370 



C. CA.LLAWAY ON THE NEWEE GNEISSIC 



Fig. 3. — Section on Poulan-drein. (Scale 3 inches to 1 mile.) 



w 



e* c 4 V 



the right bank the uncertainty is removed. The Brown Flags, in 

 curved overthrown beds, are succeeded, after an interval of a few 

 yards occupied by drift and fragments, by the quartzite which we 

 traced along the scarp, dipping to the S.E. at 5°. This quartzite is 

 full of the " worm-holes ; " and similar rock can be traced up Poulan- 

 drein for over a mile, and over the south-eastern slopes of Cnoc-an- 

 drein to the very summit (over 1500 feet). 



Prof. MiaH, F.G.S., Mr. Tiddeman, F.G.S., and Mr. Eccles, F.G.S., 

 visited this section under my guidance ; and they all agreed that 

 there was an overthrown syncline, with a fault beyond ; but they 

 were not sufficiently familiar with the district to express an 

 opinion on the age of the quartzite east of the fault. 



In this section we see that the Assynt group forms a synclinal 

 fold thrown back upon itself ; while quartzite, perfectly resembling 

 the Annelidian Quartzite on the west side of the syncline, appears to 

 the east in nearly horizontal beds. The natural interpretation of 

 these facts is, that the underlying quartzite has been brought up 

 along a line of dislocation and crush, and pushed laterally to the 

 west, bending back the dolomite and flags. The upthrow cannot 

 be great, the place of the Annelidian Quarzite being immediately 

 under the Flags. 



Quartzite of Cnoc-an-drein. — I have said that the Annelidian 

 Quartzite at the Poulan-drein fault can be traced without a break to 

 the summit of this mountain. Going down from the summit over 

 the north-western scarps towards Calda Burn, we pass over a de- 

 scending series, till at the burn we reach the quartzite with red 

 felspar bits. But this quartzite may be traced down the burn till 

 it seems to overlie the Dolomite, as in the section described. In 

 other words, on Calda Burn the Dolomite is conformably (!) succeeded 

 by beds which are from 100 to 200 feet lower in the quartzite series 

 than the strata which conformably (!) overlie the Dolomite in Pou- 

 lan-drein ! 



