and some other Stratified Deposits in the North of Scotland. 305 



is at present exposed in cutting drains^ but the surface of the whole is partially 

 covered by hillocks of diluvium. 



At the mouth of the Loth -beg-b urn, the cliffs on either side consist of 

 black and v^'hite soft sandstone in very fine laminae, and much carbonaceous 

 matter is there visible in the underlying shale. At Crachaig Point the sand- 

 stone is of a coarser structure, and, in the sandy shale of the shore beyond 

 that place, I found a large mass of a singular variety of a black carbonate of 

 lime. 



At Kilmot the shelly limestone first noticed at Kintradwell re-appears : here 

 the beds dip in opposite directions and are highly inclined, owing probably 

 to the proximity of the granitic rock. At Kilgour Point the reefs consist of 

 the shelly limestone and grits, and the coast hills increasing in height are 

 composed of shale occasionally seen through a cover of diluvium, and parti- 

 cularly at the mouths of several small streams between this and Portgower. 

 The same order of superposition is apparent throughout the coast from hence 

 to Navidale, wherever the superior strata are not obscured by diluvium ; the 

 shelly limestone and calciferous grit being the lowest rocks, and the shale the 

 highest. Hence, if the former be the equivalent of cornbrash and forest 

 marble, the latter may represent the Oxford clay. 



The finer portions of the shelly agglomerate are burnt for lime at Port- 

 gower, Helmsdale and Navidale. At these places it is a mass of broken shells, 

 agglutinated by an impure calcareous paste, and forming beds from a few 

 inches to two feet in thickness ; besides the terebratulae and aviculae mentioned 

 at Kintradwell, there are found in it univalves, ostrese, and other shells ; with 

 echinital spines, flustrae, &c. These remains are intermixed with abundant 

 minute portions of black lignite, the fossil beds are frequently separated from 

 each other by thin micaceous sandy shales, and the whole are in general based 

 upon bluish calciferous grits. Near the limekilns at Portgower, the disloca- 

 tions are most remarkable ; the dip changing in the space of a few yards from 

 an angle of 25° to one of near 70°, and the line of direction being as sud- 

 denly altered from E. to N. In consequence of the powerful disturbing- forces 

 which have been in action, some of the beds most affected here and along the 

 shore to Kilmot, are made up of portions of shale and sandstone mixed with 

 the shelly limestone, thus forming a conglomerate, of which more will be said 

 hereafter. (See Map, PI. XXXI : Portgower.) 



At a short distance to the N. E. of that place the sandstone and shale, with 

 a bed containing some imperfect fossils, are exposed in the coast hills, and 

 much dismembered by contact with the granitic rock. In the centre of 

 a wild ravine stands a conical hill, at the base of which two mountain torrents 



2r2 



