AKNIVERSAllY ADDRESS OF THE PRESIDENT. 155 



south-west end of the volcanic belt. The coast-line of County 

 Waterford, from Tramore westward to Ballyvoyle Head — a distance 

 of nearly fifteen miles — presents, perhaps, the most wonderful series 

 of sections of volcanic vents witliin the British Islands. No one 

 coming from the inland is prepared for either the striking character 

 of the cliff scenery or the extraordinary geological structure there 

 presented, for the country is, on the whole, rather featureless, and 

 much of it is smoothed over and obscured by a covering of drift, 

 through which occasional knobs of the harder felsites protrude. 

 The cliffs for mile after mile range from 100 to 150 or 200 feet in 

 height, and present naked vertical walls of rock, trenched by occa- 

 sional gullies, through which a descent may be made to the beach. 

 Throughout the whole distance agglomerates and felsites succeed 

 each other in bewildering confusion, varied here and there by the 

 intercalation of Lower-Silurian shales and limestones involved and 

 pierced by the igneous rocks. Hardly any bedded volcanic material 

 is to be seen from one end to the other. The sea has laid bare a 

 succession of volcanic vents placed so close to each other that it is 

 difficult or impossible to separate them out. A careful study and 

 detailed mapping of this marvellous coast-section is a task well 

 worthy of the labour of any one desirous of making himself 

 acquainted with some of the conditions of vulcanism during older 

 Palaeozoic time. 



At the east end of the section, black shales containing Llandeilo 

 graptolites, and calcareous bands full of Bala fossils, dip westward 

 below a group of soda-felsites and felsitic tuffs, which seem to lie 

 quite conformably on these strata. Here, then, we start with proof 

 that the volcanic eruptions of this locality began during some part 

 of the Bala period. But immediately to the west these bedded 

 igneous rocks are broken through by a neck of coarse agglomerate 

 stuck full of chips and blocks of shale, some of them a foot long, 

 with abundant fragments of scoriform and flinty felsites. Some 

 columnar dykes of dolerite cut through the neck, and a larger 

 intrusion seems to have risen up the same funnel. The bedded 

 tuffs appear again for a short distance, but they are soon replaced 

 by a tumultuous mass of agglomerates. And from this part of the 

 coast onwards for some distance all is disorder. 



The agglomerates are crowded with blocks of various felsites and 

 microgranites sometimes 18 inches in diameter, many of them 

 presenting the most exquisite streaky flow-structure. The 

 angularity of these stones and the abrupt truncation of their lines 



