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PROCEEDINGS OE THE GEOLOGICAL SOCIETY. 



[Feb. 6, 



sures of the rocks, is that from the wild headlands of Arisaig to 

 the entrance to the Great Glen at Banavie. At Arisaig we found the 

 quartzose flagstones with a W.N.W. dip, traversed by innumerable 

 greenstone dykes having a north-westerly direction. The same 

 direction of dip continues along the road a mile and a half to the 

 east of the village of Arisaig *. The strata are then reversed to the 



Fig. 18. — Section of Rocks on the Roadside at the 7th Milestone 

 west from Tomdoun Inn. 



S.E. for about half a mile, after which they undulate in both direc- 

 tions, as is well shown along the crags near Borrodale, on Loch na 

 Nuagh. Dykes of greenstone with a N.W. strike still abound. At 

 the head of Loch na Nuagh the strata of micaceous quartzose schist 

 have a S.E. dip at high angles. This inclination continues to near 

 Loch Aylort, where the beds are vertical, sometimes leaning to the 

 one side, sometimes to the other. "Where the road descends upon 

 that arm of the sea, the dip is south-easterly ; but it is immediately 

 reversed to the north-west. From the point whence the road 

 diverges from the loch, the vertical and contorted strata are seen to 

 be convoluted in rapid arches ; after which, on again reaching the 

 sea-margin, the dip is south-easterly. 



At Kinloch Aylort, highly micaceous quartzose rocks, in well- 

 marked vertical beds, strike N. 10° E., which exactly resemble those 

 of Loch Hourn, showing the same alternation of grey quartzose 

 bands with others strongly micaceous, but without the admixture 

 of felspar. They are in places true mica-schists, in others quartz- 

 rocks. The glaciated surfaces are here very apparent, — the vertical 

 strata being smoothed and deeply grooved across their truncated 

 edges ; the direction of the groovings runs W. 30°-40° S. 



About a mile and a quarter from Kinloch Aylort the schists are 

 overlain by a band of quartzose flagstone, well bedded, and in some 

 beds micaceous and fissile. The dip is exposed in a quarry by the 

 roadside, being E. 30° S. at 77°. 



From this point onward to the head of Loch Ailt, another series 

 of micaceous quartzose schists occurs. The inclination is at high 

 angles, often vertical. The strata are sometimes beautifully con- 



* This is the Clanrarmald country, now possessed by Mr. Dukinfield Astley. 



