KiNAHAN — On Some of the Irish Crystalline Iron Ores. 315 



as the ore at Kiloolman, It dips under the coal-measures, and 

 when first opened it contained a thick deposit of slightly ferriferous 

 cave earth. A chalybeate stream occupies it during part of the 

 year ; but as the water does not deposit any iron in the cave, the 

 iron must be accumulating in some subterranean cavity, or the 

 water must come to the surface a good distance away in a chaly- 

 beate spring. 



Counties of Cork and Waterford, 



These counties were once famous for their iron mines; but 

 although it is easy to find the sites of the forges and iron mills, the 

 old workings are unknown, or cannot be examined in their present 

 state. These mines seem to have been principally situated in the 

 Yellow Sandstone ground, but some were in the Old Red Sand- 

 stone, and others in the Carboniferous Slate. 



Some of the iron ores appeared to occur as the gossan back of 

 copper lodes, but others have all the appearance of being indepen- 

 dent lodes. At Grlandore, county of Cork, there is a limonite back 

 to a copper lode. This lode is remarkable, as the present " mineral 

 channel " was first a brecciated " fault-rock," in which fissures 

 opened that were filled by the copper lode ; while, after the iron ore 

 back had formed, a second system of fissure opened in the iron ore 

 and the associated breccia, which are now occupied by manganese 

 ores. 



At the west end of Bear Island there is a standing lode of 

 hematite, about eight feet wide, in the Carboniferous Slate ; while 

 elsewhere there are many smaller and usually irregular veins and 

 strings of hematite, ofter the micaceous variety. These veins seem 

 to be best developed in the areas where there are Intrusive Eocks. 



As these veins occur below the black shales of the Carboniferous 

 Slate group, it is possible that the ore may have had its genesis from 

 the pyrites [in them, or it may have welled up from below, it 

 being in part the leaching of the underlying purple and red rocks 

 of the Upper and Lower Old Eed Sandstone. 



It should be pointed out that there was a centre of vulcanicity 

 in the neighbourhood of Berehaven during the accumulation of the 

 Carboniferous Rocks, which probably had some kind of connexion 

 with the development of the iron ore strings and veins. This action 

 also seems to have had something to do with the accumulation of 



