Metal ores have been mined in cornwall since ancient metal work first began.  The region
is a source of many metals including tin and copper.  The mineralisation in Cornwall is largely
the result of effects associated with extensive igneous intrusions.  There are is wide
diversity of exotic mineral varieties associated with the ore deposits.

Preserved engine houses at abandoned mines.

The geology of Cornwall is predominated by igneous rocks.  The large intrusive granite
masses such as Dartmoor and Bodmin Moor are among the most obvious examples.
These igneous rocks were intruded into strongly deformed metamorphosed sediments in the
Late Carboniferous and Early Permian times.  Cornwall aslo has metamorphic rocks and
metamorphosed oceanic rocks.

At the famous Lizard ophiolite (upthrust and preserved ancient oceanic crust) rock
varieties including gabbro, peridotite, serpentinite, granite, basalt, amphibolites and
gneiss may all be found.  Olivine gabbro is also present here.

For those of you who are familiar with the moho transition, this is preserved at Lizard and
may be seen as a change in rock type from peridotite to gabbro.  It is possible to stand
with one foot on either side of the moho here.

Granite (light) below darker country rock.  The thin band of darker colour just near
the top of the granite is a band of tourmaline crystals.

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