WESTLETON BEDS TO THOSE OF NOKEOLK, EIC. 109 



old forms gradually disappeared, the more northern and arctic 

 forms alone surviving, until in the terminal " Arctic Freshwater 

 Beds " both flora and fauna are such as show a climate fitly in 

 accordance with the now near approach of the great ice-sheet. 



The sea was probably too shallow to admit of the floating of 

 large bergs with their massive boulders, yet we are not without 

 evidence of ice-transport and ice-action on a small scale. 



Large unworn and unbroken flints and smaller subangular ones 

 are not uncommon. Small blocks of foreign rocks are, as before 

 mentioned, occasionally met with, and Mr. H. B. Woodward records 

 the occurrence in Norfolk of a block of basalt, about 18 inches 

 square, in the Pebbly Sands near Aylsham *, all pointing to trans- 

 port by ice. 



The Forest Bed, with its trees and mammalian remains, may 

 thence be traced northward as far as Cromer, but it finally dis- 

 appears about one mile N.W. of that place, where the Upper 

 Freshwater Bed and the basement beds of the underlying Forest-Bed 

 series come into contact. Mr. C. Eeid states that it is only at this 

 point and at Trimlingham that his Lower Freshwater Bed at the 

 base of the Forest Series is exposed. I cannot, however, agree v^ith 

 him in his interpretation of the Trimlingham section. I take 

 the upper beds, nos. 2 to 4 of his section (p. 33), to be the base of 

 the Mundesley series, nos. 5, 6, and 7 the Forest Bed, and no. 8 the 

 Norwich Crag. 



Another point at issue is whether the Weybourn Crag of Mr. Eeid, 

 considered by him to form part of his Forest Series, should be thus 

 grouped, or whether it represents the Norwich Crag. 



At the south end of the Forest-basin no marine bed underlies the 

 Forest Series f until at a short distance beyond Kessingland the 

 Chillesford Sands (Norwich Crag) set in. In the centre of the Basin 

 at Happisburgh and Mundesley, nothing is known of the lower beds 

 under the Forest Bed of Mr. Eeid. As we proceed northward, 

 owing to the thinning out of this latter bed, the base of the Mun- 

 desley Series with its pebble-bed (m) and derived bones comes, as 

 before mentioned, into contact with the lower part of the Forest- 

 Bed series. 



But the sections are mostly obscure, and it is not until we reach 

 the West-Eunton Gap (fig. 8) that the upper part of the series 

 is seen clearly as at Mundesley, and the special character of the 

 Westleton Shingle is again well marked. It here consists approxi- 

 mately of: — 



Per cent. 



FHnt-pebbles 47 



White quartz-pebbles 20 



Subangular flints 15 



Chert and ragstone 10 



Lydian stone and quartzite, and light- 

 coloured sandstone-pebbles 8 



100 



* Mr. Eeid's Meraoir, p. 53. 



t Except a doubtful specimen of Buccinum imdatum at Pakefield. 



