QUATERNARY. 



475 



many Mammalian remains. Associated with this Rootlet-bed is a Um'o-hed, with 

 [/. pictofiim, etc., which serves to link the strata with the Upper Freshwater Bed 

 of Runton near Cromer. Much black peat overlies the Rootlet-bed at Gorton and 

 also at Kessingland. The rootlets were first noticed at Gorton by Mr. S. R. 

 Pattison/ and they have subsequently attracted much attention ; they possibly 

 belong to Fir trees. The age of the Pebbly Sand is doubtful : it may represent 

 the Leda-inyalis bed of Runton, or it may possibly belong to the Glacial Series. 

 The precise correlation of the other divisions is a subject on which considerable 

 difference of opinion exists, especially in reference to the identification of tlie 

 Ghillesford Glay. It would probably be safer, as well as simpler, to use the term 

 Forest Bed Series alone for the divisions above noted. 



QUATERNARY. 



Fig. 82.— Roches Moutonnees [Millstone Grit], Gwern-cefn-y-garreg, 



NEAR YsTRAD-FELLTE, IN BRECKNOCKSHIRE. 



(J. W. E. David.) 



The accumulations of Post-Tertiary or Post-Pliocene age in 

 England and Wales have a wide range, possess varied characters, 

 and occupy irregular positions ; whereas the earlier strata present 

 comparatively uniform characters, and occur in more definite 

 positions. We have to consider many deposits due to diverse 

 agents, not only Marine and Estuarine and Freshwater ; but we 

 have accumulations formed on land at various levels, on mountain 

 and in vale, some due to Glacial action, others to Chemical erosion, 

 while some again are purely Organic, and a few have been drifted 

 by Wind. Broadly speaking, the deposits may be grouped together 

 as belonging to one epoch, still in progress; the difficulty is to 

 correlate in point of time the minor and local divisions, which, 

 although the product of many distinct agents, may yet have been 

 in course of formation at the same time. We have, in short, 

 to discuss all the records of one period of geological time ; 

 whereas in dealing with previous formations, we find for the most 



^ S. R. Pattison, Geologist, vi. 207 ; Prestwich, Q. J. xxvii. 463 ; J. Gunn, 

 Q. J. xxxii. 123; Harmer, Q. J. xxxiii. 134. 



