﻿298 J. S. Blake — Age of the Kessingland Root-bed. 



II. — On the Age of the Mammalian Eootlet-bed at Kessing- 

 land.^ 

 By J. H. Blake, F.G.S., Assoc. Inst. C.E. ; 

 Of H. M. Geological Survey of England and Wales. 



IN two papers, by Messrs. S. V. Wood, jun., and F. W. Harmer, 

 recently read before the Geological Society, — alluded to by Mr. 

 Belt, in the Geological Magazine for April last, — this Eootlet-bed 

 at Kessingland has been referred to, and described as an interglacial 

 shallow valley deposit ; of an age posterior to the Contorted Drift 

 or Lower Boulder-clay, lying in a trough excavated out of the 

 Chillesford Clay. To make their description more intelligible, the 

 authors (Messrs. Wood and Harmer) subjoin a sketch-map — in their 

 combined paper *' Observations on the Later Tertiary Geology of 

 Bast Anglia," read November 8th, 1876 — and indicate by a broken 

 line the connexion of this trough with the existing (!) valley systems 

 of the rivers Waveney and Yare — which are here mainly cut out 

 of the Chalky Boulder-clay and Middle Glacial Sands — thus ap- 

 parently assuming that, before the Middle Glacial Sands and Chalky 

 Boulder-clay were deposited, there were valley sj^stems occupying 

 much the same positions in this immediate locality as there are now, 

 with the addition of the supposed continuation of the interglacial 

 valley of the Waveney in a south-easterly direction to Pakefield and 

 Kessingland. To strengthen their argument, they likewise give an 

 hjpothetical section ; representing, what they believe to be the true, 

 though concealed, structure of this Waveney valley. They conclude 

 this portion of their paper by stating, " If these views (as pro- 

 pounded by them) are right, there seems reason for suspecting that 

 this Kessingland-bed, containing Mammalian remains and rootlets 

 (which is directly overlain by the Middle Glacial), may belong to 

 the period of interglacial valley excavation we have been discussing " 

 — that is, posterior to the Contorted Drift or Lower Boulder-clay. 



1 will now refer to Mr. Harmer's paper " On the Kessingland 

 Cliff-section," etc., read November 8th, 1876. After criticizing, 

 generally, Mr. Gunn's paper " On the Presence of the Forest-bed 

 Series at Kessingland and Pakefield," etc., read November 17th, 

 1875; and expounding his own views as to the sequence of the beds, 

 etc. ; Mr. Harmer states, " While, however, the posteriority of these 

 Mammaliferous and fresh- water deposits (Eootlet-bed, etc.) to the 

 Crag (Chillesford Clay) seems thus apparent,^ their age relatively to 

 the beds newer than the Crag is obscure, since there is nothing to 

 shoio lohether they preceded the Lower Glacial beds, which are absent 

 from the Kessingland section, or succeeded them — a point of con- 



^ This paper is published by permission of the Director- General of the Geological 

 Survey. 



2 The section of the Kessingland Cliff given (in the Quart. Journ. Geol. Society, 

 vol. xxxiii. p. 137) to show this — besides being inaccurate, together with the 

 description of it, in some important particulars — is very deceptive in appearance, 

 owing to the distorted scale to Avhich it is drawn (the vertical scale being about 13 

 times that of the horizontal), and also on account of the interval between Covehithe 

 and Kessingland (a distance of about 2| miles) being abridged. 



