1865.] FISHER CHILLESFOED BEDS. 19 



of selenite with that of the organisms to whose former existence it 

 owed its origin. It is clear that if organisms deposited in sediment 

 contribute at the commencement to the formation of such minerals 

 as selenite, which are removeable in their turn, after a while the 

 sediment may become free from all trace of former organic matters. 

 In other words, there is no reason why the purest clay-slate may not 

 have been formed from a fossiliferous clay. 



2. On the Relation of the Norwich or Eluvio-maeine Crag to the 

 Chillesford Clay or Loam. By the Rev. 0. Pisher, M.A., 

 P.G.S. 



During the month of August last, in company with Professor 

 Liveing, I visited Orford and Aldborough, and we made some obser- 

 vations which may tend to clear up the uncertainty which hangs 

 over the relations of the Red Crag, Chillesford beds, and Fluvio- 

 marine or Norwich Crag. We took with us the paper by Mr. Prest- 

 wich on the Chillesford Beds, in vol. v. of the Society's Journal, 

 that by Mr. S. Y. Wood, jun., " On the Red Crag and its Relation to 

 the Pluvio-marine Crag, and on the Drift of the Eastern Counties!" 

 (Annals and Mag. of Nat. Hist., March 1864), and the same author's 

 " Map of the Upper Tertiaries of the Eastern Counties, with remarks 

 thereon," privately printed, 1865. After having begun to digest 

 the materials we had collected, I visited the same neighbourhood 

 again in the beginning of September. 



Mr. Prestwich has left it open as to "whether the Chillesford 

 deposit may not be identical with the Mammaliferous Crag of Nor- 

 wich"*, or whether it "may not belong to a period one stage more 

 recent than the Mammaliferous Crag ; whether in fact it may not be 

 the marine representative of that thin marine, freshwater, and land 

 series, which, on the north-eastern coast of Norfolk, is spread over 

 the patches of the Norwich Crag, and immediately underlies the great 

 northern clay drift," i, e., I conclude, Mr. Gunn's " laminated beds." 

 Sir Charles Lyell, however, in his work on the Antiquity of Man, 

 decidedly adopts the former view, saying that " the most southern 

 point to which the marine beds of the Norwich Crag have been 

 traced is Chillesford, near Woodbridge in Suffolk "f. 



Mr. Wood, jun., on the other hand, considers the Chillesford beds 

 to be a local member of the division of the glacial series, which in his 

 last-mentioned paper he terms " the middle drift." He says, p. 4, 

 " The Chillesford beds described by Mr. Prestwich in 1849 as over- 

 lying the Red and Coralline Crags, pass up without the least break 

 into the middle drift, and are evidently part of that division." And 

 with respect to the Eluvio-marine Crag and its relation to the Chil- 

 lesford beds, he says, " The conclusion I have formed is that the 

 Eluvio-marine Crag of Thorpe is inferior to the fifth stage Red Crag" 

 (that is, the phosphatic nodule bed), while in another place he states 



^ Quart. Journ. Geol. Soc. vol. v. p. 351. f Ed. 1863, p. 211. 



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