ROCKS OF THE XOETHEEX HIGHLANDS. 



36^ 



the Hebridean are wanting, the Torridon occupying the entire 

 breadth of country between the Brown Flags and the Caledonian. 

 The fault, which is in the flags, is perfectly clear. The rocks are 

 broken into a chaos of fragments — pieces of shale, dolomite, flags, and 

 quartzite being thrown together in inextricable confusion. On the 

 east side the Torridon rises in a small overhanging cliff. 



The relations between the sections described are seen in the follow- 

 ing table. The numbers 1-6 stand for the sections. Up to the 

 flags the order is the same in all ; but between the flags and the 

 Caledonian the six sections present sice different successions. Which 

 of these is to be selected as the " clear ascending series " ? The 

 sections are too close together to permit of thinning- out, even if 

 there were no signs of dislocation. If we reject dislocation, we 

 have to invent new formations at random, substituting imagination 

 for the known principles of science. 



Table showing the Variations in the Ullapool sections. 



(1. (Obscure.) 



Torridon, 

 Quartzite, 

 Brown flags. 



| 2. S.Q 

 J 3. S. Q. 

 ] 4. S. Q. 



5. S.Q. 



Tor 



S.Q. = SaltereUa-qu&rtzite. 



3.) 



Dol. 

 Dol. 



Tor. 

 Tor, 



Tor. 



Tor. 





Heb. 



Quartzite. 



Heb. 







Heb. 



Dol. 





Heb. 









Tor. = Torridon Sandstone. 

 Heb. = Hebridean. 



)■ Caledonian. 



Dol. = Dolomite. 



A very simple hypothesis will render intelligible the facts enume- 

 rated. The zone between the Quartzite and the Caledonian is sliced 

 by several subparallel faults, which increase in throw from west to 

 east — that is, towards the junction with the Caledonian. On the line 

 of the Ullapool river, Torridon is first brought up through the 

 Quartzite, and further east through the Brown Plags or the Dolomite, 

 while still nearer the Caledonian the Hebridean is faulted up. On 

 Loch Broom and in the hills above, the facts are similar, though the 

 graduation in the throws is not quite so distinct. We shall find 

 the same law in operation in Assynt with still more striking 

 results. 



These conclusions are mainly negative. They show that in the 

 Ullapool area there is no evidence of a continuous series. At the 

 same time they dimly suggest the clear proof of inversion to be de- 

 scribed in future sections. 



ASSYSTT. 



Before we can reach a conclusion on the main issue, it will be 

 necessary to settle several preliminaries. Of these the most im- 

 portant are the true nature of the " Upper Quartzite," the " Logan 

 Rock," and the " Upper Limestone." 



A. The " Upper Quartzite " non-existent. 



Sir B. I. Murchison inferred the existence of an upper band of 

 quartzite from sections at two localities, Croc-an-drein and the Bal- 



