Geology of Lancashire

This article covers the modern ceremonial county of Lancashire which includes the boroughs of Blackpool and Blackburn with Darwen but not those southern parts of the historic county of Lancashire which have since 1974 formed a part of the counties of Merseyside and Greater Manchester nor the northernmost part which now forms a part of Cumbria.

The geology of Lancashire in northwest England consists in the main of Carboniferous age rocks but with Triassic sandstones and mudstones at or near the surface of the lowlands bordering the Irish Sea though these are largely obscured by Quaternary deposits.

Carboniferous

Rocks originating in the Carboniferous Period underlie the uplands of eastern and north Lancashire. They comprise limestones, mudstones, siltstones and sandstones of the Coal Measures, Millstone Grit Group and Carboniferous Limestone Supergroup.

Permian

A small area of rocks originating in the Permian Period occurs near Lancaster, Morecambe and Glasson Dock though it is entirely obscured by recent deposits and is known only from borehole cores. These are the Collyhurst Sandstone of the Appleby Group and the sandstones, mudstones and evaporites of the overlying Cumbrian Coast Group. There are also narrow bands of these rocks (Manchester Marls and Collyhurst Sandstone) to the north and south of Preston though again they are generally buried beneath glacial till.

Triassic

Lancashire's coastal plain is underlain by sedimentary rocks laid down during the Triassic Period comprising sandstones, siltstones and mudstones though outcrops are restricted to those areas which are not covered by thick superficial deposits.

Quaternary

The larger part of the Lancashire Plain is covered by a thick mantle of glacial till. These deposits are the legacy of the over-riding of the area on several occasions by glacial ice during the past 2 million years. The present distribution of deposits and the landforms to which they give rise are largely the result of the last ice age, the Devensian which peaked around 22-20,000 years ago. Drumlins caused by the moulding of sub-glacial sediments are a significant feature of the landscape in the north of the county.^[1]

References

See also

• Geology of the United Kingdom
• Geology of England
• List of geology of English counties
• Geology of Cheshire
• Geology of Yorkshire

Ceremonial county of Lancashire North West England Portal Unitary authorities Blackburn with Darwen Blackpool Boroughs or districts City of Lancaster City of Preston Burnley Chorley Fylde Hyndburn Pendle Ribble Valley Rossendale South Ribble West Lancashire Wyre Major settlements Accrington Adlington Bacup Barnoldswick Blackburn Blackpool Brierfield Burnley Carnforth Chorley Clayton-le-Moors Cleveleys Clitheroe Colne Darwen Earby Fleetwood Garstang Great Harwood Haslingden Kirkham Lancaster Leyland Longridge Lytham St Annes Morecambe Nelson Ormskirk Oswaldtwistle Padiham Penwortham Poulton-le-Fylde Preesall Preston Rawtenstall Rishton Skelmersdale Thornton Wesham Whitworth See also: List of civil parishes in Lancashire Rivers Calder Darwen Douglas Hodder Irwell Lune Ribble Wyre Canals Lancaster Leeds and Liverpool Topics Flag Parliamentary constituencies Places Schools SSSIs Country houses Grade I buildings Grade II* buildings History Museums Lord Lieutenants High Sheriffs