134 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 8, 



system of subterranean disturbance is seen, not only in the general 

 parallelism of the great synclinal and anticlinal folds and the faults 

 of the strata in Scotland, and the consequent position and features of 

 her mountain-ranges, valleys, rivers, and lochs, together "with the 

 outlines of her coasts and islands, but equally in the direction of the 

 strike of the outcrops of the long series of successive geological for- 

 mations in England. The facts of the existence and long con- 

 tinuance of this great system of disturbance, and the important results 

 produced by it, are now admitted by all geologists, whether they 

 regard such subterranean forces, with the late Sir Eoderick Mur- 

 chison and the Duke of Argyll, as the immediate cause of the physical 

 features of the country, or, with Professors Ramsay and Geikie *, as 

 only directing and modifying the really efficient and direct cause of 

 those phenomena — namely denudation. 



A review of the general position and relations of the strata of the 

 north-east of Scotland appears to indicate that, over the tract now 

 occupied by the Moray Firth, the Secondary strata were let down 

 among the Palaeozoic rocks by a series of parallel faults ranging 

 N.E. and S.W., and that, by the slow action of denuding forces, 

 the great mass of these strata has been removed, a few minute 

 patches alone escaping. The general form of this vast inlet and the 

 position of the peninsulas which project into it have been deter- 

 mined by these great faults ; and it is probable that extensive de- 

 posits of Secondary age still exist beneath its comparatively shallow 

 waters. 



To some the hypothesis contained in the foregoing pages may, at 

 first sight, appear startling — namely that, over large areas of the 

 Highlands, Secondary strata to the thickness of from 2000 to 3000 

 feet (not to notice the Cretaceous and Triassic rocks) once existed, 

 and that all of these, with the exception of a few minute fragments, 

 have been removed by denudation. But those who have seen how 

 many thousands of feet of apparently almost imperishable rocks, 

 like the Laurentian gneiss, the Lower Silurian quartzites, and the 

 Old Ped conglomerates, have evidently been removed over vast 

 areas in the Highlands, as indicated by the truncation of curved 

 strata and the position of outlying patches, will readily admit the 

 facility with which the same causes, under equally favourable con- 

 ditions, would have swept away the comparatively soft masses com- 

 posing the strata of the Secondary series. 



III. Description of the Series of Secondary Formations in the 

 North-east of Scotland. 



An admirable topographical description of the areas occupied by 



me that a portion of a Coccosieus, a characteristic fish of the Middle Old Red, 

 has recently been obtained from this isolated patch in Sutherland. 



* Professor Geikie considers that the fault which has thrown down the 

 patches of Oolite on the Boss-shire coast may be only a continuation of that 

 great dislocation which certainly traverses the line of the Caledonian Canal 

 (' Scenery of Scotland,' p. 177) ; if not continuous with, it is certainly parallel 

 to, that great fault. 



