﻿Vol. 66.^ SCHISTS OF THE SCOTTISH HIGHLANDS. 607 



In the eastern outcrop of the lower limb of the Ballachulish 

 Fold, repeated by the syncline, the attenuation of the limestone 

 is equally apparent in all sections. In most exposures of this 

 outcrop, however, there is no chance of distinguishing Ballachulish 

 Slates belonging to the lower limb from those belonging to the 

 upper limb, until, close to Loch Leven, the taper end of the core of 

 the Appin Quartzite peeps through ; the quartzite here rests 

 directly upon the diminished representatives of the Leven Schists : 

 that is, at this point, both limestone and slate have been cut out 

 entirely by the Ballachulish Slide (Section E, PI. XLIV, shows 

 this relation continued to the southern shore of Loch Leven). 



The phenomena attendant upon the attenuation of the Leven 

 Schists in connexion with the Ballachulish Slide are perhaps even 

 more instructive than those just recorded with respect to the 

 Ballachulish Slates and Limestone. On the north-west of the 

 outcrop of the Ballachulish Core lies a thoroughly well-exposed 

 anticline of Glen Coe Quartzite, forming Tom Meadhoin (fig. 4). 

 The quartzite here is separated from the limestone, black slate, and 

 pebbly quartzite of the Ballachulish Core by a mere fringe of Leven 

 Schists, in one extreme case (PI. XLIII, Section D) reduced to 30 

 feet in thickness. In spite of this, the same Leven Schists, where 

 they sweep round the nose of the Tom Meadhoin anticline, occupy 

 the surface of the country on the north-west for an uninterrupted 

 distance of a mile, and build mountains measuring 2000 feet in 

 height from base to summit. Clearly, if there were no other 

 evidence, we should still have to postulate a slide along the south- 

 eastern margin of the Tom Meadhoin anticline to account for so 

 great a discrepancy. 



A glance at Sections D-F (Pis. XLIII & XLIV) shows that the 

 Tom Meadhoin (Doire Ban) fold of Glen Coe Quartzite, closing to 

 the north-west under the Ballachulish Slide, is the precise comple- 

 ment of the Appin fold of Ballachulish Limestone, etc. (PI. XLIII, 

 Section C) closing to the south-east above the Fort William Slide. 



The Ballachulish Slide traced from Loch Leven to 

 Allt Coire an Easain. — Crossing Loch Leven, we find that 

 the two outcrops of the Ballachulish Slide begin to diverge widely. 

 The eastern outcrop sweeps up Glen Coe, following round the nose 

 of a steeply pitching anticline of Glen Coe Quartzite (PI. XLIV, 

 Sections E & F), and only separated from the latter by the 

 banded portion of the Leven Schists. This banded series (part of 

 Group 7) is overlain directly by the Ballachulish Slates (5), except 

 at the shore, where a thin band of Appin Quartzite (4) inter- 

 venes (PI. XLIV, Section E). 



The Ballachulish Slates dip south-westwards beneath a thick 

 mass of Ballachulish Limestone, evidently much reduplicated by 

 folding (Section F), and this in turn passes beneath a still thicker 

 covering of Leven Schists extending away towards Glen Creran 

 and Glen Etive. Farther up Glen Coe, beyond the boundary-fault 

 of the cauldron subsidence, these overlying Leven Schists are 



