Mr. Weaver on the Geological Relations of the South of Ireland. 9 



the series progressively rising at a higher angle until they become vertical, 

 while still further south a successive interchange of dip takes place in these 

 beds, analogous to that already noticed as occurring throughout the transi- 

 tion field. To the eastward, this series is overlaid by the old red sandstone 

 of Slieve Meesh, which forms a flatly arched inflection from north to south; 

 but at its eastern foot the grey wacke re-appears adjacent to the river Maine. 



In various parts of the country, the basis of the fine-grained grey wacke is found occasionally to 

 effervesce partially witli acids, though no calcareous matter be obvious to the eye. Such, however, 

 does casually appear when approaching the limestone, and sometimes even at the distance of one 

 or more miles. 



In the quartz conglomerate, the basis being quartz, the ingredients are analogous to those of the 

 clay- slate conglomerate. In the sandstone conglomerate also the larger included portions are essen- 

 tially composed of quartz and slate, the former being usually white or grey, but sometimes tinged 

 reddish or greenish ; while the basis consists of compact, granular or sandy quartz, numerous 

 scales of silvery mica, and an occasional diffusion of white earth, like that which proceeds 

 from decomposed felspar. From this coarse compound, a gradual transition may be traced to the 

 finer-grained sandstone and sandstone of a slaty structure, and thence, by the greater consolidation 

 of quartzose matter, into quartz-rock itself. 



This gradation may be seen exemplified in the entrance of Dunloe Pass, 

 where all these rocks possess more or less a reddish or brownish tint, agree- 

 ing in that respect with the neighbouring clay-slate. Those which are first 

 encountered dip at an angle of 60" to the S., which angle they retain until we 

 find a bed of the sandstone conglomerate in juxta-position with a reddish 

 roofing-slate, the latter dipping 63° S. at the point of contact, but at a di- 

 stance from the conglomerate (being about 70 yards thick) gradually assuming 

 the vertical position. Further S. the beds decline to as low angles as 35° 

 and 30°, — then undulate on a small scale for some distance, and subsequently 

 resume the southerly dip at a higher angle. But from Dunloe Pass to 

 Kenmare Bay, though the more general disposition of the strata be to the S., 

 an occasional change of dip toward the N. is also observable, vertical strata in 

 such cases commonly intervening. 



(11.) I may here remark that in the whole extent of the grey wacke and slate 

 country, contemporaneous veins of quartz are more or less common to the seve- 

 ral members of that series, most usually traversing them in the line of the dip, 



(IS.) It will be seen in the Map, that the distribution of the limestone is 

 very unequal in the general expanse of the transition field, the interposed 

 masses not assuming a regular form ; yet the strata are always parallel to those 

 of the rocks with which the limestone is in contact ; and within the limestone 

 ranges, the stratification is occasionally subject to inflections and variations in 

 the line of dip, as well as to contortions, analogous to those within the grey- 



VOL. V. SECOND SERIES. C 



