PRESTWICH BEIGHTON BEACH. 



217 



Avisford and trends away northward to the Chalk Downs, we find 

 the subangular flint-gravel overlying the same bed of sand, with 

 the mottled clays cropping out from beneath. PoUowing the dell 

 northward for a distance of five furlongs from the high-road, I found, 

 on its west slope, a sand-pit (fig. 1) which afforded a far better section 

 than I had hitherto met with. 



The base of the sand is not seen in this pit ; but the chalk crops 

 out at a short distance, and at a level not many feet lower. The 

 sand is light-coloured, siliceous, and roughly bedded, and contains a 

 few thin seams of fine, worn shingle and a few dispersed rolled and 

 worn flints — also traces of carbonaceous matter, but without a trace 

 of any shells that I could discover. On the top of this sand is a bed, c, 

 3 to 4 feet thick, consisting of closely- compacted flint-pebbles chiefly 

 of one size — about that of an egg. Although well worn, they are, 

 unlike the smooth and regular Tertiary pebbles, only roughly rounded 

 ■^ust such as we should now find on an exposed shore. The inter- 

 stices between the flints are filled by clay like that of the drift 

 above, and seemingly without any fossils. Irregularly spread on 

 the old shingle is a dark ferruginous clay-drift, a, full of large 

 and small, sharply angular, and unworn flints, with, here an'd 

 there, a worn pebble caught up from the shingle beneath. But the 

 important feature of this section is the height to which this old sea- 

 bed here rises above the present sea-level, and the fact of its inter- 

 section by one of the existing system of vaUeys. By observation with 

 an aneroid barometer, I should estimate its height above the sea 

 to be about 80 to 100 feet. The dell, near the brow of which it is 

 situated, commences on the higher part of the Downs, where it is 

 known as the Fair Mile Bottom, passes by Dale Park and Avisford, 

 and joins, at Binsted, the great flat plain of the coast. The gravel 

 and sand are found on both sides of the dell for a distance of about 

 three-quarters of a mile above Avisford, ending at a short distance 

 from the above sand-pit. (See fig. 2.) 



w. 



Fig. 2. — General Section across Avisford Dell. 



Slindon Common. Sandpit. Wooded Dell. 



Arundel Woods. 



a. Angular flint-drift, passing into subangular gravel. 



c. Sand and worn shingle. — Old sea-bed. 



d. Lower Tertiary Mottled Clays. 



e. Chalk. 



Slindon Common, immediately west of this sandpit, is every- 

 where covered by the same gravel, which is, I am informed, under- 

 laid by sands. The latter are not, however, at present exposed in 

 any section ; but in a pit on the west side of Slindon Bottom, which 

 runs parallel to, and IJ mile west of, Avisford DeU, the subangular 



