﻿148 



MR. E. BATTERSBT BAILEY ON 



[vol. Ixxii, 



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possible worm-tracks and rain- 

 (jj .-*■> pits. In the massive quartzite 

 iA m jg Dr. Peach records worm-pipes 

 W 42 | similar to the ' small pipes,' 

 'ordinary pipes,' and 'trumpet- 

 pipes ' characteristic of the 

 three zones of the 'Pipe-Rock' 

 of the Durness Quartzite. I 

 could not find these worm- 

 pipes during the time at my 

 disposal, and it must he re- 

 membered that structures sug- 

 gestive of worm-pipes are 

 sometimes open to a variety 

 of interpretations. I have seen 

 small, rounded, sandy bodies 

 interrupting the bedding of 

 the Islay Quartzite about 

 2 miles south-west of Beinn 

 Bhan (South Islay), which 

 strongly recall the choked 

 openings of worm-pipes ; but 

 I was never able to trace pipes 

 down from them into the rock 

 below. Similar 'small rounded 

 concretions on the weathered 

 surfaces ' of some of the 

 quartzite near the western 

 coast of Scarba have been 

 called ' pseudopipes ' by Dr. 

 Peach because of their 'simu- 

 lating the so-called " pipes." ' 



The Dolomitic Group clearly 

 dips off the Lower Quartzite 

 division in both sections along 

 the coast north of Portaskaig. 

 The more northerly exposure 

 is terminated by the Bona- 

 haven Fault. So far there is 

 no difference of opinion in 

 regard to the structure of the 

 coast, and the part of fig. 5 

 south of Bonahaven is little 

 more than a copy of a section 

 given in the Survey Memoir. 



The Bonahaven Fault intro- 

 duces the Upper Fine-Grained 

 Quartzite — a pure, slightly - 

 felspathic, well-bedded quart- 

 zite with vitreous fracture ; 



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