402 C. CALLAWAY ON THE NEWEK GNEISSIC 



is too much covered in to promise good results ; but we come again 

 to the Assynt series in the prominent peak of Craig-na-faolin (934 

 ft.), which overhangs the south end of the loch. The upper half 

 of the western escarpment is formed of Arnaboll gneiss, very horn- 

 blendic, about 300 ft. thick, passing up into gneiss of the ordinary 

 Hope type. Dipping to the E.S.E., below the gneiss is the Anne- 

 lidian Quartzite. A little further to the south the quartzite opens 

 out on the strike, and Brown Flags come in between two bands of it. 

 This is no case of thinning-out ; for the flags appear suddenly, and, 

 instead of lying conformably with the quartzite, they are squeezed 

 into a double fold like an upright letter S very broad for its height. 

 The quartzite both above and below the flags is full of the worm- 

 burrows. The section is not very clear ; but the facts, so far as they 

 go, harmonize with our previous sections. The Quartzite, folded 

 back upon itself, has caught a mass of the Flags and squeezed it 

 into complex folds. 



Ground between Ben Arnaboll and Ben Heilem. — North of the 

 road from Heilem to Hope Ferry, and west of the Hope river, the 

 rocks are all of the Assynt series. Quartzite, flags, and dolomite 

 occur over and over again and in varied order, as if we had half a 

 dozen similar successions thrown pell-mell together. I gave some 

 study to the area, but concluded that, after the clear sections 

 further south, it would not be a profitable use of time to attempt to 

 unravel the confused tangle of faults, folds, and overthrows. 



Ground between Hope Ferry and W kitten Head. — The river Hope 

 forms the eastern boundary of the Assynt rocks as far north as its 

 mouth ; but at this point the Quartzite crosses over to the north- 

 east, and usually occupies the shore right along to Whitten Head, 

 nearly six miles north of the ferry. 



Where the Quartzite first appears, north of Inverhope, it apparently 

 dips easterly under Arnaboll gneiss. The uppermost beds are of the 

 seamy type, while the underlying strata at the shore are full of 

 worm-holes. Hence there would seem to be an inversion, as in the. 

 southern localities. 



A mile further north, in Cnoc-na-goar, the quartzite (which dips 

 to the E., as if below the gneiss) is the lower band. Following it 

 down to the shore-cliffs, we find the dip becomes progressively 

 lower ; and just at the sea-level the beds roll over to the W., form- 

 ing an anticline. At least this was the appearance from the top 

 of the precipice to the south ; but the nature of the ground prevented 

 a close examination. The same cause rendered it impossible for me 

 to ascertain the intimate structure of the rock ; but the beds are 

 apparently on the strike of the Annelidian Quartzite near 

 Inverhope. 



Two miles further north, near Fresgill, the Annelidian Quartzite 

 occupies the shore, dipping easterly at a low angle. Large blocks 

 of the Brown Flags are scattered about ; and, as they are unrounded, 

 they cannot have travelled far. There are no other signs of this rock, 

 so far I know, in the locality, or, indeed, anywhere north of Hope 

 ferry ; so that perhaps it would be hardly rash to suggest that the 



