616 BEPOET 1881. 



On the N. boundary of the area, 25 feet from the east end of these sections,. 

 200 from the west, the beds are again much contorted. One section showed 

 a mass of boulders and pebbles near the centre, looking as if tilted off an iceberg. 

 Another, about 10 yards to the west, showed a sand mass, steep and angular, 

 as if it had been deposited in one frozen lump. At another section, 200 yards 

 east, behind the passenger station, contorted beds were again well shown, with 

 layers of boulders, gravels, &c. Sands among them were very false-bedded. 



The stones found, though including many from the Lake District, chiefly come 

 from the Carboniferous beds of the West Riding. Limestones are usually 

 scratched and often beautifully polished. At all the places mentioned occasional 

 specimens occur from Lias and Oolite beds, so that an easterly drift must have 

 sometimes counteracted the prevailing set from the west. 



The main glacial beds approach nearest to the Purple Boulder Clay of 

 Messrs. Searles v. AVood and Plarmer. Floating ice, however, rather thau the 

 moraine profonde of an ice-sheet, seems best to account for the mixture of tough 

 boulder-clays with beds of boulders, gravels, and current-bedded sands. At most 

 sections there are indications that the upper glacial beds belong to a second glacia- 

 tion, less severe than the principal cold period. 



The post-glacial deposits are worked to depths of .30 feet and more ; in the 

 river-bed they may exceed 50 feet. The river is now 60 or 70 feet above its pre- 

 glacial bed, and probably 40 or 50 above the level to which it first cut down in 

 the opening of the post-glacial epoch. 



3. On tJie BrklUngtcn and Dimlingfon Glacial SJiell-beds. 

 By G. W. Lamplugh. 



In a section recently exposed in the cliff north of Bridlington, the ' basement '' 

 boulder clay was seen to enclose masses of smooth tough clay, light blue or dark 

 bluish-black in colour, mixed in places with a coarse yellowish-green sand. None 

 of these masses were large, and most were squeezed out so as to form streaks or 

 lenticular patches. Nearly all contained shells, some of which were unbroken, 

 but more were crushed, and the fragments dragged apart as if by shearing. Fora- 

 minifera were also present. The well-known bed, a few hundred yards to the south, 

 from which the Arctic shells were obtained, seems, from the description given, to 

 have been a similar, though larger, mass. Of the twenty-eight species of mollusca 

 collected from these patches, four are not included in the published lists of the 

 Bridlington shells ; viz. Hissoa Wyville-Thomsmii, Menestho alhula^ Leda tenuis, 

 and Leda lentinda. 



The surrounding boulder clay also contains many shells, chiefly fragmentary, 

 derived apparently from the same source, as under many of the unbroken valves 

 there still remains a little coarse sand, and of the twenty-five species identified, 

 only one species and one variety are not included in the published list, viz : 

 Pecten opereidaris and Mya fmncata, var. TJddevalJensis. 



At Dimlington, near Spurn, the same shelly boulder clay is again seen, and 

 contains similar patches of mingled sand and clay, with broken and unbroken 

 shells, Of the twenty-six species obtained from this locality, all except two are 

 included in the Bridlington list. The exceptions are Thracia pid)esce)is and 

 Cardium Gresnlandieum. 



In Filey Bay, on the beach opposite the village of Keighton, another of the 

 same shelly blue boulder clay was seen, containing similar clay streaks with 

 crushed shells. 



This bed forms part only of the 'basement clay' of Messrs. Wood and Rome, 

 as those gentlemen have included in their division a massive grey chalky boulder 

 clay, with very few shell-fragments, which irregularly overlies the shelly clay at 

 Dimlington, but is not seen at Bridlington. 



As the shelly clay extends to low water both at Bridlington and Dimlington, 

 its thickness and the character of the underlying beds are unknown. 



It appears to be the remains of an arctic sea-bottom, which was first covered 

 ■with fine glacial mud and then ploughed up and destroyed by ice. 



