﻿Vol. 66.~] FOLDS IN THE SCHISTS OF THE SCOTTISH HIGHLANDS. 611 



in no section a single isolated plane, and where its western out- 

 crop is exposed on the Ballachulish shore of Loch Leven, about a 

 mile west of Ballachulish, it is so conspicuously double that its 

 position on the map has been indicated by two close-set parallel 

 lines. Some 40 feet of the grey portion of the Ballachulish 

 Limestone occur sandwiched in between the two planes of the 

 slide thus separately shown. On the north-west the limestone is 

 bounded by the banded edge of the Leven Schists and Glen Coe 

 Quartzite (7 & 8), and on the south-east by the Striped Transition 

 Series (4') of the Appin Quartzite. 



The gape of the Ballachulish Core is particularly wide in this 

 neighbourhood, extending south-eastwards from the double slide 

 .just described to Sgorr a' Choise, a distance of about 3 miles. It is 

 also highly complex, including three minor folds — the Beinn Bhan, 

 the Gleann an Fhiodh, and the Sgorr a' Choise synclines. In the 

 case of each of these three folds the pitch is so steep that it gives 

 no clue in regard to the synclinal structure shown in Sections 

 F&G(P1. XLIV). Fortunately, however, the complementary fold 

 separating the Beinn Bhan and the Gleann an Fhiodh synclines is 

 cut obliquely across in Sgorr Dhearg, where its anticlinal structure 

 is revealed as clearly as can be desired in the face of a cliff. 



The anticline just mentioned brings up the Ballachulish Slates (5) 

 in full force from beneath the Striped Series (4'). Thus a striking 

 •contrast is furnished between the two sides of the Beinn Bhan 

 syncline : for, as already indicated, on the north-west side of this 

 syncline the black slates are entirely absent, and the Striped 

 •Series (4') comes into direct contact with Ballachulish Limestone (6) 

 across one of the two main branches of the Ballachulish Slide. 



The disappearance of the Ballachulish Slates against the 

 -Ballachulish Slide at this point (PI. XLIV, Sections F & G) is, 

 of course, merely a continuation of what has been described to 

 the north of Loch Leven (Section E). It may advantageously be 

 •compared with the disappearance of the Leven Schists against the 

 Fort William Slide (PI. XLIII, Section C). 



In its northern development the anticline separating the Beinn 

 Bhan and Gleann an Fhiodh folds is an essentially symmetrical 

 structure, throwing off on either side the Striped Series (4'), the 

 Appin Quartzite (4), the Appin Limestone (3), and the Appin 

 Phvllites (2) (cf. Section F in PI. XLIV, with the map, PL XLII). 

 Farther south, however, the south-eastern limb of this anticline is 

 in part replaced by a slide which successively cuts out the Striped 

 Series (4'), the Appin Quartzite (4), and the Appin Limestone (3). 

 A glance at Section G shows that this slide (S') is precisely homo- 

 logous to the Ballachulish Slide (B.S.), since it occupies the same 

 position in regard to the Gleann an Fhiodh syncline as the Balla- 

 chulish Slide holds with respect to the Beinn Bhan syncline farther 

 north-west. 



The next important slide encountered (S", Section G) forms 

 the south-eastern boundary of the Gleann an Fhiodh syncline. Its 

 presence is very clearly manifested in an attenuation of the Appin 



