Geological Society. 149 



paria, bivalves, Trilobites, &c. occur near the Bonmahon river ; the 

 horizontal planes which they occupy crossing the vertical cleavage of 

 the slaty grauwacke nearly at right angles. The series rests upon, 

 and passes into clay-slate, and is capped by old red sandstone and 

 strata of the carboniferous order. Metalliferous veins with indications 

 of copper and lead are seen in the cliffs of the transition series, east 

 and west of the Bonmahon river. 



II. Metalliferous relations in Kerry and Cork. 



The author having succeeded in restoring the copper mines at 

 Ross Island, on the Lake of Killarney, and in effectually draining off 

 the water, was enabled to prove that the ore did not constitute a me- 

 talliferous bed, or any real vein, but was contemporaneous with 

 the rock in which it is irregularly distributed in the form of ribs, 

 branches, strings, &c., analogous to those of calcareous spar, in 

 limestone. The rocks at Ross Island consist of blue limestone, and 

 beneath it of siliceous limestone, but the ore is confined exclusively 

 to the former ; and various trials have proved the non-existence of 

 any vein communicating with the metalliferous deposit. Copper ore 

 is similarly distributed at Crow Island : — but at the Muckruss mines 

 the ore was obtained chiefly from a metalliferous bed. The author 

 has ascertained exactly the extent of the limestone bearing lead in 

 Kenmare, where most of the unsuccessful trials in search of ore have 

 shown that the mineral deposits are discontinuous, and nearly parallel 

 to the range and dip of the beds ; and in Castlemaine mine, where 

 lead ore was formerly worked in a mass of calcareous spar and 

 quartz, it thinned out into an unproductive pipe. Near Tralee and 

 Ardfort, and on the left bank of the Shannon, lead ore has been un- 

 profitably worked in limestone, sandstone and slate. 



In the county of Cork, the copper mines are those of Allihies, 

 Audley, and Ballydehol ; and those producing lead are situated at 

 Doneen and Rinabelly. The mine at Allihies is one of the richest 

 mines in Ireland ; it was discovered only in 1812, and has already 

 yielded more than 2000 tons of copper ore per annum. The ore occurs 

 in a large quartz- vein, which generally intersects the slaty rocks of the, 

 country from north to south, but in some places runs parallel to the 

 stratification. It is remarked that all this portion of the county of 

 Cork indicates a very general diffusion of cupreous particles, so much 

 so, that in the year 1812 there existed a cupriferous peat-bog on the 

 east side of Glandore harbour, forty or fifty tons of the dried peat 

 producing when burnt, one ton of ashes, containing from ten to fifteen 

 per cent of copper. The lead mines of Doneen and Rinabelly are in 

 slate. 



In concluding a long series of observations on the mines of the 

 tracts described in this paper, the author remarks that the diffusion 

 of metallic substances throughout the mass of rocks is far from being 

 an uncommon occurrence — the metalliferous matter appearing in 

 isolated particles, and in strings, veins or filaments, more or less con- 

 nected with each other, but not continuous or persistent, and there- 

 fore of contemporaneous origin with the rock itself. 



III. Car- 



