CHILLESFORD CLAY. 
133 
microscopic splinters of flint were observed, and a few dark-green 
opaque rounded or nodular grains, probably glauconitic. 
From Chillesford the clay stretches northward in an almost 
continuous sheet as far as the Aide, but it is unnecessary 
here to follow the outcrop, which has already been minutely 
described by Prof. Prestwich* * * § and the Pev. 0. Fisher.t The 
section at Iken Brickfield is, however, of special interest, for the 
pit—which lies nearly a mile and three-quarters east-south-east of 
Iken Church—shows a distinct overlap of the Chillesford Clay, 
so that it rests directly on the Coralline Crag. The section 
published by Prof Prestwich in 1849 was :— 
Feet. 
Flint gravel - - - - - - -lto3 
Laminated grey clays and sands with indistinct impressions "1 
Yellow sands ------- 4 
Coralline Crag - - - - - - - -1-30 
In 1886 the actual junction of the beds was no longer visible, 
but there is certainly not room for more than about two feet of 
strata between the Clay and the Coralline Crag, which is still 
visible in the middle of the pit. The base of the clay contains 
large unworn and unbroken flints. Bones have also been found, 
though not lately—unfortunately none of them appear to have 
been preserved. 
Crossing the Aide the Clay reappears around Aldborough, and 
on Aldringham Common, but the pits are of little interest, and 
the deposit seems to a large extent to be cut out by later gravels. 
North of Southwold, however, the Clay comes on in considerable 
thickness and can be traced continuously at the foot of the cliff, 
wherever sections are visible. We will therefore now follow the 
coast-line northward, only referring to inland sections where they 
are necessary to fill up breaks in the continuity of the cliffs. Of 
the cliffs we have carefully measured sections, made during the 
course of the Survey, by Messrs. Whitaker (Easton to Covehithe)t 
and Blake (Kessingland and Pakefield).§ 
In the Easton Bavent cliffs the Chillesford Clay commences as 
a thin deposit only 5 or 6 feet thick, but rapidly increases in 
importance towards the north, till it reaches nearly 20 feet. It 
consists of laminated loam and clay, often very sandy, and only 
yielding fossils at the northern end. Here Prof. Prestwich found 
the following species — 
Buccinum undatum. 
Littorina littorea. 
Natica cirriformis. 
Purpura lapillus. 
Turritella communis. 
Astarte compressa. 
Cardium edule. 
Corbula. 
Oyprina islandi(;a. 
Leda myalis. 
Lucina borealis. 
Mactra ovalis. 
- subtruncata. 
Mytilus edulis. 
Nucula Oobboldiaa. 
Tellina lata. 
-obliqua. 
One leaf-impression. 
* Quart. Journ. Geol. Soc., vol. v., p. 345 (1849) ; and vol. xxvii., p. 338. 
t Ibid., vol. xxii., p. 19. (1866.') 
X Geology of Southwold and of the Suffolk coast from Dunwich to Covehithe; 
plate. (1887.) 
§ Horizontal Sections, Sheet 128. 
