770 - MR. F. W. HARMER ON THE [Nov. 1 896, 



There is no reason to suppose that the Chillesford Clay is a deep- 

 water deposit, but it corresponds very closely with the hypothesis 

 of its estuarine origin . It is composed either of unstratified clay, of 

 a character similar to that of mud produced by inundation, or of fine 

 alternating lamina? of sand and mud, being more clayey and easy to 

 trace in one part of the area, and becoming more sandy, less 

 micaceous, and somewhat more difficult to map in the other. The 

 absence from it of an estuarine fauna has been commented on. 

 It rarely contains shells, however, but when it does they are the 

 shallow-water forms of the Norwich Crag, and of a character not 

 unlike those which may now be found along the banks of the 

 estuaries of Suffolk. The skeleton of a cetacean, 30 feet long, 

 was found at Chillesford, and this may have been brought up by 

 the tide, and stranded at low water. Such an occurrence is by no 

 means infrequent at the present day : Hyperoodon rostratus has 

 been taken in the Thames at Barking and Millwall, and the grampus 

 at Battersea, and in the Humber nearly 40 miles from its mouth. 



The Chillesford Clay may thus indicate an elevation of the Norfolk 

 area, by which the sandy bay or inlet of the Norwich Crag became 

 land, and a muddy tidal estuary, similar to those of the East of 

 England or of Holland at the present day, but on a larger scale, 

 established itself in East Anglia. Mr. Wood and I formerly believed 

 that this estuary opened to the south, but I now think that the con- 

 trary was the case. Mica, which forms the most constant and 

 characteristic feature of these deposits, commonly occurs in the 

 Dutch beds, having been brought down by the Rhine and the Mouse 

 from the Devonian and Carboniferous schists which occur in the 

 region drained by those rivers. Pebbles of white quartz and other 

 rocks similar to those of the Rhenish and Mosean drifts of Holland 

 may be found in the Chillesford Clay, as indeed in all the Pliocene 

 beds of Norfolk. 



Although the sea had at this time retired both from Holland and 

 East Anglia, the Rhine must have continued to discharge into the 

 North Sea, and the estuary of the Chillesford Clay may have formed 

 one of the channels by which it did so. 1 It does not seem im- 

 probable that the Rhine may have been diverted towards the 

 western side of the Pliocene basin, as a slight subsidence of Suffolk 

 took place at this period, and carried the Chillesford Beds over a 

 district which was dry land during the deposition of the Norwich 

 Crag. 



I have shown in the map (PI. XXXIV.) the possible connexion 

 between the Rhine and East Anglia, but it will be further seen 

 that, if all the exposures of these beds which are recognized as such 

 by the officers of the Survey and myself be taken, they arrange 

 themselves in a sinuous line from Walton-on-the-Naze in Essex to 

 Mundesley on the Cromer coast. I do not wish to press the point 

 too far, but I think that this can hardly be accidental, and that it 



1 In every case where the Bhine is mentioned, it is understood to include 

 the affluents of that river, and especially the Meuse, from which much of the 

 Southern Drift of Holland seems to have been derived. 



