288 On the Anticlinal Line of the London and Hampshire Basins, 



conveniently deep and illustrative section of this bed of creta- 

 ceous diluvium, long worked for road materials, is to be found 

 near Burford Bridge. The materials here are firmly impacted 

 and loosely cemented together, like the Brighton cliffs, by their 

 own carbonate of lime ; which gives an appearance, as at Brighton, 

 approaching to regular stratification. But there is nothing here 

 to remove this accumulation from the category of common cre- 

 taceous drift. Beds of this kind show themselves on the banks 

 of the Mole in the hollow way near the bridge on the Reigate 

 road ; and also on the verge of the gault in digging foundations 

 of houses at the foot of Reigate Hill. Shifting to the South 

 Downs country, the same appearances are to be found on the 

 abraded surface of the chalk near Chichester*. The Port-field 

 there has long been worked for angular flint mixed with chalk- 

 rubble ; and between that place and the Union house at West 

 Hampnet, there was some time since, and perhaps is still, a flint- 

 gravel pit the exact counterpart of the Dorking one, and com- 

 posed of the same materials as the diluvial beds there, and as 

 those on which Brighton is built. I may here observe, that it 

 was the great denudation of the chalk, and the spread of these 

 drifts along the flat country south of the Downs from Chichester 

 to Brighton, and the raised beaches of eocene shingles, which 

 gave early observers the idea of its being an ancient sea-bed, of 

 which the chalk downs were the border ; — a position perfectly 

 untenable. 



Before we quit the chalk downs and enter the denudation 

 below, we may observe that, although the escarpment of these 

 downs, north and south, seems to have been swept clean of flint, 

 it presents here and there some beds of rubble. The same may 

 be said of the ten'aces of the malm or upper greensand. But 

 the gault has a large sprinkling of flints, which sometimes lie in 

 considerable hollows, as recorded many years ago by Sir R. 

 Murchison in his account of Alice Holt under the Alton Hills f. 

 These belong properly to the cretaceous zone, and are often ag- 

 glomerated by oxide of iron derived from the stratum in which 

 they have been imbedded. The gault country forms but a narrow 

 strip at the foot of the Downs. So narrow is its outcrop in the 

 western part of Surrey, that it is sometimes intruded on by the 

 subcretaceous drift. But except in this line of countiy and in that 

 east of Lewes, where it ceases to be bounded by the high grounds 

 of the lower greensand, it exhibits very little more than angular 

 flints. 



[To be continued.] 

 * Sussex. t Geol. Trans., vol. ii. 2nd series, p. 100. 



