Craven Group

Craven Group
Craven Group
Stratigraphic range: Chadian-Yeadonian sub-stages of Carboniferous period
Type	Group
Sub-units	Hodder Mudstone, Hodderense Limestone, Pendleside Limestone, Bowland Shale formations
Underlies	Millstone Grit Group
Overlies	Bowland High Group, Clwyd Limestone Group
Thickness	up to 5000m
Lithology
Primary	mudstone, limestone
Other	sandstone, siltstone, chert
Location
Region	northern England, English Midlands and northeast Wales
Type section
Named for	Craven district

The Craven Group is a lithostratigraphical term referring to the succession of mudstone and limestone rock strata which occur in certain parts of northern and central England and northeast Wales in the United Kingdom within the Chadian to Yeadonian sub-Stages of the Carboniferous Period. Other lithologies including sandstones, siltstones and chert occur within the group.^[1] The Group is subdivided into numerous formations, some of which previously enjoyed group status. In stratigraphic order (uppermost/youngest at top), these are:

Bowland Shale Formation (mudstone and siltstone)
Pendleside Limestone Formation (interbedded limestone and mudstone, conglomerate)
Hodderense Limestone Formation
Hodder Mudstone Formation (limestone and mudstone)

The Craven Group unconformably overlies the Bowland High Group and elsewhere the Clwyd Limestone Group. It is succeeded (overlain) by the Millstone Grit Group^[2]

References

^ http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=CRAV BGS Lexicon of named rock units: Craven Gp
^ British Geological Survey 1:625,000 scale geological map Bedrock geology: UK South (5th edn) BGS, Keyworth, Notts