Wealden Petrology : The Top Ashdown Pebble Bed and the Top Ashdown Sandstone

From Mr. F. H. Edmunds :— After the publication of the above paper, the author was asked if he would demonstrate, over a selected route, the field evidence for his fundamental conclusion that the Top Ashdown Pebble Bed is a single Weald-wide stratigraphic unit, and not a series of lenticular pebble-beds at varying horizons. On this conclusion, of course, the validity of his whole argument depends. He very kindly agreed to do so, and a route embracing Cowden, Penshurst, Wadhurst, Rotherfield, Burwash, Dallington, Battle, Crowhurst, Westfield, Brede, Robertsbridge and Hurst Green (traceable by reference to fig. 2, p. 268 of the paper) was chosen. Numerous sections—at least one in each of these localities—were examined, all at the junction of the Wadhurst Clay and Ashdown Sand as shown on the one-inch scale Old Series Geological Survey maps. Without exception, Dr. Allen was able to demonstrate the presence of a well-developed pebble bed, varying in thickness from an inch to nine inches and in most instances associated with the swamp soil-bed, containing many rhizomes and stalks of Equisetites lyelli , as described in his paper. Dr. Allen's evidence is clear, for all to see; and his correlation of the various sections—in making which much other field evidence was taken into count, and by virtue of which he concludes the Top Pebble Bed to be everywhere one and the same—is, in the writer's view, fully justified. The combined occurrence of the Top Pebble Bed, the overlying swamp soil-bed and the Neomiodon medius shell-bed should