Roxby Formation

The Roxby Formation, previously known as the Permian Upper Marls, is a formation from the Guadalupian-Early Triassic of eastern England (formation dies out at Nottinghamshire).^[1] The formation is made up largely of mudstone and siltstone, reddish brown, with subordinate sandstone.^[2]

Roxby Formation
Stratigraphic range: Guadalupian-Early Triassic PreꞒ Ꞓ O S D C P T J K Pg N
Type	Group
Underlies	Sherwood Sandstone Group
Overlies	Appleby Group
Thickness	up to 1,025 metres (3,360 ft)
Lithology
Primary	Mudstone and siltstone, reddish brown, with subordinate sandstone.
Location
Region	England
Country	United Kingdom
Extent	east England
Type section
Named for	Roxby, North Yorkshire