ALUM SHALE. 14r 



end beds, make their appearance ; bringing ns to the main bed of 

 alum shale : but the rocks have been thrown into the greatest disorder, 

 dipping in all directions, and presenting numerous bends and disloca- 

 tions. Thus it appears, that the subsidence has not taken place all 

 at once, in a single fracture, but in successive breaks. 



As the main bed of the aluminous schistus exists, to a certain 

 extent, at this point, an alum vi'ork was formerly carried on at the 

 shore, immediately to the south of the great slip ; but the present 

 Peak alum works are on the north side of the slip, and consequently 

 are at a great height above the shore. Their position is faintly seen in 

 the View, near the highest part of the back ground on the right. It 

 may be proper to add, that the sketch was taken when the tide had 

 begun to cover some of the lowest parts of the scar. 



That this great slip has been nearly coeval with the strata them- 

 selves, is obvious, not only from the bends or contortions in some of 

 the beds, which must have taken place when they were in a semi- 

 indurated state; but also from there being no vestige of it on the 

 surface, the alluvial covering filling up the chasms and inequalities 

 above, and thus affording proof of its having been deposited after this 

 catastrophe. There is nothing in the shape of the hill above, that 

 gives any indication of such a break ; for, though the strata on the 

 south have subsided 300 feet, the upper part of those on the north of 

 the slip have been so washed away, previous to the deposition of the 

 alluvium, that the hill, instead of falling to the south and rising to 

 the north of the great fracture, presents an appearance just the re- 

 verse. This precludes the possibility of tracing the slip to the 

 westward, or ascertaining the extent of its course into the interior. 



From the promontory of Peak to the north side of Robin Hood's 

 Bay, the upper strata are not found along the shore ; having been 

 washed away or removed, probably at the time of the great subsidence. 

 We find the main bed of alum rock, with its covering, at the alum 



