Geology
- Broadly speaking, Cornwall consists of four granite
moorlands surrounded by an almost uninterrupted cliff
coastline extremely hostile to shipping. The four moorlands
are Bodmin Moor, the St Austell highlands, Carnmenellis
between the Fal estuary and St Ives, and the St Just uplands
north of Lands End. Many of Cornwalls rivers find their
headwaters in these moorland areas, particularly Bodmin
Moor which forms the birth place of the Camel, Fowey,
Lynher, Inny and Ottery. Cornwall reaches its highest
point at Brown Willy (420m) on Bodmin Moor, not as high
as some of the peaks on Dartmoor (600m+) in neighbouring
Devon but high enough to view the whole county, except
certain river valleys and small areas hidden behind the
other moors.
Cornwall's geology is famous for harbouring
significant metaliferous and clay deposits which, not
surprisingly, lead to a thriving mining industry developing
in the county. For example, much The St Austell granite
mass became 'kaolinized' at some point in geological time
to produce china clay deposits which have been extensively
exploited by man over the last 200 years producing gleaming
white spoil heaps in the process. The Carnmenellis moor
is notable for the number of its veins of tin, many of
which extend beyond the granite into the adjacent slate.
In many instances, weathering of the veins in the past
gave rise to alluvial tin deposits in the beds of rivers
and streams which began to be extracted by man as long
ago as the Bronze Age. Of minerals locked in the Cornish
geology, tin is the best known but copper, iron, lead,
gold, silver, arsenic, wolfram, manganese, zinc and even
uranium are all present - the greatest variety of minerals
in one area anywhere in the UK.
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Landscape
- Cornwalls landscape is characterised by large
areas of pastureland and a small amount of arable in addition
to granite moors covered with heather, rough grass, boulders
(notably in west Penwith) and bog flora. Woodland, except
along the river valleys, is extremely sparse with less
than 5% of Cornwall's total land mass being populated
by woodland habitat. On the coast, high cliffs occupy
much of the coastline which is punctuated by a profusion
of islets, stacks, coves and bays. The coastal landscape
also contains some lowland stretches, sometimes backed
by large expanses of towans or dunes such as on the south
coast near Par.
Because of Cornwall's configuration,
rivers are short compared with elsewhere in the UK, the
longest rivers in Cornwall being the Tamar (94km), the
Camel (50km) and the Fowey (35km). An intriguing feature
of many Cornish rivers is the disproportionate size of
their estuaries; for example the combined Looes, the Hayle,
the Camel and the Fowey open out in their lower reaches
in a way suggesting far longer waterways than exist in
reality. Another feature of many Cornish rivers is their
intrinsic beauty with rivers such as the tiny River Valency
receiving the attention of poet Thomas Hardy due to its
innate charm and individuality.
Wetlands form an intrinsic and functionally
extremely important part of Cornwall's landscape, ranging
from soligenious and valley mires on Bodmin Moor ( e.g
Draynes valley and Cardinham moor) to intertidal saltmarsh
wetlands such as those situated just south of Lostwithiel
(Shire Hall mire and Maderley Moor). Goss Moor, the source
of the river Fal, supports the largest inland wetland
in Cornwall, and is a mosaic of dry and wet heath, mires
and willow scrub. A particularly interesting feature of
Cornwall's wetland landscape is the Culm grassland found
in the north of the county. Culm is a wet grassland habitat
rich in rare species of flora and fauna, such as the marsh
fritillary butterfly, which unfortunately has been extensively
drained since the 1960's threatening many of the species
reliant on it.
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Climate
- The climate within Cornwall demonstrates significant
variation across the county. In general, the North West
coast is colder than the southern coastline. The warmest
districts are the Isles of Scilly and West Cornwall with
more than 1700 day degrees centigrade. Here, plant growth
ceases for only a few days each winter and on average
there are more than 250 frost free days.
In terms of rainfall, East Cornwall gets least rain -85cm
at Bude - the Centre receives the most – 126cm at
Bodmin – whilst in the West, the figures fall again
to 110cm at Falmouth. Rainfall in Cornwall demonstrates
a strongly cyclical pattern (most falls October-January)
in contrast to counties further East where rainfall is
relatively evenly distributed throughout the year.
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Flora
& Fauna - Cornwall's mild and warm climate
supports a rich vegetation cover, including subtropical
species such as palms in the southern bays. Gorse and
heathers have populated much of the moors and the northern
cliffs, whilst ferns, mosses, liverworts, lichens and
fungi are abundant across the county, some of them exotic
species introduced from abroad. In the wettest reaches
of Bodmin moor, sphagnum or bog moss can be found.
Cornwall supports many rare flower
species, particularly within the southern Lizard Peninsula
with its very individual serpentine and soil profile.
Here it is possible to find Cornish heath, mesembryanthemums,
butchers broom, early meadow grass and a plethora of clovers
including the large lizard clover, brookweed, yellow wallpepper
and many more. The North Cornwall Coast has maritime grassland,
heathland and stunted woodland of high biological value
and of national and international ecological significance.
In terms of fauna, the coastal waters
contain large populations of seals whilst porpoises and
whales are not uncommon. Cornish waters also boast good
shark populations, which has given rise to a thriving
sport fishery for species such as Mako and Porbeagle.
The broad tidal estuaries support large numbers of wading
birds whilst marshland bird species frequent the inland
bogs and mires, Bodmin moor being a breeding ground for
lapwing, snipe and curlew. On the rivers, sand martins
and kingfishers can often be seen whilst otters are returning
in significant numbers since a decline in the 1960s and
70s. Water voles still exist in Cornwall, with the Bude
Canal offering ideal habitat for this species, although
- as in many other counties - populations have suffered
serious impacts in recent years due to habitat degradation
and pollution.
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geography