150
NOTES—ORIGINAL AND SELECTED.
Cauliflower Brickfield, the property of Mr. R. Page, where the pit exposed
a section of 12 to 14 feet brick-earth above sand. Mr. Holmes remarked that
the old river deposits of the Thames and its tributaries, on which they were
standing, covered a broad belt of flat country lying between the alluvial
flats bordering the Thames (which constituted the most recent river deposits)
and the higher ground of London Clay north of Wanstead, Romford, and
Upminster. The level of this tract varied from more than 100 feet above the
sea, towards its northern limits, to 15 or 16 feet close to the marshes of the
Thames between Barking and Rainham. Between London and Gravesend,
as between Windsor and London, the Thames had not only been cutting its
valley deeper and deeper, but had also been occupied in taking a more
southerly course than it once followed. This was shown by the much greater
breadth of river deposits to the north than to the south of the present
stream. It should also be remembered that the fall of the river would make
a deposit 60 or 70 feet above Ordnance Datum west of London, for example,
the equivalent of a bed at a considerably lower level east of that city,
Around the Ilford brick-pits the surface level is from 40 to 50 feet. But
Thames Valley Gravel had been seen at a height of about 100 feet above
O.D., on the new railway between Upminster and Romford, overlying the
Chalky Boulder-Clay, the latest deposit of the Glacial period in that part of
England. The Ilford deposits must therefore be still more decidedly "Post-
Glacial" in the only sense in which the term can be used, that is in the sense
of being more recent than the Chalky Boulder-Clay.
These old river-deposits consist of sand and gravel occasionally capped,
as at Ilford, by a considerable thickness of loam or brick-earth. The gravel
and sand has, doubtless, been brought down in the channel of the stream,
while the brick-earth is inundation-mud, deposited above the sand and gravel
during floods. Mammals would be especially liable to be drowned during
floods, while at the same time their remains, when quietly buried in the com-
paratively impermeable mud, would have a much better chance of preserva-
tion than if brought down in the channel of the stream.
Mr. Holmes concluded his remarks by referring to the most important
and interesting of the mammalian remains which had been found at Ilford by
the late Sir Antonio Brady and others.-' In answer to a question as to the
origin of the curious steep-sided hollows, filled largely with other material,
often seen near the surface of the Brick-earth, Mr. Holmes replied that
they had probably originated in natural cracks, the result of drying and
shrinking, which in many cases had been begun when the Brick-earth was
being deposited. These had been enlarged by the action of the weather, and
ultimately filled up with material at various periods and from a variety of
sources.
Recrossing the railway, the party proceeded along the Romford road in
a north-easterly direction. Passing the new Seven Kings Railway Station,
they entered, by permission of the G. E. R. Company, the large ballast-pit
on the northern side of the Romford road, about midway between Seven
1 Quart. Journ. Geol. Soc. vol. xlviii (1892). p. 365, and vol. 1 (1894). p. 443. Essex Nat.
vol. iv. p. 143-149: and vol. vii, p. 1-14.
2 See Henry Walker, "A Day's Elephant Hunting in Essex," Trans. Essex Field Club.
I., 27, and Proc. E.F.C, I , xii, and "A Visit to Ilford," p. xxviii, Dr. H. Woodward. "Tho
Ancient Fauna ot Essex," Trans. E.F.C, vol. iii, 1; Sir A. Brady, Catalogue of the Pleistocene
Vertebrata from the neighbourhood of Ilford, Essex. London, 1874.