﻿MURCHISON FLINT DRIFT OF S.E. ENGLAND. 355 



of the subjacent clay is neutralized. Good crops of corn are thus 

 visible along this argillaceous zone, which otherwise would be occu- 

 pied by oaks only, or by weak grass. To the north of Lewes the 

 drift-zone is specially marked in the parish of Barcombe, by exhibit- 

 ing many chalk-flints, long ago well described by Dr. Mantell ; and, 

 as the fact has been cited by Sir Charles Lyell as the only excep- 

 tional case to the usual clean denudation of the Weald, I lately visited 

 the spot. 



The slopes and summits of the low undulations of the Weald Clay 

 at Barcombe are more or less covered with the usual brownish-red 

 loam and clay, in which flints, more acted upon by water than those 

 near Petersfield, and stained with various colours, lie at heights of 

 120 to 200 feet above the sea, and, as in the localities above cited, 

 are irregularly disseminated without any appearance of stratification. 

 In short, from Petersfield to East Bourn, where the drift becomes for 

 the most part an accumulation of clay or loam, I have nowhere seen 

 it exhibit signs of successive bedding ; but everywhere proofs of its 

 having been accumulated suddenly and tumultuously, whether it be 

 lodged on the Lower Greensand or on the Weald clay. 



Now, whilst the central dome of the Lower Wealden is, as before 

 said, void of all such drift and also of all extinct fossil mammalia, the 

 zone I have described is more or less characterized by them. Near 

 Petersfield, where the flints are not protected by any capping of loam 

 and clay, it would be hopeless to expect to find bones, which if 

 exposed for ages to the percolation of water must have perished. 

 But in the depressions south of Petworth near Burton, where they 

 were mentioned by Dr. Mantell, and at Hurston or Wiggenholt, 

 remains of fossil quadrupeds have been found under loam, including 

 teeth of an Elephant at the latter place*. 



At East Bourn, where the eastern extremity of this zone of drift 

 consists chiefly of clay and loam, a harvest of fossil mammalia has 

 been for many years obtained, and from it Dr. Mantell has already 

 cited Elephas primigenius, Hippopotamus, Cervus, &c. 



In the sequel we shall have to consider similar accumulations of 

 fossil mammalia on the northern side of the central dome and under 

 the escarpment of the North Downs. The woodcut, fig. 4, may 



Fig. 4. — Diagram, showing the general Disposition of the Angular 

 Drift when not covered by Clay or Loam. 



x. Drift (chiefly flints with some clinkers). 

 a.'. Intercalations of uniform fine sand in the drift. 

 /. Lower Greensand or other rock. 



* Mr. Martin showed me specimens of some of these when I last visited 

 Pulhorongh. 



