138 Rev. A. Sedgwick and Mr. Murchison on Deposits contained between 



southern part of the county, have ah'eady been noticed in the introductory 

 part of this paper. It consists essentially of fragments, more or less rounded, 

 of the nearest primary rocks, but never contains any substance resembling- the 

 Caithness schist and sandstone. Thus, in the hills of the interior, between 

 Dunbeath and Braemore, it contains much quartz rock like that of the adjoin- 

 ing Scarabins, granite like that of the Ord, gneiss, micaceous slate, &c. &c. 



With the exception of the masses in almost immediate contact with the 

 primary rocks, it is generally held together by a red-coloured cement, which 

 is more or less siliceous; and the finer and coarser varieties frequently succeed 

 each other in regular beds ; so that we may meet with finely foliated red sand- 

 stone alternating with the very coarsest varieties of the conglomerate. In this 

 way the dip is easily ascertained, and is not generally greater than that of the 

 superior schists, except in the immediate vicinity of the primary rocks. Thus, 

 in the narrow valley which separates the Scarabins from the Maiden Paps, 

 the conglomerates dip at 45° towards the great northern plain ; but, at the 

 Schmian, which is further removed from the central quartz rock, the dip of 

 the same conglomerate system is in the same direction, but not more than 

 10° or 12°. 



That this conglomerate system forms the lowest part of the secondary de- 

 ])osits is evident, from its position and range in the county, compared with 

 the general dip of the beds which descend into the great northern plain. For 

 example, in ascending from Dunbeath towards the higher part of Braemore, 

 the beds of hard, siliceous flagstone rise toward the interior, and, in some places, 

 pass into a hard, thin-bedded, red, micaceous sandstone. From beneath this 

 series, and at the same angle of inclination (10° or 12°), rise, in succession, 

 beds of red conglomerate, containing a few subordinate beds of red sandstone, 

 by which we are led, in regular descending geological order, to the great 

 mountain masses of the Schmian and Mor-Bheim. The same facts present 

 themselves in ascending from Berridale up the denudation of the Langwell 

 river. 



Independently of all this evidence, and of the analogy presented by the 

 section of Port Skerry (which may, however, be considered of less importance, 

 inasmuch as the conglomerate has there degenerated into a comparatively 

 thin mass), the coast section between Berridale and the Ord seems to place 

 the true relations of the deposits here described beyond the reach of doubt. 

 The conglomerate system, as before stated, clasps round the Scarabin Hills, 

 so that a part of it ranges on the north side of that chain, and, passing under 

 the Caithness flagstones, does not appear upon the coast; with the exception 

 of one protruding mass at Borgue Head, which is seen in the cliff in the 



