286 



MB. E. B. BAILEY ON THE 



"June 1913, 



peculiarly difficult field of research, and that the results obtained 

 are often merely tentative. 



I may complete this notice, of the accounts so far published of 

 ■what I take to be the Tayvallich volcanic zone, with a reference to 

 another 



' porphyritic epidiorite, which resembles a deformed pillowy lava in which the 

 interspaces between the pillows have been infilled with sediment.' 



This last I found in 1905 on the shores of Loch nam Ban, east 

 of Loch Sween [15, p. 92]. Farther north, along the same line of 

 strike, vesicular epidiorites had previously been met -with by 

 Mr. Hill and Dr. Peach, and their distribution is such that the 

 Loch-nam-Ban occurrence is linked on with those of the Loch Awe 

 and Loch Avich region. 



Fig. 2. — Deformed pillow -lava, Rudha Cuillin, eastern shore of 

 Loch Awe, a mile and a half east of Inverliver. 



pillows ' are from 2 to 5 feet long.] 



It is clear, then, that by 1905 a large body of evidence had 

 accumulated, which was susceptible of the interpretation that 

 Dr. Peach's ' Tayvallich volcanic zone ' was widely developed in 

 the precincts of Loch Awe. It was, of course, highly desirable 

 critically to re-examine this old evidence in the light of the 

 new interpretation. An opportunity came with the publication of 

 Sheet 37 and its accompanying memoir [14], an event which 

 rendered the geology of the district accessible to the private 

 worker in an altogether new sense. This occurred in 1905, and in 

 the spring of 1906 I set out in my holida3 T -time to look into the 

 matter for myself. On the ground, the evidence seems conclusive. 

 The stream-section at Inveiliver furnishes a very clear exposure 

 of what, I think, must be regarded as a succession of vesicular 

 lavas ; while the shores of Loch Awe, not far away, exhibit the 

 two highly-typical examples of pillow- structure illustrated in 

 figs. 1 & 2 (pp. 285-86), which are exact copies of sketches made 

 on the spot. 



