I902. The British Association in Belfast, 3^7 



chalk. The great feature of the north was, however, due to volcanic 

 eruptions of Eocene age. Owing to the immense outpouring of basalt 

 across the uplifted Cretaceous and earlier strata, the Counties of Antrim 

 and Londonderry include high igneous plateaux. The granite of the 

 Mourne Mountains was intruded in the same period of unrest, and the 

 pinnacles and rocky walls of the group were a sign of youth when com- 

 pared with the older granite areas in Ireland. The existing surface of 

 northern Ireland was determined by the falling-in and dislocation of the 

 volcanic country that once spread northward to the Faroe Isles. Lough 

 Neagh thus lay in a shallow basin formed during this epoch of subsidence 

 and decay. The long sea-inlets of the north and west originated about 

 the same time ; but Ireland, now cut off from the lost continent on the 

 north-west, became joined on to the growing continent of Cainozoic 

 Europe. The spread of ice in glacial times was marked by numerous 

 hills of gravel and eskers, especially in the central plain, where they 

 form green ridges rising from the bogland and the prairie. The oscilla- 

 tions of level between the glacial epoch and the present day finally left 

 Ireland cut off from Scotland, Wales, and England, with which her 

 fundamental geological structure so obviously connected her. It was 

 interesting to note that the most prominent features of her landscapes 

 at the present day depended on structures impressed upon the area far 

 back in Palaeozoic times. The paper was illustrated by lantern views 

 mainly by Mr. R. Welch, of Belfast, and Mr. Lawrence, of Dublin. 



The Chairman said they had to thank Professor Cole for his interesting 

 lecture. It was a great advantage to those who had not studied the 

 geology of Ireland specially, that they should have it sketched and pre- 

 sented so clearly. 



ON THE PROLONGATION OF THE HIGHLAND BORDER ROCKS 



INTO CO. TYRONE. 



BY G. BARROW. 



The subject was introduced by a brief account of the jasper and green 

 rock series occurring along the southern margin of the Highlands in 

 Kincardineshire. The author then proceeded to note the other occur- 

 rences along the Southern Highland border, and to speak of the similarity 

 to these of the rocks of Anglesey and North Wales. The evidence as to 

 the age of these rocks was referred to, and marking their widespead 

 outcrop near Pomeroy, he showed that they bore the same relation to 

 the Highland rocks as those in Kincardineshire ; that was to sa)% the 

 two series were separated by a persistent thrust plane. This had been 

 previously traced by Mr. M'Henry, though his work was not published. 

 The metamorphism of the series by granitic intrusions was briefly out- 

 lined, and the age of the various groups was discussed. Taking into 

 account the evidence from different areas, the author concluded that 

 the Highland rocks were the oldest, and were of Archaean age. The 

 jasper and green rock series, though newer, was most probably of pre- 



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