ANNIVERSARY ADDRESS OF THE PRESIDENT. xlvii 



ton, appears to be perfect, with the exception that no organic remains 

 have yet been detected in Drift of Sangatte. 



I have now to direct your attention to an elaborate paper, ** On the 

 Distribution of the FUnt Drift of the South-east of England," by Sir 

 Roderick Murchison. 



In the first place the author makes the important remark, that the 

 central ridge of the district, consisting principally of Hastings Sands, 

 is entirely devoid of drift, and of the remains of the great land ani- 

 mals which are found in it in other localities. On the southern side 

 of the ridge, on the contrary, the Weald Clay and Lower Greensand 

 are frequently covered with Flint Drift, extending from Petersfield 

 eastward to the coast ; forming a continuous layer over considerable 

 surfaces, but in others more or less interrupted. It is also to be re- 

 marked, as a curious circumstance, that this Drift does not, unless in 

 a few insulated patches, extend over the Gault, Upper Greensand, 

 and Lower Chalk, to the foot of the Chalk-escarpment. Westward 

 it can be traced to the confluence of the North and South Downs, 

 near East Meon on the west of Petersfield. At that extremity it 

 consists of flints, but more eastward about Trotton Common, hard 

 pieces of Iron-stone and Chert, from the Lower Greensand, are added 

 to it. The flints are splintered, sharp, and unworn. As we ap- 

 proach the eastern extremity of this zone of Drift near Eastbourne, it 

 contains a large quantity of loam and clay. It is in these portions 

 of the mass that the remains of extinct mammalia are principally 

 found. The greatest height to which the Drift here attains is on 

 Rogate Common about 500 feet above the sea. 



The author considers the flints of this mass to have been derived 

 from the Chalk, west of Petersfield, from whence they have been 

 carried eastward by a powerful current, the tract having been pre- 

 viously submerged to the required depth beneath the sea. He thinks 

 they cannot have been derived from the parallel Chalk-escarpment 

 of the South Downs, on account of their absence in the intervening 

 zone of Gault and Upper Greensand. Admitting, however, the 

 easterly course of the transporting current, it would seem still very 

 difficult to understand why the flints should not have been spread by 

 it over the Gault in the lower part of the valley along the foot of the 

 Chalk-escarpment, which must have directed the course of the current. 

 It would seem to me more probable that the lower zone along the 

 Gault might be left under water while the higher zone of the Lower 

 Greensand along which the Flint Drift is now distributed was, soon 

 after the deposition of the Drift, elevated into dry land. In such 

 case the ordinary denuding action of the sea, aided probably by cur- 

 rents of elevation, might again denude the Gault of its superincum- 

 bent Drift. According to this hypothesis, it would not be necessary 

 to adopt the author's notion that all the flint-debris has been derived 

 from the Chalk at its western extremity. It may have come in part 

 from the neighbouring escarpment. But from whatever source it 

 may have been derived, I entirely concur with the author in believing 

 that angular flints, often as sharp as gun-flints, could not have been 

 deposited in the state in which we now find them, by the ordinary 



