Environmental Engineering Reference
In-Depth Information
FIG
22.
Limekiln at Mewslade. Lime making was one of the earliest industrial activities in the area. (Harold Gren-
fell)
TABLE
6.
The soils of Gower. (Adapted and simplified from Wade
et al
., 1994)
UNDERLYING ROCK OR OTHER PARENT
MATERIAL
DOMINANT
SOIL
SOIL CHARACTERISTICS
GROUP
Dune sand
Raw sands
Calcareous windblown sand; thin humic
topsoils only present on stabilised dunes
and frequently buried. Gleyed soils and
peat in hollows.
Limestone and Triassic 'gash' breccia Brown earths
Well-drained loamy, or loamy over
clayey soils, shallow in places, espe-
cially on steep slopes and crests with
'
rendzina
' in rocky areas.
Fluvioglacial sands and gravels
Brown earths
Deep well-drained loamy soils.
Millstone Grit and Coal Measures
Brown podzolic
soils
Well-drained loamy soils over sand-
stone, usually on steep slopes. Heavy
clays on shales - slowly permeable, sea-
sonally waterlogged soils with a peaty
surface, usually on valley floors.
Devonian conglomerate and sandstone Podzols
Well-drained, very acid sandy soils with
a bleached subsurface horizon over con-
glomerate. Associated with less acid
well-drained reddish loamy soils over
sandstone and siltstone.
Till
Stagnohumic gley
soils
Heavy stony clays - very acid, slowly
permeable seasonally waterlogged
loamysoilswithapeatysurfacehorizon.
Estuarine alluvium
Alluvial gley soils Loamy alluvial soils with high ground-
water. Saline and partially anoxic in
marshes. Sand or soft mud on intertidal
flats.
The soils on the ridges of the Old Red Sandstone outcrops are mainly rocky, coarse loamy podzols.
They are found under heathland vegetation and below a surface accumulation of acid plant debris there is
a thick bleached sandy horizon which overlies a dark zone of humus, iron and aluminium accumulation.
This passes to a yellowish red horizon enriched with hydroxides of iron and aluminium. The associated
fine loamy brown earths and brown podzolic soils lie mainly under grassland with associated bracken
Pteridium aquilinum
and their distribution is related to the underlying rocks. The podzols are very acidic
withpHvalues lessthan4.0,while theassociated brownearths andbrownpodzolic soilsareonlyslightly
less acid, with pH values around 4.5.
