63 



terraces separately, and endeavouring to trace them as far as 

 possible up the tributary valleys southward, westward and east- 

 ward. 



§ a. The highest and oldest terrace to be found in the 

 present valley of the Cam or Granta, near Cambridge, occurs 

 along the low ridge which runs southward from Barnwell at a 

 level of about 45 to 50 feet above the sea. At the northern 

 end of this are the well-known gravel pits of Barnwell Abbey ; 

 these are now nearly exhausted, and no deep sections are 

 exposed, so that I am obliged to quote the following facts 

 from Mr Seeley's account of the pit\ which agree with my own 

 recollections between the years 1871 and 1874. " Examined 

 generally, the gravel is formed of layers which extend pretty 

 continuously round the pit. The lowest bed exhibited is quite 

 a coarse bed with the pebbles mostly rounded. About 2 feet 

 above this is a bed of yellowish brown marl, almost clay, irregu- 

 lar in thickness from a few inches to four feet. At times, 

 cuttings display one or two similar but thinner beds in the 

 upper part of the section. " As the pit was cut back, these thin 

 bands appear to have thickened into a bed of greyish white 

 marl, which is still visible on the west side of the pit and is 

 underlaid by false-bedded sands containing shells. 



"The most important stratum is the marl-bed [i.e. the 

 lower marl), first described by the Rev. P. B. Brodie, see Camh. 

 Phil. Trans, viir. p. 138 (ante p. 13) ; in this are found 

 fragments of plants, seed-vessels of -Chara, and many shells, 

 some fresh-water, others land forms, nearly all now living in 

 Britain.... Here too are found the bones of various mammals, 

 nearly all extinct ; and in the same bed is evidence of man in 

 his work." 



This evidence consists of an incised bone described by 

 Mr Seeley as being apparently part of a rib of an Elephant, the 

 incisions on which he considers to have been the handiwork of 

 Palaeolithic man ^ No flint implements have ever occurred 

 here, though one or two flakes are said to have been found ^ 



1 Quart. Journ. Geol. Soc, Vol. xxii. p. 476. 



^ See Brit. Ass. Rep., 1862, Tra7is. Sec, p. 94. 



3 A fine specimen of the ' ' hache " type has however recently been obtained 

 (1878) by Mr A. J. Griffith from the pit on the other side of the Newmarket 

 road. 



