SKY. GEOLOGY. SECONDARY STRATA. 323 



on this line and proceed in geological order upwards 

 through the strata, by descending a stage nearer to 

 the valley of Strath; the lowest beds in altitude being 

 here often the highest in geological position. 



Proceeding thus to the south-west along a new line, 

 taken still from Broadford but at a point more north- 

 westerly, the limestone, which is at first concealed from 

 view, becomes shortly very conspicuous ; protruding 

 through the soil and rising above the surface in grey 

 low rocks visible at a great distance from the clearness 

 of their colour and the total absence of all mosses or 

 lichens, to which they seem never to afford the slightest 

 hold. It forms in some places two distinct ridges, 

 one of them presenting near Broadford a high range 

 of continuous hilly ground ; while in other parts these 

 unite, or become confounded by the intricate mixture of 

 some new eminences, or by the subsidence of the ridges 

 themselves. Finally they decline north-westward into 

 the valley, where, from excess of soil and vegetation, 

 the protruding limestone gradually disappears. 



Traversing the most conspicuous part of this irregular 

 ridge, no marks of stratification appear, but, in its 

 place, an irregular unstratified mass succeeds, totally 

 dissimilar to the former, and presenting the other cha- 

 racters usually found in the primary limestones, namely, 

 a crystalline texture, colours in which white and pale 

 grey are predominant, and a total absence of organic 

 remains. The same characters are found occasionally 

 extending even to the foot of the syenitic mountains 

 to the northward, wherever the limestone, which is not 

 often accessible, can be found. 



In this irregular mixture of secondary stratified limestone 

 and of unstratified crystalline masses, consists the ob- 

 scurity that involves the whole of this calcareous district; 

 the indications by which the two are connected being 

 so rare and so obscure, that they afford no grounds 

 for any conclusion, should they even excite suspicions 



