190 Mr. P. J. Martin on tfie Anticlinal Line of 



1. The general arrangement or geographical aspect of the 

 country. 



2. Its valleys, and lines of di-ainage. 



3. The lacerated state of some of its escarpments, still to be 

 discerned behind the detrital materials of age, and atmospheric 

 agencies. 



4. The nature and disposition of the diluvium on every part 

 of its surface. 



The first of these is so familiar, in a general sense, and has 

 been so often described, that it would seem superfluous to take 

 it into consideration ; — and yet it will be well to cast a geological 

 eye over it. If we take our stand on the lowest beds of the up- 

 heaval, say at the well-known point of Crowborough, on the 

 Ashburnham limestone (supposed by Dr. Mantell to be the 

 lowest in the series), or on the sand rocks of Hastings, we find 

 all around us a quaquaversal dip ; a succession of escarpments 

 or basset edges, confluent at either end; — westward in Sussex 

 and Hampshire, eastward in the Boulonnais. The successional 

 courses of clays, sands and limestones of the Hastings sands, 

 after skirting the " Forest ridge,^' form saddles in the west of 

 Sussex. To these succeed the lower greensands, the gait, the 

 malm-rock or upper green, and the chalk; afterwards the 

 tertiary beds, still confluent above the Hampshire chalk, in 

 the shape of patches of plastic clay and sand ; and the gray- 

 weathers of the Hampshire and Wiltshire downs ^'. Turn- 

 ing to the east, we find that this confluence is maintained in like 

 manner in all the beds of the Bas Boulonnais ; substituting the 

 more ancient formations, which take the place of the Wealden 

 (there reduced to a very small compass). And this confluence 

 is maintained there also in the tertiary beds, as in Hampshire, in 

 the shape of relics spread over the chalk hills of the surrounding 

 Haut Boulonnais. These facts are pretty well known; but for 

 the satisfaction of those who have not turned their attention 

 especially to this subject, we may cite the authority of the French 

 geologist, M. Rozet, who in 1828 followed Dr. Fitton in a de- 

 scription of this part of France. " On rencontre des lambeaux 

 de terrain tertiaire sur les montagnes qui limitent le Bas Bou- 

 lonnais. Au dessus de Tingry, de Niembourg, pres d'Huber- 

 sent, de Courset, &c., on exploite des lambeaux d'un gres sili- 

 ceux, tres-semblable a celui de Fontainebleauf/' &c. M. Rozet 

 also speaks of the same sort of remains found dispersed in the 

 diluvium of the Boulogne denudation ; to which we may refer 



* Vide Dr. Buckland's paper (Geological Transactions) and my foregoing 

 Memoir. 



t Description G^ognostique du Bas Boulonnais. Par M. Rozet. Paris, 

 1828, p. 31-36. 



