1870,.] coDRINGTON—HAMPSHIRE AND ISLH-OF-WIGHT GRAVELS. 531 
above the rivers. Somerley Heath, and Alderholt Heath, although 
130 feet above the sea, are still 170 feet lower than the plains on 
the other side of the Avon, and immediately opposite them. 
The bottom of the valley of the Avon is shown by a dotted line 
on section No. 3. Its fall is at the rate of from 8 feet per mile 
near Hale to 3 feet per mile near the sea; so that while the tableland 
near Christchurch is but 83 feet above the valley, at Hale the high 
plain of Hatchet Green is 300 feet above it. 
Bordering on the valley between Fordingbridge and Ringwood, 
at levels approaching the tableland in height, there are terrace-like 
plains, which are well seen from the high ground on the opposite 
or western side of the valley. 
On the east of section No.3 the gravel-covered tableland stretches 
northward from Barton and Hordvwell Cliffs till it is interrupted 
by the Ayon-water valley. The tabular character is carried on by 
plains at corresponding levels near Wilverley ; and beyond an area 
comparatively low, and drained by numerous tributaries of the 
Boldre river, is the high ground near Stoney Cross and Castle 
Malwood, which is continuous with Ocknell Plain, 270 feet above 
the sea, and gravel-covered. Section No. 4 illustrates the rise of 
the tableland from the coast to the Avon-water valley and to Wil- 
verley, and shows how a prolongation of the same slope northwards 
would coincide with the high ground near Stoney Cross. 
A section of the gravel covering the tableland is seen in the cliffs 
between Poole Harbour and the entrance of the Solent. Westward of 
Poole Harbour there is no gravel on the coast, though a patch occurs 
at a high level in the valley of the Frome near Rempston House; 
but between Poole and Bournemouth the cliffs are capped with gravel 
at from 100 to 120 feet above the sea. It is from this gravel that 
the flint implements found on each side of Bournemouth are de- 
rived. The section in the cliffs is nearly the same as that shown in 
section No. 2, the general level of the tableland near the coast at 
Bournemouth being about 120 feet above the sea. Except where it 
is intersected by the Bournemouth valley or by chines, the gravel- 
bed is continuous, and from 8 to 15 feet thick, to within about a 
mile from the mouth of the Avon; there the tableland ends, and 
a cliff not more than 10 or 20 feet: high, is composed of what ap- 
pear to be the gravel-beds of an old channel of the Avon or Stour, 
which reach as low as high-water mark. Between them and the 
present mouth of the river, Hengistbury Head rises to 120 feet, 
and is capped with the older gravel. About a mile eastward from 
the mouth of the Avon, the junction of the valley-gravels with the 
gravel of the plains is seen near Highcliff, and was noticed long ago 
by Sir Charles Lyell* and by Mr. Godwin-Austeny. From this 
point to Milford the gravel is again continuous, except where 
Chuton Bunny and Becton Bunny cut through it. In Barton and 
Hordwell cliffs the thickness is now as much as from 18 to 20 feet, 
* Trans. Geol. Soc. vol. ii. 2nd series, p. 279, 
t Quart. Journ. Geol. Soc. vol. xiii, p. 45. 
