These
Bovey Tracy lignites are of Lower Miocene age, and they are
lacustrine in origin. Also of Lower Miocene age are the so-called
"Hempstead Beds" of Yarmouth in the Isle of Wight. These attain a
thickness of less than 200 feet, and are shown by their numerous
fossils to be principally a true marine formation. Lastly, the
Duke of Argyll, in 1851, showed that there existed at Ardtun, in
the island of Mull, certain Tertiary strata containing numerous
remains of plants; and these also are now regarded as belonging
to the Lower Miocene.
In _France_, the Lower Miocene is represented in Auvergne, Cantal,
and Velay, by a great thickness of nearly horizontal strata of
sands, sandstone, clays, marls, and limestones, the whole of
fresh-water origin. The principal fossils of these lacustrine
deposits are _Mammalia_, of which the remains occur in great
abundance. In the valley of the Loire occur the typical European
deposits of Upper Miocene age. These are known as the "Faluns,"
from a provincial term applied to shelly sands, employed to spread
upon soils which are deficient in lime; and the Upper Miocene
is hence sometimes spoken of as the "Falunian" formation. The
Faluns occur in scattered patches, which are rarely more than 50
feet in thickness, and consist of sands and marls. The fossils
are chiefly marine; but there occur also land and fresh-water
shells, together with the remains of numerous Mammals.
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