440 GLANCE AT THE GEOLOGY OF 



described, is full of drift, which extends all the 

 way to the upper new red sandstone of Furness 

 Abbey before described, so it is impossible to say 

 what deposits adjoin the limestone on the west. 



It is very difficult to lay down the southern 

 boundary of the limestone, but it is generally given 

 in the geological maps which have been published, 

 in a line running from a little north of Aldingham, 

 on the Leven, to near Stank. Its north-west 

 range by Newton and Dalton, to the Duddon at 

 Ireleth, is pretty well defined. 



The most interesting points in the deposit are 

 the mines of red oxide of iron which are contained 

 in it. These have been worked for ages, probably 

 as long as any in the island, and still continue 

 unexhausted. 



This ore is now used in most of the iron works 

 of England and Scotland, for the purpose of mixing 

 with the poorer ores of the coal measures. 



It appears to lie in fissures and erosions in the 

 limestone, which in general run from south- 

 east to north-west ; but these main lines of direc- 

 tion are sometimes united by cross fissures. 



