96 



Guide to Belfast. 



mass of both the dykes and Silurians is found resting on 

 the intruding granite ; we find in other places that both the 

 granite and the earlier basic dykes are penetrated by another 

 set of basic dykes of a later age. Similar periods of 

 activity are found in the County Antrim, where we find 

 the basalts divided into lower basalts and upper basalts, 

 with an intermediate development of acid rocks. The 

 Antrim series are referred to as of Eocene age, and the 

 Mourne series may be considered as being of the same age. 



THE CASTLES OF KI\'VITAR (.MOURNE .MOUNTAINS). 



Characteristic examples of the weathering of the granite 

 along its joints may be seen in the " castles '' of Com- 

 medagh, which present the appearance of Cyclopean masonry 

 on the face of the cliffs or in the jointed pillars of granite. 

 The texture of the granite varies much, in places being 

 coarsely crystalline, in others being of finer texture. Drusy 

 cavities are frequently met with in which excellent crystals 

 of quartz, felspar, and mica are generally found; less 



