In southern
England, the Lias Group is often divided into Lower, Middle and Upper subgroups. In Southern England the Lias is divided into the following
formations (from top to base): •
Bridport Sand •
Beacon Limestone •
Dyrham Formation •
Charmouth Mudstone •
Blue Lias In the East Midlands Shelf the Lias is divided into the following
formations (from top to base): •
Whitby Mudstone •
Marlstone Rock • Charmouth Mudstone •
Scunthorpe Mudstone In the
Cleveland Basin in Yorkshire the Lias is divided into the following
formations (from top to base): • Whitby Mudstone •
Cleveland Ironstone •
Staithes Sandstone •
Redcar Mudstone In
South Wales only the Blue Lias is present. The Lias is underlain by the Late Triassic
Penarth Group, and overlain by the
Inferior Oolite in most of England and the
Dogger Formation or
Ravenscar Group in the Cleveland Basin. In some areas there is a
stratigraphic hiatus, and the rocks are overlain by Cretaceous marine sediments. There are restricted outcrops of Lias rocks on the west coast of
Scotland where, in the Sea of the Hebrides depositional basin on
Skye,
Raasay and
Mull, the
Broadford Beds Formation,
Pabay Shale Formation and overlying
Scalpay Sandstone Formation are assigned to the Lias Group. In
Dutch lithostratigraphy, the name Lias has no official status, however, it is often used for the lower part of the
Altena Group in the subsurface of the Netherlands and the southern North Sea. In northern Germany, the Lias Group consists of nine formations (from top to base): •
Opalinuston •
Dörnten-Formation •
Posidonia Shale •
Amaltheenton •
Capricorn Formation •
Raricostaten-Formation •
Arieten Sandstone •
Liassicus Sandstone •
Psilonoten Sandstone ==See also==