470 S. V. WOOD, JTTIT., ON THE NEWER 



occasionally rafted by field-ice and dropped so as to become inter- 

 stratified in it. The rise of the sea-bed at the commencement of 

 the gravel c and Chalky Clay caused much of this brickearth to be 

 washed away by currents, so that channels were eroded through 

 it, and in these the gravel c accumulated, as the Cromer Cliff" so 

 conspicuously exhibits, especially towards its eastern extremity. 

 Thus, though from its identity mainly with the Contorted Drift 

 which overlies the Till along the Cromer coast I have desig- 

 nated it all as 1)3, this brickearth in the western part of fig. I., pro- 

 bably in its lowest part, represents also the Till itself, the break 

 occurring between these beds or between h 3 and h i, from Bacton 

 Cliif in Sheet 68 to the Aide, disappearing in this part of Suffolk, 

 while still further south all gives place to the gravel h\ as presently 

 to be shown. Drift ice carrying portions of the moraine extruded 

 in shallow water or on the shore (as occurs at places in Greenland), 

 and dropping it, has doubtless been the means whereby the bands 

 of chalky clay just referred to have become interstratified in, and 

 patches of it irregularly scattered through the brickearth. This is 

 especially the case with this brickearth from Cromer to Weybourne, 

 where it is also largely made up of streaks of chalk silt. At Blax- 

 hall (in the south-east of Sheet 50, and 3 miles west of the line in 

 fig. I.) it contains marl masses similar to those in the Cromer Cliff. 

 It is clear to me that the ridge of Coralline-Crag rock which had 

 divided the fluvio-marine from the marine area of the Eed Crag, and 

 been overflowed by the waters of the Chillesford Clay, became, from 

 the resistance which its hard mass offered to the denuding waters of 

 the sea again invading this region at the commencement of Stage 

 II., an island in them, or more probably, as it is divided by the Aide, 

 two islands ; and that the soft Chillesford beds which had been 

 spread over this ridge, as well as the uppermost (or Scrohicularid) 

 beds of the Eed Crag which lay up against it or on its flanks, were, 

 save on this ridge and in its immediate vicinity, everywhere else 

 in the north-east of Sheet 48 and south-east of Sheet 50, swept 

 away ; so that the sands h 1 were here laid down on the lower 

 beds of both the marine and fluvio-marine portions of the Eed 

 Crag and bedded around these islands. The remnant of these 

 soft strata thus preserved by contiguity to this rock, and forming 

 a promontory to the southern of these two islands at Chillesford, is 

 traversed by the line of fig. I. at that place, and that also which 

 formed a similar promontory to the other island is traversed by 

 this line at Thorpe by Aldboro'*. A tract of the same beds at 

 Butley, half a mile wide by one and a quarter long, formed a third 

 island, divided from the section by the Butley Creek. Beyond this 

 south-westwards no trace of the Scrohicularia-Ciaig or of the 

 Chillesford beds has been left until we come to the beds capping the 



* After the Plate had been photo-Hthographed I found that by having con- 

 fused the locahty of the section at Snape with that of one in d, to the north- 

 east of it, two miles of country had been omitted from the line of fig. I. This 

 renders the line there tortuous. 



