WALTON-COMMON SECTION. 



455 



In this way a species of speculative stratigraphy is encouraged) 

 which has no real foundation except in similar misconceptions. 

 Thus, true progress towards a correct understanding of the history 

 and constitution of the London Basin is retarded. 



With reference to the subject of mapping, if it is proposed that 

 all argillaceous outcrops shall be coloured as Middle Bagshots, that 

 is a question which must be settled elsewhere. But if this is the 

 view taken by the authorities in charge of these matters, it 

 obviously implies a reclassification of the entire Bagshot system. 



Discussion. 



The Peesident congratulated the Author on the light he had 

 thrown on the relations of the Eocene beds near Weybridge. He 

 thought that the lenticular character of the beds of this age in both 

 the Hampshire and London basins had been clearly shown. 



Mr. Whitakee said Mr. Hudleston's section of the Hatch-Farm 

 Claj'-pit suggested a synclinal, though probably the hollow was one 

 of erosion. 



The junction of the London Clay and the Bagshot Beds in the 

 Walton-Common section was singularly abrupt ; as a rule those 

 formations passed into each other. The term Bagshot Beds was 

 preferable to Bagshot Sands, for the character varied. There was 

 more clay to the west, in the Hampshire Basin, and especially in 

 Dorsetshire. 



Mr. Irving gave some details of a section at Highclere to show 

 the transition between London Clay and Bagshot. The section 

 through Woburn Hill, if drawn to true scale, would show the 

 synclinal to be very shallow. The Hatch section appeared to be a 

 mere case of "contemporaneous erosion and filling up." 



Mr. Heeeies said he had seen no clays in the Bagshot Beds 

 like those of Woburn Hill ; but they resembled the basement bed of 

 the Middle Bagshot more than any others. He was, however, in- 

 clined to think Mr. Hudleston's conclusions were right, but thought 

 judgment should be suspended till the nature of the upper part of 

 the hill was known. It had been said that the chalk surface and 

 the beds above it were irregular ; if so, there might be a local syn- 

 clinal here, quite distinct from the general basin-shape of the dis- 

 trict. Again, clay conditions might have set in earlier here, so as 

 to cause a great development of Middle-Bagshot clays at the expense 

 of the sands of the Lower Bagshot. He agreed with Mr. Hudleston's 

 view of the Walton-Common section. 



Mr. Hudleston said the suggestion of a great development of 

 Middle Bagshot was difficult to prove or disprove. The curve made 

 by the Thames at this point might, however, be due to a depres- 

 sion of the Bagshots. The presence of passage-beds in a different 

 district, as described by Mr. Irving, did not necessarily throw any 

 light on the conditions prevailing near Weybridge. In some cases 

 the clays of the Lower Bagshots might have been mistaken for 

 London Clay. 



