GEOLOGY. 275 



Ieeleth Slate. — The Coniston grit forms the base of the 

 third great system of Slate rock, called Ircleth, now Bannisdale 

 or Bretherdale Slate, reaching from Ravenstonedale to Duddon 

 Sands, and from Morecambe Bay to Windermere Village and 

 Hawkshead. It consists of masses of dark slate intersected and 

 broken by bands of quartz and beds of grit and limestone. Unlike 

 the other two great slate divisions, it has formed no hills of any 

 magnitude, though it has been greatly disturbed and contorted, 

 and contains a considerable part of the lakes of Windermere, 

 Esthwaite, and Coniston. A few fossils are found in it, and it is 

 perforated frequently by dykes of igneous rock. 



Kiekby Moos, Flags. — Another formation of slate stone, 

 called Hay Fell, or Kirkby Moor Flags, occupies the line of coun- 

 try between Kendal and Kirkby Lonsdale, and consists of flagstone 

 varying in structure and colour, and mingled irregularly with grit 

 and other rocks. This group affords great numbers of fossils, and 

 is also extensively perforated by basaltic and porphyrytic dykes. 



Old Red Sandstone. — The most considerable patches of Old 

 Red Sandstone and Conglomerate occur near Shap and on the 

 Cumberland side of the lower reach of XJUswater, forming the 

 fells in the former locality, and the hills of Dunmallet and Mell 

 Fell in the latter. These formations owe their origin to attrition 

 by the sea of the earlier rocks ; the cohesion of the coarse frag- 

 ments constituting the stone called Conglomerate, and that of the 

 fine particles, the Sandstone. This, and their position, as related 

 to the slate rocks, prove that these deposits were formed at a 

 period subsequent, not only to the formation of the slate groups, 

 but also to the disruption by the great Plutonic influences, — a 

 striking demonstration of the antiquity of these vast systems. 

 Unlike the Old Red Sandstone of other parts of Britain, that of 

 the Lake District is said to exhibit no fossil remains. 



Carboniferous Series. — The great central formations we 

 have noticed are engirdled by an almost complete circle, repre- 

 senting the important series of rock called Carboniferous, which 

 includes the coal measures and the extensive limestone deposits of 

 the country. These have been arranged in several groups, one of 



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