The Potomac Formation consists of Lower Cretaceous to Upper Cretaceous strata located in Delaware, Maryland, and New Jersey, in the eastern United States.
Flora found in the strata include large cycads.
- ^ Ward LF (1894) Recent Discoveries of Cycadean Trunks in the Potomac Formation of Maryland Bulletin of the Torrey Botanical Club, Vol. 21, No. 7 (Jul. 20, 1894), pp. 291-299 doi:10.2307/2477918