312 Geological Society. 



at Grcenoro, and on the S.AV. coast of AVcxford. At the former it is 

 a fine reddish conglomerate, lying on or against schists; at the 

 latter a massive slate conglomerate. The rocks of this series in 

 ascending order are: — 1, Black carbonaceous shales and slates, or 

 grey beds with subordinate beds of grit ; 2. Green and grey grits, 

 shales, and slates; 3. The Ballymoney series of green, grey, black, 

 and red grits, sandstones, slates, and shales, -svith interstratified 

 igneous rocks ; 4. Red, purple, and green beds, usually more or less 

 argillaceous. 



The Cambrian formation generally consists of green, purple, or 

 reddish grits, shales, and slates, but here and there with grey or 

 even black beds. The author describes the Cambrian rocks in the 

 various areas in which they occur, namely at : — 



Howth, where they are but little altered in the N., becoming more 

 altered towards the S. 



Bray Head, generally unaltered, and containing many specimens 

 of Oldliamia, and with massive dykes of quartz rock. 



S.E. AYicklow, where the western boundary is doubtful. Near 

 Carrick Mountain and to the westward the rocks are much altered, 

 and the author thinks that probably masses of Cambrian rocks were 

 forced by disturbances into the Cambro-Silurians, and then the 

 whole were metamorphosed together. 



N.E. Wexford. The area commences on the east coast near Cour- 

 town Harbour, extends S. to and beyond Wexford, and then S.W. to 

 the coast near Bannow Bay. The rocks are generally submeta- 

 moiphic, with many large protrusions of quartz rock, generally 

 changed by metapepsis into quartzite. Eooney's Eocks, S. of 

 Poulshore, consist of two protrusions of quartz rock, between and 

 N. of which are green and purplish Cambrian shales, in which 

 Oldliamia antiqua has been found, as also in a green bed further 

 south at Cahore. On the coast of Haggard and Bannow the Cam- 

 brian and Cambro-Silurian rocks are mixed up very irregularly by 

 means of numerous faults. At Bannow Oldliamia is not uncommon. 

 The most continuous sections are seen in this area in the valley 

 of the river Slaney, where the rocks generally dip to the N. at 

 angles of 10°-60° or 80°, and are, going from K. to S. :— 



1. Massive grits with some shaly beds, underlain by 



more or less altered grits and shales ; average dip 



30°, giving a thickness of about 3000 feet. 



2. Schists with quartzites (metamorphosed grits), d' p 



50°; about 4000 „ 



3. Schists with masses of quartzite (altered quartz 



rock), dip 40°; about 4000 „ 



Total about 11000 „ 



but the numerous faults render the numbers uncertain. 



S.E. Wexford. The rocks are more or less metamorphosed, gra- 

 duating from schist through gneiss into granite near Carnsore. 



