nd and dropped on
the shore of the ocean.
[Illustration: SEA CLIFFS SHOWING A SERIES OF STRATIFIED ROCKS.]
You may see these layers for yourself as you walk out into the
country. Look at the first piece of bluff rock you come near, and
observe the clear pencil-like markings of layer above layer--not often
indeed lying _flat_, one over another, and this must be explained
later, but however irregularly slanting, still plainly visible. You
can examine these lines of stratification on the nearest cliff, the
nearest quarry, the nearest bare headland, in your neighborhood.
But how can this be? If all these stratified rocks are built on the
floor of the ocean out of material taken _from_ the land, how can we
by any possibility find such rocks _upon_ the land? In the beds of
rivers we might indeed expect to see them, but surely nowhere else
save under ocean waters.
Yet find them we do. Through England, through the two great
world-continents, they abound on every side. Thousands of miles in
unbroken succession are composed of such rocks.
Stand with me near the seashore, and let us look around. Those white
chalk cliffs--they, at least, are not formed of sand or earth. True,
and the lines of stratification are in them very indistinct, if seen
at all; yet they too are built up of sediment of a different kind,
dropping upon ocean's floor. See, however, in the rough sides of
yonder bluff the markings spoken of, fine lines running alongside of
one another, sometimes flat, sometimes bent or slanting, but always
giving the impression of layer piled upon layer. Yet how can one for a
moment suppose that the ocean-waters ever rose so high?
Stay a moment. Look again at yonder white chalk cliff, and observe a
little way below the top a singular band of shingles, squeezed into
the cliff, as it were, with chalk below and earth above.
That is believed to be an old sea-beach. Once upon a time the waters
of the sea are supposed to have washed those shingles, as now they
wash the shore near which we stand, and all the white cliff must have
lain then beneath the ocean.
Geologists were for a long while sorely puzzled to account for these
old sea-beaches, found high up in the cliffs around our land in many
different places.
They had at first a theory that the sea must once, in far back ages,
have been a great deal higher than it is now. But this explanation
only brought about fresh difficulties. It is quite impossible that the
le
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