Yol. 56.] ME. F. W. HAEMEE ON THE CEA.G OF ESSEX. 737 



Walton cliff-section (fig. 2, p. 711), with the gravel of Clacton, a few 

 miles to the south, may possibly belong to a subsequent stage of the 

 Crag, when the Walton area had been slightly elevated, and was 

 occupied by the embouchure of the river before referred to, the Crag 

 sea having retreated into Southern Suffolk, destroying as it did so 

 any Older Pliocene beds which may have existed there, except the 

 littoral deposits of the Coralline Crag sea with their derivative 

 fossils, which were reconstructed so as to form the basement-beds 

 of the Newbournian Crag at Waldringfield and elsewhere. 



The Newbournian stage is separated from the Waltonian, not 

 only by the time required for the tectonic movement which carried 

 the Crag sea into Suffolk, but for the arrival in the Crag basin of 

 further immigrations of northern mollusca. The Newbournian bay 

 was in its turn silted-up by material lithologically identical with 

 that of the Waltonian Beds. To a great extent the beach- or shoal- 

 deposits of this period grew also from north-north-east to south- 

 south-west, 1 the small outliers of Coralline Crag at Sutton and 

 Ramsholt, and the main mass of that formation from Gedgrave 

 to Aldeburgh, forming at that time rocky islands in the sea. 



Disturbance again ensued, but caused a subsidence towards the 

 east, so that a part of the Crag sea shrank into a narrow inlet, 

 extending from Chillesford to Bawdsey, bounded on the east by the 

 great bank of Coralline Crag against which the Butleyan deposits 

 rest. This bank was then more or less of the same extent and form 

 as at present, for Red Crag-beds fringe it on the eastern or seaward 

 side also, at Orford and Sudbourn. A small stream may have 

 entered the Butley inlet from the north, as Mr. Alfred Bell dis- 

 covered many years ago at that locality a seam containing land and 

 freshwater shells. 2 This bay was in its turn choked with sediment, 

 much of the lower part of it bedded at a high angle, as if against the 

 edge of a steeply sloping shore or shoal, and in places with a south- 

 south-westerly dip, bat overlain, as at Walton, by Crag horizontally 

 stratified. If the accumulation of sediment in this part of the 

 Crag area commenced from the north, as seems possible, the beds 

 at Bawdsey, in which Carclium grcenlandicum is so abundant, may 

 be the latest of the Bed Crag Series, and more recent than those 

 of Sudbourn or Butley. For a similar reason, the Crag of Felixstowe 

 may be somewhat newer than that of Waldringfield, farther inland: 

 a view which, from the study of the molluscan fauna of these two 

 places, seems to be not improbable. 



The Norwich Crag-beds (I c en i an) are separated by a considerable 

 interval from any part of the Bed Crag. Their molluscan fauna 

 has a much more recent character ; they never exhibit the highly 

 inclined bedding so characteristic of the Red Crag, and they attain 

 a much greater thickness than the latter ; they occupy an entirely 

 different area, and appear to have originated under somewhat 

 different conditions, being possibly the western edge of the great 



i See as to this also many of the sections in Prestwich's paper, Quart. 

 Journ. Geol. Soc. vol. xxvii (1871) pp. 329 et seqq. 



2 Geol. Mag. 1871, p. 452. Such shells occur also at Hollesley, according 

 to Mr. P. F. Kendall. 



Q. J. G. S. No. 224. 3 d 



