RUM. GEOLOGY. 481 



or of the lias beds which, as will shortly be seen, occur 

 in the neighbouring island of Egg. Nor is there in 

 Rum any indication of the gneiss or of the chlorite 

 schist which in Sky precedes the sandstone ; this rock 

 being the only regular stratified substance in the island. 

 The proof of the identity of these strata in the two 

 islands must therefore rest on the community of position 

 and of structure which characterize them in both. 



The beds of schist* appertaining to this series are 

 in general situated veiy low on the shores where they 

 occur, and may be seen in different places, lying immediately 

 below the red sandstone. They consist of an irregular 

 alternating series of dark blue clay slate with blue 

 quartz rock, precisely similar to those of Loch Eishort in 

 Sky; like them conformable to the sandstone above, 

 and occasionally alternating with it. They are first 

 visible at Cove, and in proceeding to the south, they 

 continue to rise till they form cliffs of considerable alti- 

 tude; when, their inclination gradually changing, they 

 become at length horizontal. The cliffs vary in height, 

 and beyond Glen Debbie attain an elevation of about 

 100 feet. In general these strata are very even and 

 regular, although they are in many places traversed by 

 trap veins ; but in some instances they seem to be 

 disturbed. Beyond Glen Debbie, at a nameless point, 

 they change their inclination, and thus, subsiding below 

 the sea, are lost to the sight. It is here unnecessary 

 to make any further remarks, either on this series of 

 rocks, or on the connexion of these strata with the super- 

 incumbent sandstone; as these points have been suffi- 

 ciently examined in describing the preceding islands. The 

 circumstances already mentioned are sufficient to prove 

 their identity with those formerly reviewed. 



It is equally unnecessary to enter into details re- 

 specting the nature of the red sandstone, since it has also 



Plate XIX. tig. S. 

 VOL. I. 11 



