the London and Hampshire Basins. 281 



nutely described by Dr. Fitton*, the lower one only presents an 

 abrupt and rocky escai'pment. With some interruptions, this 

 kind of outcrop is continued for many miles together round the 

 west end, and along the north and part of the south sides of the 

 Wealden area. It is to these parts of its course I now direct 

 the observer's attention. Wherever sections in these rocky 

 escarpments offer themselves, a tumultuous and tortuous disposi- 

 tion is to be seen penetrating deeply into them, behind their 

 ordinary coating of alluvial and diluvial rubble. Railway cut- 

 tings have sometimes brought these into view ; but better exam- 

 ples may often be found in the stone quarries, and would be still 

 more frequent, if it were not so often found more convenient and 

 more profitable to go further back to extract the stone, out of the 

 way of the ^Mebris'^ above mentioned. There are no better 

 examples of the tumultuary and contorted appearances of which 

 I am now speaking than are to be observed in the outskirts and 

 approaches to the stone pits by the Medway in the Maidstone f 

 country, where much broken material and unprofitable detritus 

 (in which large rock-masses lie loose, and are crumpled and 

 tossed about) have to be removed before the undisturbed rock 

 can be got at. It is on this account also that the " Fire-stone '* 

 (the plateau of the upper greensand) is generally quarried by 

 shafts sunk near or even through the chalk ; as was anciently 

 the case at the MersthamJ quarries, and as is now done at Rei- 

 gate Hill. But I remember inspecting a quarry many years ago 

 opened by Alderman Waithman at Ray Common, near the latter 

 place, and worked by an open adit, in the entrance to which, to 

 the extent of twenty or thirty feet or more, the rock -masses lay 

 in great disorder, broken up and contorted in situ, and not in 

 the manner of the blocks and broken materials of the talus of a 

 sea-cliff. Such cases as these might be multiplied from all around 

 the escarpments of the area under review. 



There is another appearance, and one much more conclusive 

 as to the violence of the diluvial action to which these escarp- 

 ments owe their existence, which is to be found under favourable 

 circumstances at the angles of the cross fractures described in 

 the foregoing pages. In the imperfect description given in my 

 earliest memoir on this subject, of the course of the river Arun 

 through the greensand escarpment at Pithingden near Pul- 

 borough §, I spoke of a remarkable slide of the stony strata on 

 the east side of the gorge-like valley down toward the river, 

 which at that place takes its course in the Weald clay beneath. 

 It is to this extraordinary appearance Mr. Hopkins alludes, 

 p. 17 of his Memoir on the Structure of the Weald, published, 



* Trans, of Geol. Soc, vol. iv. 2nd series. t Kent. % Surrey. 



§ Geol. Memoir on Western Sussex, pp. 66, 67. 



