XCviii PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 1904, 



Europe could be upraised some 600 feet, the submarine prolongations 

 of the sea-lochs would once more become glens and straths, and their 

 rock-basins would again be turned into freshwater lakes. 



There is no similar series of well-marked submerged valleys on 

 the floor of the North Sea from which to estimate the amount of sub- 

 mergence of that tract, at least half of which, at no very distant date, 

 formed a land-surface that connected Britain with the rest of the 

 Continent. The charts show this sea-floor to consist of two distinct 

 portions. The northern half forms a plain, which appears to slope 

 gradually towards the north. The southern half, however, rises 

 somewhat rapidly from the edge of that plain into an escarpment that 

 runs in a north-easterly direction for a distance of 500 miles, from oft 

 Flamborough Head to the Skagerrak. From the top of this escarp- 

 ment the surface undulates southward as a higher submarine plain, 

 traversed by the still feebly-traceable submerged valleys of the Elbe, 

 the Rhine, and the Thames, and covering an area of more than 

 50,000 square miles. 1 An uprise of not more than 300 feet would 

 turn this tract into a rolling plateau of dry land, like the Downs 

 and Wolds of Yorkshire, which are its emerged continuation. Such 

 an amount of uplift would probably be amply sufficient for the 

 transaction of all the later geological history of the region. The 

 conversion of the area into a sea-bottom mav not have been a 

 continuous process. It was probably in operation during the early 

 stages of the Glacial Period, and its latest phases come down at 

 least into Neolithic time. 



2. The sheets of peat with stools and trunks of trees, known as 

 Sunk or Submerged Forests, and of such frequent occurrence 

 around the coasts of the British Isles, have long been confidently 

 regarded as proofs of recent subsidence of the land. That they 

 generally mark former land-surfaces cannot be doubted, for the 

 tree-stumps are seen to send their roots down into the soil under- 

 neath, and manifestly stand in the places where they originally 

 grew. The presence of hazel-nuts, elytra of beetles, land-snails, 

 and other terrestrial organisms, affords further confirmation of this 

 conclusion. The great majority of these vegetable accumulations 

 are found between tide-marks in bays and estuaries, and in many 



1 See the excellent chart accompanying the paper by Mr. John Murray, 

 Proc. lust. C. E. vol. xs (1861) p. 314. The submerged land-valleys off 

 the coasts of South Wales, Devon, and Cornwall have been described by Mr. T 

 Codrington, Quart. Journ. Geol. Soc. vol. liv (1898) p. 251. 



