352 Proceedings of the Royal Dublin Society. 



The Cambrians of S. E. Wexford show some peculiar phases 

 in metamorphism. Gro northward, along the coast from Carnsore, 

 by Carne to Grreenore, and you meet, first, oligoclasio porphyritic 

 granite ; then oligoclasic coarse gneissic granite, which merges 

 through gneiss into schist, the gradations from the gneissic granite 

 to the gneiss being apparently abrupt ; the section, however, is not 

 very well exposed. If, however, you go a short distance west- 

 ward, you find on the Saltee Island fine orthoclasio gneissic granite, 

 in which are a few subordinate hornblendytes (hornblende- schist) ; 

 while on the main land at Forlorn Point (Kilmore Pier), there are 

 on the south shore-line hornblendytes, which by alternation of beds 

 graduate into a considerable thickness of fine orthoclasic granitic 

 gneiss, the latter to the northward having a hard boundary, out- 

 side of which are hornblendytes and other schists. This sudden 

 change in lithological characters will be hereafter referred to when 

 speaking of the Canadian rocks. 



In the Mourne Mountains district, county Down, there are 

 two distinct granite intrusions (Post-Cambro-Silurian (?) and Post- 

 Carboniferous) (?), the latter, however, possibly Carboniferous. The 

 Cambro-Silurian rocks of the area are altered (sub-metamorphic) 

 by metapepsis, probably an adjunct of the genesis of the older 

 granite; but subsequently, along the boundary of this granite, a 

 newer action was in force, which developed a foliated structure in 

 the adjoining granite, and altered a band of the sub-metamorphic 

 rocks. This, as first pointed out by W. A. Traill, must have 

 taken place subsequent to the intrusion of the granite, as the 

 veins from it into the sub-metamorphic rocks are altered in a 

 similar ratio to what has taken place in them. The rocks now 

 occur in the following order : — 



I The original granite intrusion. 



Granite, 



Gneissic granite, 



Hard boundary. 



Gneiss band, j rm • • i i x i • i 



„ -, . , J ilie origmal sub-metamorphic rocks. 



Schist, ) 



The newer granite (Post- Carboniferous ?) has not to any great 

 extent altered the rocks adjoining it ; but at the same time more 

 or less signs of Paroptesis are apparent. 



