48 The Irish Naturalist, [Feb. 



GEOLOGICAI. STUDIES IN THE NORTH. 



Messrs. R. Tate, Wm. Gray, Swanston, Wright, and Stewart, have 

 always been known to their brother-geologists by their active researches 

 in the field ; but the meeting of the Belfast Naturalists' Field Club held 

 on December 17th, 1895, deserves special comment, as affording so 

 remarkable a proof of the spread of geological observation in the north. 

 Miss Steen described the contents of a newly opened cave ; Mr. Robert 

 Bell gave the results of his patient search among the Silurian shales of 

 Pomeroy ; and Mr. A. G. Wilson detailed the geological features seen on 

 the great Galway excursion. But the paper requiring separate attention 

 is that by Miss S. M. Thompson, secretary of the geological section of the 

 Club, in which the series of excursions held by that section were 

 described, with the accompaniment of critical notes upon the districts 

 studied. 



The area covered by the field-work of the section, from Annalong to 

 Ballycastle, enabled the fourteen or fifteen excursions in themselves to 

 form an admirable /re^zj- of geology. As one reads the report, one sighs 

 to think of the hundreds of students to whom the subject is still one of 

 diagrams and text-books, and who have to study in regions far removed 

 from the enthusiastic guidance of Miss Thompson. On March 23rd, 

 glacial and marine post-Pliocene beds were visited, in a new sea-swept 

 exDOSure, at Ballyholme. The numerical work of the boulder-recorders 

 was continued ; and the submerged peat, intermediate in age between 

 the glacial and the "estuarine" clays, was found exposed on a second 

 visit. This study of " post- Pliocene diastrophism," as our Californian 

 friends term it, was completed by an excursion to the fossiliferous 

 boulder-clay on Divis, some 1,350 ft. above the sea- It is typical of the 

 energy of these northern workers that one unsuccessful visit was made to 

 this mountain-plateau during a storm, and was followed six weeks later 

 by a fruitful one under the guidance of Mr. Stewart, the veteran dis- 

 coverer of the deposit. Miss Thompson comments on the abundance of 

 chalk boulders at these high levels, far above their parent masses. One 

 would be glad to know how far the former chalk surface spread to east- 

 ward ; was the eurite of Ailsa Craig intruded into a highland of Cretaceous 

 rocks, on the lower and western slopes of which the basalt vents had 

 already opened ? The hardened chalk and northern igneous rocks 

 might then have come rolling down these slopes in glacial times, to 

 become mingled in the boulder-clays on the denuded surface of the 

 basalts. The frequent discovery of large blocks of the Ailsa rock in Co. 

 Down and Co. Antrim points to its having at one time formed a moun- 

 tainous and snow-covered mass comparable to the Mournes themselves. 

 There is always the possibility, however, that some of the riebeckite- 

 rocks have been derived from those in Skye : and the Belfast geological 

 section should endeavour to obtain from the Survey Office in London a 

 sample of the more northern variety, which should be kept, with a sec- 

 tion, for purposes of close identification. As to the Upper and Middle 

 Lias fossils, however, which form one of the most brilliant discoveries of 

 Prof Sollas and Mr. Praeger at Kill-o'-the-Grange near Dublin, I feel 



