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PROCEEDINGS OP TIIE GEOLOGICAL SOCIETY. [Feb. 20, 



well seen, dipping N.N.W. at 35°, and is of a uniform light-grey 

 colour, with very distinct bedding and lamina?, and possessing litho- 

 logical features which very nearly ally it to some of the carboni- 

 ferous limestones. No traces of fossils, however, occur in it. At 

 Dunien, on its south side, trap appears. From Dunien eastwards 

 its course is well seen. It has been quarried at Balchraggan and 

 Soilairzie (at the latter place it has white lenticular bands of pure 

 carbonate of lime along the laminae) ; and from hence it extends 

 across Glen Shee by Mount Blair into Glen Isla. 



"With reference to Glen Shee, the valley being open and the 

 country on the hill- sides to a great extent clothed with heath, the 

 sections are not so satisfactory as in many other portions of the 

 Highlands. A dark-grey limestone was, however, formerly worked 

 at Balanzien, about two miles S. of the Spittal. The exposure here 

 is only imperfect, and the limestone apparently dips N. (?) On the 

 hill on the north side, a fine-grained grey syenite is seen. From 

 the Spittal, up Glen Beg, on the north side, great masses of red 

 porphyry manifest themselves ; but the same grey limestone of Bal- 

 anzien becomes again visible in the higher part of Glen Beg ; and, 

 from the verdant herbage on the S. side of the stream, this limestone 

 would appear well developed in this valley. At the spot on the 

 road-side where it has been wrought, its arrangement is irregular 

 and its dip indistinct. In the hill above this quarry on the N., con- 

 torted gneiss is seen with a N. inclination. From the section here 

 no definite conclusions can be arrived at concerning the relative 

 arrangement of the gneissose limestones and quartz-rocks. The 

 influence of the plutonic area, which commences on the S.W. of the 

 Ben-y-Gloe Mountains, and, extending eastward, unites with the 

 great granitic areas of Aberdeenshire, has so far broken up the several 

 mctamorphic rocks as to render their arrangement almost unintelli- 

 gible in the regions which lie immediately south of this plutonic 

 area. With reference to Glen Tilt, Macculloch alludes to the confused 

 arrangement which prevails in this valley among the strata. There 

 are, however, certain statements occiirring in his memoir (Geol. 

 Trans, vol. iii.) which lead to the inference that on the south side of 

 the Tilt the limestones " invariably " dip to the south at varying 

 angles (p. 305) ; and as regards the quartz-rocks of Ben-y-Gloe, 

 Macculloch remarks that these are seen alternating with limestones, 

 which are again succeeded by the mica-slate (p. 307). The follow- 

 ing statement also occurs : — " We have seen that the great mass of 

 quartz-rock is followed by a small bed of limestone, and that this 

 again is succeeded by micaceous and clay-slate, terminating the 

 series of the bedded rocks in this direction " (alluding to the south) 



(p. 312). . . , 



From the sections which have already been described, and from 

 the observations of Macculloch, it is evident that the sequence of 

 rocks from the margin of the quartz-rock area towards the southern 

 limits of the Grampians is as follows : — First and lowest, quartz- 

 rocks ; secondly, grey limestones, in some instances with lenticular 

 bands of white carbonate of lime. These limestones are of very 



