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PROCEEDINGS OE THE GEOLOGICAL SOCIETY. 



[Feb. 6, 



flanks of the mountain-mass of Kealloeh — an enormous denuded 

 range of gently inclined Cambrian sandstones. 



Prom the head of the Corry Hourachan to the bealloch at the S.E. 

 end of Strath-na-Shallag, there is a broken track that winds among 

 a succession of knolls and crags, rising out of a bare moor. These 

 show well the character of the passage-beds of the quartz-rock into 

 the upper quartzose series. No igneous rock was observed in the 

 whole district ; and the metamorphic band of Loch Broom seems to 

 have died away. 



At the head of Strath-na-Shallag, a streamlet descending from 

 the east has laid open a good section of quartzose grit, argillaceous 

 shale, and gneissose bands, some of the strata showing annelide-bur- 

 rows. It seemed a hopeful locality in Avhich to look for fossils ; but 

 our time did not admit of a careful examination of the rocks. Lime- 

 stone was formerly worked here ; but the bed escaped our search. 



Ascending the valley of Loch Ned, a section occurs similar to that 

 of Corry Hourachan. The east side of the glen is capped by the 

 upper gneissose beds ; below these comes the quartz-rock, which in 

 turn rests on the Cambrian sandstones that occupy the bottom of 

 the valley, and rise up into the group of mountains lying between 

 Loch-na-Shallag and Loch Maree. As we ascend the valley, the 

 quartz-rock descends into the bed of the stream, and then begins to 

 ascend on the western side, stealing up the hillside, the inclination 

 of which nearly corresponds to the angle of dip of the beds. The 

 gneissose beds have been swept out of the bottom of the valley, but 

 they occur as outliers on the western side. Of this there is one 

 striking example a little above Loch Ned. The eastern slopes of Scour 

 Van slope down to that lonely tarn, and their lower parts are coated 

 with quartz-rock. A stream here descends in a series of cascades, 

 which, from the snowy tint of the quartz-rock and the sombre hue 

 of the Cambrian sandstones that form the higher grounds, are ren- 

 dered eminently picturesque. The watercourse for some way runs 

 on mclined planes of quartz-rock, above which, in distinct super- 

 position, are two dark peaks, outliers of a greenish serpen tinous 

 and actinolitic gneissose rock, witb veins of red felspar (fig. 7). The 



Fig. 7. — Section at Loch Ned. 



b. Cambrian sandstone and conglomerate. 



c. Qxiartz-rock. d. Gneissose schists. 



