'294 me. e. b. bailey on the [June 1913, 



associated lavas, clearly overlies the Quartzite Division, -with its 

 intrusive sills : — 



' The rocks of the area are sharply folded, in the manner usual in the region, 

 about axes trending north-north-east and south-south-west, so that the order 

 of superposition of the beds is only made apparent owing to a marked pitch of 

 the axes of the folds towards the south-south-west in the northern part of the 

 area. The Quartzite Group is thus carried to the southward underneath the 

 overlying slates, limestones, and volcanic rocks, which cross the peninsula 

 from the Sound of Jura inwards to the Linnhe Mhuirich l in the form of an 

 escarpment facing the north, complicated by minor folding.' [18, pp. 65-66.] 



(6 b) The Crinan Quartzite is less strongly developed in the 

 north-western portion of the Loch Awe Syncline than elsewhere, and 

 5ome of the mapping north of Kilchrenan may be open to criticism, 

 especially as the ground is locally obscured by Glacial deposits. 

 Still, I have satisfied myself as to the essential accuracy of 

 .Mr. Kynaston's mapping in this locality, and have found inde- 

 pendent evidence for a descending structural sequence from the 

 Tayvallich Division right down to the Ardrishaig Phyllites. Mr. 

 Kynaston has traced a conglomerate — which may be confidently 

 correlated with the Glen Aray Conglomerate already described — in 

 a curved outcrop past Kilchrenan, across the general strike of the 

 folding, down to the shores of the loch. The exposures are dis- 

 continuous, it is true, but there can be no doubt that they all belong 

 to a single horizon. On the south is an expanse of epidiorite, from 

 beneath which the conglomerate emerges, owing to an obvious, 

 •though gentle, south-westerly pitch.* On the north and west is a 

 tract of black slate and limestone, sometimes pebbly. All these 

 sedimentary rocks, including the conglomerate, evidently belong to 

 the Tayvallich Division, although the stratigraphical simplicity is 

 marred to some extent by the local presence of a strong intercalation 

 of pebbly quartzite occupying part of the interval between the 

 conglomerate and the first important limestone. Beyond, again, is 

 a belt of scattered quartzite -exposures, representing, I take it, the 

 Crinan horizon. This belt is in turn limited by a limestone out- 

 crop, or series of outcrops, which certainly must be referred to the 

 Shira position, and as certainly overlies the Ardrishaig Phyllites of 

 the slopes overlooking the loch. 



(6 c) In the previous paragraph it has been noticed that the 

 Shira Limestone and other members of the Loch Awe Group clearly 

 overlie the Ardrishaig Phyllites on the north-west side of Loch 

 Awe. This feature is extremely well shown again in the country 

 -on the opposite side of the loch. It has already been stated that 

 the recognition of this important structural relation, the super- 

 position of the Crinan Grits and Shira Limestone upon the Ardri- 

 shaig Phyllites for miles across the general strike of the folds, is 

 probably responsible for Mr. Hill's belief in the existence of the 

 Loch Awe Syncline. 



1 The western arm of Loch Sween. 



2 The agreement of this evidence with that already adduced in regard to the 

 . structural position of the Loch Avich Slates and Grits is complete. 



