DEPOSITS AND ELEVATION. 15 



But these plateaux furnish yet other indications of marine 

 beach- wear. The strata of the Head are more or less 

 horizontal. Some beds are extremely hard and compact, 

 and apparently suffer superficial degradation only in the 

 very slightest or, at any rate, most uniform measure. 

 Others weather rapidly, and disintegrate to a considerable 

 depth, so as to shatter easily under the hammer. There 

 are several places near the highest levels of the hill where 

 a hard layer has been stripped clean of all the superin- 

 cumbent stone except the beach-boulders just referred to. 

 The wear of these flats is various. Sometimes (as, for in- 

 stance, on the hill at the south of the lighthouse) the sur- 

 face is cut and furrowed, and worn in fissures, potholes, 

 and other forms, very similar to those of the like beds in 

 like position in the intertidal spaces below. Whether 

 it be that there has been no perceptible wear since the 

 waves covered this rock, and the lighter touch of wind 

 and rain has only corroded surfaces that the denser 

 and more constant fluid carved, or that we have in this 

 sculpture nothing more than the effect of the rain of ages, 

 it seems probable that in the bared stratum we see only an 

 ancient scar or tidal level. I submit that, so far from 

 proving ice-action, the blocks, and still more these flats 

 (if indeed tidal, or perhaps whether tidal or not), in truth 

 discredit that supposition. 



A similar, or even more marine-looking, horizontal scar 

 of apparently tide-worn rock forms the highest plateau 

 of the Little Orme^s Head, and carries the like proof 

 there. 



In my next section I shall adduce still other evidence 

 that these hill-tops have not been ice-clad since they were 

 last below the sea-level. 



Other indications of long-continued tidal action, if not 

 exactly in the shape of beaches, are abundantly to be seen 

 in the actual vertical outlines of the cliffs which bound the 



