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



which flows into Cork harbour, Mr. Nimmo informed me that Orthoceratites 

 and other organic remains are also to be met with in the slate ; and Mr. S. 

 Wright, of Cork, assures me that he has frequently seen small Orthoceratites 

 in the clay-slate near the town of Cove in Cork harbour; also Spiriferae or 

 Terebratulae in the slate on the Bandon road, five miles south from Cork, but 

 not sufficiently distinct to admit of the identification of species. 



(14.) In tracing the transition rocks from Kerry into the counties of Cork 

 and Waterford, an analogous structure and composition are everywhere per- 

 ceptible, diversified, however, by numerous varieties ; one member also some- 

 times prevailing more than another in the series. Of this disposition the 

 unequal bands of limestone which pervade the tract, as well as the isolated 

 patches more locally distributed, are sufficient exemplifications. The general 

 observation may also be made, that the conglomerated structure, and the reddish 

 or brownish hue are more particularly developed in the greywacke and slate 

 rocks which occur north of the parallel of the river Lee ; while in the parallel 

 to the south of that river the same class of rocks exhibits commonly a finer 

 structure and a light bluish or greenish grey cast ; but both parallels contain 

 incidentally the other modifications which have been noticed. 



(15.) The transition rocks on the south coast of the county of Waterford 

 extend from the vicinity of Dungarvan toward Tramore. As they exhibit a 

 series of considerable interest, I shall here subjoin such an account of them 

 as may help to complete our view of the modified structure and association of 

 the general series. 



Clay-slate. — 1. More or less pure, and partly glossy; blackish, bluish, greenish, or yellowish 

 grey ; also reddish brown or purplish. These slates contain more or less numerous scales of sil- 

 very mica disposed parallel to the laminas. The blackish slates are partly aluminous. 2. Quartzy 

 clay-slate containing some crystals of felspar. 3. Quartzy clay-slate containing finely disseminated 

 hornblende, and sometimes also crystals of glassy felspar. 4, Clay-slate very firm, yet fissile, 

 partly porphyritic. 



Greywacke.— I. Slate enveloping crowded grains of quartz as large as peas, portions of the 

 paste consisting also of green steatite. 2. Slate or quartzy slate inclosing angular and rounded 

 grains of quartz, with small fragments of slate, and numerous scales of silvery mica, and with or 

 without grains of felspar. 3. Greywacke slate, the same rock as the preceding, but of fine grain 

 and slaty structure. 4. A fine-grained base, compounded of slate and quartz, containing isolated, 

 round grains of white quartz, of the size of large peas, the rock at a distance appearing like an 

 amygdaloid. 



Quartz-rock.— I. In its simple forms. 2. Containing small globules of chlorite, and also particles 

 of hornblende, from the partial decomposition of which it acquires an ochreous aspect. 3. Quartz- 

 rock (sometimes graduating into hornstone, or partially into compact felspar), containing numer- 

 ous reddish and yellowish white crystals of felspar, forming a handsome porphyry ; sometimes 

 containing also particles of hornblende. 4. Quartz-rock (sometimes merging into hornstone). 



