The Westleton beds here exhibit the characters we have noticed further south, consisting essentially of flint-pebbles with numerous white quartz-pebbles and a small admixture of pebbles of some peculiar varieties of siliceous sandstone, chert, and slate rocks ; mixed with them is a considerable quantity of drift-wood, both in large pieces and in matted small branches. Further, the basement bed of this series again often contains at places clay-pebbles derived from the Chillesford Clay *.
At this part of the coast the Westleton beds become more argillaceous, containing several subordinate beds of laminated grey clays without fossils. These clays sometimes replace, in great part, the sands and shingle, whence Mr. Gunn has applied to this series on the Norfolk coast the term of " the laminated clays," which often well expresses their character†‡. In this area the Westleton beds rarely exceed 25 feet in thickness ; and where the Forest-bed rises higher, as at Paston Cliff (fig. 36), or where the underlying beds have been denuded before the deposition of the Boulder-clay, they are sometimes wanting.
Fig. 36. — Section in Paston Cliff.
7. Sands, gravels, and laminated loams (base of 7).
6. Boulder-clay (lower division).
5. Sandy shingle.
5'. Elephant-bed.
4. Forest-bed.
As we proceed further northwards these beds assume a fluvio-marine character. Just south of Mundesley a thin seam of clay with freshwater shells, consisting of
Anodonta cygnea, Pisidium amnicum,
Unio pictorum, Bythinia tentaculata,
Sphaerium corneum, Valvata piscinalis,
which I have already described‡, appears at their base ; whilst on the north of Mundesley marine shells are intercalated with seams
- I had not found any shells on this part of the coast ; but Mr. Gunn pointed
out to me this summer a spot about half a mile north of Bacton Gap, where we procured from the lower bed of the Westleton shingle the following shells : — Purpura lapillus, Littorina rudis and L. littorea, Mytilus edulis, and a species of Scalaria, all much decayed. Some years since, Mr. Green, of Bacton, stated that the Crag was found in Bacton cliff ; but his statement remained discredited. This was no doubt the bed to which he referred.
† I hesitate to adopt this term, as the character is again repeated in the beds above the Lower Boulder-clay in the same cliffs, as well as in the Chillesford beds below. Nor in any case is a mineral designation convenient, especially for such variable beds. (See also my paper on the Mundesley Section, in the 'Geologist' for 1861, p. 68.)
‡ The Geologist ' for 1861, p. 68.
VOL. XXVII. PART I. 2 K
