humus horizon over grey and yellowish mottled clay loam or silty clay loam
before passing to the strongly mottled subsoil clay, and is found on gentle slopes
mantled with thin loamy drift from deposits upslope. Windsor and Wickham
soils are characteristic of the flanks of the Epping Forest Ridge and particularly
of the bottoms of minor valleys which head in it. They also occupy much of the
gently undulating landscape of Chingford Plain and Walthamstow Forest.
On the relatively level ridge surface around High Beach, the Wake Arms
and in Wintry Wood, paleo-argillic stagnogley soils of the Essendon series are
found in Pebble Gravel. The interest of these soils lies in their relatively greater
age than surrounding soils, not only because the deposit in which they are
developed is old, but because the landscape has survived the glacial period more
or less intact, and may even predate the Pleistocene period. The profile is
strongly acid with very low base saturation throughout, indicating extreme
leaching and weathering. Characteristic red colours in the subsoil can be at-
tributed in part to the presence of the iron mineral haematite.
Podzolic soils
Similar processes have taken place in the development of stagnogley
podzols (Bolderwood series) but, in addition, podzolisation has differentiated
the coarse textured pebbly surface horizons. Such soils are very striking visually
with their bleached (almost white when dry) subsurface horizon, but only occur
sporadically, their presence probably indicating past rather than present
vegetation conditions and also local variations in the thickness of gravel (see
Mackney 1961).
Ground-water gley soils
Loamy soils of the Curdridge series occur around springs, in minor
depressions and locally on minor valley sides in association with Bagshot and
Claygate Beds or derived deep loamy drift. In the wettest flushes, often quite
localised but having a distinct bog vegetation, organic matter builds up at the
surface giving typical humic gley soils of the Netley series. Both are normally
strongly acid throughout, but the Netley profile shown in Table 2 is less acid and
has moderate base status due to its position downslope from an arable field
receiving lime and fertilisers. Bases leached through the soil have probably
reached the ground water, emerging at the spring site downslope. The greenish
grey subsoil colour of Netley soils with very little orange mottling indicates a
permanent state of waterlogging and reducing conditions. Similar light grey
coloured loamy soils, probably correctly assignable to the stagnohumic gley soils
group owing to impermeable drift below, are found in patches on Deer Shelter,
Rushey and Sunshine Plains where they are associated with remnants of
heather.
Peat can be found in some valley bog sites, the preserved pollen grains
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