470 PBOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Conclusion. 



Nothing can be clearer than the relation of the Eed to the Coral- 

 line Crag ; but the Norwich Crag occupying a different area, and each 

 area presenting a crag-series of its own type, without superposition 

 or passage, their relation to one another must necessarily be esta- 

 blished on other grounds. We have to see what other beds there 

 may be common to the two districts, whether in each they bear 

 a like relation to those Crag beds which are the object of inquiry, 

 and whether the differences known to exist in the latter may not be 

 owing to geographical distribution. 



In this case we have the one common bed in the Chillesford Clay, 

 which forms a zone limiting in ascending order the position both of 

 the Red and of the Norwich Crags, both of which it overlies and 

 with both of which it shows a close relation. But although we can 

 follow the Chillesford Clay (retaining its usual characters and fossils) 

 into the southern part of the Norwich-Crag area at Southwold, north 

 of that district it is not fossiliferous and we can only identify it by 

 position and mineral characters. Nevertheless we can follow this 

 argillaceous zone, although a character of uncertain value, with 

 sufficient clearness to Bacton and Weybourne, and also inland to 

 Norwich and Coltishall. In Norfolk, however, as the sands and 

 shingle overlying the Chillesford Clay become interstratified with 

 beds of laminated clay very similar in appearance to the Chillesford 

 Clay, it might be a question whether the bed which I have referred 

 to that deposit in Norfolk belongs to it, or whether the Chillesford 

 Clay is represented by the Laminated Clays of Mr. Gunn. Mr. Gunn 

 contends that such is the case. Although I am ready to admit that, 

 on lithological characters alone, the evidence would be almost as good 

 for one as for the other, still I think that the clear superposition of 

 the Chillesford Clay to the Crag, and its infraposition to the West- 

 leton shingle, at Easton Bavent, with the commencing indications of 

 the Forest-bed at the same place, and its clearer exhibition at Kes- 

 singland, accompanied by the setting in, in the same cliff, of the 

 Elephant-bed — taken in conjunction with the presence of the Mas- 

 todon in the Norwich Crag and its absence in the Forest-bed, and the 

 difference in the species of Elephant, Rhinoceros, Deer, cfec. in the two 

 series — sufficiently prove their relative position and age. Mr. Gunn's 

 Laminated Clays constitute a subordinate lithological character of 

 the Westleton series in Norfolk, and are occasionally present in 

 Suffolk. 



The Forest-bed, of which we get indications at Easton Bavent, is 

 more fully developed at Kessingland and Corton, at which latter 

 place it passes under the lower division of the Boulder-clay, the 

 "Westleton shingle having been denuded as it occasionally has been 

 even in the Hasborough and Mundesley district (see fig. 36, p. 465). 

 At Hasborough and Bacton the base of the Westleton shingle 

 is usually cemented into a hard " pan " by oxide of iron, and 

 constitutes the well-known Elephant-bed. This reposes upon the 

 Forest-bed, which, in its turn, rests on the ChiUesford Clay when 



