Chesapeake Group; Calvert Formation

Plum Point Marls Member: Interbedded dark green to dark bluish-gray, fine-grained argillaceous sand and sandy clay; contains prominent shell beds and locally silica-cemented sandstones; and Fairhaven Member: Greenish-blue diatomaceous clay, weathers to pale gray; pale brown to white, fine-grained argillaceous sand; and greenish-blue sandy clay; total thickness 0 to 150 feet.
State Maryland
Name Chesapeake Group; Calvert Formation
Geologic age Miocene
Lithologic constituents
Major
Unconsolidated > Coarse-detrital > Sand
Unconsolidated > Fine-detrital > Clay
Incidental
Sedimentary > Clastic > Sandstone
Stratigraphic units Chesapeake Group
References

Cleaves, E.T., Edwards, J., Jr., and Glaser, J.D., 1968, Geologic Map of Maryland: Maryland Geological Survey, Baltimore, Maryland, scale 1:250,000.

In 1995 the Water Resources Division of the U.S. Geological Survey digitized the geologic map of Maryland from the 1968 paper map (Reference MD001). Information about products from the Maryland Geological Survey can be found at http://www.mgs.md.gov/.

NGMDB product
Counties Anne Arundel - Calvert - Caroline - Charles - Kent - Prince George's - Queen Anne's - Saint Mary's - Talbot