1910-1911.] ,33 



Belemnite, also specimens of Belemnitella mucronata, Ananchytes 

 gibbns, A. ovatus, the cast of a Brachiopod, a fragment of 

 Inoceramus Crispi, and fragments of Sponges. The beautiful flow 

 structure exhibited by zeolitic bands in certain blocks of basalt 

 was noted, and the following minerals were obtained : — Chabazite, 

 Analcine, Calcite, and fibrous Natrolite. 



From the Chalk quarry the party proceeded to Craigahulliar 

 quarry, south-east of Portrush, where a beautiful section in the 

 upper basalt is exposed, showing a remarkably fine example of 

 columnar basalt passing upwards into tabular basalt. The 

 columns are slightly curved, but as perfect as those of the Giant's 

 Causeway. At first sight the difference between the columnar and 

 amorphous basalt gave the impression of two different flows, but 

 on closer examination no breach of continuity could be observed, 

 and the great difference in structure seemed to indicate only a 

 difference in the rate of cooling of the upper portion of the sheet. 



On returning to Portrush, the indurated Liassic beds were next 

 examined, under a heavy downpour of rain. The best exposure is 

 on the north-east side of the peninsula, nearly in front of the . 

 Midland Railway Hotel. Here the impressions of Ammonites 

 were obtained, but the rock is so hard and splintery they are 

 difficult to extract. The great alteration in the Liassic shales is due 

 to the intrusion of the Tertiary basalts in a molten state, with the 

 result that the shales became so baked and hardened as closely to 

 resemble the invading rock. 



The party returned to Belfast by the 8 p.m. train, after 

 enjoying an excellent tea at the Whitehouse Central Hotel. One 

 feeling of regret alone was felt, that the celebrated Portrush rocks, 

 instead of being preserved as a natural museum, are at present 

 invaded by rubbish, and partly effaced by advertisements. 



