201 THE PLEISTOCENE DEPOSITS ABOUND CAHBEIDGE. [vol. lxxv, 



11. The Pleistocene Deposits around Cambeidge. By John 

 Edwabd Maee, Sc.D., F.R.S., V.P.G.S., Woodwardian Pro- 

 fessor of Geology in the University of Cambridge. (Read 

 November 19th, 1919.) 



[Plate XI — Sections.] 



I. Inteoduction. 



Since the year 1910 I have devoted considerable attention to the 

 Pleistocene Deposits of the Cambridge district, and believe that 

 my observations will be useful as an aid to future students of these 

 accumulations. 



In a paper read before the Cambridge Philosophical Society in 

 1917, 1 I gave a brief account of the conclusions which I had reached, 

 and noted the importance of a study of the Pleistocene deposits of 

 the Great Ouse Basin, 



'for in this area we get evidence of the relationship of the Palaeolithic 

 deposits to those which were formed during a period of submergence and re- 

 emergence, and also to accumulations which give evidence of the occurrence 

 of more than one cold period.' 



In the present paper I propose to confine myself to a consideration 

 of the deposits in the immediate neighbourhood of Cambridge, with 

 special reference to the sequence of the various members of the 

 Pleistocene accumulations as there displayed (see fig. 1, p. 205). 



In the previous literature devoted to this subject undue stress 

 has been laid upon relative elevation above present river-level. Of 

 recent years it has been recognized that, owing to alternate erosion 

 and aggradation, difference of level must be treated cautiously, for 

 reasons which I gave in the paper to which I have referred. The 

 researches of palaeontologists have enabled us to construct a time- 

 scale based upon fossil evidence (including that furnished by 

 human implements), and I have relied largely upon this evidence 

 in attempting to determine the time-sequence of our local deposits. 

 In doing this, the collections made in past years have been of con- 

 siderable value ; but, as many of the localities from which speci- 

 mens were obtained are only vaguely given, with the result that 

 specimens from different horizons are recorded as coeval, I have, 

 with the aid of many students and others, done a large amount 

 of careful collecting, in order to find out exactly what fossils are 

 associated together. The result is that I am led to modify to a 

 considerable extent the classification of the deposits as made by 

 earlier writers. 



The most important work previously done in connexion with the 

 deposits under consideration will be found recorded in the Geo- 

 logical Survey Memoir, 'The Geology of the Neighbourhood of 



1 Proc. Camb. Phil. Soc. vol. xix (1917) p. 64. 



