G. W. Lamplugh — Age of English Wealden Series. 443 



'head' and the overlying Drift. The latter is full of rounded stones 

 of Carboniferous Sandstone and Old Ked pebbles and fragments, 

 with scarcely a trace of limestone, whilst on the contrary the under- 

 lying debris contains nothing but fragments of limestone. The 

 change is exceedingly sudden, and forbids the possibility of the 

 Drifts resting on the cliffs for long previously, and later slipping 

 down on to the debris. Scattered boulders would certainly have 

 occurred in the debris. 



The Drift is evidently the ordinary Glacial Drift of Glamorgan- 

 shire, such as abounds further to the north-east, nor can we doubt 

 that it is about the same age as that which sealed up in the Victoria 

 Cave at Settle, and other caves, the fauna which has been so 

 abundant in the caves of Gower, a fauna which if not Pre-Glacial 

 was certainly Interglacial. 



On the other hand, the discovery of the antiquity of the raised 

 beach, which does not appear to have been even hinted at, is one 

 which, from the wide range of that physical feature, must necessarily 

 be of importance. It will assist in building up the relations of late 

 formations to the Glacial Period into a consecutive system, and 

 establish relations with other successions in lands to which Glacial 

 phenomena have not extended. 



IV. — Note on thk Age of the English Wealben Sekies.^ 

 By G. W. Lamplugh, F.G.S., of H.M. Geological Survey. 



N recent discussions arising from the renewed attempts to define 

 more closely the boundary between the Jurassic and Cretaceous 

 systems in Eussia, Germany, Belgium, and France, and also in North 

 America, constant reference has been made to the English Wealden 

 deposits as affording a standard of comparison. But, meanwhile, 

 doubt has been thrown, by palceontologists who have studied certain 

 portions of the Wealden flora and fauna, on the hitherto accepted 

 classification of these English deposits with the Lower Cretaceous, 

 on the grounds that the fossils showed strong Jurassic affinities. 

 This opinion has been expressed by the late Professor 0. C. Marsh 

 in regard to the reptiles, by Dr. A. Smith Woodward in regard to 

 the fish, and by A. C. Seward in regard to the plants. To prevent 

 further confusion it is therefore desirable that certain facts which 

 have been overlooked in this discussion, though for the most part 

 already published, should be restated, since these facts seem sufficient 

 to prove that, at any rate, the greater portion of the English Wealden 

 series must remain as part of the Lower Cretaceous. 



It has not always been sufficiently borne in mind that the accumu- 

 lation of the Wealden Series must have required a period of very 

 long duration. The sands of the Hastings Beds may indeed have 

 been deposited rather rapidly, but the shaly clays, with layers of 

 shells and cyprids, interstratified with these sands, indicate slower 

 sedimentation, and the great mass of Weald Clay, reaching 1,000 

 feet in thickness, must represent an epoch of great length. Hence, 



' Read before the British Association, Section C (Geology), Bradford, Sept., 1900. 



