentation, compaction, and
pore-water movement. Reference horizon: solid basement
(above), sediment surface (below); gray pore water; black
sediment particles