Info on the the Cornish section of the South West Coast Path which runs for 258 miles from Marsland Mouth to Cremyll.
Basic Geology :-
Devonian rocks 417 - 354 million years old (myo ), form the basis of most of Cornwalls Geology.
Subject to deformation during the Variscan Orogeny about 380 - 280 myo.
These are hard rocks, resistant to erosion, often resulting in dramatic sea cliffs .
Carboniferous -
From Tintagel along the North Cornwall Coast to the border with Devon are Carboniferous Rocks (354-290 myo),
intensively folded and faulted by Tectonic Plate movements during the Variscan Orogeny.
The Lands End Penninsula - The Granite Coast
Dominated by Intrusions of Granite at the end of the Variscan Orogeny about 300 - 280 mya.
The Isles of Scilly , Bodmin Moor were also formed at this time .
Fluids escaping from the cooling Granite were responsible for ores rich in Tin , Copper , Lead and Zinc.
Heat from the Granite Intrusion metamorphised the surrounding 'country rocks' into a rich variety of rock types.
The Lizard Peninsula -
Is a special area with rocks rare in the British Isles , formed when rocks from between the Earths Crust and the Mantle where thrust upwards due to tectonic plate movements.
Hydrothermal Waters altered Peridotite ( the dominant rock of the upper mantle) into the Lizards famous Serpentine Rock.
Mining / Engine Houses :-
Cornish Tin found in streams was first used in prehistoric times for the production of Bronze.
Britain became known as the 'Tin Islands'.
Cornish Granite contains high amounts of Tin , Tungsten and Copper in cocentrated lodes.
In the C16 miners moved underground to seek out the source Lodes.
Pre 1870 Cornwall was the Worlds leading producer of Tin.
Copper mining developed in C18 and in the 1830's Cornwall dominated world copper production.
The steam driven beam engine , housed in the famous Cornwall Engine Houses allowed groundwater that could flood the mines to be removed and at the height of the Mining Industry there were more than 600 steam engines working in Cornwall.
Around 3,000 Engine houses were built , with 200 still surviving.