But so far is this from being
the case in Great Britain, that nowhere have geologists found more difficulty in
drawing the line of separation than between the Secondary and Primary series.
The obscurity has arisen from the great resemblance in colour and mineral
character of the Triassic and Permian red marls and sandstones, and the scarcity
and often total absence in them of organic remains. The thickness of the strata
belonging to each group amounts in some places to several thousand feet; and by
dint of a careful examination of their geological position, and of those fossil,
animal, and vegetable forms which are occasionally met with in some members of
each series, it has at length been made clear that the older or Permian rocks
are more connected with the Primary or Palaeozoic than with the Secondary or
Mesozoic strata already described.
The term Permian has been proposed for this group by Sir R. Murchison, from
Perm, a Russian province, where it occupies an area twice the size of France,
and contains a great abundance and variety of fossils, both vertebrate and
invertebrate.
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