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THE ESSEX NATURALIST
is an area of varied and interesting geology including the London
Clay with its outliers of Claygate and Bagshot Beds on hills cap-
ped by glacial gravels. To the north the London Clay is covered
by the Chalky Boulder Clay which marks the southernmost limit
of the Glaciation in this part of Essex. The soils in this area not
only differ as to their geological parent material but also accord-
ing to the degree of drainage and leaching they show. 29 such
soil series are shown on the map legend, a soil series being de-
fined as a group of soils with similar profiles formed in lithologic-
ally similar parent materials.
Also published for the same area are a Soil Drainage map
which groups the soils according to the drainage they show, and a
Land Use Capability Map which groups soils according to their
capability and adaptability for agricultural crops.
The record accompanying these maps describes the soils in
full and also explains the terminology and the methods of
mapping. But the record is also valuable as a source of reference
for the area. As well as the soils description it contains an account
of the map areas including its physiology, climate, landscape
development and geology. This being followed by an introduction
to Soil Classification and Soil Mapping. The detailed description
of the soils is according to the position in the landscape, thus
soils on plateau sites are differentiated from those on plateau
margins and again from the soils of footslopes and valley floors.
There is a section on Agriculture and on land drainage, this last
including a brief account of the history of land drainage.
Numerous tables list meteorlogical data and also data of agri-
cultural significance such as potential transpiration and soils
moisture deficit. Text figures include rainfall and soil parent
materials and also a series of block diagrams showing pictorially
the relationship of the soil types to the landscape.
Currently being prepared are the maps and record of the area
around Burnham on Crouch being sheet TO 99 of the Ordnance
Survey. This includes areas of brickearth and alluvium of the
now drained Essex Marshes and islands. Currently being sur-
veyed is an area to the east of Colchester (TM 12) and also parts
of TL 71 to the north of Chelmsford.
The publications mentioned above and other published sur-
veys of England and Wales may be obtained from the Soil Survey
of England and Wales at Rothamsted Experimental Station,
Harpendon, Herts., where additional information on the soils may
be obtained.
References
Soils of the Saffron Waldon District by A. J. Thomasson. Special Survey
No. 2. 1969. Price 55p with map or 25p without map.
Soils in Essex 1. by R. G. Sturdy. Soil Survey Record No. 7. 1971. Price
£1.25 with three maps or 50p without maps Individual maps 25p
each.