364 ARRAN. GEOLOGY. SCHIST. 



that it contains all the substances described as found 

 in it in Arran. With the same general characters, it 

 extends through the whole- space which it occupies; 

 differing only by the occasional exclusion of some of 

 the substances, or by the varying proportions of the 

 whole. Throughout its course it also follows the 

 micaceous schist, wherever that exists ; passing into this 

 series by the same uncertainty of gradation or alternation. 

 It is also followed in immediate superposition by the 

 red sandstone; the strata of that rock being either 

 conformable to it or otherwise, according to the varia- 

 tions of circumstances which it is here unnecessary to 

 consider. The line occupied by this series conforms 

 exactly to the prevailing direction of the strata of the 

 country, namely north-east; and it is thus extended 

 in one belt from the easternmost point of Scotland where 

 it is visible, to Bute ; being subjected to no other deviation 

 or irregularity than those slight undulations already often 

 noticed, from which none of the Scottish strata seem 

 exempt. The dip of this series, like that of the micaceous 

 schist which it follows, may, under the same exceptions, 

 be considered as regular, being towards the south-west. 



But in examining the strata, both of the argillaceous 

 and of the micaceous series, as they occur in Arran, 

 their contact is found to be interrupted for a certain 

 space by a mass of granite. At the same time, the 

 regularity of the separated portions is destroyed ; the 

 parts of each no longer preserving th.e usual parallel 

 position among themselves, nor the same common linear 

 direction : the common dip, as well as the common 

 direction of each separate series, is in short annihilated. 

 It has already been remarked that such is here the 

 confusion, that these dips cannot be exactly ascertained ; 

 yet it is evident on comparing a great number of the 

 several parts, that the predominant tendency of the 

 whole is that of a conformity to the surface of the granite 

 on all sides; or, in other words, that the strata repose 



