IIONEYMAN GEOLOGY OF AXTIGOX ISIIE COUNTY. 57 



Section 11th. — McAras Brook. 



This section begins -with amygdaloid (trap) ; the brook fh.ws 

 through it. Passing through this we come to red slates ; then 

 continue up the brook, mixed grey and red slates with trap ; these 

 slates are apparently non-fossiliferous. As they succeed the strata 

 of the shore section which are the equivalent of the lower Ludlow, I 

 regard them as higher, and although they occur on the north side of 

 the series I consider that they correspond with the red slates of the 

 syncline in section 8, and with the red slates of last section (10). 

 Still ascending the brook we have the lower carboniferous grits of 

 the overlying formation. 



Passing through the woods to the north to a distance of about 



. we reach an outcrop of red slates with trap, (in situ?) 



These seem to be a continuation of the red slate ^band) of 

 McAdam's Brook. 



This ends the section. 



Return to Arisaig. 



To the south of the section there is a valley through which a 

 branch of Knoydart Brook flows in a westerly direction. On the 

 south side of the valley rise the Arisaig mountains. 



We descend into the valley and find a pathway along the side of 

 the brook. This valley is a continuation of Bruin's Highway. It 

 occurs to us that the pathway may be a short way homeward, and 

 that at the same time work may be done. Windfalls, brushwood, 

 and a doubtful path make our way both difficult and tedious. We 

 reach a swamp where our guiding brook takes its rise. Conse- 

 quently our guide is gone. Alone, apprehensive of approaching 

 night, and the unwelcome society of bruin, we proceed. 



At length another brook appears flowing in an easterly direction ; 

 we suspect that it is Arisaig brook ; we are assured, and following 

 its friendly guidance, we ere long emerge from the thicket, reach 

 the familiar road of section (8), and consider that all is right. 



Knoydart Brook. 

 In the Arisai"' mountains — on the table land south of the mouth 



