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



diately to the east of the deepest of these indentations, there is a projecting- 

 portion of the clitF, which, when seen from a distance, appears of a deep red 

 colour. A mass of granite, in rude prismatic forms, here intrudes upon the 

 stratified rocks, and occupies the coast for three or four hundred feet. On the 

 western side of this junction the beds are in the utmost confusion, the limestone 

 being- not only highly inclined, but also crystalline and cellular. Close to the 

 point of contact these same beds assume a brecciated structure, and even 

 contain many fragments of the granite itself*. 



The contiguous portions of the cliff are chiefly composed of this breccia, 

 through which the red granite protrudes with much irregularity. Some masses 

 of the conglomerate rest upon the tilted edges of the limestone, whilst others 

 are of a wedge shape, and appear as if they had been mechanically driven in 

 among the shattered edges of the higher beds of limestone and sandstone. 

 The cement of the conglomerate is generally granitic ; it is, however, in some 

 parts calcareous, and in other places it approaches to the character of sand- 

 stone : — one great block of sandstone, with the usual undulating surface, 

 seemed to be entangled in the granite. At the eastern extremity of this dis- 

 turbed portion of the cliff there is no conglomerate, and the stratified beds 

 cannot be traced into immediate contact witli tlie intruding granite; neither 

 do their dip and direction appear to have been much disturbed*. 



This mass of well-characterized granite may be considered as the extreme 

 spur of a ridge of that rock, which, in retiring from the coast, is first seen in 

 rounded knolls on the north of Sandside House, whence it ranges to the south- 

 east, and rises into a low chain called the Dornery Hills, which are peninsu- 

 lated amidst the plains of calcareous schist and sandstone of Caithness. The 

 peculiar effects described as having been produced by its contact with the 

 secondary strata on the coast, cannot be observed in the interior, owing- to 

 the thick covering of alluvial matter and morass which are so extensively 

 spread over the surface of these vast plains f. 



The cliffs of sandstone and schist subside to the east of Sandside Bay ; and the strata, for a 

 considerable distance, are only seen in ledges on a shelving shore, and occasionally much con- 

 cealed by blown sand ; but they again rise gradually into a low projecting headland called 

 Broomnefs(Briinness). The same lamellar limestone mentioned, as occurring at Strathy Bighouse, 

 kc. is quarried here and there on the coast : whilst, in the interior, calcareous schists occupy the 



* See Plate XIV. fig. 1. 



t It appeared to us on the spot, that the disturbed and brecciated masses described in the text 

 could not be brought into comparison with the old conglomerates of Port Siierry. They seemed 

 rather to resemble in their origin the breccia on the south side of the Ord (see Geol. Trans. 

 Second Series, vol. ii. Part II. p. 306.), and to have been formed by the mechanical action of the 

 granite, which must, in that case, have been protruded in this place, after the deposition of the 

 part of the secondary system above described. 



