1873.] HULL — PERMIAN OF AEMAGH. 405 



amount of strata which cannot be estimated, at less than 5000 feet 

 in thickness. 



This leads me to observe that the Carboniferous rocks of the north- 

 east of Ireland appear to have been subjected to the same system of 

 flexures, accompanied by denudation, which on a former occasion I 

 have shown to have taken place in the case of the same beds in 

 Lancashire at the close of the Carboniferous Period*. The lines 

 of flexure of the Carboniferous rocks of Monaghan, Armagh, and 

 Tyrone t are, in fact, parallel to " the Pendle Axis" of North Lan- 

 cashire, which ranges in an E.N.E. and W.S.W. direction; and in 

 both cases we find Lower Permian beds resting directly upon those 

 of Lower Carboniferous age, showing a complete parallelism of 

 physical relations. It is, therefore, clear that at the close of the 

 Carboniferous Period the rocks were subjected to an enormous 

 amount of denudation, consequent on the terrestrial movements which 

 ensued, as well in the north of Ireland as in England — an inference 

 which is borne out by the relative positions of the Permian tracts of 

 Cultra and Artrea. 



Permian Beds of Benhurb. — There is another hitherto unnoticed 

 patch of Lower Permian beds, shown in the banks of the river 

 Blackwater above Benburb, between Armagh and Dungannon. The 

 section is exceedingly obscure, and is to be made out chiefly in the 

 canal-cutting which lies parallel with the river. The beds consist 

 of alternating red marls, purple sandstones, calcareous breccias, and 

 one or two beds of brecciated limestone two or three feet in thick- 

 ness. The whole of these rest on the upper member of the Carboni- 

 ferous Limestone, and therefore in a position about 2000 feet higher 

 than in the case of the Armagh boulder-beds. Mr. Baily, E.G.S., 

 has examined a few obscure fossils from the limestone, which he re- 

 gards as Carboniferous species ; but they seem to be not sufficiently 

 perfect for identification ; and as I consider the limestone itself to be 

 derivative, and simply a reconstruction of Carboniferous materials, I 

 attach little value to the species of the fossils, even if they were 

 capable of definite identification. 



If the Benburb beds had been solitary examples in this district of 

 strata of apparently Permian age, I should have had some hesitation 

 in referring them to that formation ; but as they are situated only a 

 few miles distant from the undoubtedly Permian beds of Armagh, I 

 have confidence in the correctness of the identification. 



Discussion. 



Mr. Peestwich inquired whether in the Permian beds there were 

 no limestone pebbles, such as in all probability would have been 

 striated had they been of glacial origin. 



* " On the Eelative Ages of the Leading Physical Features and Lines of 

 Elevation of the Carboniferous District of Lancashire and Yorkshire," Quart. 

 Journ. Geol. Soc. vol. xxiv. p. 323. 



t The base of the Carboniferous Limestone passing by Clones, Monaghan, and 

 Armagh reappears on the southern shores of Belfast Lough at Cultra, near 

 Holywood, on the same line of upheaval. 



