EPPING FOREST
A SKETCH OF THE GEOLOGY OF
EPPING FOREST1
By T. V. Holmes, Esq., F.G.S.
A glance at a geological map of South-eastern
England shows that London stands in the midst
of a district of Tertiary clays and sands. These
occupy the surface of a large tract of country,
which, widening eastward till it includes Ipswich
and Canterbury, becomes narrower westward and
dies away around Newbury and Marlborough.
Immediately outside this Tertiary area appears a
belt of country of very variable breadth covered
by the well-known soft limestone known as the
Chalk, which underlies the Tertiary district, and
comes out to the surface in Kent, Surrey, and
Hampshire southward, and northward in Suffolk,
North-western Essex, Hertfordshire, and other
counties. In Essex, south of the Tertiary area,
Chalk appears only in the small district between
Purfleet and East Tilbury ; north of it Chalk may
be seen north-west of a line drawn from Ware
through Bishop Stortford to Sudbury.
Thus in Epping Forest only Tertiary, and rocks
of still later date, appear, the oldest being that
known as the London Clay. The following section
gives the nature and thicknesses of the strata
found beneath the London Clay in a deep boring
at the Great Eastern Railway Station, Loughton
(Trans. Essex Field Club, vol. iv. pt. ii. p. 158):—
1 Those requiring fuller information may be referred to Mr.
W. Whitaker's Memoir on " The Geology of London, and of
part of the Thames Valley." (Stanford.) 2 vols.