Civil Engineering Reference
In-Depth Information
system or period
(approx. age in
millions of years)
Major orogenies (mountain building) and igneous
activity (in italics)
CENOZOIC
(
=
recent life)
Quaternary
Recent
Alluvium, blown sand, glacial deposits, etc.
Extensive drift cover to most
of the bedrock
Pleistocene
At least five major ice ages separated by warmer
(2)
periods
Tertiary
Pliocene
Sand, clays and shell beds
East Anglian Crags
Miocene
Alpine orogeny
Oligocene
Igneous activity in west Scotland and Northern Ireland
Eocene
(65)
London Clay
MESOZOIC
Cretaceous
Sand, clays and chalk
Chalk, Gault Clay, Weald Clay
(
=
middle life)
Jurassic
Clays, limestones, some sands
Lias Clay, Portland Stone
Triassic
Desert marls, sandstone marls
Keuper Marl, Bunter
(250)
Sandstone
PALAEOZOIC
Newer
Permian
Breccias, marls, dolomitic limestone
Magnesian Limestone
(
=
ancient life)
Hercynian orogeny
Igneous activity
Carboniferous
Limestones, shales, coals and sandstones
Coal Measures and Mountain
Limestone
Devonian (and Old
Red Sandstone)
Siltstones, sandstones and limestones (Lacustrine
sandstones and marlstones)
Red beds in Hereford and
S. Wales
(400)
Igneous activity
Caledonian orogeny
Older
Silurian
Thick shallow-water limestones, shales and
sandstones
Rocks of Wales and Lake
District
Ordovician
Volcanic activity in the Ordovician
Cambrian
Slates, siltstones, sandstone and greywackes
Rocks of North Wales,
(600)
Central and North Scotland
PRE-CAMBRIAN
Torridonian
Schists
Rocks of North West Scotland
Sandstones
Uriconian
Lavas and tuffs (Shropshire)
Pre-Cambrian orogenies
Lewisian
