1857.] GEIKIE SKYE. 19 



remarkable example of weathering is probably that on the beach 

 south of Camus Smalaig, where, to the action of the atmosphere, 

 there has been added that of the waves. The rock is there of a 

 leadeii-blue colour, and its surface bristles thickly with sharp rough 

 irregular fragments, having a greenish hue and adhering to the 

 marble often by the merest point. These small roughnesses are so 

 angular as to wound the hand when it is passed even gently across 

 them, and they render walking dangerous alike to boots and skin. 

 I can compare them to nothing but what we might conceive would 

 be the appearance presented by a shower of moist tea-leaves that 

 had been thrown athwart a freezing pond and become hard and 

 fixed in the ice. 



The texture and colour of the marble vary in different parts of 

 the district. The whitest varieties are to be seen at the Kilchrist 

 quarries, and in the vicinity of Kilbride. In each of these localities 

 there is a large mass of syenite close at hand. Various shades of 

 grey occur, in some instances (as on the shore south of Camus Sma- 

 laig), in contact with the syenite, — the marble assuming a crystalline 

 or saccharoid texture. Green streaks of serpentine mottle the rock 

 where it is intersected by trap-dykes, and also, at Camus Smalaig, 

 where it is cut through by syenite. Specimens may also be obtained 

 prettily veined with blue and purple (rarely with red) even in the 

 immediate vicinity of the purest crystalline varieties, as at the Kil- 

 christ quarries. As the marble recedes from the syenite it darkens 

 in colour, loses its metamorphic aspect, and gradually passes into an 

 ordinary limestone. 



On the exposed marble-cliffs that fringe Loch Slapin, a little way 

 north of Glen Kilbride, I have found what appears to be the frag- 

 ment of a Pentacrinite. With this exception I have not succeeded 

 in detecting in the altered limestone any trace of organic remains. 

 There are, however, a number of rough nodular accretions of cherty 

 carbonate of lime, of great hardness, that protrude, sometimes in 

 considerable numbers, from the smooth surface of the marble. These 

 may represent some of the organisms seen along the eastern shores, 

 and I have sometimes fancied that my eye could detect what bore a 

 remote resemblance to a Gryphite. If such irregular nodules do 

 actually represent Ammonites, Gryphcece, &c, these organisms must 

 have undergone no little distortion and obliteration — Pentacrinite, 

 Ammonite, and Pecten being jumbled together into rugged lumps of 

 cherty limestone. 



The passage of the metamorphic into the unaltered limestone is 

 a point of considerable interest, and may be studied to advantage on 

 the shore of Loch Slapin at the mouth of Glen Kilbride (MS. Sketch 

 No. 13). There the altered limestone is seen abutting against the 

 syenite of Beinn an Dubhaich. As it approaches the sea it becomes 

 dark, compact, and dull in grain, with streaks of white, but devoid 

 of fossils. Then occur seams of lighter-coloured limestone and hard 

 shale with Gryphcece, succeeded by a dark blue close-grained lime- 

 stone with Ammonites, &c. These beds are followed southwards by 

 calcareous grits, sandstones, and limestones similar to those above 



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