732 ME. F. W. HARMER ON TILE CRAQ OF ESSEX. [NOV. I9OO, 



90 per cent., being blown up from the sea-bottom by gales of 

 wind. 1 



At present the coast of East Anglia is singularly destitute of drifted 

 shells. Except in the extreme north-western corner of Norfolk, 

 between Hunstanton and Wells, which is exposed to north-westerly 

 winds, one may walk along the beach for many miles and hardly 

 find a specimen. It is evident, therefore, that conditions other than 

 those of the present day must have obtained along the western shore 

 of the North Sea during the Newer Crag Period. When we cross 

 the North Sea to Holland, however, we find dead shells everywhere : 

 along the beach ; fringing the shores of estuaries ; and accumulating 

 in channels through which tidal currents no longer run. So 

 enormous is the amount of these debris that carts are constantly at 

 work removing them from the beach, and powerful steam-dredgers 

 dredging them from the estuaries, 2 to be burnt for lime. On the flat 

 sandy beaches of the open coast-line, as at the southern extremity of 

 the island of Texel, the shells lie, mixed with sand, in nearly hori- 

 zontal sheets ; while along the shores of estuaries, and against sand- 

 banks, and in channels of former bays now being silted up, the debris 

 (composed of fragmentary as well as of perfect shells) are more or less 

 obliquely-bedded. This accumulation of shelly sand is attributed by 

 Dutch geologists, and I think with reason, to the prevalence of gales 

 from the west. If this be so, it would seem that strong winds from 

 the east, rather than from the west, must have prevailed on the shores 

 of East Anglia during the Newer Crag Period. In a short paper 

 read before Section C of the British Association at Dover, published 

 in abstract only, 3 I gave my reasons, from a meteorological stand- 

 point, for thinking that such was probably the case, and I hope 

 hereafter to be able to deal more fully with the subject. It seems, 

 however, that in the conditions now existing in Holland we have 

 a counterpart of those of East Anglia during the Later Pliocene 

 Epoch, and may thus obtain an explanation of the means by 

 which so enormous a quantity of shelly debris then and there 

 accumulated. 



S. V. Wood, Jun. suggested in 1864 4 that the oblique bedding 

 common in the Red Crag indicates that it originated, to a great 

 extent, as a beach-deposit. 5 The frequent south-south-westerly dip 

 of the highly inclined laminae shows, however, that the Red Crag 

 could not have been wholly accumulated against the southern shore 

 of the North Sea while it was gradually retreating northward. The 

 tectonic movement which affected the Anglo-Belgian basin must, 

 therefore, have taken the form, not so much of a continuous sub- 

 sidence in one direction, and an upheaval in the other, as of a 



1 Christopher Claxton, Minutes of Evid. in Pari. Report on Harbours of 

 Refuge (1858) p. 98. 



2 About 3,600,000 cubic feet of these shells are dredged yearly, at one spot. 



3 Rep. Brit. Assoc. (1899) p. 753. 



4 Anu. Mag. Nat. Hist. ser. 3, vol. xiii (1864) p. 185. 



5 It is oblique rather than current-bedding that is characteristic of the Red 

 Crag. 



