Patapsco Formation

The Patapsco Formation is a geologic formation of varigated clays, sandy clays, and sand in Virginia, the District of Columbia, Maryland, Delaware, Pennsylvania, and in the subsurface of New Jersey.^[1][2] It preserves fossils such as plants and molluscs dating back to the Cretaceous period.^[1]

Patapsco Formation
Stratigraphic range: Albian–Cenomanian PreꞒ Ꞓ O S D C P T J K Pg N
Outcrop of the Patapsco Formation at Reynold's Mine, Anne Arundel County, Maryland showing the Arundel Formation overlain by the Patapsco Formation
Type	Formation
Unit of	Potomac Group
Underlies	Raritan Formation
Overlies	Arundel Formation
Thickness	200 feet (60 m)
Lithology
Primary	clay, sand
Other	silt
Location
Region	Virginia  Maryland
Country	United States
Type section
Named for	Patapsco River
Named by	William Bullock Clark (1897)[1]

See also

• Earth sciences portal
• Virginia portal
• Maryland portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Virginia
• List of fossiliferous stratigraphic units in Maryland
• Paleontology in Virginia
• Paleontology in Maryland