H. H. Hoicorth — A Great Post- Glacial Flood. 267 



as it occurs in Picardy, thus : " The stratification presented by this 

 loam, as well when it covers the plain as when it is superimposed 

 on the diluvium gris of the valleys, leaves no doubt that it was 

 formed by running water, which could be none other, as M. Belgrand 

 has proved, than that of an immense inundation" {op. cit. p. 28). 

 Passing into Belgium, he describes its character in detail. He 

 argues strongly against the fluviatile origin of the deposit, and adds : 

 " The limons which are found on these heights could therefore owe 

 their origin to nothing but an immense inundation or diluvian cata- 

 clysm " [id. p. 30). 



He urges, as is the case in the Diluvium of France, that the shells 

 found on the highest points of the water-shed separating the basin of 

 the Haine from the neighbouring basins, consist entirely of terrestrial 

 shells. " If these deposits had been fluviatile, we should have had 

 some river shells in them, and the circumstance that we have here 

 only terrestrial shells may best be explained by a cataclysm which 

 covered the whole country and buried these shells in the limon con- 

 taining them" (id. 30). 



The conditions are in fact the same as those I have urged in regard 

 to the loess and the diluvium rouge of the French writers. All these 

 surface deposits seem to be subaerial, to represent the old land surface 

 of the period of the Mammoth, disturbed, re-arranged, and washed 

 like a mantle over hill and dale by a general inundation of water. 

 Where we find the Diluvium separated into two layers, the lower 

 one, as we have urged, seems clearly to represent the undisturbed 

 land surface, while the upper one shows evidence everywhere of 

 the violent action of water. 



Speaking of the date of the cataclysm, M. d'Acy says, "It was 

 Post-Pliocene, posterior to the appearance of man in our country, and 

 at least in its later phases posterior to the definite scooping out of 

 the valleys, for ' the limon ' which owes its origin to it descends 

 from the plateaux to the very troughs of the valleys and covers there 

 the pockets and layers of diluvium gris in which the bones of the 

 great Quaternary mammals and incontestable proofs of man's exis- 

 tence have occurred " (id. 34). Again, speaking of the " limon of the 

 plateaux " in the basin of the Haine at Spiennes and at Mesvin, he 

 says, " It has been deposited as we see it by diluvian waters posterior 

 to the appearance of man, and the last phase of the movement to 

 which the formation of the limon properly belongs took place 

 after the valleys had received their present shape" (id. p. 36). 

 Speaking of the limon at Mezieres at an elevation of 99 metres 

 above the sea-level, he tells us there have been found there in the 

 same deposit specimens of Succinea arenwria and Pupa muscorum., 

 molluscs which do not live under the same conditions, and conse- 

 quently the fact of their being found together in the same stratum 

 could only have resulted from the movement (i.e. the diluvial move- 

 ment) which deposited the limon itself (id. p. 50). 



M. d'Acy finally sums up the result of his elaborate and detailed 

 examination of the problem in this conclusion, " The limon of the 

 plateaux of the North of France and of Belgium was deposited by 



