174 GEOLOGICAL HISTORY. 



rates characteristic of the period immediately following the 

 Palichthyan age. This old shore is now almost 1200 feet above 

 the modern sea. 



This diagram shows the supposed first appearance of the land which is 

 now Cumbria, C 1 ; the ridge of Casterton Fell, C 2 ; the valley of the 

 Lune, v, excavated in Silurian strata, and filled with old red conglome- 

 rates; and the old (levelled) shore, S; and the sea-level, L 1 . As 

 mentioned hi the next paragraph, the land was depressed again, so as to 

 be covered in great part by water, whose relative level may be repre- 

 sented by the line L 2 . Then were deposited Mountain Limestone, Mill- 

 stone Grit, and Coal-measures. 



MEGALICHTHYAN PERIOD. The mountains already indicated 

 not far to the west of Yorkshire, were depressed again, and 

 with them the shore, which had been formed on the Yorkshire 

 Silurians so as to receive a thick deposit of mountain lime- 

 stone, the fruit of waters charged with a salt of lime, and innu- 

 merable shells and corals to which this salt yielded the materials 

 for their stony fabrics. As yet the area on which we are intent 

 was Sea but in many beds of sandstone, shale and coal which 

 alternate with the mountain limestone, we see evidence of 

 currents drifting spoils from neighbouring lands ; probably from 

 the upraised Cumbrian Alps, and other high ground farther 

 west and farther north ; for then the Highlands of North Britain 

 might perhaps be continuous to the Fells of Norway. 



This drift of materials from land is the more manifest, the 

 farther we go to the north. Under Ingleborough the Scar lime- 

 stone contains almost none of them ; when we reach the base of 

 Cross Fell it is broken up into many beds by these interpola- 

 tions. This drift did not in that period reach so far south as 

 Ingleborough ; and Derbyshire, Flintshire, and the south of 

 England and Wales, are equally free from any traces of it. 



