PLIOCENE PERIOD IN ENGLAND. 469 



fication is followed by the main mass of the Till reposing more 

 irregularly upon the uppermost sand layers or pebble bands. 



The extent to which the sand bl covered the Ked-Crag area, as 

 discussed in Stage I., is obscure ; because the yellow stratified sand, 

 marked ? in fig. I., seems to pass down into the red loamy sand 

 which, from its occasionally containing indurated bands with casts 

 of shells, can be recognized as the Eed Crag altered, and to some 

 considerable extent restratified also by the decalcifying agency of 

 rain-water. This yellow sand at the great scarp at Wilford Bridge 

 (shown in fig. I.) overlies an irregular surface of the red loamy sand, 

 and occupies depressions in it, so that but for the bands of stratifica- 

 tion running through both sands in common they would appear as 

 distinct formations. As the decalcifying action has, however, 

 extensively produced apparent restratification by rearranging the 

 soluble ferruginous and argillaceous materials which by their colour 

 give rise to the bands of stratification without changing the position 

 of the insoluble residuum of sand grains, I think that these red and 

 yellow sands, thus apparently stratified as one, are nevertheless 

 distinct formations, and that the upper of them represents the 

 southerly extension of the sand hi as shown in fig. I. ; for the 

 abrupt cessation of the Chillesford beds at Chillesford and Butley, 

 and their overlay at the latter place and at Aldboro' by this sand, 

 seems to me inexplicable otherwise. 



This yellow sand is overlain by and, for aught that is disclosed to 

 the contrary, appears to pass up into the finely stratified brick- 

 earth marked bS in fig. I., which is more than 50 feet thick, and 

 contains chalky silt, chalky grit, and thin bands and patches of 

 chalky clay similar, except in the smallness of the chalk lumps, to 

 that of Stage III., and which in this respect so resembles the Con- 

 torted Drift at Weybourne on the IS'orth-JN'orfolk coast. The rem- 

 nants of this brickearth which have escaped destruction from the 

 denuding action of the sea during the rise of England in Stage 

 III. are in the north-east of Sheet 48 considerable, and they 

 formed shoals and islands during the later part of that Stage as 

 shown in map No. 2 ; for they extend beyond the line of fig. I., 

 another island of this brickearth overlying the yellow sand at 

 Kirton and Trimley, 6 miles to the south-east of the line in that 

 figure. Nowhere, however, do we get any thing beyond wells such 

 as that at Kesgrave, which, after passing through 50 feet of the 

 brickearth (the actual excavations in it having stopped at 40), entered 

 the sand, to show the precise relation which it bears to the sand 

 beneath* ; but every thing points to its being a continuation of that 

 sand by change of sedimentary deposit. The submarine extrusion 

 of moraine to which the Till owes its origin does not appear to have 

 reached so far as this part of Suffolk ; but the clayey and chalky silt 

 which issued from the ice bottom was here thrown down in the form 

 of finely stratified brickearth, and in the place of the sand previously 

 accumulated there ; while the material of the chalky moraine was 



* At Hasketon it appears to contain and be underlain by gravel beds, as 

 does the Contorted Drift shown in fig. XV. and that capping Dunwich Cliff, 



