This is a representation of the rock types that occur at or near
the surface on the Isle of Man. Most of the rocks are in fact covered
by a thin layer of soil so that the map is an interpretation - the
geology is extrapolated from areas where the rocks are exposed such
as at the coast or in quarries. A large part of the Island is composed
of a suite of rocks collectively known as the Manx
Group.
These were originally sediments deposited on the sea bed 490-
470 million years ago.
