34 Rev. A. Sedgwick and Mr. Murchison 07i the Geological 



II. Among these concluding- observations we may remark the great sym- 

 metry of the coast section on both sides of the anticlinal axis. There is hardly 

 a single characteristic group of the descending which may not also be detected 

 in the ascending series. We were assisted in effecting this by the lower beds 

 of mountain limestone^ which cannot be mistaken, and which enabled us to 

 discover, and in imagination to reassemble, the broken fragments of the 

 several formations on the south side of the inferior conglomerates. To this 

 observation there is one remarkable exception. The beds of trap at the south 

 end of Laggan-twine Bay have, we believe, no representatives in any part of 

 the coast section to the south of North Sannox, Does not this, among many 

 other reasons, seem to prove that the trap in question did not originate in the 

 same causes which produced the otiier beds among which it is interposed ? 



III. The same beds of mountain limestone enable us to ascertain the num- 

 ber and the extent of the great faults which interrupt the secondary formations. 

 The marks of dislocation are most visible in the parts of our section where the 

 secondary rocks are spread out at the base of the central mountains of granite ; 

 and the greatest transverse fractures are seen where some bulging protube- 

 rance of granite encroaches on the bearing of the stratified deposits. We 

 believe that no system of subsidences could account for these phaenomena, 

 which appear to us inexplicable on any hypothesis which rejects the mecha- 

 nical elevation of the granitic nucleus. This conclusion is in accordance with 

 what we stated in our introductory remarks on the relations of the slate and 

 granite at Tornigneon near Loch Ranza. 



IV. The preceding conclusion derives a most striking confirmation from the 

 fact, that many of the masses of secondary conglomerate which appear close to 

 the base of the great precipices of granite, do not contain a single pebble of 

 that rock. This fact, which has been frequently remarked before, seems to 

 prove to demonstration, that when the conglomerates were formed, the granite 

 could not have existed, at least at its present elevation *. 



V. If the preceding observations prove that the great dislocations of the 

 secondary strata were produced by the elevation of the granite, it follows that 



* We do not mean to assert that granite pebbles are found in no part of the conglomerates 

 mentioned in the text; the establishment of such a negative proposition would require more ob- 

 servations than are, perhaps, possible : we only assert a general fact, which is sufficient to bear 

 out the conclusion we have drawn from it. During last summer we observed a great many masses 

 of conglomerate, and always found them made up of pebbles derived from the nearest primary 

 mountains. The old conglomerates in the southern parts of Caithness rest, in some instances, on 

 the flanks of granite mountains, and contain so many fragments of the central rock, that it is dif- 

 ficult to determine where the granite ends and the conglomerates begin. Similar facts have been 

 observed at two or three localities near Inverness. 



