Vol. 69.] AGE OF THE SUFFOLK VALLEYS. 587 



Suffolk valleys are possibly also of post-Lower Boulder Clay age, 

 but of this there is no direct evidence. At any rate, the Lower 

 Boulder Clay is never found extending down into the valleys, and 

 lying in them. Where it occurs in the north, it is cut through 

 by them. 



The Waveney Valley, bordering Suffolk and Norfolk, will only 

 be considered incidentally, as it has already been dealt with by 

 Mr. Harmer. 



III. Position of the Utpee (Chalky) Bouldek Clay. 



As described above, the Drift deposits of the greater part of 

 Suffolk consist of the Upper (or Great Chalky) Boulder Clay, under- 

 lain by sands and gravels with intercalated loams, classed in the 

 Memoirs of the Geological Survey as ' Middle Glacial.' (As there 

 are no Lower Glacial deposits over nearly the whole county, the 

 name is hardly suitable. It is not at all certain that the beds are 

 equivalent in age to the 'Middle Glacial' of Norfolk, where the 

 Lower Glacial beds do occur.) In each of the main valleys, refer- 

 ence to the 1-inch Geological Survey maps shows that the Upper 

 Boulder Clay transgresses the various outcrops exposed, resting 

 promiscuously on each descending member of the Pliocene or Eocene 

 Series, or even upon the Chalk where that bed reaches the surface. 

 Subsequent mapping on a larger scale (6 inches to the mile) has 

 enabled me to confirm this, the way in which the Boulder Clay 

 wraps over from the plateau into the valleys being highly charac- 

 teristic of that deposit. Sections of beds exposed in the valleys 

 also indicate the same fact; and, in cases too numerous to mention, 

 the Drift ploughs into and overlies the older beds. A few typical 

 sections only in each valley need be mentioned : — 



Waveney Valley. — As pointed out by Mr. F. W. Harmer, the 

 features of this valley are similar to those of the Central Norfolk 

 rivers. The classic sections of Beccles, for example, show Chalky- 

 Kimeridgic Boulder Clay resting on Chillesford Beds down in the 

 valley at about 30 feet O.D. and upon the Contorted Drift, a mile 

 to the south, at about 70 feet O.D. 



Aide Valley. — The Boulder Clay extends down into the 

 Marlesford and Saxmundham tributary valleys, and is seen in 

 pits at Blaxhall, on the banks of the main stream, as a valley- 

 deposit at 50 feet O.D. 



Butley Valley. — The stream occupying this is now really 

 tributary to the Aide ( = Ore) at Orford, and the famous Chillesford- 

 Church pit, at just less than 50 feet O.D., shows the Upper Drift 

 resting on estuarine Chillesford Clay and Sands. 



Deben Valley. — Of numerous sections, that at Wickham 

 Market may be cited, where there was a brickyard in Boulder 

 Clay down in the valley at less than 50 feet O.D. 



Gripping Valley. — This is the most typical of the Suffolk 

 valleys, both on account of its relatively large size and on account 

 of the sequence of strata which it exposes on its sides : that is, a 



