the Primary Rocks and the Oolitic Series in the North of Scotland. 127 



one who may hceafter examine the country. These introductory remarks 

 are, we hope, sufficient to explain the objects we have in view, and the manner 

 in which we purpose to introduce them in the following- communication. 



§ 2. Range of the Old Red Conglomerates through Caithness, and on the 

 Shores of the Murray Firth, ^c. S^c. 



After doubling Cape Wrath from the west, and proceeding nearly three 

 miles along the northern coasts of Scotland, we first meet with the old red 

 conglomerates in Kerwick bay. They are distinctly stratified, and dip towards 

 the north at an angle which is inconsiderable when compared with the high 

 inclination of the primary rocks on which they rest. They stretch along the 

 coast towards Loch Durness, forming a succession of lofty precipices, which, 

 here and there, are worn down into grotesque forms and detached pinnacles 

 by the encroachments of the sea. Towards the interior they are also con- 

 siderably extended, rising into an elevated ridge called Scrisish Ben, from 

 which they descend to the south-west, and pass under the deep morasses of 

 the district. From Loch Durness to the Kyle of Tongue we found no 

 secondary rocks upon the coast; but immediately to the north-east of Lord 

 Reay's house rises a remarkable, pyramidal hill called Craig'-na-Vreckan to 

 the height of about twelve hundred feet, which is entirely composed of the 

 old conglomerate dipping off the coast at a low angle, and, like the deposit 

 last described, resting unconformably upon the micaceous slate rocks of the 

 district. On one side, these conglomerates descend into the cliff; on the other, 

 they are prolonged into the heart of the country, and form several distinct, 

 round-topped hills on the east side of a chain connected with Ben Loyal. 

 Again, on the hills which stretch along the coast from Tongue to Strathy- 

 head, we find no traces of undisturbed secondary rock : but, on approaching 

 Stratliy-water, there are a few loose blocks of conglomerate scattered on the 

 surface ; and thence to Glen Halladale boulders of the same kind are found 

 in great abundance. 



It will appear from the subsequent descriptions of the formations of Caith- 

 ness, that beds of sandstone and bituminous fetid limestone are first seen on 

 the coast to the east of Strathy-water, and that the old conglomerate, forming 

 the base of the whole system, is also seen in the cliff of Port Skerry. Com- 

 bining this fact with the appearance of the boulders before mentioned, there 

 can be no doubt that the old conglomerate is continued into the interior. VVe 

 did not trace the whole of this zone, and therefore cannot assert its unbroken 

 continuity ; but we believe that a region of low conical hills forming an irre- 

 gular south-eastern boundary to tlse morasses of Caithness, is chiedy composed 



