PLEISTOCENE DEPOSITS
97
A.O.D. Lithology
9'
Coarse sandy gravel.
London Clay.
The distribution of the Mollusca was noted in 1847 by Cotton
when he wrote : ''they are chiefly seen in the layers of sand
upon which the brickearth reposes . . . they appear to be partial
in their distribution, and are not met with in the former cut-
ting" (i.e. north of the High Road). He also noted that, as at
this site, bones were most commonly found at the junction of
the Corbicula sand with the overlying brickearth.
Shells were collected from two horizons in the High Road
pit by Dr. Corner (ca. 1893—vide Hinton, 1900, p. 273), and
recorded by Kennard and Woodward (1900, pp. 283-4).
Hinton also noted the lower shell bed in 1898 and wrote that
"towards the south it thinned out altogether" (1900, p. 274).
With regard to this latter statement, it is noteworthy that in
the Gordon Road trench the Corbicula sand is seen to thin
out northwards, and completely disappears only 5 feet north
of Section II, with a consequent loss of fauna both Molluscan
and Vertebrate. Kerney has pointed out (in lit. 1957 and vide
Appendix) that Corner's faunal collection recorded by Kennard
and Woodward agrees fairly well with that from the present
site.
The higher level of the base of the brickearth in the north
of the Connaught Road section (33' A.O.D.) compared with
that in the south (25' A.O.D.) is of some interest in indicating
the general position of the Thames at that time.
From the nature of their deposition, as bank-like masses,
no exact correlation of heights can be expected between the
various brickearths, sands and gravels. It is significant, how-
ever, that the sandy series usually overlies a basal gravel, or
"ballast", and is succeeded in turn by brickearths. The
uppermost layers of this normal fluviatile sequence are
frequently seen to have been disturbed and contorted by sub-
sequent solifluction, and in places to have been overridden by
"trail" gravels.