the London and Hampshire Basins. 287 



misgivings on this head, for he has allowed the elephant beds 

 their proper place and prominence in the chapter on diluvium. 



Dr. MantelFs description of these cliffs is perfectly faithful ; 

 and I have only to add, that they form an excellent type of the 

 passage of the tertiary into the cretaceous zone of drift. In the 

 composition of that portion of them which lies to the east of 

 Kemp Town, I imagine the sands to be derived from the plastic 

 clay ; the angular flints and chalk-rubble from the eroded chalk- 

 rock in the vicinity ; and the shingle bed or ancient beach at 

 the bottom belongs to the pre-eocene epoch, and is the beach of a 

 sea of which we now know nothing more, than that it beat upon 

 tjie chalk before the deposit of the tertiary formations ; and was 

 most probably the parent of the great shingle beds of the plastic 

 clay, of which so much has been said. 



The second, or Cretaceous Zone. — As before said, on drawing 

 nearer to the bare and abraded chalk-hills, the rounded gravel of 

 the tertiaries ceases to be a feature in the composition of drift ; 

 and although a few are to be found in the '^ vents '^ (? rents) and 

 fissures of the chalk, and some stragglers adhering to the rolled 

 clays and clay loams which still linger amongst the drifts of the 

 verge of the Downs, they give place to a plentiful coating, and 

 in some cases large accumulations of entire and broken flints ; 

 and here and there beds of loam and patches of chalk-rubble. 

 In the line of country to which these belong also, we find the 

 ^' grey wethers " or Druid sandstones, and the flint conglomerates 

 of the eocene sera, — witnesses of the demolition of the strata 

 which lay on the chalk before the catastrophe of elevation. 



It is scarcely necessary to say, that all the Down country 

 affords an ample display of this sort of drift. The largest accu- 

 mulations of flint are to be found where there appears to have 

 been the greatest amount of denudation, at the bottom of valleys, 

 both longitudinal and transverse. On the broad expanse of the 

 Hampshire chalk, the tops of some of the highest eminences, 

 which have escaped perfect denudation, afford loams with a few 

 remaining round pebbles. The Burghclere Hills, for instance, 

 above the sources of the Test, and the high grounds between 

 Andover and Micheldever*; and a few round pebbles are also 

 to be found in the flint gravel beds of the Candover Valley, and 

 in the loams round the northern borders of the Vale of Meonf. 

 To this zone also I refer two remarkable accumulations of drift ; 

 — the one consisting almost entirely of angular flint and strong 

 loam, at and in the neighbourhood of FarnhamJ; and the 

 other an equally important one of the same sort of flint, with 

 chalk- rubble and a very slight sprinkling of rounded pebbles, 

 near Dorking §, at the entrance of the Vale of Leatherhead, A 

 * Hants. t Hants. % Surrey. § Surrey. 



X2 



