276 Scientific Proceedings, Royal Dublin Society. 



ores are yellow arid grey copper ; but when passing from these into- 

 the Carboniferous Slate, and also in the latter, the ore is principally 

 lead. There are, however, associated with the copper ores, the- 

 ores of various other minerals {see Lists) enumerated in Part I. 



A peculiar lode occurs at Grlandore and at Rosscarbery. It is- 

 associated with a dyke of fault-rock, and has a back of iron ore — 

 in the latter fissures formed, which are nowlfilled with manganese- 

 ore. It has been worked both for the manganese and iron,, 

 but has not been proved in depth. Probably it is a coppery 

 lode. 



"Within the last few years there has been a^movement in favour 

 of the West Cork mines, especially those in' the Sheeps Head pro- 

 montory. Near Kilcrohane, and north-eastward thereof, there 

 have been workings on the large coppery sulphur-ore lodes, and on- 

 some of the bedded grey copper lodes. In these lodes there is a 

 considerable quantity of arsenic ore [arsopyrite) , and in places the 

 carbonate and oxides of copper occur, as profitable " backs " to the 

 lodes. 



There are in some localities large accumulations and veins of 

 barytes, while the copper ores at Dhurode (Carrigagat) and Kil- 

 crohane {Sheeps Head) are auriferous, while the grey copper ore of 

 Lissaremig and Eooska is argentiferous. With the silver-copper 

 there is also silver-lead, while in the old workings at Eooska they 

 raised a considerable quantity of carbonate of iron [Chalybite], 

 which still remains in the attals, or waste heaps. 



Anthracite is stated to have been found at Twomilebridge and 

 Strancally, near Youghal. 



Very good amethysts have been found in places in the Devo- 

 nians, and were formerly utilized. 



Donegal. 



The principal portion of this county is occupied by Granitic 

 and Metamorphic rocks, they having in places on them small 

 patches of Carboniferous Sandstones, Shales, and Limestones. The 

 Metamorphic rocks, in 1884, were discovered by the late Grerrard A. 

 Kinahan to belong to two geological periods, the younger are 

 Ordovicians, and the older must be either Cambrians or Laurentians. 



