Fisher — Denudations of Norfolk, 547 



section appended to his father's paper, that the Forest bed, and gravel containing 

 fluviatile shells and mammalian remains, are probably the equivalent of the beds of 

 his section from d^ to/ Now the beds thus indicated include the Red and Norwich 

 Crag, the Chillesford clay, and what Mr. Wood calls the Bure valley beds, which 

 are a part of Mr. Gunn's "Lammated" series, or 3^ of Sir Charles Lyell's section 

 in " The Antiquity of Man." In other words he looks upon these deposits as a ter- 

 restrial equivalent of the above marine series. 



Mr. Gunn, whose opinion on all points connected with the geology of the county 

 is of great weight, read a paper before the Norwich Geological Society in 

 November last, from which it appears that he considers the bed of flints with 

 bones of mastodon, lying upon the Chalk, to be alone worthy of the name of 

 Mammaliferous Crag, and that he entirely dissociates from it, in respect of age, the 

 shelly sands which at Thorpe and elsewhere cover it. He would intercalate the 

 Forest bed in time between this bed of flints and the shelly white crag sand, and 

 continue the sequence upwards with the Chillesford clay, and next the Laminated 

 fluvio-marine series, or 3^ of Sir Charles Lyell's "Antiquity of Man." 



Mr. Prestwich during the discussion upon his second paper on the Crag, read 

 at the Geological Society in May, mentioned that he had found what he con- 

 sidered traces of the Forest bed in Eastern Bavent Cliff, above the Chillesford 

 clay, and as he thought indications of the same sequence in the upper part of the 

 cliff at Walton-on-the-Naze. Here then are three distinct opinions put forward 

 by three geologists, more competent, perhaps, than any others on this question. 

 For my own part I lean to Mr. Prestwich's view, and chiefly for this reason. 



During the Crag period we have two proboscideans abundant— the Mastodon 

 Arveniensis and the Elephas nieridionalis. As Mr. Gunn informs us,^ the masto- 

 don and that species of elephant occur together in both the Red and Norwich 

 Crags, but in the Red Crag the mastodon is more abundant than the elephant, 

 while in the Norwich bed their proportions are nearly equal. The Elephas nieri- 

 dionalis is continued into the Forest bed, but the mastodon disappears, other 

 species of elephant coming in to make up the tale. If, then, the mastodon occurs 

 in the Chillesford clay, and the associated upper Crag or Mya bed, that seems to 

 me to afford a strong presumption that the Chillesford clay is older than the Forest 

 bed. Now there are two instances of well-authenticated finding of the mastodon 

 in the cliff at Easton Bavent. One was the tooth of a young animal, which was 

 dug out by Mr. Ewen, of Southwold, from the Upper Norwich Crag, or J/j/« bed. 

 I have seen this specimen, and have a letter from Mr. Ewen in my possession 

 describing li?, giseuient. The other was a portion of a jaw, with a tooth in it, the 

 finding of which, half way up Easton cliff in a fallen mass, is described in a letter 

 from Colonel Alexander to Mr. Wood, of which, by that gentleman's kindness, I 

 possess a copy. It must be understood that this was not the tooth picked up near 

 Sizewell Gap, which is figured in Owen's "Fossil Mammals" as from Colonel Alex- 

 ander's collection. The specimen alluded to fell to pieces. It is perfectly true, as 

 Mr. Gunn has pointed out to me, that a bed of clay, extremely like the Chillesford 

 clay, occurs at the base of the Norfolk cliffs in the lower part of the Laminated 

 series, but I do not think that lithological character is a reliable guide in the 

 present case. A bed of clay in that position could hardly fail to have the Chilles- 

 ford character, but I have seen nothing there at all similar to the Chillesford fossils. 



There is another supposition, which appears to me -worthy of investigation, and 

 that is whether the Chillesford clay may not be a continuation of the lower portion 

 of the soil of the Forest bed. The occurrence of whales' bones in the clay at 

 Chillesford, and also in the soil of the Forest bed, is a remarkable feature of 

 resemblance, and this supposition would intercalate the Chillesford clay in what 

 appears to me to be its most probable position, intermediate between the Crag and 

 the Forest bed. 



At any rate the sequence of events introduced the deposition upon the Crag of a 

 fine clay, most probably formed in an estuary open to the Northern Ocean. To 

 this estuary whales had access, and there is much reason for supposing that it was 

 no other than the estuary of the Rhine, and of the Thames, and other rivers which 

 formed tributaries to it. 



The sides of this estuary next became dry land, so as to allow ctf the growth of 



Norwich Merciiry, Nov. 9, 1867. 



