24 PALAEOZOIC TIME. [CHAP. II. 



may have been mainly due to a less rapid rate of deposi- 

 tion. " If Mr. Hicks' views of the physical geography of 

 the Cambrian period were correct, there ought to be in 

 the middle and upper portions of the Swedish series many 

 signs of littoral conditions. . . . The facts, however, rather 

 tend to show that most of the Swedish Cambrian rocks 

 were deposited in a deeper sea and farther from land than 

 the British." 



The fact is that in Scandinavia, as in Britain, there are 

 great variations in the thickness of the Lower Cambrian 

 rocks ; thus in Norway the lowermost sandstones are 2,000 

 feet thick, while in Sweden they are only 100 feet. Again, 

 the Olenus beds in Norway contain sandstones and quart- 

 zites, but in Sweden they are wholly shales with bands of 

 limestone. These facts point rather to the conclusion that 

 the greatest mass of land lay to the north-west, for coarse 

 sediments are likely to thicken in the direction of land and 

 not away from it, as Dr. Hicks seems to suppose. The 

 Russian succession is not antagonistic to this conclusion, 

 for the whole Cambrian series is not 700 feet thick ; the 

 basal sandstones are 300 feet, and the overlying beds are 

 such as would be formed at a distance from land, being 

 blue clays surmounted by glauconitic shales and limestones 

 like some of our Cretaceous beds. 



All the available evidence certainly seems to favour the 

 view taken by Professor Hull, 1 that the greater mass of dry 

 land lay to the north-west of Europe, and occupied a large 

 part of what is now the North Atlantic Ocean. There may 

 have been smaller but still extensive tracts of land of the 

 European area, as is plainly indicated in England and 

 Bohemia ; nay, it would appear that in Lower Cambrian 

 times there was in Europe more land than sea, and that 

 the subsequent changes throughout the Upper Cambrian 

 and Ordovician periods tended to reverse this state of things 

 1 " Physical History of the British Isles," p. 61. 



