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PKOCEEDINGS OP THE GEOLOGICAL SOCIETY. 



[Feb. 6, 



quartz-rocks into a quartzose flaggy series, seem to us facts which go 

 far to prove that this " serpentine or felspar-porphyry" is in reality 

 a highly metamorphosed band of felspathic grit, — the superior degree 

 of metamorphism being due to the existence of the limestone, and 

 possibly also to the large amount of felspar in the original rock. 



It may be noticed in passing, that along the sides of Loch Broom 

 the exposed surfaces of rock are usually well rounded, smoothed, 

 and scratched, the strise running parallel to the direction of the 

 fiord, i.e. N.W. and S.E. 



From Ullapool the road skirts the shore to the head of the loch, 

 and abounds in natural as well as quarried sections of the strata. 

 The quartzose flaggy schists which overlie the metamorphosed band 

 and the limestone have a steady dip towards the south-east, of about 

 15° or 20° ; sometimes, however, as about four miles south from 

 Ullapool, they rise to 50° or 60°, but immediately subside again to 

 their wonted gentle angle. At Fascrianach, about eleven miles from 

 Ullapool (the first stage on the road to Dingwall), there is an 

 admirable section both along the wayside and in a deep narrow 

 gorge on the west side of the road. The strata here are micaceous 

 quartzose flagstones, many of which seem hardly at all altered ; 

 indeed, we instinctively broke open the fissile plates, half hoping to 

 find between them some fucoid or other impressions. The dip is on 

 the whole south-easterly, at angles of not more than 3° or 5° ; but 

 the beds are here in slight undulations. 



At the eleventh milestone the beds are in places irregularly lami- 

 nated, and split with a tough, uneven, gneissose fracture. They 

 are penetrated by irregular veins of white quartz, which run slightly 

 oblique to the planes of bedding, though in a general sense parallel 

 to them. But even these irregularly foliated bands are both under- 

 lain and covered by the usual fissile finely-laminated flagstones, 

 where the layers of stratification are as parallel and unbroken as in 

 any freestone-quarry among the Carboniferous rocks of the south. 



At the branch-road to Dundonald the flaggy beds become darker 

 and more gneissose, and begin to assume a contorted aspect. The 

 dip, too, increases, and eventually becomes vertical. We crossed the 

 great Dirry More to Contin ; but over the greater part of this wild 

 region the rocks are wholly obscured. It appeared to us, however, 

 that the gneissose beds at the Dundonald road, after being crumpled 

 and contorted in a synclinal axis, probably rise again with a north- 

 westerly dip. It seems almost certain, at least, that between that 

 locality and Ben \Vyvis there must be many archings, like that on 

 Loch Fannieh before described*, so that the same group of rocks is 

 repeated again and again ; but even then the actual thickness of this 

 upper quartzose and gneissose series must be admitted to be very great. 



Beturning to Ullapool, we shall now describe the course of the 

 lower quartz-rock, limestone, and upper quartzose series towards 

 the south. 



From Loch Broom to Loch Maree. — The region between Loch 

 Broom and the head of Loch Maree is one of the wildest in the 

 * Quart. Joum. GepL Soc. vol. xv. p. 387. 



