SKY. GEOLOGY. SECONDARY STRATA. 337 



rocks of Rasay, to which their line of bearing can be 

 prolonged. Their dip is also to the westward, but the 

 angle is higher than is usually found in other places, 

 since it occasionally reaches even to seventy degrees. 

 The substances that belong to this deposit are the same 

 as those of Broadford, and they need not therefore be 

 further noticed ; their identity being proved by their com- 

 position as well as by the presence of the same organic 

 remains. I must however remark that the strata which 

 lie at the greatest distance from the mountain are regular, 

 but that nearer to it the limestone puts on the same 

 appearance as the unstratified rock of Strath. The con- 

 clusions to be drawn from this correspondence, respecting 

 the probable influence of the trap, are too obvious to 

 require further notice. It is perhaps almost superfluous 

 to say that the whole mass is much traversed by trap veins. 

 As the space occupied by Loch Sligachan amounts 

 to nearly a mile in breadth, there is no opportunity 

 of tracing these beds upwards according to the order 

 of succession ; but the first regular rock to be seen on the 

 opposite shore is a white calcareous sandstone followed 

 by a black and highly indurated one ; both lying in the 

 same conformable order to the limestone, and, for the 

 present, indicating its termination. These sandstones will 

 be described in their proper place ; and as the occurrence 

 of trap rocks attended by great consequent irregularities, 

 insulate this limestone from that which follows, and of 

 which the irregularity is still more remarkable, it is here 

 necessary to stop and attempt to determine its affinities 

 before proceeding to difficulties still more complicated. 



For this purpose it will now be convenient to refer 

 to the account of Scalpa, (which has unavoidably been 

 made posterior to that of Sky,) and to that of Rasay 

 already given.* In examining the former it will be seen, 

 that it consists chiefly of red sandstone similar to that 



* 



* Plate XV. 

 VOL. I. Z 



