Rev. Dr. Irving — Old River-Valley near Peterborough. 415 



considerable masses of lignite, but apparently no boulders. It appears 

 to be of local origin. Its junction with the Oxford Clay in situ is 

 seen, in open sections on both sides of the channel, while upwards 

 it is mixed up with the fine stratified river-gravel and sand, which 

 (as interglacial or ' subglacial ' ^ deposits) seem by the evidence of 

 well-sections to have filled the pre-glacial valley, as such deposits 

 have filled the pre-glacial valley of the Stort.^ In composition these 

 gravels (so far as examined) agree remarkably with those at Stansted 

 Mountfichet and other places in the upper Stort valley, and like them 

 contain rolled Belemnites, Gryphseas, etc., from the Jurassic rocks. 

 In other respects tlie gravels have also much in common with the 

 high-level stratified gravels of the Trent at Beeston,* where the 

 Jurassic fossils seem to be wanting. In open sections on both sides 

 of the channel these gravels are, in their upper portions, puckered 

 and distorted apparently by frozen masses of gravel of the floating-ice 

 stage of glaciation, agreeing with the facts observed in the upper 

 Stort valley * and in the old Windsor Forest country of the Thames 

 outer valley * in East Berks. 



The facts observed, as recorded in this and previous papers, taken 

 together with the known physiography of the upper Trent basin, 

 seem to suggest inferentially a connexion in late Tertiary times 

 between that and the Thames Yalley by way of the buried channel 

 through the Chalk Range ^ ; the capture of the Trent by the Humber 

 being accounted for by crustal movements and by the glacial damming, 

 of which the 90 feet of Boulder-clay furnishes evidence, as this was 

 observed years ago by Dr. J. J. Harris Teall and myself, when the 

 Midland Railway from Melton Mowbray to Nottingham was in 

 process of construction. The River Nene above Peterborough appears 

 to cut right across the buried channel, indicating the comparative 

 modernity of the present river-system of the "Wash Basin. 

 ***** 



My more recent work during the month of August (availing myself 

 of the local knowledge of Mr. G. Wyman Abbott of Peterborough) 

 has led me to conclude — from observations made in the sand and 

 gravel pits known as Anker's Pit and Rippon's Pit (both close to 

 Peterborough) and in London Brick Company's Pit No. 1 at Old 

 Fletton — that the relations of the ISTene Valley to the ancient buried 

 channel are not so simple as appears at first sight. In the silted-up 

 Nene Valley, however, the succession of the deposits is roughly as 

 follows : — '' 



1 N. 0. Hoist. ' A. Irving, B.A. Eeports for 1910, 1911. 



* A. Irving, P.G.A., vol. xv, p. 232, 1898. 



* Op. cit., vol. XV, pp. 224, 225. Also Report of Excursion to Bishop's 

 Stortford (1911) : op. cit., vol. xxii, pp. 264 ff. 



^ Op. cit. : Excursion to Wokingham and Wellington College in 1890, with 

 photograph of one of the sections, now obliterated and overgrown. Similar 

 photographs presented at the time to this Association, and one was published 

 in Science Gossip. 



^ See B.A. Report, 1910 (Section C), p. 616. 



■^ [Pre-glacial valleys in Northamptonshire have been described by Mr. Beeby 

 Thompson, Journ. Northants Nat. Hist. Soc, ix, p. 47, 1896, and xii, p. 207, 

 1904.— Ed.] 



