Raritan Formation

Red, white, gray, and black clay and poorly lithified white sand. Black clay contains lignite fragments and pyrite and siderite nodules. Exposed only in a few wave-cut bluffs on Block Island, but inferred to have originally onlapped both the Esmond-Dedham and Hope Valley subterranes. This unit may occur as large glacial erratic blocks enclosed in till, and may not represent in situ bedrock.
State Rhode Island
Name Raritan Formation
Geologic age Cretaceous
Lithologic constituents
Major
Unconsolidated > Fine-detrital > ClayRed, white, gray, and black clay. Black clay contains lignite fragments and pyrite and siderite nodules.
Unconsolidated > Coarse-detrital > Sandpoorly lithified white sand
Comments Part of Avalon Terrane
References

Hermes, O.D. (comp.), Gromet, L.P. (comp.), Murray, D.P. (comp.), Hamidzada, N.A., Skehan, J.W., and Mosher, S., 1994, Bedrock geologic map of Rhode Island: Rhode Island Map Series No. 1, Kingston, Rhode Island, scale 1:100,000.

NGMDB product
Counties Washington