PLIOCENE PEEIOD IN ENGLAND. 477 



tion, though probably not representing the height reached by the 

 submergence there, being the rather large patch on the summit of 

 Elean Hill, near Canterbury. Grravel also occurs on the chalk pla- 

 teau of Picardy up to elevations of 130 feet or thereabouts *, thus 

 showing the easterly fall of the line of submergence. 



From France northwards, through Belgium, the shore of the 

 Glacial sea seems to be very clearly marked by the Campinian sand, 

 a formation of littoral and partly subaerial (or Dune) origin, which 

 in some places is underlain by beds of rolled shingle, and in others 

 passes down into the beds of a foreshore f. This formation, by its 

 structure, seems to represent the gradual recession of the sea as the 

 land rose, and so to coincide with the gravel c and e described in 

 this memoir. 



From the more eastern part of Belgium the beds of rolled flints 

 shown in Dumont's map, and also described by Belgian, Dutch, and 

 French geologists, as inferior to the Campinian, appear, so far as 

 they can be shown to be marine J, to indicate the shore of the same 

 sea in this direction; and there can be little or no doubt that the 

 extensive formation of sand and erratics covering parts of Holland 

 and North Germany, to which these geologists give the term Dilu- 

 vian, is an accumulation of the same sea as that which I have traced 

 as spreading over England after the termination of the Eed Crag, 

 and into which also the flood-waters of the Rhine escaped during 

 the Glacial summers which gave rise, as they flooded the land near 

 the mouth of this river, to the Limon Hesbayen. 



Pebbles of quartz and quartzite are abundant in the gravel which 

 caps the contorted Drift on the Cromer Clifi" §, as are also in some 

 places the corroded fragments of marine shells. In varying propor- 

 tions these pebbles occur in all the gravels which I have described 

 afe high levels. They have been carried down successively in the 

 "Weald as the emergence and denudation of that region proceeded, 

 and are found there in gravels || several hundred feet below the 

 elevation up to which the gravels that I have been tracing show the 

 Weald to have been submerged. In the eastern part of the area 

 over which I have described these gravels as occurring at high eleva- 

 tions the flints are in excess of the pebbles of quartz and quartzite, 

 but in the western these proportions are reversed. The principal 

 source from which these quartz and quartzite pebbles have come 

 seems to have been the Triassic conglomerate which ranges through 

 Sheets 62, 63, 71, 82, and thence northwards, and against which 



* Barrois, in Proc. Geol. Assoc, for 1879, p. 31. 



t Vandenbroeck and Oogels, 'Ann. See. Malacologique de Beige,' vols. xii. 

 and xiy. 



I The Dutcb and Belgian geologists are not altogether agreed to what ex- 

 tent these " Cailloux roules " are marine or not. Anyhow the depression traced 

 in the present stage carried the sea of the Campinian over a portion of them. 



§ These gravels, though marked c in fig. VIII., because they originated at; 

 the commencement of the emergence, and continued as a series daring the 

 formation of the Chalky Clay, are no doubt partially coeval with the gravel of 

 the culmination of submergence, which is shown in the other figures as b'. 



II Topley and Forster, Quart. Journ. Geol. Soc. vol. xxi. p. 452. 



