86 S. Y. WOOD, JTTN., AND F. W. HARMER ON THE 



23rd vol. of the Journal, because, although the succession of all 

 the beds out of which the valley is cut are correctly represented in 

 them the sweeping-down of the Middle Glacial over the edges of the 

 Lower Glacial and Crag, such as is shown in section V. of the present 

 paper, is not introduced, we not having then discovered it. The 

 figure (no. 1) given in the 23rd vol. (p. 88) of the bed at Trowse 

 shows that the clay there is partially overlain by brickearth and 

 sand, much in the same way that the bed in the Blackwater valley 

 (section XXIII. of the present paper, p. Ill) is overlain. The sand 

 over the brick-earth at Trowse, and the gravel over the brick-earth at 

 Appleford bridge in the Blackwater valley, seem in both instances to 

 show the transition upwards of this interglacial valley-bed into the 

 Middle Glacial. The Middle Glacial sand overlain by the Upper 

 Glacial of the pit at Tuck's- Wood farm on the hill above the Trowse 

 section indicates, we now think, part of the infilling of the Yare 

 valley which had been denuded interglacially out of the Lower Glacial 

 and Crag beds and the Chalk ; and fig. 6 represents what we think 

 the relative position of the several beds is most likely to be. 



Fig. 6. — Section VI., at TucVs-Woocl Farm. (Length 2 miles. 

 Vertical scale 17| times the horizontal.) 



N. Cutting at Pit at Pit at S. 



Victoria Tuck's-Wood Trowse River 



Station. Farm. Junction. Yare. 



A /4 r 



1, V, 4, 5, 6, 7, and 8 as in fig. 5. 



a. Bed of clay chiefly made up of chalk debris and partly overlain by thin 



Brick-earth and by sand. 

 10. Postglacial valley-gravel and recent alluvium. 



The dotted line indicates the supposed continuation of the interglacial valley 

 beneath the recent alluvium. 



Pursuing now the valley of the Wensum, the following three 

 small lines of section (Nos. VII., VIII., and IX.) are necessary to 

 illustrate its interglacial excavation, as we are not able to give a 

 line across both sides of the valley at any one point which can be 

 sufficiently verified by open excavations, abundant even as these are 

 over the country traversed by this valley. 



The lines of these sections are taken at distances (following the 

 sinuosities of the valley) of 20, 29, and 39 miles respectively above 

 Norwich, section VII. being the lowest, and IX. the highest up the 

 valley. 



It often happens towards the upper end of the valley that the 

 Upper Glacial rests direct on the Contorted Drift ; and some good sec- 

 tions of the two in contact occur near Guist in the Wensum valley ; 





