130
THE ESSEX FIELD CLUB.
inasmuch as, owing to the holidays, comparatively few members were able to
attend on that occasion, and the recent destructive landslips at Walton having
attracted much attention, it was deemed well to afford another opportunity of
visiting the spot, taking advantage of the invitation of the Geologists' Association
to join in an excursion. The members of the two Societies assembled at Walton
at about 12.30, under the guidance of Mr. W. Whitaker, F.R.S. Other geologists
present were Mr. T. V. Holmes, F.G.S. (President, Geologists' Association); Mr.
B. B. Woodward, F.G.S. ; Mr. E. T. Newton, F.G.S. ; Mr. C. D. Sherborn, F.G.S. ;
Mr. Herries, F.G.S., &c., and the Vicar of Walton, the Rev. J. T. Cooke, met the
party.
The visitors strolled through Walton, stopping on the way at the Tidal Mill.
Mr. Whitaker said that this kind of mill was extremely rare in the South of
England. Whether it was in active use he could not say, but as originally con-
structed, the water was imprisoned in a reservoir at high tide, and supplied motive
power for the mill as it ran out at low tide. The use of the immense power of
the tides would, he thought, soon become more general, and it was highly probable
that these mills would come into use again for the purpose of working electrical
machinery and lighting towns which were favourably situated.
After listening to this short lecture, the outlines of Harwich and Dovercourt,
looking very far distant across the fiat marshes, were pointed out, and the pro-
minent chimney at the cement works naturally led to some talk upon the familiar
subject of cement-stones.
The road then taken was through the town—past old-fashioned cottages, with
equally old-fashioned flowers blooming in the front gardens—along the breast-
work or sea wall, and on to the base of the cliff, inadequately protected from the
ravages of the sea by groynes of wood and concrete, to the cliff on the north.
This cliff consists at first of London Clay, which extends out along the foreshore,
and is capped above by Red Crag. The London Clay is jointed, almost
unfossiliferous (except for plant-remains in iron-pyrites), with cement-stones
(Septaria) and many small nodules of pyrites.
On arriving at the cliff containing the Red Crag the party descended to the
level of that formation (for the purpose of collecting its well-known shells) a little
eastward of Walton Tower. The lower part of the cliff was seen to consist of
London Clay, which, owing to the overlying beds being cut back by the action
of springs at their base, afforded a means of examining the Red Crag which the
existence of a perpendicular cliff would have prevented. Above the London
Clay was seen the reddish sand, containing shells, known as the Red Crag. The
shells were mostly reduced to fragments, a result only to be expected, as the
Crag at Walton is much current-bedded. The Crag fossils are of two kinds,
those derived from older formations, such as the London Clay and Coralline
Crag, and those more properly its own. From the London Clay are sharks-
teeth and the vertebra; of fish, while from the Coralline Crag have been derived
many Polyzoa. A complete list of the fossils found in it appears in the Geo-
logical Survey Memoir on sheet 48 S.E., by Mr. W. Whitaker, which should be
consulted by those interested in the matter. As the memoir consists of but
32 pages, and costs but ninepence, it should be in the pocket of every geological
visitor to Eastern Essex. The Crag rests on an uneven surface of London Clay,
and Mr. Whitaker remarks that the latter sometimes rises through the lower beds
of Crag. Mr. H. Stopes, F.G.S, (in 1874) noticed a thin bed of phosphatic
nodules in certain places at the base. Above the Red Crag is "a bedded loamy
deposit" which may be allied to the "Chillesford Beds" of Suffolk, and which is