Geology Reference
In-Depth Information
320
320
300
280
300
0
100
Time (kyr)
200
280
No erosion
Rate of fall 2500
μ
m yr
−
1
Production 1000
μ
m yr
−
1
260
320
300
280
m yr
−
1
Rate of fall 2500
μ
m yr
−
1
Production 1000
Marine erosion 800
μ
260
m yr
−
1
μ
320
300
Fig. 5.
Marine erosion and FST
development. The FST disappears at
erosion rate of 1750
m yr
1
. Unlike
subaerial erosion, marine erosion
modifi es depositional relief by remov-
ing sediment in the uppermost water
column and redepositing it at greater
depth (beyond the section shown). In
bottom panel, erosion rate is so high
that the carbonate factory cannot build
to sea level - lowstand systems tract
has fl at top at 5 m depth. Time lines and
numbering on axes as in Fig. 3.
280
Marine erosion 1750
μ
m yr
−
1
Rate of fall 2500
μ
m yr
−
1
Production 1000
μ
m yr
−
1
260
0
100
200
Distance in modelling space (m)
of sea-level fall, erosion and carbonate
production. Figure 8 illustrates various aspects
of this space. Figure 8a shows a plane in param-
eter space containing the axes for sea-level
fall and erosion. The FST anatomy is favoured
by low rates of both erosion and sea-level fall.
If both rates increase, standard-model anatomy
is created at rather moderate rates. If one rate
remains very low, very high rates of the other
process are required to reach standard-model
conditions. The boundaries between the two
domains resemble a hyperbola of the type
x
y
= constant, with the FST domain occu-
pying the area near the origin. A third axis -
carbonate production - extends perpendicular
to the sea-level-erosion plane. In Fig. 8a, the
