632 J. NOLAN ON THE OID EED SANDSTONE 



bonif erons Sandstone " tract west of Draperstown, Co. Derry ; these 

 are succeeded by purple fine-grained and sometimes cleaved sand- 

 stones, the highest beds being greenish-grey and olive-coloured grits, 

 which are classed as the upper part of the Old Eed Sandstone 

 (Kiltorcan beds), but for which I do not know any representatives 

 in the North of Ireland. Lastly, these are followed by a thin band 

 of Limestone shale and Lower Limestone, forming the massive 

 crags on which the castle of Lismore is romantically situated. 



Similar observations were made at the Galtees, and the western 

 prolongation of that range called the Ballyhoura mountains. In a 

 section at the latter, some four miles north of Buttevant, Co. Cork, 

 the highest beds seen were reddish to light purple fine-grained sand- 

 stones and clay rocks, alternating with yellowish grit and shale, 

 which are regarded as the upper part of the Old Eed Sandstone ; 

 while the lower division consists of micaceous purple sandstones 

 and shales over coarse yellowish -white and reddish-brown pebbly 

 sandstones and quartzose conglomerates, of the same kind, though 

 not so massive, as those in the basal beds of the formation at "Water- 

 ford. On the flanks of the Galtees near Kilbeheny similar facts 

 were observed, reddish-brown to purple sandstones and sandy shales 

 alternating with quartzose pebble-beds and conglomerates. 



On the whole, therefore, I found the closest resemblance in litho- 

 logical character between these typical Old Eed Sandstones of the 

 south of Ireland and those which in the north and other parts of 

 Ireland have been called Carboniferous — a point which is well 

 worthy of observation, as formations perfectly identical thus come 

 to be placed on diff'erent geological horizons. Unfortunately no 

 fossils have been found which would serve for comparison, except in 

 the Upper Old Eed Sandstone, where the remarkable freshwater 

 fauna and plant-remains of Kiltorcan occur, which have been so well 

 described by Mr. Baily. This formation, however, is, as before 

 remarked, not known in the North of Ireland. 



Turning now to the sandstone district which it is particularly in- 

 tended to describe in this paper, we find in Tyrone, that the upper 

 or quartzose conglomerates (so-called Carboniferous sandstones) are 

 succeeded by the Carboniferous Limestone ; but as they are traced 

 further north into County Derry, a considerable thickness of sand- 

 stone and other beds come in between them and the limestone. 

 These intermediate rocks attain a great development at Dungiven 

 and about Draperstown. At the stream called the White Water, 

 in the latter locality, an excellent section is exposed. The under- 

 lying or '^ Lower Carboniferous" series consists of the usual 

 quartzose conglomerates, coarse purple sandstones, and sandy 

 shales, also a remarkable rock mostly composed of reddish-brown 

 and purple grit pebbles, apparently derived from the Pintona series, 

 closely resembling some of the basal beds that overlie the latter 

 in the district south of Pomeroy, Co. Tyrone. Over these is the 

 series of sandstones referred to ; the lowest beds are yellowish-grey 

 ^nd massive grits with pebbles, red to purplish sandstones, thin 



