Columbia Formation (DEPSc;0)

State	Delaware
Name	Columbia Formation
Geologic age	Pleistocene
Comments	This unit was described on the 1966 state map, but was represented by a pattern rather than a specific color and map symbol. Thus, no original map label is recorded and map symbol1 was made up for this digital product.
Primary rock type	sand
Secondary rock type	gravel
Other rock types	clay or mud
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Sand Minor Unconsolidated > Coarse-detrital > Gravel Incidental Unconsolidated > Fine-detrital > Clay
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.