Miscellaneous Notes on Deneholes.
91
at the bottom of the valleys of the Lea and Ash, the Chalk
was more or less visible, while on ascending the hill-side in
Easneye Park we gradually found ourselves on the gravel
which caps the plateau on which the house stands, the
existence of any beds between the Chalk and Gravel being
masked by the sand and gravel that had rolled down the hill-
side from the top. On applying for information at the
Geological Survey Office, I found that no Drift Map of Sheet
No. 47 had been published, but I was kindly permitted by the
Survey authorities to take the details given in the map below
from a MS. copy for the information of the Essex Field Club.
Fig. 2.—Sketch-map to illustrate the geological position of the Easneye
Park Deneholes. (From the Geol. Survey Drift-Map, 47, by permission
of the Survey authorities). Scale 1 in. = 1 mile. a. Alluvium (Marsh).
b. Beds overlying Chalk (details omitted), c. Chalk, h. h. Position of
supposed Deneholes.
A comparison of the above Drift Map with the corresponding
portion of the published Geological Map of Sheet 47 (which
ignores the drift) shows that the Tertiary Beds underlie the
Gravel and Boulder Clay of the plateau, and that the escarp-
ment marking their line of outcrop keeps for many miles on
the eastern side of the valley of the Ash. In the Geol.
Survey Memoir treating of Sheet 47 it is stated that, on
the northern edge of the London Tertiary district, "both the