36 Mr. P. J. Martin on the Anticlinal Line of 



of these tertiaries in the so-called London and Hamsphire basins 

 as areas of deposit*. It is not necessary to go over the grounds 

 for the proof of that which has long been admitted. It is well 

 known that Sir Charles Lyell long maintained a theory of the 

 rise and denudation of the Weald, on the like notion of the gra- 

 dual removal of the materials into the basins or synclinals on 

 either side. This is now withdrawn and another substitutedf, 

 which the author allows to be provisional and tentative, in part 

 at least. 



In the early essay to which I refer, I showed that the Weald 

 Valley had no existence during the deposit of the tertiaries, and 

 that consequently the area of these deposits was much greater than 

 the synclinals in which they are now found. What was the full 

 extent of that area it is not now necessary to inquire. There are 

 good gi'ounds for believing that it extended over all that is now 

 the south-east part of England, and also over a large part of the 

 adjoining continent. We know, too, that it must have been di- 

 versified with sea and dry land. Dry land could not have been 

 far distant when the flora of Sheppey was produced. And the 

 same may be predicated of the copious supply of fossil wood, the 

 ophidians, and the numerous mollusca of Bracklesham of a later 

 date. Be this as it may, a change comes over the scene ; — we 

 part with the pleasant climate of one, and the happy fauna of the 

 other ; the mountainous parts of Britain ai'e covered with gla- 

 ciers ; the south-eastern part of England and great part of the 

 north of Europe are occupied by an arctic ocean, and the glacial 

 period is established J. 



The arguments used to prove that the Weald excavation could 

 not have been in existence when the tertiaries on each side of it 

 were deposited, are equally potent in proof of the non-existence 

 of the same excavation anterior to the glacial period. A slight 

 examination of the phsenomena of surface arrangement and of 

 levels will determine these points, and show that the deposit of 

 the boulder drift was anterior to the date of the Weald Valley. 



The Arun, the river nearest Selsey on the Sussex coast, is a 

 tidal river up to Pulborough, fifteen miles inland. By the pro- 

 file of the counti'y here given, we see that the boulder drift 

 lies at Selsey high above the sea-level §. Without being over 

 nice in detail, we ai-e pretty well assured that if the water on the 

 coast always stood at high tide, the levels at Pulborough, and 

 hundreds of square miles beside, would be constantly flooded. 



It is obvious, therefore, that the glacial sea which deposited 



* A Geological Memoir on Western Sussex, &c., 1828. 



t Manual, p. 272 et seq. 



X Manuals and Sj'steins of Geology and Geological Journals, passim. 



§ Selsey is 26 feet above the sea. 



