Reports & Proceedings — British Association. 557 



certain facts even more strikingly indicative of a former rapproche- 

 ment between the two continents than any pointed out by Wegener. 



The recurrence in America, on opposite sides of the old Appalachia, 

 of the two facies of the European Cambrian and early Ordovician, 

 which are here separated by the Caledonian chain, is perhaps the 

 most striking, the lithological and faunal distinctions and the 

 sequences of transgression and recession, different on either side 

 of the chain, being reproduced with remarkable precision. Again, 

 the continental and marine facies of the Devonian are separated in 

 both countries by boundaries which become conterminous on the 

 Wegener reconstruction. 



The equivalent line in the Triassic lies further south both in 

 Europe and America, but, as it passes into the areas of generally 

 defective correspondence in Spain and Central America, is less 

 valuable as a criterion. It should, on the other hand, be noted that 

 in America there are in the middle of the Carl)oniferous and 

 Cretaceous formations marked unconformities which have not been 

 recorded in Europe. The investigation of these discrepancies, 

 perhaps more apparent than real, might well form a test case for 

 the theory. 



Discussion on The Geological History of the North Sea Basin, 

 (a) Opener, Professor P. F. Kendall, President of the Section. 



The North Sea is situated upon an area of very ancient and 

 persistent depression, dating probably from Permian times. Coal- 

 measure rocks dip into the Basin in Belgium and Holland, north of 

 the anticline of Brabant ; probably in Lincolnshire ; and certainly 

 in Durliam and Northumberland ; they re-emerge at Ibbenbliren. 



The Permian rocks of Yorkshire and Lincolnshire increase steadily 

 in thickness from west to east. The Triassic rocks show no significant 

 change. Members of the Jurassic and Cretaceous series attain their 

 maximum development in Britain in the area bordering the North 

 Sea, and the Lower Cretaceous beds exhibit a deep-water jjhase 

 absent elsewhere in Britain. The Chalk thickens north and east of 

 London, partly by preservation of higher zones, and partly by general 

 expansion. In Yorkshire zone for zone it reaches its maximum 

 development, but in a deposit of this type this may not indicate 

 contemporaneous movement. 



The renewal of the Armorican movement in the South of England, 

 Northern France, and Belgium appears to have begun after the 

 deposition of the London Clay and Woolwich Beds, and after some 

 interruptions to have resumed its activity at or about the beginning 

 of Pliocene (Diestian) time. This may be regarded as the first 

 appearance of a North Sea as we know it. 



Harmer has suggested a coast-line connecting the Lenham and 

 other outliers spanning the Straits of Dover, joining up with the 

 main Diestian outcrops of Belgium. This view is accepted by the 

 Belgian geologists and accords generally with my own judgment, 

 though not without some reservations. This may be the stage repre- 



