VALLEY-GEAVELS ABOUT EEADING. 587 



in a line parallel with the direction of the present river, near where 

 the upper gravel thins out on the valley-slope and leaves them near 

 the surface. Further back in the gravel-working they lie under 

 many feet of gravel, but finally disappear. 



It will be seen by reference to the figure, p. 585, that relatively 

 tranquil conditions of deposit supervened, as shown by a sandy seam 

 (between a and b) near the top. Some years ago this was exposed 

 as a very distinct bed of greenish sandy clay with small xjebbles. As 

 it passed over one of the masses of chalky gravel its level was con- 

 siderably raised, as if on account of the latter. A non-ochreous 

 gravel, apparently of more recent date, comes in above (c in the fig.). 



Eestiug on the Tertiary Sand (d) at the base of the gravel are 

 many massive flints and some sarsen-stones. 



Mint implements are sparsely scattered in the gravel, and it is 

 not easy to obtain a specimen in situ ; but, owing to the quantity 

 of gravel removed, a considerable number have been secured. Some 

 of the forms have been described by Dr. Stevens *. Thougb chiefliy 

 found in that part of the gravel which is associated with the in- 

 cluded masses of a chalky gravel, yet they occur in both kinds of 

 gravel (a and b), and some few have been found in the uppermost 

 gravel (c) which covers the greater portion of the sheet. 



As a rule the implements are much worn by attrition, and the 

 appearance of many of them further suggests that they have had 

 continued use. Flakes and fragments with sharp edges are, how- 

 ever, by no means uncommon. The surface-colouring varies. Some 

 of the tools are of black flint, little altered, and these seem to be 

 confined to the chalky gravel (a^). A common tint is a deep 

 ochreous brown. Others are lighter, and some are of a uniform 

 dirty white. In some cases the mineral condition of the surface 

 is sufficiently accounted for by the position of the implements 

 in the present gravel, the matrix in which they are embedded, 

 and their nearness or otherwise to the surface of the ground. 

 There are cases, however, which are not fully explained in 

 this way. It is not unusual in gravels of this kind to find 

 unworked stones, which have apparently come from an older 

 gravel, as they exhibit fractures of two distinct ages. In the 

 chalky gravel some of the implements are of black flint, slightly 

 altered on the surface, while others are more or less ochreous. 

 Cases of this kind are by no means clear or conclusive. One 

 implement, however, had evidently been abraded and had ac- 

 quired its present coloration before it was swept into this gravel 

 deposit. It has been much worn, so that the marks of chipping 

 are almost obliterated. Its surface is an opaque whitish colour, 

 slightly mottled with light brown. It has escaped any serious 

 fracture ; but small pieces have been knocked off its edges, and 

 where that has occurred quite a different patination is apparent 

 which shows the extent to which the surface has been modified in 

 the present gravel. It appears, therefore, that this tool has been 



^ Journ. British Arch^ol. Assoc. 1881. 

 Q. J. G. S. No. 184. 2 u 



