464 S. V. WOOD, JIJN., ON THE KEWEE 



is to say, along the line by whicli tlie Crag river entered its estuary — 

 this division is, as I shall presently explain, obscure. These pebbly 

 sands I brought to the notice of geologists in 1866 * under the title 

 of the " Bure -Valley beds," from the circumstance that they yield 

 molluscan remains in that valley. They were a few years after this 

 described by Professor Prestwich, in his memoir on the Eed Crag t, 

 and by him called " the Westleton shingle." In the south-east of 

 Sheet 66 also these pebbles are heaped up into banks for some miles 

 on the east of Loddon ; but the banks are not oblique-bedded, and 

 are therefore, I infer, altogether of submarine accumulation. Here 

 at Loddon, as also in iig. IX. and generally over Sheet 66, these 

 pebbly sands are overlain by the Contorted Drift, hS ; but along the 

 coast-line stretching through Sheet 68 another formation, the Cromer 

 Till, h2, intervenes. Here, and thus overlain by h2, the sands 

 rest on the chalk or, where such are present, on the terrestrial 

 formations of the Crag already described. Where they rest on the 

 chalk, at Weybourne, they contain at their base Mollusca, of which 

 the bivalves have often their valves united, showing that they lived 

 there ; and at Woman Hythe, two miles west of Cromer, they 

 contain in their upper part, near where they pass into b2, My a 

 truncata, preserved with valves united, and in the position in 

 which the animal lived. They also yield Mollusca at Belaugh, 

 E-ackheath, and other places in the north-east of Sheet 66, which 

 here, as at Weybourne, also show a fluvio-marine character. They 

 have been divided into two beds by Mr. Clement Eeid, who alleges 

 that they are separated by a land and freshwater bed, extending, so 

 far as traces of clay with land and freshwater shells afford an in- 

 dication, along the base of the cliff. These traces are, in my opinion, 

 merely the result of the transport by the shore ice (formed in rivers 

 that discharged into this bay or estuary) of portions of the mud-flats 

 and banks of those rivers to which it froze during winter ;]:. The 

 only foundation that I can find for such a view as that of Mr. Eeid 

 is that the small boss of ijeaty clay with freshwater Mollusca which 

 shows itself for a few yards above the beach at Woman Hythe, and 

 which is overlain by these sands containing Mya truncata, has a few 

 feet of sand with Tellina balthica and other marine shells between it 

 and the chalk. This mass of peaty clay, however, is of so limited an 

 extent and thickness as to be quite within the power of such ice as 

 forms in the St. Lawrence, and there transports huge rock boulders 

 along the gulf of that river, to carry ; and as I observed a mass 

 of similar peaty clay (though without shells) of equal dimensions 

 imbedded in the Till itself on the east of Cromer, and strips or sheets 

 of chalk of yet larger dimensions are interstratified in the Till just 

 over this mass of peaty clay, such may have been the origin of the 

 bed in question, so far as its position in these sands is concerned. 

 As these sands extend eastwards through Sheet 68, they become, in 

 places, charged with carbonaceous debris, derived, in my view, from 

 the spoil of the swamps and river-banks represented by this peaty 



* Quart. Journ. Geol. Soc. vol. xxii. p. 546. t Ibid. vol. xxvii. p. 462. 



J See footnote*, p. 523, for similar evidences during Stages III. or V. 



