CHAP. IX.] JURASSIC PEEIOD. 151 



eastward there was a broad gulf over the eastern arm of 

 the Trias sic lake, but there is no reason to suppose that 

 the land connecting Scotland and Scandinavia was sub- 

 merged at this time. 



The view of Liassic geography above given differs from 

 what has been previously suggested l in the restriction of 

 the north-eastern part of the sea, and in connecting the 

 Sutherland basin with the western gulf instead of with the 

 eastern. Professor Hull in his restoration of Jurassic 

 geography 2 has depicted an extension of the sea round the 

 east of Scotland and entering the Sutherland basin from the 

 east, but he informs me that this map is intended to repre- 

 sent the epoch of the Oxford Clay, and, as we have no actual 

 evidence for any such continuous extension either of the 

 Keuper or the Lias, we can only consider the probabilities 

 which are suggested by the characters of the beds above and 

 below the Lias. Now there is nothing in the British Trias 

 to show that it was ever connected with that of Germany, and 

 I have adopted the view that even the Keuper was formed in 

 a restricted basin bordered on the east by a continuous 

 barrier of high ground (see Plate VI.), which rose from 

 beneath the eastern lip of the Northumberland coalfield, 

 just as the Pennine Range does from its western lip. If 

 this were so, then it is not likely that the Liassic sea en- 

 croached farther on to the land in a north-easterly direction 

 than it did eastward beneath England. Again, if we con- 

 sider the strata which overlie the Lias, we find estuarine 

 conditions prevailing in Yorkshire (see p. 139), and proving 

 the vicinity of land to the east and north-east at that time ; 

 hence it- is not likely that the land lay very much farther 

 off during the formation of the underlying Lias. 



The deposition of so great a thickness of dark-coloured 

 clay and shale in Liassic times is another point that calls 



1 " Historical Geology," p. 359. 



2 " Physical History of the British Isles," pL x. 



