210 E. T. Hardman — Raised Beach at Tramore. 



original outline of the centres of eruption have been more or less 

 preserved. With us, however, it is different, and it is plain that 

 the nortli of Ii-eland and the western isles of Scotland have been 

 subjected to agents of abrasion from which the other districts I have 

 referred to have been to a great extent free. 



It is to the various agents which were in operation chiefly during 

 the Glacial epoch that we must, as it seems to me, refer the ob- 

 literation of the volcanic craters of the north of Ireland. These 

 agents, indeed, were sufficiently numerous to exercise a most power- 

 ful effect in denuding the surface of the country. For, to the 

 ordinary action of rain and rivers, must be added at one time the 

 planing of an ice-sheet, and at another the levelling of the waves 

 of the sea. The glaciated surfaces of the basaltic rocks at Fair 

 Head and numerous other places attest the former presence of the 

 one ; while the beds of marine gravel, occurring especially in the 

 adjoining district of Armagh, up to elevations of 200 or 300 feet, 

 indicate the former presence of the other. 



The amount of denudation in the north of Ireland since the period 

 of the Miocene volcanos has indeed been enormous. Hundreds of 

 vertical feet of basaltic rocks have been removed, considerable 

 valleys, like those of Belfast Lough, Cushendall, and Bushmills, 

 liave been scooped out, and considerable tracts surrounding the 

 basaltic region have been stripped of their former covering of trap. 



Since the close of the Miocene period no volcanic outbursts have 

 taken place over the area of the British Isles. The fires of that 

 remarkable epoch have spent themselves here, and have retreated to 

 Iceland on the one hand, and the borders of the Mediterranean on 

 the other. Happily for us, we are not called on to witness the 

 entombment of a Pompeii, or the destruction by a fiery torrent of 

 a Catania. If these phenomena are to be vs^itnessed, it must be at 

 a distance from our own more fortunate Isles. 



V. — Note on a Small Eaised Estuarine Beach at Tramore 

 Bay, Co. Waterford, showing Traces of several Oscillatory 

 Movements during the Eecent Period. 



By Edward T. Hardman, F.E.G.S.I., F.C.S.i 

 Of the Geol. Survey of Ireland, Associate of the Eoyal College of Science, Dublin. 



(PLATE XL) 



WHILE spending a few days in the Autumn at Tramore, I 

 chanced to meet with a well-marked example of recent alter- 

 ation of shore-level ; and as on subsequent examination I find it only 

 partially noticed on the Six-inch Map, and not referred to at all on 

 the published One-inch Sheet, or in the Memoir of the Geological 

 Survey of the District, I thought of laying a short note on the 

 subject before this Society. 



The Bay of Tramore is separated by a long ridge of sand-hills 

 known as the Burrow — chiefly of aerial origin — from an extensive 

 muddy estuarine flat called the Backstrand, the result of the silt of 



1 Eead before the Eoyal Geological Society of Ireland, December 9, 1873. 



