Geologic units in Queen Anne's county, Maryland

Upland Deposits (Eastern Shore) (Quaternary) at surface, covers 72 % of this area

Gravel, sand, silt, and clay. Mostly cross-bedded, poorly sorted, medium- to coarse-grained white to red sand and gravel; boulders near base; minor pink and yellow silts and clays; (Wicomico Formation of earlier reports); thickness 0 to 90 feet, locally thicker in paleochannels.

Lowland Deposits (Quaternary) at surface, covers 21 % of this area

Gravel, sand, silt, and clay. Medium- to coarse-grained sand and gravel; cobbles and boulders near base; commonly contains reworked Eocene glauconite; varicolored silts and clays; brown to dark gray lignitic silty clay; contains estuarine to marine fauna in some areas (includes in part Pamlico, Talbot, Wicomico and Sunderland Formations of earlier reports); thickness 0 to 150 feet.

Chesapeake Group; Calvert Formation (Miocene) at surface, covers 7 % of this area

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.

Chesapeake Group (Tertiary) at surface, covers < 0.1 % of this area

Bluish gray silt with quartz sand and some shell beds.

Pamunkey Group; Aquia Formation (Paleocene) at surface, covers < 0.1 % of this area

Dark green to gray-green, argillaceous, highly glauconitic, well-sorted fine- to medium-grained sand; locally indurated shell beds; thickness 0 to 100 feet.