1865.] FOSTER AND TOPLEY DENTIDATION OF THE WEALD. 463 



the land, as the lowest parts are at the river-gorges. This would 

 necessarily be the case if these transverse valleys were cut down by 

 running water, as hereafter described. 



(2.) The escarpments follow only the strike of the beds *, changing 

 their direction as the strike changes. The British islands, from, 

 the number of formations exposed, and their great extent of coast, 

 should furnish some examples of long lines of cliffs following the 

 outcrop of beds, if any ever occur f. But we find, on the con- 

 trary, that the sea cuts across all formations alike, quite inde- 

 pendently of the strike. It sometimes forms bays and indentations 

 where the strata are soft and easily worn away, but never runs up 

 the country along the outcrop of the beds. 



(3.) We never find accumulations of shingle or any other marine 

 deposit at the foot of the escarpments. Sir Roderick Murchison 

 has used this argument against the marine theory. In his paper 

 before alluded to, he says (p. 393), " There is not a single rounded 

 pebble along the lower edges of any of the escarpments that flank 

 the central Wealden ; still less does the tract contain any fragments 

 of marine shells ; whilst by far the greater part of the detritus is 

 just that which must have resulted from an action which left the 

 shattered debris in positions and conditions which no ordinary sea 

 could have done." " Again, all the fossils found inland are terres- 

 trial." 



The gravel at Barcombe, cited by Sir Charles LyeU t as an ex- 

 ample of marine drift, is undoubtedly a river-gravel of the Ouse. 

 It occurs near the jimction of two streams, and contains Wealden 

 pebbles. In this gravel Mammalian remains have been found §. 



Sir Charles LyeU, however, does not seem now to lay much stress 

 on the gravel at Barcombe as being proof of marine action, as he 

 omits any mention of it in his last edition. He also suggests || that 

 marine deposits may have existed, and have since been swept away by 

 atmospheric denudation, without conceding a very considerable power 

 to atmospheric agencies ; but as we shall show that " rain and rivers" 

 have efi'ected a very great amount of denudation, there can be no 

 reason, in the absence of positive evidence, for appealing to the 

 action of the sea for the formation of the escarpments, especially as 

 the other objections to the marine theory which we cite still hold 

 good. 



(4.) Prof.Ramsay has well pointed out that, if the Weald were now 

 submerged so as to convert the escarpments into cliffs, we should have 

 an arrangement of sea and land in which denudation could act but 

 very feebly. There would be a central group of islands surrounded 



* See Eev. O. Fisher " On the Denudation of Soft Strata," Quart. Journ. 

 GeoL Soc. vol. xviii. (186i), p. 3. 



t Mr. F. Drew, who mapped a large part of Kent, Surrey, and Sussex, had 

 remarked tliese facts, and in 1861, if not earlier, had rejected tlie theory tliat 

 the Clialk and Greeusand escarpments are due to marine denudation. — 

 C. L. N. F. 



+ ' Manual of Elementary Geology,' 5th edit. 1855, p. 287. 



§ Mr. Godwin-Austen, Quart. Journ. Geol. Soc. vol. vii. (1851), p. 288. 



II 'Elements of Geology,' 6th edit. 1865,p. 372. 



2l2 



