NOTES ON ESSEX GEOLOGY.
271
1897.
C. Reid gave us a list of "Pleistocene Plants from Grays,"
got from material collected by Prestwich many years before.12
"The plants occur associated with, or below the remains of,
mammoth and Corbicula fluminalis. They point distinctly
to a temperate climate and mild winters." 15 kinds of plants
were determined ; amongst them ivy and poplar, which had
not been recorded before as British fossils.
H. B. Woodward's Memoir on "Soils and Subsoils," was
published in this year ; but it is better to notice the second
edition, of 1906.
1898.
Dr. A. Irving's paper on the geology of the Stort Valley13
refers mainly to Hertfordshire, but touches on Essex, and the
author thinks that "the Stort-Cam watershed about Elsenham
may . . date from the Glacial Period," and that "the head-
waters of the Cam (which are in our county) no doubt represent
some reversal of drainage since Tertiary times."
In the Memoranda chiefly on Drift Deposits of Sir J. Prest-
wich,14 we have a section at Victoria Docks, a section of Mr.
Meesons [brickearth] pit at Grays, and notes of pits at Chadwell
and Braintree (pp. 409, 410), varying in date from 1847 to 1855.
T. V. Holmes treated of deneholes15 enforcing the arguments
advanced in our own report on the subject, which really belongs
to the domain of archaeology rather than to that of geology.
1900.
The second part of F. W. Harmer's essay on the "Pliocene
Deposits of the East of England," is devoted to the Essex Crag,
to which he gives the name Waltonian.18 This is taken to
be the oldest division of the Red Crag and is confined to Essex.
These beds are distinguished "by the strongly marked southern
facies of their molluscan fauna." The author divides the
Waltonian into two zones, that of Mactra obtruncata above (at
Beaumont, Oakley, Dovercourt and Harwich), and that of
12 Quart. Journ. Geol. Soc., Vol. liii., pp. 463, 464.
13 Proc. Geol. Assoc., Vol. xv.. pt. 6, p. 224, etc.
14 Geol. Mag., dec. iv., Vol. v., p. 404
15 Ibid., p. 447.
16 Quart. Journ. Geol. Soc., Vol. lvi., pp. 705-744.