256 
BEDS IN THE YALLEY OF THE GADE. 
mainly in Chalk covered by clay-with-flints, hut in the lane, from 
Upper Highway towards Abbot’s Langley, bright-coloured loams, 
clearly derived from pre-existing Reading Beds, were exposed. 
Returning to the consideration of the Hunton Bridge and Home 
Park Farm excavations, it will be admitted that they show (1) the 
existence of several beds of peat, or other carbonaceous matter; 
(2) the occurrence of the well-known light-blue clay, evidently 
derived from pre-existing Reading Beds; (3) the presence of 
a strong current, or currents, of underground water, flowing 
through the ballast above the Chalk; and (4) the existence of 
what seems to be an old river-bed, in the position indicated in 
Fig. 27. So far as can be ascertained from an examination of the 
single line of excavations and the contours of the adjacent ground, 
it would appear probable that this old river-bed lies in the direction 
of a small, but well-marked, transverse valley, extending from the 
high ground, on the eastern side of the railway, towards that part 
of the old river-bed which was seen in the excavations. 
The occurrence of the ballast, light-grey clay, and lower part of 
the loam, is easily explicable on the assumption that the drainage 
of the district was much greater than it is now, and that lateral 
feeders ran into the ancient representative of the River Gade. The 
data are insufficient, however, to furnish a simple explanation of 
the way in which the chalk-rubble, 4, Fig. 27, was deposited. 
,o T a. > >4 £ 7 f Feet - 
Fig. 28. —Section at Hunton Bridge. Scale 6 ft. = 1 in. 
