rocks, the
coal-fields, the Permian strata and the Triassic formations, the
last-named, while sweeping round the southern extremity of the
Carboniferous axis of the uplift from its eastern and western flanks,
spread out in a large sheet over the midland counties. (2) The second
striking feature is the regular succession of Jurassic and Cretaceous
rocks which crop out in almost unbroken lines from the coast of
Dorsetshire, whither they appear to converge, to the Cleveland Hills
and the Yorkshire coast. Lying upon the Cretaceous rocks in the S.E.
of England are the two Tertiary basins of London and Hampshire,
separated by the dissected anticline of the Weald.

[Illustration: Map of ENGLAND.

Legend:

_Recent & Pleistocene_ _Old Red Sandstone & Devonian_
_Tertiary_ _Silurian_
_Cretaceous_ _Ordovician_
_Jurassic_ _Cambrian_
_Trias_ _Metamorphic Group_
_Permian_ _Volcanic Rocks_
_Coal Measures, Carboniferous_ _Basic Intrusive Rocks_
_Millstone Grit Series & Culm_ _Granite & Acid Intrusive Rocks_
_Lower Carboniferous_]

The older rocks in England occupy relatively small areas. Pre-Cambrian
rocks are represented by the gneisses of Primrose Hill and schists of
Rushton in Shropshire; by the gneisses forming the core of the Malvern
Hills, and by the ancient volcanic and other rocks of the Wrekin,
Charnwood Forest and Nuneaton. The slates of the Long Mynd, on the
Shropshire border, belong to this system. Cambrian strata appear in
Shropshire in the form of sandstones and quartzites; in the Malvern
Hills they are black shales, while in the Lake District they are
represented by the Skiddaw slates. Next in point of age comes the
Ordovician system, which is well developed upon the Shropshire border
and in the Lake District. In the same two areas we find the Silurian
rocks, shales and limestones with grits and flags. In N. and S. Devon
are the Devonian limestones, grits and shales; the corresponding Old
Red Sandstone type of the system (marls and sandstones) being exposed
over a large part of Herefordshire, stretching also into Shropshire
and Monmouth. Next in order of succession comes the Carboniferous
system, with shales and limestones in the lower members, grits,
sandstones and shales--the Millsto