I speak sober truth. Let me explain it step by step.
You know the chalk-hills to the south; and the sands of Crooksbury
and the Hind Head beyond them. There is one world.
You know the clays and sands of Hook and Newnham, Dogmersfield and
Shapley Heath, and all the country to the north as far as Reading.
There is a second world.
You know the gravel-pit itself; and all the upper soils and gravels,
which are spread over the length and breadth of the country to the
north. There is a third world.
Let us take them one by one.
First, the chalk.
The chalk-hills rise much higher than the surrounding country; but
you must not therefore suppose that they were made after it, and
laid on the top of it. That guess would be true, if you went south-
east from here toward the Hind Head. The chalk lies on the top of
the sands of Crooksbury Hill, and the clays of Holt Forest; but it
dips underneath the sands of Shapley Heath, and the clays of
Dogmersfield, and reappears from underneath them again at Reading.
Thus you at Odiham stand on the edge of a chalk basin; of what was
once a sea, or estuary, with shores of chalk, which begins at the
foot of the High Clere Hills, and runs eastward, widening as it
goes, past London, into the Eastern Sea. Everywhere under this
great basin is the floor of chalk, covered with clays and sands,
which, for certain reasons, are called by geologists Tertiary
strata.
Pages:
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119