248 On the Agricultural Geology of the Weald. 
the district. The phosphate of lime occurs as nodules in a loose 
ferruginous matrix. Fossils are abundant ; they are generally 
in fragments, and are always phosphatic. This bed is of small 
thickness, rarely exceeding a foot ; but occasionally other thin 
layers occur, and sometimes there are loose nodules in the sand 
just below. When exposed to the weather, this layer hardens 
and holds up water. The lower part of the Gault when 
undrained, and with the crust unbroken, is said to be often wet 
and poor from this cause. 
The Middle Gault, from the quantity of carbonate of lime it 
contains, is best adapted for manure. It is sometimes dug for 
this purpose, chiefly so in West Surrey and Hants, where it is 
applied to light land with great success. This stratum, and 
the top layer of the Upper Greensand, are the only beds 
occurring in the Weald to which the term "marl" can fairly be 
applied. The " chalk-marl " is a calcareous rock containing 
some clay, and the so-called " marls " of the Wealden are 
simply shales, with very little, if any, lime. 
The Gault is but little covered with drift, and chiefly so 
where crossed by the rivers, just before they pierce the Chalk 
escarpment. The largest area thus covered is on the River 
Stour, to the north of Ashford. The gravels of the Wey, near 
Farnham ; of the Darent, north of Sevenoaks ; and of the Arun, 
at Hardham, also overlie Gault clay. On the north of Maid- 
stone, besides the ordinary river-gravel of the Medway, there is 
a covering, some 12 feet or more thick in places, of chalky wash, 
containing some flints. It forms a marly soil less stiff than the 
Gault itself. Perhaps there is occasionally some wash resembling 
this at the foot of the Chalk escarpment in other places, but it 
certainly is not common, and cannot anywhere be of great 
extent. 
In Surrey, from about Wotton, westwards, the dip of the beds 
is high and the Gault thin, so that little is seen of it. On the 
borders of Hants, at the north-west corner of the Weald, i% 
spreads over a considerable area at Alice Holt Wood, the soil of 
which is a wet yellow clay containing some flints. Here is the 
greatest elevation attained by the Gault in the Wealdeii area. 
Lower Greensand. 
This formation offers in every respect a marked contrast to? 
that last described. It always rises up from beneath the Gault 
valley and forms hilly ground, often attaining to a great heights 
It varies very much in composition, and, consequently, in 
agricultural character. Generally it consists of four subdivisions, 
as is the case in Kent, East Surrey, and West Sussex. In West 
