1904. Prakger. — Ro2ind about Lake Belfast, 143 



under consideration. Swanston and I^apworth, and sub- 

 sequently the Survey officers, have ehicidated the Silurian 

 series. Hume has produced an important paper on the Chalk. 

 Starkie Gardner and Sir A. Geikie have thrown much light on 

 the volcanic series : and S. A. Stewart, Joseph Wright and 

 others have worked out the fauna of the Glacial and Post- 

 glacial beds. All this work is duly referred to, and its results 

 assimilated in the ''General Description." 



The district is one which has always charmed the geologist, 

 on account of the great variety of rocks displayed — folded 

 Silurian slates, patches of Carboniferous and Permian rocks, 

 Bunter, Keuper, Rhaetic, Ijas, Greensand, and Chalk peeping 

 out from under the Eocene basalts, the largest lava-sheet in the 

 British Isles ; Glacial clays and sands, and a varied series of 

 Post-glacial beds. The surface-configuration, too, is such as 

 may well supply interesting studies to the glacial geologist. 



As regards the origin of the drift which is spread over the 

 greater part of the Belfast area, an opinion is expressed with 

 no uncertain voice : — "The boulder-clay is probably the direct 

 product of land-ice" (p. 49). The present writer is proud to 

 admit that for many years he followed the little band of 

 Belfast workers who have so stoutly advocated a great Glacial 

 submergence. But — it is no doubt the enervating effect of a 

 Dublin atmosphere — he now confesses to a sympath}^ with the 

 modern view, and even when confronted with Mr. J. Wright's 

 2,100 foraminifera to the ounce\ he makes no protest against 

 the statement that " the fossils are almost certainly derivative 

 like the boulders." If this confession be interpreted as fickle- 

 ness by some of his former co-workers, he can but consent to 

 be relegated to the list of northern erratics now stranded in 

 County Dublin. The reasons for the adoption of the land-ice 

 theory in this district are conveniently summarised (pp. 60-61) ; 

 and a suggestive remark follows : — " If at some future time 

 Belfast Lough were again invaded by an ice-sheet, we should 

 expect that its recent estuarine claj^s would be transported and 

 intermingled with glacial detritus in the same manner that 

 the Pre-Glacial and Early Glacial marine deposits have been 

 intermingled with the boulder-clay. The smaller shells and 



^ LN., xii., p. 179, and Pnc. B.N.F.C, 1902-3, p. iii. 



A 2 



