Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/138

100 100 3. V. WOOD, JUN., AND F. W. HAKMER. ON THE Fig. 19. — Hypothetical Section (XIX.) showing the general Structure of the Waveney Valley. (Vertical scale 17| times the horizontal.) 1. Formations older than the Contorted Drift. 6. The Contorted Drift. 7. The Middle Glacial, including therein any valley-bed of interglacial age that may be concealed under the alluvium &c. 8. Upper Glacial. 9. Gravels posterior to No. 8. 10. Postglacial valley-gravel and recent alluvium. It seems to us that the high ground of Central as well as much of that of East Suffolk is underlain by the Contorted Drift ; but, with the exception of a very few exposures, this is concealed everywhere by the Upper Glacial, while the Middle Glacial intervenes in the same irregular way in which it occurs over the Contorted Drift in that part of Northern Norfolk to which the Upper Glacial does not extend. It is our view that into the troughs or valleys which were inter- glacially excavated in the Lower Glacial and Crag and other older beds, the Upper and Middle Glacial were bedded so as to obliterate those troughs more or less. Most of the troughs thus filled in have been re-excavated postglacially, so as to form the present lines of drainage ; but others have not ; and among them is the supposed south-easterly continuation of the Waveney valley to which we have already adverted. The map which accompanies our " In- troduction " shows that the Lower Glacial beds crop out con- tinuously * along both sides of the Yare valley below Norwich down to its inosculation with that of the Waveney, where this bends to the north-west and where section no. XVI. is taken, as they do also along the northern side of the rest of the Waveney valley for some distance in the direction of Beccles. On both sides of the river at and near Beccles the Chillesford beds and Lower Glacial sands are present ; but between Beccles and Lowestoft we could find no trace of either on the south side of the Waveney t, and the Middle Glacial overlain by the Upper Glacial seems to stretch along the valley-side from Beccles to near Lowes- toft. Now it is through this part, south-eastward to the coast at Kessingland, that we consider the inosculated interglacial trough of to, owing to the concealment, in places, of the Lower by the Middle Glacial on the valley-sides ; but this could not well be represented on the small scale of the map. t Except, possibly, the bed mentioned at page 96 as occurring at the bottom of the cutting of the Lowestoft branch Railway.
 * This continuity is doubtless less than represented in the map referred