continental margin sank thousands of
metres during its sedimentation.
‘hinge line’ that separates inland uplift
from offshore sinking is near the coast.
Geomorphologist Lester King
There have been repeated
tectonic episodes: always in
the same sense—the lands go
up and the sea floor down…
This is consistent with Psalm
104: 8, describing the draining of the
Flood water: “The mountains rose, the
valleys sank down to the place that you
appointed for them”.
The continental margin—
a mysterious geomorphic feature
Although few scientists address this
issue, the continental shelf and slope
are very difficult to explain within the
uniformitarian (slow and gradual) para-
digm. Non-catastrophic processes would
favour a gradual descent of sediments to
the ocean depths. There really should
be no continental shelf or slope (see
dashed line on figure 6). King described
“Briefly the shelf is too wide, and
towards the outer edge too deep,
to have been controlled by normal
wind-generated waves of the
ocean surface” (emphasis mine).
(1) The Atlantic type margin: this is generally seismically
inactive—i.e. few earthquakes and volcanoes (figure 2).
( 2) The Pacific type margin—seismically active (figure 3).1
In addition to the shelf and slope, Atlantic margins include
the added feature of a continental rise. Pacific margins usually
possess a deep-sea trench instead of a continental rise.
The profile of the Antarctica continental shelf differs from others
because the weight of the ice sheet has not only pushed down
the land but also the continental shelf.
1. Kennett, J., Marine Geology, Prentice-Hall, Englewood Cliffs, NJ, pp. 23–30, 1982.
Figure 6. The principal features of an Atlantic-type margin compared with the margin
that should occur (dashed line) if formed by normal wind-driven currents in the ocean
today. Vertical exaggeration is about 1/50.
Figure 5. Seaward thickening wedge of sedimentary rocks.
Distance from Shore (miles)
200 300 400 500 600 700
Figure 4. The nearly flat continental shelf
and the drop-off of the continental slope
of the southeastern United States (NOAA).
The drop-off is especially steep in the
north where it descends down to the
THE TWO TYPES