CRUISE IN LOCH FYNE, JUNE, 1899, 377 



On the Clyde this fault is seen at Toward, Kilcreggan, Rosneath, 

 and Ardencaple, and it was crossed near Callander on the Society's 

 excursion on the Spring Holiday this year, and in the train on the 

 excursion to Aberfoyle on 24th June. 



The outcrops of the various groups of strata along Loch Fyne run 

 in the same direction as the anticlinal axis. The Geological Sur- 

 vey Memoir (p. 85) gives the succession as follows, but we take it 

 from the mouth of the loch upwards, the reverse of their order — 



1. "Albite schists, schistose greywackes, and other mica- 



schists." 



2. Green-coloured schists mixed with schistose greywacke and 



other mica-schists. 



3. The Glendaruel or Loch Tay limestone, a coarsely-crystalline 



marble, and calcareous quartzite. 



4. "Alternations of thin -banded mica-schists, commonly 



garnetiferous, with some limestones and ' green beds.' " 



5. " Graphite schists, dark graphitic limestones and quartzose 



schists intermixed with phyllitic garnetiferous schist." 



6. Ardrishaig phyllites, soft calcareous sericite schists, with 



many outcrops of quartzite schist and some limestones. 



These groups represent a downward succession of strata, but 

 which is the oldest and which the newest is not certainly ascer- 

 tained. On the Loch Fyne side of the anticline the north-west 

 rocks appear to be the newer, but on the Clyde side the south- 

 west rocks seem to be the more recent. 



To Group No. 1 belong the first four islands which we visited — 

 Sgat Mohr, Eilean Buidhe (buie), Eilean Buic, and Caisteal 

 Aoidhe. We did not land on any part of the regions where the 

 next two groups occur — namely, " the green beds " and 

 the Loch Tay limestone. At the Society's excursion to 

 Killin, already mentioned, several sections of rocks near 

 the head of Loch Tay, and in Glen Dochart, near the 

 head of Glen Ogle, were examined, showing the Loch Tay 

 limestone overlying hornblende schist. Regarding Cowal, Mr. 

 Clough, in the Memoir (p. 45), says — " The Glendaruel or Loch 

 Tay limestone is perhaps the most readily mapped and best- 

 defined schist in the district." . . . " It is seldom seen without 

 a band of hornblende schist either in or just at the sides of it, or 

 in both positions." 



