Or THE UPPER CRETACEOUS IN" WEST SUFFOLK A3TD NORFOLK. 547 



Now it is remarkable that these phenomena are similar to those 

 found near the southern termination of the Cambridge Greensand 

 in Bedfordshire; the phosphates dug near Barton in that county 

 exhibited a similar preponderance of light- coloured nodules, and it 

 was specially observed * that their surfaces were fresher and less 

 water- worn than those of the Cambridge nodules. It was shown, 

 in the paper referred to, that these nodules were in all probability 

 derived from the uppermost beds of the Gault, and the resemblances 

 between them and the nodules from the Beach and Soham pits are 

 therefore very suggestive ; this point will be again referred to in the 

 sequel. 



The most northern locality where the Cambridge seam has been 

 worked is near Wedd's Farm, about two miles north-east of Soham, 

 where it was not far from the surface. Beyond this spot its course 

 is unknown, and no line for the base of the Chalk beneath the 

 Fenland has been drawn on the Geological Survey map (sheet 51, 

 N.E.) ; there can be little doubt, however, that it runs below 

 Mildenhall Fen, and probably passes out of sheet 51 into sheet 65, 

 about a mile and a half north-west of Lakenheath. How far the 

 nodule-bed continues at the base of the Chalk-marl is of course a 

 matter which could only be decided by making a series of borings 

 through the fen-beds along the line above indicated. 



Gault is said to underlie the gravel of Shrubb Hill, which is 

 an island in Hockwold Fen, on the north side of the Little Ouse, 

 but the base of the Chalk-marl seems to be still below the Fen- 

 level. 



Between West Dereham and Stoke Ferry the Gault once more 

 rises above the level of the Fen, and forms a low-lying plain be- 

 tween the ridges of the Lower Greensand to the westward and the 

 slope of the Lower Chalk on the east. 



That this is really Gault we have not the slightest doubt. ILr. 

 C. B. Rose, who was the first to describe it, seems at first to have 

 had some doubt whether it was true Gault ; but his hesitation was 

 set at rest by "William Smith, who identified it by the fossils he had 

 found in itf, so that we find Fitton (in 1836) accepting its existence 

 as an established fact. Mr. Rose afterwards succeeded in tracing 

 the several detached exposures of this clay from West Dereham to 

 Congham and West Newton, and records the finding of other Gault 

 species From this time, no doubt was ever thrown on the occur- 

 rence of Gault in West Norfolk until 1885, when Messrs. Reid and 

 Sharman § raised the question in the 1 Geological Magazine,' and sug- 

 gested that the whole of it was Chalk-marl, asserting that it con- 

 tained a Chalk-marl fauna. 



From their conclusions we entirely dissent, and our reasons for 

 maintaining that this clay is really Gault have already been 

 published, so that we need not repeat them here ; but we think that 



* See Quart. Journ. Geol. Soc. vol. xxxi. p. 262. 

 t Phil. Mag. vol. vii. (1835) p. 179 et seg. 

 X Proc. G-eol. Assoc. vol. i. p. 234. 

 § Geol. Mag. dec. hi. vol. iii. p. 55. 



