Cullaidh Shale Formation

The Cullaidh Shale Formation is a geological formation in Scotland, and the lowermost unit of the Great Estuarine Group. It is Bajocian in age. The lithology largely consists of organic rich mudstone and shales, including oil shale developed near the base.[1]

Cullaidh Shale Formation
Stratigraphic range:
Black shale of the Cullaidh Shale Formation overlain by a sill
Type	Geological formation
Unit of	Great Estuarine Group
Underlies	Elgol Sandstone Formation
Overlies	Bearreraig Sandstone Formation
Thickness	up to 6 metres (20 ft)
Lithology
Primary	Shale, Mudstone
Other	Sandstone
Location
Region	Europe
Country	Scotland
Extent	Inner Hebrides