

SKY. GEOLOGY. SECONDARY STRATA. 343 



dimensions, the cliffs rising to the height of five or 

 six hundred feet and continuing with little variation to 

 Holme, where some alterations in the form of the land 

 prevent their dimensions from being further traced in 

 a continuous manner. It is apparent, that at the point 

 above mentioned, the same trap mass both overlies and 

 cuts through the strata, the details being so obvious 

 as to leave no doubt respecting the continuity of the 

 two. But the rectilinear appearance of the strata is 

 not altered at the place of junction, although it will 

 hereafter be seen that in similar cases on this shore 

 there are striking marks of irregularity and displacement. 



In attempting to describe the continuation of this 

 coast I must premise, that it is often impossible to 

 determine whether the strata which lie at an inaccessible 

 height in the cliffs consist of limestone or of sandstone; 

 since the external aspect of both, where they have been 

 acted on by the weather, is precisely the same ; the 

 limestone acquiring a grey arenaceous surface, whatever 

 its interior colour and texture may be, and the same 

 spheroidal concretions and organic remains being found 

 in both. It is plain that any judgment formed from 

 the fragments on the beach must be imperfect, as there 

 is abundant proof that the two substances alternate. 

 I am nevertheless inclined to think that after passing 

 Holme the limestone predominates, in some cases perhaps 

 even to the exclusion of the sandstone. 



The concretions above mentioned vary from two to 

 four feet in diameter, and are in the form of oblate 

 spheroids. As far as can be discovered without analysis, 

 they only differ from the surrounding rock in hardness, 

 and in consequence of this they are frequently found 

 lying loose on the beach after the surrounding softer 

 materials have been washed away. In a few instances 

 they are united in pairs by a thick cylindrical stem, 

 so as to resemble an ancient military projectile known 



