Geoscience Reference
In-Depth Information
One of the most obvious doglegs is in the upper reaches of the Stour valley
(
b5
), which links the famous Suffolk villages of Clare, Cavendish and Long Melford.
These villages are famous for the preservation of large numbers of beautiful houses
and churches, reflecting the fifteenth-century peak of prosperity in the wool and textile
trade in this area. Flints from the Chalk have been widely used in building here, and the
timber frames, often painted and ornamented into surface patterns (pargetting), along
with their Chalk-based plaster work, are particularly attractive.
Northeastward of the A14 trunk road and the Bury St Edmunds to Ipswich railway
(Fig. 245), the Chalk hills landscape of north-central Suffolk (
b6
) is a southern exten-
sion of the Breckland, discussed further under Area 16. The landscape here is lower
than the Chalk hills to the southwest, and is widely covered by a gently undulating
sheet of Anglian ice-laid material, locally eroded by valleys that penetrate to the Chalk
bedrock.
Landscape C: The Essex Claylands (Early Tertiary)
This Landscape is defined by the Early Tertiary age of the bedrock underlying it. The
hill-shaded elevation maps (Figs 245 and 246) make it clear that the size and form of
the hills and valleys is remarkably little influenced by the change of bedrock, which
continues to be capped widely by Anglian ice-laid material.
As with the southern part of the Chalk hills (Landscape
B
), present-day erosion
of this Landscape is being carried out by a number of rivers draining southwards and
eastwards towards the sea. At locality
c1
in Figure 247 there is a second major dogleg
on the River Stour, in one of the most clearly developed of these widened valley sys-
tems. It has steep valley walls, cut through Anglian ice-laid material resting on Early
Tertiary mudstone bedrock. In the case of both materials, undermining by the river will
have tended to cause collapse, which has produced the steep slopes that form the valley
walls. Another feature is the presence of small, steep-sided branch valleys, often with
their own branches. These are probably due to local collapses of the valley heads under
the freezing and thawing conditions that existed during much of the Ice Age.
Figure 250 shows an early pen and watercolour drawing made by John Constable
in 1800, when he was only 24. It is a beautifully careful representation of the coach
road leading across the flat floodplain of the Stour valley, the distinct northern wall
of which is visible in the background. The present view from this locality is obscured
by large trees, and the entire valley crossing at this point has now been heavily engin-
eered to reduce gradients on the busy A12 trunk road running between Colchester and
Ipswich. Constable's drawing shows very clearly the distinctive slopes of the valley
walls to north and south compared to the flatness of the floodplain floor (Fig. 251), al-
