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Mineral Resources > Online Spatial Data > Geology > by state > Virginia Geology

Geologic units in Lancaster county, Virginia

Windsor Formation (Tertiary-Quaternary) at surface, covers 55 % of this area

Windsor Formation - Interbedded gravel, sand, silt, and clay; at altitudes to 85-95 ft. (top of unit).

Lithology: gravel; sand; silt; clay or mud

Shirley Formation (Quaternary) at surface, covers 4 % of this area

Shirley Formation - Interbedded gravel, sand, silt, clay, and peat; at altitudes to 35-45 ft. (top of unit).

Lithology: gravel; sand; silt; clay or mud; peat

Tabb Formation: Lynnhaven and Poquoson Members (Quaternary) at surface, covers 12 % of this area

Tabb Formation: Lynnhaven and Poquoson Members - Undifferentiated Qtl, Qts.

Lithology: sand; silt

Tabb Formation; Sedgefield Member (Quaternary) at surface, covers 17 % of this area

Tabb Formation; Sedgefield Member - Pebbly to bouldery, clayey sand and shelly sand, at altitudes to 30 ft. (top of unit).

Lithology: sand

Marsh and Intertidal Mud Deposits (Quaternary) at surface, covers 0.1 % of this area

Marsh and Intertidal Mud Deposits - Organic-rich clay and silt

Lithology: clay or mud; silt

Chesapeake Group (Tertiary) at surface, covers 5 % of this area

Chesapeake Group - Fine- to coarse-grained sand, silt, clay; variably shelly and diatomaceous

Lithology: sand; silt; clay or mud

Alluvium (Quaternary) at surface, covers 2 % of this area

Alluvium - Poorly sorted organic material, clay, sand, and rounded pebbles and cobbles

Lithology: alluvium; clay or mud; sand

Beach Sand and Dune Sand Deposits (Quaternary) at surface, covers 0.4 % of this area

Beach Sand and Dune Sand Deposits - Fine- to coarse-grained quartz sand, poorly to well-sorted.

Lithology: beach sand; dune sand