Huge boulders of chalk
are, in fact, included in the clay, and have evidently been brought to
the position they now occupy by the same agency as that which has
planted blocks of syenite from Norway side by side with them.
The chalk, then, is certainly older than the boulder clay. If you ask
how much, I will again take you no further than the same spot upon
your own coasts for evidence. I have spoken of the boulder clay and
drift as resting upon the chalk. That is not strictly true. Interposed
between the chalk and the drift is a comparatively insignificant
layer, containing vegetable matter. But that layer tells a wonderful
history. It is full of stumps of trees standing as they grew.
Fir-trees are there with their cones, and hazel-bushes with their
nuts; there stand the stools of oak and yew trees, beeches and
alders. Hence this stratum is appropriately called the "forest-bed."
It is obvious that the chalk must have been upheaved and converted
into dry land before the timber trees could grow upon it. As the bolls
of some of these trees are from two to three feet in diameter, it is
no less clear that the dry land thus formed remained in the same
condition for long ages.
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