Geological Features. 
351 
lonfT, ^11^^ one broad at the widest point, also in two or tlnec 
irre<?ular patches round Sandown in the S.E. 
The northern half of the island is occupied by plains of the 
Eocene formation. Belonging to the Lower Eocene is a narrow 
fringe (seldom appearing- at the surface) of plastic and London 
clay, skirting the central chalk axis of the island. This is suc- 
ceeded by another edging or fringe, J mile broad, of the upper, 
middle, and lower Bagshots ; thence extend to the coast the 
Headon, Osborne, and Bem bridge series. The last is the 
greatest in superficial extent. All these belong to the middle 
Eocene. The upper Eocene is seen in the Hempstead beds near 
Yarmouth and at Parkhurst. 
Gravel caps some of the downs of the central range, as at 
Freshwater, Headon-hill (where it is 60 feet thick), and St. 
George's Down above Arreton (where it is called " the red 
gravel "), and all the hills of the northern portion of the island. 
It is spread in an apparently continuous bed over the surface at 
the eastern extremity, at Foreland and St. Helen's. Between 
Ryde and East Cowes it is 20 or 30 feet thick, crowning the 
hills. It occurs also in the N.W., between West Cowes and 
Yarmouth, on the summit of Hempstead Hill, and in Parkhurst 
Forest. There are also beds of sand and gravel, with peat under- 
neath them, in the south-western basin. 
I estimate the areas of these different formations thus : — 
Sq. miles. 
Central chalk range 21 
Southern ditto 8 
Intervening greensand 45 
Weald clay, S.W 5 
Ditto, S.E. .. 3 
Bagshot 14 
Osborne and Headon 10 
Bembridge, N.W 28 
Ditto, N.E 16 
Hempstead 6 
156 
From this, it will be seen that the Bembridge series comprises 
no less than 44 square miles of the northern half of the island. 
These are composed of an upper and lower bed of marl, which 
last rests on an oyster-bed, which again rests on limestone. The 
three upper beds are argillaceous, the lower is calcareous, and 
irom its distribution takes local names from Binsted, Cowes, 
Gurnet Bay, Calbourn, Dodpits, and Sconce, being occasionally 
separated by shales and beds of marl. 
Thus we have, in this little island, a repetition of the mainland 
in miniature, or rather a model, within a circumference of 56 miles. 
