ALUM SHALE. 1-57 



been already stated, to the lowest shale ; and as they aie more norther- 

 ly than the foot of Huntcliff, they are a lower part of the series. Their 

 separation from Huntcliff, however, has been occasioned, not by ;i 

 mere washing away of the strata, but by some terrible convulsion ; 

 for instead of dipping to the south, like the strata at Saltburn, they 

 dip rapidly to the west and north-west, presenting their broken edges 

 to the east and south-east, in a long succession of parallel lines. 

 Hence the rocks nearest to Saltburn are the lowest part of them, in 

 geological position; and therefore, the most eligible spot for ascer- 

 taining by boring, what strata are the next under the aluminous beds, 

 must be on the shore a little to the east of Redcar, opposite the first 

 of these shelving beds. These rocks are named the Salt Scars. 



To the west of Saltburn, the remainder of the third range of alum 

 hills retire from the shore, forming the heights called Birdley moor 

 and Bernaldby moor. These hills, of which the latter is higher than 

 Boulby cliff, resemble the hills on the shore now described, having 

 gentle slopes towards the south or south-east, and steep cliffs towards 

 the north or north-west. These cliffs would be as precipitous as Rock- 

 cliff and Huntcliff, had the sea access to wash away the debris that 

 crumbles down from their fronts; but that debris having accumulated 

 at the foot of the cliffs, the hills are skirted even on the north with 

 grassy slopes, more or less considerable. The aluminous strata, and 

 the beds above them, crop out in the cliffs at various heights ; but 

 are generally so concealed by the debris and the alluvium, that their 

 state cannot be examined with the same accuracy as in the sea cliffs. 

 It is easy to see, however, in taking a general view of the strata of 

 these hills, that they have been separated by some violent convulsion 

 from the hills on the east, and that a vast break or subsidence must 

 have taken place between them and the next range of hills on the 

 south ; for if the beds at Eston Nab, the highest part of Bernaldby 

 moor, were continued southward in the plane of their dip, to the 



•2 R 



