Marlstone Rock Formation
Stratigraphic range: Pliensbachian–Toarcian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Lias Group
Underlies	Whitby Mudstone Formation
Overlies	Dyrham Formation, Charmouth Mudstone Formation (East Midlands Shelf northwards)
Thickness	10 metres (33 ft)
Lithology
Primary	Limestone, sandstone
Other	Mudstone, Ironstone
Location
Country	United Kingdom
Extent	East Midlands Shelf and Worcester Basin (Mendips to Market Weighton).
Type section
Location	Jeffries Brickworks, near Stonehouse

The Marlstone Rock Formation is a geological formation in England. It dates to the Early Jurassic, it consists of "Sandy, shell-fragmental and ooidal ferruginous limestone interbedded with ferruginous calcareous sandstone, and generally subordinate ferruginous mudstone beds", with ironstone.^[1]