OBSERVATIONS. 21 



at Kesgrave, is shown in the map, but another occurs at California-by-Ipsvvicb, another at 

 Kirton, and another at Rookery Farm, Eyke, none of which are shown in it. All of 

 these appear to be of considerable thickness (40 to 50 feet), and the first and last of 

 them have a little of the Middle Glacial gravel over them in places. Another patch, on 

 the Hasketon side of Woodbridge, is overlain by the chalky clay ; and at Tuddenham, 

 near Ipswich, the base of this brickearth is exposed passing down into the sand No. 6, 

 of which about twenty feet underlies it, and rests on the London Clay ; and there also 

 the denudation of this brickearth, which took place prior to the deposit on it of the 

 Middle Glacial gravel, is well shown by the irregular way in which that gravel lies 

 upon it. Remnants occur also in other parts of South SufiPolk, but they are beyond 

 the limit of the map.^ In the Section (a) drawn through the Red Crag area, the 

 Middle Glacial is therefore erroneously represented as resting generally on the Red 

 Crag, whereas this is exceptional, and the Lower Glacial sands should have been shown 

 in most parts {i.e. in those where they have not taken the place of the Crag altogether) 

 as intervening, and the thickness of the Middle Glacial been there proportionately 

 reduced. The correct position of all the beds of this sequence is shown in fig. 1 of 

 the plate which accompanies my memoir on the " Newer Pliocene Period in England," 

 in the thirty-sixth volume of the ' Quarterly Journal of the Geological Society,' the line 

 of which is drawn through three of these remnants of the brickearth ; and in it the 

 Middle Glacial gravel is shown on the plateaux as very thin, and in places absent 

 altogether, but as thickening towards the brows of the valleys, which, when they were in 

 the condition of troughs excavated in the rising sea bottom of the sand No. 6, had 

 been filled by it ; the gravel in the central parts of these troughs having been cut out as 

 these were deepened by the shrinkage into them of the ice of the chalky clay, or by the 

 action of the sea, as emergence went on. A well which I sunk to a depth of eighty-four 

 feet subsequently to the publication of that figure, but on the exact line of it, and on the 

 eastern edge of the plateau from which the valley of the Deben is cut down, showed 

 this gravel to be there seventy feet thick beneath six feet of the chalky clay (the upper 

 thirty feet being full of the chalk debris of that clay), and that the sands No. 6 had been 

 almost all removed to give place for it. It is this sand, or else that formed by the 

 decalcification of the Crag, and not the Middle Glacial, which overlies the Crag shown iu 

 the cut on page xxi of the " Introduction " and in Sections XIX and XX. 



The map thus requires to be corrected by the intercalation of a belt of the shade and 

 colour representing the sand No. 6 between the Red Crag and the Middle Glacial ; and it 



1 One of these, at Stowmarket, is in the footnote to p. 22 of the " Introduction," referred to as of 

 post-glacial age, and another about six miles north of Ipswich, and three-quarters of a mile south-west of 

 Hemingstone Church, is shown in the map by a dot of the wrong colour (that of bed No. 10). I am 

 informed also by Mr. Dalton, of the Geological Survey, that he found an exposure of this brickearth under 

 the chalky clay at Baddingham, just midway between the patch of it shown in the map at Bloxliall, in 

 South-east Suffolk, and the exposure of it at Withersdale, on the Waveney, near Harleston, sc^ that pro- 

 bably much of the chalky clay of High Suffolk is underlain by remnants of the same bed. 



