1858.] 



HARKNESS JOINTINGS . 



91 



and in the old quarry at Glasheen, about a mile west from Cork. 

 The whole series is also represented on the north face of this quarry 

 (fig. 5) ; and here we have the inclined joints on the west side dipping 

 west, and on the east side, east at nearly the. same angle. The 

 features of jointing, as exhibited at this quarry, are shown in fig 5. 

 There are instances where oblique joints have not the usual east 

 and west inclination, and where they are not accompanied by hori- 

 zontal joints, or at least only very partially so. An instance of this 

 kind occurs in the north end of the principal cutting of the Cork and 

 Passage Railway (fig. 6), where N. and S. joints are seen devoid of 



Eig. 6. — Joints {two courses) in the Carboniferous Limestone at the 

 north end of the cutting in the CorTc and Passage Railway. 



those of a secondary character, adjoining other N. and S. joints in- 

 tersected by oblique joints dipping N. W. at an angle of 60°. 



In most of the quarries and cuttings around Cork, the limestones 

 offer few traces of the original bedding ; and in many places the 

 stratification of these rocks is absolutely obliterated. To such an 

 extent does this occur, that in many quarries there is not the slightest 

 evidence of bedding to be found ; and so regular are the north and 

 south vertical joints, which cut up the limestone into strata-like 

 masses, that, were it not for the information afforded by the general 

 geology of the country as to the strike of the limestone-strata, these 

 rocks would be regarded as having vertical strata striking north and 

 south, — a conclusion as far as possible at variance with the true 

 direction. As in many limestones of the Alpine countries and other 

 districts which have been subjected to the operation of powerful 

 forces, stratification has in most instances been here destroyed, and 

 jointings appear to have usurped its place. 



Although, for the most part, the Carboniferous limestones of the 

 district around Cork exhibit these several forms of jointing in a very 



