142 
WEYBOURN CRAG. 
I am unable to accept Prof, Prestwich’s division of the Crag 
at Weybourn into three distinct series'—Westleton Beds, Chilles- 
ford Clay, and Norwich Crag—for if the thick clay bed be 
followed a short distance, it will be found to pass into sand, and 
another seam will appear on a slightly different horizon, or the 
whole deposit will be split up into thin alternations of sand and 
clay. Wherever masses of shelly Crag were divided by lami¬ 
nated clays, collections were made from each and the results were 
compared, but all the shell beds seem clearly to belong to the 
same horizon. The ^‘grey clay with fragments of wood,” west of 
Sherringham, also identified with the Chillesford Clay by Prof. 
Prestwich, is on a different horizon ; it belongs to the Forest- 
bed series, and has yielded a considerable number of mammalian 
bones. 
At Weybourn the cliff comes to an end, and shingle beaches 
and salt marshes separate the higher grounds from the sea ; but 
where the top of the Chalk is visible. Glacial Deposits rest imme¬ 
diately upon it, except at Letheringsett, near Holt. From the 
position and lithological character of the strata at this spot there 
is little doubt that they represent the beach deposit of the 
Weybourn Crag sea. No fossils were found, but the absence of 
shells is a common character in shingle beaches. The largest 
pit, marked Kiln on the map, is half a mile north-west of 
Letheringsett; it shows :— 
Feet. 
Boulder Clay, very chalky 
Streaky brick-earth and marl 
Shingle, almost entirely flint 
Loamy sand and large worn flints 
5 
- Otol 
3 
1 
Soil. 
Contorted Drift • 
Chalk, probably 20 feet above the level of the stream. 
Another part of the same pit shows 3 or 4 feet of alternating 
laminated clay and lines of pebbles. A pit by Book Hill, no’w 
disused and much obscured, shows similar though more sandy 
beds resting on the Chalk, which at that point is nearly 50 feet 
above high-water mark. 
Mr. Woodward has recognised similar representatives of the 
Pliocene beds at Guist, in the Valley of the Wensum, about nine 
miles to the south-south-west of Letheringsett (Fig. 35, p. 143), 
This section helps to connect the strata with the Crag of the 
Norwich district; but whether the shingle belongs to the Wey¬ 
bourn Crag, or to an older division, there is nothing to show. 
We have now traced, as far as possible, the stratigraphical 
relations of the Weybourn Crag to the Chillesford Clay, and to 
the Norwich Crag ; but it still remains to see what assistance in 
the comparison of the different deposits can be obtained from the 
included mollusca. In the Bure Valley we find Weybourn Crag 
distinctly overlying the Norwich Crag, with sometimes a seam of 
clay, often identified with the Chillesford Clay, between. But in 
other cases the Tellina halthica Crag rests immediately on the 
