21 



clearly unconformable to the rocks beneath. In other words, the 

 St. Bees Sandstone and Gypseous Shales had evidently been planed 

 down by denudation before the Kirklinton Sandstone was deposited 

 above them. This denudation appears to have been greater towards 

 the N.E. end of the Basin than about the centre. Thus, while at 

 Great Orton one hundred and thirty-two feet or more of the 

 Gypseous Shales were left, at Netherby not only were the Gypseous 

 Shales swept away, but much of the St. Bees Sandstone also. This 

 unconformity may therefore be a sufficient reason for the non- 

 appearance of the Gypseous Shales at Cummersdale. But, in 

 addition, a fault known to exist between Brackenbank on the 

 Eden and Newbiggin on the Petteril, is probably prolonged 

 westward of the Caldew about Dalston Hall. This fault having a 

 downthrow to the north, the beds on its northern side, along its 

 course, are geologically higher than those on the southern. There- 

 fore a prolongation of this fault across the Caldew Valley at Dalston 

 Hall, and (below the Lias) towards Great Orton, would cut off 

 the Gypseous Shales along its line, and bring in the Kirklinton 

 Sandstone on its northern side. And as the Kirklinton Sandstone 

 rapidly thickens as we approach Carlisle from Cummersdale, 

 wells of considerable depth in or near the Border City give no 

 information about any beds below that rock. Consequently we 

 do not know how far the Gypseous Shales maintain their existence 

 towards Beaumont and Carlisle, beneath the Kirklinton Sandstone, 

 before they die away. 



It is evident, however, that they must die away long before the 

 northern end of the Basin is reached. This is shown not only by 

 the fact that in the Hether Burn, the Lyne, and the Esk the Kirk- 

 linton Sandstone rests directly on that of St. Bees, but by the 

 boring at Lynehow, formerly Justustovvn, on the river Lyne about 

 a mile below Westlinton. At Lynehow about one hundred and 

 seventy feet of Kirklinton Sandstone rested on an unknown thick- 

 ness of St. Bees. The two sandstones are easily distinguishable 

 from each other, not only in sections of any size, but, usually, even 

 in hand specimens. The lower beds of the Kirklinton Sandstone 

 are mainly bright red, and the rock generally is very false-bedded. 



