pai't 1] ANNIVERSARY ADDRESS OE THE PRESIDENT. lxv 



gulf with an average breadth of 3 or 4 miles, having its outlet 

 between Filey and Speeton. South of Flamborough Head tbe whole 

 of Holderness would be under water, with creeks here and there 

 running into the mouths of some of the Chalk valleys. The 

 Humber would become a strait, hardly wider than at present, 

 where it cuts through the "Wolds, but giving passage to a flood 

 which would inundate the Vale of York up to Boroughbridge, 

 throw narrow tongues southwards up the valleys of the Ancbolm 

 and Trent, and spread out broadly between Selby and Doncaster. 1 

 In East Lincolnshire the conditions would be as in Holderness, 

 with the sea everywhere up to the foot of the Wolds, and at least 

 one deep channel leading into them. The Wash, broadened con- 

 siderably on the Lincolnshire side, would be the entrance to a great 

 bay covering the whole of the Fen country, with the exception of 

 a few islands between March and Cambridge. East of this bay, 

 nearly one-lmlf of Norfolk and almost as much of Suffolk 

 would be submerged, with an intricate system of sounds, creeks, 

 and water-passes breaking up the remnants of the land. 2 Farther 

 south, up to the termination of the glaciated area, the drift lies 

 mostly above sea-level ; but some of the valleys contain gravels 

 below sea-level which appear to date back to Glacial times, and 

 the same is the case also with the coastal valleys south of the drift- 

 covered area. If these old gravels were removed, along with their 

 covering of more recent alluvia, the indentations of the coast of 

 Essex and North Kent, and the estuary of the Thames, would be 

 considerably enlarged. Similarly, all round the south coast the 

 clearing away of the valley-deposits, along with the Coombe Rock 

 and Head, would admit the sea farther into most of the bays and 

 creeks ; without, however, seriously modifying the present outline 

 of the land. 3 



1 The underground contours of the drift in the south-western part of the 

 Humber basin are complicated, and require further investigation. 



2 The area of drift below sea-level in Norfolk & Suffolk is shown in two 

 maps in the Geological Survey memoir ' On the Thicknesses of Strata in the 

 Counties of England & Wales' 1916, pp. 99 & 127. I have copied these 

 maps with some slight modification ; but, when further information is obtained 

 from borings, it is likely that the maps will require alteration. Reference 

 should also be made to a paper ' On the Age of the Suffolk Valleys ; with 

 Notes on the Buried Channels of Drift ' by P. G. H. Boswell, Q. J. G. S. vol. 

 lxix (1913) pp. 581-618. 



3 The areas affected along the south coast are too small and irregular to 

 be shown on the map : particulars respecting many of the inlets are contained 

 in a paper ' On some Submerged Rock- Valleys in South Wales, Devon, & 

 Cornwall ' by T. Codrington, Q. J. G. S. vol. liv (1898) pp. 251-76. 



VOL. LXXVI. e 



