Geological Society. 73 



east, were apparently formed at a time when the level of the Trent- 

 valley area was lower than that of the Cretaceous tracts in Lincoln- 

 shire and Yorkshire. The Great Chalky Boulder-clay was chiefly 

 a ground-moraine formed beneath an ice-sheet on land, but in places 

 presented signs of aqueous origin. The Melton sand, below, in 

 which Cretaceous detritus first appeared in abundance, consisted of 

 stratified sands with occasional beds of gravel or loam, and indicated 

 a less extreme temperature. In West Staffordshire the gravels and 

 sands probably represented the entire Middle Pleistocene deposits, 

 no great Chalky Boulder-clay being found, and in this area frag- 

 ments of marine mollusca were of frequent occurrence. The Chalky 

 Gravel was also a marine deposit, and, like the Melton Sand, was 

 probably formed when the temperature was rather milder than it 

 was during the deposition of the Great Chalky Boulder-clay. 



In the Newer Pleistocene epoch re-elevation of the Trent valley 

 and of the Pennine chain appeared to have again produced a change 

 in the direction from which the materials of the deposits were 

 derived. The Interglacial Alluvium was of freshwater origin, but 

 the admixture of Scotch and Cumbrian detritus with that derived 

 from the Pennine range indicated that glaciers from the north 

 again reached the Trent area. A colder age succeeded, during 

 which the Later Pennine Boulder-clay was formed, partly of local 

 materials, partly of erratics from the Pennine range, mixed with a 

 few from Cumberland and even from Wales. This deposit was 

 almost entirely unstratified, and consisted largely of moraine detritus, 

 the ice-sheets having disturbed and rearranged the earlier deposits 

 and mixed them with rock- detritus from the neighbourhood. To 

 this later ice-sheet was attributed the contortion so frequently 

 observed in the older and middle Pleistocene deposits. Reasons 

 were given for the opinion that such contortions were due to ice- 

 and not to soil-cap motions or their later agencies. 



5. " On the Existence of a Submarine Triassic Outlier in the 

 English Channel off the Lizard." By R. N. Worth, Esq., E.G.S. 



Attention was called to the frequent occurrence of sandstone 

 fragments in a certain part of the English Channel, brought up by 

 the fishermen's " long lines." The evidence favours the idea that 

 these rocks are in situ. 



A list of the specimens found, with bearings and distances, was 

 given ; they consist of red, and sometimes greyish sandstones, 

 mostly soft, also marls, " potato stone," and nodules of Triassic 

 trap. The affinities are with the Keuper of Devon. The position 

 deduced from the observations is about 10 miles S.E. of the Lizard, 

 and beyond the 30-fathom line. This submarine outlier is larger 

 than any outlier on the mainland of Devon or Cornwall, and carries 

 the English Trias nearly 50 miles further to the S.W. 



April 21.— Prof. J. W. Judd, E.R.S., President, in the Chair. 



The following communications were read : — 



1. " Further proofs of the Pre-Cambrian age of certain Granitoid, 

 Felsitic, and other Rocks in North-western Pembrokeshire." By 

 Henry Hicks, M.D., F.R.S., E.G.S. 



