J. W. JTTDD ON THE SECONDARY ROCKS OF SCOTLAND. 743 



lately declared its fossils to be those of a comparatively shallow sea. 

 He also asked whether the Chalk in the district described was like 

 that of the north of Ireland. 



Mr. Sollas remarked that the outlines of land and sea were of 

 first-rate interest to the geologist ; and inquired whether a broad gulf 

 of waters stretching across the Triassic plains of Cheshire and Lan- 

 cashire, and over the North-east of Ireland and the North-west of 

 Scotland, would not account for the facts without assuming a very 

 general submergence of the British Isles. It seemed to him that to 

 say from the present absence of Oolitic beds over large areas that 

 such beds had never been was more philosophical than to deduce 

 from it their former existence. In support of his opinions he indi- 

 cated that in the south-west the Carboniferous land had a fringe of 

 New Red Sandstone, and the Lower Lias had no Oolite over it. In 

 the South-west there was evidence of shallow water close to a coast- 

 line. It seemed to him that the absence of sedimentary beds proved 

 that there had been no submergence. With regard to the Jurassic 

 period, his notion was that all Wales, Devonshire, Cornwall, and the 

 Pennine chain have been above water since the time of the Lower 

 Lias. 



The Author, in reply, said that Prof. Hamsay and Prof. Hughes 

 seemed to think he ought to have approached his subject from their 

 standpoint rather than from his own. All will agree that the Lias 

 and the Chalk were not formed in lakes. Fragments of lavas occur 

 throughout large areas ; and under all of these the Secondary rocks 

 are preserved. If they were not originally continuous across the 

 existing gaps, we must assume that the sea went exactly to these 

 limited spots, which was so unlikely as to be almost absurd. In 

 reply to Mr. Whitaker, he said that the evidence was in favour of 

 the Cretaceous nature of the beds, but the proof that they were not 

 Eocene was not absolute. The basaltic lavas were Miocene, the 

 others Eocene. The relations of lavas to the beds beneath them 

 had been dealt with in a former paper. To Mr. Woodward he said 

 that the Antrim lignites are not Cretaceous, but Tertiary ; to Mr. 

 Blake, that all the beds are not estuarine, but there are immense 

 thicknesses of marine deposits with fossils ; and to Mr. Sollas, that 

 he preferred at present dealing with the ascertained facts, reserving 

 the treatment of the theoretical questions involved for a future 

 paper. 



