Vol. 69.] LOCH AWE SYNCLINE (aRGTLLSHIRE). 28T 



On such evidence as this — and it is repeated elsewhere in the 

 neighbourhood — it appears justifiable to recognize the ' lavaform ' 

 epidiorites of Loch Awe and its vicinity as true lavas. This 

 opinion is greatly strengthened by another circumstance which 

 became apparent during my visit. There are numerous more or 

 less conglomeratic beds associated with the lavaform epidiorites 

 of the Loch Awe district, and in several cases they contain 

 fragments of epidiorite of lavaform type. As this is a 

 very important point, I shall illustrate it by citing in the following 

 section a few examples of which I have taken definite record.. 

 Reference to similar occurrences, already recognized by Dr. Peach 

 in the neighbourhood of Tayvallich, will be found in the Strati- 

 graphical Appendix, § VII, p. 304. 



III. Epidiorite-Fragments in Conglomerates near Loch Awe. 



Mr. Hill has mapped a conglomerate or conglomeratic series 1 in 

 the district between Glen Aray and Loch Awe. I examined 

 very carefully the wide exposure that occurs halfway across between 

 the valley and the loch. The conglomeratic beds have a dark 

 matrix, which may be either siliceous or slaty, and sometimes 

 gritty with quartz- and felspar-grains. The most conspicuous 

 pebbles, ranging up to a foot or more across, consist of pebbly 

 quartzite or grit, and present a water-rounded form with little 

 deformation. They had evidently hardened before they were made 

 into pebbles. With these are associated a great number of 

 small flattened fragments of epidiorite. It takes a good 

 deal of searching to find large lumps, in the light of which the 

 smaller pieces can be interpreted with confidence ; but such do 

 occur here and there — some of them very slaggy, and recalling at 

 once in their appearance the pillow-lava series. The epidiorite- 

 pebbles are much more deformed than those made of quartzite. 



On the north-western shore of Loch Awe, opposite Inn is Stuire 

 (the island through which the line of section AB, PI. XXXII, 

 passes), the evidence is less certain. A conspicuous outcrop of pure 

 banded black limestone is followed towards the lake by thin gritty 

 limestone, containing big pebbles of quartz and pure limestone. 

 Next comes a thin bed of breccia, exactly like the gritty limestone, 

 save for the addition of very numerous fragments of a pale rock 

 which is apparently epidiorite. This breccia is succeeded by 

 a strong outcrop of gritty limestone, containing fragments of pure 

 limestone, on the extreme shore-line. Finally, there is pebbly 

 quartzite. 



Recrossing Loch Awe, one meets with the following section at a 

 lime-kiln, a quarter of a mile due south of Fincharn Castle, 

 which stands on the shore opposite Inverliver. The rocks are 



1 This is the only one of the conglomerates, now dealt with, that it has- 

 been found practicable to show in the map, PI. XXXII. 



