246 RASAY. GEOLOGY. 



therefore we consider them as detached parts of one set 

 of beds, it is evident that these are incurvated in their 

 course ; a circumstance not very unusual, since similar 

 irregularities have been already pointed out in gneiss in 

 various places, and will hereafter be shown to occur 

 among the strata of the Schistose islands. If this be 

 a true representation of the position and connexion of 

 the red sandstone in Rasay, its eastern shore, if suffi- 

 ciently extended, would be surrounded with that rock, 

 as I have already hinted ; * while, if a section adapted to 

 the purpose could any where be discovered, it would be 

 seen to pass under the white sandstone, which would thus 

 be found contained within it on this side as in a basin. 

 It equally follows, that it constitutes the upper part of 

 a great deposit of red sandstone which reaches to the 

 Kyles of Sky and the mainland ; but I shall have occasion 

 to discuss this question at more length hereafter. 



Having thus attempted to ascertain the geological 

 history of this series, I must describe the particular sub- 

 stances which belong to it ; having adopted the former 

 general term, as on other occasions, to facilitate the de- 

 scription, without meaning to confound different mineral 

 substances under one name. 



At the points of contact with the gneiss there is found 

 a very small portion of a conglomerate, which occurs in 

 similar situations in Sutherland, in Ross-shire, and in 

 Morven ; and which might have been enumerated with 

 the varieties of the gneiss, since it is intimately connected 

 with that rock. It is entirely formed of fragments of this 

 substance, broken and reunited with very little change 

 of character ; being of an equal degree of compactness, 

 while, at the same time, it can scarcely be separated 

 from the principal rock. It seems to be as partially 

 distributed as it is small in quantity. In the same situ- 

 ation there is found an equally small quantity of a finer 



* See the Map. 



