32(3 Reports and Proceedings — 



degradation of the Weald to the south, and of East-Mercian England 

 to the north-west, this period of waste of the Cretaceous rocks 

 having furnished much of the rnatei'ials which, in Pliocene times, 

 were carried across a sloping plateau by fluviatile agencies. 



The composition and structure of the plateau-gravels are next 

 described, reference being made to previous writings of Prof. Rupert 

 Jones and to the recent papers of Prof. Prestwich. Reference is 

 also made to the explanation suggested by the author seven years 

 ago of the anomalous contrast presented by the lithological conditions 

 of the flint-pebbles and the subangular flint-fragments which are 

 intermingled in these gravels. The great masses of unstratified and 

 unrolled flint debris on the Aldershot Hills are compared with the 

 Preglacial " Schotter " of the lower Alpine valleys. The plateau- 

 gravels are described as occupying altitudes ranging from nearly 

 600' (O.D.) at Aldershot and on the north side of Netley Heath, 

 down to 280' (O.D.) at Bearwood and Farley Hill. A list of 22 

 localities (with altitudes) is given where actual sections of the 

 plateau-gravels can be studied. 



Evidence of glacial action at lower levels (210' to 240' O.D.) is 

 then given, sections being described at Nine-mile Ride (Old Windsor 

 Forest), Wokingham, and Sunninghill, and apparent evidence of 

 glaciation at Bracknell, Warfield, and Finchampstead. Photographs 

 of some of these sections are given, and the levels of the plateau- 

 gravels and the glaciated sections correlated by a sectional diagram. 



The author concludes, from the evidence given in the paper, that : 



1. The Plateau-gravels are of fluviatile origin, their materials 

 having been transported from the Weald-region to the south. 



2. They mark roughly the ancient lines of Pliocene drainage of 

 an old elevated Tertiary region, the present valley-system having 

 been mainly determined by their absence. 



3. That the modern Lower Thames Valley was initiated in Plio- 

 cene times, the main line of drainage having been somewhat further 

 north than at present. 



4. That attention to altitudes reveals the fact that the present 

 valley-system was outlined and the major part of it actually exca- 

 vated in an interval that intervened between the age of the Plateau- 

 gravels and the Glacial Epoch. 



5. That the deposition of the Plateau-gravels probably covers 

 most of the geologic time represented by the Pliocene. 



A note is added on the probable progressive elevation of the 

 Weald from west to east. 



3. " Further Note on the Existence of Triassic Rocks in the 

 English Channel off the Coast of Cornwall." By R. N. Worth, 

 Esq., F.G S. 



A specimen of Triassic conglomerate trawled seven miles south 

 oftheDeadman headland, arid several miles east of the previously 

 recorded Lizard outlier, is described, and reasons given for its occur- 

 rence in situ. It contains pebbles of slate, grits, vein-quartz, quartz- 

 felsite, and andesitic rock. 



