142
THE GEOLOGY OF THE DISTRICT AROUND
DAGENHAM BREACH, ESSEX.
By T. V. HOLMES, F.G.S., M.A.I.
[Read at Field Meeting on July 23rd, 1892.]
IF we stand on the marshes six or seven feet below high water mark,
near the lake which forms a pleasant memorial of the Dagenham
Breach, and gaze around, we cannot but notice the contrast between
the scenery of the Kentish side of the Thames and that of the Essex
shore. Southward, beyond the marshes of Erith and Plumstead, we
see the bold ridge of the escarpment of the Lower Tertiaries with the
Chalk at its base, the London Clay capped by gravel rising above it
at Shooter's Hill. Where the surface of this high ground is composed
of Blackheath Pebble Beds its height above the river averages about
150 feet; but at Shooter's Hill the greatest elevation is about 420
feet. If, on the other hand, we look northward, we see, in the first
place, the limits of the marsh on which we are standing indicated by
the houses on the road connecting Barking and Rainham, which are
on the southern edge of the low, broad plain of river-gravel which
lies between the marshes and the higher ground beyond Ilford and
Diagram Section from Romford (N.) to Belvedere (S.) Seven Miles.
(Showing the river-gravel and alluvium on the Essex side of the Thames,
and the Lower Tertiary escarpment and fault on the Kentish shore.)
N. North. S. South. U.R. Upminster Railway.
T. & S.R. Tilbury and Southend Railway,
S.E.R. South Eastern Railway.
D. Dagenham. D.B. Dagenham Breach.
R.T. River Thames.
o.d. Ordnance Datum. l.c. London Clay.
b.b. Blackheath Pebble Beds. w.b. Woolwich Beds.
t.s. Thanet Sand. c. Chalk.
a. Alluvium. r.g. River Gravel.
f. Fault.