286 Mr. P. J. Martin on the Anticlinal Line of 



the ordinary way we usually understand the formation of sedi- 

 mentary beds, from a sea of the range and extent of which we 

 cannot now have any possible conception, then I unhesitatingly 

 affirm that no such deposit, or relic of such deposit, is to bo 

 found in any part of this area. 



The first, or Tertiary Zone, ranges all along the edges of the 

 plastic clay as they basset on the chalk, and contain everywhere 

 a large admixture of the shingle which abounds so much in that 

 stratum. As the bare chalk begins to appear, angular flint is 

 largely added ; and finally angular flint alone is found on the 

 chalk, and the rounded pebbles disappear, except here and there 

 a few stragglers. 



This change from pebbly drift to broken flint may be conve- 

 niently studied on the verge of the North Downs, on Walton 

 Heath*, between the Addington Hills f and the chalk escarpment, 

 and in all the outcrop of the tertiary beds, to the Darent. Similar 

 observations may be made along the same outcrop to the Basing- 

 stoke J and Odiham country. I have not examined this outcrop 

 to the north of the Pewsey line, but I do not doubt of finding a 

 similar interchange of rounded pebbles for broken flints there 

 also. 



Crossing the Hampshire and Wiltshire chalk, we find the same 

 pebbly . drift from Salisbury to Michelmarsh on the Test and 

 Ilomsey§ ; and we meet it again on the northern borders of the 

 Forest of Bere, mixed with a very large proportion of flints in 

 the gravel pits at Horn-dean and Rowland's Castle ||. Eastward 

 from Bere Forest, where we enter on the line of country south 

 of the South Downs, so great has been the destruction of the 

 chalk, that the cretaceous or flint zone falls in and almost excludes 

 the pebble beds. Nevertheless they appear in force at Box- 

 grove^, more sparingly along the flat country towards Arundel, 

 but again strongly at Clapham and Patching, north of Highdown 

 Hill, and still prevail along the Worthing and Shoreham vicini- 

 ties, till they are cut ofi" by the Brighton cliffs. 



The section of the diluvial beds given by the Brighton cliffs, 

 from Copperas Gap to Rottingdean, possesses much interest, be- 

 cause it includes deep masses of drift, composed of chalk-rubble, 

 angular flints, and sand and shingle of the eocene epoch, so com- 

 mingled as to have led the historian of the " Geology of the Souths 

 east of England '' into the belief that they were stratified beds 

 of the jera of the crag. To these he has given the name of 

 '^ Elephant beds**," because they yielded the bones of elephants 

 and other mammals. But Dr, Mantell seems to have had some 



* Surrey. f Surrey. J Hants. 



§ Hants. II Hants. If Sussex. 



♦* Geol. of the S.E. of England, by Gideon Mantell, F.R.S., 1833. 



