162 MK. A. J. JUKES-BROWNE ON [May 19°^» 



EXPLANATION OF PLATE VI. 



Fig. 1. Section acrcss Salisbury Piain and the Alderbury syneline. (See p. 150.) 

 2. Section from near Braishfield through Farley Down. (See p. 153.) 



Discussion. 



Prof. Boyd Dawkins said that he fully accepted the general 

 conclusions at which the Author of this very interesting paper had 

 arrived. The Clay-with-Flints was the result of the destruction of 

 beds which were mainly, but not exclusively, Eocene. He (the 

 speaker) had explored beds of similar nature and origin in the 

 country round Chartres. The analyses cited by the Author agreed 

 precisely with those which the speaker had made many years ago : 

 in the lowest beds of the Lower Chalk the percentage of insoluble 

 residue was the highest, diminishing from 20 to 5 per cent, as one 

 approached successively-higher horizons. Very likely, the Clay- 

 with-Flints was the outcome of work performed by geological 

 agencies both during, before, and after Pliocene and Pleistocene 

 times. 



The Rev. Edwin Hill enquired whether anything in East Anglia 

 represented the Clay-with-Flints. If it was absent, the presence 

 of Eocene Beds might support the views of the Author. 



Mr. H. W. Monckton said he thought that no one could regard 

 the deposits which it has been found convenient to map as Clay- 

 with-Flints as, in the main, a residue from the slow solution of the 

 Chalk : they undoubtedly consisted very largely of debris of Eocene 

 strata. It appeared to the speaker that an explanation of the origin 

 of the Clay-with-Flints, in order to be quite satisfactory, should 

 also cover the deposits of brickearth which seemed to be so closely 

 associated with the Clay-with-Flints, and reached an imposing 

 thickness on the plateaux near Great Hampden and Caddington, 

 for example. 



Prof. Sollas said that he cordially congratulated the Author, and 

 fully agreed with his results, which had anticipated his own. In 

 support of them he cited the deposit at Stokenchurch, where the 

 Clay-with-Flints contains fragments of Tertiary brown sandstone 

 (identical with that of Nettlebed) ; also the occurrences in the 

 neighbourhood of Ewell, where the Clay-with-Flints is seen to 

 overlie Tertiary strata. 



Mr. A. S. Kennaed said that his own observations on the North 

 Downs entirely confirmed the Author's conclusions : but he could 

 not admit that the Glacial Period had anything to do with the 

 formation of the Clay-with-Flints, which must be earlier than 

 the existing valleys. 



Mr. G. W. Young expressed his difhdence in addressing the 

 Fellows on the evening of his introduction to the Society, and said 

 that he only ventured to do so, because the subject was closely 

 connected with the theory of dry Chalk- valley formation which he 

 had advocated before the Geologists' Association in June last. He 

 welcomed the Author's conclusions, because they strongly confirmed 

 his own suggestion that a clay-sheet was once continuous over the 



