GEOLOGY view, although recently opposed by Mr. Harmer, accords with the general evidence along the East Anglian coast of successively newer stages as we proceed from south to north. In the Norwich Crag we have a series of shelly sands, orange- coloured and white pebbly sands and gravels, and thin seams and extensive 'jambs' of laminated clay, to the more persistent masses of which the name Chillesford Clay has been applied. It is indeed a great series compared with the Coralline and Red Crags, for it has been found to attain a thickness of nearly 200 feet in places, the thick- ness increasing from the outcrop,' probably to some extent owing to erosion of the strata during the Pleistocene period. In 1849 Prestwich described the sections at Chillesford near Orford where the Red Crag with Scrobkularia is exposed in a stackyard, over- lain by buff shelly sand and a band of loamy clay, to which the name Chillesford Clay has since been applied.^ This clay occurs over some extent of ground near Chillesford and at Iken. Somewhat disturbed and rearranged beds of the clay overlie the Norwich Crag at Dunwich ; it is not seen at Southwold, but thinner layers representing it occur in the shelly sand and pebbly gravel at Easton Bavent. It occurs also at Cove- hithe and Kessingland, at Beccles, near Herringfleet, Somerleyton and Blundeston. It is not to be regarded as the highest portion of the Norwich Crag Series, for in Norfolk it is represented only here and there sometimes overlain by shelly gravel, and elsewhere apparently replaced by the highest stage of the Norwich Crag, known as the Weybourn Crag and Bure Valley Beds. Here we enter the region of controversy, and it will be sufficient to mention that this highest group is succeeded in Norfolk by the Forest Bed Series, which is represented in places on the Suffolk coast. Following Mr. Harmer we may regard the Norwich Crag as extending from the neighbourhood of Thorpe or Aldringham Common near Aldeburgh to Dunwich, Southwold, Bulchamp and Wangford, and to the Waveney valley near Bungay and Beccles. These include the most famous localities for fossils, but in many parts of Suffolk, as in Norfolk, we find few or no fossils, as in the Minsmere valley at Darsham and Y oxford, and in the Blyth valley at Thorington, Halesworth and Walpole. In some cases no doubt the shells have been dissolved away. Thicknesses of 105 feet at Saxmund- ham, 133 at Leiston, 147 feet at Southwold and 80 feet at Beccles have been assigned from the evidence of well borings to the Norwich Crag, without including certain pebbly gravels which at any rate at Southwold and Beccles most likely belong to the series.^
- See Whitaker, G«/. Mag. (1895), p. 464; Harmer, ^art. Joum. Geol. Soc. Hi. 767; Pm.
Geol. Assoc, xvii. 443. ^ Sluart. Joum. Geol. Soc. v. 345 ; xxvii. 336, 337. See also Harmer, ibid. liv. 309 ; Ivi. 708, 721 ; and Reid, ' Pliocene Deposits of Britain,' p. 100. ^ Reid, ' Pliocene Deposits of Britain,' p. 201 ; and H. B. Woodward, 'Geology of the country around Norwich,' Geo/. Survey (1881), p. 31. See also Prestwich, ^art. Joum. Geol. Soc. xxvii. 343, 3H- 15
