LOWER CHALK—DEVONSHIRE. 
133 
The next section is that of Whitecliff, west of Seaton, but the 
base of the Chalk in this cliff is only accessible at two points, first, 
where a fall has left a means of access over a broad talus slope of 
debris, and, secondly, in the roof of a cave near the point of Beer 
Harbour. There are, however, many fallen blocks in which the 
structure of the limestone can be more readily examined. 
In the cliff it can be seen that the lower surface of the Cenomanian 
limestone is a well-marked plane, generally very even and level, 
but here and there are angular pockets and fissures in the under¬ 
lying rock, which are filled with material from above. Although 
this plane of separation is clear, it is not conspicuous, because both 
beds are so hard and calcified that one does not project beyond the 
other. 
The Cenomanian limestone breaks away in one bed, but examina¬ 
tion of the fallen blocks shows that there are really two if not three 
layers. It seems to be thickest toward the northern end of the 
cliff, for some blocks below this show a thickness of nearly 4 feet, 
while at the southern end it is only 2 feet thick. Where thickest 
pieces of Ceriocava ramulosa have been found near the base, show¬ 
ing that Bed 10 of Mr. Meyer’s numeration enters into its com¬ 
position ; the central part is a compact shelly limestone, yellowish- 
white, with small scattered glauconite grains, but with many quartz 
grains, both large and small; it is full of fossils and broken shells. 
The upper part (Bed 12 or B) is greenish from the number and 
larger size of the glauconite grains; it also shows greenish and 
brownish stains, and contains lumps of partially phosphatised 
stone, but not so many fossils as the lower part. The microscopic 
structure of these beds is described in Chapter XXII. 
The upper surface of the limestone is a marked plane, and there 
is nothing to represent C, except nests of glauconitic sand embedded 
in the base of the overlying Turonian limestone. 
The sandy limestone and the overlying hard nodular chalk 
sink south-westward together below Beer Harbour, and form a 
ledge which is dry for some distance at low water. They emerge 
from beneath the pebble beach in the cliffs south of Beer, 
and the limestone is well exposed for a short distance in a low 
anticline, which succeeds the synclinal flexure of the harbour. 
Thence it keeps nearly horizontal for a little distance, but gradually 
dips southward to the caves (or Hall rocks) north of Pounds Pool. 
The section south of Beer is similar to that at Whitecliff, where 
first seen the Cenomanian limestone is 2J feet thick, but thins 
southward rapidly, and on the south side of the anticline, where 
the cliffs form a projecting point, it is only one foot thick. In the 
little cove on the south side of this point its thickness is 16 inches, 
and this increases rather rapidly to 2 feet, and finally to 2J feet. 
Attention may here be called to the fact that it is the lower part 
which varies so much in thickness, the upper course both here and 
at Whitecliff keeping about a foot, never less than 10 nor more 
than 18 inches. 
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4219. 
