Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/571

 445 PROCEEDINGS OF THE GEOLOGICAL SOCIETY.

POSTPONED PAPERS.

1. On a Peculiar Instance of Intraglacial Erosion near Norwich. By Searles V. Wood, Junr., Esq., F.G.S., and F. W. Harmer, Esq., F.G.S.

(Read April 14, 1869*.)

The object of the present brief notice is to bring before the Society, while the works are in progress, a feature of intraglacial structure disclosed by the sewerage works at Norwich, in order that, since the case appears to us to be peculiar among the perplexing features presented by the glacial beds as far as yet known, the opportunity may be afforded, to any who may suspect that some mistake has been made, of investigating the accuracy of our representation before the means of doing so are removed. For this reason we have ventured to bring the subject forward now, instead of reserving it for description with the general glacial structure of the east of England, which we hope at some future time to lay before the Society.

All the valleys of Suffolk, and of Central and Eastern Norfolk, are excavated out of the glacial beds, and possess no connexion whatever with any preglacial condition of the surface. They appear, however, to have had their configuration and direction determined in several places by a denudation of the glacial beds themselves, which was effected during the progress of their deposit. Of this the case before us affords one instance.

The accompanying section shows the structure of the valley of the Yare, near the places of its inosculation with that of the Tese and that of the Wensum. The sewer-works, up to the present time, have been carried on by shafts, sunk in the bottom of the valley, where the surface is considerably below the line maintained by the chalk on either of its sides. These shafts have disclosed that a hole or, it may be, a narrow trough in this part descends abruptly, and almost perpendicularly, into the chalk, and that in it Hes, not merely one of the successive beds (5) which form the solid mass of the country around, but also another bed which does not appear to exist elsewhere in the neigh-


 * For the Discussion on this paper, see p. 260 of the present volume.

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