KiLROE — Silurian and Metaniorjohic Rocks. 



151 



as associated with the conglomerate, which may be followed much 

 further east. 



Before passing from this locality it may here be stated that on the 

 original 6-inch maps it has been noted that the " conglomerate 

 containing large, rounded pebbles of quartzite [is] similar to that at 

 Croaghpatrick." The significance of this observation will appear later 

 on. It may also here be stated that in a small area at Knockfadda 

 the beds, some of which are highly calcareous, are transformed into 

 mica-schist ; with this exception, and that of some margining the 

 Corvockbrack granite, the slates and grits of the area have not reached 

 the degree of transformation which justifies other naming than 

 sericite-schists, or phyllites, though in few places have the rocks 

 escaped considerable cleavage. 



Passing eastward to the borders of Lough Mask, the Cregganbaun 

 group is represented by calcareous beds, with a corresponding fauna 

 south of Toormakeady. The fossils may be collected at several points 

 in the Kilbride peninsula, and west of Cong,^ in calcareous strata 

 overlying gray grit mottled with red, and containing annelid bur- 

 rows (pipe-roek), which may be traced southward, across an arm 

 of Lough Mask, through Kilbride and along the top of Bencorragh, 

 south of Lough I^afooey. Here the fossil-bearing greenish calcareous 

 grit is also found overlying the annelid grit, which on being traced still 

 westward passes into purple grit and red slate. There is, therefore, 

 little doubt that here we have still represented the Cregganbaun 

 group, but under circumstances entirely different from those at this 

 latter point, as I now proceed to show. 



It will be noticed on the 1-inch published maps, which are 

 summarized upon the one accompanying this paper, that the pipe-rock 

 and overlying fossil-bearing calcareous beds dip eastward and south- 

 ward from conglomerates, grits, andfelsites of (?) Bala Age. Indeed, 

 the felsites at Toormakeady follow directly upon black slate, in 

 which I collected graptolites of Lower Llandeilo or Arenig Age, 

 about a mile north of the hamlet so that volcanic activity may have 

 commenced earlier than Bala times in this district, though doubtless 

 continued while limestones of this age were being formed. =^ This view 



^ Explanatory Memoirs of Sheets 85 and 95, p. 15. 



- Ancient Volcanoes of Great Britain, by Sir A. Geikie, d.c.l., ll.d., f.r.s., 

 vol. i., p. 49. 



^ In the Toormakeady complex I noticed some felsites and ash-like igneous 

 breccias which, as intrusions into rocks adjoining them probably carried the 



