104: ME. E. B. BAILEY OX THE STEUCTrEE OF _Vol. Ixxviii, 



The secondarT folding of the Iltay Xappe has been mentioned 

 on several occasions already (fig. 1). One main featm-e is the 

 synclinal fan of Loch Awe followed in relay by that of Ben Lawers. 

 South-east of this lies the Cowal Anticline oveilm-ned (north-east 

 of Abei-foyle) south-eastwards. On the north-west lies the Islay 

 Anticline, overturned north- westwards in connexion with the Loch- 

 Skerrols Thrust. It is important to reahze that the relationship 

 of the Loch-SkeiTols Thrust to the Islay Anticline shows almost 

 certainly that this particular thrust is of rather late date in 

 Southern Highland history ; and also that it originated during a 

 phase of north-westward movement. There is additional and quite 

 independent evidence for the inferred north-westward movement. 

 The nature of the foundation which emerges from beneath the 

 Loeli-Skerrols Thrust is such as to suggest a correlation bet^veen 

 this important dislocation and the Moine Thiaist of Eoss and 

 Sutherland (1917. fig. 3, p. IBS; ; and it is well known that the 

 displacement along the Moine Thrust has been directed towards 

 the north-west (pp. 88 ct 90). 



The Ballappel Foundation. 



Constitution. — The Eilde Flags are one of the most im- 

 portant sti-atigraphical units of the Ballappel Foundation. For 

 reasons already explained (p. 94). certain rocks situated on a 

 lower structural level than the Eilde Flags of the Loch-Eilde Mor 

 outcrop are classified in PI. I as constituents of a Sub-Eilde 

 Complex. In a stratigraphical sense the rocks of the Sub-Eilde 

 Complex are incerice sedis. Their cover, however, can bearrano-ed 

 in sequence as follows (1910 r/, 1912 h, 1911. 19161 ;— 



Eilde riags (commonly classed with the Moine Gneisses of the Central 

 Highlands). 



Quartzite and 3Iica-Schist assemblage including two certain 

 members, the Glen- Coe Quartzite and the Leven Schists (Mr. E. G. 

 Carruthers argues for six instead of two subdivisions, see p. 9-i). The Glen - 

 Coe Quartzite is fine-grained, except that near the head of Loch Creran 

 and in Glen Strae it cari-ies conspicuous pebbles. The Leven Schists are 

 greenish-grej mica-schists (or phyllites) with a marked tendency to lamina- 

 tion. They are often somcAvhat garnetiferous, and in the districts of Glen 

 Spean and Glen Etive they are i-ich in pseudomorphs aft^r actinolite. A 

 feature of the group is the Banded Series, which connects the more pelitic 

 portions with the Glen-Coe Quartzite ; in this Banded Series, quartzose beds 

 are very common, while black graphitic seams and calcareous lenticles are 

 generally to be found. The Banded Series is. as a rrde, subordinate in bulk : 

 but it assumes immense proportions about the head of Loch Creran. and 

 thence north-eastwards towards Loch Etive. 



Ballachulish Limestone, of which there are two main subdivisions — 

 (1) bands of cream-coloured limestone at the margin of the Leven Schists 

 followed by pale-grey, more or less calcareous mica- schist, often highly 

 quartzose, and (2) a dark-grey or black, relatively pure limestone at the 

 margin of the Ballachulish Slates. 



Ballachulish black graphitic and pyritous Slates. 



Appin Striped Transition Series. 



Appin Pebbly Quartzite. 



