﻿1861.] 



HAKKNESS HIGHLANDS AND N. IRELAND. 



259 



thering t'o a purple colour, and with gneissose layers intercalated 

 in it. This latter mass is conformable to the limestone ; and, pass- 

 ing upwards into regular mica-slate, it forms the hills which lie 

 N.W. of Leny lime-quarry. On the road from Callender to Loch 

 Lubnaig, at Woodend, about half a mile from Kilmahog toll-bar, 

 quartz -rocka, similar to those of Leny Glen and having the same 

 inclinations, appear. The succeeding black shales and limestones 

 are not seen, being masked by debris, but the overlying purple 

 shales occur, passing into gneissose rocks ; and these are intersected 

 by a trap-dyke, termed locally " Blue Whin," at Woodhead Quarry. 



The arrangement of the rocks forming a portion of the southern 

 boundary of the metamorphic masses of the Highlands, as seen in 

 the neighbourhood of Callender, is exhibited in fig. 1, and is as fol- 

 lows : — First and lowest, quartz-rock, a small portion only of which 

 is exhibited ; second, black shales ; third, thin grey limestones ; 

 and fourth, clay-slates (shales) passing into gneissose rocks. 



Beyond the Woodhead whin-quarry we have a considerable 

 development of that form of metamorphic rock to which the name 

 chloritic schist has been applied, but of which the term " chloritic 

 gneiss of a fine grain " more fully expresses its nature ; and this 

 rock continues with the same N.W. dip to Anneehaugh, about three 

 miles from Callender, where it is intersected by another trap-dyke 

 containing red nodules. North of this dyke the same chloritic gneiss 

 is seen dipping in the same direction, but at angles varying from 

 40° and upwards, until we reach Ardchullarie, where another trap- 

 dyke makes its appearance ; and to this the name " Black Whin " is 

 applied. These trap-dykes produce very little effect on the dip of 

 the metamorphic rocks. After leaving Ardchullarie, we find that 

 northward the strata become much disturbed, and show a dispo- 

 sition to assume S.E. dips. At Creggan, about half a mile north of 

 Strathire village, this S.E. dip is very apparent. At Buskin Burn 

 another trap- dyke occurs, and also a vein-like mass of limestone 

 very thinly overlain by gneiss, the latter dipping N.E. There is a 

 considerable amount of disturbance in the strata here, and northwards 

 this disturbance also prevails. This mass of gneissose rocks occur- 

 ring in the area between the hills of Leny and Loch Earn, and 

 which possesses a great thickness, overlies the limestones of the 

 southern margin of the Grampians ; and, notwithstanding its flexures 

 and contortions, clearly arranges itself as a synclinal axis in the 

 neighbourhood of Strathire village, from underneath which we have 

 limestones making their appearance at Leny on the S.S.E., and at 

 Buskin Burn on the N.N.W. The mode of arrangement of the 

 rocks in this interval is shown in fig. 1. 



§ 3. Section from Loch Earn to Loch Tay (fig. 2). — At the N.W. 

 end of Loch Earn, at Dall, a considerable mass of limestone, having 

 somewhat of a gneissose aspect, and exhibiting itself in great thick- 

 ness, is seen. This limestone at this locality is nearly horizontal ; 

 but at the east side of the quarry, where it has been wrought, it 

 inclines at a low angle towards the E.S.E., and is succeeded by 

 chloritic gneiss. Near the seventh milestone from Iullin, at Loch 



