1859. J MURCHISON NORTH HIGHLANDS. 227 



Now the overlying quartzose rock of Loch More passes gradually 

 upwards into a micaceous flagstone, which extends to the head 

 of the loch at Kinloch. This micaceo-quartzose flagstone (the 

 wide-spread "gneiss" of the maps), which, when fractured, is 

 of grey colour and very finely laminated, is essentially different in 

 structure, strike, and dip — in short, in every respect — from the old 

 or fundamental gneiss of Loch Stack, distant only five miles, — the 

 latter, as before said, dipping to the W.S.W., whilst these micaceous 

 flagstones overlying the limestone dip east. When, therefore, we 

 see in this very limited distance, that, besides the manifest litho- 

 logical distinction between the massive lower and highly crystalline 

 granitic gneiss and the superior flagstones, these two rocks have 

 utterly discordant strikes and dips, and that the Silurian quartz-rocks 

 and limestone arc regularly interposed between them (the uppermost 

 flaggy strata following conformably the quartz-rock and limestone), 

 the conclusion is irresistible. 



Whilst such is clearly the general ascending succession, it is at the 

 same time to be stated that the stratified rocks of this tract, bike 

 those of most other Highland districts, have been subjected to many 

 fractures and faults. Thus, Loch More and Loch Stack are sheets of 

 water that occupy the line of great faults transversal to the strike. 

 This phenomenon is clearly marked by the place occupied by the 

 limestone on the opposite banks of Loch More. On the north bank, 

 where in 1 858 I traced the limestone through the moss and moor, 

 the rock is slightly inclined only ; but on the south bank, as in the 

 section, fig. 6, it is very highly inclined. But these transverse dis- 

 locations serve only still more to support the conclusions arrived at, 

 since, notwithstanding their occurrence, the same order of succession 

 is seen on both sides of this broad loch which traverses all the suc- 

 ceeding strata which lie upon the fundamental gneiss. 



Additional observations on tJie tract of Durness. — This tract of 

 Lower Silurian limestone (c), so celebrated for its fossil contents, has 

 been subjected to so many dislocations, that in one line of. traverse 

 only, or that in which my former section* passed, can it be viewed 

 as unbroken. Though the lower quartz -rock, which dips away 

 from the Cambrian rock of Bcrishven, and occupies the western 

 side only of the Kyles of Durness, absolutely plunges under the 

 limestone, and is again brought up by a reversed dip against the 

 older gneiss of Ben Keannabin, uo other transverse section thus re- 

 presents a trough. On the contrary, the limestone is thrown abruptly 

 into contact with the old gneiss of Ben ELeannabin and Ben Spionnaeh 

 on the north-east, and constitutes a narrow wedge-shaped mass 

 between thai great fault and an equally huge one, which truncates 

 it against the old gneiss on the west side of the Upper end ni' the 

 Kyle of Durness. 



nor myself atlnrli importance to it. I slial] afterward-, -how that in other pi.i,-«-, 

 the protrusion of \a-t ma.-.-es of -ueh igneous roek does not break up or interfere 



with the continuous Buparpoeition of the Bedimentan strata 

 * Quart. Journ. Geo] Soc. rol sv. p. 864. 



