92 Miscellaneous Notes on Deneholes.
Thanet Sand and the Reading Beds are here so thin and so
hidden by Drift that they could hardly be anywhere separated
on the one-inch map" (p. 12). The Thanet Sand is in
character the same as in W. Kent and S. Essex. The over-
lying Reading Beds are very thin, and consist of mottled clay,
sand, and loam ; they rarely reach a total thickness of 40 ft.
As the mansion at Easneye Park appears to stand close to
the outcrop of the Tertiaries,—below the Drift,—they must
be very thin in its immediate neighbourhood. Only a well or
boring close to the house could give accurate information as
to the nature and thickness of the strata there between the
Gravel and the Chalk. For not only are the constituents of
the Reading Beds very variable, but, as the overlying Drift
Beds lie uncomfortably above them, the former may have
suffered considerably from denudation before the deposition
of the latter. More or less clay, however, is usually found in
the Reading Beds, and probably at Easneye Park throws out
the water which sinks through the gravel above, as it is
stated to do about half a mile N.E. of St. Margaret's Railway
Station.
Of the Boulder Clay, Brick-earth, and Post Glacial Gravel
shown on the map, I need only remark that they overlie the
gravel capping the plateau. The outcrop of the London Clay
keeps a little eastward of that of the Lower Tertiary Beds, to
which it is conformable. It is hardly likely to be present—
below the Drift—so far westward as the house, though a
small patch of it is shown in a valley between the Reading
Beds and the Post Glacial Gravel, in the S.E. corner.
One circumstance—apart from the number of the depres-
sions (twenty-five)—is decisive against the supposition that
they may be due simply to natural causes. No hollows are
in the least likely to be forming in the chalk of the neigh-
bourhood, inasmuch as the springs at Amwell and New River
Head show that it is permanently full of water. The number
of the depressions also sets aside any notion that they may
be on the sites of old wells. Nor are they at all likely to be
on the sites of old excavations for flints in the gravel; from
the abundance of unworn flints in the chalk of the valleys