The Southwest Region - Southern England - page 72

er younger, less altered sediments. In a few localities around Plymouth ( b1 ) there are
Devonian limestones, similar to the well-known limestones around Torquay ( d1 ) and
Chudleigh ( d9 ). The settings in which these Devonian sediments may have formed are
illustrated in Figure 38, in the general section of this chapter.
The youth of the coastal scenery of this Landscape combines with the vigour of
many of the processes operating to make it much more distinctive and dramatic than
the inland scenery. In the west of Area 2, cliffs characterise the Cornish section of the
south coast and often intersect deeply incised valleys that are clearly older features
(Fig. 71).
Cornwall and Devon are separated from each other in this Area by the River
Tamar, and this meets the south coast in a large drowned valley system around which
Plymouth ( b1 ) has grown (Fig. 72). Plymouth Sound is one of the best natural harbours
in the Southwest and the historical naval importance of this city is the result. Similar,
but smaller, valley systems (sometimes called rias ) are common all along this stretch
of coast, as they are further west in Area 1. Flooded valleys form the estuaries of the
River Fowey, east of St Austell, and farther east still at Salcombe ( b3 ) and Dartmouth
( b8 ).
FIG 71. Polperro, on the south Cornwall coast. (Copyright Dae Sasitorn & Adrian Warren/
www.lastrefuge.co.uk)