﻿548 8. V. Wood,jun. — American and British Surface- Geology. 



was, I contend, with disturbances of an intense character taking 

 place under the sea at this period that the emergence of the South of 

 England commenced, and it was to tlie long train of changes which 

 thus beginning continued through the period of minor glaciation that 

 we have hitherto called post-Glacial, and which I have endeavoured 

 to trace in my paper on the Wealden Denudation in the Journal of 

 the Geological Society for 1871, that in my view the South of 

 England, including the Wealden Yalley, was brought to its present 

 form and condition. 



In reference to the elevation of the greater part of the East 

 Anglian counties into a belt of land early in the progress of the 

 foi'mation of the chalky clay, there exist certain phenomena connected 

 with the valleys of that district which have long been a subject of 

 perplexity to me, and in reference to which the following passage 

 occurs in the recent paper by myself and Mr. Harmer, " On the 

 later Tertiary Geology of East Anglia," already quoted, viz. : " It is 

 also a perplexing feature that some denudation has occurred at 

 the bottom of valleys by which the Upper Glacial (or clay un- 

 distinguishable from it) rests directly on beds older than the Middle 

 Glacial sand, as is shown in Section XV. [of that paper] in the 

 case of the Ket Valley, and of which instances are also to be found 

 in the Waveney, Blyth, and Gipping Valleys. This, if the clay so 

 occurring be the Upper Glacial, seems to have taken place either 

 during the accumulation of that deposit or that of the Middle 

 Glacial, but to have been very partial or local." 



The explanation of the difficulty has since occurred to me ; and it 

 is, as already mentioned in these pages, that after the Middle Glacial 

 had been deposited and received by dropping a covering of morainic 

 clay, the area of the Eastern counties intersected by these valleys 

 was converted into land which formed a belt dividing the land- 

 ice from the sea, as is the case at the present time in Central 

 and South Greenland ; and that through the valleys traversing this 

 belt, or some of them, the land-ice issued in narrow tongue-like 

 glaciers to the sea, as it does in those parts of Greenland at the 

 present time. In Greenland this belt is formed of lofty land, but in 

 East Anglia the belt must have been of land even lower than the 

 present. 



The section afforded by the cutting of the Cromer Branch Eailway 

 at Thorpe near Norwich, some years ago, though puzzling at the time, 



accompanied the acute upthrow of these rectilinear ridges, just as Mr. Prestwich 

 shows it has done the portion of one of them which is continued through the Port- 

 land district. 



The restoration map No. II. of the plate to the paper hy myself on the "Weald 

 above quoted shows what I regard as the distribution of land and water at that par- 

 ticular stage of this emergence, when the oldest part of the gravel lying within the 

 Thames Valley commenced to form and when the "West and South of England were 

 to a great extent still submerged. 



I ought to add also that Mr. 0. Fisher in 1868 (Geol. Mag. Vol. V. p. 99), suggested 

 that the lofty gravels over the Southern counties represented the Upper Glacial. At 

 that time I regarded them as somewhat later, and as having accumulated after the 

 glacial clay had been removed from that part of England by denudation, but I have 

 for several years past given up this view in favour of that of Mr. Fisher. 



