Vol. 69.] LOCH AWE SYNCLINE (aEGYLLSHIRe). 283 



which at once suggested that Dr. Peach's discovery would have 

 a wide application in the northern part of the region. Extracts 

 from such passages as hear upon this point are given below. 



In 1897 Mr. Kynaston noticed that certain ' epidiorite sills,' 

 not very far from the northern end of Loch Awe, showed peculiar 

 structures which he attributed to mechanical deformation [6, p. 62]. 

 In these sills there are, he says, 



' numerous elongated and oval masses of the rock, around which the rest of the 

 mass appears to sweep with a kind of flow-structure on a large scale. The 

 whole section gives the appearance of gigantic " augen-structure." This is well 

 seen in the burn at Ardbrecknisb, 1 and again south-west of Kilchrenan.' 



Dr. Peach, whose attention was drawn to some of these ' augen ' 

 by Mr. Kynaston, has told me that he regards them as deformed 

 pillow-structures, an interpretation supported by photographs which 

 may be consulted in the Survey collection (numbered C 772-774).'- 

 Three years later Mr. Kynaston, in dealing with the same 

 district, actually divided the epidiorites into two classes, grouping 

 the more vesicular rocks among them as ' lavaform,' although he 

 still regarded them as intrusive [9, p. 34]. Among his lavaform 

 epidiorites are some, the description of which again suggests the 

 existence of pillow-lavas ; for we read that a 



' rock, seen to the south-west of Kilchrenan, forms hard, roughly spheroidal 

 cores, packed closely together in a dull fine-grained green schist.' 



In summing up, he says : — 



' We thus have varieties of the so-called " epidiorites," which in hand-specimens 

 and in thin slices under the microscope have every appearance of true lava.' 



It must be remembered that Mr. Kynaston left for South Africa 

 in the spring of 1903, the year in which Dr. Peach later on ob- 

 tained conclusive evidence of volcanic rocks south of Tayvallich. 

 Accordingly, Mr. Kynaston's description in the Geological Survey 

 memoir on the northern part of the district, published in 1908, was 

 written with the idea that, despite appearances, all the epidiorites 

 were really sills. We may note, however, that he supplies us with 

 an additional locality for what one may reasonably interpret as a 

 pillow-lava [16, p. 43]. After referring to a porphyritic vesicular 

 epidiorite 2 miles south-south-east of Portsonachan, that is, on the 

 eastern side of Loch Awe, about 3 miles south of Kilchrenan, he 

 goes on to say, 



' Not far from this locality there is a zone of rock, forming part of the same 

 mass, which consists of numerous lenticular patches of a highly amygdaloidal 

 rock embedded in a fine-grained greenish schistose matrix. . . . The rock has 

 strongly the appearance of a highly vesicular basic lava.' 



Farther south, about a quarter of a mile north-east of Loch a' 

 Ghille, which lies a mile and a half south-east of Loch Avich, 



1 East of Loch Awe, 2£ miles east-south-east of Kilchrenan. 



2 There is a very fine series of photographs, taken by Mr. R. Lunn, in the 

 Geological Survey collection, illustrating the geology of the Loch Awe district, 

 especially the Tayvallich peninsula. 



