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boundary of the Red Sandstone about Aspatria and Brayton, in 

 consequence of the enormous denudation that has taken place 

 since the fault came into existence. A simple diagram will illus- 

 trate this better than many words could do. 



We have only to suppose the rocks of the district to be planed 

 down to the level of the line A B, or thereabouts, and the present 

 state of things naturally follows. On the southern or upthrow-side 

 of the fault, both the Red Sandstone and a considerable mass of 

 the Coal-Measures have been removed. On the northern the 

 destruction has been of the Red Sandstone and beds above it. 

 There can be no doubt of the existence of Coal Measures north of 

 the fault, at any given spot, provided that they also exist there 

 south of it. But as the Red Sandstone lies unconformably on the 

 Carboniferous beds of various ages, the coal-bearing value of the 

 latter, when reached, may vary immensely in a very short lateral 

 distance. The writer in the " Carlisle Journal " also remarks that 

 Mr. Brockbank of Moor Park, after surveying the neighbourhood 

 of Aikton Pasture some years ago, came to the conclusion that 

 "it would be unwise to expend any capital in the hopes'of meeting 

 with the Coal-Measures in this locality." The reason, however, of 

 this was that Mr. Brockbank discovered that certain dark shales, 

 etc., about Aikton, which had been supposed to be Carboniferous, 

 were really Liassic. Consequently, both the Red Sandstone and 

 the Lias lie above the Carboniferous rocks in that locality. The 

 true problem is not as to the existence of Carboniferous beds north 

 of the fault ; but whether they are — at a given spot — sufficiently 



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