234 GEOLOGY OF THE ISLE Oh WIGHT. 



picturesque. The cascade falls in a perpendi- 

 cular column from a ledge 70 feet high, down 

 the midst of a deep chasm formed in dark ferrugi- 

 nous clays and sands, and surmounted by broken 

 cliffs 400 feet high ; and towering above all is the 

 majestic escarpment of Saint Catherine's-hill, 

 rising to an altitude of between eight and nine 

 hundred feet. The sketch in PL XII. shows the 

 section exhibited in the face of the cliffs. The 

 bands of greenish-grey sand and sandstone which 

 alternate with ferruginous clays in this division of 

 the greensand system, appear very prominent, 

 owing to the wearing away of the soft and friable 

 intermediate beds. 



As the face of the sandstone, after long exposure 

 to the atmosphere, separates into square blocks, 

 the appearance of the projecting bands of stone, 

 which are from ten to fifteen feet thick, is very 

 singular, and is not unaptly compared by Sir H. 

 Englefield to courses of masonry built up at dif- 

 ferent heights to sustain the mouldering cliffs. 

 The thin layer of ironstone grit which, as we have 

 previously remarked, is very constantly found in 

 this division of the greensand, constituting as it 

 were a line of demarcation between the upper 

 arenaceous deposits and the lower more argilla- 

 ceous group, intercepts the water that percolates 



