Chesapeake Group (DETch;0)

State	Delaware
Name	Chesapeake Group
Geologic age	Tertiary
Original map label	Tch
Comments	Miocene, may be overlain locally by the Pleistocene Columbia Formation
Primary rock type	silt
Secondary rock type	sand
Other rock types
Lithologic constituents	Major Unconsolidated > Fine-detrital > SiltBluish gray silt with quartz sand and some shell beds. Minor Unconsolidated > Coarse-detrital > SandBluish gray silt with quartz sand and some shell beds.
Map references	Spoljaric, Nenad and Jordan, Robert R., 1966, Generalized Geologic Map of Delaware, State of Delaware, Delaware Geological Survey, scale ca. 1:300,000.
Unit references	Spoljaric, Nenad and Jordan, Robert R., 1966, Generalized Geologic Map of Delaware, State of Delaware, Delaware Geological Survey, scale ca. 1:300,000.
Geographic coverage	Kent - New Castle - Sussex