DILUVIUM. 275 



XIX. 



§ IV. 12. DILUVIUM. 



IiiREGULAB accumulations of clay, sand, and gravel, intermixed with 

 broken chalk flints, are every where indiscriminately distributed over the 

 surface of the country, and obscure the outcrops of the regular forma- 

 tions. These depositions are evidently composed of the ruin of the more 

 ancient strata ; and in all probability have been produced by that last ca- 

 tastrophe, by which the vaUies have been excavated, and the hiUs moulded 

 into their present form. 



Of these deposits, the detritus of the chalk in a state of calcareous 

 loam, broken flints, and gravel, constitute by far the most considerable 

 portion; and so extensive is the destruction to which that formation has 

 evidently been exposed, and so universally are its ruins distributed over 

 the Weald of Sussex, as to warrant the conclusion, that it formerly ex- 

 tended very far beyond its present limits. 



On the summits of the Downs, a layer of flints, slightly rolled, appears 

 immediately beneath the turf, resting on an inconsiderable layer of chalk 

 rubble. This bed contains rounded masses of chalk, crystallized car- 

 bonate of lime, ferruginous breccia, scoriaceous ironstone, a coarse grit 

 containing angular fragments of quartz, and flattened oval pebbles of 

 druid sandstone. The flints are more or less broken, have suffered but 

 little from attrition, and are so abundant, as to form a constant supply for 

 repairing the roads in the south-eastern part of the county. This bed 

 has clearly been formed by the destruction of the upper portion of the 

 chalk ; and it is equally evident, that the cause which produced the ruin 

 of the superior strata, was as transient, as it was powerful ; since although 



