40 Mr. Weaver on the Geological Relations of the South of Ireland. 



(55.) The association of the limestone with black carbonaceous shale, may 

 be observed to advantage both in the west and east of the field. 



Tn the west, these rocks appear on the coast to the north of the Cashen or 

 Feale river, extending nearly two miles between Ballybunnian and Lick Castle, 

 alternating both in thin and very thick beds, whose general inclination is to- 

 ward the north-east, yet undulated on the large scale, commonly under an 

 angle of 25° to 30°, but in some places they are at high angles, and even ver- 

 tical. These great undulations have been broken in upon, by inroads of the 

 sea in a direction from west to east, forming six or seven inlets or coves, in 

 which, by abruption and perforation, the rocks have been wrought into a variety 

 of fantastic forms, with archways and caverns winding into the interior. In 

 the black shale, iron pyrites being incidentally disseminated, and mutual de- 

 composition taking place, alum, hydrate of iron, &c. are produced, and the face 

 of the rock becomes stained with white, yellow, brown, and reddish depositions. 

 These substances penetrate also into the fissures of the rock, in which wavellite 

 likewise is found. 



In the east we may notice that portion of the carboniferous limestone which 

 is adjacent to the angular boundary, formed by the conjunction of the counties 

 of Cork, Limerick, and Tipperary. It there contains massy beds, both of 

 grey slate-clay and black carbonaceous shale, in the latter of which iron py- 

 rites is not unfrequently distributed. The appearance of this black shale gave 

 rise to trials for coal about forty years since, several pits having been sunk for 

 that purpose, but without any success. 



(56.) The association of the carboniferous limestone with trap and porphyry, 

 has been treated by me, at some length, in my Memoir on the East of Ireland *, 

 and I therein indicated (§. 178.) that the distribution of those rocks in the lime- 

 stone, was probably more extensive than I had then an opportunity of ascer- 

 taining. The subject has since been resumed, both by Dr. Apjohnf and 

 Mr. Ainsworth];, and to the respective memoirs of those gentlemen I beg to 

 refer for the details of their extended researches. With Caj)tain Sabine, R.A., 

 and Mr. Ainsworth, I have since had the satisfaction of visiting part of the 

 ground formerly left by me unexplored ; and in the map I have introduced the 

 range of the trappean and porphyritic series determined by the latter. Of 

 that portion of the district which hes to the west and north-west of the field for- 

 merly examined by me, a general view may be obtained from the hill of Car- 

 rig Parsons, situated about midway between Limerick and Pallis Hill, over- 

 looking the vale which extends to the foot of the Bilboa mountains on the north. 



* Geol. Trans., First Series, Vol. 5. 



•\ Journal of the Geological Society of Dublin, No. 1. X Ibid., No. 2. 



