508 GAKVH ISLAND. GEOLOGY. 



GARVH ISLAND. (DIURNESS.) 



ALTHOUGH this small spot is unconnected with any 

 of the groups into which the preceding isles were asso- 

 ciated, and does not perhaps, in strictness, rank among 

 the Western islands, I am induced to notice it on account 

 of the peculiarity of the calcareous tract to which it 

 belongs. Its geological interest will be found consider- 

 able, though its dimensions are insignificant ; but as that 

 interest is chiefly derived from a contemplation of the 

 whole tract, it will be necessary to give a sketch of this as 

 it occupies the inlets of Diurness and of Loch Eribol. 



Garvh island lies off the entrance of Diurness bay, being 

 of an irregular oval shape, not exceeding half a mile in its 

 largest dimensions, and forming a table land surrounded 

 on all sides by cliffs of about forty or fifty feet in elevation. 

 It is about a mile from the nearest shore, and is not 

 inhabited. 



That shore consists of the red sandstone formerly 

 described, but this island is an entire mass of limestone, 

 corresponding with a tract of similar rock which lies, at the 

 distance of less than two miles, on the west side of Diur- 

 ness bay. This small tract consists of three rocky islets, 

 called Eilan na gurach, and of a low ridge skirting the 

 shore for about a mile and a half. The relative position 

 and general correspondence of all these detached parts, 

 indicate that they were once connected ; and it will imme- 

 diately be shown that they are related to a more extensive 

 range of calcareous strata which occupy the east side of 

 this bay. 



The limestone of Garvh island, like that of the neigh- 

 bouring tracts, is disposed in strata having a north-easterly 



* Garrow in Arrow smith's map. It could not be included in the 

 map that accompanies this work. 



