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Geology
 Stop again at the
landing near the lifeguard station where the remaining steps lead to the
rocks and sand below. This is
an opportunity for a much closer view of what you saw from above.
As you look north beyond the final flight of stairs, you see evidence
of what causes the reefs. The sedimentary layers of rock on the bluff face show that a
block of the bluff (and extending well out into the ocean) is tilted
downward to the north at angles varying form 10 to 20 degrees. Some of the sedimentary layers are much harder than others,
the softer layers between being more easily eroded. The tilt and the differences in hardness produce the reefs.
At the “point” about 40 paces from the bottom of the steps you
can see how one hard sedimentary layer continues northward a few paces and
becomes one of the reefs. If you follow the next higher hard sedimentary layer (the one
with the most fossil shells), you’ll see it becomes the next reef about 50
paces still further north, and so on. Looking
at the bluff still further to the north, it appears that the tilting has
stopped. The transition between
the tilting and the non-tilting regions are mostly lost in the heavy
vegetation along the bluff. Careful
inspection of the bluff face both north and south of the first “point”
beyond the steps will reveal numerous “fracture” points where the
tilting begins, changes and ends. Judging
form the composition (and height) of the flat rocks extending offshore from
the “point” farther north, they may actually be from the same
sedimentary layer as the first reef mentioned (only beyond where the tilting
took place).
If you turn and face the bluff you can see an example of a vertical
“fracture zone”, and you may be able to locate a layer of rock that is
6-8” lower on the north side of the crack, indicating that side has sunk.
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