284 Mr. Weaver on the Structure of the South of Ireland^ 



that we have no transition limestone at all in the south of 

 Ireland *; and by parity of reasoning, that all the schistose 

 and conglomerated rocks associated with these bands of lime- 

 stone in that part of the island, belong to the old red sand- 

 stone formation, since he cannot deny, and indeed admits, 

 that those bands of limestone are interstratified on their con- 

 fines with the adjacent rocks. 



But in another placef , Mr. Griffith observes, " the schis- 

 tose strata of the counties of Waterford, Cork, and Kerry, 

 which form the base of the entire district, consist of grey- 

 wacke and Silurian rocks ;" while in a third place he re- 

 marks:!:, " I am of opinion that eventually the greater part, 

 if not the v/hole, of the schistose rocks of the counties of 

 Kerry and Cork coloured greywacke slate on the map, will 

 prove to be Silurian, with the exception of a narrow stripe of 

 black clayslate which extends from the western base of Cahir- 

 conree mountain to Ballinguard bay east of Dingle harbour." 



This and the preceding quoted passage, when compared 

 with the map of the "Outline," are unintelligible, as the only 

 part of Kerry coloured as greywacke slate is this very band 

 of blackish-grey clayslate, and the only part of Cork so co- 

 loured lies south of the line already noticed, as drawn by Mr. 

 Griffith from the coast opposite Dursey island to the head of 

 Bantry bay and thence toward the southern entrance of Cork 

 harbour^. 



The blackish-grey clayslate to which Mr. Griffith seems to 

 attach so much importance, is only a member of the general 

 transition series, like the greenish-grey, the reddish-brown, 

 and other coloured slates, all which may be readily found in 



* In the new map tins is now accomplished, the limestone being in- 

 cluded and merged in what he is pleased to call "carboniferous slate,'' 

 supported by "yellow and old red sandstone," which assuredly do not 

 exist there. 



t Journal of Geol. Soc.of Dublin, vol. ii. p. 81. % IMd.,i>. 82. 



§ The two passages noticed doubtless have reference to the new map, 

 from the different colouring of which they can alone receive illustration ; 

 and here it is to be observed, that the southern part of Cork coloured in 

 the map of the " Outline '' as greywacke slate, is now in the new map most 

 gratuitously distributed into parallel bands of what Mr. Grifiith is pleased 

 to call "old red sandstone" and " carboniferous slate," to which appella- 

 tions the strata in question have certainly no pretension. Take, as an 

 example, the region of the Audley copper mines in the county of Cork, 

 described by me in §§ 38, 39, of my Memoir on the south of Ireland, which 

 is coloured by Mr. Griffith as old red sandstone. With equal justice might 

 the region of the copper mines in the county of Wicklow be designated as 

 old red sandstone, since in both cases the constituent rocks are clayslate, 

 quartzy clayslate, and quartz-rock. This is one instance, among many, 

 in which hypothetical views are permitted to supersede the dictates of 

 coramon sense. 



