Geoscience Reference
In-Depth Information
Penhale Sands, north of Perranporth, are a spectacular example of the way that gales
from the west can move beach sand up to 2 km inland. Because of the variation in the
killas bedrock, some headlands are long and the inlets are narrow enough to develop
fast tidal flows, capable of forming large, regular ripples as seen in the foreground of
Figure 62.
On the south coast, storm-built sandy beaches have also formed, for example at
Newlyn (
c8
), Praa Sands (
c5
) and at the mouth of Helston valley south of Porthleven
(
c6
). Further east, the coastline is much more sheltered and the scenery is dominated
by the drowned valleys and quiet inlets of the Carrick Roads (
c7
).
AREA 2: EAST CORNWALL AND SOUTH DEVON
This Area straddles the boundary between Cornwall and Devon (Fig. 64). In terms of
the coastlines of the Southwest, it includes a small stretch of the north coast near Tint-
agel, and a large section of the south coast from St Austell, via Plymouth and Start
Point, to Torquay and Exmouth (Fig. 65).
In the general section of this chapter, the early geological history of the Southwest
Region as a whole has been outlined, particularly the evolution of the Variscan moun-
tain belt. Younger episodes in the region have also been discussed, involving river and
valley erosion of the landscape, the effects of the Ice Age and the changes in the coast-
line that have resulted from the most recent (Flandrian) rise in sea level.
In the sections below we shall consider more local features of the scenery in this
Area, dividing it into four distinct Landscapes (labelled
A
to
D
), each underlain by a
different kind of bedrock (Fig. 66).
FIG
64.
Location map for Area 2.
