SHUNA. GEOLOGY. 153 



the northern and southern extremities. At the latter 

 extremity of the island the direction is north, inclining to 

 the eastward; while at the opposite it is north-easterly 

 inclining to the north; being parallel in both places to 

 those of the strata in the islands with which it is asso- 

 ciated. The point of flexure cannot however be ascer- 

 tained, owing to the intricacy of the ground in the 

 intermediate parts ; or rather, it did not fall under my 

 observation. It is not always possible to investigate 

 these changes in a satisfactory manner, owing to geo- 

 graphical accidents well known to geologists. Yet how- 

 ever desirable it might be to trace these points of 

 curvature, the defect will not interfere with the observa- 

 tions to be deduced from the fact ; the purpose of these 

 being, to bring into one general bearing the detached 

 islands, which, like Garveloch on the one hand and Lunga 

 on the other, affect different directions. Even under 

 these aberrations, a great degree of consistency will be 

 found in the disposition of the rocks throughout all the 

 islands of this division. 



The dip of the strata here, is, like that in the islands 

 already described, towards the east ; and the degree of 

 inclination, though occasionally varying, lies within the 

 limits already described ; namely, between twenty and fifty 

 degrees. 



In composition, Shuna differs materially from the pre- 

 ceding islands, as it presents little or none of the clay 

 slate so prevalent in Luing and Seil, as well as in Scarba 

 and Lunga. The strata are also dissimilar in general 

 appearance and alternation to those of all the islands to 

 the westward ; although essentially but repetitions of 

 rocks which exist in some of these, and still more inti- 

 mately connected with an important series that will be 

 found in a position further to the south, occupying a 

 considerable tract. 



Micaceous schist and quartz rock are the predominant 

 strata, constituting the far larger^portion of the island. 



